Sample records for charr salvelinus alpinus

  1. Experimental evidence for paternal effects on offspring growth rate in Arctic charr (Salvelinus alpinus)


    Eilertsen, Eirik Mack; Bårdsen, Bård-Jørgen; Liljedal, Ståle; Rudolfsen, Geir; Folstad, Ivar


    Sexual selection theory predicts that females should choose males that signal viability and quality. However, few studies have found fitness benefits among females mating with highly ornamented males. Here, we use Arctic charr (Salvelinus alpinus), a teleost fish with no parental care, to investigate whether females could gain fitness benefits by mating with highly ornamented and large-sized males. Carotenoid-based coloration signalled by males during spawning is believed to be an indicator o...

  2. PCB impairs smoltification and seawater performance in anadromous Arctic charr (Salvelinus alpinus) (United States)

    Jorgensen, E.H.; Aas-Hansen, O.; Maule, A.G.; Strand, J.E.T.; Vijayan, M.M.


    The impacts of polychlorinated biphenyl (PCB) exposure on smoltification and subsequent seawater performance were investigated in hatchery-reared, anadromous Arctic charr (Salvelinus alpinus). The fish were subjected to a 2-month summer seawater residence, after which they were orally dosed with 0 (Control, C), 1 (Low Dose, LD) or 100 mg Aroclor 1254 kg-1 body mass (High Dose, HD) in November. They were then held in fresh water, without being fed (to mimic their natural overwintering in freshwater), until they had smolted in June the next year. The smolts were then transferred to seawater and fed to mimic their summer feeding residence in seawater, followed by a period without food in freshwater from August until maturation in October. Compared with C and LD charr, the HD charr had either a transient or a permanent reduction in plasma growth hormone, insulin-like growth factor-1, and thyroxin and triiodothyronine titers during the period of smoltification. These hormonal alterations in the HD charr corresponded with impaired hyposmoregulatory ability in May and June, as well as reduced growth rate and survival after transference to seawater. Consequently, fewer fish in the HD group matured in October compared to the other two treatments. The HD fish had a liver PCB concentration ranging between 14 and 42 mg kg-1 wet mass, whereas there were similar, and very low, liver PCB concentrations in LD and C fish throughout the smolting period. Our findings suggest that PCB might compromise mechanisms important for fitness in a fish species living in an extreme environment. ?? 2004 Elsevier Inc. All rights reserved.

  3. Experimental evidence for paternal effects on offspring growth rate in Arctic charr (Salvelinus alpinus). (United States)

    Eilertsen, Eirik Mack; Bårdsen, Bård-Jørgen; Liljedal, Ståle; Rudolfsen, Geir; Folstad, Ivar


    Sexual selection theory predicts that females should choose males that signal viability and quality. However, few studies have found fitness benefits among females mating with highly ornamented males. Here, we use Arctic charr (Salvelinus alpinus), a teleost fish with no parental care, to investigate whether females could gain fitness benefits by mating with highly ornamented and large-sized males. Carotenoid-based coloration signalled by males during spawning is believed to be an indicator of good genes for this species. Paternal effects on offspring size (body length and dry body mass) were examined experimentally by crossing eggs and sperm in vitro from 12 females and 24 males in a split-brood design and raising larvae to 30 days past hatching. We clearly demonstrated that there was a relationship between offspring size and paternal coloration. However, a negative interaction between paternal length and coloration was evident for offspring length, indicating that positive effects of paternal coloration were only present for smaller males. Thus, the red spawning coloration of the male Arctic charr seems to be an indicator of good genes, but the effect of paternal coloration on offspring length, an indicator of 'offspring quality', is size dependent.

  4. The genetic basis of salinity tolerance traits in Arctic charr (Salvelinus alpinus

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    Glebe Brian


    Full Text Available Abstract Background The capacity to maintain internal ion homeostasis amidst changing conditions is particularly important for teleost fishes whose reproductive cycle is dependent upon movement from freshwater to seawater. Although the physiology of seawater osmoregulation in mitochondria-rich cells of fish gill epithelium is well understood, less is known about the underlying causes of inter- and intraspecific variation in salinity tolerance. We used a genome-scan approach in Arctic charr (Salvelinus alpinus to map quantitative trait loci (QTL correlated with variation in four salinity tolerance performance traits and six body size traits. Comparative genomics approaches allowed us to infer whether allelic variation at candidate gene loci (e.g., ATP1α1b, NKCC1, CFTR, and cldn10e could have underlain observed variation. Results Combined parental analyses yielded genome-wide significant QTL on linkage groups 8, 14 and 20 for salinity tolerance performance traits, and on 1, 19, 20 and 28 for body size traits. Several QTL exhibited chromosome-wide significance. Among the salinity tolerance performance QTL, trait co-localizations occurred on chromosomes 1, 4, 7, 18 and 20, while the greatest experimental variation was explained by QTL on chromosomes 20 (19.9%, 19 (14.2%, 4 (14.1% and 12 (13.1%. Several QTL localized to linkage groups exhibiting homeologous affinities, and multiple QTL mapped to regions homologous with the positions of candidate gene loci in other teleosts. There was no gene × environment interaction among body size QTL and ambient salinity. Conclusions Variation in salinity tolerance capacity can be mapped to a subset of Arctic charr genomic regions that significantly influence performance in a seawater environment. The detection of QTL on linkage group 12 was consistent with the hypothesis that variation in salinity tolerance may be affected by allelic variation at the ATP1α1b locus. IGF2 may also affect salinity tolerance

  5. Changes in arterial oxygen tension and physiological status in resting, unrestrained Arctic charr Salvelinus alpinus (L.) exposed to mild hypoxia and hyperoxia. (United States)

    Karlsson, A; Rosseland, B O; Thorarensen, H; Kiessling, A


    In arctic charr Salvelinus alpinus, arterial blood partial pressures of oxygen (PaO2) and carbon dioxide increased with increasing water oxygen tension (PwO2), while the water to arterial PO2 difference (PwO2-PaO2) did not change in relation to PwO2.

  6. Seasonal Differences in Relative Gene Expression of Putative Central Appetite Regulators in Arctic Charr (Salvelinus alpinus Do Not Reflect Its Annual Feeding Cycle.

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    Anja Striberny

    Full Text Available The highly seasonal anadromous Arctic charr (Salvelinus alpinus was used to investigate the possible involvement of altered gene expression of brain neuropeptides in seasonal appetite regulation. Pro-opiomelanocortin (POMCA1, POMCA2, Cocaine and amphetamine regulated transcript (CART, Agouti related Peptide (AgRP, Neuropeptide Y (NPY and Melanocortin Receptor 4 (MC4-R genes were examined. The function of centrally expressed Leptin (Lep in fish remains unclear, so Lep (LepA1, LepA2 and Leptin Receptor (LepR genes were included in the investigation. In a ten months study gene expression was analysed in hypothalamus, mesencephalon and telencephalon of immature charr held under natural photoperiod (69°38'N and ambient temperature and given excess feed. From April to the beginning of June the charr did not feed and lost weight, during July and August they were feeding and had a marked increase in weight and condition factor, and from November until the end of the study the charr lost appetite and decreased in weight and condition factor. Brain compartments were sampled from non-feeding charr (May, feeding charr (July, and non-feeding charr (January. Reverse transcription real-time quantitative PCR revealed temporal patterns of gene expression that differed across brain compartments. The non-feeding charr (May, January had a lower expression of the anorexigenic LepA1, MC4-R and LepR in hypothalamus and a higher expression of the orexigenic NPY and AgRP in mesencephalon, than the feeding charr (July. In the telencephalon, LepR was more highly expressed in January and May than in July. These results do not indicate that changes in central gene expression of the neuropeptides investigated here directly induce seasonal changes in feeding in Arctic charr.

  7. Effects of microbe- and mussel-based diets on the gut microbiota in Arctic charr (Salvelinus alpinus

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    Andreas Nyman


    Lactic acid bacteria were a dominant fraction of the intestinal microbiota in Arctic charr. Microbial based feeds were associated with similar changes in microbiota composition, but contrasting to the fish-meal based reference diet. Microbiota composition was similar in the proximal and distal gut, but dietary responses were specific to gut segment.

  8. Influence of o'p-DDD on the physiological response to stress in Arctic charr (Salvelinus alpinus). (United States)

    Jørgensen, E H; Balm, P H; Christiansen, J S; Plotitsyna, N; Ingebrigtsen, K


    Various toxicants have previously been held responsible for an impaired capacity of fish from polluted environments to elevate their cortisol levels in response to stress. In the present study we investigated the responses to stress in o'p-DDD [2-(chlorophenyl)-2-(4-chlorphenyl)-1,1-dichloroethane] exposed (given a single, oral dose of 75 mg o'p-DDD/kg fish) and unexposed Arctic charr. After o'p-DDD administration fish were left undisturbed and without being fed for 28 days, when they were subjected to an acute handling stress. At 1, 3, 7 and 23 h following stress, primary (ACTH and cortisol secretion) and secondary (plasma Cl levels and energy mobilisation) components of the stress response were monitored. As the nutritional state of wild fish may influence this potential biomarker response, the fish had been subjected to a restricted feed ration prior to o'p-DDD administration in order to obtain marked within-group variations in condition factor. No effects of o'p-DDD were observed on post-stress hormone secretion (i.e. peak post-stress plasma ACTH and cortisol levels), nor on plasma chloride levels. However, other results obtained provided evidence for a metabolic depression by o'p-DDD, witnessed by consistently lower plasma glucose levels before and after stress in these contaminated fish. This may be related to the finding that during the 30-day period between o'p-DDD administration and stress treatment, toxicant treated fish lost less weight in comparison to their sham-treated counterparts. Nutritional state did not appear to influence the performance of the charr in the present experiment, as correlations between the parameters measured and condition factor or lipid contents on an individual basis in all cases turned out non significant. Overall, the results contrast with those of previous in vivo and in vitro studies on fish, which concluded that comparable headkidney o'p-DDD levels impaired interrenal steroidogenesis. Although we conclude that the effects

  9. The behavioural repertoire of Arctic charr (Salvelinus alpinus (L.)) in captivity: A case study for testing ethogram completeness and reducing observer effects


    Bolgan, Marta; O'Brien, Joanne; Gammell, Martin


    In the last 20 years, research has been directed towards possible differences in the mating behaviour of species belonging to the Salmonidae family that may reproductively isolate wild populations from escaped hatchery or farmed fish. Despite these studies, a detailed description of the overall behavioural repertoire of Salmonidae species from wild and farmed environments is still lacking. Furthermore, although Arctic charr has been described as the most variable between all vertebrate specie...

  10. Flume length and post-exercise impingement affect anaerobic metabolism in brook charr Salvelinus fontinalis. (United States)

    Tudorache, C; O'Keefe, R A; Benfey, T J


    The effect of flume length and impingement time on post-exercise lactate concentrations in brook charr Salvelinus fontinalis were examined. Swimming in longer flumes increased lactate concentrations, as does impingement after swimming in short flumes.

  11. Differentiation at the MHCIIα and Cath2 loci in sympatric Salvelinus alpinus resource morphs in Lake Thingvallavatn.

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    Kalina H Kapralova

    Full Text Available Northern freshwater fish may be suitable for the genetic dissection of ecological traits because they invaded new habitats after the last ice age (∼10.000 years ago. Arctic charr (Salvelinus alpinus colonizing streams and lakes in Iceland gave rise to multiple populations of small benthic morphotypes, often in sympatry with a pelagic morphotype. Earlier studies have revealed significant, but subtle, genetic differentiation between the three most common morphs in Lake Thingvallavatn. We conducted a population genetic screen on four immunological candidate genes Cathelicidin 2 (Cath2, Hepcidin (Hamp, Liver expressed antimicrobial peptide 2a (Leap-2a, and Major Histocompatibility Complex IIα (MHCIIα and a mitochondrial marker (D-loop among the three most common Lake Thingvallavatn charr morphs. Significant differences in allele frequencies were found between morphs at the Cath2 and MHCIIα loci. No such signal was detected in the D-loop nor in the other two immunological genes. In Cath2 the small benthic morph deviated from the other two (FST  = 0.13, one of the substitutions detected constituting an amino acid replacement polymorphism in the antimicrobial peptide. A more striking difference was found in the MHCIIα. Two haplotypes were very common in the lake, and their frequency differed greatly between the morphotypes (from 22% to 93.5%, FST  = 0.67. We then expanded our study by surveying the variation in Cath2 and MHCIIα in 9 Arctic charr populations from around Iceland. The populations varied greatly in terms of allele frequencies at Cath2, but the variation did not correlate with morphotype. At the MHCIIα locus, the variation was nearly identical to the variation in the two benthic morphs of Lake Thingvallavatn. The results are consistent with a scenario where parts of the immune systems have diverged substantially among Arctic charr populations in Iceland, after colonizing the island ∼10.000 years ago.

  12. Distribution of Po-210 and Pb-210 in Arctic Char (Salvelinus alpinus) from an Arctic freshwater lake

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    Gwynn, J.P.; Rudolfsen, G. [Norwegian Radiation Protection Authority, The Fram Centre, Tromsoe (Norway)


    There is little information available with regard to the accumulation of Po-210 and Pb-210 by freshwater fish in natural freshwater systems despite the potential for relevant ingestion doses to man. This is maybe of particular pertinence for certain population groups where freshwater fish are an important dietary food item. Equally, it is important to understand the body distributions of these naturally occurring radionuclides to quantify the resulting doses to different tissues and organs of freshwater fish. With regard to the latter, it is important to consider not only the doses arising from bio-accumulated Po-210 and Pb-210 in various body compartments but additionally the internal dose from unabsorbed Po-210 and Pb-210 in the digestive tract. In this study, activity concentrations of Po-210 and Pb-210 were determined in muscle and various internal organs of Arctic Charr (Salvelinus alpinus) sampled from a lake in the Norwegian Arctic (69 deg. 4' N, 19 deg. 20' E). Observed activity concentrations of Po-210 and Pb-210 in different tissues will be discussed in relation to physiological parameters and ambient lake water activity concentrations. Results from this study will be compared to two similar studies conducted in freshwater systems where elevated activity concentrations of these radionuclides have been observed. Ingestion dose rates to man and effective absorbed dose rates to different tissues and organs of Arctic Charr from Po-210 and Pb-210 will be derived and compared to those from observed activity concentrations of the anthropogenic radionuclide Cs-137. (authors)

  13. Comparative transcriptomics of anadromous and resident brook charr Salvelinus fontinalis before their first salt water transition

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    Marylène BOULET, Éric NORMANDEAU, Bérénice BOUGAS, Céline AUDET,Louis BERNATCHEZ


    Full Text Available Most salmonid taxa have an anadromous life history strategy, whereby fish migrate to saltwater habitats for a growth period before returning to freshwater habitats for spawning. Moreover, several species are characterized by different life history tactics whereby resident and anadromous forms may occur in genetically differentiated populations within a same species, as well as polymorphism within a population. The molecular mechanisms underlying the physiological differences between anadromous and resident forms during the first transition from freshwater to saltwater environments are only partially understood. Insofar research has typically focused on species of the genus Salmo. Here, using a 16,000 cDNA array, we tested the hypothesis that anadromous brook charr Salvelinus fontinalis are characterized by differences in their transcriptome relative to resident brook charr before the anadromous fish migration. Families originating from parapatric populations of anadromous and resident charr were reared in controlled environments mimicking natural temperature and photoperiod, and sampled in spring, while still in fresh water. While anadromous and resident charr showed similar transcriptome profiles in white muscle, they were characterized by striking differences in their gill transcriptome profiles. Genes that were upregulated in the gills of anadromous charr were principally involved in metabolism (mitochondrial electron transport chain, glucose metabolism, and protein synthesis, development (tissue differentiation and innate immunity. We discuss the nature of these transcriptomic differences in relation to molecular mechanisms underlying the expression of anadromous and resident life history tactics and suggest that the anadromous charr express some of the molecular processes present in other migratory salmonids [Current Zoology 58 (1: 158–170, 2012].

  14. Comparative transcriptomics of anadromous and resident brook charr Salvelinus fontinalis before their first salt water transition

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    Marylène BOULET; (E)ric NORMANDEAU; Bérénice BOUGAS; Cé1ine AUDET; Louis BERNATCHEZ


    Most salmonid taxa have an anadromous life history strategy,whereby fish migrate to saltwater habitats for a growth period before returning to freshwater habitats for spawning.Moreover,several species are characterized by different life history tactics whereby resident and anadromous forms may occur in genetically differentiated populations within a same species,as well as polymorphism within a population.The molecular mechanisms underlying the physiological differences between anadromous and resident forms during the first transition from freshwater to saltwater environments are only partially understood.Insofar research has typically focused on species of the genus Salmo.Here,using a 16,000 cDNA array,we tested the hypothesis that anadromous brook charr Salvelinus fontinalis are characterized by differences in their transcriptome relative to resident brook charr before the anadromous fish migration.Families originating from parapatric populations of anadromous and resident charr were reared in controlled environments mimicking natural temperature and photoperiod,and sampled in spring,while still in fresh water.While anadromous and resident charr showed similar transcriptome profdes in white muscle,they were characterized by striking differences in their gill transcriptome profiles.Genes that were upregulated in the gills of anadromous charr were principally involved in metabolism (mitochondrial electron transport chain,glucose metabolism,and protein synthesis),development (tissue differentiation) and innate immunity.We discuss the nature of these transcriptomic differences in relation to molecular mechanisms underlying the expression of anadromous and resident life history tactics and suggest that the anadromous chart express some of the molecular processes present in other migratory salmonids [Current Zoology 58 (1):158-170,2012].

  15. Life history differences between fat and lean morphs of lake charr (Salvelinus namaycush) in Great Slave Lake, Northwest Territories, Canada (United States)

    Hansen, Michael J.; Nate, Nancy A.; Chavarie, Louise; Muir, Andrew M.; Zimmerman, Mara S.; Krueger, Charles C.


    Life history characteristics (size, age, plumpness, buoyancy, survival, growth, and maturity) were compared between fat and lean morphs of lake charr Salvelinus namaycush in Great Slave Lake, Canada, to determine if differences may reflect effects of resource polymorphism. Lake charr were sampled using graded-mesh gill nets set in three depth strata. Of 236 lake charr captured, 122 were a fat morph and 114 were a lean morph. Males and females did not differ from each other in any attributes for either fat or lean morphs. The fat morph averaged 15 mm longer, 481 g heavier, and 4.7 years older than the lean morph. The fat morph averaged 26% heavier and 48% more buoyant at length than the lean morph. Survival of the fat morph was 1.7% higher than that of the lean morph. The fat morph grew at a slower annual rate to a shorter asymptotic length than the lean morph. Fat and lean morphs matured at similar lengths and ages. We concluded that the connection between resource polymorphism and life histories in lean versus fat lake charr suggests that morph-specific restoration objectives may be needed in lakes where lake charr diversity is considered to be a restoration goal.

  16. Genetic analysis of sympatric char populations in western Alaska: Arctic char (Salvelinus alpinus) and Dolly Varden (Salvelinus malma) are not two sides of the same coin. (United States)

    Taylor, E B; Lowery, E; Lilliestråle, A; Elz, A; Quinn, T P


    The North Pacific Ocean has been of great significance to understanding biogeography and speciation in temperate faunas, including for two species of char (Salmonidae: Salvelinus) whose evolutionary relationship has been controversial. We examined the morphology and genetics (microsatellite and mitochondrial DNA) of Arctic char (Salvelinus alpinus) and Dolly Varden char (Salvelinus malma) in lake systems in western Alaska, the eastern and western Arctic, and south of the Alaskan Peninsula. Morphologically, each lake system contained two forms: one (Arctic char) largely confined to lake habitats and characterized by greater numbers of pyloric caeca, gill rakers, and shallower bodies, and another (Dolly Varden) predominated in adjacent stream habitats and was characterized by fewer pyloric caeca, gill rakers, and deeper bodies. MtDNA partial (550 bp) d-loop sequences of both taxa were interspersed with each other within a single 'Bering' clade and demographic inferences suggested historical gene flow from Dolly Varden to Arctic char had occurred. By contrast, the taxa were strongly differentiated in sympatry across nine microsatellite loci in both lakes. Our data show that the two taxa are highly genetically distinct in sympatry, supporting their status as valid biological species, despite occasional hybridization. The interaction between these species highlights the importance of the North Pacific, and Beringia in particular, as an evolutionary wellspring of biodiversity.

  17. Contaminant loading in remote Arctic lakes affects cellular stress-related proteins expression in feral charr. (United States)

    Wiseman, Steve; Jorgensen, Even H.; Maule, Alec G.; Vijayan, Mathilakath M.


    The remote Arctic lakes on Bjornoya Island, Norway, offer a unique opportunity to study possible affect of lifelong contaminant exposure in wild populations of landlocked Arctic charr (Salvelinus alpinus). This is because Lake Ellasjoen has persistent organic pollutant (POP) levels that are significantly greater than in the nearby Lake Oyangen. We examined whether this differential contaminant loading was reflected in the expression of protein markers of exposure and effect in the native fish. We assessed the expressions of cellular stress markers, including cytochrome P4501A (Cyp1A), heat shock protein 70 (hsp70), and glucocorticoid receptor (GR) in feral charr from the two lakes. The average polychlorinated biphenyl (PCB) load in the charr liver from Ellasjoen was approximately 25-fold higher than in individuals from Oyangen. Liver Cyp1A protein expression was significantly higher in individuals from Ellasjoen compared with Oyangen, confirming differential PCB exposure. There was no significant difference in hsp70 protein expression in charr liver between the two lakes. However, brain hsp70 protein expression was significantly elevated in charr from Ellasjoen compared with Oyangen. Also, liver GR protein expression was significantly higher in the Ellasjoen charr compared with Oyangen charr. Taken together, our results suggest changes to cellular stress-related protein expression as a possible adaptation to chronic-contaminant exposure in feral charr in the Norwegian high-Arctic.

  18. Low levels of hybridization between sympatric Arctic char (Salvelinus alpinus) and Dolly Varden char (Salvelinus malma) highlights their genetic distinctiveness and ecological segregation. (United States)

    May-McNally, Shannan L; Quinn, Thomas P; Taylor, Eric B


    Understanding the extent of interspecific hybridization and how ecological segregation may influence hybridization requires comprehensively sampling different habitats over a range of life history stages. Arctic char (Salvelinus alpinus) and Dolly Varden (S. malma) are recently diverged salmonid fishes that come into contact in several areas of the North Pacific where they occasionally hybridize. To better quantify the degree of hybridization and ecological segregation between these taxa, we sampled over 700 fish from multiple lake (littoral and profundal) and stream sites in two large, interconnected southwestern Alaskan lakes. Individuals were genotyped at 12 microsatellite markers, and genetic admixture (Q) values generated through Bayesian-based clustering revealed hybridization levels generally lower than reported in a previous study (Dolly Varden and Arctic char tended to make different use of stream habitats with the latter apparently abandoning streams for lake habitats after 2-3 years of age. Our results support the distinct biological species status of Dolly Varden and Arctic char and suggest that ecological segregation may be an important factor limiting opportunities for hybridization and/or the ecological performance of hybrid char.

  19. Subcellular distribution of trace elements and liver histology of landlocked Arctic char (Salvelinus alpinus) sampled along a mercury contamination gradient. (United States)

    Barst, Benjamin D; Rosabal, Maikel; Campbell, Peter G C; Muir, Derek G C; Wang, Xioawa; Köck, Günter; Drevnick, Paul E


    We sampled landlocked Arctic char (Salvelinus alpinus) from four lakes (Small, 9-Mile, North, Amituk) in the Canadian High Arctic that span a gradient of mercury contamination. Metals (Hg, Se, Tl, and Fe) were measured in char tissues to determine their relationships with health indices (relative condition factor and hepatosomatic index), stable nitrogen isotope ratios, and liver histology. A subcellular partitioning procedure was employed to determine how metals were distributed between potentially sensitive and detoxified compartments of Arctic char livers from a low- and high-mercury lake (Small Lake and Amituk Lake, respectively). Differences in health indices and metal concentrations among char populations were likely related to differences in feeding ecology. Concentrations of Hg, Se, and Tl were highest in the livers of Amituk char, whereas concentrations of Fe were highest in Small and 9-Mile char. At the subcellular level we found that although Amituk char had higher concentrations of Tl in whole liver than Small Lake char, they maintained a greater proportion of this metal in detoxified fractions, suggesting an attempt at detoxification. Mercury was found mainly in potentially sensitive fractions of both Small and Amituk Lake char, indicating that Arctic char are not effectively detoxifying this metal. Histological changes in char livers, mainly in the form of melano-macrophage aggregates and hepatic fibrosis, could be linked to the concentrations and subcellular distributions of essential or non-essential metals.

  20. Use of the Rigor Mortis Process as a Tool for Better Understanding of Skeletal Muscle Physiology: Effect of the Ante-Mortem Stress on the Progression of Rigor Mortis in Brook Charr (Salvelinus fontinalis). (United States)

    Diouf, Boucar; Rioux, Pierre


    Presents the rigor mortis process in brook charr (Salvelinus fontinalis) as a tool for better understanding skeletal muscle metabolism. Describes an activity that demonstrates how rigor mortis is related to the post-mortem decrease of muscular glycogen and ATP, how glycogen degradation produces lactic acid that lowers muscle pH, and how…

  1. [Peculiarities of the parasitofauna of Atlantic salmon parr (Salmo salar L.), brown trout (Salmo truttae L.), and char (Salvelinus alpinus L.) in the Utsjoki River system (Northern Finland)]. (United States)

    Ieshko, E P; Barskaia, Iu Iu; Lebedeva, D I; Novokhatskaia, O V; Kaukoranta, M; Niemela, E


    Data on the parasite diversity in Salmonidae fish parr from different parts of the Utsjoki River obtained during 1993-1995 and 2006-2007 are presented. Three fish species, Salmo salar L., S. truttae L., and Salvelinus alpinus L., were examined on the presence of helminthes. Twenty species of salmon parasites were found, the majority of which are the parasites with complicated life cycles. Infusorians C apriniana piscium, myxosporidia Chloromyxum januaricus and Myxobolus neurobius, metacercaria of the genera Diplostomum and Apatemon, and the nematode Raphidascaris acus larvae were the most numerous in salmon parasite fauna. Brown trout had the most number of specific parasite species, whereas char was infested by protozoan parasites only.

  2. Mitochondrial DNA population structure of the white-spotted Charr (Salvelinus leucomaenis) in the Lake Biwa water system. (United States)

    Kikko, Takeshi; Kuwahara, Masayuki; Iguchi, Kei'ichiro; Kurumi, Seiji; Yamamoto, Shoichiro; Kai, Yoshiaki; Nakayama, Kouji


    A phylogeographic analysis of mitochondrial DNA sequences was performed in order to elucidate the origin, dispersal process, and genetic structure of white-spotted charr in the Lake Biwa water system. Two haplotypes were most common in the Lake Biwa water system, and were also common in the adjacent inlet rivers of the Sea of Japan. These results suggest that in the glacial periods of the Pleistocene, white-spotted charr dispersed into the northern inlet rivers of Lake Biwa from adjacent inlet rivers of the Sea of Japan by watershed exchanges, colonizing the whole of the Lake Biwa water system. Mitochondrial DNA diversity contrasted sharply between the western and eastern parts of the system, suggesting that the populations in the western part might be more reduced than those in the eastern part in relation to the smaller habitat size. The high overall FST estimate (0.50), together with pairwise comparisons of FST, indicated significant genetic divergence between populations due to isolation and small population size. Hierarchical analysis (AMOVA) also showed that genetic variation was more pronounced among regions (28.39%) and among populations within regions (47.24%) than within populations (24.37%). This suggests that each population in and around the Lake Biwa water system should be treated as a significant unit for conservation and management.

  3. Phylogeography of the salmonid fish, Dolly Varden Salvelinus malma: multiple glacial refugia in the North Pacific Rim. (United States)

    Yamamoto, Shoichiro; Maekawa, Koji; Morita, Kentaro; Crane, Penelope A; Oleinik, Alla G


    The geographic distribution pattern of mitochondrial DNA (control region) sequence polymorphisms from 73 populations of a salmonid fish, Dolly Varden Salvelinus malma, over most of its range in the North Pacific rim, was examined to assess how its spatial population genetic structure has been molded. The observed 68 haplotypes were grouped into three main lineages, which correspond to western, central, and eastern regions in the North Pacific. The two outlier-haplotype groups gave close agreement with DNA types from two congeneric species, white-spotted charr S. leucomaenis and Arctic charr S. alpinus, respectively. These results suggest that the present-day genetic structure of S. malma reflects historical patterns of isolation and re-colonization, and also historical hybridization with co-distributed species. We also placed the haplotypes of S. malma within our study areas into a pre-existing evolutionary relationship of S. alpinus and S. malma throughout the Northern Hemisphere. Phylogenetic analysis revealed that the Western Lineage S. malma was basal to all other lineages of S. malma and S. alpinus. Our data serve as a biogeographic hypothesis for salmonid fishes that the Sea of Japan and/or Sea of Okhotsk regions represents a place of origin for S. malma and S. alpinus groups currently distributed in circumpolar regions.

  4. The influence of parental effects on transcriptomic landscape during early development in brook charr (Salvelinus fontinalis, Mitchill). (United States)

    Bougas, B; Audet, C; Bernatchez, L


    Parental effects represent an important source of variation in offspring phenotypes. Depending on the specific mechanisms involved, parental effects may be caused to different degrees by either the maternal or the paternal parent, and these effects may in turn act at different stages of development. To detect parental effects acting on gene transcription regulation and length phenotype during ontogeny, the transcriptomic profiles of two reciprocal hybrids from Laval × Rupert and Laval × Domestic populations of brook charr were compared at hatching, yolk sac resorption and 15 weeks after exogenous feeding. Using a salmonid cDNA microarray, our results show that parental effects modulated gene expression among reciprocal hybrids only at the yolk sac resorption stage. In addition, Laval × Domestic and Laval × Rupert reciprocal hybrids differed in the magnitude of theses parental effects, with 199 and 630 differentially expressed transcripts, respectively. This corresponds to a maximum of 18.5% of the analyzed transcripts. These transcripts are functionally related to cell cycle, nucleic acid metabolism and intracellular protein traffic, which is consistent with observed differences associated with embryonic development and growth differences in other fish species. Our results thus illustrate how parental effects on patterns of gene transcription seem dependent on the genetic architecture of the parents. In addition, in absence of transcriptional differences, non-transcript deposits in the yolk sac could contribute to the observed length differences among the reciprocal hybrids before yolk sac resorption.

  5. Aroclor 1254 exposure reduces disease resistance and innate immune responses in fasted arctic charr (United States)

    Maule, A.G.; Jorgensen, E.H.; Vijayan, M.M.; Killie, J.-E.A.


    To examine the immunological impacts of polychlorinated biphenyls (PCBs) in an environmentally relevant way, we orally contaminated Arctic charr (Salvelinus alpinus) with Aroclor 1254. After contamination, fish were either fed (0 and 100 mg Aroclor 1254 kg-1 fish wt) or fasted (0, 1, 10, and 100 mg kg-1) to mimic cycles of feeding-fasting experienced by Arctic animals. After four months, PCB concentrations in muscle were the same in fasted and fed fish; however, PCBs in kidneys of fed fish were 33 to 50% of those in fasted fish. Arctic charr were exposed to Aeromonas salmonicida, the bacteria responsible for furunculosis, by cohabitation with infected conspecifics. Fasted fish had a significant trend toward lower survival with higher dose of PCBs - from 68% in controls to 48% in treatment involving 100 mg kg-1. Independent of PCB contamination, fed fish had the lowest survival; we attribute this to stress associated with establishing and maintaining feeding hierarchies. A significant decrease in the activity of lysozyme was observed in skin mucus, as was hemagglutination ability of a putative rhamnose lectin in fasted, but not in fed, PCB-treated fish. These results demonstrate the immunosuppressive effects of PCBs on Arctic charr, and they illustrate the importance of considering environmentally relevant nutritional status in ecotoxicological studies.

  6. The influence of gene-environment interactions on GHR and IGF-1 expression and their association with growth in brook charr, Salvelinus fontinalis (Mitchill

    Directory of Open Access Journals (Sweden)

    Blier Pierre


    Full Text Available Abstract Background Quantitative reaction norm theory proposes that genotype-by-environment interaction (GxE results from inter-individual differences of expression in adaptive suites of genes in distinct environments. However, environmental norms for actual gene suites are poorly documented. In this study, we investigated the effects of GxE interactions on levels of gene transcription and growth by documenting the impact of rearing environment (freshwater vs. saltwater, sex and genotypic (low vs. high estimated breeding value EBV effects on the transcription level of insulin-like growth factor (IGF-1 and growth hormone receptor (GHR in brook charr (Salvelinus fontinalis. Results Males grew faster than females (μ♀ = 1.20 ± 0.07 g·d-1, μ♂ = 1.46 ± 0.06 g·d-1 and high-EBV fish faster than low-EBV fish (μLOW = 0.97 ± 0.05 g·d-1, μHIGH = 1.58 ± 0.07 g·d-1; p FW = 1.52 ± 0.07 g·d-1, μSW = 1.15 ± 0.06 g·d-1, yet GHR mRNA transcription level was significantly higher in saltwater than in freshwater (μSW = 0.85 ± 0.05, μFW = 0.61 ± 0.05. The ratio of actual growth to units in assayed mRNA ('individual transcript efficiency', iTE; g·d-1·u-1 also differed among EBV groups (μLOW = 2.0 ± 0.24 g·d-1·u-1; μHIGH = 3.7 ± 0.24 g·d-1·u-1 and environments (μSW = 2.0 ± 0.25 g·d-1·u-1; μFW = 3.7 ± 0.25 g·d-1·u-1 for GHR. Males had a lower iTE for GHR than females (μ♂ = 2.4 ± 0.29 g·d-1·u-1; μ♀ = 3.1 ± 0.23 g·d-1·u-1. There was no difference in IGF-1 transcription level between environments (p > 0.7 or EBV groups (p > 0.15 but the level of IGF-1 was four times higher in males than females (μ♂ = 2.4 ± 0.11, μ♀ = 0.58 ± 0.09; p ♂ = 1.3 ± 0.59 g·d-1·u-1; μ♀ = 3.9 ± 0.47 g·d-1·u-1, salinities (μSW = 2.3 ± 0.52 g·d-1·u-1; μFW = 3.7 ± 0.53 g·d-1·u-1 and EBV-groups (μLOW = 2.4 ± 0.49 g·d-1·u-1; μHIGH = 3.8 ± 0.49 g·d-1·u-1. Interaction between EBV-group and environment was detected for

  7. Fasting modifies Aroclor 1254 impact on plasma cortisol, glucose and lactate responses to a handling disturbance in Arctic charr (United States)

    Jorgensen, E.H.; Vijayan, M.M.; Aluru, N.; Maule, A.G.


    Integrated effects of polychlorinated biphenyl (PCB) and nutritional status on responses to handling disturbance were investigated in the Arctic charr (Salvelinus alpinus). The fish were orally contaminated with Aroclor 1254 and held either with or without food for 5 months before they were subjected to a 10-min handling disturbance. Food-deprived fish were given 0, 1, 10 or 100 mg PCB kg-1 and the fed fish 0 or 100 mg PCB kg-1. Plasma cortisol, glucose and lactate levels were measured at 0 (pre-handling), 1, 3, 6 and 23 h after the handling disturbance. Food-deprived control fish had elevated plasma cortisol levels compared with fed fish before handling. These basal cortisol levels were suppressed by PCB in food-deprived fish, and elevated by PCB in fed fish. The immediate cortisol and glucose responses to handling disturbance were suppressed by PCB in a dose-dependent way in food-deprived fish. Although these responses were also lowered by PCB in the fed fish, the effect was much less pronounced than in food-deprived fish. There were only minor effects on plasma lactate responses. Our findings suggest that the stress responses of the Arctic charr are compromised by PCB and that the long-term fasting, typical of high-latitude fish, makes these species particularly sensitive to organochlorines such as PCB. ?? 2002 Elsevier Science Inc. All rights reserved.

  8. Mercury and methylmercury concentrations in high altitude lakes and fish (Arctic charr) from the French Alps related to watershed characteristics. (United States)

    Marusczak, Nicolas; Larose, Catherine; Dommergue, Aurélien; Paquet, Serge; Beaulne, Jean-Sébastien; Maury-Brachet, Régine; Lucotte, Marc; Nedjai, Rachid; Ferrari, Christophe P


    Total mercury (THg) and methylmercury (MeHg) concentrations were measured in the muscle of Arctic charr (Salvelinus alpinus) and in the water column of 4 lakes that are located in the French Alps. Watershed characteristics were determined (6 coverage classes) for each lake in order to evaluate the influence of watershed composition on mercury and methylmercury concentrations in fish muscle and in the water column. THg and MeHg concentrations in surface water were relatively low and similar among lakes and watershed characteristics play a major role in determining water column Hg and MeHg levels. THg muscle concentrations for fish with either a standardized length of 220mm, a standardized age of 5 years or for individualuals did not exceed the 0.5mg kg(-1) fish consumption advisory limit established for Hg by the World Health Organization (WHO, 1990). These relatively low THg concentrations can be explained by watershed characteristics, which lead to short Hg residence time in the water column, and also by the short trophic chain that is characteristic of mountain lakes. Growth rate did not seem to influence THg concentrations in fish muscles of these lakes and we observed no relationship between fish Hg concentrations and altitude. This study shows that in the French Alps, high altitude lakes have relatively low THg and MeHg concentrations in both the water column and in Arctic charr populations. Therefore, Hg does not appear to present a danger for local populations and the fishermen of these lakes.

  9. Long-term fasting in the anadromous Arctic charr is associated with downregulation of metabolic enzyme activity and upregulation of leptin A1 and SOCS expression in the liver. (United States)

    Jørgensen, Even Hjalmar; Martinsen, Mads; Strøm, Vidar; Hansen, Kristin Elisa Ruud; Ravuri, Chandra Sekhar; Gong, Ningping; Jobling, Malcolm


    The life strategy of the anadromous Arctic charr (Salvelinus alpinus) includes several months of voluntary fasting during overwintering in freshwater, leading to emaciation prior to seawater migration in spring. In this study we compared changes in condition, substrate utilization and liver metabolism between captive anadromous charr subjected to food deprivation during late winter and spring, and conspecifics fed in excess. In March, nine out of the 10 sampled fed fish had not eaten, indicating that they were in a voluntary anorexic state. In June, the fed fish were eating and all had higher body mass, condition factor and adiposity than in March. In fasted fish there were only small decreases in body mass, condition factor and adiposity between March and May, but all these parameters decreased markedly from May to June. The fasted fish were depleted in fat and glycogen in June, had suppressed activity of hepatic enzymes involved in lipid metabolism (G6PDH and HOAD) and seemed to rely on protein-derived glucose as a major energy source. This was associated with upregulated liver gene expression of leptin A1, leptin A2, SOCS1, SOCS2 and SOCS3, and reduced IGF-I expression. In an in vitro study with liver slices it was shown that recombinant rainbow trout leptin stimulated SOCS1 and SOCS3 expression, but not SOCS2, IGF-I or genes of enzymes involved in lipid (G6PDH) and amino acid (AspAT) metabolism. It is concluded that liver leptin interacts with SOCS in a paracrine fashion to suppress lipolytic pathways and depress metabolism when fat stores are depleted.

  10. Challenge to the model of lake charr evolution: Shallow- and deep-water morphs exist within a small postglacial lake (United States)

    Chavarie, Louise; Muir, Andrew M.; Zimmerman, Mara S.; Baillie, Shauna M.; Hansen, Michael J.; Nate, Nancy A.; Yule, Daniel L.; Middel, Trevor; Bentzen, Paul; Krueger, Charles C.


    All examples of lake charr (Salvelinus namaycush) diversity occur within the largest, deepest lakes of North America (i.e. > 2000 km2). We report here Rush Lake (1.3 km2) as the first example of a small lake with two lake charr morphs (lean and huronicus). Morphology, diet, life history, and genetics were examined to demonstrate the existence of morphs and determine the potential influence of evolutionary processes that led to their formation or maintenance. Results showed that the huronicus morph, caught in deep-water, had a deeper body, smaller head and jaws, higher eye position, greater buoyancy, and deeper peduncle than the shallow-water lean morph. Huronicus grew slower to a smaller adult size, and had an older mean age than the lean morph. Genetic comparisons showed low genetic divergence between morphs, indicating incomplete reproductive isolation. Phenotypic plasticity and differences in habitat use between deep and shallow waters associated with variation in foraging opportunities seems to have been sufficient to maintain the two morphs, demonstrating their important roles in resource polymorphism. Rush Lake expands previous explanations for lake charr intraspecific diversity, from large to small lakes and from reproductive isolation to the presence of gene flow associated with strong ecological drivers.

  11. Quantification of 15 bile acids in lake charr feces by ultra-high performance liquid chromatography–tandem mass spectrometry (United States)

    Li, Ke; Buchinger, Tyler J.; Bussy, Ugo; Fissette, Skye D; Johnson, Nicholas; Li, Weiming


    Many fishes are hypothesized to use bile acids (BAs) as chemical cues, yet quantification of BAs in biological samples and the required methods remain limited. Here, we present an UHPLC–MS/MS method for simultaneous, sensitive, and rapid quantification of 15 BAs, including free, taurine, and glycine conjugated BAs, and application of the method to fecal samples from lake charr (Salvelinus namaycush). The analytes were separated on a C18 column with acetonitrile–water (containing 7.5 mM ammonium acetate and 0.1% formic acid) as mobile phase at a flow rate of 0.25 mL/min for 12 min. BAs were monitored with a negative electrospray triple quadrupole mass spectrometer (Xevo TQ-S™). Calibration curves of 15 BAs were linear over the concentration range of 1.00–5,000 ng/mL. Validation revealed that the method was specific, accurate, and precise. The method was applied to quantitative analysis of feces extract of fry lake charr and the food they were eating. The concentrations of analytes CA, TCDCA, TCA, and CDCA were 242.3, 81.2, 60.7, and 36.2 ng/mg, respectively. However, other taurine conjugated BAs, TUDCA, TDCA, and THDCA, were not detected in feces of lake charr. Interestingly, TCA and TCDCA were detected at high concentrations in food pellets, at 71.9 and 38.2 ng/mg, respectively. Application of the method to feces samples from lake charr supported a role of BAs as chemical cues, and will enhance further investigation of BAs as chemical cues in other fish species.

  12. Genetic structure of the Salvelinus genus chars from reservoirs of the Kuril Islands. (United States)

    Shubina, E A; Ponomareva, E V; Gritsenko, O F


    Genetic resemblance of chars Salvelinus alpinus krasheninnikovi (Salvelinus malma krasheninnikovi) of 35 samples collected in five Kuril Islands--Shumshu, Paramushir, Onekotan, Iturup, and Kunashir--has been studied by the PCR-RAPD method. In the limits of each island, both resident isolates and anadromous forms give strictly supported clusters distinct from samples from the other islands. The samples from five islands form three superclusters: the first from Kunashir and Iturup Islands, the second from Paramushir and Onekotan Islands, and the third from Shumshu Island. The possible reasons for genetic similarity of resident and anadromous forms of Dolly Varden chars inhabiting reservoirs of a definite island are considered (the founder effect, homing, limited migration).

  13. Comparative transcriptomics of anadromous and resident brook charr Salvelinus fontinalis before their first salt water transition



    Most salmonid taxa have an anadromous life history strategy, whereby fish migrate to saltwater habitats for a growth period before returning to freshwater habitats for spawning. Moreover, several species are characterized by different life history tactics whereby resident and anadromous forms may occur in genetically differentiated populations within a same species, as well as polymorphism within a population. The molecular mechanisms underlying the physiological differences between anadromou...

  14. Do stocked hatchery-reared juveniles ecologically suppress wild juveniles in Salvelinus leucomaenis? (United States)

    Nakamura, T; Doi, T


    The dominancy of semi-wild and hatchery-reared white-spotted charr Salvelinus leucomaenis juveniles was evaluated using pair-wise enclosure tests and field stocking tests. The semi-wild S. leucomaenis originated in a hatchery, being stocked into the test stream as eyed-eggs. In the pair-wise enclosure test, the semi-wild S. leucomaenis dominated the hatchery S. leucomaenis that were of a similar standard length (L(S) ). The semi-wild S. leucomaenis were subordinate to hatchery S. leucomaenis that were > 11% larger in LS . In the field stocking test, the abundance and growth of semi-wild S. leucomaenis was decreased in the presence of larger hatchery S. leucomaenis (14% larger LS ). Taken together, these results suggest that larger hatchery S. leucomaenis ecologically suppress the smaller semi-wild S. leucomaenis. Salvelinus leucomaenis juveniles that are stocked with the intention of supplementing natural populations should be < 10% larger than their wild counterparts at the time of stocking to minimize their competitive advantage. The semi-wild and hatchery S. leucomaenis used in both tests were genetically similar individuals, suggesting that the differences are due to the early rearing environment of either a natural stream or hatchery. The hatchery S. leucomaenis have lower levels of aggression as a result of selection in the hatchery rearing environment. Rearing in a natural stream from the eyed-egg stage is likely to increase their lowered aggression.

  15. [Population genetic structure of the char species of the Northern Kuril Islands and the rank of the Dolly Varden Char in the system of the genus Salvelinus (Salmonidae: Teleostei)]. (United States)

    Shubina, E A; Ponomareva, E V; Gritsenko, O F


    Analysis of the taxonomic position of most species and forms of the char (genus Salvelinus, Salmonidae: Teleostei) was made based on RAPD-PCR. The material was represented by samples from 29 populations from the Kuril Islands, coast of the Sea of Okhotsk, Kamchatka, Chukotka, Taymyr, Transbaikalia, the Kola Peninsula, Svalbard, Finland, and North America. It was shown that the genus Salvelinus splits into three well-justified clusters: (1) all the forms assigned to the Salvelinus alpinus--S. malma complex; (2) two samples of the White-Spotted Char from the Southern Kuril Islands and from Kamchatka; (3) two North American species, S. fontinalis and S. namaycush (samples of the North American species S. confluentis were absent from the collection). Analysis of the absolute values of genetic disctances of the S. alpinus--S. malma forms relative to S. leucomaenis, S. fontinalis, and S. namaycush revealed distances approaching the species rank between the following isolates: Frolikh Char, Mountain Char, Black Lake Char, Goggle-Eyed Char, and Neyva Char. Samples of Dolly Varden currently considered as "S. malma", do not constitute a separate cluster, falling within the group of the Arctic char S. alpinus. This conclusion is supported by the analysis of the results of three series of experiments by R. Phillips on ITS1 ribosome genes (Pleute et al., 1992; Phillips et al., 1995; Phillips et al., 1999). This indicates the infraspecific rank of malma within S. alpinus. Isolated populations of "Salvethymus svetovidovi" from the lake Elgygytgyn (Chukotka Peninsula) and of the char from the lake Chyornoye (Onekotan Island), recently described as S. gritzenkoi (Vasil'eva, Stygar, 2000), fell withing the S. alpinus--S. malma complex, the Onekotan char grouped together with another isolate from the same island. Comparison of genetic distances between the samples showed that the differences between the two isolated of Onekotan and migratory forms of the Kuril Islands are

  16. Dynamic Energy Budgets and Bioaccumulation: A Model for Marine Mammals and Marine Mammal Populations (United States)


    Birnbaum, and M. DeVito. 2005. Comparison of the use of a physiologically based pharmacokinetic model and a classical pharmacokinetic model for dioxin ...status on biomarker responses to PCB in the arctic charr (Salvelinus alpinus). Aquatic Toxicology 44:233-244, Kann, L. M., and K. Wishner. 1995...description of the tissue distribution and enzyme-inducing properties of 2,3,7,8-tetrachlorodibenzo-p- dioxin in the rat. Toxicology and Applied

  17. Study on Techniques of Artifical Breedingand Alevins Culture of Dolly Varden Charr (S. malma)%花羔红点鲑人工繁殖和仔鱼培育技术研究

    Institute of Scientific and Technical Information of China (English)

    黄权; 吴莉芳; 张东鸣; 李月红


    The techniques of artifical breeding and alevins culture of dolly varden charr (Salvelinus malma) were developed. Rel ationships between the size o f the parent fish and their reproductivity; developmental time of fertilized eggs and water temperture; the size of mature eggs and the time of the first feeding of alevins; and the effect of cultivated population on natural population were also discussed.%对花羔红点鲑人工繁殖和仔鱼培育技术进行了研究,并探讨了亲鱼大小与绝对繁殖力、受精卵发育时间与温度、成熟卵大小与初次摄食仔鱼大小等问题以及人工养殖群体对野生种群的影响。

  18. The influence of parental effects on transcriptomic landscape during early development in brook charr (Salvelinus fontinalis, Mitchill)



    Parental effects represent an important source of variation in offspring phenotypes. Depending on the specific mechanisms involved, parental effects may be caused to different degrees by either the maternal or the paternal parent, and these effects may in turn act at different stages of development. To detect parental effects acting on gene transcription regulation and length phenotype during ontogeny, the transcriptomic profiles of two reciprocal hybrids from Laval × Rupert an...

  19. Decomposed pairwise regression analysis of genetic and geographic distances reveals a metapopulation structure of stream-dwelling Dolly Varden charr. (United States)

    Koizumi, Itsuro; Yamamoto, Shoichiro; Maekawa, Koji


    Isolation by distance is usually tested by the correlation of genetic and geographic distances separating all pairwise populations' combinations. However, this method can be significantly biased by only a few highly diverged populations and lose the information of individual population. To detect outlier populations and investigate the relative strengths of gene flow and genetic drift for each population, we propose a decomposed pairwise regression analysis. This analysis was applied to the well-described one-dimensional stepping-stone system of stream-dwelling Dolly Varden charr (Salvelinus malma). When genetic and geographic distances were plotted for all pairs of 17 tributary populations, the correlation was significant but weak (r(2) = 0.184). Seven outlier populations were determined based on the systematic bias of the regression residuals, followed by Akaike's information criteria. The best model, 10 populations included, showed a strong pattern of isolation by distance (r(2) = 0.758), suggesting equilibrium between gene flow and genetic drift in these populations. Each outlier population was also analysed by plotting pairwise genetic and geographic distances against the 10 nonoutlier populations, and categorized into one of the three patterns: strong genetic drift, genetic drift with a limited gene flow and a high level of gene flow. These classifications were generally consistent with a priori predictions for each population (physical barrier, population size, anthropogenic impacts). Combined the genetic analysis with field observations, Dolly Varden in this river appeared to form a mainland-island or source-sink metapopulation structure. The generality of the method will merit many types of spatial genetic analyses.

  20. Laser ablation inductively coupled plasma mass spectrometric analyses of base metals in arctic char (Salvelinus alpinus) otoliths collected from a flooded base metal mine. (United States)

    Friedrich, Lisa A; Halden, Norman M


    Otoliths from arctic char recovered from the water body formed from an abandoned open-pit nickel-copper mine contain a trace element record related to the geology of the immediate watershed, past mining activity in the area, and the fish's diet. Laser ablation inductively coupled plasma mass spectrometric analyses across the annular structure of the otoliths detected trace amounts of nickel, copper, and chromium believed to be related to the metal-bearing, mafic-ultramafic minerals in the pit. Oscillatory strontium, barium, and zinc profiles may reflect changing water temperature, diet, or fish metabolism. Lead was detected in very low concentrations and may be related to anthropogenic influence. This closed lake system provides a unique opportunity to study an introduced exotic species in a setting where neither migration nor recruitment have been possible. The fish have successfully occupied the lake and continue to breed despite the influence of the surrounding rocks and local contamination. The chemical record retained within otoliths provides a method of monitoring trace elements affecting fish on a yearly basis and may be regarded as a useful assessment tool for examining the exposure of wild organisms to trace elements.

  1. Current status, between-year comparisons and maternal transfer of organohalogenated compounds (OHCs) in Arctic char (Salvelinus alpinus) from Bjørnøya, Svalbard (Norway)

    Energy Technology Data Exchange (ETDEWEB)

    Bytingsvik, J., E-mail: [Akvaplan-niva AS, The Fram Centre, N-9296 Tromsø Norway (Norway); Frantzen, M. [Akvaplan-niva AS, The Fram Centre, N-9296 Tromsø Norway (Norway); Götsch, A.; Heimstad, E.S. [NILU (Norwegian Institute for Air Research), The Fram Centre, N-9296 Tromsø Norway (Norway); Christensen, G. [Akvaplan-niva AS, The Fram Centre, N-9296 Tromsø Norway (Norway); Evenset, A. [Akvaplan-niva AS, The Fram Centre, N-9296 Tromsø Norway (Norway); University of Tromsø, The Arctic University of Norway, Pb 6050 Langnes, N-9037 Tromsø (Norway)


    High levels of organohalogenated compounds (OHCs) have been found in Arctic char from Lake Ellasjøen at Bjørnøya (Svalbard, Norway) compared to char from other arctic lakes. The first aim of the study was to investigate the OHC status, contaminant profile, and partitioning of OHCs between muscle and ovary tissue in spawning female char from the high-polluted Lake Ellasjøen and the low-polluted Lake Laksvatn. The second aim was to investigate if OHC levels in muscle tissue have changed over time. Between-lake comparisons show that the muscle levels (lipid weight) of hexachlorobenzene (HCB), chlordanes (∑ CHLs), mirex, dichlorodiphenyltrichloroethanes (∑ DDTs) and polychlorinated biphenyls (∑ PCBs) were up to 36 times higher in char from Ellasjøen than in Laksvatn, and confirm that the char from Ellasjøen are still heavily exposed compared to char from neighboring lake. A higher proportion of persistent OHCs were found in Ellasjøen compared to Laksvatn, while the proportion of the less persistent OHCs was highest in Laksvatn. A between-year comparison of OHC levels (i.e., HCB, DDTs, PCBs) in female and male char shows higher levels of HCB in female char from Ellasjøen in 2009/2012 compared to in 1999/2001. No other between-year differences in OHC levels were found. Due to small study groups, findings associated with between-year differences in OHC levels should be interpreted with caution. OHCs accumulate in the lipid rich ovaries of spawning females, resulting in up to six times higher levels of OHCs in ovaries compared to in muscle (wet weight). The toxic equivalent (TEQ)-value for the dioxin-like PCBs (PCB-105 and -118) in ovaries of the Ellasjøen char exceeded levels associated with increased egg mortality in rainbow trout (Oncorhynchus mykiss). Hence, we suggest that future studies should focus on the reproductive health and performance abilities of the high-exposed population of char inhabiting Lake Ellasjøen. - Highlights: • Examine levels, profile, time-trends and maternal transfer of OHCs in Arctic char • Char from Lake Ellasjøen (Bjørnøya, Norway) are known to be highly contaminated. • PCB-levels (2012): 36 times higher in char from Ellasjøen than in Laksvatn (ref.) • Higher HCB levels in female char from Ellasjøen in 2009/2012 than in 1999/2001 • OHC-levels were up to six times higher in ovaries than in muscle tissue.

  2. Lake bathymetry and species occurrence predict the distribution of a lacustrine apex predator. (United States)

    Hughes, M R; Dodd, J A; Maitland, P S; Adams, C E


    This study examined the abiotic and biotic characteristics of ecosystems that allow expression of a life history called ferox trout, the colloquial name given to brown trout Salmo trutta adopting a piscivorous life history strategy, an apex predator in post-glacial lakes in northern Europe. One hundred and ninety-two lakes in Scotland show evidence of currently, or historically, supporting ferox S. trutta; their presence was predicted in logistic models by larger and deeper lakes with a large catchment that also support populations of Arctic charr Salvelinus alpinus.

  3. Induction and viability of tetraploids in brook trout (Salvelinus fontinalis) (United States)

    Brook trout (Salvelinus fontinalis) populations are threatened by introduction of invasive species, habitat loss, and habitat degradation in their native range; and are a problem invasive species in western Unites States and Canada, and in Europe. Stocking sterile triploids has been promoted as an ...

  4. A new feeding group within larval Drusinae (Trichoptera: Limnephilidae): the alpinus-group sensu Schmid, 1956, including larval descriptions of Drusus franzi Schmid, 1956 and Drusus alpinus (Meyer-Dür, 1875) (United States)



    This paper presents a description of the hitherto unknown larvae of Drusus franzi Schmid 1956, and Drusus alpinus (Meyer-Dür 1875). Information on the morphological and genetic identification of both species is given, and the most important diagnostic features are illustrated. Their systematic position within the genus Drusus is affirmed and zoogeographical and ecological notes are added. PMID:27069350

  5. Same barcode, different biology: differential patterns of infectivity, specificity and pathogenicity in two almost identical parasite strains. (United States)

    Ramírez, Raúl; Bakke, Tor A; Harris, Philip D


    Two Norwegian isolates of the monogenean Gyrodactylus salaris Malmberg, 1957 with identical cytochrome c oxidase subunit I barcodes from different hosts, show highly divergent biological and behavioural characteristics. The Lierelva parasite strain, typically infecting Atlantic salmon, Salmo salar L., grew exponentially on Atlantic salmon, but the Pålsbufjorden parasite strain, commonly infecting Arctic charr, Salvelinus alpinus L., grew slowly on both hosts and was non-pathogenic to Atlantic salmon. Both parasite strains reproduced successfully on Arctic charr, but the Atlantic salmon-infecting Lierelva strain grew faster on both hosts. Experiments with isolated worms revealed differences in reproductive rates which may account for the observed population differences. Atlantic salmon parasites consistently gave birth at an earlier age than the Arctic charr parasites, with the differential increasing from 1 day for the first birth up to 2-4 days for the third birth. Arctic charr-infecting parasites were more active on Atlantic salmon than salmon parasites on Arctic charr, a behavioural strategy leading to enhanced G. salaris mortality. Sequencing of 10 kb of nuclear genomic markers revealed only four single nucleotide polymorphisms, confirming that isolates of G. salaris with differences in fitness traits influencing establishment, fecundity and behaviour may be remarkably similar at a molecular level. The framework for reporting and control of G. salaris requires re-appraisal in light of the discovery of variants with such divergent biology.

  6. Short-and long term niche segregation and individual specialization of brown trout (Salmo trutta) in species poor Faroese lakes

    DEFF Research Database (Denmark)

    Brodersen, Jakob; Malmquist, Hilmar J.; Landkildehus, Frank


    by comparing relative abundance, stable isotope ratios and diet in multiple habitats. In the presence of three-spined sticklebacks (Gasterosteus aculeatus), a higher proportion of the trout population was found in the pelagic habitat, and trout in general relied on a more pelagic diet base as compared to trout...... living in allopatry or in sympatry with Arctic charr (Salvelinus alpinus). Diet analyses revealed, however, that niche-segregation may be more complex than described on a one-dimensional pelagic-littoral axis. Trout from both littoral and offshore benthic habitats had in the presence of sticklebacks...... a less benthic diet as compared to trout living in allopatry or in sympatry with charr. Furthermore, we found individual habitat specialization between littoral/benthic and pelagic trout in deep lakes. Hence, our findings indicate that for trout populations interspecific competition can drive shifts...

  7. [Genetic Connectivity Between Sympatric Populations of Closely Related Char Species, Dolly Varden Salvelinus malma and White Char Salvelinus albus]. (United States)

    Salmenkova, E A


    The closely related chars Salvelinus malma and Salvelinus albus, which sympatrically inhabit the Kamchatka River basin and Kronotsky Lake (Kamchatka), attract the attention of the researchers because of their debated origin and taxonomic status. Previous studies of sympatric populations of these chars revealed small but statistically significant genetic differences between these species at a number of molecular markers, suggesting the presence of the genetic exchange and hybridization. In this study, based on genotypic characterization of nine microsatellite loci, a considerable level of historical and contemporary genetic migration between sympatric populations of these chars was demonstrated. At the individual level a high degree of hybridization was observed, mainly among the Dolly Varden individuals from the studied populations. The obtained evidence on the genetic connectivity between sympatric S. malma and S. albus do not support the separate species status of S. albus.

  8. Complete mitochondrial genomes of the Northern (Salvelinus malma) and Southern (Salvelinus curilus) Dolly Varden chars (Salmoniformes, Salmonidae). (United States)

    Balakirev, Evgeniy S; Romanov, Nikolai S; Ayala, Francisco J


    The complete mitochondrial genomes were sequenced from the Northern and Southern Dolly Varden chars, Salvelinus malma and S. curilus. The genome sequences are 16,654 bp in size in both species, and the gene arrangement, composition, and size are very similar to the salmonid fish genomes published previously. The level of sequence divergence between S. malma and S. curilus inferred from the complete mitochondrial genomes is relatively low (1.88%) indicating recent divergence of the species and/or historical hybridization.

  9. Food habits of dhole Cuon alpinus in Kalakad-Mundanthurai Tiger Reserve in Tamil Nadu, India

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    K. Muthamizh Selvan


    Full Text Available Food habits of dhole Cuon alpinus studied in Kalakad-Mundanthurai Tiger Reserve from January 2010 to July 2010 by analyzing 78 scats. Ten prey species were consumed by dholes in which Sambar was consumed highest percentage (30.77% followed by wild pig (23.08% and lowest was Jungle fowl (0.063%. In terms of biomass contribution sambar was highest (78.70% while jungle fowl was lowest contribution (3.85%. The total prey biomass consumed by dhole was 191.72 kg during our study period. This study will give basic information on food habits of dhole and also gives basic idea for better management strategies to protect this elegant carnivore.

  10. [Genetic divergence of mitochondrial DNA in white char Salvelinus albus and northern Dolly Varden char Salvelinus malma malma]. (United States)

    Oleĭnik, A G; Skurikhina, L A; Brykov, Vl A


    Comparative analysis of mitochondrial DNA variation was performed in white char Salvelinus albus and in its putative ancestor species, northern Dolly Varden char Salvelinus malma malma. Highly statistically significant differentiation of S. albus and S. m. malma in the areas of sympatric (Kamchatka River basin) and allopatric (Kronotskoe Lake and Kronotskaya River) residence was demonstrated. The mtDNA divergence between S. albus and S. m. malma did not exceed the range ofintraspecific variation in the populations of northern Dolly Varden char. At the same time, clusterization pattern of the Salvelinus chars provides hypothesis on the common origin of two allopatric populations of white char. Genealogical analysis of haplotypes indicates that S. albus and S. m. malma currently demonstrate incomplete radiation of mitochondrial lineages. The low nucleotide divergence estimates between S. albus and S. m. malma reflect the short time period since the beginning of the radiation of ancestral lineages. These estimates are determined by ancestral polymorphism and haplotype exchange between the diverged phylogenetic groups as a result of introgressive hybridization.

  11. Where have all the females gone? Male biased sex-ratio in Arctodiaptomus alpinus (Imhof, 1885) in alpine lakes (United States)

    Žibrat, U.; Brancelj, A.


    In populations with both males and females sex-ratio is one of the driving forces of population dynamics. It influences fecundity, inbreeding and social interactions. Sex-ratio is affected by several biotic and abiotic factors, either by selective killing of one sex or by inducing migrations. In alpine lakes of Triglav National Park, Slovenia, an extremely male biased sex-ratio in Arctodiaptomus alpinus (Imhof, 1885) was regularly observed since 1992. We analysed population dynamics and sex-ratio of A. alpinus in three alpine lakes (Jezero v Ledvicah, Rjavo jezero and Zgornje Kriško jezero) from Triglav National Park in Slovenia. In addition to seasonal dynamics we also researched long-term changes in sex-ratio (in a period of 11 years from autumn samples) as a result of increased air-temperature, and zooplankton diurnal vertical migrations. Adults of both sexes were found to appear at the same time in the water collumn with males prevailing throughout the season. A similar trend was found in copepodites CV. The percent of adult females began increasing in late summer, when there were no more copepodites and recrutation from copepodites CV to adults stopped, while male mortality increased. All cohorts of A. alpinus were found to perform diurnal vertical migrations. Both adult and CV females remained close to the bottom during the day and migrated vertically during the night. Results of the long-term study show no changes in sex-ratio in autumn.

  12. Seasonal Variations in the Use of Profundal Habitat among Freshwater Fishes in Lake Norsjø, Southern Norway, and Subsequent Effects on Fish Mercury Concentrations

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    Tom Robin Olk


    Full Text Available This study is based on monthly sampling of fish from grates mounted at an industrial water intake, located at a depth of 50 m in Lake Norsjø (Southern Norway during the year 2014, to investigate seasonal variations in the use of the profundal habitat and subsequent variations in total Hg-concentrations in profundal fish. Data on various fish present in a cold and dark hypolimnion of a large, deep, dimictic lake within the upper temperate zone of the Northern Hemisphere are rare. While predominant species such as A. charr (Salvelinus alpinus and E. smelt (Osmerus eperlanus were continuously present in this habitat, whitefish (Coregonus lavaretus occupied this habitat primarily during wintertime, while other common species like brown trout (Salmo trutta, perch (Perca fluviatilis and northern pike (Esox lucius were almost absent. Besides stomach analyses (diet and biometry, stable isotope analyses (δ15N and δ13C and total mercury (Tot-Hg analyses were carried out on the caught fish. The δ13C signature and stomach analyses revealed a combined profundal-pelagic diet for all three species, A. charr with the most profundal-based diet. Length was the strongest predictor for Hg in whitefish and A. charr, while age was the strongest explanatory variable for Hg in E. smelt. A. charr was the only species exhibiting seasonal variation in Hg, highest during winter and spring.

  13. Use of cover habitat by bull trout Salvelinus confluentus and lake trout Salvelinus namaycush in a laboratory environment (United States)

    Meeuwig, Michael H.; Guy, Christopher S.; Fredenberg, Wade A.


    Lacustrine-adfluvial bull trout, Salvelinus confluentus, migrate from spawning and rearing streams to lacustrine environments as early as age 0. Within lacustrine environments, cover habitat pro- vides refuge from potential predators and is a resource that is competed for if limiting. Competitive inter- actions between bull trout and other species could result in bull trout being displaced from cover habitat, and bull trout may lack evolutionary adaptations to compete with introduced species, such as lake trout, Salvelinus namaycush. A laboratory experiment was performed to examine habitat use and interactions for cover by juvenile (i.e., bull trout and lake trout. Differences were observed between bull trout and lake trout in the proportion of time using cover (F1,22.6=20.08, Pbull trout using cover and bottom habitats more than lake trout. Habitat selection ratios indicated that bull trout avoided water column habitat in the presence of lake trout and that lake trout avoided bottom habitat. Intraspecific and interspecific agonistic interactions were infrequent, but approximately 10 times greater for intraspecific inter- actions between lake trout. Results from this study provide little evidence that juvenile bull trout and lake trout compete for cover, and that species-specific differences in habitat use and selection likely result in habitat partitioning between these species.

  14. Lake trout (Salvelinus namaycush) suppression for bull trout (Salvelinus confluentus) recovery in Flathead Lake, Montana, North America (United States)

    Hansen, Michael J.; Hansen, Barry S; Beauchamp, David A.


    Non-native lake trout Salvelinus namaycush displaced native bull trout Salvelinus confluentus in Flathead Lake, Montana, USA, after 1984, when Mysis diluviana became abundant following its introduction in upstream lakes in 1968–1976. We developed a simulation model to determine the fishing mortality rate on lake trout that would enable bull trout recovery. Model simulations indicated that suppression of adult lake trout by 75% from current abundance would reduce predation on bull trout by 90%. Current removals of lake trout through incentivized fishing contests has not been sufficient to suppress lake trout abundance estimated by mark-recapture or indexed by stratified-random gill netting. In contrast, size structure, body condition, mortality, and maturity are changing consistent with a density-dependent reduction in lake trout abundance. Population modeling indicated total fishing effort would need to increase 3-fold to reduce adult lake trout population density by 75%. We conclude that increased fishing effort would suppress lake trout population density and predation on juvenile bull trout, and thereby enable higher abundance of adult bull trout in Flathead Lake and its tributaries.

  15. Potential Sources of High Frequency and Biphonic Vocalization in the Dhole (Cuon alpinus.

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    Roland Frey

    Full Text Available Biphonation, i.e. two independent fundamental frequencies in a call spectrum, is a prominent feature of vocal activity in dog-like canids. Dog-like canids can produce a low (f0 and a high (g0 fundamental frequency simultaneously. In contrast, fox-like canids are only capable of producing the low fundamental frequency (f0. Using a comparative anatomical approach for revealing macroscopic structures potentially responsible for canid biphonation, we investigated the vocal anatomy for 4 (1 male, 3 female captive dholes (Cuon alpinus and for 2 (1 male, 1 female wild red fox (Vulpes vulpes. In addition, we analyzed the acoustic structure of vocalizations in the same dholes that served postmortem as specimens for the anatomical investigation. All study dholes produced both high-frequency and biphonic calls. The anatomical reconstructions revealed that the vocal morphologies of the dhole are very similar to those of the red fox. These results suggest that the high-frequency and biphonic calls in dog-like canids can be produced without specific anatomical adaptations of the sound-producing structures. We discuss possible production modes for the high-frequency and biphonic calls involving laryngeal and nasal structures.

  16. Developmental toxicity of selenium to Dolly Varden char (Salvelinus malma). (United States)

    McDonald, Blair G; deBruyn, Adrian M H; Elphick, James R F; Davies, Martin; Bustard, David; Chapman, Peter M


    Gametes were collected from Dolly Varden char (Salvelinus malma) from waterbodies in a region exposed to mining-related selenium (Se) releases in British Columbia, Canada. Fertilized eggs were incubated in a laboratory and deformities were assessed on newly-hatched alevins using a graduated severity index. No effects were observed on egg or alevin survival or larval weight across the studied exposure range of 5.4 to 66 mg/kg dry weight in egg. Length of some larvae was reduced at the highest egg Se concentrations and a clear residue-response relationship was observed for larval deformity. The egg concentration corresponding to a 10% increase in the frequency of deformity (EC10) was 54 mg/kg dry weight, which is substantially higher than reported for other cold-water fish species.

  17. Plecotus alpinus: primi dati sull'utilizzo dell'habitat

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    Adriano Martinoli


    Full Text Available Negli ultimi anni il numero delle specie di Chirotteri note per l?Europa si è accresciuto, grazie all?uso di tecniche di genetica molecolare, ed in particolare il genere Plecotus è quello che ha registrato maggiori cambiamenti con la descrizione di tre nuove specie: Plecotus kolombatovici, P. alpinus e P. sardus (Kiefer & Veith, 2001; Mucedda et al., 2002. Alla luce di queste nuove scoperte, la distribuzione geografica e le preferenze dell?habitat delle due specie ?storiche? di Orecchione in Europa, Plecotus auritus e P. austriacus, dovrebbero essere riviste: in questo contesto si inserisce l?indagine svolta nel Parco Regionale Campo dei Fiori (in provincia di Varese sulla prima colonia riproduttiva di Plecotus alpinus segnalata per la regione Lombardia. Al fine di valutare le preferenze nell?uso dell?habitat e le direttrici di spostamento preferenziali di tale specie, nonché per l?identificazione di siti di rilevanza per l?allevamento della prole, si è fatto ricorso a tecniche di radiolocalizzazione, subordinate alla cattura a vivo degli animali. Le catture si sono svolte nel periodo 15 giugno ? 15 agosto del 2002 e del 2003. Per ogni individuo catturato, oltre alla determinazione di specie, sesso e classe d?età, sono stati rilevati i dati biometrici e prelevati campioni di tessuto destinati all?analisi genetica. Sono state inoltre registrate le emissioni ultrasonore. Durante il primo anno di indagine sono state seguite mediante radiolocalizzazione 5 femmine adulte (4 allattanti ed una non allattante e due femmine subadulte, mentre durante il secondo anno sono state munite di radiocollare 6 femmine adulte (5 allattanti ed una non allattante ed una femmina subadulta. Ai pipistrelli è stato applicato un emettitore radio (tag modello LB-2, Holohil Systems Ltd, Ontario, Canada. Il segnale emesso è stato ricevuto in campo mediante l?utilizzo di radio (Wildlife

  18. Sprint swimming performance of wild bull trout (Salvelinus confluentus) (United States)

    Mesa, M.G.; Phelps, J.; Weiland, L.K.


    We conducted laboratory experiments to determine the sprint swimming performance of wild juvenile and adult bull trout Salvelinus confluentus. Sprint swimming speeds were estimated using high-speed digital video analysis. Thirty two bull trout were tested in sizes ranging from about 10 to 31 cm. Of these, 14 fish showed at least one motivated, vigorous sprint. When plotted as a function of time, velocity of fish increased rapidly with the relation linear or slightly curvilinear. Their maximum velocity, or Vmax, ranged from 1.3 to 2.3 m/s, was usually achieved within 0.8 to 1.0 s, and was independent of fish size. Distances covered during these sprints ranged from 1.4 to 2.4 m. Our estimates of the sprint swimming performance are the first reported for this species and may be useful for producing or modifying fish passage structures that allow safe and effective passage of fish without overly exhausting them. ?? 2008 by the Northwest Scientific Association. All rights reserved.

  19. Multiscale hydrogeomorphic influences on bull trout (Salvelinus confluentus) spawning habitat (United States)

    Bean, Jared R; Wilcox, Andrew C.; Woessner, William W.; Muhlfeld, Clint C.


    We investigated multiscale hydrogeomorphic influences on the distribution and abundance of bull trout (Salvelinus confluentus) spawning in snowmelt-dominated streams of the upper Flathead River basin, northwestern Montana. Within our study reaches, bull trout tended to spawn in the finest available gravel substrates. Analysis of the mobility of these substrates, based on one-dimensional hydraulic modeling and calculation of dimensionless shear stresses, indicated that bed materials in spawning reaches would be mobilized at moderate (i.e., 2-year recurrence interval) high-flow conditions, although the asynchronous timing of the fall–winter egg incubation period and typical late spring – early summer snowmelt high flows in our study area may limit susceptibility to redd scour under current hydrologic regimes. Redd occurrence also tended to be associated with concave-up bedforms (pool tailouts) with downwelling intragravel flows. Streambed temperatures tracked stream water diurnal temperature cycles to a depth of at least 25 cm, averaging 6.1–8.1 °C in different study reaches during the spawning period. Ground water provided thermal moderation of stream water for several high-density spawning reaches. Bull trout redds were more frequent in unconfined alluvial valley reaches (8.5 versus 5.0 redds·km−1 in confined valley reaches), which were strongly influenced by hyporheic and groundwater – stream water exchange. A considerable proportion of redds were patchily distributed in confined valley reaches, however, emphasizing the influence of local physical conditions in supporting bull trout spawning habitat. Moreover, narrowing or “bounding” of these alluvial valley segments did not appear to be important. Our results suggest that geomorphic, thermal, and hydrological factors influence bull trout spawning occurrence at multiple spatial scales.

  20. Effets du conditionnement en jours longs à la fin du cycle reproducteur sur la période d'ovulation et sur les sécrétions gonadotropes chez l'omble chevalier (Salvelinus alpinus

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    Full Text Available Les ombles chevaliers originaires du Léman se reproduisent à la fin de l'automne. En élevage, il est intéressant de retarder de quelques mois la période des ovulations car ce poisson a besoin d'une température inférieure à 6°C pendant l'ovulation. Il est plus facile de fournir une eau à cette température aux géniteurs retardés qui ovulent en hiver qu'à ceux qui ovulent naturellement en automne. Le conditionnement des ombles chevaliers en jours longs (17L-7N pendant l'automne permet de retarder de plusieurs mois la période des ovulations. Cette méthode a l'inconvénient de provoquer un étalement des ovulations sur plus de 3 mois. Le reconditionnement des géniteurs en jours courts en décembre supprime ce problème. L'efficacité du traitement en jours longs ne semble pas dépendre de la durée de son application pourvu que celle-ci dépasse 1,5 mois. Chez les femelles conditionnées en jours longs en automne et en hiver, les concentrations en gonadotropine plasmatique (GTH II sont très faibles. Le niveau de la GTH II plasmatique augmente trois semaines après un transfert en jours courts en janvier. Les concentrations de la GTH II plasmatique au cours de l'ovulation sont significativement plus faibles chez les femelles conditionnées en jours longs en janvier que chez les animaux reconditionnés en jours courts. A ce stade du cycle reproducteur, la GTH I plasmatique reste toujours à un niveau très faible, quel que soit le régime photopériodique. La pose d'implant de mélatonine chez les poissons ne modifie pas les sécrétions gonadotropes en jours longs comme en jours courts. La réceptivité hypophysaire des femelles à une stimulation de la sécrétion gonadotrope par une injection de GnRH n'est pas modifiée par le conditionnement des poissons en jours longs. Aucun effet du pimozide sur la sécrétion de la GTH II n'a pu être mis en évidence chez les géniteurs conditionnés en jours longs. Ces résultats permettent de supposer que l'action inhibitrice des jours longs sur l'ovulation n'est pas la conséquence d'un blocage de type dopaminergique de la sécrétion gonadotrope. Ce type d'inhibition mettrait en oeuvre des mécanismes différents de ceux impliqués dans le blocage de l'ovulation par des températures élevées. L'effet inhibiteur des jours longs à ce stade du cycle reproducteur passe par une diminution de la sécrétion gonadotrope de la GTH II, probablement en relation avec des modifications du contrôle hypothalamique de la sécrétion de la gonadotropine hypophysaire (GTH II.

  1. Endocrine disruption in brook trout (Salvelinus fontinalis) exposed to leachate from a public refuse dump

    NARCIS (Netherlands)

    Noaksson, E.; Linderoth, M.; Bosveld, A.T.C.; Norrgren, L.; Zebühr, Y.; Balk, L.


    Lake Molnbyggen was previously found to harbour a large number of sexually immature female perch (Perca fluviatilis) suffering from endocrine disruption. In an attempt to pin-point the source of the endocrine-disrupting substance(s) (EDSs), brook trout (Salvelinus fontinalis) from Vadbacken, a strea

  2. Effects of roads on bull trout (Salvelinus confluentus), a federally threatened species


    Teachout, Emily; Quan, Jennifer


    The bull trout (Salvelinus confluentus) is federally listed as threatened under the Endangered Species Act. Bull trout are apex predators requiring a large prey base and a large home range, and are known to move throughout and between basins in search of prey. However, bull trout are dependent upon very cold, clean waters for spawning (below 9 degrees Celsius) and are typically characterized as spawning in the upper-most reaches of watersheds. Bull trout have four life history forms: resident...

  3. Ribosomal genes and heat shock proteins as putative markers for chronic, sublethal heat stress in Arctic charr: applications for aquaculture and wild fish. (United States)

    Quinn, Nicole L; McGowan, Colin R; Cooper, Glenn A; Koop, Ben F; Davidson, William S


    Arctic charr thrive at high densities and can live in freshwater year round, making this species especially suitable for inland, closed containment aquaculture. However, it is a cold-water salmonid, which both limits where the species can be farmed and places wild populations at particular risk to climate change. Previously, we identified genes associated with tolerance and intolerance to acute, lethal temperature stress in Arctic charr. However, there remained a need to examine the genes involved in the stress response to more realistic temperatures that could be experienced during a summer heat wave in grow-out tanks that are not artificially cooled, or under natural conditions. Here, we exposed Arctic charr to sublethal heat stress of 15-18°C for 72 h, and gill tissues extracted before, during (i.e., at 72 h), immediately after cooling and after 72 h of recovery at ambient temperature (6°C) were used for gene expression profiling by microarray and qPCR analyses. The results revealed an expected pattern for heat shock protein expression, which was highest during heat exposure, with significantly reduced expression (approaching control levels) quickly thereafter. We also found that the expression of numerous ribosomal proteins was significantly elevated immediately and 72 h after cooling, suggesting that the gill tissues were undergoing ribosome biogenesis while recovering from damage caused by heat stress. We suggest that these are candidate gene targets for the future development of genetic markers for broodstock development or for monitoring temperature stress and recovery in wild or cultured conditions.

  4. Status specific tailoring of sperm behavior in an external fertilizer

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    Torvald Blikra Egeland


    Full Text Available Why dominant males experiencing intense sperm competition sometimes show low investments in sperm production is not always obvious. One well-documented example is that of the external fertilizing teleost, the Arctic charr (Salvelinus alpinus, where individuals becoming dominant reduce sperm production and sperm swimming speed in water compared to subordinates. Here we report how ovarian fluid differentially influences sperm velocity of dominant and subordinate male Arctic charr. That is, sperm from dominant males increase their velocity in water diluted ovarian fluid compared to that observed in water, while sperm from subordinates, on the other hand, decrease velocity in ovarian fluid compared to that observed in water. Thus, subordinates, who invest more resources in their sperm and usually show the highest sperm velocity in water, have lower gains from their investment than dominant males when sperm are swimming in ovarian fluid. In sum, our result suggests that ovarian fluid increase sperm velocity more in dominant males than in subordinate males. Although this finding could partly be caused by cryptic female choice exerted by the ovarian fluid for sperm from dominant males, an alternative and more parsimonious explanation is that sperm from dominant males may simply be better designed for swimming in ovarian fluid compared to sperm from subordinate males. Thus, sperm production in the two reproductive roles seems to be adaptively tailored to different external environments.

  5. EROD activity in gill filaments of anadromous and marine fish as a biomarker of dioxin-like pollutants. (United States)

    Jönsson, Maria; Abrahamson, Alexandra; Brunström, Björn; Brandt, Ingvar; Ingebrigtsen, Kristian; Jørgensen, Even H


    The applicability of a gill filament-based ethoxyresorufin O-deethylase (EROD) assay, originally developed in rainbow trout, was examined in Atlantic salmon (Salmo salar), Arctic charr (Salvelinus alpinus), Atlantic cod (Gadus morhua), saithe (Pollachius virens) and spotted wolffish (Anarhichas minor). All species but spotted wolffish showed strong EROD induction in tip pieces of gill filaments following 48 h of exposure to waterborne beta-naphthoflavone. Atlantic salmon parr, smolts held in freshwater and smolts transferred to seawater showed EROD induction of similar magnitude. Arctic charr, differing 11-fold in body weight, showed similar EROD activities as expressed per gill filament tip. Laboratory exposure of saithe to water and sediments collected at polluted sites, resulted in strong EROD induction. In conclusion, the gill filament assay seems useful for monitoring exposure to aryl hydrocarbon receptor agonists in various species. Furthermore, smoltification status, water salinity and body size proved to have minor influence on gill filament EROD activity. However, the results in spotted wolffish show that some species may be less suitable for monitoring using the gill assay. Assessment of gill filament EROD activity in fish exposed to polluted water and sediments in the laboratory proved to be an easy and cost-effective way to survey pollution with dioxin-like chemicals.

  6. Concomitant Antibiotic and Mercury Resistance Among Gastrointestinal Microflora of Feral Brook Trout, Salvelinus fontinalis (United States)

    Meredith, Matthew M.; Parry, Erin M.; Guay, Justin A.; Markham, Nicholas O.; Danner, G. Russell; Johnson, Keith A.; Barkay, Tamar; Fekete, Frank A.


    Twenty-nine bacterial isolates representing eight genera from the gastrointestinal tracts of feral brook trout Salvelinus fontinalis (Mitchell) demonstrated multiple maximal antibiotic resistances and concomitant broad-spectrum mercury (Hg) resistance. Equivalent viable plate counts on tryptic soy agar supplemented with either 0 or 25 μM HgCl2 verified the ubiquity of mercury resistance in this microbial environment. Mercury levels in lake water samples measured 1.5 ng L−1; mercury concentrations in fish filets ranged from 81.8 to 1,080 ng g−1 and correlated with fish length. The presence of similar antibiotic and Hg resistance patterns in multiple genera of gastrointestinal microflora supports a growing body of research that multiple selective genes can be transferred horizontally in the presence of an unrelated individual selective pressure. We present data that bioaccumulation of non-point source Hg pollution could be a selective pressure to accumulate both antibiotic and Hg resistant bacteria. PMID:22850694

  7. Bioenergetic evaluation of diel vertical migration by bull trout (Salvelinus confluentus) in a thermally stratified reservoir (United States)

    Eckmann, Madeleine; Dunham, Jason; Connor, Edward J.; Welch, Carmen A.


    Many species living in deeper lentic ecosystems exhibit daily movements that cycle through the water column, generally referred to as diel vertical migration (DVM). In this study, we applied bioenergetics modelling to evaluate growth as a hypothesis to explain DVM by bull trout (Salvelinus confluentus) in a thermally stratified reservoir (Ross Lake, WA, USA) during the peak of thermal stratification in July and August. Bioenergetics model parameters were derived from observed vertical distributions of temperature, prey and bull trout. Field sampling confirmed that bull trout prey almost exclusively on recently introduced redside shiner (Richardsonius balteatus). Model predictions revealed that deeper (>25 m) DVMs commonly exhibited by bull trout during peak thermal stratification cannot be explained by maximising growth. Survival, another common explanation for DVM, may have influenced bull trout depth use, but observations suggest there may be additional drivers of DVM. We propose these deeper summertime excursions may be partly explained by an alternative hypothesis: the importance of colder water for gametogenesis. In Ross Lake, reliance of bull trout on warm water prey (redside shiner) for consumption and growth poses a potential trade-off with the need for colder water for gametogenesis.

  8. Allantoinase in lake trout (Salvelinus namaycush): in vitro effects of PCBs, DDT and metals (United States)

    Passino, Dora R. May; Cotant, Carol A.


    1. Allantoinase, an enzyme in the purine-urea cycle, was found in livers of Salvelinus namaycush (Osteichthyes: Salmoniformes). 2. The enzyme was active from pH 6.6 to 8.2 at 37°C and from pH 7.4 to 9.0 at 10°C and had an Arrhenius energy of activation of 11.0 kcal/mol and a temperature quotient of 2.0. The Km of the enzyme homogenate was 8.4 mM allantoin. 3. The concentration of inorganic metals at which 50% inhibition occurred during in vitro exposure were 6.0 mg/l Cu2+, 6.7 mg/l Cd2+, 34 mg/l Hg2+ and 52 mg/l Pb2+. The in vitro sensitivity to PCBs, DDT and DDE and kinetics in the presence of metals were determined. 4. Allantoinase activity was negatively correlated with body length for fish from Lake Michigan but not from Lake Superior or the laboratory.

  9. Sexual difference in mercury concentrations of lake trout (Salvelinus namaycush) from Lake Ontario (United States)

    Madenjian, C.P.; Keir, M.J.; Whittle, D.M.


    We determined total mercury (Hg) concentrations in 50 female lake trout (Salvelinus namaycush) and 69 male lake trout from Lake Ontario (Ontario, Canada and New York, United States). Results showed that, on average, males were 8% higher in Hg concentration than females in Lake Ontario. We also used bioenergetics modeling to determine whether a sexual difference in gross growth efficiency (GGE) could explain the observed sexual difference in Hg concentrations. According to the bioenergetics modeling results, male GGE was about 3% higher than female GGE, on average. Although the bioenergetics modeling could not explain the higher Hg concentrations exhibited by the males, a sexual difference in GGE remained a plausible explanation for the sexual difference in Hg concentrations of the lake trout. In an earlier study, male lake trout from Lake Ontario were found to be 22% higher in polychlorinated biphenyl (PCB) concentration than females from Lake Ontario. Thus, although males were higher in both Hg and PCB concentrations, the degree of the sexual difference in concentration varied between the two contaminants. Further research on sexual differences in Hg excretion rates and Hg direct uptake rates may be needed to resolve the disparity in results between the two contaminants.

  10. Spawning site fidelity of wild and hatchery lake trout (Salvelinus namaycush) in northern Lake Huron (United States)

    Binder, Thomas; Riley, Stephen C.; Holbrook, Christopher; Hansen, Michael J.; Bergstedt, Roger A.; Bronte, Charles R.; He, Ji; Krueger, Charles C.


    Fidelity to high-quality spawning sites helps ensure that adults repeatedly spawn at sites that maximize reproductive success. Fidelity is also an important behavioural characteristic to consider when hatchery-reared individuals are stocked for species restoration, because artificial rearing environments may interfere with cues that guide appropriate spawning site selection. Acoustic telemetry was used in conjunction with Cormack–Jolly–Seber capture–recapture models to compare degree of spawning site fidelity of wild and hatchery-reared lake trout (Salvelinus namaycush) in northern Lake Huron. Annual survival was estimated to be between 77% and 81% and did not differ among wild and hatchery males and females. Site fidelity estimates were high in both wild and hatchery-reared lake trout (ranging from 0.78 to 0.94, depending on group and time filter), but were slightly lower in hatchery-reared fish than in wild fish. The ecological implication of the small difference in site fidelity between wild and hatchery-reared lake trout is unclear, but similarities in estimates suggest that many hatchery-reared fish use similar spawning sites to wild fish and that most return to those sites annually for spawning.

  11. [Population genetic structure of northern Dolly Varden char Salvelinus malma malma in Asia and North America]. (United States)

    Oleĭnik, A G; Skurikhina, L A; Brykov, Vl A


    The level of genetic differentiation of northern Dolly Varden char Salvelinus malma malma from Asia and North America was evaluated using the data on mtDNA variation (regions ND1/ND2, ND5/ND6, and Cytb/D loop) obtained by means of PCR-RFLP analysis. For S. m. malma, the mean values of haplotype and nucleotide diversity were 0.5261 +/- 0.00388 and 0.001558, respectively. The mean estimate of the population nucleotide divergence constituted 0.055%. It was demonstrated that S. m. malma on the most part of the species range examined (drainages of the Beaufort Sea, Chukotka Sea, Bering Sea, and the Sea of Okhotsk) was characterized by the population genetic structure with the low level of genetic differentiation and divergence. At the same time, populations from the Pacific Ocean Gulf of Alaska demonstrated marked genetic differentiation, supported by the high pairwise phi(ST) values (from 0.4198 to 0.5211) and nucleotide divergence estimates (mean divergence, 0.129%), from Asian and North American populations. Nested analysis of molecular variance (AMOVA) showed that most of the mtDNA variation in S. m. malma fell in the intrapopulation component (72.5%). At the same time, the differences between the populations (21.1%) and between the regions (6.4%) made lower contribution to the total variation.

  12. Understanding environmental DNA detection probabilities: A case study using a stream-dwelling char Salvelinus fontinalis (United States)

    Wilcox, Taylor M; Mckelvey, Kevin S.; Young, Michael K.; Sepulveda, Adam; Shepard, Bradley B.; Jane, Stephen F; Whiteley, Andrew R.; Lowe, Winsor H.; Schwartz, Michael K.


    Environmental DNA sampling (eDNA) has emerged as a powerful tool for detecting aquatic animals. Previous research suggests that eDNA methods are substantially more sensitive than traditional sampling. However, the factors influencing eDNA detection and the resulting sampling costs are still not well understood. Here we use multiple experiments to derive independent estimates of eDNA production rates and downstream persistence from brook trout (Salvelinus fontinalis) in streams. We use these estimates to parameterize models comparing the false negative detection rates of eDNA sampling and traditional backpack electrofishing. We find that using the protocols in this study eDNA had reasonable detection probabilities at extremely low animal densities (e.g., probability of detection 0.18 at densities of one fish per stream kilometer) and very high detection probabilities at population-level densities (e.g., probability of detection > 0.99 at densities of ≥ 3 fish per 100 m). This is substantially more sensitive than traditional electrofishing for determining the presence of brook trout and may translate into important cost savings when animals are rare. Our findings are consistent with a growing body of literature showing that eDNA sampling is a powerful tool for the detection of aquatic species, particularly those that are rare and difficult to sample using traditional methods.

  13. Hiding in Plain Sight: A Case for Cryptic Metapopulations in Brook Trout (Salvelinus fontinalis.

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    David C Kazyak

    Full Text Available A fundamental issue in the management and conservation of biodiversity is how to define a population. Spatially contiguous fish occupying a stream network have often been considered to represent a single, homogenous population. However, they may also represent multiple discrete populations, a single population with genetic isolation-by-distance, or a metapopulation. We used microsatellite DNA and a large-scale mark-recapture study to assess population structure in a spatially contiguous sample of Brook Trout (Salvelinus fontinalis, a species of conservation concern. We found evidence for limited genetic exchange across small spatial scales and in the absence of barriers to physical movement. Mark-recapture and stationary passive integrated transponder antenna records demonstrated that fish from two tributaries very seldom moved into the opposite tributary, but movements between the tributaries and mainstem were more common. Using Bayesian genetic clustering, we identified two genetic groups that exhibited significantly different growth rates over three years of study, yet survival rates were very similar. Our study highlights the importance of considering the possibility of multiple genetically distinct populations occurring within spatially contiguous habitats, and suggests the existence of a cryptic metapopulation: a spatially continuous distribution of organisms exhibiting metapopulation-like behaviors.

  14. Sexual difference in PCB concentrations of lake trout (Salvelinus namaycush) from Lake Ontario (United States)

    Madenjian, Charles P.; Keir, Michael J.; Whittle, D. Michael; Noguchi, George E.


    We determined polychlorinated biphenyl (PCB) concentrations in 61 female lake trout (Salvelinus namaycush) and 71 male lake trout from Lake Ontario (Ontario, Canada and New York, United States). To estimate the expected change in PCB concentration due to spawning, PCB concentrations in gonads and in somatic tissue of lake trout were also determined. In addition, bioenergetics modeling was applied to investigate whether gross growth efficiency (GGE) differed between the sexes. Results showed that, on average, males were 22% higher in PCB concentration than females in Lake Ontario. Results from the PCB determinations of the gonads and somatic tissues revealed that shedding of the gametes led to 3% and 14% increases in PCB concentration for males and females, respectively. Therefore, shedding of the gametes could not explain the higher PCB concentration in male lake trout. According to the bioenergetics modeling results, GGE of males was about 2% higher than adult female GGE, on average. Thus, bioenergetics modeling could not explain the higher PCB concentrations exhibited by the males. Nevertheless, a sexual difference in GGE remained a plausible explanation for the sexual difference in PCB concentrations of the lake trout.

  15. Net trophic transfer efficiencies of polychlorinated biphenyl congeners to lake trout (Salvelinus namaycush) from its prey (United States)

    Madenjian, Charles P.; David, Solomon R.; Rediske, Richard R.; O’Keefe, James P.


    Lake trout (Salvelinus namaycush) were fed bloater (Coregonus hoyi) in eight laboratory tanks over a 135-d experiment. At the start of the experiment, four to nine fish in each tank were sacrificed, and the concentrations of 75 polychlorinated biphenyl (PCB) congeners within these fish were determined. Polychlorinated biphenyl congener concentrations were also determined in the 10 lake trout remaining in each of the eight tanks at the end of the experiment as well as in the bloater fed to the lake trout. Each lake trout was weighed at the start and the end of the experiment, and the amount of food eaten by the lake trout was recorded. Using these measurements, net trophic transfer efficiency (γ) from the bloater to the lake trout in each of the eight tanks was calculated for each of the 75 congeners. Results showed that γ did not vary significantly with the degree of chlorination of the PCB congeners, and γ averaged 0.66 across all congeners. However,γ did show a slight, but significant, decrease as logKOW increased from 6.0 to 8.2. Activity level of the lake trout did not have a significant effect on γ.

  16. Genetic and phenotypic variation along an ecological gradient in lake trout Salvelinus namaycush (United States)

    Baillie, Shauna M.; Muir, Andrew M.; Hansen, Michael J.; Krueger, Charles C.; Bentzen, Paul


    BackgroundAdaptive radiation involving a colonizing phenotype that rapidly evolves into at least one other ecological variant, or ecotype, has been observed in a variety of freshwater fishes in post-glacial environments. However, few studies consider how phenotypic traits vary with regard to neutral genetic partitioning along ecological gradients. Here, we present the first detailed investigation of lake trout Salvelinus namaycushthat considers variation as a cline rather than discriminatory among ecotypes. Genetic and phenotypic traits organized along common ecological gradients of water depth and geographic distance provide important insights into diversification processes in a lake with high levels of human disturbance from over-fishing.ResultsFour putative lake trout ecotypes could not be distinguished using population genetic methods, despite morphological differences. Neutral genetic partitioning in lake trout was stronger along a gradient of water depth, than by locality or ecotype. Contemporary genetic migration patterns were consistent with isolation-by-depth. Historical gene flow patterns indicated colonization from shallow to deep water. Comparison of phenotypic (Pst) and neutral genetic variation (Fst) revealed that morphological traits related to swimming performance (e.g., buoyancy, pelvic fin length) departed more strongly from neutral expectations along a depth gradient than craniofacial feeding traits. Elevated phenotypic variance with increasing water depth in pelvic fin length indicated possible ongoing character release and diversification. Finally, differences in early growth rate and asymptotic fish length across depth strata may be associated with limiting factors attributable to cold deep-water environments.ConclusionWe provide evidence of reductions in gene flow and divergent natural selection associated with water depth in Lake Superior. Such information is relevant for documenting intraspecific biodiversity in the largest freshwater lake

  17. [Allozyme diversity and genetic divergence of the dolly varden Salvelinus malma Walbaum from the Kuril islands]. (United States)

    Omel'chenko, V T; Salmenkova, E A; Shed'ko, S V


    Genetic variation was studied in the southern subspecies of the Asian Dolly Varden Salvelinus malma krascheninnikovi from the Kuril Islands. Thirty-six genetic loci controlling 19 enzyme systems were analyzed in 13 Dolly Varden populations from the Shumshu, Paramushir, Onekotan, Rasshua, Simushir, Urup, Iturup, and Kunashir islands. In the studied populations, the proportion of polymorphic loci was 35 to 85% and the mean heterozygosity was 0.104 to 0.173; populations from the Kunashir Island were characterized by maximum heterozygosity. In the island populations examined, significant inter-population heterogeneity of allele frequencies was found for all studied population pairs. For the total population of all islands, the inter-population diversity (GST = 0.188) was comparable to this parameter for the total population from the Kunashir Island (GST = 0.170). Genetic distances between populations did not correlate with the corresponding geographical distances, which indicates the lack of a pronounced gene exchange between the island populations. Cluster analysis and multidimensional scaling based on genetic distances did not reveal clear groups among the studied populations but indicated greater similarity within the Iturup-Simushir-Urup-Paramushir group and a greater genetic divergence of the Kunashir, Onekotan, Rasshua, and especially Shumshu populations. In the Shumshu population, allele frequencies indicate the admixture of genes of the northern Dolly Varden. The observed pattern of genetic differentiation was probably caused largely by genetic drift under the conditions of a limited gene flow because of homing (which is typical of the Dolly Varden) and the presence of isolated nonanadromous populations. The population-genetic analysis of the Dolly Varden from the Kuril Islands does not give grounds to distinguish any other isolated Dolly Varden species in this region than S. malma, which is represented by the southern form S. m. krascheninnikovi with an

  18. First report on the bacterial diversity in the distal gut of dholes (Cuon alpinus) by using 16S rRNA gene sequences analysis. (United States)

    Chen, Lei; Zhang, Honghai; Liu, Guangshuai; Sha, Weilai


    The aim of this study was to investigate the bacterial community in the distal gut of dholes (Cuon alpinus) based on the analysis of bacterial 16S rRNA gene sequences. Fecal samples were collected from five healthy unrelated dholes captured from Qilian Mountain in Gansu province of China. The diversity of the fecal bacteria community was investigated by constructing a polymerase chain reaction (PCR)-amplified 16S rRNA gene clone library. Bacterial 16S rRNA gene was amplified by using universal bacterial primers 27F and 1492R. A total of 275 chimera-free near full length 16S rRNA gene sequences were collected, and 78 non-redundant bacteria phylotypes (operational taxonomical units, OTUs) were identified according to the 97 % sequence similarity. Forty-two OTUs (53.8 %) showed less than 98 % sequence similarity to 16S rRNA gene sequences reported previously. Phylogenetic analysis demonstrated that dhole bacterial community comprised five different phyla, with the majority of sequences being classified within the phylum Bacteroidetes (64.7 %), followed by Firmicutes (29.8 %), Fusobacteria (4.7 %),Proteobacteria (0.4 %), and Actinobacteria (0.4 %). The only order Bacteroidales in phylum Bacteroidetes was the most abundant bacterial group in the intestinal bacterial community of dholes. Firmicutes and Bacteroidetes were the two most diverse bacterial phyla with 46.2 and 44.9 % of OTUs contained, respectively. Bacteroidales and Clostridiales were the two most diverse bacterial orders that contained 44.9 and 39.7 % of OTUs, respectively.

  19. [The divergence of the dolly varden char Salvelinus malma in Asian Northern Pacific populations inferred from the PCR-RFLP analysis of the mitochondrial DNA]. (United States)

    Oleĭnik, A G; Skurikhina, L A; Brykov, V A


    Genetic differentiation of the dolly varden char Salvelinus malma Walbaum was studied in five populations from the western part of the Northern Pacific. Using restriction analysis (RFLP), we examined polymorphism of three mitochondrial DNA (mtDNA) fragments amplified in polymerase chain reaction (PCR). MtDNA haplotypes were shown to fall into two phylogenetic groups, which probably reflect the existence of two previously described subspecies of Asian dolly varden, S. malma malma and S. malma krascheninnikovi. The divergence of mtDNA nucleotide sequences in the dolly varden subspecies (about 4%) corresponds to the differences between the valid char species from the genus Salvelinus.

  20. Evaluating the growth potential of sea lampreys (Petromyzon marinus) feeding on siscowet lake trout (Salvelinus namaycush) in Lake Superior (United States)

    Moody, E.K.; Weidel, B.C.; Ahrenstorff, T.D.; Mattes, W.P.; Kitchell, J.F.


    Differences in the preferred thermal habitat of Lake Superior lake trout morphotypes create alternative growth scenarios for parasitic sea lamprey (Petromyzon marinus) attached to lake trout hosts. Siscowet lake trout (Salvelinus namaycush) inhabit deep, consistently cold water (4–6 °C) and are more abundant than lean lake trout (Salvelinus namaycush) which occupy temperatures between 8 and 12 °C during summer thermal stratification. Using bioenergetics models we contrasted the growth potential of sea lampreys attached to siscowet and lean lake trout to determine how host temperature influences the growth and ultimate size of adult sea lamprey. Sea lampreys simulated under the thermal regime of siscowets are capable of reaching sizes within the range of adult sea lamprey sizes observed in Lake Superior tributaries. High lamprey wounding rates on siscowets suggest siscowets are important lamprey hosts. In addition, siscowets have higher survival rates from lamprey attacks than those observed for lean lake trout which raises the prospect that siscowets serve as a buffer to predation on more commercially desirable hosts such as lean lake trout, and could serve to subsidize lamprey growth.

  1. Chromosomal characteristics and distribution of rDNA sequences in the brook trout Salvelinus fontinalis (Mitchill, 1814). (United States)

    Śliwińska-Jewsiewicka, A; Kuciński, M; Kirtiklis, L; Dobosz, S; Ocalewicz, K; Jankun, Malgorzata


    Brook trout Salvelinus fontinalis (Mitchill, 1814) chromosomes have been analyzed using conventional and molecular cytogenetic techniques enabling characteristics and chromosomal location of heterochromatin, nucleolus organizer regions (NORs), ribosomal RNA-encoding genes and telomeric DNA sequences. The C-banding and chromosome digestion with the restriction endonucleases demonstrated distribution and heterogeneity of the heterochromatin in the brook trout genome. DNA sequences of the ribosomal RNA genes, namely the nucleolus-forming 28S (major) and non-nucleolus-forming 5S (minor) rDNAs, were physically mapped using fluorescence in situ hybridization (FISH) and primed in situ labelling. The minor rDNA locus was located on the subtelo-acrocentric chromosome pair No. 9, whereas the major rDNA loci were dispersed on 14 chromosome pairs, showing a considerable inter-individual variation in the number and location. The major and minor rDNA loci were located at different chromosomes. Multichromosomal location (3-6 sites) of the NORs was demonstrated by silver nitrate (AgNO3) impregnation. All Ag-positive i.e. active NORs corresponded to the GC-rich blocks of heterochromatin. FISH with telomeric probe showed the presence of the interstitial telomeric site (ITS) adjacent to the NOR/28S rDNA site on the chromosome 11. This ITS was presumably remnant of the chromosome rearrangement(s) leading to the genomic redistribution of the rDNA sequences. Comparative analysis of the cytogenetic data among several related salmonid species confirmed huge variation in the number and the chromosomal location of rRNA gene clusters in the Salvelinus genome.

  2. On the relative effect of spawning asynchrony, sperm quantity and sperm quality on paternity under sperm competition in an external fertilizer

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    Torvald Blikra Egeland


    Full Text Available How much of a fitness benefit is obtained by dominant males of external fertilizers from releasing ejaculates in synchrony with female egg-release when engaging in sperm competition, and what is the most important sperm trait for paternity in these situations? The Arctic charr (Salvelinus alpinus is an external fertilizer experiencing intense male-male competition over reproductive opportunities including sperm competition. To compensate for their disadvantage the sneaker males, which often spawn out of synchrony with the female, produce more and faster sperm than the guarding males. We used controlled in vitro fertilization trials with experimentally produced dominant and subordinate, sneaker males to test what effect relative synchrony in gamete release, sperm quality (i.e., motility and velocity and sperm quantity have on a male’s fertilization success in pair-wise sperm competitions. When the sneaker males released ejaculates after the guarding male there was no overall difference in fertilization success. The quality (i.e., motility and velocity of a male’s sperm relative to that of the competing male was the best predictor of male fertilization success regardless of their mating tactic and spawning synchrony. The relative number of sperm cells also had an effect on fertilization success, but mainly when the dominant and sneaker male ejaculated synchronously. Our close imitation of natural sperm competition in charr shows that the sneaker males of external fertilizing species may fully compensate for their disadvantaged mating role by producing ejaculates of higher quality - an adjustment strangely not met by dominants.

  3. Temperature, pressure and light data collected by attached Archival Transmitting Tags to Salvelinus malma (Dolly Varden trout) in the Wulik River, Alaska, during 2012-06 to 2013-10 (NODC Accession 0119954) (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains data collected by electronic tags (Pop-up Satellite Archival Transmitting) attached to Salvelinus malma (Dolly Varden trout) in the Wulik...

  4. Baetis (Baetis) cypronyx sp. n., a new species of the Baetis alpinus species-group (Insecta, Ephemeroptera, Baetidae) from Cyprus, with annotated checklist of Baetidae in the Mediterranean islands (United States)

    Godunko, Roman J.; Soldán, Tomáš; Staniczek, Arnold H.


    Abstract A detailed description of the larvae of Baetis (Baetis) cypronyx sp. n., a representative of the Baetis alpinus species-group within the mayfly family Baetidae, is provided, including a differential diagnosis with regard to closely related species of the group, especially Baetis melanonyx (Pictet, 1843) and Baetis baroukianus Thomas & Dia, 1984. The new species is mainly distinguished by mouthparts (i.e. the shape and setation of labrum, maxillary and labial palps, details of paraglossae and mandibular incisors), setation of legs and abdominal terga, and length of paracercus. All available data on the biology of this putative endemic species of Cyprus are summarized. Annotated distributional data of the 33 species of Baetidae so far recorded from the Mediterranean islands are given, including new records and also including first data from Malta. PMID:28144182

  5. New parasites and predators follow the introduction of two fish species to a subarctic lake: implications for food-web structure and functioning (United States)

    Amundsen, Per-Arne; Lafferty, Kevin D.; Knudsen, Rune; Primicerio, Raul; Kristoffersen, Roar; Klemetsen, Anders; Kuris, Armand M.


    Introduced species can alter the topology of food webs. For instance, an introduction can aid the arrival of free-living consumers using the new species as a resource, while new parasites may also arrive with the introduced species. Food-web responses to species additions can thus be far more complex than anticipated. In a subarctic pelagic food web with free-living and parasitic species, two fish species (arctic charr Salvelinus alpinus and three-spined stickleback Gasterosteus aculeatus) have known histories as deliberate introductions. The effects of these introductions on the food web were explored by comparing the current pelagic web with a heuristic reconstruction of the pre-introduction web. Extinctions caused by these introductions could not be evaluated by this approach. The introduced fish species have become important hubs in the trophic network, interacting with numerous parasites, predators and prey. In particular, five parasite species and four predatory bird species depend on the two introduced species as obligate trophic resources in the pelagic web and could therefore not have been present in the pre-introduction network. The presence of the two introduced fish species and the arrival of their associated parasites and predators increased biodiversity, mean trophic level, linkage density, and nestedness; altering both the network structure and functioning of the pelagic web. Parasites, in particular trophically transmitted species, had a prominent role in the network alterations that followed the introductions.

  6. Feeding habits of the alien brook trout Salvelinus fontinalis and the native brown trout Salmo trutta in Czech mountain streams

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    Horká Petra


    Full Text Available Quantifying patterns of prey resource use is fundamental to identify mechanisms enabling the coexistence of related fish species. Trophic interactions between the native brown trout, Salmo trutta, and the introduced brook trout, Salvelinus fontinalis, were studied monthly from May to October in three mountain streams in Central Europe (Czech Republic. To evaluate whether the feeding habits differ between separated and coexisting populations of these species, one locality where both species coexist, and two allopatric populations of either species were studied. Across the study period, the mean stomach fullness of fish varied, being highest in spring and declining through autumn. The diet overlap (Schoener's overlap index between the species increased through the studied season (from 54.5% in July to 81.5% in October. In allopatry, both species had nearly the same feeding habits. However, in sympatry, brook trout consumed higher proportion of terrestrial invertebrates, while brown trout showed no changes either in the proportions of aquatic and terrestrial prey utilized or in the selectivity for prey categories in comparison to allopatric conditions. The dietary shift observed for brook trout, but not for brown trout, suggests that brown trout is a stronger competitor in the studied sympatric locality, leading the brook trout to change its feeding habits to reduce interspecific competition.

  7. Breaking the speed limit--comparative sprinting performance of brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta) (United States)

    Castro-Santos, Theodore; Sanz-Ronda, Francisco Javier; Ruiz-Legazpi, Jorge


    Sprinting behavior of free-ranging fish has long been thought to exceed that of captive fish. Here we present data from wild-caught brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta), volitionally entering and sprinting against high-velocity flows in an open-channel flume. Performance of the two species was nearly identical, with the species attaining absolute speeds > 25 body lengths·s−1. These speeds far exceed previously published observations for any salmonid species and contribute to the mounting evidence that commonly accepted estimates of swimming performance are low. Brook trout demonstrated two distinct modes in the relationship between swim speed and fatigue time, similar to the shift from prolonged to sprint mode described by other authors, but in this case occurring at speeds > 19 body lengths·s−1. This is the first demonstration of multiple modes of sprint swimming at such high swim speeds. Neither species optimized for distance maximization, however, indicating that physiological limits alone are poor predictors of swimming performance. By combining distributions of volitional swim speeds with endurance, we were able to account for >80% of the variation in distance traversed by both species.

  8. New insight into the spawning behavior of lake trout, Salvelinus namaycush, from a recovering population in the Laurentian Great Lakes (United States)

    Binder, Thomas R.; Thompson, Henry T.; Muir, Andrew M.; Riley, Stephen C.; Marsden, J. Ellen; Bronte, Charles R.; Krueger, Charles C.


    Spawning behavior of lake trout, Salvelinus namaycush, is poorly understood, relative to stream-dwelling salmonines. Underwater video records of spawning in a recovering population from the Drummond Island Refuge (Lake Huron) represent the first reported direct observations of lake trout spawning in the Laurentian Great Lakes. These observations provide new insight into lake trout spawning behavior and expand the current conceptual model. Lake trout spawning consisted of at least four distinct behaviors: hovering, traveling, sinking, and gamete release. Hovering is a new courtship behavior that has not been previously described. The apparent concentration of hovering near the margin of the spawning grounds suggests that courtship and mate selection might be isolated from the spawning act (i.e., traveling, sinking, and gamete release). Moreover, we interpret jockeying for position displayed by males during traveling as a unique form of male-male competition that likely evolved in concert with the switch from redd-building to itinerant spawning in lake trout. Unlike previous models, which suggested that intra-sexual competition and mate selection do not occur in lake trout, our model includes both and is therefore consistent with evolutionary theory, given that the sex ratio on spawning grounds is skewed heavily towards males. The model presented in this paper is intended as a working hypothesis, and further revision may become necessary as we gain a more complete understanding of lake trout spawning behavior.

  9. Intraspecific variation in thermal tolerance and acclimation capacity in brook trout (Salvelinus fontinalis): physiological implications for climate change. (United States)

    Stitt, Bradley C; Burness, Gary; Burgomaster, Kirsten A; Currie, Suzanne; McDermid, Jenni L; Wilson, Chris C


    Cold-water fishes are becoming increasingly vulnerable as changing thermal conditions threaten their future sustainability. Thermal stress and habitat loss from increasing water temperatures are expected to impact population viability, particularly for inland populations with limited adaptive resources. Although the long-term persistence of cold-adapted species will depend on their ability to cope with and adapt to changing thermal conditions, very little is known about the scope and variation of thermal tolerance within and among conspecific populations and evolutionary lineages. We studied the upper thermal tolerance and capacity for acclimation in three captive populations of brook trout (Salvelinus fontinalis) from different ancestral thermal environments. Populations differed in their upper thermal tolerance and capacity for acclimation, consistent with their ancestry: the northernmost strain (Lake Nipigon) had the lowest thermal tolerance, while the strain with the most southern ancestry (Hill's Lake) had the highest thermal tolerance. Standard metabolic rate increased following acclimation to warm temperatures, but the response to acclimation varied among strains, suggesting that climatic warming may have differential effects across populations. Swimming performance varied among strains and among acclimation temperatures, but strains responded in a similar way to temperature acclimation. To explore potential physiological mechanisms underlying intraspecific differences in thermal tolerance, we quantified inducible and constitutive heat shock proteins (HSP70 and HSC70, respectively). HSPs were associated with variation in thermal tolerance among strains and acclimation temperatures; HSP70 in cardiac and white muscle tissues exhibited similar patterns, whereas expression in hepatic tissue varied among acclimation temperatures but not strains. Taken together, these results suggest that populations of brook trout will vary in their ability to cope with a

  10. Evolution and origin of sympatric shallow-water morphotypes of Lake Trout, Salvelinus namaycush, in Canada's Great Bear Lake. (United States)

    Harris, L N; Chavarie, L; Bajno, R; Howland, K L; Wiley, S H; Tonn, W M; Taylor, E B


    Range expansion in north-temperate fishes subsequent to the retreat of the Wisconsinan glaciers has resulted in the rapid colonization of previously unexploited, heterogeneous habitats and, in many situations, secondary contact among conspecific lineages that were once previously isolated. Such ecological opportunity coupled with reduced competition likely promoted morphological and genetic differentiation within and among post-glacial fish populations. Discrete morphological forms existing in sympatry, for example, have now been described in many species, yet few studies have directly assessed the association between morphological and genetic variation. Morphotypes of Lake Trout, Salvelinus namaycush, are found in several large-lake systems including Great Bear Lake (GBL), Northwest Territories, Canada, where several shallow-water forms are known. Here, we assess microsatellite and mitochondrial DNA variation among four morphotypes of Lake Trout from the five distinct arms of GBL, and also from locations outside of this system to evaluate several hypotheses concerning the evolution of morphological variation in this species. Our data indicate that morphotypes of Lake Trout from GBL are genetically differentiated from one another, yet the morphotypes are still genetically more similar to one another compared with populations from outside of this system. Furthermore, our data suggest that Lake Trout colonized GBL following dispersal from a single glacial refugium (the Mississippian) and support an intra-lake model of divergence. Overall, our study provides insights into the origins of morphological and genetic variation in post-glacial populations of fishes and provides benchmarks important for monitoring Lake Trout biodiversity in a region thought to be disproportionately susceptible to impacts from climate change.

  11. Fine-scale population structure and riverscape genetics of brook trout (Salvelinus fontinalis) distributed continuously along headwater channel networks (United States)

    Kanno, Yoichiro; Vokoun, Jason C.; Letcher, Benjamin H.


    Linear and heterogeneous habitat makes headwater stream networks an ideal ecosystem in which to test the influence of environmental factors on spatial genetic patterns of obligatory aquatic species. We investigated fine-scale population structure and influence of stream habitat on individual-level genetic differentiation in brook trout (Salvelinus fontinalis) by genotyping eight microsatellite loci in 740 individuals in two headwater channel networks (7.7 and 4.4 km) in Connecticut, USA. A weak but statistically significant isolation-by-distance pattern was common in both sites. In the field, many tagged individuals were recaptured in the same 50-m reaches within a single field season (summer to fall). One study site was characterized with a hierarchical population structure, where seasonal barriers (natural falls of 1.5–2.5 m in height during summer base-flow condition) greatly reduced gene flow and perceptible spatial patterns emerged because of the presence of tributaries, each with a group of genetically distinguishable individuals. Genetic differentiation increased when pairs of individuals were separated by high stream gradient (steep channel slope) or warm stream temperature in this site, although the evidence of their influence was equivocal. In a second site, evidence for genetic clusters was weak at best, but genetic differentiation between individuals was positively correlated with number of tributary confluences. We concluded that the population-level movement of brook trout was limited in the study headwater stream networks, resulting in the fine-scale population structure (genetic clusters and clines) even at distances of a few kilometres, and gene flow was mitigated by ‘riverscape’ variables, particularly by physical barriers, waterway distance (i.e. isolation-by-distance) and the presence of tributaries.

  12. [Phylogeography of mitochondrial DNA in South Asian Dolly Varden char Salvelinus curilus Pallas, 1814 (Salmoniformes, Salmonidae): mediated gene introgression?]. (United States)

    Shed'ko, S V; Ginatulina, L K; Miroshnichenko, I L; Nemkova, G A


    In 41 individuals of South Asian Dolly Varden char Salvelinus curilus, nucleotide sequences of tRNA-Pro gene fragment (27 bp) and mtDNA control region (483-484 bp) were analyzed. The fish were collected in 20 localities covering virtually the whole range of the species: Kuril Islands, Sakhalin Island. and Primorye. In addition, six individuals of three other char species (S. albus, S. malma, and S. leucomaenis), which are closely related to S. curilus and inhabit the Russian Far East, were examined. In all, we detected 12 different variants of mtDNA haplotypes that formed three distinct groups differing in 14--20 nucleotide positions. The first group consisted of six haplotypes found in S. curilus in Kuril Islands, Sakhalin, and Primorye (mtDNA phylogroup OKHOTSKIA). The second group comprised four haplotypes representing the mtDNA phylogroup BERING, which had been described earlier (Brunner et al, 2001); they were found in S. curilus in Kuril Islands and Sakhalin, as well as in S. albus and S. malma in Kamchatka and northern Kurils. The third group included two haplotypes detected in S. leucomaenis. The existence of two mtDNA lineages (OKHOTSKIA and BERING) in S. curilus from Kurils and Sakhalin was explained by hybridization and DNA transfer from S. malma to S. curilus. The absence of the BERING haplotypes in S. curilus from Primorye water reservoirs is related to the physical isolation of the Sea of Okhotsk and Sea of Japan basins in past epochs. On the basis of comparing phylogenetic trees, constructed from the data on allozyme and mtDNA variation, we suggest that in this case, an indirect transfer of mtDNA in Alpinoid chars--> S. malma-->S. curilus chain could occur.

  13. Estimates of lake trout (Salvelinus namaycush) diet in Lake Ontario using two and three isotope mixing models (United States)

    Colborne, Scott F.; Rush, Scott A.; Paterson, Gordon; Johnson, Timothy B.; Lantry, Brian F.; Fisk, Aaron T.


    Recent development of multi-dimensional stable isotope models for estimating both foraging patterns and niches have presented the analytical tools to further assess the food webs of freshwater populations. One approach to refine predictions from these analyses is to include a third isotope to the more common two-isotope carbon and nitrogen mixing models to increase the power to resolve different prey sources. We compared predictions made with two-isotope carbon and nitrogen mixing models and three-isotope models that also included sulphur (δ34S) for the diets of Lake Ontario lake trout (Salvelinus namaycush). We determined the isotopic compositions of lake trout and potential prey fishes sampled from Lake Ontario and then used quantitative estimates of resource use generated by two- and three-isotope Bayesian mixing models (SIAR) to infer feeding patterns of lake trout. Both two- and three-isotope models indicated that alewife (Alosa pseudoharengus) and round goby (Neogobius melanostomus) were the primary prey items, but the three-isotope models were more consistent with recent measures of prey fish abundances and lake trout diets. The lake trout sampled directly from the hatcheries had isotopic compositions derived from the hatchery food which were distinctively different from those derived from the natural prey sources. Those hatchery signals were retained for months after release, raising the possibility to distinguish hatchery-reared yearlings and similarly sized naturally reproduced lake trout based on isotopic compositions. Addition of a third-isotope resulted in mixing model results that confirmed round goby have become an important component of lake trout diet and may be overtaking alewife as a prey resource.

  14. Sibship reconstruction for inferring mating systems, dispersal and effective population size in headwater brook trout (Salvelinus fontinalis) populations (United States)

    Kanno, Yoichiro; Vokoun, Jason C.; Letcher, Benjamin H.


    Brook trout Salvelinus fontinalis populations have declined in much of the native range in eastern North America and populations are typically relegated to small headwater streams in Connecticut, USA. We used sibship reconstruction to infer mating systems, dispersal and effective population size of resident (non-anadromous) brook trout in two headwater stream channel networks in Connecticut. Brook trout were captured via backpack electrofishing using spatially continuous sampling in the two headwaters (channel network lengths of 4.4 and 7.7 km). Eight microsatellite loci were genotyped in a total of 740 individuals (80–140 mm) subsampled in a stratified random design from all 50 m-reaches in which trout were captured. Sibship reconstruction indicated that males and females were both mostly polygamous although single pair matings were also inferred. Breeder sex ratio was inferred to be nearly 1:1. Few large-sized fullsib families (>3 individuals) were inferred and the majority of individuals were inferred to have no fullsibs among those fish genotyped (family size = 1). The median stream channel distance between pairs of individuals belonging to the same large-sized fullsib families (>3 individuals) was 100 m (range: 0–1,850 m) and 250 m (range: 0–2,350 m) in the two study sites, indicating limited dispersal at least for the size class of individuals analyzed. Using a sibship assignment method, the effective population size for the two streams was estimated at 91 (95%CI: 67–123) and 210 (95%CI: 172–259), corresponding to the ratio of effective-to-census population size of 0.06 and 0.12, respectively. Both-sex polygamy, low variation in reproductive success, and a balanced sex ratio may help maintain genetic diversity of brook trout populations with small breeder sizes persisting in headwater channel networks.

  15. pH preference and avoidance responses of adult brook trout Salvelinus fontinalis and brown trout Salmo trutta. (United States)

    Fost, B A; Ferreri, C P


    The pH preferred and avoided by wild, adult brook trout Salvelinus fontinalis and brown trout Salmo trutta was examined in a series a laboratory tests using gradual and steep-gradient flow-through aquaria. The results were compared with those published for the observed segregation patterns of juvenile S. fontinalis and S. trutta in Pennsylvania streams. The adult S. trutta tested showed a preference for pH 4·0 while adult S. fontinalis did not prefer any pH within the range tested. Salmo trutta are not found in Pennsylvania streams with a base-flow pH pH well above 4·0. Adult S. trutta displayed a lack of avoidance at pH below 5·0, as also reported earlier for juveniles. The avoidance pH of wild, adult S. fontinalis (between pH 5·5 and 6·0) and S. trutta (between pH 6·5 and 7·0) did not differ appreciably from earlier study results for the avoidance pH of juvenile S. fontinalis and S. trutta. A comparison of c.i. around these avoidance estimates indicates that avoidance pH is similar among adult S. fontinalis and S. trutta in this study. The limited overlap of c.i. for avoidance pH values for the two species, however, suggests that some S. trutta will display avoidance at a higher pH when S. fontinalis will not. The results of this study indicate that segregation patterns of adult S. fontinalis and S. trutta in Pennsylvania streams could be related to pH and that competition with S. trutta could be mediating the occurrence of S. fontinalis at some pH levels.

  16. Sampling large geographic areas for rare species using environmental DNA: a study of bull trout Salvelinus confluentus occupancy in western Montana. (United States)

    McKelvey, K S; Young, M K; Knotek, W L; Carim, K J; Wilcox, T M; Padgett-Stewart, T M; Schwartz, M K


    This study tested the efficacy of environmental DNA (eDNA) sampling to delineate the distribution of bull trout Salvelinus confluentus in headwater streams in western Montana, U.S.A. Surveys proved fast, reliable and sensitive: 124 samples were collected across five basins by a single crew in c. 8 days. Results were largely consistent with past electrofishing, but, in a basin where S. confluentus were known to be scarce, eDNA samples indicated that S. confluentus were more broadly distributed than previously thought.

  17. Bull trout (Salvelinus confluentus) movement in relation to water temperature, season, and habitat features in Arrowrock Reservoir, Idaho, 2012 (United States)

    Maret, Terry R.; Schultz, Justin E.


    Acoustic telemetry was used to determine spring to summer (April–August) movement and habitat use of bull trout (Salvelinus confluentus) in Arrowrock Reservoir (hereafter “Arrowrock”), a highly regulated reservoir in the Boise River Basin of southwestern Idaho. Water management practices annually use about 86 percent of the reservoir water volume to satisfy downstream water demands. These practices might be limiting bull trout habitat and movement patterns. Bull trout are among the more thermally sensitive coldwater species in North America, and the species is listed as threatened throughout the contiguous United States under the Endangered Species Act. Biweekly water-temperature and dissolved-oxygen profiles were collected by the Bureau of Reclamation at three locations in Arrowrock to characterize habitat conditions for bull trout. Continuous streamflow and water temperature also were measured immediately upstream of the reservoir on the Middle and South Fork Boise Rivers, which influence habitat conditions in the riverine zones of the reservoir. In spring 2012, 18 bull trout ranging in total length from 306 to 630 millimeters were fitted with acoustic transmitters equipped with temperature and depth sensors. Mobile boat tracking and fixed receivers were used to detect released fish. Fish were tagged from March 28 to April 20 and were tracked through most of August. Most bull trout movements were detected in the Middle Fork Boise River arm of the reservoir. Fifteen individual fish were detected at least once after release. Water surface temperature at each fish detection location ranged from 6.0 to 16.2 degrees Celsius (°C) (mean=10.1°C), whereas bull trout body temperatures were colder, ranging from 4.4 to 11.6°C (mean=7.3°C). Bull trout were detected over deep-water habitat, ranging from 8.0 to 42.6 meters (m) (mean=18.1 m). Actual fish depths were shallower than total water depth, ranging from 0.0 to 24.5 m (mean=6.7 m). The last bull trout was

  18. [Differentiation of Dolly Varden char Salvelinus malma from Asia and North America inferred from PCR-RFLP analysis of mitochondrial DNA]. (United States)

    Oleĭnik, A G; Skurikhina, L A; Brykov, V A; Crane, P A; Wenburg, J K


    Genetic differentiation of Dolly Varden char Salvelinus malma Walbaum from the Asian and North American Pacific coasts was studied. We examined restriction fragment length polymorphism of three mitochondrial DNA (mtDNA) fragments amplified in polymerase chain reaction, which encoded four NADH dehydrogenase subunits, the cytochrome b gene, and a D-loop segment. The mtDNA haplotypes were shown to form three phylogenetic groups, whose geographic distribution corresponded to three Dolly Varden subspecies: S. malma malma, S. malma krascheninnikovi, and S. malma lordi. The nucleotide sequence divergence between S. malma malma and S. malma krascheninnikovi was 3.8%; between S. malma malma and S. malma lordi, 3.1%; and between S. malma krascheninnikovi and S. malma lordi, 2.5%. The northern Dolly Varden S. malma malma from Asia was shown to be genetically identical to that from North America.

  19. Behavioural and physiological responses of brook trout Salvelinus fontinalis to midwinter flow reduction in a small ice-free mountain stream. (United States)

    Krimmer, A N; Paul, A J; Hontela, A; Rasmussen, J B


    This study presents an experimental analysis of the effects of midwinter flow reduction (50-75%, reduction in discharge in 4 h daily pulses) on the physical habitat and on behaviour and physiology of overwintering brook trout Salvelinus fontinalis in a small mountain stream. Flow reduction did not result in significant lowering of temperature or formation of surface or subsurface ice. The main findings were (1) daily movement by S. fontinalis increased (c. 2·5-fold) during flow reduction, but was limited to small-scale relocations (banks were the preferred habitat and availability of these habitats was reduced during flow reduction. (3) Although both experimental and reference fish did lose mass and condition during the experiment, no effects of flow reduction on stress indicators (blood cortisol or glucose) or bioenergetics (total body fat, water content or mass loss) were detected, probably because access to the preferred type of cover remained available. Like other salmonids, S. fontinalis moves little and seeks physical cover during winter. Unlike many of the more studied salmonids, however, this species overwinters successfully in small groundwater-rich streams that often remain ice-free, and this study identifies undercut banks as the critical winter habitat rather than substratum cover.

  20. Perturbation in protein expression of the sterile salmonid hybrids between female brook trout Salvelinus fontinalis and male masu salmon Oncorhynchus masou during early spermatogenesis. (United States)

    Zheng, Liang; Senda, Yoshie; Abe, Syuiti


    Most males and females of intergeneric hybrid (BM) between female brook trout (Bt) Salvelinus fontinalis and male masu salmon (Ms) Oncorhynchus masou had undeveloped gonads, with abnormal germ cell development shown by histological examination. To understand the cause of this hybrid sterility, expression profiles of testicular proteins in the BM and parental species were examined with 2-DE coupled with MALDI-TOF/TOF MS. Compared with the parental species, more than 60% of differentially expressed protein spots were down-regulated in BM. A total of 16 up-regulated and 48 down-regulated proteins were identified in BM. Up-regulated were transferrin and other somatic cell-predominant proteins, whereas down-regulated were some germ cell-specific proteins such as DEAD box RNA helicase Vasa. Other pronouncedly down-regulated proteins included tubulins and heat shock proteins that are supposed to have roles in spermatogenesis. The present findings suggest direct association of the observed perturbation in protein expression with the failure of spermatogenesis and the sterility in the examined salmonid hybrids.

  1. Differential growth in estuarine and freshwater habitats indicated by plasma IGF1 concentrations and otolith chemistry in Dolly Varden Salvelinus malma. (United States)

    Bond, M H; Beckman, B R; Rohrbach, L; Quinn, T P


    This study employed a combination of otolith microchemistry to indicate the recent habitat use, and plasma concentrations of the hormone insulin-like growth factor 1 (IGF1) as an index of recent growth rate, to demonstrate differences in growth and habitat use by Dolly Varden Salvelinus malma occupying both freshwater and estuarine habitats in south-west Alaska. Extensive sampling in all habitats revealed that fish had higher IGF1 levels in estuarine compared to lake habitats throughout the summer, and that the growth rates in different habitats within the estuary varied seasonally. In addition, otolith microchemistry indicated differentiation in estuarine habitat use among individual S. malma throughout summer months. Although growth in the estuary was higher than in fresh water in nearly all sites and months, the benefits and use of the estuarine habitats varied on finer spatial scales. Therefore, this study further illustrates the diverse life histories of S. malma and indicates an evaluation of the benefits of marine waters needs to include sub-estuary scale habitat use.

  2. [Developmental abnormalities in salmonids (Salmonidae) under the conditions of large-scale volcanic pollution of their spawning ground (using dolly varden Salvelinus malma as an example)]. (United States)

    Esin, E V


    Rivers originating from the areas of active volcanism in Kamchatka serve a spawning ground for anadromous and resident populations of dolly varden (Salvelinus malma). In some cases, watercourses with a long-term continuous spawning of S. malma are subjected to chronic pollution with dissolved toxicants and suspended mineral particles. The revealed development conditions range from background ("clean" rivers) to critical (most "polluted" rivers). Medium pollution leads to the development of hatchlings with abnormalities in the ethmoidal head segment, lower jaw, operculum, lobes of the paired fins, and axial skeleton (up to 40% of all specimens). Delayed ossification of skeletal elements takes place. Abnormalities in the development of spinous processes occur more often (up to 49-55% compared to 25-30% in the background areas). The average number of asymmetries per specimen.(in four bilateral structures) increases from 1.1-1.4 to 1.7- 2.5. Similar developmental abnormalities have been registered in underyearlings, both anadromous and resident, influenced by various pollutant combinations. While fish continue to grow, some of them die because of abnormalities; thus, their frequency in 3-year-old specimens nears the background one. Upon extreme pollution, deviant specimens are sampled at earlier developmental stages and characterized by a lower frequency of morphological abnormalities.

  3. Assessing the impacts of river regulation on native bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarkii lewisi) habitats in the upper Flathead River, Montana, USA (United States)

    Muhlfeld, Clint C.; Jones, Leslie A.; Kotter, D.; Miller, William J.; Geise, Doran; Tohtz, Joel; Marotz, Brian


    Hungry Horse Dam on the South Fork Flathead River, Montana, USA, has modified the natural flow regimen for power generation, flood risk management and flow augmentation for anadromous fish recovery in the Columbia River. Concern over the detrimental effects of dam operations on native resident fishes prompted research to quantify the impacts of alternative flow management strategies on threatened bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarkii lewisi) habitats. Seasonal and life‐stage specific habitat suitability criteria were combined with a two‐dimensional hydrodynamic habitat model to assess discharge effects on usable habitats. Telemetry data used to construct seasonal habitat suitability curves revealed that subadult (fish that emigrated from natal streams to the river system) bull trout move to shallow, low‐velocity shoreline areas at night, which are most sensitive to flow fluctuations. Habitat time series analyses comparing the natural flow regimen (predam, 1929–1952) with five postdam flow management strategies (1953–2008) show that the natural flow conditions optimize the critical bull trout habitats and that the current strategy best resembles the natural flow conditions of all postdam periods. Late summer flow augmentation for anadromous fish recovery, however, produces higher discharges than predam conditions, which reduces the availability of usable habitat during this critical growing season. Our results suggest that past flow management policies that created sporadic streamflow fluctuations were likely detrimental to resident salmonids and that natural flow management strategies will likely improve the chances of protecting key ecosystem processes and help to maintain and restore threatened bull trout and westslope cutthroat trout populations in the upper Columbia River Basin.

  4. Investigations of Bull Trout (Salvelinus Confluentus), Steelhead Trout (Oncorhynchus Mykiss), and Spring Chinook Salmon (O. Tshawytscha) Interactions in Southeast Washington Streams. Final Report 1992.

    Energy Technology Data Exchange (ETDEWEB)

    Underwood, Keith D.


    The goal of this two year study was to determine if supplementation with hatchery reared steelhead trout (Oncorhynchus mykiss) and spring chinook salmon (O. tshawytscha) negatively impacted wild native bull trout (Salvelinus confluentus) through competitive interactions. Four streams with varying levels of fish supplementation activity were sampled in Southeast Washington. Tasks performed during this study were population density, relative abundance, microhabitat utilization, habitat availability, diet analysis, bull trout spawning ground surveys, radio telemetry of adult bull trout, and growth analysis. Results indicate that bull trout overlapped geographically with the supplemented species in each of the study streams suggesting competition among species was possible. Within a stream, bull trout and the supplemented species utilized dissimilar microhabitats and microhabitat utilization by each species was the same among streams suggesting that there was no shifts in microhabitat utilization among streams. The diet of bull trout and O. mykiss significantly overlapped in each of the study streams. The stream most intensely supplemented contained bull trout with the slowest growth and the non-supplemented stream contained bull trout with the fastest growth. Conversely, the stream most intensely supplemented contain steelhead with the fastest growth and the non-supplemented stream contained steelhead with the slowest growth. Growth indicated that bull trout may have been negatively impacted from supplementation, although other factors may have contributed. At current population levels, and current habitat quantity and quality, no impacts to bull trout as a result of supplementation with hatchery reared steelhead trout and spring chinook salmon were detected. Project limitations and future research recommendations are discussed.

  5. Assessing the influence of migration barriers and feeding ecology on total mercury concentrations in Dolly Varden (Salvelinus malma) from a glaciated and non-glaciated stream. (United States)

    Cyr, Andrew; Sergeant, Christopher J; Lopez, Juan Andres; O'Hara, Todd


    Assimilation of mercury (Hg) into food webs is directly influenced by ecological factors such as local habitat characteristics, species feeding behavior, and movement patterns. Total Hg concentrations ([THg]) in biota from Subarctic latitudes are driven both by broad spatial processes such as long-range atmospheric transport and more local influences such as biovectors and geology. Thus, even relatively pristine protected lands such as national parks are experiencing Hg accumulation. We analyzed [THg] and stable isotopes of carbon (δ(13)C) and nitrogen (δ(15)N) in 104 Dolly Varden (Salvelinus malma) collected from two rivers in southeastern Alaska, upstream and downstream of apparent anadromous migration barriers in watersheds with and without glacial coverage. To assess the potential magnitude of marine-derived THg returning to freshwater, we analyzed [THg] in ten adult pink salmon from each study system. There were no differences in Dolly Varden mean [THg] between sites after the data were standardized for fork length, but unadjusted [THg] varied relative to fish size and δ(15)N values. While previous studies generally show that [THg] increases with higher δ(15)N values, we found that Dolly Varden below migration barriers and foraging on salmon eggs had the highest δ(15)N values among all sampled individuals, but the lowest [THg]. Dolly Varden residing below anadromous barriers had δ(13)C values consistent with marine influence. Since salmon eggs typically have low [Hg], our results suggest that abundant salmon populations and the dietary subsidy they provide may reduce the annual exposure to [Hg] in egg-eating stream fishes such as Dolly Varden. In addition to identifying a suitable species for freshwater Hg monitoring in southeastern Alaska, our study more broadly implies that river characteristics, location within a river, fish size, and feeding ecology are important factors influencing Hg accumulation.

  6. The effects of total dissolved solids on egg fertilization and water hardening in two salmonids--Arctic Grayling (Thymallus arcticus) and Dolly Varden (Salvelinus malma). (United States)

    Brix, Kevin V; Gerdes, Robert; Curry, Nathan; Kasper, Amanda; Grosell, Martin


    Previous studies have indicated that salmonid fertilization success may be very sensitive to elevated concentrations of total dissolved solids (TDS) with effects at concentrations as low as 250mgl(-1) being reported. However, interpretation of these studies is complicated by poor control performance and variable concentration response relationships. To address this, a series of experiments were performed to evaluate TDS effects on Arctic Grayling (Thymallus arcticus) and Dolly Varden (Salvelinus malma) fertilization success and identify possible mechanisms for previously observed test variability and any observed effects of TDS. Results indicate that some of the experiments reported here were likely confounded by extended milt holding times prior to experiment initiation. Milt holding times >6h were shown to significantly reduce control fertilization and corresponding concentration response relationships were variable. When milt holding time was minimized during fertilization experiments, consistent control performance with >90% control fertilization was achieved and consistent concentration response relationships were observed for both species examined. Experiments performed under these conditions indicate that Arctic Grayling and Dolly Varden fertilization success is not sensitive to elevated TDS with EC20s (concentration causing 20% effect) of >2782 and >1817mgl(-1) (the highest concentrations tested), respectively. However, TDS was shown to significantly affect embryo water absorption during the water hardening phase immediately following fertilization. The lowest observable effect concentrations (LOECs) for this endpoint were 1402 and 964mgl(-1) for Arctic Grayling and Dolly Varden, respectively. The effect of reduced embryo turgidity, due to impaired water absorption, on resistance to mechanical damage under real world conditions needs further investigation in order to understand the implications of this observed effect.

  7. An ecological risk assessment of the acute and chronic toxicity of the herbicide picloram to the threatened bull trout (salvelinus confluentus) and the rainbow trout (onchorhyncus mykiss) (United States)

    Fairchild, J.F.; Feltz, K.P.; Sappington, L.C.; Allert, A.L.; Nelson, K.J.; Valle, J.


    We conducted acute and chronic toxicity studies of the effects of picloram acid on the threatened bull trout (Salvelinus confluentus) and the standard coldwater surrogate rainbow trout (Oncorhynchus mykiss). Juvenile fish were chronically exposed for 30 days in a proportional flow-through diluter to measured concentrations of 0, 0.30, 0.60, 1.18, 2.37, and 4.75 mg/L picloram. No mortality of either species was observed at the highest concentration. Bull trout were twofold more sensitive to picloram (30-day maximum acceptable toxic concentration of 0.80 mg/L) compared to rainbow trout (30-day maximum acceptable toxic concentration of 1.67 mg/L) based on the endpoint of growth. Picloram was acutely toxic to rainbow trout at 36 mg/L (96-h ALC50). The acute:chronic ratio for rainbow trout exposed to picloram was 22. The chronic toxicity of picloram was compared to modeled and measured environmental exposure concentrations (EECs) using a four-tiered system. The Tier 1, worst-case exposure estimate, based on a direct application of the current maximum use rate (1.1 kg/ha picloram) to a standardized aquatic ecosystem (water body of 1-ha area and 1-m depth), resulted in an EEC of 0.73 mg/L picloram and chronic risk quotients of 0.91 and 0.44 for bull trout and rainbow trout, respectively. Higher-tiered exposure estimates reduced chronic risk quotients 10-fold. Results of this study indicate that picloram, if properly applied according to the manufacturer's label, poses little risk to the threatened bull trout or rainbow trout in northwestern rangeland environments on either an acute or a chronic basis. ?? 2008 Springer Science+Business Media, LLC.

  8. Investigations of Bull Trout (Salvelinus Confluentus), Steelhead Trout (Oncorhynchus Mykiss), and Spring Chinook Salmon (O. Tshawytscha) Interactions in Southeast Washington Streams : 1991 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Steven W.


    Bull trout (Salvelinus confluentus) are native to many tributaries of the Snake River in southeast Washington. The Washington Department of Wildlife (WDW) and the American Fisheries Society (AFS) have identified bull trout as a species of special concern which means that they may become threatened or endangered by relatively, minor disturbances to their habitat. Steelhead trout/rainbow trout (Oncorhynchus mykiss) and spring chinook salmon (O.tshawytscha) are also native to several tributaries of the Snake river in southeast Washington. These species of migratory fishes are depressed, partially due to the construction of several dams on the lower Snake river. In response to decreased run size, large hatchery program were initiated to produce juvenile steelhead and salmon to supplement repressed tributary stocks, a practice known as supplementation. There is a concern that supplementing streams with artificially high numbers of steelhead and salmon may have an impact on resident bull trout in these streams. Historically, these three species of fish existed together in large numbers, however, the amount of high-quality habitat necessary for reproduction and rearing has been severely reduced in recent years, as compared to historic amounts. The findings of the first year of a two year study aimed at identifying species interactions in southeast Washington streams are presented in this report. Data was collected to assess population dynamics; habitat utilization and preference, feeding habits, fish movement and migration, age, condition, growth, and the spawning requirements of bull trout in each of four streams. A comparison of the indices was then made between the study streams to determine if bull trout differ in the presence of the putative competitor species. Bull trout populations were highest in the Tucannon River (supplemented stream), followed by Mill Creek (unsupplemented stream). Young of the year bull trout utilized riffle and cascade habitat the most in all

  9. Clock genes and their genomic distributions in three species of salmonid fishes: Associations with genes regulating sexual maturation and cell cycling

    Directory of Open Access Journals (Sweden)

    Ferguson Moira M


    Full Text Available Abstract Background Clock family genes encode transcription factors that regulate clock-controlled genes and thus regulate many physiological mechanisms/processes in a circadian fashion. Clock1 duplicates and copies of Clock3 and NPAS2-like genes were partially characterized (genomic sequencing and mapped using family-based indels/SNPs in rainbow trout (RT(Oncorhynchus mykiss, Arctic charr (AC(Salvelinus alpinus, and Atlantic salmon (AS(Salmo salar mapping panels. Results Clock1 duplicates mapped to linkage groups RT-8/-24, AC-16/-13 and AS-2/-18. Clock3/NPAS2-like genes mapped to RT-9/-20, AC-20/-43, and AS-5. Most of these linkage group regions containing the Clock gene duplicates were derived from the most recent 4R whole genome duplication event specific to the salmonids. These linkage groups contain quantitative trait loci (QTL for life history and growth traits (i.e., reproduction and cell cycling. Comparative synteny analyses with other model teleost species reveal a high degree of conservation for genes in these chromosomal regions suggesting that functionally related or co-regulated genes are clustered in syntenic blocks. For example, anti-müllerian hormone (amh, regulating sexual maturation, and ornithine decarboxylase antizymes (oaz1 and oaz2, regulating cell cycling, are contained within these syntenic blocks. Conclusions Synteny analyses indicate that regions homologous to major life-history QTL regions in salmonids contain many candidate genes that are likely to influence reproduction and cell cycling. The order of these genes is highly conserved across the vertebrate species examined, and as such, these genes may make up a functional cluster of genes that are likely co-regulated. CLOCK, as a transcription factor, is found within this block and therefore has the potential to cis-regulate the processes influenced by these genes. Additionally, clock-controlled genes (CCGs are located in other life-history QTL regions within

  10. Farming different species in RAS in Nordic countries: Current status and future perspectives

    DEFF Research Database (Denmark)

    Dalsgaard, Anne Johanne Tang; Lund, Ivar; Thorarinsdottir, Ragnheidur


    (Oncorhynchus mykiss), European eel (Anguilla anguilla), pike perch (Stizostedion lucioperca), Arctic char (Salvelinus alpinus), sturgeon (order Acipenseriformes), Nile tilapia (Oreochromis niloticus), and European lobster (Homarus gammarus). High capital costs are one of the biggest challenges to sustainable...... RAS calling for large scale intensive productions to reduce investment -and operation costs. Consistent with this, production of Atlantic salmon smolts in indoor RAS and rainbow trout in outdoor Model-Trout-Farms (MTFs) have been the commercially most successful productions so far. Aside from end...

  11. Exposure and effects assessment of persistent organohalogen contaminants in arctic wildlife and fish. (United States)

    Letcher, Robert J; Bustnes, Jan Ove; Dietz, Rune; Jenssen, Bjørn M; Jørgensen, Even H; Sonne, Christian; Verreault, Jonathan; Vijayan, Mathilakath M; Gabrielsen, Geir W


    Persistent organic pollutants (POPs) encompass an array of anthropogenic organic and elemental substances and their degradation and metabolic byproducts that have been found in the tissues of exposed animals, especially POPs categorized as organohalogen contaminants (OHCs). OHCs have been of concern in the circumpolar arctic for decades. For example, as a consequence of bioaccumulation and in some cases biomagnification of legacy (e.g., chlorinated PCBs, DDTs and CHLs) and emerging (e.g., brominated flame retardants (BFRs) and in particular polybrominated diphenyl ethers (PBDEs) and perfluorinated compounds (PFCs) including perfluorooctane sulfonate (PFOS) and perfluorooctanic acid (PFOA) found in Arctic biota and humans. Of high concern are the potential biological effects of these contaminants in exposed Arctic wildlife and fish. As concluded in the last review in 2004 for the Arctic Monitoring and Assessment Program (AMAP) on the effects of POPs in Arctic wildlife, prior to 1997, biological effects data were minimal and insufficient at any level of biological organization. The present review summarizes recent studies on biological effects in relation to OHC exposure, and attempts to assess known tissue/body compartment concentration data in the context of possible threshold levels of effects to evaluate the risks. This review concentrates mainly on post-2002, new OHC effects data in Arctic wildlife and fish, and is largely based on recently available effects data for populations of several top trophic level species, including seabirds (e.g., glaucous gull (Larus hyperboreus)), polar bears (Ursus maritimus), polar (Arctic) fox (Vulpes lagopus), and Arctic charr (Salvelinus alpinus), as well as semi-captive studies on sled dogs (Canis familiaris). Regardless, there remains a dearth of data on true contaminant exposure, cause-effect relationships with respect to these contaminant exposures in Arctic wildlife and fish. Indications of exposure effects are largely

  12. 花糕红点鲑多态性微卫星筛选及鸭绿江种群遗传多样性分析%Screening of Polymorphisic Microsatellite and Genetic Diversity in Yalu River Population of Dolly Varden Salvelinus malma

    Institute of Scientific and Technical Information of China (English)



    The polymorphic primers for Dolly Varden Salvelinus malma as a rare and endangered cold-water species in China was screened from char S.confluentus by microsatellite,and the genetic diversity of the Yalu River population was analyzed.The results showed that 5 microsatellite primers screened from 10 microsatellite primers in Salvelinus malma were polymorphous in Dolly Varden.There were the number of alleles(Na) of 6~22(average 15),heteroerozygosity(H) of 0.4063~0.9333(average 0.7851) and polymorphic information content(PIC) of 0.716 4~0.919 8(average 0.8536) in Yalu River population of Dolly Varden.The findings indicated that the 5 primers from S.confluentus provided a good versatility in dolly varden,and a high level of genetic diversity in Yalu River population,which provides a genetics theoretical basis for the protection and management of germoplasm resources of Dolly Varden in China.%利用强壮红点鲑(Salvelinus confluentus)的微卫星筛选出适用于我国的珍稀濒危冷水性鱼类——花糕红点鲑(Salvelinus malma)的多态性引物,并分析其鸭绿江种群的遗传多样性。结果显示,在强壮红点鲑的10个微卫星引物中有5个在花糕红点鲑群体中具有多态性,鸭绿江种群的等位基因数(N)a为6~22(平均15),杂合度(H)为0.4063~0.9333(平均0.7851),多态信息含量(PIC)为0.7164~0.9198(平均0.8536)。强壮红点鲑微卫星引物在花糕红点鲑中具有很好的通用性,花糕红点鲑的鸭绿江种群具有较高的遗传多样性水平。本研究结果为我国花糕红点鲑种质资源保护和管理提供遗传学理论依据。

  13. Radioactive contamination of fishes in lake and streams impacted by the Fukushima nuclear power plant accident

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimura, Mayumi, E-mail: [Kansai Research Center, Forestry and Forest Products Research Institute, Nagaikyuutaro 68, Momoyama, Fushimi, Kyoto 612-0855 (Japan); Yokoduka, Tetsuya [Tochigi Prefectural Fisheries Experimental Station, Sarado 2599, Ohtawara, Tochigi 324-0404 (Japan)


    The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in March 2011 emitted radioactive substances into the environment, contaminating a wide array of organisms including fishes. We found higher concentrations of radioactive cesium ({sup 137}Cs) in brown trout (Salmo trutta) than in rainbow trout (Oncorhynchus nerka), and {sup 137}Cs concentrations in brown trout were higher in a lake than in a stream. Our analyses indicated that these differences were primarily due to differences in diet, but that habitat also had an effect. Radiocesium concentrations ({sup 137}Cs) in stream charr (Salvelinus leucomaenis) were higher in regions with more concentrated aerial activity and in older fish. These results were also attributed to dietary and habitat differences. Preserving uncontaminated areas by remediating soils and releasing uncontaminated fish would help restore this popular fishing area but would require a significant effort, followed by a waiting period to allow activity concentrations to fall below the threshold limits for consumption. - Highlight: • Concentration of {sup 137}Cs in brown trout was higher than in rainbow trout. • {sup 137}Cs concentration of brown trout in a lake was higher than in a stream. • {sup 137}Cs concentration of stream charr was higher in region with higher aerial activity. • Concentration of {sup 137}Cs in stream charr was higher in older fish. • Difference of contamination among fishes was due to difference in diet and habitat.

  14. Cloning and Tissue Expression Analysis ofPAX7 Gene in Grass Carp (Ctenopharyngodon idellus)%草鱼PAX7基因的克隆、序列分析及组织表达

    Institute of Scientific and Technical Information of China (English)

    甘甜; 冷向军; 郭婷; 胡静; 魏静; 李小勤


    Paired box gene 7(PAX7)is crucially important to the cellular renewal, differentiation and apoptosis, especially in neural crest development, gastrulation, and muscle self-renewal. ThePAX7 domains sequence is conserved among several species, such as zebrafish, apteronotidae, and rainbow trout, and the conserved sequence zebrafish was used to design degenerate primers for reverse-transcription PCR(RT-PCR). A partial sequence ofPAX7 from grass carp was obtained for a 645 bp segment encoding a 214 amino acid peptide, containing a paired box domain with 128 amino acids. The deduced protein showed homology to zebrafish(Danio rerio), apteronotidae(Sternopygus macrurus), Japanese Medaka(Oryzias latipes), gilthead bream(Sparus aurata), rainbow trout(Oncorhynchus mykiss), Atlantic salmon(Salmo salar), Arctic charr(Salvelinus alpinus), human(Homo sapiens), wild yak(Bos grunniens mutus), brown rat(Rattus norvegicus), and mouse(Mus musculus)with 90%-97% identities. Analysis of the PAX7 phylogenetic tree revealed that the grass carp joined with zebrafish, and there was a confluence of Japanese medaka, Arctic charr, Atlantic salmon, rainbow trout, apteronotidae and gilthead bream. The other branch was consisted of mouse, brown rat, wild yak and human. These results conformed to the traditional species classification evolution status. The expression in tissues was detected by Real-time quantitative PCR, which indicated that the highest level ofPAX7 gene expression was found in muscle, a lower expression level was found in foregut and skin, and the lowest detectable level was found in heart, brain, kidney and liver. The results are in agreement with the function of the gene.%配对盒基因7(Paired box 7 gene,PAX7)在神经嵴发育及原肠胚形成、肌肉自主更新与再生中扮演着重要角色,对细胞更新、分化、凋亡等起着十分重要的调控作用。参照GenBank中斑马鱼、线鳍电鳗和虹鳟等物种PAX7序列的保守区域设计简并引

  15. Geosmin causes off-flavour in arctic charr in recirculating aquaculture systems (United States)

    The “earthy” and “muddy” off-flavors in pond-reared fish are due to the presence of geosmin or 2-methylisoborneol (MIB) in the flesh of the fish. Similar off-flavors have been reported in fish raised in recirculating aquaculture systems (RAS); however, little information is available regarding the ...

  16. Development of a multichemical food web model: application to PBDEs in Lake Ellasjoen, Bear Island, Norway. (United States)

    Gandhi, Nilima; Bhavsar, Satyendra P; Gewurtz, Sarah B; Diamond, Miriam L; Evenset, Anita; Christensen, Guttorm N; Gregor, Dennis


    A multichemical food web model has been developed to estimate the biomagnification of interconverting chemicals in aquatic food webs. We extended a fugacity-based food web model for single chemicals to account for reversible and irreversible biotransformation among a parent chemical and transformation products, by simultaneously solving mass balance equations of the chemicals using a matrix solution. The model can be applied to any number of chemicals and organisms or taxonomic groups in a food web. The model was illustratively applied to four PBDE congeners, BDE-47, -99, -100, and -153, in the food web of Lake Ellasjøen, Bear Island, Norway. In Ellasjøen arctic char (Salvelinus alpinus), the multichemical model estimated PBDE biotransformation from higher to lower brominated congeners and improved the correspondence between estimated and measured concentrations in comparison to estimates from the single-chemical food web model. The underestimation of BDE-47, even after considering bioformation due to biotransformation of the otherthree congeners, suggests its formation from additional biotransformation pathways not considered in this application. The model estimates approximate values for congener-specific biotransformation half-lives of 5.7,0.8,1.14, and 0.45 years for BDE-47, -99, -100, and -153, respectively, in large arctic char (S. alpinus) of Lake Ellasjøen.

  17. [Karyological differences of the Northern Dolly Varden Salvelinus malma malma and the white char Salvelinus albus from the Kamchatka River basin]. (United States)

    Frolov, S V


    The karyotypes of northern Dolly Varden and white char, sympathrically inhabiting the Kamchatka River basin, were studied. The karyotype of Dolly Varden was stable: 2n = 78 and NF = 98 + 2, while in white char, polymorphism and mosaicism for the chromosome number were revealed: 2n = 76-79, NF = 98 + 2. Using a routine chromosome staining technique, the karyotype of white char (2n = 78) was shown to be identical to that of Dolly Varden. In both karyotypes, similar sets of marker chromosomes were present: two pairs of submetacentric (SM), one pair of submeta-subtelocentric (SM-ST), one pair of large acrocentric (A), and one pair of large sub-telocentric (ST) chromosomes. However, the karyotypes of Dolly Varden and white char differed in the number and location of nucleolus organizer regions (NORs). In Dolly Varden, single NORs located in the telomeric regions of the marker SM-ST chromosomes were observed. In white char, NORs were multiple and located both in the telomeric regions of the marker SM-ST chromosomes and on the short and long arms of large ST chromosomes. The identical marker chromosomes indicate considerable phylogenetic relatedness between Dolly Varden and white char from the Kamchatka River basin. Variation in NORs provides evidence for the reproductive isolation of these chars and their species status.

  18. Bilan des introductions de salmonidés dans les lacs et ruisseaux d'altitude des Hautes-Pyrénées

    Directory of Open Access Journals (Sweden)



    Full Text Available Les introductions de Salmonidés ont été importantes au cours des 60 dernières années dans les lacs et ruisseaux d'altitude des Hautes-Pyrénées. Six espèces de Salmonidés ont été introduites dans des milieux qui, pour la plupart, étaient vierges de populations piscicoles : la truite commune (Salmo trutta L., la truite arc-en-ciel (Oncorhynchus mykiss Walbaum, l'omble de fontaine (Salvelinus fontinalis Mitchill, l'omble chevalier (Salvelinus alpinus L., le cristivomer (Salvelinus namaycush Walbaum et le splake (Salvelinus fontinalis x Salvelinus namaycush. Dans de très nombreux cas, ces introductions ont abouti à des acclimatations. En revanche, les naturalisations sont beaucoup plus rares. Seules les espèces lacustres (cristivomer et omble chevalier se sont naturalisées dans la majorité des lacs où elles ont été introduites. Les conditions de reproduction constituent le facteur clé permettant d'expliquer la naturalisation des espèces. En ruisseau, il faut y ajouter la compétition avec l'espèce indigène (la truite commune, la pression halieutique ainsi que les conditions hivernales très rigoureuses. Les incidences écologiques des introductions sur les populations de truites communes indigènes sont faibles. En revanche, elles ne sont pas négligeables pour les populations de batraciens. Cette politique d'introduction a largement participé au développement de l'halieutisme dans ces milieux d'altitude. En cela, les introductions ont parfaitement répondu aux objectifs halieutiques qu'on leur avait fixés. L'acquisition de connaissances sur l'ensemble de la chaîne pyrénéenne constitue aujourd'hui une étape incontournable pour une politique de gestion globale des introductions.

  19. Integrating Traditional and Evolutionary Knowledge in Biodiversity Conservation: a Population Level Case Study

    Directory of Open Access Journals (Sweden)

    Dylan J. Fraser


    Full Text Available Despite their dual importance in the assessment of endangered/threatened species, there have been few attempts to integrate traditional ecological knowledge (TEK and evolutionary biology knowledge (EBK at the population level. We contrasted long-term aboriginal TEK with previously obtained EBK in the context of seasonal migratory habits and population biology of a salmonid fish, brook charr, (Salvelinus fontinalis inhabiting a large, remote postglacial lake. Compilation of TEK spanning four decades involved analytical workshops, semidirective interviews, and collaborative fieldwork with local aboriginal informants and fishing guides. We found that TEK complemented EBK of brook charr by providing concordant and additional information about (1 population viability; (2 breeding areas and migration patterns of divergent populations; and (3 the behavioral ecology of populations within feeding areas; all of which may ultimately affect the maintenance of population diversity. Aboriginal concerns related to human pressures on this species, not revealed by EBK, also help to focus future conservation initiatives for divergent populations and to encourage restoration of traditional fishing practices. However, relative to EBK, the relevance of TEK to salmonid biodiversity conservation was evident mainly at a smaller spatial scale, for example, that of individual rivers occupied by populations or certain lake sectors. Nevertheless, EBK was only collected over a 4-yr period, so TEK provided an essential long-term temporal window to evaluate population differences and persistence. We concluded that, despite different conceptual underpinnings, spatially and temporally varying TEK and EBK both contribute to the knowledge base required to achieve sustainability and effective biodiversity conservation planning for a given species. Such integration may be particularly relevant in many isolated regions, where intraspecific diversity can go unrecognized due to sparse

  20. Pseudolinkage of the duplicate loci for supernatant aspartate aminotransferase in brook trout, Salvelinus fontinalis. (United States)

    Wright, J E; May, B; Stoneking, M; Lee, G M


    Electrophoretic variation involving three alleles is described for the duplicated loci for supernatant aspartate aminotransferase (AAT-1,2), from muscle extracts of brook trout. Both loci exhibit largely disomic inheritance. Exceptional progeny types are proposed to be the result of a form of tetrasomic inheritance. Nonrandom segregation was found among the progeny of males doubly heterozygous for AAT markers; where so-called linkage phase was known, this nonrandom assortment was shown to be pseudolinkage (78.9 percent recombination). Analyses of joint segregation of triply heterozygous males for the AAT-(1,2) loci and for the single alpha glycerophosphate dehydrogenase locus (AGP-1) revealed true linkage of AGP-1 with one AAT locus (mean r = 11 percent), but pseudolinkage with the other AAT locus (r = 74 percent). Intraindividual variation for homoeologous multivalent pairing of two acrocentric with two metacentric chromosomes in males, but with bivalent pairing in females, is proposed to account for pseudolinkage and for the tetrasomically inherited types.

  1. [Phylogeography of southern Asian Dolly Varden char Salvelinus malma krascheninnikovi: genealogical analysis of mitochondrial DNA]. (United States)

    Oleĭnik, A G; Skurikhina, L A; Chukova, E I


    Phylogeography of southern Asian Dolly Varden char was studied using the data on mtDNA variation (regions ND1/ND2, ND5/ND6, and Cytb/D loop) obtained using PCR-RFLP analysis. Analysis of contemporary population genetic structure showed that S. m. krascheninnikovi throughout the whole species range was characterized by high population differentiation in combination with rather small differences between the populations from remote regions. The genealogy of mtDNA haplotypes was reconstructed and nested clade analysis of geographical distances was performed. Geographical distribution of mtDNA haplotypes of S. m. krascheninnikovi was explained by population genetic processes (restricted gene flow), as well as by historical demographic events (range expansion and fragmentation). It was demonstrated that the main demographic events were associated with cyclic processes of the geological formation of the Sea of Japan and adjacent territories. Furthermore, genealogical tree of S. m. krascheninnikovi contained the traces of secondary contact between isolated phylogeographical lineages.

  2. Movement patterns and spatial segregation of two populations of lake trout Salvelinus namaycush in Lake Huron (United States)

    Binder, Thomas; Marsden, J. Ellen; Riley, Stephen; Johnson, James E.; Johnson, Nicholas; He, Ji; Ebener, Mark P.; Holbrook, Christopher; Bergstedt, Roger A.; Bronte, Charles R.; Hayden, Todd A.; Krueger, Charles C.


    Movement ecology is an important component of life history and population dynamics, and consequently its understanding can inform successful fishery management decision-making. While lake trout populations in Lake Huron have shown signs of recovery from near extinction in recent years, knowledge of their movement behavior remains incomplete. We used acoustic telemetry to describe and compare movement patterns of two Lake Huron lake trout populations: Drummond Island and Thunder Bay. Both populations showed high spawning site fidelity, with no evidence of co-mingling during non-spawning season. Detections between spawning periods were mainly limited to receivers within 100 km of spawning locations, and suggested that the two populations likely remained segregated throughout the year. Drummond Island fish, which spawn inside the Drummond Island Refuge, primarily dispersed east into Canadian waters of Lake Huron, with 79–92% of fish being detected annually on receivers outside the refuge. In contrast, Thunder Bay fish tended to disperse south towards Saginaw Bay. Large proportions (i.e., > 80%) of both populations were available to fisheries outside the management zone containing their spawning location. Thunder Bay fish moved relatively quickly to overwinter habitat after spawning, and tended to repeat the same post-spawning movement behavior each year. The consistent, predictable movement of both populations across management zones highlights the importance of understanding population dynamics to effective management of Lake Huron lake trout.


    Directory of Open Access Journals (Sweden)

    Irena Vardić


    Full Text Available Pathogenic bacterium Renibacterium salmoninarum causes kidney disease with high mortality rate and considerable economic losses in salmonid farming. Thus, application of fast and sensitive method for R. salmoninarum diagnosis is of great importance. This paper describes detection of R. salmoninarum in brook trout tissue with gross clinical signs of disease by nested RT–PCR. Determination of partial sequence of bacterial msa gene was done prior to comparison with similar sequences from different R. salmoninarum isolates. Nested RT–PCR proved to be a rapid and valuable diagnostic tool for R. salmoninarum detection, and sequence analysis confirmed previously reported genetic uniformity of this bacteria

  4. In vitro immune functions in thiamine-replete and -depleted lake trout (Salvelinus namaycush) (United States)

    Ottinger, Christopher A.; Honeyfield, Dale C.; Densmore, Christine L.; Iwanowicz, Luke R.


    In this study we examined the impacts of in vivo thiamine deficiency on lake trout leukocyte function measured in vitro. When compared outside the context of individual-specific thiamine concentrations no significant differences were observed in leukocyte bactericidal activity or in concanavalin A (Con A), and phytohemagglutinin-P (PHA-P) stimulated leukocyte proliferation. Placing immune functions into context with the ratio of in vivo liver thiamine monophosphate (TMP – biologically inactive form) to thiamine pyrophosphate (TPP – biologically active form) proved to be the best indicator of thiamine depletion impacts as determined using regression modeling. These observed relationships indicated differential effects on the immune measures with bactericidal activity exhibiting an inverse relationship with TMP to TPP ratios, Con A stimulated mitogenesis exhibiting a positive relationship with TMP to TPP ratios and PHA-P stimulated mitogenesis exhibiting no significant relationships. In addition, these relationships showed considerable complexity which included the consistent observation of a thiamine-replete subgroup with characteristics similar to those seen in the leukocytes from thiamine-depleted fish. When considered together, our observations indicate that lake trout leukocytes experience cell-type specific impacts as well as an altered physiologic environment when confronted with a thiamine-limited state.

  5. Erythrocyte heat shock protein responses to chronic (in vivo) and acute (in vitro) temperature challenge in diploid and triploid salmonids. (United States)

    Saranyan, Pillai V; Ross, Neil W; Benfey, Tillmann J


    This research investigated how ploidy level (diploid versus triploid) affects the heat shock protein (HSP) response in erythrocytes under different thermal stress regimes, both in vivo and in vitro, in Atlantic salmon (Salmo salar) and brook charr (Salvelinus fontinalis) in order to address the question of why triploids typically have reduced thermal tolerance. A preliminary study confirmed that identical volumes of diploid and triploid erythrocytes (which equates to a smaller number of larger cells for triploids compared to diploids) did not differ in total protein synthesis rates. After chronic (100d) acclimation of fish to 5, 15 and 25°C, triploid erythrocytes had lower HSP70, HSP90, heat shock factor 1 (HSF1) and ubiquitin (free and total) levels than diploids in both species. Furthermore, Atlantic salmon erythrocytes showed significantly higher protein breakdown (based on conjugated ubiquitin levels) in triploids than diploids after acute heat stress in vitro, but no significant difference was detected between ploidies after acute cold stress. These results indicate that: 1) triploid erythrocytes synthesize more total protein per cell than diploids as a result of increased cell size; 2) triploids have sufficient total HSP levels for survival under low stress conditions; and 3) the lower basal titres of HSPs in triploids may be a handicap when combating acute stress. Taken together, this suggests that triploids are limited in their ability to withstand thermal stress because of a reduced ability to maintain proteostasis under stressful conditions.

  6. Toxaphene in the aquatic environment of Greenland. (United States)

    Vorkamp, Katrin; Rigét, Frank F; Dietz, Rune


    The octa- and nonachlorinated bornanes (toxaphene) CHBs 26, 40, 41, 44, 50 and 62 were analysed in Arctic char (Salvelinus alpinus), shorthorn sculpin (Myoxocephalus scorpius), ringed seal (Pusa hispida) and black guillemot eggs (Cepphus grylle) from Greenland. Despite their high trophic level, ringed seals had the lowest concentrations of these species, with a Σ6Toxaphene median concentration of 13-20 ng/g lipid weight (lw), suggesting metabolisation. The congener composition also suggests transformation of nona- to octachlorinated congeners. Black guillemot eggs had the highest concentrations (Σ6Toxaphene median concentration of 971 ng/g lw). Although concentrations were higher in East than in West Greenland differences were smaller than for other persistent organic pollutants. In a circumpolar context, toxaphene had the highest concentrations in the Canadian Arctic. Time trend analyses showed significant decreases for black guillemot eggs and juvenile ringed seals, with annual rates of -5 to -7% for Σ6Toxaphene. The decreases were generally steepest for CHBs 40, 41 and 44.

  7. Diplostomum von Nordmann, 1832 (Digenea: Diplostomidae) in the sub-Arctic: descriptions of the larval stages of six species discovered recently in Iceland. (United States)

    Faltýnková, Anna; Georgieva, Simona; Kostadinova, Aneta; Blasco-Costa, Isabel; Scholz, Tomáš; Skírnisson, Karl


    Frequent infections with Diplostomum spp. (Digenea: Diplostomidae) were found in the freshwater snail Radix peregra (Müller) and three fish species, the salmonids Salmo trutta fario L., Salvelinus alpinus (L.) and the gasterosteid Gasterosteus aculeatus L., collected in four lakes in south-western Iceland in 2012. Detailed analysis of the isolates integrating molecular, morphological and ecological data revealed that these belong to Diplostomum spathaceum (Rudolphi, 1819) and five putative new species (three infecting both snails and fish). This paper provides detailed descriptions of the metacercariae of the six species-level lineages of Diplostomum spp. and of the cercariae of three of the lineages discovered in Iceland with comments on the application of ITS1 rDNA for species distinction within Diplostomum von Nordmann, 1832 in the light of the novel data. We strongly suggest the use of molecular evidence based on cox1 gene sequences (in addition to ITS1-5.8S-ITS2 sequences) in association with detailed assessment of the morphology of the larval stages in future studies of Diplostomum spp. in fish and snails.

  8. Modelling turnover of Cs-137 in two subarctic salmonid ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Nordlinder, S.; Bergstroem, U. (Studsvik AB, Ecosafe, Nykoeping (Sweden)); Hammar, J. (Institute of Freshwater Research, Drottningholm (Sweden) Uppsala Univ. (Sweden). Dept. of Zoology); Notter, M. (Swedish Environmental Protection Agency, Solna (Sweden))


    The turnover of cesium-137 was simulated in two categories of subarctic, alpine lake ecosystems - a natural lake with Gammarus lacustris as major fish prey and a lake reservoir with introduced Mysis relicta as a new fish-food organism. The resulting concentrations of Cs-137 in two salmonid species - Arctic char (Salvelinus alpinus) and brown trout (Salmo trutta) - were calculated using a multi-compartment model. Observed data were taken from a major case study evaluating the distribution, pathways and major transport mechanisms of Chernobyl cesium through northern lake ecosystems in 1986-90. The aim of this study was to design a specific conceptual model for calculation of the levels of Cs-137 in fish from simple lake ecosystems, which could be adopted for other more complex types of lakes. A multi-compartment model of the ecosystem was designed and the equations were solved with the BIOPATH-code. The uncertainty of the results due to the uncertainty of input values was examined using the PRISM-system. The model gave good correlations to measured data for Cs-137 in water, zooplankton, macro invertebrates and fish in both lakes. The predicted levels in sediments were, however, considerably lower than the observed values. The inflow of Cs-137 from the drainage area to the two lakes was identified as the main contributor to the uncertainty of the long-term prognoses. 33 refs, 6 figs, 3 tabs.

  9. Stunning fish with CO2 or electricity: contradictory results on behavioural and physiological stress responses. (United States)

    Gräns, A; Niklasson, L; Sandblom, E; Sundell, K; Algers, B; Berg, C; Lundh, T; Axelsson, M; Sundh, H; Kiessling, A


    Studies that address fish welfare before slaughter have concluded that many of the traditional systems used to stun fish including CO2 narcosis are unacceptable as they cause avoidable stress before death. One system recommended as a better alternative is electrical stunning, however, the welfare aspects of this method are not yet fully understood. To assess welfare in aquaculture both behavioural and physiological measurements have been used, but few studies have examined the relationship between these variables. In an on-site study aversive behaviours and several physiological stress indicators, including plasma levels of cortisol and ions as well as blood physiological variables, were compared in Arctic char (Salvelinus alpinus) stunned with CO2 or electricity. Exposure to water saturated with CO2 triggered aversive struggling and escape responses for several minutes before immobilization, whereas in fish exposed to an electric current immobilization was close to instant. On average, it took 5 min for the fish to recover from electrical stunning, whereas fish stunned with CO2 did not recover. Despite this, the electrically stunned fish had more than double the plasma levels of cortisol compared with fish stunned with CO2. This result is surprising considering that the behavioural reactions were much more pronounced following CO2 exposure. These contradictory results are discussed with regard to animal welfare and stress physiological responses. The present results emphasise the importance of using an integrative and interdisciplinary approach and to include both behavioural and physiological stress indicators in order to make accurate welfare assessments of fish in aquaculture.

  10. Consistency in trophic magnification factors of cyclic methyl siloxanes in pelagic freshwater food webs leading to brown trout. (United States)

    Borgå, Katrine; Fjeld, Eirik; Kierkegaard, Amelie; McLachlan, Michael S


    Cyclic volatile methyl siloxanes (cVMS) concentrations were analyzed in the pelagic food web of two Norwegian lakes (Mjøsa, Randsfjorden), and in brown trout (Salmo trutta) and Arctic char (Salvelinus alpinus) collected in a reference lake (Femunden), in 2012. Lakes receiving discharge from wastewater treatment plants (Mjøsa and Randsfjorden) had cVMS concentrations in trout that were up to 2 orders of magnitude higher than those in Femunden, where most samples were close to the limit of quantification (LOQ). Food web biomagnification of cVMS in Mjøsa and Randsfjorden was quantified by estimation of trophic magnification factors (TMFs). TMF for legacy persistent organic pollutants (POPs) were analyzed for comparison. Both decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) biomagnified with TMFs of 2.9 (2.1-4.0) and 2.3 (1.8-3.0), respectively. Octamethylcyclotetrasiloxane (D4) was below the LOQ in the majority of samples and had substantially lower biomagnification than for D5 and D6. The cVMS TMFs did not differ between the lakes, whereas the legacy POP TMFs were higher in Mjøsa than inRandsfjorden. Whitefish had lower cVMS bioaccumulation compared to legacy POPs, and affected the TMF significance for cVMS, but not for POPs. TMFs of D5 and legacy contaminants in Lake Mjøsa were consistent with those previously measured in Mjøsa.

  11. The effects of inbreeding on sperm quality traits in captive‐bred lake trout, Salvelinus namaycush (Walbaum, 1972)

    DEFF Research Database (Denmark)

    Johnson, K.; Butts, I. A. E.; Smith, J. L.


    depression in the studied population, due to purging, low levels of inbreeding or lack of detection at the gametic level, or (ii) relaxed selective pressures due to benign hatchery conditions. The present study provides significant insight into the effects of inbreeding on sperm quality in a captive...

  12. Environmental contaminants in brook trout (Salvelinus fontinalis) from Cove Brook and two tributaries of the Sheepscot River (United States)

    US Fish and Wildlife Service, Department of the Interior — The Atlantic salmon (Salmo salar) is a federally-listed endangered species with a Distinct Population Segment (DPS) designated in Maine. In July 2006, thirty-six...

  13. Biomagnification of mercury through lake trout (Salvelinus namaycush) food webs of lakes with different physical, chemical and biological characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Kidd, Karen A., E-mail: [Canadian Rivers Institute and Biology Department, University of New Brunswick, Saint John, NB, Canada E2L 4L5 (Canada); Muir, Derek C.G., E-mail: [Aquatic Contaminants Research Division, Environment Canada, Burlington, ON, Canada L7R 4A6 (Canada); Evans, Marlene S., E-mail: [Aquatic Contaminants Research Division, Environment Canada, Saskatoon, SK, Canada S7N 3H5 (Canada); Wang, Xioawa, E-mail: [Aquatic Contaminants Research Division, Environment Canada, Burlington, ON, Canada L7R 4A6 (Canada); Whittle, Mike [Aquatic Contaminants Research Division, Environment Canada, Burlington, ON, Canada L7R 4A6 (Canada); Swanson, Heidi K., E-mail: [Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9 (Canada); Johnston, Tom, E-mail: [Cooperative Freshwater Ecology Unit, Ontario Ministry of Natural Resources, and Biology Department, Laurentian University, Sudbury, ON, Canada P3E 2C6 (Canada); Guildford, Stephanie, E-mail: [Department of Biology and Large Lakes Observatory, University of Minnesota Duluth, 2205 5th St., Duluth, MN, 55812 (United States)


    Mercury (Hg) biomagnification in aquatic ecosystems remains a concern because this pollutant is known to affect the health of fish-eating wildlife and humans, and the fish themselves. The 'rate' of mercury biomagnification is being assessed more frequently using stable nitrogen isotope ratios ({delta}{sup 15}N), a measure of relative trophic position of biota within a food web. Within food webs and across diverse systems, log-transformed Hg concentrations are significantly and positively related to {delta}{sup 15}N and the slopes of these models vary from one study to another for reasons that are not yet understood. Here we compared the rates of Hg biomagnification in 14 lake trout lakes from three provinces in Canada to understand whether any characteristics of the ecosystems explained this among-system variability. Several fish species, zooplankton and benthic invertebrates were collected from these lakes and analyzed for total Hg (fish only), methyl Hg (invertebrates) and stable isotopes ({delta}{sup 15}N; {delta}{sup 13}C to assess energy sources). Mercury biomagnification rates varied significantly across systems and were higher for food webs of larger (surface area), higher nutrient lakes. However, the slopes were not predictive of among-lake differences in Hg in the lake trout. Results indicate that among-system differences in the rates of Hg biomagnification seen in the literature may be due, in part, to differences in ecosystem characteristics although the mechanisms for this variability are not yet understood. -- Highlights: Black-Right-Pointing-Pointer Mercury biomagnifies through aquatic food webs to toxic levels in top predator fishes. Black-Right-Pointing-Pointer Among-system differences in mercury transfer through food webs occur but have not been explained. Black-Right-Pointing-Pointer Diverse lakes supporting lake trout were compared to understand the ecosystem processes that affect mercury biomagnification. Black-Right-Pointing-Pointer Higher biomagnification of mercury was found in larger, higher nutrient lakes. Black-Right-Pointing-Pointer Results show that the food web processing of mercury is related to ecosystem properties.

  14. Identification of lake trout Salvelinus namaycush spawning habitat in northern Lake Huron using high-resolution satellite imagery (United States)

    Grimm, Amanda G.; Brooks, Colin N.; Binder, Thomas R.; Riley, Stephen C.; Farha, Steve A.; Shuchman, Robert A.; Krueger, Charles C.


    The availability and quality of spawning habitat may limit lake trout recovery in the Great Lakes, but little is known about the location and characteristics of current spawning habitats. Current methods used to identify lake trout spawning locations are time- and labor-intensive and spatially limited. Due to the observation that some lake trout spawning sites are relatively clean of overlaying algae compared to areas not used for spawning, we suspected that spawning sites could be identified using satellite imagery. Satellite imagery collected just before and after the spawning season in 2013 was used to assess whether lake trout spawning habitat could be identified based on its spectral characteristics. Results indicated that Pléiades high-resolution multispectral satellite imagery can be successfully used to estimate algal coverage of substrates and temporal changes in algal coverage, and that models developed from processed imagery can be used to identify potential lake trout spawning sites based on comparison of sites where lake trout eggs were and were not observed after spawning. Satellite imagery is a potential new tool for identifying lake trout spawning habitat at large scales in shallow nearshore areas of the Great Lakes.

  15. Identification of Cryptosporidium Species in Fish from Lake Geneva (Lac Leman in France.

    Directory of Open Access Journals (Sweden)

    Gabriela Certad

    Full Text Available Cryptosporidium, a protozoan parasite that can cause severe diarrhea in a wide range of vertebrates including humans, is increasingly recognized as a parasite of a diverse range of wildlife species. However, little data are available regarding the identification of Cryptosporidium species and genotypes in wild aquatic environments, and more particularly in edible freshwater fish. To evaluate the prevalence of Cryptosporidiumspp. in fish from Lake Geneva (Lac Léman in France, 41 entire fish and 100 fillets (cuts of fish flesh were collected from fishery suppliers around the lake. Nested PCR using degenerate primers followed by sequence analysis was used. Five fish species were identified as potential hosts of Cryptosporidium: Salvelinus alpinus, Esox lucius, Coregonus lavaretus, Perca fluviatilis, and Rutilus rutilus. The presence of Cryptosporidium spp. was found in 15 out of 41 fish (37%, distributed as follows: 13 (87% C. parvum, 1 (7% C. molnari, and 1 (7% mixed infection (C. parvum and C. molnari. C. molnari was identified in the stomach, while C. parvum was found in the stomach and intestine. C. molnari was also detected in 1 out of 100 analyzed fillets. In order to identify Cryptosporidium subtypes, sequencing of the highly polymorphic 60-kDa glycoprotein (gp60 was performed. Among the C. parvum positive samples, three gp60 subtypes were identified: IIaA15G2R1, IIaA16G2R1, and IIaA17G2R1. Histological examination confirmed the presence of potential developmental stages of C. parvum within digestive epithelial cells. These observations suggest that C. parvum is infecting fish, rather than being passively carried. Since C. parvum is a zoonotic species, fish potentially contaminated by the same subtypes found in terrestrial mammals would be an additional source of infection for humans and animals, and may also contribute to the contamination of the environment with this parasite. Moreover, the risk of human transmission is strengthened by

  16. Identification of Cryptosporidium Species in Fish from Lake Geneva (Lac Léman) in France. (United States)

    Certad, Gabriela; Dupouy-Camet, Jean; Gantois, Nausicaa; Hammouma-Ghelboun, Ourida; Pottier, Muriel; Guyot, Karine; Benamrouz, Sadia; Osman, Marwan; Delaire, Baptiste; Creusy, Colette; Viscogliosi, Eric; Dei-Cas, Eduardo; Aliouat-Denis, Cecile Marie; Follet, Jérôme


    Cryptosporidium, a protozoan parasite that can cause severe diarrhea in a wide range of vertebrates including humans, is increasingly recognized as a parasite of a diverse range of wildlife species. However, little data are available regarding the identification of Cryptosporidium species and genotypes in wild aquatic environments, and more particularly in edible freshwater fish. To evaluate the prevalence of Cryptosporidiumspp. in fish from Lake Geneva (Lac Léman) in France, 41 entire fish and 100 fillets (cuts of fish flesh) were collected from fishery suppliers around the lake. Nested PCR using degenerate primers followed by sequence analysis was used. Five fish species were identified as potential hosts of Cryptosporidium: Salvelinus alpinus, Esox lucius, Coregonus lavaretus, Perca fluviatilis, and Rutilus rutilus. The presence of Cryptosporidium spp. was found in 15 out of 41 fish (37%), distributed as follows: 13 (87%) C. parvum, 1 (7%) C. molnari, and 1 (7%) mixed infection (C. parvum and C. molnari). C. molnari was identified in the stomach, while C. parvum was found in the stomach and intestine. C. molnari was also detected in 1 out of 100 analyzed fillets. In order to identify Cryptosporidium subtypes, sequencing of the highly polymorphic 60-kDa glycoprotein (gp60) was performed. Among the C. parvum positive samples, three gp60 subtypes were identified: IIaA15G2R1, IIaA16G2R1, and IIaA17G2R1. Histological examination confirmed the presence of potential developmental stages of C. parvum within digestive epithelial cells. These observations suggest that C. parvum is infecting fish, rather than being passively carried. Since C. parvum is a zoonotic species, fish potentially contaminated by the same subtypes found in terrestrial mammals would be an additional source of infection for humans and animals, and may also contribute to the contamination of the environment with this parasite. Moreover, the risk of human transmission is strengthened by the

  17. Identification of Cryptosporidium Species in Fish from Lake Geneva (Lac Léman) in France (United States)

    Certad, Gabriela; Dupouy-Camet, Jean; Gantois, Nausicaa; Hammouma-Ghelboun, Ourida; Pottier, Muriel; Guyot, Karine; Benamrouz, Sadia; Osman, Marwan; Delaire, Baptiste; Creusy, Colette; Viscogliosi, Eric; Aliouat-Denis, Cecile Marie; Follet, Jérôme


    Cryptosporidium, a protozoan parasite that can cause severe diarrhea in a wide range of vertebrates including humans, is increasingly recognized as a parasite of a diverse range of wildlife species. However, little data are available regarding the identification of Cryptosporidium species and genotypes in wild aquatic environments, and more particularly in edible freshwater fish. To evaluate the prevalence of Cryptosporidiumspp. in fish from Lake Geneva (Lac Léman) in France, 41 entire fish and 100 fillets (cuts of fish flesh) were collected from fishery suppliers around the lake. Nested PCR using degenerate primers followed by sequence analysis was used. Five fish species were identified as potential hosts of Cryptosporidium: Salvelinus alpinus, Esox lucius, Coregonus lavaretus, Perca fluviatilis, and Rutilus rutilus. The presence of Cryptosporidium spp. was found in 15 out of 41 fish (37%), distributed as follows: 13 (87%) C. parvum, 1 (7%) C. molnari, and 1 (7%) mixed infection (C. parvum and C. molnari). C. molnari was identified in the stomach, while C. parvum was found in the stomach and intestine. C. molnari was also detected in 1 out of 100 analyzed fillets. In order to identify Cryptosporidium subtypes, sequencing of the highly polymorphic 60-kDa glycoprotein (gp60) was performed. Among the C. parvum positive samples, three gp60 subtypes were identified: IIaA15G2R1, IIaA16G2R1, and IIaA17G2R1. Histological examination confirmed the presence of potential developmental stages of C. parvum within digestive epithelial cells. These observations suggest that C. parvum is infecting fish, rather than being passively carried. Since C. parvum is a zoonotic species, fish potentially contaminated by the same subtypes found in terrestrial mammals would be an additional source of infection for humans and animals, and may also contribute to the contamination of the environment with this parasite. Moreover, the risk of human transmission is strengthened by the

  18. Cesium in Arctic char lakes - effects of the Chernobyl accident. Radioaktivt cesium i roedingsjoear - effekter av Tjernobylkatastrofen

    Energy Technology Data Exchange (ETDEWEB)

    Hammar, J. (Fiskeriverkets Soetvattenslaboratorium, Drottningholm (Sweden)); Notter, M.; Neumann, G. (Statens Naturvaardesverks Miljoekontrollaboratorium, Drottningholm (Sweden))


    Fallout radiocesium from the Chernobyl accident caused extensive contamination in a region of previously well studied alpine lake ecosystems in northern Sweden. Levels of Cs-137 in the barren catchment basins reached 20-50 kBq/m[sup 2] during 1986. The distribution, pathways and major transport mechanisms of radiocesium through the lake ecosystems were studied during 1986-1990. Levels of Cs-137, Cs-134 and K-40 in water, surface sediment, detritus (sediment traps) and different trophic levels of the food chains of Arctic char (Salvelinus alpinus) and brown trout (Salmo trutta) were monitored in a series of lakes forming a matrix of 4 natural lakes and 3 lake reservoirs, with or without the introduced new fish food organism, Mysis relicta. The reservoirs were found to act as sinks for radiocesium with extensive accumulation recorded in water, detritus, sediment, invertebrates and salmonids. Whereas concentrations in water and biota have declined from the extreme peak levels in 1986-1987, the levels in surface sediment increased extensively until fall of 1988. The concentration of Cs-137 in fish populations feeding on benthic invertebrates, i.e. mysids and amphipods, were significantly higher than in planktivorous fish. During the three first winters a significant increase in levels of Cs-137 in winter active Arctic char were recorded, whereas the levels declined during the succeeding summers. The introduced Mysis relicta were found to enhance the transport of Cs-137 from zooplankton and settling particles to Arctic char and brown trout. The results suggest a successive change in transport of radiocesium from water via zooplankton to planktivorous fish during the early summer of 1986 to post-depositional mobilization via benthic organisms to benthic fish in successive years. (213 refs.) (au).

  19. Enantiomer-specific biomagnification of alpha-hexachlorocyclohexane and selected chiral chlordane-related compounds within an Arctic marine food web. (United States)

    Hoekstra, Paul F; O'Hara, Todd M; Karlsson, Heidi; Solomon, Keith R; Muir, Derek C


    Concentrations of achiral and chiral organochlorine contaminants (OCs), including hexachlorocyclohexane isomers (HCH), chlordane congeners (cis- and trans-chlordane, cis- and trans-nonachlor, MC5, MC7, and U82), and related metabolites (oxychlordane [OXY] and heptachlor exo-epoxide [HEPX]), were quantified in seawater (100 L; n = 6) and biota from the coastal Beaufort-Chukchi Seas food web near Barrow (AK, USA). The biota included zooplankton (Calanus spp.; n = 5), fish species such as arctic cod (Boreogadus saida; n = 10), arctic char (Salvelinus alpinus; n = 3), and marine mammals including bowhead whales (Balaena mysticetus; liver: n = 23; blubber: n = 40), beluga whales (Delphinapterus leucas; blubber: n = 20), ringed seals (Phoca hispida; blubber: n = 20), and bearded seals (Erignathus barbatus; blubber: n = 7). The food web magnification factors (FWMFs) for HCHs and chlordane compounds ranged from 0.5 (gamma-HCH) to 6.5 (HEPX) and were expected based on known recalcitrance and biotransformation of OCs. The enantiomer fractions (EFs) of all chiral OCs were near racemic (EF = 0.50) in the seawater, zooplankton, and all fish analyzed. In contrast, the EFs for most OCs analyzed were nonracemic (EF # 0.50) in the marine mammals blubber (range: 0.09-0.79) because of enantiomer-specific biotransformation and (or) accumulation. However, EF values were not significantly correlated with isotopically determined trophic level. The EFs for all chiral OCs (except alpha-HCH) in bowhead whale liver closely approximated the values in zooplankton, suggesting that the accumulation of chiral OCs from prey into this cetacean is not enantiomer specific. However, the modification of EFs from bowhead liver to blubber suggests that this species has the ability to enantioselectively biotransform and accumulate several chiral OC compounds.

  20. Persistent organic pollutants in biota samples collected during the Ymer-80 expedition to the Arctic

    Directory of Open Access Journals (Sweden)

    Henrik Kylin


    Full Text Available During the 1980 expedition to the Arctic with the icebreaker Ymer, a number of vertebrate species were sampled for determination of persistent organic pollutants. Samples of Arctic char (Salvelinus alpinus, n=34, glaucous gull (Larus hyperboreus, n=8, common eider (Somateria mollissima, n=10, Brünnich's guillemot (Uria lomvia, n=9, ringed seal (Pusa hispida, n=2 and polar bear (Ursus maritimus, n=2 were collected. With the exception of Brünnich's guillemot, there was a marked contamination difference of birds from western as compared to eastern/northern Svalbard. Samples in the west contained a larger number of polychlorinated biphenyl (PCB congeners and also polychlorinated terphenyls, indicating local sources. Brünnich's guillemots had similar pollutant concentrations in the west and east/north; possibly younger birds were sampled in the west. In Arctic char, pollutant profiles from lake Linnévatn (n=5, the lake closest to the main economic activities in Svalbard, were similar to profiles in Arctic char from the Shetland Islands (n=5, but differed from lakes to the north and east in Svalbard (n=30. Arctic char samples had higher concentrations of hexachlorocyclohexanes (HCHs than the marine species of birds and mammals, possibly due to accumulation via snowmelt. Compared to the Baltic Sea, comparable species collected in Svalbard had lower concentrations of PCB and dichlorodiphenyltrichloroethane (DDT, but similar concentrations indicating long-range transport of hexachlorobenzene, HCHs and cyclodiene pesticides. In samples collected in Svalbard in 1971, the concentrations of PCB and DDT in Brünnich's guillemot (n=7, glaucous gull (n=2 and polar bear (n=2 were similar to the concentrations found in 1980.

  1. Preference for cannibalism and ontogenetic constraints in competitive ability of piscivorous top predators. (United States)

    Byström, Pär; Ask, Per; Andersson, Jens; Persson, Lennart


    Occurrence of cannibalism and inferior competitive ability of predators compared to their prey have been suggested to promote coexistence in size-structured intraguild predation (IGP) systems. The intrinsic size-structure of fish provides the necessary prerequisites to test whether the above mechanisms are general features of species interactions in fish communities where IGP is common. We first experimentally tested whether Arctic char (Salvelinus alpinus) were more efficient as a cannibal than as an interspecific predator on the prey fish ninespine stickleback (Pungitius pungitius) and whether ninespine stickleback were a more efficient competitor on the shared zooplankton prey than its predator, Arctic char. Secondly, we performed a literature survey to evaluate if piscivores in general are more efficient as cannibals than as interspecific predators and whether piscivores are inferior competitors on shared resources compared to their prey fish species. Both controlled pool experiments and outdoor pond experiments showed that char imposed a higher mortality on YOY char than on ninespine sticklebacks, suggesting that piscivorous char is a more efficient cannibal than interspecific predator. Estimates of size dependent attack rates on zooplankton further showed a consistently higher attack rate of ninespine sticklebacks compared to similar sized char on zooplankton, suggesting that ninespine stickleback is a more efficient competitor than char on zooplankton resources. The literature survey showed that piscivorous top consumers generally selected conspecifics over interspecific prey, and that prey species are competitively superior compared to juvenile piscivorous species in the zooplankton niche. We suggest that the observed selectivity for cannibal prey over interspecific prey and the competitive advantage of prey species over juvenile piscivores are common features in fish communities and that the observed selectivity for cannibalism over interspecific prey has

  2. Understanding how lake populations of arctic char are structured and function with special consideration of the potential effects of climate change: a multi-faceted approach. (United States)

    Budy, Phaedra; Luecke, Chris


    Size dimorphism in fish populations, both its causes and consequences, has been an area of considerable focus; however, uncertainty remains whether size dimorphism is dynamic or stabilizing and about the role of exogenous factors. Here, we explored patterns among empirical vital rates, population structure, abundance and trend, and predicted the effects of climate change on populations of arctic char (Salvelinus alpinus) in two lakes. Both populations cycle dramatically between dominance by small (≤300 mm) and large (>300 mm) char. Apparent survival (Φ) and specific growth rates (SGR) were relatively high (40-96%; SGR range 0.03-1.5%) and comparable to those of conspecifics at lower latitudes. Climate change scenarios mimicked observed patterns of warming and resulted in temperatures closer to optimal for char growth (15.15 °C) and a longer growing season. An increase in consumption rates (28-34%) under climate change scenarios led to much greater growth rates (23-34%). Higher growth rates predicted under climate change resulted in an even greater predicted amplitude of cycles in population structure as well as an increase in reproductive output (Ro) and decrease in generation time (Go). Collectively, these results indicate arctic char populations (not just individuals) are extremely sensitive to small changes in the number of ice-free days. We hypothesize years with a longer growing season, predicted to occur more often under climate change, produce elevated growth rates of small char and act in a manner similar to a "resource pulse," allowing a sub-set of small char to "break through," thus setting the cycle in population structure.

  3. Population connectivity: dam migration mitigations and contemporary site fidelity in arctic char

    Directory of Open Access Journals (Sweden)

    Heggenes Jan


    Full Text Available Abstract Background Animal feeding and spawning migrations may be limited by physical barriers and behavioral interactions. Dam constructions (e.g. hydropower commonly include gateways for fish migrations to sustain ecological connectivity. Relative genetic impacts of fish passage devices versus natural processes (e.g. hybrid inferiority are, however, rarely studied. We examined genetic (i.e. microsatellite population connectivity of highly migrating lake-dwelling Arctic char (Salvelinus alpinus, introduced 20 generations ago, across and within two subalpine lakes separated by a dam with a subterranean tunnel and spill gates after 7 generations. Due to water flow regime, the time window for fish migration is highly restricted. Results Char populations, with similar genetic structuring and diversity observed across and within lakes, were admixed across the dam with fishways during feeding. For spawning, however, statistically significant, but very low population differentiation (θ; 0.002 - 0.013 was found in nine out of ten reproductive site comparisons, reflecting interactions between extensive migration (mean first generation (F0 = 10.8% and initial site fidelity. Simulations indicated that genetic drift among relatively small effective populations (mean Ne = 62 may have caused the observed contemporary differentiation. Novel Bayesian analyses indicated mean contributions of 71% F0 population hybrids in spawning populations, of which 76% had maternal or paternal native origin. Conclusions Ecological connectivity between lakes separated by a dam has been retained through construction of fishways for feeding migration. Considerable survival and homing to ancestral spawning sites in hybrid progeny was documented. Population differentiation despite preceding admixture is likely caused by contemporary reduced reproductive fitness of population hybrids. The study documents the beginning stages of population divergence among spatial aggregations with

  4. 78 FR 12777 - Endangered Species; Marine Mammals; Receipt of Applications for Permit (United States)


    ... Cheetah (Acinonyx jubatus) to Canada for the purpose of enhancement of the species through scientific... peninsularis) Cheetah (Acinonyx jubatus) African wild dog (Lycaon pictus) Dhole (Cuon alpinus)...

  5. Mixed-function oxidase enzyme activity and oxidative stress in lake trout (Salvelinus namaycush) exposed to 3,3{prime},4,4{prime}5-pentachlorobiphenyl (PCB-126)

    Energy Technology Data Exchange (ETDEWEB)

    Palace, V.P. [Univ. of Manitoba, Winnipeg, Manitoba (Canada). Dept. of Zoology; Klaverkamp, J.F.; Lockhart, W.L. [Univ. of Manitoba, Winnipeg, Manitoba (Canada). Dept. of Zoology]|[Department of Fisheries and Oceans, Winnipeg, Manitoba (Canada). Freshwater Inst.; Metner, D.A.; Muir, D.C.G.; Brown, S.B. [Department of Fisheries and Oceans, Winnipeg, Manitoba (Canada). Freshwater Inst.


    Juvenile lake trout were intraperitoneally injected with corn oil containing nominal concentrations of 0, 0.6, 6.3, or 25 {micro}g [{sup 14}C]-3,3{prime},4,4{prime},5-pentachlorobiphenyl (PCB-126) per gram of body weight. The PCB-126 accumulated in liver in a dose-dependent manner to a sustained concentration by 6 weeks and remained elevated for the 30-week experimental period. Mixed-function oxidase (MFO) enzyme activity was elevated in the two highest dose groups relative to the control group, but not in the low-dose group throughout the 30 weeks. Oxidative stress, measured by the thiobarbituric acid reactive substances test, was correlated with ethoxyresorufin O-deethylase and was elevated in liver of the two highest PCB dose groups but not the low-dose group. The activities of the enzymatic antioxidants superoxide dismutase, catalase, and glutathione peroxidase were unaffected by PCB-126 exposure. The nonenzymatic antioxidants superoxide dismutase, catalase, and glutathione peroxidase were unaffected by PCB-126 exposure. The nonenzymatic antioxidant tocopherol was depleted to approximately 75% of the control concentration in liver of all three PCB-dosed groups. Hepatic ascorbic acid levels were not different in any of the treatment groups. Retinol was depleted by greater than an order of magnitude in liver of the two highest dose groups but not in the los-dose group. This study demonstrates a correlation between hepatic MFO activity and oxidative stress in PCB-exposed lake trout. Tocopherol and retinol may be important mediators of oxidative stress but additional study is required to confirm the antioxidant activity of retinol.

  6. On the rate of decline of persistent organic contaminants in lake trout (Salvelinus namaycush) from the Great Lakes, 1970-2003. (United States)

    Carlson, Daniel L; De Vault, David S; Swackhamer, Deborah L


    Thirty-four years of data from the Great Lakes Fish Monitoring Program (GLFMP) show significant changes in the behavior of most contaminants in lake trout over time consistent with changes in contaminant inputs following regulation and remediation. Polybrominated diphenyl ethers (PBDEs) show positive apparent first-order rate constants falling to near zero. Dieldrin shows relatively unchanging half-lives of around 10 years except in Lake Superior (approximately 25 years). Mirex, consistently detected only in Lake Ontario fish, shows a slow decrease until the 1990s, when remediation of a source site occurred, after which half-lives are 2-3 years. Half-lives of oxychlordane, polychlorinated biphenyls (PCBs), and dichloro-diphenyl-trichlorethane (DDT) and its metabolites were typically 3-6 years until the mid 1980s; since then, the newest data confirm half-lives are usually around 15-30 years. For PCBs, an increasing half-life is found in other media as well. Changes in food web structure, fishery dynamics, and climate undoubtedly affect concentrations but cannot explain observed long-term trends across several media. Concentrations of legacy contaminants in the Great Lakes are likely to continue to decline only slowly and pose a health concern for decades without identifying and containing remaining sources.

  7. [Variation of the mitochondrial DNA control region in the populations of southern form of Dolly Varden (Salvelinus malma krascheninnikovi) from Sakhalin]. (United States)

    Osinov, A G; Miuge, N S


    Analysis of a 551-bp segment of the mitochondrial DNA control region in 23 individuals from nine populations of Dolly Varden from Sakhalin and three individuals from the Shikaribetsu Lake (Hokkaido) revealed the presence of seven haplotypes of southern form, along with one haplotype of northern form of Dolly Varden. All seven haplotypes of southern Dolly Varden were earlier described in the populations from Hokkaido. Nested analysis of molecular variance (AMOVA) based on the haplotype frequencies, performed using literature data, suggested that, during the glacial epoch, there were three regional population groups of Dolly Varden (from eastern and western coasts of Sakhalin, and from Southern Primorye). Population groups from Sakhalin and Primorye were clearly separated. The differences between two Sakhalin population groups in the mtDNA haplotype frequencies were not statistically significant. However, relative to the earlier obtained data on microsatellite loci, these differences were statistically significant. For the populations of Sakhalin Dolly Varden, the data on mitochondrial and microsatellite DNA variation supplement each other.

  8. The effects of low-speed swimming following exhaustive exercise on metabolic recovery and swimming performance in brook trout (Salvelinus fontinalis). (United States)

    Kieffer, James D; Kassie, Roshini S; Taylor, Susan G


    Experiments were conducted to determine whether low-speed swimming during recovery from exhaustive exercise improved both metabolic recovery and performance during a swimming challenge. For these experiments, brook trout were allowed to recover from exhaustive exercise for 2 h while swimming at 0, 0.5, 1.0, or 1.5 body length (BL) s(-1) or allowed to recover from exhaustive exercise for 1, 2, or 3 h while swimming at 1.0 BL s(-1). At the appropriate interval, either (i) muscle and blood samples were removed from the fish or (ii) fish were assessed for performance (i.e., fatigue time) during a fixed-interval swimming test. Low-speed swimming during recovery from exhaustive exercise resulted in significantly longer fatigue times compared with fish recovering in still water (i.e., 0 BL s(-1)). However, swimming during recovery did not expedite recovery of muscle lactate or blood variables (e.g., lactate, osmolarity, glucose). These observations suggest that metabolic recovery and subsequent swimming performance may not be directly linked and that other factors play a role in swimming recovery in brook trout.

  9. Evidence of climate-induced range contractions in bull trout Salvelinus confluentus in a Rocky Mountain watershed, U.S.A.

    Directory of Open Access Journals (Sweden)

    Lisa A Eby

    Full Text Available Many freshwater fish species are considered vulnerable to stream temperature warming associated with climate change because they are ectothermic, yet there are surprisingly few studies documenting changes in distributions. Streams and rivers in the U.S. Rocky Mountains have been warming for several decades. At the same time these systems have been experiencing an increase in the severity and frequency of wildfires, which often results in habitat changes including increased water temperatures. We resampled 74 sites across a Rocky Mountain watershed 17 to 20 years after initial samples to determine whether there were trends in bull trout occurrence associated with temperature, wildfire, or other habitat variables. We found that site abandonment probabilities (0.36 were significantly higher than colonization probabilities (0.13, which indicated a reduction in the number of occupied sites. Site abandonment probabilities were greater at low elevations with warm temperatures. Other covariates, such as the presence of wildfire, nonnative brook trout, proximity to areas with many adults, and various stream habitat descriptors, were not associated with changes in probability of occupancy. Higher abandonment probabilities at low elevation for bull trout provide initial evidence validating the predictions made by bioclimatic models that bull trout populations will retreat to higher, cooler thermal refuges as water temperatures increase. The geographic breadth of these declines across the region is unknown but the approach of revisiting historical sites using an occupancy framework provides a useful template for additional assessments.

  10. A salmonid EST genomic study: genes, duplications, phylogeny and microarrays

    Directory of Open Access Journals (Sweden)

    Brahmbhatt Sonal


    Full Text Available Abstract Background Salmonids are of interest because of their relatively recent genome duplication, and their extensive use in wild fisheries and aquaculture. A comprehensive gene list and a comparison of genes in some of the different species provide valuable genomic information for one of the most widely studied groups of fish. Results 298,304 expressed sequence tags (ESTs from Atlantic salmon (69% of the total, 11,664 chinook, 10,813 sockeye, 10,051 brook trout, 10,975 grayling, 8,630 lake whitefish, and 3,624 northern pike ESTs were obtained in this study and have been deposited into the public databases. Contigs were built and putative full-length Atlantic salmon clones have been identified. A database containing ESTs, assemblies, consensus sequences, open reading frames, gene predictions and putative annotation is available. The overall similarity between Atlantic salmon ESTs and those of rainbow trout, chinook, sockeye, brook trout, grayling, lake whitefish, northern pike and rainbow smelt is 93.4, 94.2, 94.6, 94.4, 92.5, 91.7, 89.6, and 86.2% respectively. An analysis of 78 transcript sets show Salmo as a sister group to Oncorhynchus and Salvelinus within Salmoninae, and Thymallinae as a sister group to Salmoninae and Coregoninae within Salmonidae. Extensive gene duplication is consistent with a genome duplication in the common ancestor of salmonids. Using all of the available EST data, a new expanded salmonid cDNA microarray of 32,000 features was created. Cross-species hybridizations to this cDNA microarray indicate that this resource will be useful for studies of all 68 salmonid species. Conclusion An extensive collection and analysis of salmonid RNA putative transcripts indicate that Pacific salmon, Atlantic salmon and charr are 94–96% similar while the more distant whitefish, grayling, pike and smelt are 93, 92, 89 and 86% similar to salmon. The salmonid transcriptome reveals a complex history of gene duplication that is


    The in vitro metabolism of phenol at 11 degrees C has been studied using juvenile and immature adult rainbow (Orcorhynchus mykiss), immature adult brook (Salvelinus fontinalis), and immature adult lake trout (Salvelinus namacush) hepatic microsomal preparations.


    In vitro metabolism of phenol at 11 degrees C has been studied using immature adult rainbow (Oncorhynchus mykiss), brook (Salvelinus fontinalis), and lake trout (Salvelinus namaycush) hepatic microsomal preparations. Incubations were optimized for time, cofactor concentration, pH...

  13. Factors affecting biotic mercury concentrations and biomagnification through lake food webs in the Canadian high Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Lescord, Gretchen L., E-mail: [University of New Brunswick/Canadian Rivers Institute, 100 Tucker Park Rd, Saint John, NB E2L 4A6 (Canada); Kidd, Karen A. [University of New Brunswick/Canadian Rivers Institute, 100 Tucker Park Rd, Saint John, NB E2L 4A6 (Canada); Kirk, Jane L. [Environment Canada, Aquatic Contaminants Research Division, 867 Lakeshore Rd, Burlington, ON L7S 1A1 (Canada); O' Driscoll, Nelson J. [Acadia University, 15 University Ave, Wolfville, NS B4P 2R6 (Canada); Wang, Xiaowa; Muir, Derek C.G. [Environment Canada, Aquatic Contaminants Research Division, 867 Lakeshore Rd, Burlington, ON L7S 1A1 (Canada)


    In temperate regions of Canada, mercury (Hg) concentrations in biota and the magnitude of Hg biomagnification through food webs vary between neighboring lakes and are related to water chemistry variables and physical lake features. However, few studies have examined factors affecting the variable Hg concentrations in landlocked Arctic char (Salvelinus alpinus) or the biomagnification of Hg through their food webs. We estimated the food web structure of six high Arctic lakes near Resolute Bay, Nunavut, Canada, using stable carbon (δ{sup 13}C) and nitrogen (δ{sup 15}N) isotopes and measured Hg (total Hg (THg) in char, the only fish species, and methylmercury (MeHg) in chironomids and zooplankton) concentrations in biota collected in 2010 and 2011. Across lakes, δ{sup 13}C showed that benthic carbon (chironomids) was the dominant food source for char. Regression models of log Hg versus δ{sup 15}N (of char and benthic invertebrates) showed positive and significant slopes, indicting Hg biomagnification in all lakes, and higher slopes in some lakes than others. However, no principal components (PC) generated using all water chemistry data and physical characteristics of the lakes predicted the different slopes. The PC dominated by aqueous ions was a negative predictor of MeHg concentrations in chironomids, suggesting that water chemistry affects Hg bioavailability and MeHg concentrations in these lower-trophic-level organisms. Furthermore, regression intercepts were predicted by the PCs dominated by catchment area, aqueous ions, and MeHg. Weaker relationships were also found between THg in small char or MeHg in pelagic invertebrates and the PCs dominated by catchment area, and aqueous nitrate and MeHg. Results from these high Arctic lakes suggest that Hg biomagnification differs between systems and that their physical and chemical characteristics affect Hg concentrations in lower-trophic-level biota. - Highlights: • Mercury (Hg) in Arctic char and invertebrates

  14. Reference: 124 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available at the molecular level about how nitrate is distributed in various plant tissues. In the present study, char...r, atnrt1:4 mutant leaves were wider than wild-type leaves. This study revealed a

  15. Final Environmental Assessment and Finding of No Significant Impact: Deployment of Up to Four F-16C Aircraft to the 133rd Airlift Wing for Air Sovereignty Alert Operations (United States)


    round-stemmed false foxglove Asclepias stenophylla . . . . . . . . . . . . . . . . narrow-leaved milkweed Astragalus alpinus... milkweed Asclepias sullivantii . . . . . . . . . . . . . . . . . Sullivant’s milkweed Asplenium trichomanes . . . . . . . . . . . . . . . maidenhair...clasping milkweed Asplenium platyneuron . . . . . . . . . . . . . . . ebony spleenwort Astragalus flexuosus

  16. The origin of Lotus corniculatus. (United States)

    Ross, M D; Jones, W T


    Earlier students of the origin of Lotus corniculatus suggested that this tetraploid species arose as an autotetraploid of the closely related diploid species L. tenuis or L. alpinus. More recent studies suggested that L. alpinus and L. japonicus could be ancestral forms. The present study of tannin content, phenolic content, cyanide production, morphology, cytogenetics, Rhizobium specificity and self-incompatibility in the corniculatus group virtually excludes the possibility that L. corniculatus could have arisen through autopolyploidy of L. tenuis or L. alpinus, and suggests that L. corniculatus arose through hybridization of L. alpinus and/or L. tenuis (probably as female parent) with L. uliginosus (probably as male parent), followed by chromosome doubling in the hybrid.

  17. An isoenzyme study in the genus Lotus (Fabaceae) : Segregation of isoenzyme alleles in synthetic allo- and autotetraploids, and in L. corniculatus. (United States)

    Raelson, J V; Lemaître, P C; Starkie, K M; Grant, W F


    Segregation of the cytosolic Pgi2 locus was studied among progeny of the synthetic allotetraploid (L. japonicus × L. alpinus)(2), the synthetic autotetraploid (L. alpinus)(2), and the cultivated tetraploid species L. corniculatus L. Evidence of an original diploid duplication found within the interspecific hybrid L. japonicus × L. alpinus was also found within the synthetic allotetraploid (quadruplication of loci). Evidence suggesting quadruplication of loci was also found in the tetraploid L. corniculatus, but not in the synthetic autotetraploid (L. alpinus)(2). It is suggested that the original duplication resulted from unequal crossing-over between homoeologues and that it provides evidence that L. corniculatus is a segmental allotetraploid. Quadruplication of loci in L. corniculatus could explain previously reported distorted tetrasomic ratios for segregation of qualitative characters in this species.

  18. An assessment of the development and survival of wild rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis) exposed to elevated selenium in an area of active coal mining

    Energy Technology Data Exchange (ETDEWEB)

    Holm, J.; Palace, V.P.; Wautier, K.; Evans, R.E.; Baron, C.L.; Podemski, C.; Siwik, P.; Sterling, G.


    Elevated levels of selenium (Se) have recently been detected downstream from uranium and coal mining activity in Canada. While Se is an essential dietary element, elevated concentrations can lead to decreased growth, reproductive impairment and increased mortality. A hallmark of Se toxicity is the appearance of teratogenic deformities in the progeny of exposed females that result from the deposition of Se to their eggs. Teratogenesis is an effective indicator of Se toxicity in fish communities. This study compares three methods of evaluating deformities in the larvae of rainbow trout and brook trout inhabiting seleniferous waters downstream from active coal mining activity in the Northern East Slopes Region of Alberta, Canada. Gametes were stripped from adult fish and transported to the laboratory where they were fertilized and reared to the swim-up stage. Fry were assessed for deformities using frequency analysis, a graduated severity index (GS), and morphometric analysis. Adults show no signs of Se toxicity but accumulated higher concentration of Se in muscle and eggs compared to fish from the reference sites. There were increased incidences of edema and spinal deformities in rainbow trout fry and increased frequency of craniofacial deformities in brook trout fry from the seleniferous site compared to those from the reference sites. Of the three methods used to assess deformities in larval fish, frequency analysis was found to be the most practical, rapid, and produced the most meaningful results.

  19. Notes on Automorphisms of Prime Rings

    Institute of Scientific and Technical Information of China (English)

    Huang Shu-liang; Du Xian-kun


    Let Rbe a prime ring, L a noncentral Lie ideal and σ a nontrivial automorphism of Rsuch that usσ(u)ut = 0 for all u ∈ L, where s, t are fixed non-negative integers. If either charR>s+t or charR=0, then Rsatisfies s4, the standard identity in four variables. We also examine the identity (σ([x, y])−[x, y])n=0 for all x, y∈I, where I is a nonzero ideal of Rand n is a fixed positive integer. If either charR>n or charR=0, then Ris commutative.

  20. 北欧湖泊鱼类状况调查:酸化、富营养化和放养活动对现有鱼类品种组成的影响%Fish Status Survey of Nordic Lakes: Effects of Acidification, Eutrophication and Stocking Activity on Present Fish Species Composition

    Institute of Scientific and Technical Information of China (English)

    JouniTammi; MagnusAppelberg; UlrikaBeier; TrygveHesthagen; AnttiLappalainen; MarttiRask; 李康民; 李佩珍


    1995~1997年间对挪威、瑞典和芬兰的3821个湖泊的鱼类种群状况做了评估。采用分层随机抽样从芬诺斯堪的亚(芬兰,挪威、瑞典,丹麦的总称)所有面积≥0.04km2的126482个湖泊中选择调查湖泊。分析了湖泊的水化学,湖内鱼类状况则从邮件调查问卷中获得。鱼类种群损失发生最为频繁的地区在挪威南部酸化最严重的地区,而在芬诺斯堪的亚东部最少。根据调查问卷,鳟(Salmo trutta)、拟鲤(Rutilus rutilus)、北极红点鲑(Salvelinus alpinus)和鲈鱼(Percafluviatilis)鱼群损失的数量估计超过10000条。这些品种的鱼群潜在地受低碱性湖水影响的数量超过11000条。大约有3300个湖泊显示出总磷高于25μg/L,品种以鲤科鱼为主,这在芬诺斯堪的亚东部、芬兰西南最为明显。这次调查并未显示出鱼类品种由于富营养化而灭绝。l/3的湖泊人工放养了至少一个新的鱼类品种,最常放养的品种有鳟、白鲑(Coregonus lavaretus s.l.)、北极红点鲑、虹鳟(Oncorhynchus mykiss)、梭鲈(Stizostedion lucioperca)、茴鱼(Thymallus thymallus)、狗鱼(Esox lucius)、欧鳊(Abramis brama)、丁秽(Tinca tinca)和欧Gui(Tinca tinca)和欧Gui(Phoxinus phoxinus)。在芬诺斯堪的亚湖泊。这些品种的人工放养量估计超过52000群,因此,北欧湖泊现有鱼类品种的数量最近受放养的影响超过了因环境变化如酸化等而损失造成的影响。

  1. An Inventory of the Vascular Flora of Fort Greely, Interior Alaska (United States)


    balsamifera Populus tremuloides Michx. Potamogeton alpinus Balbis Potamogeton filiformis Pers. *Potamogeton foliosus Raf. Potamogeton gramineus L...P. Mill. ssp. multifida (Pritz.) Zamels Pyrola asarifolia Michx. Pyrola chlorantha Sw. Pyrola grandiflora Radius *Pyrola minor L. Ranunculus gmelini...DC. ssp. gmelini 26 Ranunculus hyperboreus Rottb. Ranunculus lapponicus L. * Ranunculus nivalis L. Ranunculus reptans L. Ranunculus sceleratus L. ssp

  2. 76 FR 2408 - Endangered Species; Marine Mammals; Receipt of Applications for Permit (United States)


    ... guarantee that we will be able to do so. II. Background To help us carry out our conservation... permit to import one captive born female dhole (Cuon alpinus), from the Toronto Zoo, Toronto, Ontario, Canada, for the purpose of enhancement of the survival of the species. Applicant: Zoo New England,...

  3. NCBI nr-aa BLAST: CBRC-CFAM-28-0007 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available 8.1| transmembrane protein 20 [Canis latrans] gb|ABB48321.1| transmembrane protein 20 [Canis simensis] gb|ABB48324.1| transmembrane protein 20 [Cuon alpinus] ABB48317.1 1e-104 100% ...

  4. Great Smoky Mountains National Park Brook Trout Genetics (United States)

    National Park Service, Department of the Interior — Great Smoky Mountains National Park (GRSM) is committed to monitoring ecological and evolutionary functions and processes of park ecosystems. Brook trout (Salvelinus...

  5. Great Smoky Mountains National Park Fish Distribution (United States)

    National Park Service, Department of the Interior — Background and History The brook trout (Salvelinus fontinalis) is the only trout native to the southern Appalachian Mountains. It was once widespread in Great Smoky...

  6. Basin-Scale Variation in the Spatial Pattern of Fall Movement of Juvenile Coho Salmon in the West Fork Smith River, Oregon (United States)

    For several species of salmonids (Oncorhynchus and Salvelinus spp.) inhabiting Pacific coastal temperate streams, juvenile fish have been recorded moving between mainstem and tributary habitats during the transition from the summer dry season to the winter wet season. Movement co...

  7. Environmental contaminants in brook trout from Aroostook National Wildlife Refuge (United States)

    US Fish and Wildlife Service, Department of the Interior — In June 2012, four brook trout (Salvelinus fontinalis) were collected by angling from Chapman Pond and East Loring Lake at Aroostook NWR in northeast Maine. Two...

  8. 77 FR 5751 - Marine Recreational Fisheries of the United States; National Saltwater Angler Registry and State... (United States)


    ... pacificus Dolly varden: Salvelinus malma Sheefish or inconnu: Stenodus leucichthys Atlantic sturgeon: Acipenser oxyrhynchus oxyrhynchus Shortnose sturgeon: Acipenser brevirostrum Gulf sturgeon: Acipenser oxyrhynchus desotoi White sturgeon: Acipenser transmontanus Green sturgeon: Acipenser medirostris Angler...

  9. Migration studies and stock structure of dolly varden in the Chiniak Bay area of Kodiak Island, Alaska: Draft (United States)

    US Fish and Wildlife Service, Department of the Interior — From 1984 through 1989 a total of 31,374 Dolly Varden (Salvelinus malma) in the Chiniak Bay area of Kodiak Island, Alaska were tagged with numbered anchor tags....

  10. Beaufort Sea Coastal Fish Studies Overview and Bibliography (United States)


    113(4): 383-387. Research, Drottningholm , 35: 58-104. Damsgard, B. (1991) Smolting characters in anadro- Fabricius, 0. F. (1780) Fishes. In Fauna...conditions. INF. Soet’atten- differentiation in polymorphic arctic charr in Thingval- slab. Drottningholm . 2:17-35. lavatn Iceland. Journal of Animal...Science, no. 1287. search, Drottningholm , no. 36, p. 75-103. Bishop, F.G. (1971 ) Observations on spawning habits Fowler, H.W. (1948) Fishes of the Nueltin

  11. Cryptobiosis and its control in North American fishes. (United States)

    Woo, P T


    Cryptobiosis is caused by the haemoflagellates Cryptobia bullocki and Cryptobia salmositica. These parasites infect food fishes (e.g. flounders, salmon) on both the Atlantic and Pacific coasts of North America and clinical signs of the disease include anaemia, and abdominal distention with ascites. The virulent factor in salmonid cryptobiosis, caused by C. salmositica, is a secretory metalloprotease (200 kDa). Fish mortality may be up to 100% in the absence of treatment, consequently strategies have been developed to protect them from disease/mortality. A single dose of a live vaccine protects fish for at least 2 years, and it is via the production of complement-fixing antibodies, enhanced phagocytosis and cell-mediated cytotoxicity. Inhibition of the parasite's cysteine protease by a monoclonal antibody reduces multiplication, infectivity and survival of the parasite. Consequently, the recombinant cysteine protease (49 kDa) of the parasite will be tested as a potential vaccine. The trypanocidal drug, isometamidium chloride (1.0 mg/kg), is effective (therapeutic and prophylactic) against C. salmositica in chinook salmon. Its efficacy is significantly enhanced if it is conjugated either to a monoclonal antibody or to polyclonal antibodies from immune fish. Selective breeding of Cryptobia-resistant brook charr (innate resistance to infection) is possible, and the resistant factor(s) is controlled by a dominant Mendelian locus. In these resistant charr the parasite is lysed via the alternate pathway of complement activation (innate immunity to infection). There are also Cryptobia-tolerant charr, fish that are susceptible to infection but have no clinical disease (innate resistance to disease). In these fish, one of the natural anti-proteases, alpha2-macroglobulin, neutralises the metalloprotease secreted by C. salmositica. Production of transgenic Cryptobia-tolerant salmon is an option to vaccination and or chemotherapy. Also, transgenic pathogen-tolerant animals may

  12. ¡Bernabé, Bernabé! de Tomás de Mattos : Crisis y revisión de la identidad uruguaya


    Basile, Teresa


    El auge de la novela histórica en Uruguay parece marcar una de las líneas preponderantes en el campo literario de la postdictadura iniciada en 1985. Varias de estas novelas históricas eligen volver a los sucesos más sombríos y sangrientos de la historia del conflictivo siglo XIX: el etnocidio charrúa, las guerras civiles entre las divisas, el militarismo de Latorre, la Guerra de la Triple Alianza. ¡Bernabé, Bernabé!, (1988) de Tomás de Mattos, El príncipe de la muerte (1993) de Fernando Butaz...

  13. A Note on Derivations of Higher Order and Commutativity of Prime Rings

    Institute of Scientific and Technical Information of China (English)

    Tsai-Lien Wong


    One question posed by Chung and Luh is answered. Namely, let R be a prime ring with center Z and d a non-zero derivation of R. Suppose xdn - xam ∈ Z for all x ∈ R, where n > m are fixed non-negative integers. Then R is commutative if any one of the following conditions is satisfied: (I) m = 0;(ii) m = 1, n > 1 an even integer, and charR ≠ 2; (iii) m = 2, n > 2 an odd integer, and char R ≠ 2.

  14. Contribution on the Tabanidae (Diptera Fauna of Antalya Province

    Directory of Open Access Journals (Sweden)

    Ferhat Altunsoy


    Full Text Available In this study, carried out 35 species in Antalya province. Totally 35 species, belonging Tabanidae were determined. The species Silvius alpinus, Chrysops viduatus, Atylotus loewianus, Tabanus atropathenicus, T. bifarius, T. cordiger, T. darimonti, T. glaucopis, T. leleani, T. lunatus, T. maculicornis; T. miki, T. portschinski, T. prometheus, T. spodopteroides, T. tinctus, T. sudeticus, Hemotopota italica, H. ocelligera, H. pallens, and H. subcylindrica are the first records for this province. The total number of determined species in Antalya province reaches to 52 with the result of this study and the previous studies.

  15. Impact of UVB irradiation on vapor exchange in plants; Auswirkungen von UVB-Strahlung auf den pflanzlichen Gaswechsel

    Energy Technology Data Exchange (ETDEWEB)

    Ziegler, H.; Huebner, C.


    Different species of Rumex - ones that are adapted to high altitudes like R. alpinus, R. alpestris, R. scutatus, ones that can exist at different altitudes like R. crispus, R. acetosella, R. conglomeratus, and ones whose habitat is the lowland, like R. maritimus, R. thyrsiflorus were exposed to different doses of UVB radiation; their vapour exchange and photosynthesis and the conductivity of the stomata and pigments were measured. During the main experiments the plants were irradiated for a longer period of time with UVB-rays in two different intensities; the above-mentioned parameters were again measured. The plants of the preliminary experiments appeared outwardly without damage even after a very high dose of UVB radiation of 34.98 kJ/Sm..2Sd. Nor were the transpiration or chlorophyll content of the three species (R. maritimus, R. scutatus, R. thyrsiflorus) reduced at this radiation dose, and flavenoid contents were not lastingly changed. Only R. scutatus increased its flavenoid content at the UVB dose of 15.742 kJ/Sm..2Sd up to the highest UVB dose. During the main experiment, R. crispus and R. maritimus exhibited enhanced photosynthesis through UVB radiation; by contrast, the photosynthesis of R. alpinus was inhibited and that of R. alpestris, R. acetosella and R. conglomeratus remained largely uninfluenced. (orig./UWA) [Deutsch] Es wurden hoehenangepasste (Rumex alpinus, Rumex alpestris, Rumex scutatus), in der Hoehenverbreitung flexible (Rumex crispus, Rumex acetosella, Rumex conglomeratus) und tieflandangepasste (Rumex maritimus, Rumex thyrsiflorus) Rumex-Arten verschiedenen UVB-Dosen ausgesetzt und der Gaswechsel, die Photosynthese, die Leitwerte der Stomata und die Pigmente erfasst. In den Hauptversuchen wurde mit zwei verschiedenen UVB-Intensitaeten ueber einen laengeren Zeitraum hinweg bestrahlt und ebenfalls die oben genannten Parameter vergleichend untersucht. Es zeigte sich, dass die Pflanzen im Vorversuch selbst bei einer sehr hohen UVB-Dosis von 34

  16. 76 FR 65323 - Endangered and Threatened Species; Designation of Critical Habitat for the Southern Distinct... (United States)


    ... examples include bull trout (Salvelinus confluentus) and Puget Sound Chinook (Oncorhynchus tshawytscha... reproduction. There the USFWS used reproduction, one of several life functions, as the sole test to rule out..., `` hile it is rational to conclude areas with evidence of reproduction contain the primary...

  17. Altered steroid metabolism in several teleost species exposed to endocrine disrupting substances in refuse dump leachate

    NARCIS (Netherlands)

    Noaksson, E.; Linderoth, M.; Bosveld, A.T.C.; Balk, L.


    Endocrine disruption associated with reproductive failure has been reported previously in female perch (Perca fluviatilis) and roach (Rutilus rutilus) from Lake Molnbyggen in Sweden and in female brook trout (Salvelinus fontinalis) from Vadbäcken, a stream emptying into Molnbyggen. Both Molnbyggen a

  18. Kalispel Resident Fish Project : Annual Report, 2002.

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Todd; Olson, Jason


    In 2002 the Kalispel Natural Resource Department (KNRD) continued monitoring enhancement projects (implemented from 1996 to 1998) for bull trout (Salvelinus confluentus), westslope cutthroat (Oncorhynchus clarki lewisi) and largemouth bass (Micropterus salmoides). Additional baseline fish population and habitat assessments were conducted, in 2002, in tributaries to the Pend Oreille River. Further habitat and fish population enhancement projects were also implemented in 2002.

  19. Salmon returns and consumer fitness: growth and energy storage in stream-dwelling salmonids increases with spawning salmon abundance (United States)

    We examined how biomass of marine-derived nutrients (MDN), in the form of spawning Pacific salmon, influenced the nutritional status and nitrogen stable isotope ratios (d15N) of stream-dwelling fishes. We sampled coho salmon (Oncorhynchus kisutch) parr and juvenile Dolly Varden (Salvelinus malma) d...


    The microsomal metabolism of phenol (11 degrees C) over an annual reproductive cycle from June to December has been studied using fall spawning adult brook trout (Salvelinus fontinalis). Incubations were optimized for time, cofactor connection, pH, and microsomal protein concentr...

  1. Kalispel Resident Fish Project Annual Report, 2003.

    Energy Technology Data Exchange (ETDEWEB)

    Olson, Jason; Andersen, Todd


    In 2003 the Kalispel Natural Resource Department (KNRD) continued monitoring enhancement projects (implemented from 1996 to 1998) for bull trout (Salvelinus confluentus), westslope cutthroat (Oncorhynchus clarki lewisi) and largemouth bass (Micropterus salmoides). Additional baseline fish population and habitat assessments were conducted, in 2003, in tributaries to the Pend Oreille River. Further habitat and fish population enhancement projects were also implemented.

  2. Kalispel Resident Fish Project, 2005-2006 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Olson, Jason; Andersen, Todd (Kalispel Natural Resource Department, Usk, WA)


    In 2005 the Kalispel Natural Resource Department (KNRD) monitored its current enhancement projects for bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarki lewisi). Largemouth Bass (Micropterus salmoides) enhancement projects were also monitored. Additional baseline fish population and habitat assessments were conducted, in East River and several of its tributaries.

  3. Kalispel Resident Fish Project, 2004-2005 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Olson, Jason; Andersen, Todd


    In 2004 the Kalispel Natural Resource Department (KNRD) implemented a new enhancement monitoring project for bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarki lewisi). Largemouth bass (Micropterus salmoides) enhancement projects were also monitored. Additional baseline fish population and habitat assessments were conducted, in tributaries to the Pend Oreille River.

  4. An Engel Condition with Derivation for Multilinear Polynomials in Prime Rings

    Institute of Scientific and Technical Information of China (English)

    Vincenzo De Filippis; Onofrio Mario Di Vincenzo


    Let R be a prime algebra without non-zero nil right ideals over a commutative ring K, f(x1,..., xn) a multilinear polynomial in n variables over K, and d a non-zero derivation of R such that for any r1,..., rn ∈ R, there exists k = k(r1, ... ,rn)≥1 such that [d(f(r1,...,rn)),f(r1,... ,rn)]k = 0. If char(R)= 0, then f(x1,..., xn) is a polynomial central-valued on R. If char(R) = p > 2and f(x1,..., xn) is not a polynomial identity in p × p matrices of characteristic p, then R satisfies Sn+2(x1,... ,xn+2), and for any r1,... ,rn ∈ R, there exists t = t(r1,...,rn) ≥1 such that fpt (r1,...,rn) ∈ Z(R). Moreover, if Z(R) is finite, then f(x1,...., xn) is central-valued on R.

  5. Genome relationships among Lotus species based on random amplified polymorphic DNA (RAPD). (United States)

    Campos, L P; Raelson, J V; Grant, W F


    The ability of random amplified polymorphic DNA (RAPD) to distinguish among different taxa of Lotus was evaluated for several geographically dispersed accessions of four diploid Lotus species, L. tennis Waldst. et Kit, L. alpinus Schleich., L. japonicus (Regel) Larsen, and L. uliginosus Schkuhr and for the tetraploid L. corniculatus L., in order to ascertain whether RAPD data could offer additional evidence concerning the origin of the tetraploid L. corniculatus. Clear bands and several polymorphisms were obtained for 20 primers used for each species/accession. The evolutionary pathways among the species/accessions presented in a cladogram were expressed in terms of treelengths giving the most parsimonious reconstructions. Accessions within the same species grouped closely together. It is considered that L. uliginosus which is most distantly related to L. corniculatus, may be excluded as a direct progenitor of L. corniculatus, confirming previous results from isoenzyme studies. Lotus alpinus is grouped with accessions of L. corniculatus, which differs from previous studies. With this exception, these findings are in agreement with previous experimental studies in the L. corniculatus group. The value of the RAPD data to theories on the origin of L. corniculatus is discussed.

  6. Wild fire impact on copper, zinc, lead and cadmium distribution in soil and relation with abundance in selected plants of Lamiaceae family from Vidlic Mountain (Serbia). (United States)

    Stankov Jovanovic, V P; Ilic, M D; Markovic, M S; Mitic, V D; Nikolic Mandic, S D; Stojanovic, G S


    Fire has been considered as an improving factor in soil quality, but only if it is controlled. Severe wild fire occurred in the summer 2007 on the Vidlic Mountain (Serbia) overspreading a huge area of meadows and forests. Main soil characteristics and content of heavy metals (Cu, Pb, Cd, Zn) in different fractions obtained after sequential extraction of soil from post-fire areas and from fire non disturbed areas were studied. In four plant species of Lamiaceae family (Ajuga genevensis L., Lamium galeobdolon (L.) L., Teucrium chamaedrys L., Acinos alpinus (L.) Moench.), that grow in typical habitats of the mountain, distribution of heavy metals in aerial parts and roots was investigated too. For all samples from post-fire area cation exchange capacity and soil organic matter content are increased while rH is decreased. Fire caused slightly increased bioavailability of the observed metals but more significant rise happened in metal amounts bound to oxides and organics. The plants showed variable behavior. T. chamaedrys collected on the post-fire area contained elevated concentrations of all analyzed metals. A. alpinus showed higher phytoaccumulation for Zn and Cd, while the other two plant species for Pb and Cd in the post-fire areas.

  7. Aporte indígena a la población uruguaya: ¿Charruas o Guaranies?

    Directory of Open Access Journals (Sweden)

    Sans, Mónica


    Full Text Available Durante el siglo XIX, las reiteradas matanzas da indígenas llevaron a forjar la identidad de los uruguayos como de "país de inmigrantes", sin continuidad entre los habitantes históricos y los actuales. Sin embargo, diversos historiadores plantean un aparte de varios miles de guaraníes, mientras que Re hace referencia al reparto da algunos cientos de mujeres y niños charrúas. Ej la década de 1980, el análisis de marcadores genéticos mostró contribución indígena a la población en distintas regiones del país, y posteriormente, que este aporte era mayor al considerar linajes maternos. Para investigar el origen de estas indígenas, y la posible continuidad genética desde tiempos prehistóricos, se analiza ADNmt de habitantes prehistóricos, históricos y actuales dal territorio uruguayo. Se compara la frecuencia de los haplogrupos indígenas y secuencias de la región hiparvariable I de población actual (con 7 individuos inhumados en "cerritos", un charrúa histórico, y grupos indígenas de América del Sur. La población uruguaya presenta mayoría de haplogrupos B y C (ambos 35, al igual que los sitios prehistóricos. Estos dos haplogrupos son comunes en Patagonia, mientras qua los guaraníes carecen casi totalmente del C, lo cual podría indicar un mayor aporte pampeano-Patagónico (macro-etnia charrúa que guaraní, contrariamente a lo esperado. Además, se pudo establecer continuidad poblacional desde la prehistoria, marcada por la presencia de una mutación rara asociada ah haplogrupo C (Transición en 1688.

  8. Suppression of invasive lake trout in an isolated backcountry lake in Glacier National Park (United States)

    Fredenberg, C. R.; Muhlfeld, Clint C.; Guy, Christopher S.; D'Angelo, Vincent S.; Downs, Christopher C.; Syslo, John M.


    Fisheries managers have implemented suppression programmes to control non-native lake trout, Salvelinus namaycush (Walbaum), in several lakes throughout the western United States. This study determined the feasibility of experimentally suppressing lake trout using gillnets in an isolated backcountry lake in Glacier National Park, Montana, USA, for the conservation of threatened bull trout, Salvelinus confluentus (Suckley). The demographics of the lake trout population during suppression (2009–2013) were described, and those data were used to assess the effects of suppression scenarios on population growth rate (λ) using an age-structured population model. Model simulations indicated that the population was growing exponentially (λ = 1.23, 95% CI: 1.16–1.28) prior to suppression. However, suppression resulted in declining λ(0.61–0.79) for lake trout, which was concomitant with stable bull trout adult abundances. Continued suppression at or above observed exploitation levels is needed to ensure continued population declines.

  9. Environmental Assessment for A-29 Light Air Support (LAS) Training Beddown (United States)


    Home AFB ROI Common Name Scientific Name Federal Listing State Listing State/County Fish Bull trout1 Salvelinus confluentus T T (ID) ID-Elmore...Training Beddown 4-35 August 2014 Several federally-listed species potentially occur under the airspace. Aquatic habitat for the bull exercises, as measured, did not appear to substantially impact red-cockaded woodpecker reproductive success and productivity (Delaney et al. 2011

  10. First evidence of successful natural reproduction by planted lake trout in Lake Huron (United States)

    Nester, Robert T.; Poe, Thomas P.


    Twenty-two lake trout (Salvelinus namaycush) swim-up fry, 24-27 mm long, were captured with emergent fry traps and a tow net in northwestern Lake Huron on a small nearshore reef off Alpena, Michigan, between May 10 and June 1, 1982. These catches represent the first evidence of successful production of swim-up fry by planted, hatchery-reared lake trout in Lake Huron since the lake trout rehabilitation program began in 1973.

  11. Altered steroid metabolism in several teleost species exposed to endocrine disrupting substances in refuse dump leachate



    Endocrine disruption associated with reproductive failure has been reported previously in female perch (Perca fluviatilis) and roach (Rutilus rutilus) from Lake Molnbyggen in Sweden and in female brook trout (Salvelinus fontinalis) from Vadbäcken, a stream emptying into Molnbyggen. Both Molnbyggen and Vadbäcken have been contaminated by toxic leachate from a municipal refuse dump. In this study, female perch were caught in Molnbyggen and the reference lake, Lake Djursjön, to further investiga...

  12. Kalispel Resident Fish Project : Annual Report, 2001.

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Todd


    In 2001 the Kalispel Natural Resource Department (KNRD) continued assessing habitat and population enhancement projects for bull trout (Salvelinus confluentus), westslope cutthroat (Oncorhynchus clarki lewisi) and largemouth bass (Micropterus salmoides). Habitat enhancement measures, as outlined in recommendations from the 1996, 1997, and 1998 annual reports, were monitored during field season 1999, 2000, and 2001. Post assessments were used to evaluate habitat quality, stream morphology and fish populations where enhancement projects were implemented.

  13. Evaluation of hypotheses concerning the origin of Lotus corniculatus (Fabaceae) using isoenzyme data. (United States)

    Raelson, J V; Grant, W F


    An isoenzyme survey was conducted for several geographically dispersed accessions of four diploid Lotus species, L. alpinus Schleich., L. japonicus (Regel) Larsen, L. tenuis Waldst. et Kit and L. uliginosus Schkuhr, and for the tetraploid L. corniculatus L., in order to ascertain whether isoenzyme data could offer additional evidence concerning the origin of L. corniculatus. Seven enzyme systems were examined using horizontal starch gel electrophoresis. These were PGI, TPI, MDH, IDH, PGM, 6-PGDH, and ME. Lotus uliginosus had monomorphic unique alleles, that were not found within L. corniculatus, at 7 loci. These loci and alleles are: Tpi1-112, Pgm1,2-110, Pgm3-82, Mdh3-68, 6-Pgdh1-110, 6-Pgdh2-98,95, and Me2-100. Other diploid taxa contained alleles found in L. corniculatus for these and other loci. The implications of the isoenzyme data to theories on the origin of L. corniculatus are discussed.

  14. Susceptibility of various Japanese freshwater fish species to an isolate of viral haemorrhagic septicaemia virus (VHSV) genotype IVb

    DEFF Research Database (Denmark)

    Ito, Takafumi; Olesen, Niels Jørgen


    mortalities in bluegill Lepomis macrochirus used as positive controls, Japanese fluvial sculpin Cottus pollux, and iwana Salvelinus leucomaenis pluvius were 50, 80 and 0%, respectively. In Expt 2, cumulative mortalities of 100, 100 and 10% were observed in Japanese fluvial sculpin C. pollux, Japanese rice...... fish Oryzias latipes and yoshinobori Rhinogobius sp., respectively. No mortality was observed in honmoroko Gnathopogon caerulescens, akaza Liobagrus reini or Japanese striped loach Cobitis biwae. VHSV was detected by RT-PCR from samples of kidney, spleen, and brain from all dead fish, and virus re...


    Institute of Scientific and Technical Information of China (English)

    赵振山; 吴清江; 刘辉宇; 高贵琴


    @@ 目前,有关鱼类雄核发育的研究已见于川鲽(Platichthys flesus)、马苏大麻哈鱼(Oncorhynchus masou)、虹鳟(Oncorhynchus mykiss)、红点溪鳟(Salvelinus fontinalis)、鲤鱼(Cyprnus carpio)、尼罗罗非鱼(Oreochromis niloticus)、泥鳅(Misgurnus anguillicaudatus)、斑马鱼(Danio rerio)等(Purdom,1969;Arai et al., 1979; Scheerer et al., 1991; May et al., 1988; Bongers et al., 1994;Grunina et al., 1990; Meyers, 1995; Masaoka et al., 1995; 赵振山等,1998;Corley-Smith et al., 1996).

  16. Kalispel Resident Fish Project : Annual Report, 2008.

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Todd [Kalispel Natural Resource Department


    In 2008, the Kalispel Natural Resource Department (KNRD) continued to implement its habitat enhancement projects for bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarki lewisi). Baseline fish population and habitat assessments were conducted in Upper West Branch Priest River. Additional fish and habitat data were collected for the Granite Creek Watershed Assessment, a cooperative project between KNRD and the U.S. Forest Service Panhandle National Forest (FS) . The watershed assessment, funded primarily by the Salmon Recovery Funding Board of the State of Washington, will be completed in 2009.

  17. Hungry Horse Dam Fisheries Mitigation; Kokanee Stocking and Monitoring in Flathead Lake, 1995 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Fredenberg, Wade; Carty, Daniel (US Fish and Wildlife Service, Kalispell, MT); Cavigli, Jon (Montana Department of Fish, Wildlife and Parks, Kalispell, MT)


    The operation of Hungry Horse Dam on the South Fork-of the Flathead River reduced the reproductive success of kokanee (Oncorhynchus nerka) spawning in the Flathead River. Montana Fish, Wildlife and Parks (MFWP) and the Confederated Salish and Kootenai Tribes (CSKT) authored a mitigation plan to offset those losses. The mitigation goal, stated in the Fisheries Mitigation Plan for Losses Attributed to the Construction and Operation of Hungry Horse Dam, is to: {open_quotes}Replace lost annual production of 100,000 kokanee adults, initially through hatchery production and pen rearing in Flathead Lake, partially replacing lost forage for lake trout (Salvelinus namaycush) in Flathead Lake.{close_quotes}

  18. Etica, la academia, y las organizaciones sociales: estudio de caso

    Directory of Open Access Journals (Sweden)

    Sans, Mónica


    Full Text Available La Constitución de la República Oriental del Uruguay señala, en su Artículo 70: "El Estado propenderá al desarrollo de la investigación científica...". Sin embargo, la repatriación, a instancias de una organización de descendientes de indígenas autotitulados charrúas (ADENCH y con apoyo del Parlamento, de los restos del cacique charrúa Vaimaca Perú, muerto en cautividad en Francia en 1833, motivó controversias acerca de si los restos del mismo podían ser estudiados. Esta discusión no fue académica, si bien hubo derivaciones que influyeron sobre otras investigaciones, sino que fue suscitada por dicha organización la cual se opuso al estudio de los restos llegando a interponer varios recursos legales; uno de éstos, que condujo a un juicio, motivó un fallo histórico de un Tribunal de Apelaciones a favor del "interés general" por conocer "sin ataduras, sin secretos y sin misterios, la identidad de nuestro pueblo...". Sin embargo, y sin que se hiciera mención de dicha sentencia, el Parlamento aprobó posteriormente la Ley 17.767 que prohíbe expresamente la realización de "experimentos y estudios científicos" en los restos de Vaimaca Perú, violando según algunos autores, la propia Constitución y planteando, además de la discordancia entre dos Poderes del Estado, la oposición entre diversos intereses. A partir de estos hechos se propone analizar los valores éticos que subyacen a la investigación, si deben plantearse limitaciones a ésta y de ser así, cuáles, e incluso, cómo se debe normar sobre las mismas.

  19. Diet overlap of top-level predators in recent sympatry: bull trout and nonnative lake trout (United States)

    Guy, Christopher S.; McMahon, Thomas E.; Fredenberg, Wade A.; Smith, Clinton J.; Garfield, David W.; Cox, Benjamin S.


    The establishment of nonnative lake trout Salvelinus namaycush in lakes containing lacustrine–adfluvial bull trout Salvelinus confluentus often results in a precipitous decline in bull trout abundance. The exact mechanism for the decline is unknown, but one hypothesis is related to competitive exclusion for prey resources. We had the rare opportunity to study the diets of bull trout and nonnative lake trout in Swan Lake, Montana during a concomitant study. The presence of nonnative lake trout in Swan Lake is relatively recent and the population is experiencing rapid population growth. The objective of this study was to evaluate the diets of bull trout and lake trout during the early expansion of this nonnative predator. Diets were sampled from 142 bull trout and 327 lake trout during the autumn in 2007 and 2008. Bull trout and lake trout had similar diets, both consumed Mysis diluviana as the primary invertebrate, especially at juvenile stages, and kokanee Oncorhynchus nerka as the primary vertebrate prey, as adults. A diet shift from primarily M. diluviana to fish occurred at similar lengths for both species, 506 mm (476–545 mm, 95% CI) for bull trout and 495 mm (470–518 mm CI) for lake trout. These data indicate high diet overlap between these two morphologically similar top-level predators. Competitive exclusion may be a possible mechanism if the observed overlap remains similar at varying prey densities and availability.

  20. Kalispel Resident Fish Project : Annual Report, 1995.

    Energy Technology Data Exchange (ETDEWEB)

    Maroney, Joseph; Donley, Christopher; Scott, Jason; Lockwood, Jr., Neil


    In 1995 the Kalispel Natural Resource Department (KNRD) in conjunction with the Washington Department of Fish and Wildlife (WDFW) initiated the implementation of a habitat and population enhancement project for bull trout (Salvelinus confluentus), westslope cutthroat trout (Oncorhynchus clarki lewisi) and largemouth bass (Micropterus salmoides). Habitat and population assessments were conducted in seven tributaries of the Box Canyon reach of the Pend Oreille River. Assessments were used to determine the types and quality of habitat that were limiting to native bull trout and cutthroat trout populations. Assessments were also used to determine the effects of interspecific competition within these streams. A bull trout and brook trout (Salvelinus fontinalis) hybridization assessment was conducted to determine the degree of hybridization between these two species. Analysis of the habitat data indicated high rates of sediment and lack of wintering habitat. The factors that contribute to these conditions have the greatest impact on habitat quality for the tributaries of concern. Population data suggested that brook trout have less stringent habitat requirements; therefore, they have the potential to outcompete the native salmonids in areas of lower quality habitat. No hybrids were found among the samples, which is most likely attributable to the limited number of bull trout. Data collected from these assessments were compiled to develop recommendations for enhancement measures. Recommendations for restoration include riparian planting and fencing, instream structures, as well as, removal of non-native brook trout to reduce interspecific competition with native salmonids in an isolated reach of Cee Cee Ah Creek.

  1. Heat transfer in fish: are short excursions between habitats a thermoregulatory behaviour to exploit resources in an unfavourable thermal environment? (United States)

    Pépino, Marc; Goyer, Katerine; Magnan, Pierre


    Temperature is the primary environmental factor affecting physiological processes in ectotherms. Heat-transfer models describe how the fish's internal temperature responds to a fluctuating thermal environment. Specifically, the rate coefficient (k), defined as the instantaneous rate of change in body temperature in relation to the difference between ambient and body temperature, summarizes the combined effects of direct thermal conduction through body mass, passive convection (intracellular and intercellular fluids) and forced convective heat transfer (cardiovascular system). The k-coefficient is widely used in fish ecology to understand how body temperature responds to changes in water temperature. The main objective of this study was to estimate the k-coefficient of brook charr equipped with internal temperature-sensitive transmitters in controlled laboratory experiments. Fish were first transferred from acclimation tanks (10°C) to tanks at 14, 19 or 23°C (warming experiments) and were then returned to the acclimation tanks (10°C; cooling experiments), thus producing six step changes in ambient temperature. We used non-linear mixed models to estimate the k-coefficient. Model comparisons indicated that the model incorporating the k-coefficient as a function of absolute temperature difference (dT: 4, 9 and 13°C) best described body temperature change. By simulating body temperature in a heterogeneous thermal environment, we provide theoretical predictions of maximum excursion duration between feeding and resting areas. Our simulations suggest that short (i.e. thermal environment.

  2. Měkkýši Českého lesa – IV. Nové údaje pro jižní část Českého lesa

    Directory of Open Access Journals (Sweden)

    Jitka Horáčková


    Full Text Available Data on recent molluscan fauna in the southern part of the Český Les Mts., with additional data from the phytogeographic district of the Plzeňská Pahorkatina hills, are presented. Altogether, 63 species (62 species of Gastropoda and 1 species of Bivalvia were recorded at 22 selected sites. The author‘s collecting activity was focused on ruderal sites and abandoned villages along the state border. There is spruce plantation dominating in the woodlands with scarce malacofauna. The common forest species dominate there, with the presence of montane and submontane elements, such as Clausilia cruciata, Vertigo substriata, and Discus ruderatus, which occur in the rest of preserved deciduous forests. The record of Atlantic Oxychilus alliarius species is the fifth known in Czech Republic. The montane snail of Clausilia cruciata was found at one site at very low altitude of 550 m a.s.l. A slug species Arion alpinus, never found in this area before, was recorded at five sites. Its occurrence here is the westernmost one in the Czech Republic. The elements of open habitats presented by xerotherm sites and open wetlands were not recorded, except for the species Vallonia costata and Vallonia excentrica occurring only at the ruins of abandoned villages and their surroundings.

  3. The chemical and biological response of two remote mountain lakes in the Southern Central Alps (Italy to twenty years of changing physical and chemical climate

    Directory of Open Access Journals (Sweden)

    Andrea LAMI


    Full Text Available Two small high mountain lakes in the Alps were monitored in 1984-2003 to follow their response to changes in human impact, such as deposition of atmospheric pollutants, fish stocking and climate change. The results were compared to occasional samplings performed in the 1940s, and to the remains found in sediment cores. When monitoring started, the most acid-sensitive of them, Lake Paione Superiore, was acidified, with evident effects in its flora and fauna: benthic diatoms assemblage was shifted towards acidophilous species, and zooplankton lost the dominant species, Arctodiaptomus alpinus. Palaeolimnological studies outlined that lake acidification paralleled the increasing input of long-range transported industrial pollutants, traced by spherical carbonaceous particles. On the contrary, the biota of Lake Paione Inferiore appeared to be mainly affected by fish stocking. In the last twenty years, decrease in acid load from the atmosphere led to an improvement in lake water quality, with an increase in both pH and alkalinity. First signs of biological recovery were identified, such as change in diatom flora and appearance of sensitive species among benthic insects. However, climate change and episodic deposition of Saharan dust were important driving factors controlling lake water chemistry. Further monitoring to assess the effects of climate change and of the increasing load of nitrogen and other pollutants is recommended.

  4. Optimization of extraction conditions for secondary biomolecules from various plant species

    Directory of Open Access Journals (Sweden)

    Šibul Filip S.


    Full Text Available Extraction of plant secondary metabolites is an essential step in isolation of natural products. Non-optimized extraction conditions can lead to losses, degradation and modification of the biomolecules. In this paper, the influence of different solvent mixtures, solvent amounts, temperature, extraction time, and procedures for defatting on yield and profile of various classes of secondary metabolites was investigated. Rumex alpinus was used for the extraction of anthraquinones, Glycine max for isoflavonoids, Chaerophyllum bulbosum for flavonoids and phenolic acids, Anthriscus sylvestris for lignans and coumarins, alkaloids were extracted from Lupinus albus and sesquiterpene lactones from Artemisia absinthium. Extraction efficiency was evaluated by use of LC-DAD-ESI-MS/MS. The compromise extraction solvent for all of the examined compounds is 80 % methanol, mixed in ratio 13 : 1 with plant material. Maceration should last for six hours, repeated four times with fresh solvent. Defatting of the extracts does not lead to significant losses of the compounds of interest. It is acceptable to use extraction and evaporation temperature of 60ºC, while the extracts should be stored in the dark, on -20ºC. [Projekat Ministarstva nauke Republike Srbije, br. 172058

  5. A Pathological Late Pleistocene canid from San Sidero (Italy): implications for social- and feeding-behaviour (United States)

    Iurino, Dawid Adam; Fico, Rosario; Petrucci, Mauro; Sardella, Raffaele


    Evidence of diseases on vertebrate fossil bones can provide detailed information on many aspects of extinct animals. This study focused on pathological craniodental remains (left maxilla and dentary) referred to the canid Cuon alpinus unearthed from a Late Pleistocene karst filling deposit at San Sidero (Apulia, southern Italy). These fossils show clear evidence of a chronic periodontitis that caused the animal's death. Clinical diagnosis of the disease and the timing of its development have been defined on the basis of a veterinary odontostomatology approach, in addition to radiographic and tomographic techniques. From the initiation of the infection until death, a time span of at least 6 months occurred, and three main steps have been defined: (1) the bacterial infections of the buccal cavity turning into severe periodontitis, (2) the fracture of the lower carnassial and (3) the loss of teeth due to the worsening infection that deformed and/or eroded maxillary and mandibular bones and enlarged alveoli. The analysis of the palaeopathology also provides information about the biomechanics of the bite, on the feeding behaviour and on the relationships of injured members in a pack of Late Pleistocene canids.

  6. Radio-transmitted electromyogram signals as indicators of swimming speed in lake trout and brown trout

    DEFF Research Database (Denmark)

    Thorstad, E.B.; Økland, F.; Koed, Anders


    Swimming speed and average electromyogram (EMG) pulse intervals were highly correlated in individual lake trout Salvelinus namaycush (r(2)=0.52-0.89) and brown trout Salmo trutta (r(2)=0.45-0.96). High correlations were found also for pooled data in both lake trout (r(2)=0.90) and brown trout...... of the Ema stock (r(2)=0.96) and Laerdal stock (r(2)=0.96). The linear relationship between swimming speed and average EMG pulse intervals differed significantly among lake trout and the brown trout stocks. This successful calibration of EMGs to swimming speed opens the possibility of recording swimming...... speed of free swimming lake trout and brown trout in situ. EMGs can also be calibrated to oxygen consumption to record energy expenditure. (C) 2000 The Fisheries Society of the British Isles...

  7. Fisheries Habitat Evaluation on Tributaries of the Coeur d`Alene Indian Reservation : 1990 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Graves, Suzy


    Ranking criteria were developed to rate 19 tributaries on the Coeur d`Alene Indiana Reservation for potential of habitat enhancement for westslope cutthroat trout, Oncorhynchus clarki lewisi, and bull trout, Salvelinus malma. Cutthroat and bull trout habitat requirements, derived from an extensive literature review of each species, were compared to the physical and biological parameters of each stream observed during an aerial -- helicopter survey. Ten tributaries were selected for further study, using the ranking criteria that were derived. The most favorable ratings were awarded to streams that were located completely on the reservation, displayed highest potential for improvement and enhancement, had no barriers to fish migration, good road access, and a gradient acceptable to cutthroat and bull trout habitation. The ten streams selected for study were Bellgrove, Fighting, Lake, Squaw, Plummer, Little Plummer, Benewah, Alder, Hell`s Gulch and Evans creeks.

  8. Cross-basin comparison of mercury bioaccumulation in Lake Huron lake trout emphasizes ecological characteristics. (United States)

    Abma, Rachel A; Paterson, Gordon; McLeod, Anne; Haffner, G Doug


    Understanding factors influencing mercury (Hg) bioaccumulation in fish is important for examining both ecosystem and human health. However, little is known about how differing ecosystem and biological characteristics can drive Hg bioaccumulation in top predators. The present study compared and contrasted Hg bioaccumulation in multiple age classes of lake trout (Salvelinus namaycush) collected from each of Lake Huron's Georgian Bay, North Channel, and Main Basin regions. Mercury concentrations exhibited a basin specific pattern with Main Basin fish having the highest average concentration (0.19 ± 0.01 mg/kg), followed by Georgian Bay (0.15 ± 0.02 mg/kg), and North Channel (0.07 ± bioaccumulation. No significant difference was determined between the relationships describing Hg concentration and age between Main Basin and Georgian Bay fish (p bioaccumulation in feral fish communities.

  9. Status of Oregon's Bull Trout.

    Energy Technology Data Exchange (ETDEWEB)

    Buchanan, David V.; Hanson, Mary L.; Hooton, Robert M.


    Limited historical references indicate that bull trout Salvelinus confluentus in Oregon were once widely spread throughout at least 12 basins in the Klamath River and Columbia River systems. No bull trout have been observed in Oregon's coastal systems. A total of 69 bull trout populations in 12 basins are currently identified in Oregon. A comparison of the 1991 bull trout status (Ratliff and Howell 1992) to the revised 1996 status found that 7 populations were newly discovered and 1 population showed a positive or upgraded status while 22 populations showed a negative or downgraded status. The general downgrading of 32% of Oregon's bull trout populations appears largely due to increased survey efforts and increased survey accuracy rather than reduced numbers or distribution. However, three populations in the upper Klamath Basin, two in the Walla Walla Basin, and one in the Willamette Basin showed decreases in estimated population abundance or distribution.

  10. [Karyotype and divergence of stream Dolly Varden from the Southern Sakhalin]. (United States)

    Frolov, S V; Miller, I N; Frolova, V N


    The karyotype of stream Dolly Varden inhabiting a tributary of the Belaya River (the basin of Naiba River, southern Sakhalin) was determined (2n = 82 and NF = 98 + 2). According to the main characteristics (chromosome number and arm number, the presence of a pair of marker submeta-subtelocentric chromosomes with nucleolus organizer regions (NORs), one pair of large acrocentric chromosomes, and one pair of subtelocentric chromosomes), this karyotype is identical to the karyotype of anadromous southern Dolly Varden from Salvelinus malma krasheninnikovi of Primorye and Japan. However, in most stream Dolly Varden individuals, additional active nucleolus organizer regions (NORs) located in telomeric and paracentric regions of two to three pairs of acrocentric chromosomes were revealed. It is suggested that the stream and anadromous southern forms of Dolly Varden are evolutionarily related NORs that are silent in the anadromous souther form are active in the stream form. Possible causes of these differences in NOR activity are discussed.

  11. Comparative study of genome divergence in salmonids with various rates of genetic isolation. (United States)

    Shubina, Elena A; Nikitin, Mikhail A; Ponomareva, Ekaterina V; Goryunov, Denis V; Gritsenko, Oleg F


    The aim of the study is a comparative investigation of changes that certain genome parts undergo during speciation. The research was focused on divergence of coding and noncoding sequences in different groups of salmonid fishes of the Salmonidae (Salmo, Parasalmo, Oncorhynchus, and Salvelinus genera) and the Coregonidae families under different levels of reproductive isolation. Two basic approaches were used: (1) PCR-RAPD with a 20-22 nt primer design with subsequent cloning and sequencing of the products and (2) a modified endonuclease restriction analysis. The restriction fragments were shown with sequencing to represent satellite DNA. Effects of speciation are found in repetitive sequences. The revelation of expressed sequences in the majority of the employed anonymous loci allows for assuming the adaptive selection during allopatric speciation in isolated char forms.

  12. Comparative Study of Genome Divergence in Salmonids with Various Rates of Genetic Isolation

    Directory of Open Access Journals (Sweden)

    Elena A. Shubina


    Full Text Available The aim of the study is a comparative investigation of changes that certain genome parts undergo during speciation. The research was focused on divergence of coding and noncoding sequences in different groups of salmonid fishes of the Salmonidae (Salmo, Parasalmo, Oncorhynchus, and Salvelinus genera and the Coregonidae families under different levels of reproductive isolation. Two basic approaches were used: (1 PCR-RAPD with a 20–22 nt primer design with subsequent cloning and sequencing of the products and (2 a modified endonuclease restriction analysis. The restriction fragments were shown with sequencing to represent satellite DNA. Effects of speciation are found in repetitive sequences. The revelation of expressed sequences in the majority of the employed anonymous loci allows for assuming the adaptive selection during allopatric speciation in isolated char forms.

  13. Toxicity of fluoride to aquatic species and evaluation of toxicity modifying factors. (United States)

    Pearcy, Krysta; Elphick, James; Burnett-Seidel, Charlene


    The present study was performed to investigate the toxicity of fluoride to a variety of freshwater aquatic organisms and to establish whether water quality variables contribute substantively to modifying its toxicity. Water hardness, chloride, and alkalinity were tested as possible toxicity modifying factors for fluoride using acute toxicity tests with Hyalella azteca and Oncorhynchus mykiss. Chloride appeared to be the major toxicity modifying factor for fluoride in these acute toxicity tests. The chronic toxicity of fluoride was evaluated with a variety of species, including 3 fish (Pimephales promelas, O. mykiss, and Salvelinus namaycush), 3 invertebrates (Ceriodaphnia dubia, H. azteca, and Chironomus dilutus), 1 plant (Lemna minor), and 1 alga (Pseudokirchneriella subcapitata). Hyalella azteca was the most sensitive species overall, and O. mykiss was the most sensitive species of fish. The role of chloride as a toxicity modifying factor was inconsistent between species in the chronic toxicity tests.

  14. Addressing catch mechanisms in gillnets improves modeling of selectivity and estimates of mortality rates: a case study using survey data on an endangered stock of Arctic char

    DEFF Research Database (Denmark)

    Jonsson, T.; Setzer, M.; Pope, John George;


    Estimation of fish stock size distributions from survey data requires knowledge about gear selectivity. However, selectivity models rest on assumptions that seldom are analyzed. Departures from these can lead to misinterpretations and biased management recommendations. Here, we use survey data...... on great Arctic char (Salvelinus umbla) to analyze how correcting for entanglement of fish and nonisometric growth might improve estimates of selectivity curves, and subsequently estimates of size distribution and age-specific mortality. Initial selectivity curves, using the entire data set, were wide...... and asymmetric, with poor model fits. Removing potentially nonmeshed fish had the greatest positive effect on model fit, resulting in much narrower and less asymmetric selection curves, while attempting to take nonisometric growth into account, by using girth rather than length, improved model fit...

  15. Lake trout in the Great Lakes: Basin-wide stock collapse and binational restoration (United States)

    Hansen, Michael J.; Taylor, William W.; Ferreri, C. Paola


    The lake trout (Salvelinus namaycush) was important to the human settlement of each of the Great Lakes, and underwent catastrophic collapses in each lake in the nineteenth and twentieth centuries. The timing of lake trout stock collapses were different in each lake, as were the causes of the collapses, and have been the subject of much scientific inquiry and debate. The purpose of this chapter is to summarize and review pertinent information relating historical changes in Great Lakes lake trout stocks, binational efforts to restore those stocks, and progress toward stock restoration. This presentation attempts to generalize patterns across the Great Lakes, rather than to focus within each lake. Lake specific analyses have been used to understand lake specific causes and effects, but there is continuing debate about some of these causes and effects. A basinwide review may suggest mechanisms for observed changes that are not evident by lake specific analysis.

  16. Exposure-related effects of Pseudomonas fluorescens, strain CL145A, on coldwater, coolwater, and warmwater fish (United States)

    Luoma, James A.; Weber, Kerry L.; Denise A. Mayer,


    The exposure-related effects of a commercially prepared spray-dried powder (SDP) formulation of Pseudomonas fluorescens, strain CL145A, were evaluated on coldwater, coolwater, and warmwater fish endemic to the Great Lakes and Upper Mississippi River Basins. Nine species of young-of-the-year fish were exposed to SDP for 24 hours by using continuous-flow, serial-dilution exposure systems at temperatures of 12 degrees Celsius (°C; 2 species; Oncorhynchus mykiss [rainbow trout] and Salvelinus fontinalis [brook trout]), 17 °C (3 species; Perca flavescens [yellow perch], Sander vitreus [walleye], and Acipenser fulvescens [lake sturgeon]), or 22 °C (4 species; Micropterus salmoides [largemouth bass], Micropterus dolomieu [smallmouth bass], Lepomis macrochirus [bluegill sunfish], and Ictalurus punctatus [channel catfish]).

  17. CAIRNES Y VICHADEROS EN LAS TIERRAS ALTAS DE URUGUAY / Cairnes and vichaderos in the highlands of Uruguay

    Directory of Open Access Journals (Sweden)

    Moira Sotelo


    Full Text Available El trabajo se centra en el estudio de una manifestación arqueológica compuesta por estructuras de piedras, denominadas en Uruguay como cairnes y vichaderos. Estas estructuras fueron construidas con piedras mediante la agregación e imbricación de bloques, dando lugar a la formación de montículos y círculos, ubicados en cerros y sierras del centro-norte y este del país. En general se ha aceptado que fueron hechas por las poblaciones indígenas (Guenoa-minuanes y quizás Charrúas que habitaban la región en tiempos de la llegada de los europeos, y que su uso estaría relacionado a entierros humanos, a eventos rituales y al control territorial. Estudios actuales se encaminan a profundizar en la cronología y funcionalidad de cairnes y vichaderos, así como sobre los grupos humanos que los construyeron. En esta oportunidad se presentan los resultados obtenidos con la revisión de fuentes documentales históricas, con referencias a prácticas funerarias y entierros con piedras. Por otro lado, se reseñan los resultados obtenidos con una prospección diseñada a partir de esa información, en el norte del territorio uruguayo. Los trabajos señalan un correlato espacial entre las fuentes documentales y el registro arqueológico, a la vez que confirman la magnitud de este fenómeno. Palabras clave: Tierras altas, estructuras de piedras, entierros humanos, documentos históricos.    Abstract This paper focuses on the study of an archaeological manifestation, composed by stone structures, known in Uruguay as cairnes and vichaderos. These structures were built by aggregating stone blocks, forming mounds and circles, hills and mountains located in north-central and east of Uruguay. It is generally accepted these stone structures were used as part of burial practices among indigenous groups (Guenoa-minuanes and perhaps Charrúas who inhabited the region before and after the European arrival. The social practices of indigenous peoples led to the

  18. Adaptive Management of Bull Trout Populations in the Lemhi Basin (United States)

    Peterson, James T.; Tyre, Andrew J.; Converse, Sarah J.; Bogich, Tiffany L.; Miller, Damien; Post van der Burg, Max; Thomas, Carmen; Thompson, Ralph J.; Wood, Jeri; Brewer, Donna; Runge, Michael C.


    The bull trout Salvelinus confluentus, a stream-living salmonid distributed in drainages of the northwestern United States, is listed as threatened under the Endangered Species Act because of rangewide declines. One proposed recovery action is the reconnection of tributaries in the Lemhi Basin. Past water use policies in this core area disconnected headwater spawning sites from downstream habitat and have led to the loss of migratory life history forms. We developed an adaptive management framework to analyze which types of streams should be prioritized for reconnection under a proposed Habitat Conservation Plan. We developed a Stochastic Dynamic Program that identified optimal policies over time under four different assumptions about the nature of the migratory behavior and the effects of brook trout Salvelinus fontinalis on subpopulations of bull trout. In general, given the current state of the system and the uncertainties about the dynamics, the optimal policy would be to connect streams that are currently occupied by bull trout. We also estimated the value of information as the difference between absolute certainty about which of our four assumptions were correct, and a model averaged optimization assuming no knowledge. Overall there is little to be gained by learning about the dynamics of the system in its current state, although in other parts of the state space reducing uncertainties about the system would be very valuable. We also conducted a sensitivity analysis; the optimal decision at the current state does not change even when parameter values are changed up to 75% of the baseline values. Overall, the exercise demonstrates that it is possible to apply adaptive management principles to threatened and endangered species, but logistical and data availability constraints make detailed analyses difficult.

  19. Thermal regimes, nonnative trout, and their influences on native Bull Trout in the Upper Klamath River Basin, Oregon (United States)

    Benjamin, Joseph R.; Heltzel, Jeannie; Dunham, Jason; Heck, Michael; Banish, Nolan P.


    The occurrence of fish species may be strongly influenced by a stream’s thermal regime (magnitude, frequency, variation, and timing). For instance, magnitude and frequency provide information about sublethal temperatures, variability in temperature can affect behavioral thermoregulation and bioenergetics, and timing of thermal events may cue life history events, such as spawning and migration. We explored the relationship between thermal regimes and the occurrences of native Bull Trout Salvelinus confluentus and nonnative Brook Trout Salvelinus fontinalis and Brown Trout Salmo trutta across 87 sites in the upper Klamath River basin, Oregon. Our objectives were to associate descriptors of the thermal regime with trout occurrence, predict the probability of Bull Trout occurrence, and estimate upper thermal tolerances of the trout species. We found that each species was associated with a different suite of thermal regime descriptors. Bull Trout were present at sites that were cooler, had fewer high-temperature events, had less variability, and took longer to warm. Brook Trout were also observed at cooler sites with fewer high-temperature events, but the sites were more variable and Brook Trout occurrence was not associated with a timing descriptor. In contrast, Brown Trout were present at sites that were warmer and reached higher temperatures faster, but they were not associated with frequency or variability descriptors. Among the descriptors considered, magnitude (specifically June degree-days) was the most important in predicting the probability of Bull Trout occurrence, and model predictions were strengthened by including Brook Trout occurrence. Last, all three trout species exhibited contrasting patterns of tolerating longer exposures to lower temperatures. Tolerance limits for Bull Trout were lower than those for Brook Trout and Brown Trout, with contrasts especially evident for thermal maxima. Our results confirm the value of exploring a suite of thermal

  20. Bull Trout Distribution and Abundance in the Waters on and Bordering the Warm Springs Indian Reservation, 2000 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Brun, Christopher


    The range of bull trout (Salvelinus confluentus) in the Deschutes River basin has decreased from historic levels due to many factors including dam construction, habitat degradation, brook trout introduction and eradication efforts. While the bull trout population appears to be stable in the Metolius River-Lake Billy Chinook system they have been largely extirpated from the upper Deschutes River (Buchanan et al. 1997). Little was known about bull trout in the lower Deschutes basin until BPA funded project No.9405400 began during 1998. In this progress report we describe the findings from the third year (2000) of the multi-year study aimed at determining the life history, genetics, habitat needs and limiting factors of bull trout in the lower Deschutes subbasin. Juvenile bull trout and brook trout (Salvelinus fontinalis) relative abundance was assessed in the Warm Springs River and Shitike Creek by night snorkeling. In the Warm Springs R. juvenile bull trout were slightly more numerous than brook trout, however, both were found in low densities. Relative densities of both species declined from 1999 observations. Juvenile bull trout vastly out numbered brook trout in Shitike Cr. Relative densities of juvenile bull trout increased while brook trout abundance was similar to 1999 observations in eight index reaches. The utility of using index reaches to monitor trends in juvenile bull trout and brook trout relative abundance was assessed in the Warm Springs R. for the second year. Mean relative densities of both species, within the index reaches was slightly higher than what was observed in a 2.4 km control reach. Mill Creek was surveyed for the presence of juvenile bull trout. The American Fisheries Society ''Interim protocol for determining bull trout presence'' methodology was field tested. No bull trout were found in the 2 km survey area.

  1. Use of Barley for the Purification of Aquaculture Wastewater in a Hydroponics System

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    A. M. Snow


    Full Text Available Barley was examined for its ability to remove nutrients from aquaculture wastewater. The effects of seed sterilization using ethanol and bleach and seed density on germination and plant growth were investigated. Surface sterilization of barley seeds had a negative impact on germination. Increasing the ethanol concentration and/or the bleach concentration reduced the germination percentage. Barley seeds were first germinated in water in the hydroponics system. The seedlings then received wastewater from an aquaculture system stocked with Arctic charr. During the experiment, the crops grew rapidly and fairly uniformly and showed no signs of mineral deficiency or disease. The average crop height at harvest was 25.5 cm and the yield varied from 25 to 59 t haˉ1, depending on the seed density. The hydroponically grown barley was able to significantly reduce the pollution load of the aquaculture wastewater. The TS, COD, NH4+-N, NO2--N, NO3--N, and PO43--P reductions ranged from 52.7 to 60.5%, from 72.9 to 83.1%, from 76.0 to 76.0%, from 97.6 to 99.2%, from 76.9 to 81.6% and from 87.1 to 95.1%, respectively. However, the effluent produced from the hydroponics system had slightly higher levels of TS (420-485 mg Lˉ1 than the 480 mg Lˉ1 recommended for aquatic animals. A sedimentation/filtration unit should be added to the hydroponics system.

  2. Acumulación, removilización, absorción postantesis y eficiencia de utilización de nitrógeno en trigo bajo diferentes labranzas y fertilizaciones

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    Golik Silvina Inés


    Full Text Available El objetivo de este trabajo fue analizar la acumulación, removilización, absorción postantesis y la eficiencia en la utilización de N bajo dos sistemas de labranza (reja y cincel y diferentes tipos de fertilización, en los cultivares de trigo pan Buck Pronto y Buck Charrúa. Los tratamientos de fertilización fueron: testigo sin el agregado de N, aplicación de 90 kg ha-1 de N como urea a la siembra, aplicación de 90 kg ha-1 de N como nitrato de amonio calcáreo a la siembra y aplicación de N como urea y como nitrato de amonio calcáreo en dosis de 45 kg ha-1 a la siembra más 45 kg ha-1 a fin de macollaje, respectivamente. Se encontraron diferencias en el N acumulado entre sistemas de labranzas; con cincel se acumuló 18 kg ha-¹ más que bajo reja, pero esto no se tradujo en el porcentaje de N contribuido al grano por removilización ni por absorción postantesis. La fertilización aumentó el N acumulado en un promedio de 50 kg ha-1. A su vez provocó un aumento en la contribución al grano del N removilizado, pero no mejoró el aporte del N absorbido postantesis, ni aún en la aplicación en dos momentos. Los cultivares presentaron diferencias en el N acumulado y en el porcentaje aportado al grano por removilización y absorción postantesis. La eficiencia de utilización del N dependió de la labranza y de la fertilización.

  3. La verificación de los datos en biodemografía: El ejemplo de Villa Soriano, Uruguay

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    Barreto, Isabel


    Full Text Available La población de Villa Soriano (Departamento de Soriano, Uruguay, fue fundada como una reducción indígena en el siglo XVII. En la misma se analizaron desde el año 2000 distintos aspectos de la población, determinándose, a pesar del descenso demográfico que ha tenido la población, la presencia de descendientes indígenas. El presente trabajo tiene como objetivo discutir a partir de un caso concreto, la verificación de la información en Biodemografía. Los estudios realizados en Villa Soriano permitieron la reconstrucción genealógica de 265 familias, ubicándose a partir de la información familiar y la de archivos hasta 13 generaciones a partir del presente. La reconstrucción de genealogías, utilizando GenePro, permitió detectar nueve linajes indígenas, muchos de los cuales provienen de los fundadores de la antigua reducción; es escasa la presencia de linajes de origen africano. Los análisis de ADNmt realizados en los 2 casos que tenían ancestría materna indígena, corroboraron la reconstrucción genealógica realizada: charrúa en un caso, guaraní en otra. A partir de los resultados, se discute la metodología empleada y su aplicación en estudios poblacionales.

  4. Prevalence of pathological conditions causing skin damage and consequently reducing its market value in domestic ruminants of Punjab, Pakistan

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    Zafar I. Chaudhry


    Full Text Available Data regarding the prevalence of skin diseases reducing the market value of skins and hides and ultimately refined leather were not available in Pakistan. The current study was conducted in the hide/skin markets and abattoirs of Lahore and Faisalabad and tanneries of Sheikhupura, Kasur and Sialkot. The record of various skin diseases and conditions damaging the skin/hide of cattle, goat and sheep was made. Lesions, extent and type of damage were recorded. A total of 21,671 skins / hides were examined out of which 3918 of skins and 600 hides were examined at the abattoirs of Lahore and Faisalabad, 6784 Skins and 1399 hides at hide markets and 8091 skins and 879 hides at tanneries. Out of total 21,671 skins / hides, 66.12% were normal and 33.88% were having some sort of damage. The data were gathered on questionnaire sheets. The prevalence of skin diseases was assessed through Strata V.9 software program. The correlation of the disease and area was analyzed by the chi-square. The prevalence of various diseases and damages due to mal-management in sheep, goats and cattle has been discussed in detail. The damages in goat skins were significantly less as compared with cattle and sheep. However, the type of defects and severity varied amongst various ruminants studied. The most common damages observed, overall in all species studied were atrophy of skin (Thin skin 6.38%, followed in descending order observed was lesions of wounds 4.94%, old lesions of pox 4.82%, flaying cuts 3.17%, tick infestation 3.08%, lesions caused by mites infestation 2.45%, scratches 2.33%, lesions caused by warble fly larvae 1.47%, decomposition 1.32%, charr (fibrosis 1.28%, ringworm infection 1.10%, extensive soiling by dung 0.84%, chronic abscesses 0.46%, and Lice infestation 0.17%.

  5. Research Advances in Genetics and Breeding in Salmonids%主要养殖鲑科鱼类遗传育种的研究进展

    Institute of Scientific and Technical Information of China (English)

    户国; 谷伟; 白庆利; 王炳谦


    冷水性鲑科鱼类肉质鲜美,高蛋白、高不饱和脂肪酸、营养丰富、无肌间刺、易加工,是世界性养殖鱼类,其中大西洋鲑、虹鳟和红点鲑属鱼类等主要养殖鲑科鱼类,一直是水产遗传育种领域的重要研究对象。本文简要叙述了鲑科鱼类遗传育种研究的历史和现状,主要介绍了经济性状遗传参数估计、选择育种、分子遗传与标记辅助育种等方面的研究进展,提出了我国鲑科鱼类遗传育种工作重点研究的方向。%Cold water Salmonids as a global culture fish are characterized by high quality flesh,high protein and unsaturated fat acids contents,no intermuscular bones,and easy to be processed,and particularly,Atlantic salmon(Salmo salar),rainbow trout(Oncorhynchus mykiss) and charrs are the important object of aquatic breeding and genetics research.The past and current research status of the genetics and breeding of salmonid species are briefly described,and the advances in genetic parameters estimation of economic traits,selective breeding,molecular genetics and marker assisted breeding in salmonid species are introduced in this paper.Some suggestions are made for future directions and priorities of genetics and breeding of salmonid species to provide new ideas for the study and researchers in the field of aquatic breeding and genetics.

  6. Behavioral responses to mammalian blood odor and a blood odor component in four species of large carnivores.

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    Sara Nilsson

    Full Text Available Only little is known about whether single volatile compounds are as efficient in eliciting behavioral responses in animals as the whole complex mixture of a behaviorally relevant odor. Recent studies analysing the composition of volatiles in mammalian blood, an important prey-associated odor stimulus for predators, found the odorant trans-4,5-epoxy-(E-2-decenal to evoke a typical "metallic, blood-like" odor quality in humans. We therefore assessed the behavior of captive Asian wild dogs (Cuon alpinus, African wild dogs (Lycaon pictus, South American bush dogs (Speothos venaticus, and Siberian tigers (Panthera tigris altaica when presented with wooden logs that were impregnated either with mammalian blood or with the blood odor component trans-4,5-epoxy-(E-2-decenal, and compared it to their behavior towards a fruity odor (iso-pentyl acetate and a near-odorless solvent (diethyl phthalate as control. We found that all four species displayed significantly more interactions with the odorized wooden logs such as sniffing, licking, biting, pawing, and toying, when they were impregnated with the two prey-associated odors compared to the two non-prey-associated odors. Most importantly, no significant differences were found in the number of interactions with the wooden logs impregnated with mammalian blood and the blood odor component in any of the four species. Only one of the four species, the South American bush dogs, displayed a significant decrease in the number of interactions with the odorized logs across the five sessions performed per odor stimulus. Taken together, the results demonstrate that a single blood odor component can be as efficient in eliciting behavioral responses in large carnivores as the odor of real blood, suggesting that trans-4,5-epoxy-(E-2-decenal may be perceived by predators as a "character impact compound" of mammalian blood odor. Further, the results suggest that odorized wooden logs are a suitable manner of environmental

  7. Organization of vegetation cover of aquatic ecosystems at Borodinskiy opencast coal mine dumps (Kansk forest-steppe, Eastern Siberia

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    D. Yu. Efimov


    Full Text Available The paper present the results of study of the floristic composition and importance of species of aquatic ecosystems on different types of technogenic surfaces of the Borodino coal mine and assessment of the impact of local factors on the structure and the dynamics of vegetation. The list of plant taxa containing 91 species of higher plants and 3 cha-rophytes. The largest amount of macrophytes species are Elodea canadensis Michx., Eleocharis palustris (L. Roem. & Schult., Hydrocharis morsus-ranae L., Potamogeton alpinus Balb., P. perfoliatus L., Sparganium emersum Rehm., Spirodela polyrhiza (L. Schleid., Typha latifolia L., Warnstorfia fluitans (Hedw. Loeske, Chara contraria A. Braun ex Kutz., the basis (up to 67.6‒70.9 % of vegetation mosaic of aquatic systems and differentiate its structure post-technogenic landscape. Sorensen index (QS = 0.63‒0.71 and Spearman rank correlation coefficient (rs = 0.29‒0.62, p < 0.01 values showed the greatest similarity between the species composition of the aquatic complexes arising on mineral surfaces planned dumps. The low level of similarity (QS = 0.13‒0.45; rs = 0.25‒0.34, p < 0.05 in spe-cies composition is typical fir ponds and wetlands formed around the perimeter of the heaps along the erosion of slopes. Non-parametric analysis of variance showed a statistically significant (p < 0.001 differentiation of the species composition of the variables values of the analyzed environmental factors: the direction of reclamation, type and age of geomorphic surfaces dumps. Aquatic complexes significantly complement and enrich the mosaic of man-made landscape of the Borodino coal mine, the potential of their diversity should be taken into account when developing plans and strategies for reclamation of disturbed areas.

  8. Sarcocystosis of chital-dhole: conditions for evolutionary stability of a predator parasite mutualism

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    Watve Milind G


    Full Text Available Abstract Background For parasites with a predator-prey life cycle, the completion of the life cycle often depends on consumption of parasitized prey by the predator. In the case of such parasite species the predator and the parasite have common interests and therefore a mutualistic relationship is possible. Some evidence of a predator-parasite mutualism was reported from spotted deer or chital (Axix axis as a prey species, dhole or Indian wild-dog (Cuon alpinus as the predator and a protozoan (Sarcocystis axicuonis as the parasite. We examine here, with the help of a model, the ecological conditions necessary for the evolution and stability of such a mutualistic relationship. A two – level game theory model was designed in which the payoff of a parasite is decided not only by alternative parasite strategies but also by alternative host strategies and vice versa. Conditions for ESS were examined. Results A tolerant predator strategy and a low or moderately virulent parasite strategy which together constitute mutualism are stable only at a high frequency of recycling of parasite and a substantial prey – capture benefit to the predator. Unlike the preliminary expectation, parasite will not evolve towards reduced virulence, but reach an optimum moderate level of virulence. Conclusion The available data on the behavioral ecology of dhole and chital suggest that they are likely to meet the stability criteria and therefore a predator-parasite mutualism can be stable in this system. The model also points out the gaps in the current data and could help directing further empirical work.

  9. Genomics and museum specimens. (United States)

    Nachman, Michael W


    Nearly 25 years ago, Allan Wilson and colleagues isolated DNA sequences from museum specimens of kangaroo rats (Dipodomys panamintinus) and compared these sequences with those from freshly collected animals (Thomas et al. 1990). The museum specimens had been collected up to 78 years earlier, so the two samples provided a direct temporal comparison of patterns of genetic variation. This was not the first time DNA sequences had been isolated from preserved material, but it was the first time it had been carried out with a population sample. Population geneticists often try to make inferences about the influence of historical processes such as selection, drift, mutation and migration on patterns of genetic variation in the present. The work of Wilson and colleagues was important in part because it suggested a way in which population geneticists could actually study genetic change in natural populations through time, much the same way that experimentalists can do with artificial populations in the laboratory. Indeed, the work of Thomas et al. (1990) spawned dozens of studies in which museum specimens were used to compare historical and present-day genetic diversity (reviewed in Wandeler et al. 2007). All of these studies, however, were limited by the same fundamental problem: old DNA is degraded into short fragments. As a consequence, these studies mostly involved PCR amplification of short templates, usually short stretches of mitochondrial DNA or microsatellites. In this issue, Bi et al. (2013) report a breakthrough that should open the door to studies of genomic variation in museum specimens. They used target enrichment (exon capture) and next-generation (Illumina) sequencing to compare patterns of genetic variation in historic and present-day population samples of alpine chipmunks (Tamias alpinus) (Fig. 1). The historic samples came from specimens collected in 1915, so the temporal span of this comparison is nearly 100 years.

  10. Snowdrops falling slowly into place: an improved phylogeny for Galanthus (Amaryllidaceae). (United States)

    Rønsted, Nina; Zubov, Dimitri; Bruun-Lund, Sam; Davis, Aaron P


    Snowdrops (Galanthus, 20 spp.; Amaryllidaceae) are cherished garden plants and the world's most traded wild-sourced ornamental bulb genus. Despite their popularity and economic importance, species delimitation is problematic and the infrageneric classification uncertain. We present a molecular phylogenetic study of Galanthus with the aim of resolving these issues and to better understand the evolution within the genus. Sequences of nuclear encoded nrITS, and plastid encoded matK, trnLF, ndhF, and psbK-psbI, for all currently recognised species and two naturally occurring putative hybrids, were analysed using maximum parsimony and Bayesian inference. Phylogenetic analysis of Galanthus, based on nuclear ITS sequences, provides a well-resolved topology, including seven well-supported named clades (platyphyllus, trojanus, ikariae, elwesii, nivalis, woronowii, and alpinus), and five major clades (A-E). The recovered ITS topology is in accordance with the geographical distribution of Galanthus species. The combined plastid data set provided far less resolution than that of ITS, with generally lower levels of statistical support, and one case of significant incongruence with the ITS dataset (involving G. gracilis). Phylogenetic network and hybridization analyses identified several possible hybridization events but these are more likely to be due to the result of a lack of resolution in the plastid dataset. The putative natural hybrid, G. ×valentinei nothosubsp. subplicatus, is supported by our data and analyses, whereas a hybrid origin for G. ×allenii is not. ITS and plastid data indicated that some Galanthus species are in need of taxonomic recircumscription.

  11. Forestry practices and aquatic biodiversity: Fish (United States)

    Gresswell, Robert E.


    In the Pacific Northwest, fish communities are found in a diverse array of aquatic habitats ranging from the large coastal rivers of the temperate rainforests, to the fragmented and sometimes ephemeral streams of the xeric interior basins, and high-elevation streams and lakes in the mountainous areas (Rieman et al. 2003). Only high-elevation lakes and streams isolated above barriers to fish passage remained historically devoid of fish because they were never invaded following Pleistocene glaciation (Smith 1981). Despite this widespread distribution and once great population abundances, taxonomic diversity of fishes in these forested systems is naturally lower than in aquatic habitats in the eastern U.S. (Reeves, Bisson, and Dambacher 1998). Interactions among factors that influence species richness in aquatic systems (e.g., basin size, long-term stability of habitat, and barriers to colonization; Smith 1981) continue to influence the occurrence and persistence of fishes in these systems today. Consequently, the larger low-elevation rivers and estuaries support the greatest variety of fish species. In the high-elevation tributary streams, fish communities are less complex because these aquatic systems were less climatically and geologically stable, and fish populations were smaller and more prone to local extirpation. Furthermore, barriers to fish passage inhibited dispersal and colonization (Smith 1981). Streams in forested landscapes generally support salmon and trout, Oncorhynchus spp., whitefish Prosopium spp., sculpins Cottus spp., suckers Catostomus spp., and minnows (Cyprinidae), but in some of the colder streams, chars (e.g., Salvelinus confluentus and Salvelinus malma) and lampreys (Petromyzontidae)may also occur (Rieman et al. 2003).Although biodiversity defined in terms of fish species richness is low in the Pacific Northwest, intraspecific variability is high, and polytypic fish species are common in the diverse aquatic habitats of the region. For

  12. Kalispel Non-Native Fish Suppression Project 2007 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Wingert, Michele; Andersen, Todd [Kalispel Natural Resource Department


    Non-native salmonids are impacting native salmonid populations throughout the Pend Oreille Subbasin. Competition, hybridization, and predation by non-native fish have been identified as primary factors in the decline of some native bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarki lewisi) populations. In 2007, the Kalispel Natural Resource Department (KNRD) initiated the Kalispel Nonnative Fish Suppression Project. The goal of this project is to implement actions to suppress or eradicate non-native fish in areas where native populations are declining or have been extirpated. These projects have previously been identified as critical to recovering native bull trout and westslope cutthroat trout (WCT). Lower Graham Creek was invaded by non-native rainbow (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis) after a small dam failed in 1991. By 2003, no genetically pure WCT remained in the lower 700 m of Graham Creek. Further invasion upstream is currently precluded by a relatively short section of steep, cascade-pool stepped channel section that will likely be breached in the near future. In 2008, a fish management structure (barrier) was constructed at the mouth of Graham Creek to preclude further invasion of non-native fish into Graham Creek. The construction of the barrier was preceded by intensive electrofishing in the lower 700 m to remove and relocate all captured fish. Westslope cutthroat trout have recently been extirpated in Cee Cee Ah Creek due to displacement by brook trout. We propose treating Cee Cee Ah Creek with a piscicide to eradicate brook trout. Once eradication is complete, cutthroat trout will be translocated from nearby watersheds. In 2004, the Washington Department of Fish and Wildlife (WDFW) proposed an antimycin treatment within the subbasin; the project encountered significant public opposition and was eventually abandoned. However, over the course of planning this 2004 project, little public

  13. Virulence of Renibacterium salmoninarum to salmonids (United States)

    Starliper, C.E.; Smith, D.R.; Shatzer, T.


    Virulence of Renibacterium salmoninarum isolates representing five origins was evaluated in eight salmonid hosts; four origins were of Lake Michigan and the fifth was of the Pacific Northwest. The species type strain, ATCC (American Type Culture Collection) 33209, was also included. Each isolate was grown in a kidney disease medium (KDM2) supplemented with 1 % ATCC 33209 culture metabolite; serial 10-fold dilutions were prepared, and groups of fish were challenged by intraperitoneal injection with 0.1 mL of each dilution. A 70-d observation period followed, and bacterial kidney disease (BKD) was diagnosed by the fluorescent antibody technique. Virulence of isolates was quantified as a dose lethal to 50% of fish (LD50) for each host–isolate challenge. In the first set of experiments, 23 isolates were used to challenge groups of brook trout Salvelinus fontinalis. The mean LD50 was 1.087 x 106 colony-forming units per milliliter (cfu/mL; SD = 2.022 x 106), and the LD50 values ranged from 8.457 x 106 to 2.227 x 104 cfu/mL. Analysis of variance to evaluate the effect of isolate origin on virulence in brook trout revealed no significant difference (F = 1.502; P = 0.243). Susceptibilities of the other salmonid hosts were evaluated by challenge with six isolates of R. salmoninarum representing each origin and the species type strain. For many of the host–isolate challenge combinations, time to death was highly dependent on the dilution (number of bacteria) injected. In general, the isolates MCO4M, B26, and A34 (all of Lake Michigan origin) tended to be more virulent. Also, LD50 values were dispersed throughout a wider range among the more susceptible hosts. Lake trout Salvelinus namaycush, rainbow trout Oncorhynchus mykiss, and brook trout were relatively resistant to challenge with the strains, whereas coho salmon O. kisutch, domestic Atlantic salmon Saltno salar, and chinook salmon O. tshawytscha were relatively susceptible. Another challenge evaluated the effect of

  14. A Comparative Assessment of Hydroponically Grown Cereal Crops for the Purification of Aquaculture Wastewater and the Production of Fish Feed

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    A. M. Snow


    Full Text Available Hydroponically grown wheat, barley and oats were examined for their ability to remove nutrients from aquaculture wastewater. Wheat, barley and oats seeds were germinated in water in a hydroponics system. The seedlings then received wastewater from an aquaculture system stocked with Arctic charr. During the experiment, the crops grew rapidly and fairly uniformly and showed no signs of mineral deficiency although fungal growth was evident. The average crop heights and yields at harvest were 19.0, 25.5 and 25.2 cm and 64, 59 and 42 t ha-1 for wheat, barley and oats, respectively. The hydroponically grown wheat, barley and oats were able to significantly reduce the pollution load of the aquaculture wastewater. The TS, COD, NH4+-N, NO2--N, NO3--N and PO43--P reductions ranged from 53.3 to 57.7%, from 55.7 to 78.7%, from 76.0 to 80.0% from 85.1 to 92.9%, from 62.1 to 79.3% and from 74.1 to 93.0%, respectively. The compartments containing barley produced the highest quality effluent, which was suitable for reuse in aquaculture operations. The average TS, COD, NH4+-N, NO2--N, NO3--N and PO43--P concentrations and pH of the final effluent from the compartments containing barley were 442, 64, 0.50, 0.02, 5.89 and 0.61 mg L-1 and 6.65, respectively. The nutritive value of the three wastewater grown crops was assessed to determine the suitability of using the plants as a component in fish feed. The three terrestrial crops meet the energy, fat, Ca, Mg, P, Na, S and Mn dietary requirements of aquatic animals, exceed the carbohydrate, crude fiber, Cl, K, Cu, Fe, Se and Zn requirements of fish and shellfish and do not contain sufficient amounts of protein to meet the dietary requirements of fish and shellfish. The crops will require supplementation with a high protein source that contains low concentrations of carbohydrates, crude fiber, Cl, K, Cu, Fe, Se and Zn. Common protein sources that could be used for supplementation included fishmeal, bone meal and

  15. Eight hundred years of environmental changes in a high Alpine lake (Gossenköllesee, Tyrol inferred from sediment records

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    Roland PSENNER


    Full Text Available Documentary and sediment records (diatoms, chrysophyte stomatocysts, plant pigments, carbon and nitrogen, metals and mineral magnetics were used to reconstruct environmental changes in the high alpine lake Gossenköllesee (Tyrol, Austria during the last 800 years. The records revealed complex interactions between human impact and climate. Gossenköllesee was predominantly influenced by land-use, which supplied nutrients to the lake. Documentary records report intensive sheep and cattle farming in the area around Gossenköllesee during medieval times. Pigments and chrysophyte stomatocysts indicated high nutrient concentrations prior to ca 1770 AD. First changes in land-use, however, were already detected ca 1670 AD. In 1675 AD the “Schwaighof” near Gossenköllesee, a perennial high altitude settlement, was sold to the Earl of Spaur, and farm management probably changed. After approx. 1770 AD in-lake production was reduced, indicating a decrease in land-use. According to historical records, the perennial settlement near Gossenköllesee was abandoned by at least 1890 AD. Gossenköllesee was also affected by fish stocking. Arctic charr (Salmo trutta morpha fario L. was introduced into the lake, most probably at the end of the 15th century. A decline in carbon, nitrogen and the pigments alloxanthin (cryptophytes and astaxanthin (grazers indicate a significant removal of grazers by fish. Superimposed on human activity, climate changes have also had a significant impact on Gossenköllesee. High productivity during the 12th century suggested by the plant pigment records might have been favoured by temperature increases, indicated by pronounced glacier retreats which began during the 10th/11th century. The “Schwaighof” near Gossenköllesee was sold to the Earl of Spaur when winter temperatures declined substantially in the 1670s. Changes in C/N ratio, iron, manganese and mineral magnetics indicated increased detrital input from the catchment

  16. Predicting aquatic macrophyte occurrence in soft-water oligotrophic lakes (Pyrenees mountain range

    Directory of Open Access Journals (Sweden)

    Cristina Pulido


    Full Text Available Distribution of aquatic macrophytes in lakes is related to geographical, morphological, catchment and water chemistry variables as well as human impacts, which modify the original environment. Here, we aim at building statistical models to establish the ecological niches of 11 aquatic macrophytes (10 different phanerogams and the genus Nitella from oligotrophic soft-water lakes and infer their ecological requirements and environmental constraints at the southernmost limit of their distribution. Macrophyte occurrence and environmental variables were obtained from 86 non-exploited oligotrophic soft-water lakes from the Pyrenees (Southern Europe; 42º50´N, 1º00´E; macrophytes inhabited 55 of these lakes. Optimum ranges and macrophyte occurrence were predicted in relation to 18 geographical, morphological, catchment and water chemistry variables using univariate and multivariate logistic models. Lakes at low altitude, in vegetated catchments and with low water concentration of NO3- and SO4-2, were the most suitable to host macrophytes. In general, individual species of aquatic macrophytes showed clear patterns of segregation along conductivity and pH gradients, although the specific combination of variables selected in the best models explaining their occurrence differed among species.  Based on the species response to pH and conductivity, we found Isoetes lacustris have its optimum in waters with low conductivity and pH (i.e. negative monotonic response. In contrast, Callitriche palustris, Ranunculus aquatilis, Subularia aquatica, Nitella spp., and Myriophyllum alterniflorum showed an optimum at intermediate values (i.e. unimodal response, whereas Potamogeton berchtoldii, Potamogeton alpinus, and Ranunculus trichophyllus as species had their optimum at relatively high water pH and conductivity (i.e. positive monotonic response. This pattern has been observed in other regions for the same species, although with different optima and tolerance

  17. The use of invertebrates as indicators of environmental change in alpine rivers and lakes

    Energy Technology Data Exchange (ETDEWEB)

    Khamis, K.; Hannah, D.M. [School of Geography Earth and Environmental Science, University of Birmingham, Birmingham B15 2TT (United Kingdom); Brown, L.E. [School of Geography/water@leeds, University of Leeds, Woodhouse Lane, Leeds LS2 9JT (United Kingdom); Tiberti, R. [DSTA, Dipartimento di Scienze della Terra e dell' Ambiente, University of Pavia, Via Ferrata 9, 27100 Pavia (Italy); Alpine Wildlife Research Centre, Gran Paradiso National Park, Degioz 11, I-1101 Valsavarenche, Aosta (Italy); Milner, A.M., E-mail: [School of Geography Earth and Environmental Science, University of Birmingham, Birmingham B15 2TT (United Kingdom); Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775 (United States)


    In alpine regions climatic change will alter the balance between water sources (rainfall, ice-melt, snowmelt, and groundwater) for aquatic systems, particularly modifying the relative contributions of meltwater, groundwater and rain to both rivers and lakes. While these changes are expected to have implications for alpine aquatic ecosystems, little is known about potential ecological tipping points and associated indicator taxa. We examined changes in biotic communities along a gradient of glacier influence for two study systems: (1) a stream network in the French Pyrénées; and (2) a network of lakes in the Italian Alps, with the aim of identifying potential indicator taxa (macroinvertebrates and zooplankton) of glacier retreat in these environments. To assess parallels in biotic responses across streams and lakes, both primary data and findings from other publications were synthesised. Using TITAN (Threshold Indicator Taxa ANalysis) changes in community composition of river taxa were identified at thresholds of < 5.1% glacier cover and < 66.6% meltwater contribution. Below these thresholds the loss of cold stenothermic benthic invertebrate taxa, Diamesa spp. and the Pyrenean endemic Rhyacophila angelieri was apparent. Some generalist taxa including Protonemura sp., Perla grandis, Baetis alpinus, Rhithrogena loyolaea and Microspectra sp. increased when glacier cover was < 2.7% and < 52% meltwater. Patterns were not as distinct for the alpine lakes, due to fewer sampling sites; however, Daphnia longispina grp. and the benthic invertebrate groups Plectopera and Planaria were identified as potential indicator taxa. While further work is required to assess potential indicator taxa for alpine lake systems, findings from alpine river systems were consistent between methods for assessing glacier influence (meltwater contribution/glacier cover). Hence, it is clear that TITAN could become a useful management tool, enabling: (i) the identification of taxa particularly

  18. Tósigos y antídotos en la literatura cervantina: Sobre los venenos en la España tardorrenacentista

    Directory of Open Access Journals (Sweden)

    F López-Muñoz


    Full Text Available Los textos cervantinos constituyen una interesante fuente para el estudio de la sociedad española tardorrenacentista. Nosotros hemos abordado las obras de Cervantes desde la óptica de la toxicología, analizando el uso de agentes tóxicos y venenosos, fundamentalmente alucinógenos y narcóticos en el ámbito de la práctica de la brujería y hechicería (ungüentos de brujas, filtros de amor, pócimas venenosas, etc., así como las menciones a las hipotéticas sustancias dotadas de acción alexifármaca, como la verbena (Verbena officinalis, el cuerno de unicornio, las piedras bezoares o el castóreo. Las obras cervantinas en las que se hace referencia a estos preparados son las novelas El Quijote, La Galatea, Viaje del Parnaso y cuatro Novelas Ejemplares (La española inglesa, El licenciado Vidriera, El celoso extremeño y El coloquio de los perros, así como en las comedias Pedro de Urdemalas, La entretenida y El laberinto del amor. Entre los agentes tóxicos de origen herbal citados expresamente por Cervantes en el contexto analizado se encuentran el beleño (Hyoscyamus niger / albus, el tabaco (Nicotiana tabacum, la adelfa (Nerium oleander, el tártago (Euphorbia lathyris, el ruibarbo (Rheum officinale, Rumex alpinus y, de forma enmascarada, el opio (Papaver somniferum. En relación con el resto de preparados dotados de actividad tóxica, Cervantes no identifica sus ingredientes, aunque, a tenor de la sintomatología descrita por el autor, podrían ser plantas de la familia de las solanáceas, como el beleño, el solano, la datura, la belladona o la mandrágora. Con respecto a los tóxicos minerales, únicamente hay referencias a los efectos del mercurio o azogue. El Dioscórides comentado por Andrés Laguna pudo ser la fuente técnica utilizada por Cervantes para documentarse en esta materia.

  19. Effects of lake trout refuges on lake whitefish and cisco in the Apostle Islands Region of Lake Superior (United States)

    Zuccarino-Crowe , Chiara M.; Taylor, William W.; Hansen, Michael J.; Seider, Michael J.; Krueger, Charles C.


    Lake trout refuges in the Apostle Islands region of Lake Superior are analogous to the concept of marine protected areas. These refuges, established specifically for lake trout (Salvelinus namaycush) and closed to most forms of recreational and commercial fishing, were implicated as one of several management actions leading to successful rehabilitation of Lake Superior lake trout. To investigate the potential significance of Gull Island Shoal and Devils Island Shoal refuges for populations of not only lake trout but also other fish species, relative abundances of lake trout, lake whitefish (Coregonus clupeaformis), and cisco (Coregonus artedi) were compared between areas sampled inside versus outside of refuge boundaries. During 1982–2010, lake trout relative abundance was higher and increased faster inside the refuges, where lake trout fishing was prohibited, than outside the refuges. Over the same period, lake whitefish relative abundance increased faster inside than outside the refuges. Both evaluations provided clear evidence that refuges protected these species. In contrast, trends in relative abundance of cisco, a prey item of lake trout, did not differ significantly between areas inside and outside the refuges. This result did not suggest indirect or cascading refuge effects due to changes in predator levels. Overall, this study highlights the potential of species-specific refuges to benefit other fish species beyond those that were the refuges' original target. Improved understanding of refuge effects on multiple species of Great Lakes fishes can be valuable for developing rationales for refuge establishment and predicting associated fish community-level effects.

  20. Can pelagic forage fish and spawning cisco (Coregonus artedi) biomass in the western arm of Lake Superior be assessed with a single summer survey? (United States)

    Yule, D.L.; Stockwell, J.D.; Schreiner, D.R.; Evrard, L.M.; Balge, M.; Hrabik, T.R.


    Management efforts to rehabilitate lake trout Salvelinus namaycush in Lake Superior have been successful and the recent increase in their numbers has led to interest in measuring biomass of pelagic prey fish species important to these predators. Lake Superior cisco Coregonus artedi currently support roe fisheries and determining the sustainability of these fisheries is an important management issue. We conducted acoustic and midwater trawl surveys of the western arm of Lake Superior during three periods: summer (July-August), October, and November 2006 to determine if a single survey can be timed to estimate biomass of both prey fish and spawning cisco. We evaluated our methods by comparing observed trawl catches of small (cisco increased substantially in November, while small bloater Coregonus hoyi biomass was lower. We compared our summer 2006 estimates of total fish biomass to the results of a summer survey in 1997 and obtained similar results. We conclude that the temporal window for obtaining biomass estimates of pelagic prey species in the western arm of Lake Superior is wide (July through October), but estimating spawning cisco abundance is best done with a November survey.

  1. Conservation genetics of Lake Superior brook trout: Issues, questions, and directions (United States)

    Wilson, C.C.; Stott, W.; Miller, L.; D'Amelio, S.; Jennings, Martin J.; Cooper, A.M.


    Parallel efforts by several genetic research groups have tackled common themes relating to management concerns about and recent rehabilitation opportunities for coaster brook trout Salvelinus fontinalis in Lake Superior. The questions that have been addressed include the evolutionary and genetic status of coaster brook trout, the degree of relatedness among coaster populations and their relationship to riverine tributary brook trout populations, and the role and effectiveness of stocking in maintaining and restoring coasters to Lake Superior. Congruent genetic results indicate that coasters are an ecotype (life history variant) rather than an evolutionarily significant unit or genetically distinct strain. Regional structure exists among brook trout stocks, coasters being produced from local populations. Introgression of hatchery genes into wild populations appears to vary regionally and may relate to local population size, habitat integrity, and anthropogenic pressures. Tracking the genetic diversity and integrity associated with captive breeding programs is helping to ensure that the fish used for stocking are representative of their source populations and appropriate for rehabilitation efforts. Comparative analysis of shared samples among collaborating laboratories is enabling standardization of genotype scoring and interpretation as well as the development of a common toolkit for assessing genetic structure and diversity. Incorporation of genetic data into rehabilitation projects will facilitate monitoring efforts and subsequent adaptive management. Together, these multifaceted efforts provide comprehensive insights into the biology of coaster brook trout and enhance restoration options. ?? Copyright by the American Fisheries Society 2008.

  2. Lake trout in northern Lake Huron spawn on submerged drumlins (United States)

    Riley, Stephen C.; Binder, Thomas; Wattrus, Nigel J.; Faust, Matthew D.; Janssen, John; Menzies, John; Marsden, J. Ellen; Ebener, Mark P.; Bronte, Charles R.; He, Ji X.; Tucker, Taaja R.; Hansen, Michael J.; Thompson, Henry T.; Muir, Andrew M.; Krueger, Charles C.


    Recent observations of spawning lake trout Salvelinus namaycush near Drummond Island in northern Lake Huron indicate that lake trout use drumlins, landforms created in subglacial environments by the action of ice sheets, as a primary spawning habitat. From these observations, we generated a hypothesis that may in part explain locations chosen by lake trout for spawning. Most salmonines spawn in streams where they rely on streamflows to sort and clean sediments to create good spawning habitat. Flows sufficient to sort larger sediment sizes are generally lacking in lakes, but some glacial bedforms contain large pockets of sorted sediments that can provide the interstitial spaces necessary for lake trout egg incubation, particularly if these bedforms are situated such that lake currents can penetrate these sediments. We hypothesize that sediment inclusions from glacial scavenging and sediment sorting that occurred during the creation of bedforms such as drumlins, end moraines, and eskers create suitable conditions for lake trout egg incubation, particularly where these bedforms interact with lake currents to remove fine sediments. Further, these bedforms may provide high-quality lake trout spawning habitat at many locations in the Great Lakes and may be especially important along the southern edge of the range of the species. A better understanding of the role of glacially-derived bedforms in the creation of lake trout spawning habitat may help develop powerful predictors of lake trout spawning locations, provide insight into the evolution of unique spawning behaviors by lake trout, and aid in lake trout restoration in the Great Lakes.

  3. Movement patterns of Brook Trout in a restored coastal stream system in southern Massachusetts (United States)

    Snook, Erin L.; Letcher, Benjamin H.; Dubreuil, Todd L.; Zydlewski, Joseph; O'Donnell, Matthew J.; Whiteley, Andrew R.; Hurley, Stephen T.; Danylchuk, Andy J.


    Coastal Brook Trout (Salvelinus fontinalis) populations are found from northern Canada to New England. The extent of anadromy generally decreases with latitude, but the ecology and movements of more southern populations are poorly understood. We conducted a 33-month acoustic telemetry study of Brook Trout in Red Brook, MA, and adjacent Buttermilk Bay (marine system) using 16 fixed acoustic receivers and surgically implanting acoustic transmitters in 84 individuals. Tagged Brook Trout used the stream, estuary (50% of individuals) and bay (10% of individuals). Movements into full sea water were brief when occurring. GAMM models revealed that transitions between habitat areas occurred most often in spring and fall. Environmental data suggest that use of the saline environment is limited by summer temperatures in the bay. Movements may also be related to moon phase. Compared to more northern coastal populations of Brook Trout, the Red Brook population appears to be less anadromous overall, yet the estuarine segment of the system may have considerable ecological importance as a food resource.

  4. Xenobiotic-induced apoptosis: significance and potential application as a general biomarker of response (United States)

    Sweet, Leonard I.; Passino-Reader, Dora R.; Meier, Peter G.; Omann, Geneva M.


    The process of apoptosis, often coined programmed cell death, involves cell injury induced by a variety of stimuli including xenobiotics and is morphologically, biochemically, and physiologically distinct from necrosis. Apoptotic death is characterized by cellular changes such as cytoplasm shrinkage, chromatin condensation, and plasma membrane asymmetry. This form of cell suicide is appealing as a general biomarker of response in that it is expressed in multiple cell systems (e.g. immune, neuronal, hepatal, intestinal, dermal, reproductive), is conserved phylogenetically (e.g. fish, rodents, birds, sheep, amphibians, roundworms, plants, humans), is modulated by environmentally relevant levels of chemical contaminants, and indicates a state of stress of the organism. Further, apoptosis is useful as a biomarker as it serves as a molecular control point and hence may provide mechanistic information on xenobiotic stress. Studies reviewed here suggest that apoptosis is a sensitive and early indicator of acute and chronic chemical stress, loss of cellular function and structure, and organismal health. Examples are provided of the application of this methodology in studies of health of lake trout (Salvelinus namaycush) in the Laurentian Great Lakes.

  5. Comparative hatchability of lake trout eggs differing in contaminant burden and incubation conditions (United States)

    Mac, M.J.; Berlin, W.H.; Rottiers, D.V.


    In 1972, fertilized eggs of lake trout (Salvelinus namaycush) from the Marquette (Michigan) State Fish Hatchery (where levels of contaminants are relatively low) and eggs from lake trout collected in Michigan waters of Lake Michigan near Saugatuck and Charlevoix (where levels of PCB's and DDE are elevated) were incubated at hatchery temperatures (6° C) and at temperatures simulating the natural temperature cycle of Lake Michigan (1-8° C). Survival to yolk absorption of larvae from these three sources ranged from 40.3 to 65.5%, and no correlation was observed between survival and the level of PCB's and DDE in the eggs. Additional studies in 1975 with lake trout eggs from the same three sources confirmed previous observations that the elevated levels of PCB's and DDE in eggs from Lake Michigan did not appear to affect the percent hatch of lake trout eggs or survival of the fry to the swim-up stage. When fry hatched from eggs with an elevated contaminant burden were starved for several weeks, we observed no abnormal increase in posthatching mortality during the period when the yolk stores were being consumed.

  6. Heritage strain and diet of wild young of year and yearling lake trout in the main basin of Lake Huron (United States)

    Roseman, E.F.; Stott, W.; O'Brien, T. P.; Riley, S.C.; Schaeffer, J.S.


    Restoration of lake trout Salvelinus namaycush stocks in Lake Huron is a fish community objective developed to promote sustainable fish communities in the lake. Between 1985 and 2004, 12.65 million lake trout were stocked into Lake Huron representing eight different genetic strains. Collections of bona fide wild fish in USGS surveys have increased in recent years and this study examined the ancestry and diet of fish collected between 2004 and 2006 to explore the ecological role they occupy in Lake Huron. Analysis of microsatellite DNA revealed that both pure strain and inter-strain hybrids were observed, and the majority of fish were classified as Seneca Lake strain or Seneca Lake hybrids. Diets of 50 wild age-0 lake trout were examined. Mysis, chironomids, and zooplankton were common prey items of wild age-0 lake trout. These results indicate that stocked fish are successfully reproducing in Lake Huron indicating a level of restoration success. However, continued changes to the benthic macroinvertebrate community, particularly declines of Mysis, may limit growth and survival of wild fish and hinder restoration efforts.

  7. Marcellus and mercury: Assessing potential impacts of unconventional natural gas extraction on aquatic ecosystems in northwestern Pennsylvania. (United States)

    Grant, Christopher J; Weimer, Alexander B; Marks, Nicole K; Perow, Elliott S; Oster, Jacob M; Brubaker, Kristen M; Trexler, Ryan V; Solomon, Caroline M; Lamendella, Regina


    Mercury (Hg) is a persistent element in the environment that has the ability to bioaccumulate and biomagnify up the food chain with potentially harmful effects on ecosystems and human health. Twenty-four streams remotely located in forested watersheds in northwestern PA containing naturally reproducing Salvelinus fontinalis (brook trout), were targeted to gain a better understanding of how Marcellus shale natural gas exploration may be impacting water quality, aquatic biodiversity, and Hg bioaccumulation in aquatic ecosystems. During the summer of 2012, stream water, stream bed sediments, aquatic mosses, macroinvertebrates, crayfish, brook trout, and microbial samples were collected. All streams either had experienced hydraulic fracturing (fracked, n = 14) or not yet experienced hydraulic fracturing (non-fracked, n = 10) within their watersheds at the time of sampling. Analysis of watershed characteristics (GIS) for fracked vs non-fracked sites showed no significant differences (P > 0.05), justifying comparisons between groups. Results showed significantly higher dissolved total mercury (FTHg) in stream water (P = 0.007), lower pH (P = 0.033), and higher dissolved organic matter (P = 0.001) at fracked sites. Total mercury (THg) concentrations in crayfish (P = 0.01), macroinvertebrates (P = 0.089), and predatory macroinvertebrates (P = 0.039) were observed to be higher for fracked sites. A number of positive correlations between amount of well pads within a watershed and THg in crayfish (r = 0.76, P shale natural gas exploration is having an effect on aquatic ecosystems.

  8. Fish dispersal in fragmented landscapes: a modeling framework for quantifying the permeability of structural barriers. (United States)

    Pépino, Marc; Rodríguez, Marco A; Magnan, Pierre


    Dispersal is a key determinant of the spatial distribution and abundance of populations, but human-made fragmentation can create barriers that hinder dispersal and reduce population viability. This study presents a modeling framework based on dispersal kernels (modified Laplace distributions) that describe stream fish dispersal in the presence of obstacles to passage. We used mark-recapture trials to quantify summer dispersal of brook trout (Salvelinus fontinalis) in four streams crossed by a highway. The analysis identified population heterogeneity in dispersal behavior, as revealed by the presence of a dominant sedentary component (48-72% of all individuals) characterized by short mean dispersal distance (dispersal distance (56-1086 m). We did not detect evidence of barrier effects on dispersal through highway crossings. Simulation of various plausible scenarios indicated that detectability of barrier effects was strongly dependent on features of sampling design, such as spatial configuration of the sampling area, barrier extent, and sample size. The proposed modeling framework extends conventional dispersal kernels by incorporating structural barriers. A major strength of the approach is that ecological process (dispersal model) and sampling design (observation model) are incorporated simultaneously into the analysis. This feature can facilitate the use of prior knowledge to improve sampling efficiency of mark-recapture trials in movement studies. Model-based estimation of barrier permeability and its associated uncertainty provides a rigorous approach for quantifying the effect of barriers on stream fish dispersal and assessing population dynamics of stream fish in fragmented landscapes.

  9. Genetic identity of brook trout in Lake Superior south shore streams: Potential for genetic monitoring of stocking and rehabilitation efforts (United States)

    Sloss, Brian L.; Jennings, Martin J.; Franckowiak, R.; Pratt, D.M.


    Rehabilitation of migratory ('coaster') brook trout Salvelinus fontinalis along Lake Superior's south shore is a topic of high interest among resource stakeholders and management agencies. Proposed strategies for rehabilitation of this brook trout life history variant in Wisconsin include supplemental stocking, watershed management, habitat rehabilitation, harvest regulations, or a combination thereof. In an effort to evaluate the success of coaster brook trout rehabilitation efforts, we collected genetic data from four populations of interest (Whittlesey Creek, Bois Brule River, Bark River, and Graveyard Creek) and the hatchery sources used in the Whittlesey Creek supplementation experiment. We characterized the genetic diversity of 30 individuals from each of four populations using 13 microsatellite DNA loci. Levels of genetic variation were consistent with those in similar studies conducted throughout the basin. Significant genetic variation among the populations was observed, enabling adequate population delineation through assignment tests. Overall, 208 of the 211 sampled fish (98.6%) were correctly assigned to their population of origin. Simulated F1 hybrids between two hatchery strains and the Whittlesey Creek population were identifiable in the majority of attempts (90.5-100% accuracy with 0-2.5% error). The genetic markers and analytical techniques described provide the ability to monitor the concurrent coaster brook trout rehabilitation efforts along Wisconsin's Lake Superior south shore, including the detection of hybridization between hatchery and native populations. ?? Copyright by the American Fisheries Society 2008.

  10. Marine Habitat Use by Anadromous Bull Trout from the Skagit River, Washington (United States)

    Hayes, Michael C.; Rubin, Steve P.; Reisenbichler, Reginald; Goetz, Fred A.; Jeanes, Eric; McBride, Aundrea


    Acoustic telemetry was used to describe fish positions and marine habitat use by tagged bull trout Salvelinus confluentus from the Skagit River, Washington. In March and April 2006, 20 fish were captured and tagged in the lower Skagit River, while 15 fish from the Swinomish Channel were tagged during May and June. Sixteen fish tagged in 2004 and 2005 were also detected during the study. Fish entered Skagit Bay from March to May and returned to the river from May to August. The saltwater residency for the 13 fish detected during the out-migration and return migration ranged from 36 to 133 d (mean ± SD, 75 ± 22 d). Most bull trout were detected less than 14 km (8.5 ± 4.4 km) from the Skagit River, and several bay residents used the Swinomish Channel while migrating. The bull trout detected in the bay were associated with the shoreline (distance from shore, 0.32 ± 0.27 km) and occupied shallow-water habitats (mean water column depth, Zostera sp.) vegetation classes made up more than 70% of the area used by bull trout. Our results will help managers identify specific nearshore areas that may require further protection to sustain the unique anadromous life history of bull trout.

  11. Demographic characteristics of an adfluvial bull trout population in Lake Pend Oreille, Idaho (United States)

    McCubbins, Jonathan L; Hansen, Michael J.; DosSantos, Joseph M; Dux, Andrew M


    Introductions of nonnative species, habitat loss, and stream fragmentation have caused the Bull Trout Salvelinus confluentus to decline throughout much of its native distribution. Consequently, in June 1998, the Bull Trout was listed under the U.S. Endangered Species Act as threatened. The Bull Trout has existed in Lake Pend Oreille and its surrounding tributaries since the last ice age, and the lake once supported a world-renowned Bull Trout fishery. To quantify the current status of the Bull Trout population in Lake Pend Oreille, Idaho, we compared the mean age, growth, maturity, and abundance with reports in a study conducted one decade earlier. Abundance was estimated by mark–recapture for Bull Trout caught in trap nets and gill nets set in Lake Pend Oreille during ongoing suppression netting of Lake Trout S. namaycushin 2007–2008. Bull Trout sampled in 2006–2008 were used to estimate age structure, survival, growth, and maturity. Estimated Bull Trout abundance was similar to that estimated one decade earlier in Lake Pend Oreille. Bull Trout residing in Lake Pend Oreille between 2006 and 2008 were between ages 4 and 14 years; their growth was fastest between ages 1 and 2 and slowed thereafter. Male and female Bull Trout matured at a similar age, but females grew faster than males, thereby maturing at a larger size. Our findings suggest that management has effectively addressed current threats to increase the likelihood of long-term persistence of the Bull Trout population in Lake Pend Oreille.

  12. Assessing the feasibility of native fish reintroductions: a framework applied to threatened bull trout (United States)

    Dunham, Jason B.; Gallo, Kirsten; Shively, Dan; Allen, Chris; Goehring, Brad


    Translocations to recover native fishes have resulted in mixed success. One reason for the failure of these actions is inadequate assessments of their feasibility prior to implementation. Here, we provide a framework developed to assess the feasibility of one type of translocation-reintroduction. The framework was founded on two simple components of feasibility: the potential for recipient habitats to support a reintroduction and the potential of available donor populations to support a reintroduction. Within each component, we developed a series of key questions. The final assessment was based on a scoring system that incorporated consideration of uncertainty in available information. The result was a simple yet transparent system for assessing reintroduction feasibility that can be rapidly applied in practice. We applied this assessment framework to the potential reintroduction of threatened bull trout Salvelinus confluentus into the Clackamas River, Oregon. In this case, the assessment suggested that the degree of feasibility for reintroduction was high based on the potential of recipient habitats and available donor populations. The assessment did not provide a comprehensive treatment of all possible factors that would drive an actual decision to implement a reintroduction,

  13. Spawning and rearing behavior of bull trout in a headwaterlake ecosystem (United States)

    Lora B. Tennant,; Gresswell, Bob; Guy, Christopher S.; Michael H. Meeuwig,


    Numerous life histories have been documented for bull trout Salvelinus confluentus. Lacustrine-adfluvial bull trout populations that occupy small, headwater lake ecosystems and migrate short distances to natal tributaries to spawn are likely common; however, much of the research on potamodromous bull trout has focused on describing the spawning and rearing characteristics of bull trout populations that occupy large rivers and lakes and make long distance spawning migrations to natal headwater streams. This study describes the spawning and rearing characteristics of lacustrine-adfluvial bull trout in the Quartz Lake drainage, Glacier National Park, USA, a small headwater lake ecosystem. Many spawning and rearing characteristics of bull trout in the Quartz Lake drainage are similar to potamodromous bull trout that migrate long distances. For example, subadult bull trout distribution was positively associated with slow-water habitat unit types and maximum wetted width, and negatively associated with increased stream gradient. Bull trout spawning also occurred when water temperatures were between 5 and 9 °C, and redds were generally located in stream segments with low stream gradient and abundant gravel and cobble substrates. However, this study also elucidated characteristics of bull trout biology that are not well documented in the literature, but may be relatively widespread and have important implications regarding general characteristics of bull trout ecology, use of available habitat by bull trout, and persistence of lacustrine-adfluvial bull trout in small headwater lake ecosystems.

  14. Are brown trout replacing or displacing bull trout populations in a changing climate? (United States)

    Al-Chokhachy, Robert K.; Schmetterling, David A.; Clancy, Chris; Saffel, Pat; Kovach, Ryan; Nyce, Leslie; Liermann, Brad; Fredenberg, Wade A.; Pierce, Ron


    Understanding how climate change may facilitate species turnover is an important step in identifying potential conservation strategies. We used data from 33 sites in western Montana to quantify climate associations with native bull trout (Salvelinus confluentus) and non-native brown trout (Salmo trutta) abundance and population growth rates (λ). We estimated λ using exponential growth state space models and delineated study sites based on bull trout use for either Spawning and Rearing (SR) or Foraging, Migrating, and Overwintering (FMO) habitat. Bull trout abundance was negatively associated with mean August stream temperatures within SR habitat (r = -0.75). Brown trout abundance was generally highest at temperatures between 12 and 14°C. We found bull trout λ were generally stable at sites with mean August temperature below 10°C but significantly decreasing, rare, or extirpated at 58% of the sites with temperatures exceeding 10°C. Brown trout λ were highest in SR and sites with temperatures exceeding 12°C. Declining bull trout λs at sites where brown trout were absent suggests brown trout are likely replacing bull trout in a warming climate.

  15. Surficial substrates and bathymetry of five historical lake trout spawning reefs in near-shore waters of the Great Lakes (United States)

    Edsall, Thomas A.; Brown, Charles L.; Kennedy, Gregory W.; French, John R. P.


    The reestablishment of self-sustaining stocks of lake trout (Salvelinus namaycush) in the lower four Great Lakes has been substantially impeded because planted fish do not produce enough progeny that survive and reproduce. The causes for this failure are unknown, but many historical spawning sites of lake trout have been degraded by human activities and can no longer produce viable swim-up fry. In this study, we used side-scan sonar and an underwater video camera to survey, map, and evaluate the sustainability of one reef in each of the five Great Lakes for lake trout spawning and fry production. At four of the reef sites, we found good-to-excellent substrate for spawning and fry production by the shallow-water strains of lake trout that are now being planted. These substrates were in water 6-22 m deep and were composed largely of rounded or angular rubble and cobble. Interstitial spaces in these substrates were 20 cm or deeper and would protect naturally spawned eggs and fry from predators, ice scour, and buffeting by waves and currents. Subsequent studies of egg survival by other researchers confirmed our evaluation that the best substrates at two of these sites still have the potential to produce viable swim-up fry.

  16. Growth and survival of stocked lake trout with nuclear cataracts in Lake Ontario (United States)

    Kincaid, Harold L.; Elrod, Joseph H.


    Four strains of yearling lake trout Salvelinus namaycush from the 1985 and 1986 year-classes at the Allegheny National Fish Hatchery were evaluated for nuclear cataracts prior to stocking in Lake Ontario in June 1986 and 1987. Lake trout recaptured by bottom trawling from April to August 1987 and 1988 were examined for cataracts. Cataract frequencies in three strains of yearling lake trout at stocking in 1986 and after 14 and 26 months in the lake were: Seneca Lake–35, 24, and 29%; Lake Ontario–32,24, and 42%; and Lake Superior–7,4, and 6%. Cataract frequencies for yearlings at stocking in 1987 and after 2 and 14 months were: Seneca Lake–51, 37, and 51 %; Lake Superior–7,12, and 12%; and Jenny Lake–46,13, and 36%. Cataract frequency was lower (P weight and length were not different between healthy fish and fish with cataracts. The absence of growth depression in fish with cataracts and the reduced survival rate suggested that faster growing fish were more susceptible to cataract formation.

  17. Fisheries Enhancement on the Coeur d'Alene Indian Reservation; Hangman Creek, Annual Report 2001-2002.

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    Peters, Ronald; Kinkead, Bruce; Stanger, Mark


    Historically, Hangman Creek produced Chinook salmon (Oncorhynchus tshawytscha) and Steelhead trout (Oncorhynchus mykiss) for the Upper Columbia Basin Tribes. One weir, located at the mouth of Hangman Creek was reported to catch 1,000 salmon a day for a period of 30 days a year (Scholz et al. 1985). The current town of Tekoa, Washington, near the state border with Idaho, was the location of one of the principle anadromous fisheries for the Coeur d'Alene Tribe (Scholz et al. 1985). The construction, in 1909, of Little Falls Dam, which was not equipped with a fish passage system, blocked anadromous fish access to the Hangman Watershed. The fisheries were further removed with the construction of Chief Joseph and Grand Coulee Dams. As a result, the Coeur d'Alene Indian Tribe was forced to rely more heavily on native fish stocks such as Redband trout (Oncorhynchus mykiss gairdneri), Westslope Cutthroat trout (O. clarki lewisii), Bull trout (Salvelinus confluentus) and other terrestrial wildlife. Historically, Redband and Cutthroat trout comprised a great deal of the Coeur d'Alene Tribe's diet (Power 1997).

  18. Efficiency of Portable Antennas for Detecting Passive Integrated Transponder Tags in Stream-Dwelling Salmonids. (United States)

    Banish, Nolan P; Burdick, Summer M; Moyer, Katherine R


    Portable antennas have become an increasingly common technique for tracking fish marked with passive integrated transponder (PIT) tags. We used logistic regression to evaluate how species, fish length, and physical habitat characteristics influence portable antenna detection efficiency in stream-dwelling brown trout (Salmo trutta), bull trout (Salvelinus confluentus), and redband trout (Oncorhynchus mykiss newberrii) marked with 12-mm PIT tags. We redetected 56% (20/36) of brown trout, 34% (68/202) of bull trout, and 33% (20/61) of redband trout after a recovery period of 21 to 46 hours. Models indicate support for length and species and minor support for percent boulder, large woody debris, and percent cobble as parameters important for describing variation in detection efficiency, although 95% confidence intervals for estimates were large. The odds of detecting brown trout (1.5 ± 2.2 [mean ± SE]) are approximately four times as high as bull trout (0.4 ± 1.6) or redband trout (0.3 ± 1.8) and species-specific differences may be related to length. Our reported detection efficiency for brown trout falls within the range of other studies, but is the first reported for bull trout and redband trout. Portable antennas may be a relatively unbiased way of redetecting varying sizes of all three salmonid species.

  19. Parasites of the deepwater sculpin (Myoxocephalus thompsonii) across its Canadian range. (United States)

    Carney, Joseph P; Sheldon, Tom A; Lovejoy, Nathan R


    Deepwater sculpin (Myoxocephalus thompsonii) were collected from 19 lakes across the species' distribution in Canada and examined for parasites. Six helminth species (Crepidostomum farionis, Bothriocephalus cuspidatus, Proteocephalus sp., Cyathocephalus truncatus, Raphidascaris acus, and Echinorhynchus salmonis), 1 crustacean species (Ergasilus nerkae), and 1 molluscan species (glochidia) parasitized these hosts. Crepidostomum farionis, Proteocephalus sp., R. acus, E. nerkae, and the glochidia represent new parasite records for this host species. Overall parasite prevalence was 78.0% while mean intensity was 6.1 +/- 7.1 SD. Bothriocephalus cuspidatus was the most prevalent parasite and was recorded from 62.2% of the deepwater sculpin and found in 17 of the 19 lakes. The low-productivity habitat of this host limits the parasites available for transmission, and the infra- and component communities were generally species poor. With the exception of the Proteocephalus sp., all of the helminth parasites recovered have been reported as adults in lake trout (Salvelinus namaycush) or burbot (Lota lota), suggesting that, in the lakes where they occur, deepwater sculpin may play an important role in energetic transfer and parasitic transmission to higher trophic levels.

  20. Hydrological response to timber harvest in northern Idaho: Implications for channel scour and persistence of salmonids (United States)

    Tonina, D.; Luce, C.H.; Rieman, B.; Buffington, J.M.; Goodwin, P.; Clayton, S.R.; Ali, S. Md; Barry, J.J.; Berenbrock, C.


    The potential for forest harvest to increase snowmelt rates in maritime snow climates is well recognized. However, questions still exist about the magnitude of peak flow increases in basins larger than 10 km2 and the geomorphic and biological consequences of these changes. In this study, we used observations from two nearly adjacent small basins (13 and 30 km2) in the Coeur d'Alene River basin, one with recent, relatively extensive, timber harvest, and the other with little disturbance in the last 50 years to explore changes in peak flows due to timber harvest and their potential effects on fish. Peak discharge was computed for a specitic rain-on-snow event using a series of physical models that linked predicted values of snowmelt input to a runoff-routing model. Predictions indicate that timber harvest caused a 25% increase in the peak flow of the modelled event and increased the frequency of events of this magnitude from a 9-year recurrence interval to a 3-6-year event. These changes in hydrologic regime, with larger discharges at shorter recurrence intervals, are predicted to increase the depth and frequency of streambed scour, causing up to 15% added mortality of bull trout (Salvelinus confluentus) embryos. Mortality from increased scour, although not catastrophic, may have contributed to the extirpation of this species from the Coeur d'Alene basin, given the widespread timber harvest that occurred in this region. Copyright ?? 2008 John Wiley & Sons, Ltd.

  1. Pacific salmon (Oncorhynchus spp.) runs and consumer fitness: growth and energy storage in stream-dwelling salmonids increase with salmon spawner density (United States)

    Rinella, Daniel J.; Wipfli, Mark S.; Stricker, Craig A.; Heintz, Ron A.; Rinella, Matthew J.


    We examined how marine-derived nutrients (MDN), in the form of spawning Pacific salmon, influenced the nutritional status and δ15N of stream-dwelling fishes. We sampled juvenile coho salmon (Oncorhynchus kisutch) and Dolly Varden (Salvelinus malma) during spring and fall from 11 south-central Alaskan streams that ranged widely in spawning salmon biomass (0.1–4.7 kg·m–2). Growth rate (as indexed by RNA–DNA ratios), energy density, and δ15N enrichment in spring-sampled fishes increased with spawner biomass, indicating the persistence of spawner effects more than 6 months after salmon spawning. Point estimates suggest that spawner effects on nutrition were substantially greater for coho salmon than Dolly Varden (268% and 175% greater for growth and energy, respectively), indicating that both species benefitted physiologically, but that juvenile coho salmon accrued more benefits than Dolly Varden. Although the data were less conclusive for fall- than spring-sampled fish, they do suggest spawner effects were also generally positive during fall, soon after salmon spawned. In a follow-up analysis where growth rate and energy density were modeled as a function of δ15N enrichment, results suggested that both increased with MDN assimilation, especially in juvenile coho salmon. Our results support the importance of salmon runs to the nutritional ecology of stream-dwelling fishes.

  2. Hydroacoustic estimates of abundance and spatial distribution of pelagic prey fishes in western Lake Superior (United States)

    Mason, Doran M.; Johnson, Timothy B.; Harvey, Chris J.; Kitchell, James F.; Schram, Stephen T.; Bronte, Charles R.; Hoff, MIchael H.; Lozano, Stephen J.; Trebitz, Anett S.; Schreiner, Donald R.; Lamon, E. Conrad; Hrabik, Thomas R.


    Lake herring (Coregonus artedi) and rainbow smelt (Osmerus mordax) are a valuable prey resource for the recovering lake trout (Salvelinus namaycush) in Lake Superior. However, prey biomass may be insufficient to support the current predator demand. In August 1997, we assessed the abundance and spatial distribution of pelagic coregonines and rainbow smelt in western Lake Superior by combining a 120 kHz split beam acoustics system with midwater trawls. Coregonines comprised the majority of the midwater trawl catches and the length distributions for trawl caught fish coincided with estimated sizes of acoustic targets. Overall mean pelagic prey fish biomass was 15.56 kg ha−1 with the greatest fish biomass occurring in the Apostle Islands region (27.98 kg ha−1), followed by the Duluth Minnesota region (20.22 kg ha−1), and with the lowest biomass occurring in the open waters of western Lake Superior (9.46 kg ha−1). Biomass estimates from hydroacoustics were typically 2–134 times greater than estimates derived from spring bottom trawl surveys. Prey fish biomass for Lake Superior is about order of magnitude less than acoustic estimates for Lakes Michigan and Ontario. Discrepancies observed between bioenergetics-based estimates of predator consumption of coregonines and earlier coregonine biomass estimates may be accounted for by our hydroacoustic estimates.

  3. Efficiency of portable antennas for detecting passive integrated transponder tags in stream-dwelling salmonids (United States)

    Banish, Nolan P.; Burdick, Summer M.; Moyer, Katherine R.


    Portable antennas have become an increasingly common technique for tracking fish marked with passive integrated transponder (PIT) tags. We used logistic regression to evaluate how species, fish length, and physical habitat characteristics influence portable antenna detection efficiency in stream-dwelling brown trout (Salmo trutta), bull trout (Salvelinus confluentus), and redband trout (Oncorhynchus mykiss newberrii) marked with 12-mm PIT tags. We redetected 56% (20/36) of brown trout, 34% (68/202) of bull trout, and 33% (20/61) of redband trout after a recovery period of 21 to 46 hours. Models indicate support for length and species and minor support for percent boulder, large woody debris, and percent cobble as parameters important for describing variation in detection efficiency, although 95% confidence intervals for estimates were large. The odds of detecting brown trout (1.5 ± 2.2 [mean ± SE]) are approximately four times as high as bull trout (0.4 ± 1.6) or redband trout (0.3 ± 1.8) and species-specific differences may be related to length. Our reported detection efficiency for brown trout falls within the range of other studies, but is the first reported for bull trout and redband trout. Portable antennas may be a relatively unbiased way of redetecting varying sizes of all three salmonid species.

  4. Egg fatty acid composition from lake trout fed two Lake Michigan prey fish species. (United States)

    Honeyfield, D.C.; Fitzsimons, J.D.; Tillitt, D.E.; Brown, S.B.


    We previously demonstrated that there were significant differences in the egg thiamine content in lake trout Salvelinus namaycush fed two Lake Michigan prey fish (alewife Alosa pseudoharengus and bloater Coregonus hoyi). Lake trout fed alewives produced eggs low in thiamine, but it was unknown whether the consumption of alewives affected other nutritionally important components. In this study we investigated the fatty acid composition of lake trout eggs when females were fed diets that resulted in different egg thiamine concentrations. For 2 years, adult lake trout were fed diets consisting of four combinations of captured alewives and bloaters (100% alewives; 65% alewives, 35% bloaters; 35% alewives, 65% bloaters; and 100% bloaters). The alewife fatty acid profile had higher concentrations of arachidonic acid and total omega-6 fatty acids than the bloater profile. The concentrations of four fatty acids (cis-13, 16-docosadienoic, eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) were higher in bloaters than in alewives. Although six fatty acid components were higher in lake trout eggs in 2001 than in 2000 and eight fatty acids were lower, diet had no effect on any fatty acid concentration measured in lake trout eggs in this study. Based on these results, it appears that egg fatty acid concentrations differ between years but that the egg fatty acid profile does not reflect the alewife-bloater mix in the diet of adults. The essential fatty acid content of lake trout eggs from females fed alewives and bloaters appears to be physiologically regulated and adequate to meet the requirements of developing embryos.

  5. Distribution of heavy metals and radionuclides in sediments, water, and fish in an area of Great Bear Lake contaminated with mine wastes. (United States)

    Moore, J W; Sutherland, D J


    The concentrations of heavy metals and radionuclides in the sediments and water of Great Bear Lake were determined during 1978 near an operating silver mine and an abandoned uranium mine. Additional information on the level of mercury in fish tissues were also collected. The mines, situated on the same site, deposited tailings and other waste material directly into the lake. The concentrations of mercury, lead, manganese, and nickel in the sediments were highest near the tailings deposit and decreased significantly as the distance from the mine increased. Although there were also significant positive correlations between these metals and the organic content of the sediments, water depth and slope of the bottom had no impact on metal distribution. Since the concentrations of arsenic, cobalt, copper, 226radium, 210lead and 230thorium varied inconsistently throughout the study area, the distribution of these substances could not be related to any of the environmental factors that were measured. There were, however, significant negative correlations between the concentrations of 232thorium and 228thorium and distance from the mine and organic content of the sediments. Heavy metal and radionuclide levels in water were generally below detectable limits, reflecting the strong chemical bonding characteristics of the sediments. The low concentrations of mercury in the tissues of lake trout Salvelinus namaycush were probably related to low uptake rates and the ability of this species to move into uncontaminated areas of the lake.

  6. Distribution of heavy metals and radionuclides in sediments, water, and fish in an area of Great Bear Lake contaminated with mine wastes

    Energy Technology Data Exchange (ETDEWEB)

    Moore, J.W.; Sutherland, D.J.


    The concentrations of heavy metals and radionuclides in the sediments and water of Great Bear Lake were determined during 1978 near an operating silver mine and an abandoned uranium mine. Additional information on the level of mercury in fish tissues were also collected. The mines, situated on the same site, deposited tailings and other waste material directly into the lake. The concentrations of mercury, lead, manganese, and nickel in the sediments were highest near the tailings deposit and decreased significantly as the distance from the mine increased. Although there were also significant positive correlations between these metals and the organic content of the sediments, water depth and slope of the bottom had no impact on metal distribution. Since the concentrations of arsenic, cobalt, copper, 226radium, 210lead and 230thorium varied inconsistently throughout the study area, the distribution of these substances could not be related to any of the environmental factors that were measured. There were, however, significant negative correlations between the concentrations of 232thorium and 228thorium and distance from the mine and organic content of the sediments. Heavy metal and radionuclide levels in water were generally below detectable limits, reflecting the strong chemical bonding characteristics of the sediments. The low concentrations of mercury in the tissues of lake trout Salvelinus namaycush were probably related to low uptake rates and the ability of this species to move into uncontaminated areas of the lake.

  7. Visual sensitivity of deepwater fishes in Lake Superior.

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    Kelly A Harrington

    Full Text Available The predator-prey interactions in the offshore food web of Lake Superior have been well documented, but the sensory systems mediating these interactions remain unknown. The deepwater sculpin, (Myoxocephalus thompsoni, siscowet (Salvelinus namaycush siscowet, and kiyi (Coregonus kiyi inhabit low light level environments. To investigate the potential role of vision in predator-prey interactions, electroretinography was used to determine visual sensitivity for each species. Spectral sensitivity curves revealed peak sensitivity at 525 nm for each species which closely corresponds to the prevalent downwelling light spectrum at depth. To determine if sufficient light was available to mediate predator-prey interactions, visual sensitivity was correlated with the intensity of downwelling light in Lake Superior to construct visual depth profiles for each species. Sufficient daytime irradiance exists for visual interactions to approximately 325 m for siscowet and kiyi and 355 m for the deepwater sculpin during summer months. Under full moon conditions, sufficient irradiance exists to elicit ERG response to light available at approximately 30 m for the siscowet and kiyi and 45 m for the deepwater sculpin. Visual interactions are therefore possible at the depths and times when these organisms overlap in the water column indicating that vision may play a far greater role at depth in deep freshwater lakes than had been previously documented.

  8. Predictive models in hazard assessment of Great Lakes contaminants for fish (United States)

    Passino, Dora R. May


    A hazard assessment scheme was developed and applied to predict potential harm to aquatic biota of nearly 500 organic compounds detected by gas chromatography/mass spectrometry (GC/MS) in Great Lakes fish. The frequency of occurrence and estimated concentrations of compounds found in lake trout (Salvelinus namaycush) and walleyes (Stizostedion vitreum vitreum) were compared with available manufacturing and discharge information. Bioconcentration potential of the compounds was estimated from available data or from calculations of quantitative structure-activity relationships (QSAR). Investigators at the National Fisheries Research Center-Great Lakes also measured the acute toxicity (48-h EC50's) of 35 representative compounds to Daphnia pulex and compared the results with acute toxicity values generated by QSAR. The QSAR-derived toxicities for several chemicals underestimated the actual acute toxicity by one or more orders of magnitude. A multiple regression of log EC50 on log water solubility and molecular volume proved to be a useful predictive model. Additional models providing insight into toxicity incorporate solvatochromic parameters that measure dipolarity/polarizability, hydrogen bond acceptor basicity, and hydrogen bond donor acidity of the solute (toxicant).

  9. Thermal onset of cellular and endocrine stress responses correspond to ecological limits in brook trout, an iconic cold-water fish (United States)

    Chadwick, Joseph G; Nislow, Kieth H; McCormick, Stephen


    Climate change is predicted to change the distribution and abundance of species, yet underlying physiological mechanisms are complex and methods for detecting populations at risk from rising temperature are poorly developed. There is increasing interest in using physiological mediators of the stress response as indicators of individual and population-level response to environmental stressors. Here, we use laboratory experiments to show that the temperature thresholds in brook trout (Salvelinus fontinalis) for increased gill heat shock protein-70 (20.7°C) and plasma glucose (21.2°C) are similar to their proposed thermal ecological limit of 21.0°C. Field assays demonstrated increased plasma glucose, cortisol and heat shock protein-70 concentrations at field sites where mean daily temperature exceeded 21.0°C. Furthermore, population densities of brook trout were lowest at field sites where temperatures were warm enough to induce a stress response, and a co-occurring species with a higher thermal tolerance showed no evidence of physiological stress at a warm site. The congruence of stress responses and proposed thermal limits supports the use of these thresholds in models of changes in trout distribution under climate change scenarios and suggests that the induction of the stress response by elevated temperature may play a key role in driving the distribution of species.

  10. A targeted/non-targeted screening method for perfluoroalkyl carboxylic acids and sulfonates in whole fish using quadrupole time-of-flight mass spectrometry and MS(e). (United States)

    Crimmins, Bernard S; Xia, Xiaoyan; Hopke, Philip K; Holsen, Thomas M


    A new method for measuring perfluoroalkyl contaminants (PFCs) in biological matrices has been developed. An ultra-high pressure liquid chromatograph equipped with a quadrupole time-of-flight mass spectrometer (UPLC-QToF) was optimized using a continuous precursor/product ion monitoring mode. Unlike traditional targeted studies that isolate precursor/product ion pairs, the current method alternates between two ionization energy channels to continuously capture standard electrospray ionization (low energy) and collision induced dissociation (high energy) spectra. The result is the indiscriminant acquisition of paired low and high energy spectra for all constituents eluting from the chromatographic system. This technique was evaluated for the routine analysis of perfluoroalkyl species. Using this technique, linear perfluoroalkyl carboxylic acids (C4 to C14) and perfluoroalkyl sulfonates (C4, C6, C8 and C10) exhibited a linear range spanning over three orders of magnitude and were detectable at levels less than 1 pg on column with a root mean squared signal to noise ratio of 5 to 20. Lake trout (Salvelinus namaycush) and National Institutes of Standards and Technology Standard Reference Material 1946 were used to evaluate matrix effects and the accuracy of this method when applied to a whole fish extract. The current method was also evaluated as a diagnostic tool to identify unknown PFCs using experimental fragmentation patterns, mass defect filtering and Kendrick plots.

  11. Evaluation of the Life History of Native Salmonids in the Malheur River Basin; Cooperative Bull Trout/Redband Trout Research Project, 2002-2003 Annual Report.

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    Miller, Alan; Soupir, Jim (US Forest Service, Prairie City Ranger District, Prairie City, OR); Schwabe, Lawrence (Burns Paiute Tribe, Department of Fish and Wildlife, Burns, OR)


    The Malheur River is a 306-kilometer tributary to the Snake River, which drains 12,950 square kilometers. The Malheur River originates in the Blue Mountains and flows into the Snake River near Ontario, Oregon. The climate of the basin is characterized by hot dry summers, occasionally exceeding 38 C, and cold winters that may drop below -29 C. Average annual precipitation is 30 centimeters in the lower reaches. Wooded areas consist primarily of mixed fir and pine forest in the higher elevations. Sagebrush and grass communities dominate the flora in the lower elevations. Efforts to document salmonid life histories, water quality, and habitat conditions have continued in fiscal year 2002. Bull trout Salvelinus confluentus are considered to be cold water species and are temperature-dependant. Due to the interest of bull trout from various state and Federal agencies, a workgroup was formed to develop project objectives related to bull trout. Table 1 lists individuals that participated in the 2002 work group. This report will reflect work completed during the Bonneville Power Administration contract period starting April 1, 2002, and ending March 31, 2003. All tasks were conducted within this timeframe, and a more detailed timeframe may be referred to in each individual report.

  12. Increasing thiamine concentrations in lake trout eggs from Lakes Huron and Michigan coincide with low alewife abundance (United States)

    Riley, Stephen C.; Rinchard, Jacques; Honeyfield, Dale C.; Evans, Allison N.; Begnoche, Linda


    Lake trout Salvelinus namaycush in the Laurentian Great Lakes suffer from thiamine deficiency as a result of adult lake trout consuming prey containing thiaminase, a thiamine-degrading enzyme. Sufficiently low egg thiamine concentrations result in direct mortality of or sublethal effects on newly hatched lake trout fry. To determine the prevalence and severity of low thiamine in lake trout eggs, we monitored thiamine concentrations in lake trout eggs from 15 sites in Lakes Huron and Michigan from 2001 to 2009. Lake trout egg thiamine concentrations at most sites in both lakes were initially low and increased over time at 11 of 15 sites, and the proportion of females with egg thiamine concentrations lower than the recommended management objective of 4 nmol/g decreased over time at eight sites. Egg thiamine concentrations at five of six sites in Lakes Huron and Michigan were significantly inversely related to site-specific estimates of mean abundance of alewives Alosa pseudoharengus, and successful natural reproduction of lake trout has been observed in Lake Huron since the alewife population crashed. These results support the hypothesis that low egg thiamine in Great Lakes lake trout is associated with increased alewife abundance and that low alewife abundance may currently be a prerequisite for successful reproduction by lake trout in the Great Lakes.

  13. Phylogenetic and ecological characteristics associated with thiaminase activity in Laurentian Great Lakes fishes (United States)

    Riley, S.C.; Evans, A.N.


    Thiamine deficiency complex (TDC) causes mortality and sublethal effects in Great Lakes salmonines and results from low concentrations of egg thiamine that are thought to be caused by thiaminolytic enzymes (i.e., thiaminase) present in the diet. This complex has the potential to undermine efforts to restore lake trout Salvelinus namaycush and severely restrict salmonid production in the Great Lakes. Although thiaminase has been found in a variety of Great Lakes fishes, the ultimate source of thiaminase in Great Lakes fishes is currently unknown. We used logistic regression analysis to investigate relationships between thiaminase activity and phylogenetic or ecological characteristics of 39 Great Lakes fish species. The taxonomically more ancestral species were more likely to show thiaminase activity than the more derived species. Species that feed at lower trophic levels and occupy benthic habitats also appeared to be more likely to show thiaminase activity; these variables were correlated with taxonomy, which was the most important predictor of thiaminase activity. Further analyses of the relationship between quantitative measures of thiaminase activity and ecological characteristics of Great Lakes fish species would provide greater insight into potential sources and pathways of thiaminase in Great Lakes food webs. ?? Copyright by the American Fisheries Society 2008.

  14. Dworshak Reservoir Investigations: Trout, Bass and Forage Species, 1987 Annual Report.

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    Statler, David P.


    Dworshak Dam and Reservoir is a Corps of Engineers facility located on the North Fork Clearwater River 3.2 km upstream from the Mainstem Clearwater confluence. Since initial filling in 1971, conversion of 87 km of river habitat to a 6644 hectare impoundment has had a profound influence on resident fisheries. The Nez Perce Tribe and the Idaho Department of Fish and Game (IDFG) entered into separate intergovernmental agreements with the Bonneville Power Administration in a cooperative effort to study these impacts. The kokanee Oncorhynchus nerka assessment is included in the IDFG agreement, and is not addressed in this report. This project pertains primarily to rainbow trout Salmo gairdneri, smallmouth bass (Micropterus dolomieui), and forage species. For the period November 1987 through February 1988, an estimated 4339 angler-hours were expended to catch 430 rainbow trout. An estimated 20 bull trout Salvelinus confluentus, 4 smallmouth bass, and 4 suckers Catostomus spp. were also caught. Catch rates were generally poor through the period, at .091 fish per hour for all species combined (excluding kokanee). Shasta strain hatchery rainbow trout were dominant in the creel, comprising 53.9 percent of the catch, although this strain was last planted in the reservoir in June 1986. Bank anglers caught a higher percentage (93.5 percent) of the total catch of Shasta strain rainbows than Kamloops strain rainbows (33.3 percent). 11 refs., 4 figs., 6 tabs.

  15. Ecology of the Lake Huron fish community, 1970-1999 (United States)

    Dobiesz, Norine E.; McLeish, David A.; Eshenroder, Randy L.; Bence, James R.; Mohr, Lloyd C.; Ebener, Mark P.; Nalepa, Thomas F.; Woldt, Aaron P.; Johnson, James E.; Argyle, Ray L.; Makarewicz, Joseph C.


    We review the status of the Lake Huron fish community between 1970 and 1999 and explore the effects of key stressors. Offshore waters changed little in terms of nutrient enrichment, while phosphorus levels declined in inner Saginaw Bay. Introduced mussels (Dreissena spp.) proliferated and may have caused a decline in Diporeia spp. This introduction could have caused a decline in lake whitefish (Coregonus clupeaformis) growth and condition, with serious repercussions for commercial fisheries. Bythotrephes, an exotic predatory cladoceran, and other new exotics may be influencing the fish community. Sea lampreys (Petromyzon marinus) remained prevalent, but intensive control efforts on the St. Mary's River may reduce their predation on salmonines. Overfishing was less of a problem than in the past, although fishing continued to reduce the amount of lake trout (Salvelinus namaycush) spawning biomass resulting from hatchery-reared fish planted to rehabilitate this species. Massive stocking programs have increased the abundance of top predators, but lake trout were rehabilitated in only one area. Successful lake trout rehabilitation may require lower densities of introduced pelagic prey fish than were seen in the 1990s, along with continued stocking of hatchery-reared lake trout and control of sea lamprey. Such reductions in prey fish could limit Pacific salmon (Oncorhynchus spp.) fisheries.

  16. Low genetic variation in the salmon and trout parasite Loma salmonae (Microsporidia) supports marine transmission and clarifies species boundaries. (United States)

    Brown, Amanda M V; Kent, Michael L; Adamson, Martin L


    Loma salmonae is a microsporidian parasite prevalent in wild and farmed salmon species of the genus Oncorhynchus. This study compared ribosomal RNA (rDNA) and elongation factor-1 alpha (EF-1alpha) gene sequences to look for variation that may provide a basis for distinguishing populations. Specimens were collected from laboratory, captive (sea netpen farm and freshwater hatchery) and wild populations of fish. The host range included rainbow trout O. mykiss, Pacific salmon Oncorhynchus spp. and brook trout Salvelinus fontinalis from British Columbia, Prince Edward Island, Canada, from California, Colorado, Idaho, U.S.A. and from Chile. Both loci suggested that a variant in S. fontinalis (named 'SV') was a separate species. This was supported by the absence of similar variants in the source material (isolated from laboratory-held O. tshawytscha) and high divergence (1.4 to 2.3% in the rDNA and EF-1alpha) from L. salmonae in the type host and locality (0. mykiss in California). L. salmonae from freshwater and anadromous Oncorhynchus spp. were distinguished, providing a basis on which to evaluate possible sources of infection and suggesting geographic boundaries are important. Higher genetic variation occurred among samples of freshwater origin and from a sea netpen farm in Chile, suggesting these environments may present greater population diversity. Invariance in rDNA sequence across 17 samples from anadromous salmon in rivers, lakes, ocean, farms and hatcheries supports the hypothesis that marine transmission occurs and effectively prevents population substructuring caused by freshwater transmission.

  17. Absence of fractionation of mercury isotopes during trophic transfer of methylmercury to freshwater fish in captivity (United States)

    Kwon, Sae Yun; Blum, Joel D.; Carvan, Michael J.; Basu, Niladri; Head, Jessica A.; Madenjian, Charles P.; David, Solomon R.


    We performed two controlled experiments to determine the amount of mass-dependent and mass-independent fractionation (MDF and MIF) of methylmercury (MeHg) during trophic transfer into fish. In experiment 1, juvenile yellow perch (Perca flavescens) were raised in captivity on commercial food pellets and then their diet was either maintained on unamended food pellets (0.1 μg/g MeHg) or was switched to food pellets with 1.0 μg/g or 4.0 μg/g of added MeHg, for a period of 2 months. The difference in δ202Hg (MDF) and Δ199Hg (MIF) between fish tissues and food pellets with added MeHg was within the analytical uncertainty (δ202Hg, 0.07 ‰; Δ199Hg, 0.06 ‰), indicating no isotope fractionation. In experiment 2, lake trout (Salvelinus namaycush) were raised in captivity on food pellets and then shifted to a diet of bloater (Coregonus hoyi) for 6 months. The δ202Hg and Δ199Hg of the lake trout equaled the isotopic composition of the bloater after 6 months, reflecting reequilibration of the Hg isotopic composition of the fish to new food sources and a lack of isotope fractionation during trophic transfer. We suggest that the stable Hg isotope ratios in fish can be used to trace environmental sources of Hg in aquatic ecosystems.

  18. Islands in the ice stream: were spawning habitats for native salmonids in the Great Lakes created by paleo-ice streams? (United States)

    Riley, Stephen; Binder, Thomas R.; Tucker, Taaja R.; Menzies, John; Eyles, Nick; Janssen, John; Muir, Andrew M.; Esselman, Peter C.; Wattrus, Nigel J.; Krueger, Charles C.


    Lake trout Salvelinus namaycush, lake whitefish Coregonus clupeaformis and cisco Coregonus artedi are salmonid fishes native to the Laurentian Great Lakes that spawn on rocky substrates in the fall and early winter. After comparing the locations of spawning habitat for these species in the main basin of Lake Huron with surficial substrates and the hypothesized locations of fast-flowing Late Wisconsinan paleo-ice streams, we hypothesize that much of the spawning habitat for these species in Lake Huron is the result of deposition and erosion by paleo-ice streams. This hypothesis may represent a new framework for the identification and protection of spawning habitat for these native species, some of which are currently rare or extirpated in some of the Great Lakes. We further suggest that paleo-ice streams may have been responsible for the creation of native salmonid spawning habitat elsewhere in the Great Lakes and in other glaciated landscapes.

  19. Polyphasic characterization of Aeromonas salmonicida isolates recovered from salmonid and non-salmonid fish (United States)

    Diamanka, A.; Loch, T.P.; Cipriano, R.C.; Faisal, M.


    Michigan's fisheries rely primarily upon the hatchery propagation of salmonid fish for release in public waters. One limitation on the success of these efforts is the presence of bacterial pathogens, including Aeromonas salmonicida, the causative agent of furunculosis. This study was undertaken to determine the prevalence of A. salmonicida in Michigan fish, as well as to determine whether biochemical or gene sequence variability exists among Michigan isolates. A total of 2202 wild, feral and hatchery-propagated fish from Michigan were examined for the presence of A. salmonicida. The examined fish included Chinook salmon, Oncorhynchus tshawytscha (Walbaum), coho salmon, O. kisutcha (Walbaum), steelhead trout, O. mykiss (Walbaum), Atlantic salmon, Salmo salar L., brook trout, Salvelinus fontinalis (Mitchill), and yellow perch, Perca flavescens (Mitchill). Among these, 234 fish yielded a brown pigment-producing bacterium that was presumptively identified as A. salmonicida. Further phenotypic and phylogenetic analyses identified representative isolates as Aeromonas salmonicida subsp. salmonicida and revealed some genetic and biochemical variability. Logistic regression analyses showed that infection prevalence varied according to fish species/strain, year and gender, whereby Chinook salmon and females had the highest infection prevalence. Moreover, this pathogen was found in six fish species from eight sites, demonstrating its widespread nature within Michigan.

  20. Recovery of a fish pathogenic bacterium, Aeromonas salmonicida, from ebonyshell mussels Fusconaia ebena using nondestructive sample collection procedures (United States)

    Starliper, C.E.


    Refugia are increasingly being used to maintain and propagate imperiled freshwater mussels for future population augmentations. Success for this endeavor is dependent on good husbandry, including a holistic program of resource health management. A significant aspect to optimal health is the prevention or control of infectious diseases. Describing and monitoring pathogens and diseases in mussels involves examination of tissues or samples collected from an appropriate number of individuals that satisfies a certain confidence level for expected prevalences of infections. In the present study, ebonyshell mussels Fusconaia ebena were infected with a fish pathogenic bacterium, Aeromonas salmonicida, through their cohabitation with diseased brook trout Salvelinus fontinalis. At a 100% prevalence of infection, the F. ebena were removed from the cohabitation tank to clean tanks that were supplied with pathogen-free water, which initiated their depuration of A. salmonicida. Three samples (nondestructive fluid, mantle, hemolymph) collected using nondestructive procedures were compared with fluids and soft tissue homogenates collected after sacrificing the mussels for recovery of the bacterium during this period of depuration. Nondestructive sample collections, especially ND fluid, provide a comparable alternative to sacrificing mussels to determine pathogen status.

  1. Water quality trends in the Blackwater River watershed, West Virginia (United States)

    Smith, Jessica; Welsh, Stuart; Anderson, James T.; Fortney, Ronald H.


    An understanding of historic and current water quality is needed to manage and improve aquatic communities within the Blackwater River watershed, WV. The Blackwater River, which historically offered an excellent Salvelinus fontinalis (Brook Trout) fishery, has been affected by logging, coal mining, use of off-road vehicles, and land development. Using information-theoretic methods, we examined trends in water quality at 12 sites in the watershed for the 14 years of 1980–1993. Except for Beaver Creek, downward trends in acidity and upward trends in alkalinity, conductivity, and hardness were consistent with decreases in hydrogen ion concentration. Water-quality trends for Beaver Creek were inconsistent with the other sites and reflect ongoing coal-mining influences. Dissolved oxygen trended downward, possibly due to natural conditions, but remained above thresholds that would be detrimental to aquatic life. Water quality changed only slightly within the watershed from 1980–1993, possibly reflecting few changes in development and land uses during this time. These data serve as a baseline for future water-quality studies and may help to inform management planning.

  2. Investigation of thiamine and PCB association with early life stage fry mortality in lake trout from northwestern Lake Michigan in 1996-1998 (United States)

    Honeyfield, Dale C.; Beltman, Dong; Holey, Mark; Edsall, Carol C.


    Lake trout (Salvelinus namaycush) eggs were collected from 72 females near Sturgeon Bay, WI in northwestern Lake Michigan from 1996, 1997, and 1998 to determine the relationships between egg thiamine and polychlorinated biphenyl (PCB) concentrations with egg fertilization and hatch, prevalence of abnormal fry, and fry mortality. Fry mortality consistent with early mortality syndrome (EMS) was observed in eggs from 33% of the females in 1996, 25% in 1997, and 28% in 1998. Among egg lots exhibiting EMS, fry mortality averaged 95% in 1996, 63% in 1997 and 77% in 1998 compared to 2% or less in lots that did not exhibit EMS. Expression of EMS was strongly correlated with egg thiamine concentrations; egg lots with less than approximately 1 nmol/g total thiamine consistently exhibited high rates of EMS, whereas egg batches with greater than 1.5 nmol/g showed little or no incidence of EMS among swim-up fry. Egg thiamine concentration was not related to fertilization rate, egg hatch, or the prevalence of abnormal fry. There was no relationship between egg concentrations of PCBs or tetrachlorinated dibenzo-p-dioxin (TCDD) equivalents (from PCBs, dioxins, and furans) and any of the egg or fry viability measurements, including EMS. We concluded that fry mortality observed in Lake Michigan lake trout in 1996-1998 was not caused by the toxicity of PCBs, dioxins, and furans, but is due to low egg thiamine concentrations.

  3. Assessment of the Fishery Improvement Opportunities on the Pend Oreille River, 1988 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Barber, Michael R.; Willms, Roger A.; Scholz, Allan T.


    The purpose of this study is to assess the fishery improvement opportunities on the Box Canyon portion of the Pend Oreille River. This report contains the findings of the first year of the study. Chinook salmon (Oncorhynchus tshawytscha (Walbaum)) and steelhead (Oncorhynchus mykiss (Richardson)) were present in the Pend Oreille River prior to the construction of Grand Coulee Dam. The river also contained native cutthroat trout (Oncorhynchus clarki (Richardson)), bull trout (Salvelinus confluentus (Walbaum)) and mountain whitefish (Prosopium williamsoni (Girard)). Rainbow trout were planted in the river and some grew to lengths in excess of 30 inches. With the construction of Box Canyon Dam, in 1955, the most productive section of the river was inundated. Following the construction of the dam the trout fishery declined and the populations of spiny ray fish and rough fish increased. The objectives of the first year of the study were to determine the relative abundance of each species in the river and sloughs; the population levels in fish in the river and four selected tributaries; fish growth rates; the feeding habits and abundance of preferred prey; the migration patterns; and the total fishing pressure, catch per unit effort, and total harvest by conducting a year-round creel survey. 132 refs.

  4. Reevaluation of lake trout and lake whitefish bioenergetics models (United States)

    Madenjian, Charles P.; Pothoven, Steve A.; Kao, Yu-Chun


    Using a corrected algorithm for balancing the energy budget, we reevaluated the Wisconsin bioenergetics model for lake trout (Salvelinus namaycush) in the laboratory and for lake whitefish (Coregonus clupeaformis) in the laboratory and in the field. For lake trout, results showed that the bioenergetics model slightly overestimated food consumption by the lake trout when they were fed low and intermediate rations, whereas the model predicted food consumption by lake trout fed ad libitum without any detectable bias. The slight bias in model predictions for lake trout on restricted rations may have been an artifact of the feeding schedule for these fish, and we would therefore recommend application of the Wisconsin lake trout bioenergetics model to lake trout populations in the field without any revisions to the model. Use of the Wisconsin bioenergetics model for coregonids resulted in overestimation of food consumption by lake whitefish both in the laboratory and in the field by between 20 and 30%, on average. This overestimation of food consumption was most likely due to overestimation of respiration rate. We therefore adjusted the respiration component of the bioenergetics model to obtain a good fit to the observed consumption in our laboratory tanks. The adjusted model predicted the consumption in the laboratory and the field without any detectable bias. Until a detailed lake whitefish respiration study can be conducted, we recommend application of our adjusted version of the Wisconsin generalized coregonid bioenergetics model to lake whitefish populations in the field.

  5. Effects of activity and energy budget balancing algorithm on laboratory performance of a fish bioenergetics model (United States)

    Madenjian, Charles P.; David, Solomon R.; Pothoven, Steven A.


    We evaluated the performance of the Wisconsin bioenergetics model for lake trout Salvelinus namaycush that were fed ad libitum in laboratory tanks under regimes of low activity and high activity. In addition, we compared model performance under two different model algorithms: (1) balancing the lake trout energy budget on day t based on lake trout energy density on day t and (2) balancing the lake trout energy budget on day t based on lake trout energy density on day t + 1. Results indicated that the model significantly underestimated consumption for both inactive and active lake trout when algorithm 1 was used and that the degree of underestimation was similar for the two activity levels. In contrast, model performance substantially improved when using algorithm 2, as no detectable bias was found in model predictions of consumption for inactive fish and only a slight degree of overestimation was detected for active fish. The energy budget was accurately balanced by using algorithm 2 but not by using algorithm 1. Based on the results of this study, we recommend the use of algorithm 2 to estimate food consumption by fish in the field. Our study results highlight the importance of accurately accounting for changes in fish energy density when balancing the energy budget; furthermore, these results have implications for the science of evaluating fish bioenergetics model performance and for more accurate estimation of food consumption by fish in the field when fish energy density undergoes relatively rapid changes.

  6. A New Fluorinated Surfactant Contaminant in Biota: Perfluorobutane Sulfonamide in Several Fish Species. (United States)

    Chu, Shaogang; Letcher, Robert J; McGoldrick, Daryl J; Backus, Sean M


    Environmental contamination and regulation of longer-chain perfluoroalkyl substances (PFASs) such as perfluorooctanesulfonate (PFOS) has given rise to the increased use of shorter-chain PFASs as alternatives in new products, although confirmation of their presence in the environment remains limited. In this study, the PFAS alternative, perfluoro-1-butane-sulfonamide (FBSA), was identified for the first time in biota in homogenate samples of fish by liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-ToF-MS) and quantified by ultra high performance liquid chromatography-triple quadrupole mass spectrometry (UHPLC-QQQ-MS/MS). In one flounder (Platichthys flesus) muscle sample from the Western Scheldt, The Netherlands, FBSA concentration was at 80.12 ng/g wet weight (w.w.) and was exceeded only by PFOS. FBSA was also detected in 32 out of 33 samples of freshwater fish collected (2009-2010) from water bodies across Canada. In lake trout (Salvelinus namaycush) from northern Canada (e.g., Lake Kusawa (Yukon Territory), Great Bear Lake (Northwest Territories and in the Arctic), and Lake Athabasca (northern Alberta)), the concentrations of FBSA ranged from below method detection limit (supermarket in Ottawa (ON, Canada), FBSA concentrations were the lowest of all fish and ranged from chain perfluoroalkyl-based products.

  7. Parasites as biological tags of marine, freshwater and anadromous fishes in North America from the Tropics to the Arctic. (United States)

    Marcogliese, David J; Jacobson, Kym C


    Parasites have been considered as natural biological tags of marine fish populations in North America for almost 75 years. In the Northwest Atlantic, the most studied species include Atlantic cod (Gadus morhua), Atlantic herring (Clupea harengus) and the redfishes (Sebastes spp.). In the North Pacific, research has centred primarily on salmonids (Oncorhynchus spp.). However, parasites have been applied as tags for numerous other pelagic and demersal species on both the Atlantic and Pacific coasts. Relatively few studies have been undertaken in the Arctic, and these were designed to discriminate anadromous and resident salmonids (Salvelinus spp.). Although rarely applied in fresh waters, parasites have been used to delineate certain fish stocks within the Great Lakes-St Lawrence River basin. Anisakid nematodes and the copepod Sphyrion lumpi frequently prove useful indicators in the Northwest Atlantic, while myxozoan parasites prove very effective on the coast and open seas of the Pacific Ocean. Relative differences in the ability of parasites to discriminate between fish stocks on the Pacific and Atlantic coasts may be due to oceanographic and bathymetric differences between regions. Molecular techniques used to differentiate populations and species of parasites show promise in future applications in the field.

  8. The physiological stress response and oxidative stress biomarkers in rainbow trout and brook trout from selenium-impacted streams in a coal mining region

    Energy Technology Data Exchange (ETDEWEB)

    Miller, L.L.; Rasmussen, J.B.; Palace, V.P.; Hontela, A. [University of Lethbridge, Lethbridge, AB (Canada). Dept. of Biological Science


    Selenium (Se) is an essential element that can be toxic at concentrations slightly greater than those required for homeostasis. The main chronic toxic effects of Se in fish are teratogenic deformities, but Se can also activate the physiological stress response and redox cycle with reduced glutathione causing oxidative damage. Rainbow trout, Oncorhynchus mykiss, appear to be more sensitive to Se than brook trout, Salvelinus fontinalis. The objective of this study was to compare the physiological stress response (plasma cortisol, glucose, triiodothyronine, thyroxine, gill Na+/K+ ATPase, cortisol secretory capacity, K and liver somatic index) and oxidative stress biomarkers (liver GSH, GPx, lipid peroxidation, vitamin A and vitamin E) in rainbow trout (RNTR) and brook trout (BKTR) collected from reference and Se-exposed streams. The physiological stress response was not impaired (cortisol secretory capacity unchanged); although there were species differences in plasma cortisol and plasma glucose levels. Liver GSH, GPx and vitamin levels were higher in RNTR than BKTR, but lipid peroxidation levels were not different. The elevated GSH reserves may make RNTR more sensitive to Se-induced lipid peroxidation, but this may be offset by the RNTR's higher antioxidant (GPx and vitamin) levels. Species-specific biochemical differences may mediate differences in Se sensitivity and be used in aquatic Se risk assessments.

  9. Monitor and Protect Wigwam River Bull Trout for Koocanusa Reservoir : Summary of the Skookumchuck Creek Bull Trout Enumeration Project Final Report 2000-2002.

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Jeremy; Baxter, James S.


    This report summarizes the third and final year of a bull trout (Salvelinus confluentus) enumeration project on Skookumchuck Creek in southeastern British Columbia. The fence and traps were operated from September 6th to October 11th 2002 in order to enumerate post-spawning bull trout. During the study period a total of 309 bull trout were captured at the fence. In total, 16 fish of undetermined sex, 114 males and 179 females were processed at the fence. Length and weight data, as well as recapture information, were collected for these fish. An additional 41 bull trout were enumerated upstream of the fence by snorkeling prior to fence removal. Coupled with the fence count, the total bull trout enumerated during the project was 350 individuals. Several fish that were tagged in the lower Bull River were recaptured in 2002, as were repeat and alternate year spawners previously enumerated in past years at the fence. A total of 149 bull trout redds were enumerated on the ground in 2002, of which 143 were in the 3.0 km index section (river km 27.5-30.5) that has been surveyed over the past six years. The results of the three year project are summarized, and population characteristics are discussed.

  10. Agonistic behavior among three stocked trout species in a novel reservoir fish community (United States)

    Budy, Phaedra; Hafen, Konrad


    The popularity of reservoirs to support sport fisheries has led to the stocking of species that did not co-evolve, creating novel reservoir fish communities. In Utah, the Bear Lake strain of Bonneville Cutthroat Trout Oncorhynchus clarkii utah and tiger trout (female Brown Trout Salmo trutta × male Brook Trout Salvelinus fontinalis) are being more frequently added to a traditional stocking regimen consisting primarily of Rainbow TroutO. mykiss. Interactions between these three predatory species are not well understood, and studies evaluating community interactions have raised concern for an overall decrease of trout condition. To evaluate the potential for negative interactions among these species, we tested aggression in laboratory aquaria using three-species and pairwise combinations at three densities. Treatments were replicated before and after feeding. During the three-species trials Rainbow Trout initiated 24.8 times more aggressive interactions than Cutthroat Trout and 10.2 times more aggressive interactions than tiger trout, and tiger trout exhibited slightly (1.9 times) more aggressive initiations than Cutthroat Trout. There was no significant difference in behavior before versus after feeding for any species, and no indication of increased aggression at higher densities. Although Rainbow Trout in aquaria may benefit from their bold, aggressive behavior, given observations of decreased relative survival in the field, these benefits may be outweighed in reservoirs, possibly through unnecessary energy expenditure and exposure to predators.

  11. Seasonal patterns in growth, blood consumption, and effects on hosts by parasitic-phase sea lampreys in the Great Lakes: an individual-based model approach (United States)

    Madenjian, Charles P.; Cochran, Philip A.; Bergstedt, Roger A.


    An individual-based model (IBM) was developed for sea lamprey (Petromyzon marinus) populations in the Laurentian Great Lakes. The IBM was then calibrated to observed growth, by season, for sea lampreys in northern Lake Huron under two different water temperature regimes: a regime experienced by Seneca-strain lake trout (Salvelinus namaycush) and a regime experienced by Marquettestrain lake trout. Modeling results indicated that seasonal blood consumption under the Seneca regime was very similar to that under the Marquette regime. Simulated mortality of lake trout directly due to blood removal by sea lampreys occurred at nearly twice the rate during August and September under the Marquette regime than under the Seneca regime. However, cumulative sea lamprey-induced mortality on lake trout over the entire duration of the sea lamprey's parasitic phase was only 7% higher for the Marquette regime compared with the Seneca regime. Thus, these modeling results indicated that the strain composition of the host (lake trout) population was not important in determining total number of lake trout deaths or total blood consumption attributable to the sea lamprey population, given the sea lamprey growth pattern. Regardless of water temperature regime, both blood consumption rate by sea lampreys and rate of sea lamprey-induced mortality on lake trout peaked in late October. Elevated blood consumption in late October appeared to be unrelated to changes in water temperature. The IBM approach should prove useful in optimizing control of sea lampreys in the Laurentian Great Lakes.

  12. Diet and prey selection by Lake Superior lake trout during springs 1986-2001 (United States)

    Ray, B.A.; Hrabik, T.R.; Ebener, M.P.; Gorman, O.T.; Schreiner, D.R.; Schram, S.T.; Sitar, S.P.; Mattes, W.P.; Bronte, C.R.


    We describe the diet and prey selectivity of lean (Salvelinus namaycush namaycush) and siscowet lake trout (S. n. siscowet) collected during spring (April–June) from Lake Superior during 1986–2001. We estimated prey selectivity by comparing prey numerical abundance estimates from spring bottom trawl surveys and lake trout diet information in similar areas from spring gill net surveys conducted annually in Lake Superior. Rainbow smelt (Osmerus mordax) was the most common prey and was positively selected by both lean and siscowet lake trout throughout the study. Selection by lean lake trout for coregonine (Coregonus spp.) prey increased after 1991 and corresponded with a slight decrease in selection for rainbow smelt. Siscowet positively selected for rainbow smelt after 1998, a change that was coincident with the decrease in selection for this prey item by lean lake trout. However, diet overlap between lean and siscowet lake trout was not strong and did not change significantly over the study period. Rainbow smelt remains an important prey species for lake trout in Lake Superior despite declines in abundance.

  13. Predicting recolonization patterns and interactions between potamodromous and anadromous salmonids in response to dam removal in the Elwha River, Washington State, USA (United States)

    Brenkman, S.J.; Pess, G.R.; Torgersen, C.E.; Kloehn, K.K.; Duda, J.J.; Corbett, S.C.


    The restoration of salmonids in the Elwha River following dam removal will cause interactions between anadromous and potamodromous forms as recolonization occurs in upstream and downstream directions. Anadromous salmonids are expected to recolonize historic habitats, and rainbow trout (Oncorhynchus mykiss) and bull trout (Salvelinus confluentus) isolated above the dams for 90 years are expected to reestablish anadromy. We summarized the distribution and abundance of potamodromous salmonids, determined locations of spawning areas, and mapped natural barriers to fish migration at the watershed scale based on data collected from 1993 to 2006. Rainbow trout were far more abundant than bull trout throughout the watershed and both species were distributed up to river km 71. Spawning locations for bull trout and rainbow trout occurred in areas where we anticipate returning anadromous fish to spawn. Nonnative brook trout were confined to areas between and below the dams, and seasonal velocity barriers are expected to prevent their upstream movements. We hypothesize that the extent of interaction between potamodromous and anadromous salmonids will vary spatially due to natural barriers that will limit upstream-directed recolonization for some species of salmonids. Consequently, most competitive interactions will occur in the main stem and floodplain downstream of river km 25 and in larger tributaries. Understanding future responses of Pacific salmonids after dam removal in the Elwha River depends upon an understanding of existing conditions of the salmonid community upstream of the dams prior to dam removal.

  14. Lake trout rehabilitation in Lake Erie: a case history (United States)

    Cornelius, Floyd C.; Muth, Kenneth M.; Kenyon, Roger


    Native lake trout (Salvelinus namaycush) once thrived in the deep waters of eastern Lake Erie. The impact of nearly 70 years of unregulated exploitation and over 100 years of progressively severe cultural eutrophication resulted in the elimination of lake trout stocks by 1950. Early attempts to restore lake trout by stocking were unsuccessful in establishing a self-sustaining population. In the early 1980s, New York's Department of Environmental Conservation, Pennsylvania's Fish and Boat Commission, and the U.S. Fish and Wildlife Service entered into a cooperative program to rehabilitate lake trout in the eastern basin of Lake Erie. After 11 years of stocking selected strains of lake trout in U.S. waters, followed by effective sea lamprey control, lake trout appear to be successfully recolonizing their native habitat. Adult stocks have built up significantly and are expanding their range in the lake. Preliminary investigations suggest that lake trout reproductive habitat is still adequate for natural reproduction, but natural recruitment has not been documented. Future assessments will be directed toward evaluation of spawning success and tracking age-class cohorts as they move through the fishery.

  15. Morphological variation of siscowet lake trout in Lake Superior (United States)

    Bronte, C.R.; Moore, S.A.


    Historically, Lake Superior has contained many morphologically distinct forms of the lake trout Salvelinus namaycush that have occupied specific depths and locations and spawned at specific times of the year. Today, as was probably the case historically, the siscowet morphotype is the most abundant. Recent interest in harvesting siscowets to extract oil containing omega-3 fatty acids will require additional knowledge of the biology and stock structure of these lightly exploited populations. The objective of this study was to determine whether shape differences exist among siscowet populations across Lake Superior and whether these shape differences can be used to infer stock structure. Morphometric analysis (truss protocol) was used to differentiate among siscowets sampled from 23 locations in Lake Superior. We analyzed 31 distance measurements among 14 anatomical landmarks taken from digital images of fish recorded in the field. Cluster analysis of size-corrected data separated fish into three geographic groups: The Isle Royale, eastern (Michigan), and western regions (Michigan). Finer scales of stock structure were also suggested. Discriminant function analysis demonstrated that head measurements contributed to most of the observed variation. Cross-validation classification rates indicated that 67–71% of individual fish were correctly classified to their region of capture. This is the first study to present shape differences associated with location within a lake trout morphotype in Lake Superior.

  16. Delineation of sympatric morphotypes of lake trout in Lake Superior (United States)

    Moore, Seth A.; Bronte, Charles R.


    Three morphotypes of lake trout Salvelinus namaycush are recognized in Lake Superior: lean, siscowet, and humper. Absolute morphotype assignment can be difficult. We used a size-free, whole-body morphometric analysis (truss protocol) to determine whether differences in body shape existed among lake trout morphotypes. Our results showed discrimination where traditional morphometric characters and meristic measurements failed to detect differences. Principal components analysis revealed some separation of all three morphotypes based on head and caudal peduncle shape, but it also indicated considerable overlap in score values. Humper lake trout have smaller caudal peduncle widths to head length and depth characters than do lean or siscowet lake trout. Lean lake trout had larger head measures to caudal widths, whereas siscowet had higher caudal peduncle to head measures. Backward stepwise discriminant function analysis retained two head measures, three midbody measures, and four caudal peduncle measures; correct classification rates when using these variables were 83% for leans, 80% for siscowets, and 83% for humpers, which suggests the measures we used for initial classification were consistent. Although clear ecological reasons for these differences are not readily apparent, patterns in misclassification rates may be consistent with evolutionary hypotheses for lake trout within the Laurentian Great Lakes.

  17. [Variability of nucleotide sequences of the mitochondrial DNA cytochrome c gene in dolly varden and taranetz char]. (United States)

    Radchenko, O A; Derenko, M V; Maliarchuk, B A


    Nucleotide sequence of the 307-bp fragment of the mitochondrial DNA cytochrome b gene was determined in representatives of the three species of the Salvelinus genus, specifically, dolly varden char (S. malma), taranetz char (S. taranetzi), and white-spotted char (S. leucomaenis). These results pointed to a high level of mitochondrial DNA (mtDNA) divergence between white-spotted char and dolly varden char, on the one hand, and taranetz char, on the other (the mean d value was 5.45%). However, the divergence between the dolly varden char and taranetz char was only 0.81%, which is comparable with the level of intraspecific divergence in the dolly varden char (d = 0.87%). It was shown that the dolly varden char mitochondrial gene pool contained DNA lineages differing from the main mtDNA pool at least in the taranetz char-specific mitochondrial lineages. One of these dolly varden char mtDNA lineages was characterized by the presence of the restriction endonuclease MspI-D variant of the cytochrome b gene. This lineage was widely distributed in the Chukotka populations but it was not detected in the Yana River (Okhotsk sea) populations. These findings suggest that dolly varden char has a more ancient evolutionary lineage, diverging from the common ancestor earlier than did taranetz char.

  18. Total mercury concentrations in anadromous Northern Dolly Varden from the northwestern Canadian Arctic: a historical baseline study. (United States)

    Tran, L; Reist, J D; Power, M


    Previous research has documented the significance of total mercury (THg) as a northern contaminant in general and of fish in particular. While much research has been devoted to documenting both spatial and temporal changes in THg in consumed fish, little effort has been directed at understanding patterns of THg in Dolly Varden (Salvelinus malma), a prized subsistence species throughout the western North American Arctic. Here we report historical THg concentrations for anadromous Dolly Varden from 10 populations in the Yukon and Northwest Territories sampled across a range of latitudes (67-69°N) and longitudes (136-141°W) between the years 1988-91. Unadjusted mean THg concentrations ranged from 15 to 254 ng/g wet weight. Length-adjusted THg concentrations were significantly different among sites, but were not related to latitude or longitude. Within and among populations, THg was significantly related to fork-length, age, δ(15)N, and δ(13)C, with the variation in THg found among populations being best explained by size. The data serve as an important baseline against which future changes in THg levels in this important subsistence fishery may be compared to determine the significance of any observed trends.

  19. Evolutionary relationships among sympatric life history forms of Dolly Varden inhabiting the landlocked Kronotsky Lake, Kamchatka, and a neighboring anadromous population (United States)

    Ostberg, C.O.; Pavlov, S.D.; Hauser, L.


    We investigated the evolutionary relationships among five sympatric morphs of Dolly Varden Salvelinus malma (white, Schmidti, longhead, river, and dwarf) inhabiting landlocked Kronotsky Lake on the Kamchatka Peninsula, Russia, and an anadromous population below the barrier waterfall on the outflowing Kronotsky River. Morphological analyses indicated phenotypic differentiation corresponding to preferred habitat, the longhead (a limnetic piscivorous morph) having a fusiform body, long jaw, and short fins and the Schmidti (a benthic morph) having a robust body, small jaw, and long fins. Analysis of molecular variance among the Kronotsky Lake morphs indicated that contemporary gene flow is restricted both among morphs within locations and among locations within morphs. Gene flow from Kronotsky Lake into the anadromous population also appears to be restricted. Our findings indicate that there are two divergent evolutionary lineages, one consisting of the white, Schmidti, river, and dwarf morphs and the other of the longhead morph and the anadromous population, which suggests that Kronotsky Lake was subject to separate waves of immigration. The Kronotsky Lake Dolly Varden morphs may represent an example of ecological speciation in progress, and we present a working hypothesis for the diversification of morphs within Kronotsky Lake.

  20. Is isolation by adaptation driving genetic divergence among proximate Dolly Varden char populations? (United States)

    Bond, Morgan H; Crane, Penelope A; Larson, Wesley A; Quinn, Tom P


    Numerous studies of population genetics in salmonids and other anadromous fishes have revealed that population structure is generally organized into geographic hierarchies (isolation by distance), but significant structure can exist in proximate populations due to varying selective pressures (isolation by adaptation). In Chignik Lakes, Alaska, anadromous Dolly Varden char (Salvelinus malma) spawn in nearly all accessible streams throughout the watershed, including those draining directly to an estuary, Chignik Lagoon, into larger rivers, and into lakes. Collections of Dolly Varden fry from 13 streams throughout the system revealed low levels of population structure among streams emptying into freshwater. However, much stronger genetic differentiation was detected between streams emptying into freshwater and streams flowing directly into estuarine environments. This fine-scale reproductive isolation without any physical barriers to migration is likely driven by differences in selection pressures across freshwater and estuarine environments. Estuary tributaries had fewer larger, older juveniles, suggesting an alternative life history of smolting and migration to the marine environment at a much smaller size than occurs in the other populations. Therefore, genetic data were consistent with a scenario where isolation by adaptation occurs between populations of Dolly Varden in the study system, and ecological data suggest that this isolation may partially be a result of a novel Dolly Varden life history of seawater tolerance at a smaller size than previously recognized.

  1. Consequences of seasonal variation in reservoir water level for predatory fishes: linking visual foraging and prey densities (United States)

    Klobucar, Stephen L.; Budy, Phaedra


    In reservoirs, seasonal drawdown can alter the physical environment and may influence predatory fish performance. We investigated the performance of lake trout (Salvelinus namaycush) in a western reservoir by coupling field measurements with visual foraging and bioenergetic models at four distinct states (early summer, mid-summer, late summer, and fall). The models suggested that lake trout prey, juvenile kokanee (Oncorhynchus nerka), are limited seasonally by suitable temperature and dissolved oxygen. Accordingly, prey densities were greatest in late summer when reservoir volume was lowest and fish were concentrated by stratification. Prey encounter rates (up to 68 fish·day−1) and predator consumption are also predicted to be greatest during late summer. However, our models suggested that turbidity negatively correlates with prey detection and consumption across reservoir states. Under the most turbid conditions, lake trout did not meet physiological demands; however, during less turbid periods, predator consumption reached maximum bioenergetic efficiency. Overall, our findings demonstrate that rapid reservoir fluctuations and associated abiotic conditions can influence predator–prey interactions, and our models describe the potential impacts of water level fluctuation on valuable sport fishes.

  2. Aquatic and terrestrial organic matter in the diet of stream consumers: implications for mercury bioaccumulation. (United States)

    Jardine, Timothy D; Kidd, Karen A; Rasmussen, Joseph B


    The relative contribution of aquatic vs. terrestrial organic matter to the diet of consumers in fluvial environments and its effects on bioaccumulation of contaminants such as mercury (Hg) remain poorly understood. We used stable isotopes of carbon and nitrogen in a gradient approach (consumer isotope ratio vs. periphyton isotope ratio) across temperate streams that range in their pH to assess consumer reliance on aquatic (periphyton) vs. terrestrial (riparian vegetation) organic matter, and whether Hg concentrations in fish and their prey were related to these energy sources. Taxa varied in their use of the two sources, with grazing mayflies (Heptageniidae), predatory stoneflies (Perlidae), one species of water strider (Metrobates hesperius), and the fish blacknose dace (Rhinichthys atratulus) showing strong connections to aquatic sources, while Aquarius remigis water striders and brook trout (Salvelinus fontinalis) showed a weak link to in-stream production. The aquatic food source for consumers, periphyton, had higher Hg concentrations in low-pH waters, and pH was a much better predictor of Hg in predatory invertebrates that relied mainly on this food source vs. those that used terrestrial C. These findings suggest that stream biota relying mainly on dietary inputs from the riparian zone will be partially insulated from the effects of water chemistry on Hg availability. This has implications for the development of a whole-system understanding of nutrient and material cycling in streams, the choice of taxa in contaminant monitoring studies, and in understanding the fate of Hg in stream food webs.

  3. Bull Trout Life History, Genetics, Habitat Needs, and Limiting Fact in Central and Northeast Oregon. Annual Report 1999.

    Energy Technology Data Exchange (ETDEWEB)

    Hemmingsen, Alan R.; Gunckel, Stephanie L.; Howell, Philip J.


    This section describes work accomplished in 1999 that continued to address two objectives of this project. These objectives are (1) determine the distribution of juvenile and adult bull trout Salvelinus confluentus and habitats associated with that distribution, and (2) determine fluvial and resident bull trout life history patterns. Completion of these objectives is intended through studies of bull trout in the Grande Ronde, Walla Walla, and John Day basins. These basins were selected because they provide a variety of habitats, from relatively degraded to pristine, and bull trout populations were thought to vary from relatively depressed to robust. In all three basins we used radio telemetry to determine the seasonal movements of bull trout. In the John Day and Walla Walla basins we also used traps to capture migrant bull trout. With these traps, we intended to determine the timing of bull trout movements both upstream and downstream, determine the relative abundance, size and age of migrant fish, and capture bull trout to be implanted with radio transmitters. In the John Day basin, we captured adult and juvenile bull trout from the upper John Day River and its tributaries, Call Creek, Reynolds Creek, and Roberts Creek. In the Walla Walla basin, we captured adult and juvenile bull trout from Mill Creek.

  4. Species replacement by a nonnative salmonid alters ecosystem function by reducing prey subsidies that support riparian spiders. (United States)

    Benjamin, Joseph R; Fausch, Kurt D; Baxter, Colden V


    Replacement of a native species by a nonnative can have strong effects on ecosystem function, such as altering nutrient cycling or disturbance frequency. Replacements may cause shifts in ecosystem function because nonnatives establish at different biomass, or because they differ from native species in traits like foraging behavior. However, no studies have compared effects of wholesale replacement of a native by a nonnative species on subsidies that support consumers in adjacent habitats, nor quantified the magnitude of these effects. We examined whether streams invaded by nonnative brook trout (Salvelinus fontinalis) in two regions of the Rocky Mountains, USA, produced fewer emerging adult aquatic insects compared to paired streams with native cutthroat trout (Oncorhynchus clarkii), and whether riparian spiders that depend on these prey were less abundant along streams with lower total insect emergence. As predicted, emergence density was 36% lower from streams with the nonnative fish. Biomass of brook trout was higher than the cutthroat trout they replaced, but even after accounting for this difference, emergence was 24% lower from brook trout streams. More riparian spiders were counted along streams with greater total emergence across the water surface. Based on these results, we predicted that brook trout replacement would result in 6-20% fewer spiders in the two regions. When brook trout replace cutthroat trout, they reduce cross-habitat resource subsidies and alter ecosystem function in stream-riparian food webs, not only owing to increased biomass but also because traits apparently differ from native cutthroat trout.

  5. Effects of exotic species on Yellowstone's grizzly bears (United States)

    Reinhart, D.P.; Haroldson, Mark A.; Mattson, D.J.; Gunther, Kerry A.


    Humans have affected grizzly bears (Ursus arctos horribilis) by direct mortality, competition for space and resources, and introduction of exotic species. Exotic organisms that have affected grizzly bears in the Greater Yellowstone Area include common dandelion (Taraxacum officinale), nonnative clovers (Trifolium spp.), domesticated livestock, bovine brucellosis (Brucella abortus), lake trout (Salvelinus namaycush), and white pine blister rust (Cronartium ribicola). Some bears consume substantial amounts of dandelion and clover. However, these exotic foods provide little digested energy compared to higher-quality bear foods. Domestic livestock are of greater energetic value, but use of this food by bears often leads to conflicts with humans and subsequent increases in bear mortality. Lake trout, blister rust, and brucellosis diminish grizzly bears foods. Lake trout prey on native cutthroat trout (Oncorhynchus clarkii) in Yellowstone Lake; white pine blister rust has the potential to destroy native whitebark pine (Pinus albicaulis) stands; and management response to bovine brucellosis, a disease found in the Yellowstone bison (Bison bison) and elk (Cervus elaphus), could reduce populations of these 2 species. Exotic species will likely cause more harm than good for Yellowstone grizzly bears. Managers have few options to mitigate or contain the impacts of exotics on Yellowstones grizzly bears. Moreover, their potential negative impacts have only begun to unfold. Exotic species may lead to the loss of substantial highquality grizzly bear foods, including much of the bison, trout, and pine seeds that Yellowstone grizzly bears currently depend upon.

  6. Are brook trout streams in Western Virginia and Shenandoah National Park recovering from acidification?

    Energy Technology Data Exchange (ETDEWEB)

    James R. Webb; Bernard J. Cosby; Frank A. Deviney, Jr.; James N. Galloway; Suzanne W. Maben; Arthur J. Bulger [University of Virginia, Charlottesville, VA (United States). Department of Environmental Sciences


    Streamwater composition data obtained through periodic sampling of streams that support brook trout (Salvelinus fontinalis) in the mountains of western Virginia were examined for evidence of recovery from acidification during the 1988-2001 period. Measurements of sulfate deposition in precipitation indicate that sulfate deposition in the region declined approximately 40% between 1985 and 2000. While no significant regional trends in acid-base constituents were observed for the set (n = 65) of western Virginia study streams, significant regional trends were observed for a subset (n = 14) of streams in Shenandoah National Park (SNP). For the subset of SNP streams, the median increase in acid-neutralizing capacity (ANC) was 0.168 {mu} equiv L{sup -1} year{sup -1} and the median decrease in sulfate concentration was -0.229 {mu}equiv L{sup -1} year{sup -1}. Although these trends are consistent with recovery from acidification, the degree of apparent recovery is small compared to estimates of historic acidification in SNP streams and much less than observed in other, more northern regions in the United States. Correlation between sulfate concentration trends and current sulfate concentrations in streamwater suggests that recovery from stream acidification in the western Virginia region is determined by sulfur retention processes in watershed soils. A transient increase in nitrate concentrations that occurred among some western Virginia streams following forest defoliation by the gypsy moth (Lymantria dispar) complicates interpretation of the observed patterns of change in acid-base status. 28 refs., 6 figs., 1 tab.

  7. Susceptibility of various Japanese freshwater fish species to an isolate of viral haemorrhagic septicaemia virus (VHSV) genotype IVb. (United States)

    Ito, Takafumi; Olesen, Niels Jørgen


    Genotype IVb of viral haemorrhagic septicaemia virus (VHSV) was isolated for the first time in the Great Lakes basin in 2003, where it spread and caused mass mortalities in several wild fish species throughout the basin. In order to prevent further spreading of the disease and to assess risks of new genotypes invading new watersheds, basic microbiological information such as pathogenicity studies are essential. In this study, experimental infections were conducted on 7 indigenous freshwater fish species from Japan by immersion with a VHSV genotype IVb isolate. In Expt 1, cumulative mortalities in bluegill Lepomis macrochirus used as positive controls, Japanese fluvial sculpin Cottus pollux, and iwana Salvelinus leucomaenis pluvius were 50, 80 and 0%, respectively. In Expt 2, cumulative mortalities of 100, 100 and 10% were observed in Japanese fluvial sculpin C. pollux, Japanese rice fish Oryzias latipes and yoshinobori Rhinogobius sp., respectively. No mortality was observed in honmoroko Gnathopogon caerulescens, akaza Liobagrus reini or Japanese striped loach Cobitis biwae. VHSV was detected by RT-PCR from samples of kidney, spleen, and brain from all dead fish, and virus re-isolation by cell culture was successful from all dead fish. We detected the virus in the brain from a few surviving bluegill 50 d post exposure by both cell culture and RT-PCR. These results revealed that VHSV IVb could become a serious threat to wild freshwater fish species in Japan, and that some surviving fish might become healthy carriers of the virus.

  8. Lake trout otolith chronologies as multidecadal indicators of high-latitude freshwater ecosystems (United States)

    Black, B.A.; Von Biela, V.R.; Zimmerman, C.E.; Brown, Randy J.


    High-latitude ecosystems are among the most vulnerable to long-term climate change, yet continuous, multidecadal indicators by which to gauge effects on biology are scarce, especially in freshwater environments. To address this issue, dendrochronology (tree-ring analysis) techniques were applied to growth-increment widths in otoliths from lake trout (Salvelinus namaycush) from the Chandler Lake system, Alaska (68.23°N, 152.70°W). All otoliths were collected in 1987 and exhibited highly synchronous patterns in growth-increment width. Increments were dated, the widths were measured, and age-related growth declines were removed using standard dendrochronology techniques. The detrended time series were averaged to generate an annually resolved chronology, which continuously spanned 1964–1984. The chronology positively and linearly correlated with August air temperature over the 22-year interval (p productivity. Given the broad distribution of lake trout within North America, this study suggests that otolith chronologies could be used to examine responses between freshwater ecosystems and environmental variability across a range of temporal and spatial scales.

  9. Stable isotope evaluation of population- and individual-level diet variability in a large, oligotrophic lake with non-native lake trout (United States)

    Ng, Elizabeth L.; Fredericks, Jim P.; Quist, Michael C.


    Non-native piscivores can alter food web dynamics; therefore, evaluating interspecific relationships is vital for conservation and management of ecosystems with introduced fishes. Priest Lake, Idaho, supports a number of introduced species, including lake troutSalvelinus namaycush, brook trout S. fontinalis and opossum shrimp Mysis diluviana. In this study, we used stable isotopes (δ13C and δ15N) to describe the food web structure of Priest Lake and to test hypotheses about apparent patterns in lake trout growth. We found that isotopic niches of species using pelagic-origin carbon did not overlap with those using more littoral-origin carbon. Species using more littoral-origin carbon, such as brook trout and westslope cutthroat trout Oncorhynchus clarki lewisi, exhibited a high degree of isotopic niche overlap and high intrapopulation variability in resource use. Although we hypothesised that lake trout would experience an ontogenetic diet shift, no such patterns were apparent in isotopic signatures. Lake trout growth rates were not associated with patterns in δ15N, indicating that variation in adult body composition may not be related to adult diet. Understanding trophic relationships at both the individual and species levels provides a more complete understanding of food webs altered by non-native species.

  10. Characterizing the thermal suitability of instream habitat for salmonids: A cautionary example from the Rocky Mountains (United States)

    Al-Chokhachy, Robert K.; Wegner, Seth J.; Isaak, Daniel J.; Kershner, Jeffrey L.


    Understanding a species’ thermal niche is becoming increasingly important for management and conservation within the context of global climate change, yet there have been surprisingly few efforts to compare assessments of a species’ thermal niche across methods. To address this uncertainty, we evaluated the differences in model performance and interpretations of a species’ thermal niche when using different measures of stream temperature and surrogates for stream temperature. Specifically, we used a logistic regression modeling framework with three different indicators of stream thermal conditions (elevation, air temperature, and stream temperature) referenced to a common set of Brook Trout Salvelinus fontinalis distribution data from the Boise River basin, Idaho. We hypothesized that stream temperature predictions that were contemporaneous with fish distribution data would have stronger predictive performance than composite measures of stream temperature or any surrogates for stream temperature. Across the different indicators of thermal conditions, the highest measure of accuracy was found for the model based on stream temperature predictions that were contemporaneous with fish distribution data (percent correctly classified = 71%). We found considerable differences in inferences across models, with up to 43% disagreement in the amount of stream habitat that was predicted to be suitable. The differences in performance between models support the growing efforts in many areas to develop accurate stream temperature models for investigations of species’ thermal niches.

  11. Mercury levels in herring gulls and fish: 42 years of spatio-temporal trends in the Great Lakes. (United States)

    Blukacz-Richards, E Agnes; Visha, Ariola; Graham, Matthew L; McGoldrick, Daryl L; de Solla, Shane R; Moore, David J; Arhonditsis, George B


    Total mercury levels in aquatic birds and fish communities have been monitored across the Canadian Great Lakes by Environment and Climate Change Canada (ECCC) for the past 42 years (1974-2015). These data (22 sites) were used to examine spatio-temporal variability of mercury levels in herring gull (Larus argentatus) eggs, lake trout (Salvelinus namaycush), walleye (Sander vitreus), and rainbow smelt (Osmerus mordax). Trends were quantified with dynamic linear models, which provided time-variant rates of change of mercury concentrations. Lipid content (in both fish and eggs) and length in fish were used as covariates in all models. For the first three decades, mercury levels in gull eggs and fish declined at all stations. In the 2000s, trends for herring gull eggs reversed at two sites in Lake Erie and two sites in Lake Ontario. Similar trend reversals in the 2000s were observed for lake trout in Lake Superior and at a single station in Lake Ontario. Mercury levels in lake trout continued to slowly decline at all of the remaining stations, except for Lake Huron, where the levels remained stable. A post-hoc Bayesian regression analysis suggests strong trophic interactions between herring gulls and rainbow smelt in Lake Superior and Lake Ontario, but also pinpoints the likelihood of a trophic decoupling in Lake Huron and Lake Erie. Continued monitoring of mercury levels in herring gulls and fish is required to consolidate these trophic shifts and further evaluate their broader implications.

  12. Episodic acidification of small streams in the northeastern united states: Effects on fish populations (United States)

    Baker, J.P.; Van Sickle, J.; Gagen, C.J.; DeWalle, David R.; Sharpe, W.E.; Carline, R.F.; Baldigo, Barry P.; Murdoch, Peter S.; Bath, D.W.; Kretser, W.A.; Simonin, H.A.; Wigington, P.J.


    As part of the Episodic Response Project (ERP), we studied the effects of episodic acidification on fish in 13 small streams in the northeastern United States: four streams in the Adirondack region of New York, four streams in the Catskills, New York, and five streams in the northern Appalachian Plateau, Pennsylvania. In situ bioassays with brook trout (Salvelinus fontinalis) and a forage fish species (blacknose dace (Rhinichthys atratulus], mottled sculpin (Cottus bairdi), or slimy sculpin (Cottus cognatus), depending on the region) measured direct toxicity. Movements of individual brook trout, in relation to stream chemistry, were monitored using radiotelemetry. Electrofishing surveys assessed fish community status and the density and biomass of brook trout in each stream. During low flow, all streams except one had chemical conditions considered suitable for the survival and reproduction of most fish species (median pH 6.0-7.2 during low flow; inorganic Al 100-200 ??g/L. We conclude that episodic acidification can have long-term effects on fish communities in small streams.

  13. Accounting for adaptive capacity and uncertainty in assessments of species’ climate-change vulnerability (United States)

    Wade, Alisa A.; Hand, Brian K.; Kovach, Ryan; Luikart, Gordon; Whited, Diane; Muhlfeld, Clint C.


    Climate change vulnerability assessments (CCVAs) are valuable tools for assessing species’ vulnerability to climatic changes, yet failure to include measures of adaptive capacity and to account for sources of uncertainty may limit their effectiveness. Here, we provide a more comprehensive CCVA approach that incorporates all three elements used for assessing species’ climate change vulnerability: exposure, sensitivity, and adaptive capacity. We illustrate our approach using case studies of two threatened salmonids with different life histories – anadromous steelhead trout (Oncorhynchus mykiss) and non-anadromous bull trout (Salvelinus confluentus) – within the Columbia River Basin, USA. We identified general patterns of high vulnerability in low-elevation and southernmost habitats for both species. However, vulnerability rankings varied widely depending on the factors (climate, habitat, demographic, and genetic) included in the CCVA and often differed for the two species at locations where they were sympatric. Our findings illustrate that CCVA results are highly sensitive to data inputs and that spatial differences can complicate multi-species conservation. Our results highlight how CCVAs should be considered within a broader conceptual and computational framework for refining hypotheses, guiding research, and comparing plausible scenarios of species’ vulnerability for ongoing and projected climate change.

  14. Evidence of Lake Trout reproduction at Lake Michigan's mid-lake reef complex (United States)

    Janssen, J.; Jude, D.J.; Edsall, T.A.; Paddock, R.W.; Wattrus, N.; Toneys, M.; McKee, P.


    The Mid-Lake Reef Complex (MLRC), a large area of deep (> 40 m) reefs, was a major site where indigenous lake trout (Salvelinus namaycush) in Lake Michigan aggregated during spawning. As part of an effort to restore Lake Michigan's lake trout, which were extirpated in the 1950s, yearling lake trout have been released over the MLRC since the mid-1980s and fall gill net censuses began to show large numbers of lake trout in spawning condition beginning about 1999. We report the first evidence of viable egg deposition and successful lake trout fry production at these deep reefs. Because the area's existing bathymetry and habitat were too poorly known for a priori selection of sampling sites, we used hydroacoustics to locate concentrations of large fish in the fall; fish were congregating around slopes and ridges. Subsequent observations via unmanned submersible confirmed the large fish to be lake trout. Our technological objectives were driven by biological objectives of locating where lake trout spawn, where lake trout fry were produced, and what fishes ate lake trout eggs and fry. The unmanned submersibles were equipped with a suction sampler and electroshocker to sample eggs deposited on the reef, draw out and occasionally catch emergent fry, and collect egg predators (slimy sculpin Cottus cognatus). We observed slimy sculpin to eat unusually high numbers of lake trout eggs. Our qualitative approaches are a first step toward quantitative assessments of the importance of lake trout spawning on the MLRC.

  15. Egg fatty acid composition from lake trout fed two Lake Michigan prey fish species. (United States)

    Honeyfield, Dale C; Fitzsimons, John D; Tillitt, Donald E; Brown, Scott B


    We previously demonstrated that there were significant differences in the egg thiamine content in lake trout Salvelinus namaycush fed two Lake Michigan prey fish (alewife Alosa pseudoharengus and bloater Coregonus hoyi). Lake trout fed alewives produced eggs low in thiamine, but it was unknown whether the consumption of alewives affected other nutritionally important components. In this study we investigated the fatty acid composition of lake trout eggs when females were fed diets that resulted in different egg thiamine concentrations. For 2 years, adult lake trout were fed diets consisting of four combinations of captured alewives and bloaters (100% alewives; 65% alewives, 35% bloaters; 35% alewives, 65% bloaters; and 100% bloaters). The alewife fatty acid profile had higher concentrations of arachidonic acid and total omega-6 fatty acids than the bloater profile. The concentrations of four fatty acids (cis-13, 16-docosadienoic, eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) were higher in bloaters than in alewives. Although six fatty acid components were higher in lake trout eggs in 2001 than in 2000 and eight fatty acids were lower, diet had no effect on any fatty acid concentration measured in lake trout eggs in this study. Based on these results, it appears that egg fatty acid concentrations differ between years but that the egg fatty acid profile does not reflect the alewife-bloater mix in the diet of adults. The essential fatty acid content of lake trout eggs from females fed alewives and bloaters appears to be physiologically regulated and adequate to meet the requirements of developing embryos.

  16. Determination of polyfluoroalkyl phosphoric acid diesters, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, perfluoroalkyl carboxylic acids, and perfluoroalkane sulfonic acids in lake trout from the Great Lakes region. (United States)

    Guo, Rui; Reiner, Eric J; Bhavsar, Satyendra P; Helm, Paul A; Mabury, Scott A; Braekevelt, Eric; Tittlemier, Sheryl A


    A comprehensive method to extract perfluoroalkyl carboxylic acids, perfluoroalkane sulfonic acids, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, and polyfluoroalkyl phosphoric acid diesters simultaneously from fish samples has been developed. The recoveries of target compounds ranged from 78 % to 121 %. The new method was used to analyze lake trout (Salvelinus namaycush) from the Great Lakes region. The results showed that the total perfluoroalkane sulfonate concentrations ranged from 0.1 to 145 ng/g (wet weight) with perfluorooctane sulfonate (PFOS) as the dominant contaminant. Concentrations in fish between lakes were in the order of Lakes Ontario ≈ Erie > Huron > Superior ≈ Nipigon. The total perfluoroalkyl carboxylic acid concentrations ranged from 0.2 to 18.2 ng/g wet weight. The aggregate mean perfluorooctanoic acid (PFOA) concentration in fish across all lakes was 0.045 ± 0.023 ng/g. Mean concentrations of PFOA were not significantly different (p > 0.1) among the five lakes. Perfluoroalkyl phosphinic acids were detected in lake trout from Lake Ontario, Lake Erie, and Lake Huron with concentration ranging from non-detect (ND) to 0.032 ng/g. Polyfluoroalkyl phosphoric acid diesters were detected only in lake trout from Lake Huron, at levels similar to perfluorooctanoic acid.

  17. Assessment of Salmonids and their Habitat Conditions in the Walla Walla River Basin within Washington, 2001 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Mendel, Glen Wesley; Trump, Jeremy; Karl, David


    Concerns about the decline of native salmon and trout populations have increased among natural resource managers and the public in recent years. As a result, a multitude of initiatives have been implemented at the local, state, and federal government levels. These initiatives include management plans and actions intended to protect and restore salmonid fishes and their habitats. In 1998 bull trout (Salvelinus confluentus) were listed under the Endangered Species Act (ESA), as ''Threatened'', for the Walla Walla River and its tributaries. Steelhead (Oncorhynchus mykiss) were listed as ''Threatened'' in 1999 for the mid-Columbia River and its tributaries. These ESA listings emphasize the need for information about these threatened salmonid populations and their habitats. The Washington Department of Fish and Wildlife (WDFW) is entrusted with ''the preservation, protection, and perpetuation of fish and wildlife....[and to] maximize public recreational or commercial opportunities without impairing the supply of fish and wildlife (WAC 77.12.010).'' In consideration of this mandate, the WDFW submitted a proposal in December 1997 to the Bonneville Power Administration (BPA) for a study to assess salmonid distribution, relative abundance, genetics, and the condition of salmonid habitats in the Walla Walla River basin. The primary purposes of this project are to collect baseline biological and habitat data, to identify major data gaps, and to draw conclusions whenever possible. The study reported herein details the findings of the 2001 field season (March to November, 2001).

  18. Effects of gill-net trauma, barotrauma, and deep release on postrelease mortality of Lake Trout (United States)

    Ng, Elizabeth L.; Fredericks, Jim P.; Quist, Michael C.


    Unaccounted postrelease mortality violates assumptions of many fisheries studies, thereby biasing parameter estimates and reducing efficiency. We evaluated effects of gill-net trauma, barotrauma, and deep-release treatment on postrelease mortality of lake trout Salvelinus namaycush. Lake trout were captured at depths up to 65 m with gill nets in Priest Lake, Idaho, and held in a large enclosure for 10–12 d. Postrelease mortality was the same for surface-release–and deep-release–treated fish (41%). Mixed-effects logistic regression models were used to evaluate effects of intrinsic and environmental factors on the probability of mortality. Presence of gill-net trauma and degree of barotrauma were associated with increased probability of postrelease mortality. Smaller fish were also more likely to suffer postrelease mortality. On average, deep-release treatment did not reduce postrelease mortality, but effectiveness of treatment increased with fish length. Of the environmental factors evaluated, only elapsed time between lifting the first and last anchors of a gill-net gang (i.e., lift time) was significantly related to postrelease mortality. Longer lift times, which may allow ascending lake trout to acclimate to depressurization, were associated with lower postrelease mortality rates. Our study suggests that postrelease mortality may be higher than previously assumed for lake trout because mortality continues after 48 h. In future studies, postrelease mortality could be reduced by increasing gill-net lift times and increasing mesh size used to increase length of fish captured.

  19. Concerning the preliminary results of space experiment with the seeds of rare plants (on the boad of BION-M No.1) (United States)

    Gorelov, Yury; Kurganskaya, Lubov; Ilyin, Vyacheslav; Ruzaeva, Irina; Rozno, Svetlana; Kavelenova, Ludmila

    species of Samara region (Сlematis integrifolia L.; Aster alpinus L.; Dianthus andrzejowskianus Kulcz.; Linum perenne L.; Polemonium caeruleum L.; Primula macrocalyx Bunge; Iris pumila L.; Lilium martagon L.; Pulsatilla patens (L.) Mill., 8 from 9 are the plants of Samara Region Reed book) were packed into 3 marked plastic test tubes (Ø12/75, 4 ml). After the landing of “Bion-M” the seeds were sown on the experimental plot in the Botanical garden of Samara State University (25 July 2013). The sow time was near to the time of seeds ripening when they can fall on the ground in natural ecosystems. The abundant rains in the beginning of August 2013 made the beneficial conditions for sprouting and the first seedlings we found 10-15 days after sowing. The ground germination parameters varied from 3 to 78% for 6 different species (Сlematis integrifolia L. 3%; Dianthus andrzejowskianus Kulcz. 8%; Pulsatilla patens (L.) Mill 15%; .Linum perenne L. 67%; Polemonium caeruleum L. 75%; Iris pumila L. 78%), whereas 3 species did not sprout for that time (Lilium martagon L.; Aster alpinus L.; Primula macrocalyx Bunge). The most native flora species normally have no synchronic seed germination and many seeds each year are added in soil seed bank. Many ripe seeds are in dormancy that must be removed passing by autumn-winter period. That is a possible reason of seedlings absence in 3 of our species. We can mention the increase of ground germination parameters (comparing with their common germination levels) for Linum perenne L. and Iris pumila L. as a positive (stimulating) effect of space flight factors complex. These seeds normally never demonstrate germination on the level of 70-80%. Also we found the increase of plants diversity on their initial stage of development. Some more developed and big specimens appeared among the seedlings, what more clearly demonstrated Linum perenne L. and Iris pumila L.. Maybe such heterogeneity is connected with different seed mass and size what

  20. Phantom spiders 2: More notes on dubious spider species from Europe

    Directory of Open Access Journals (Sweden)

    Breitling, Rainer


    (Audouin, 1826 syn. nov.; Arctosa brevialva (Franganillo, 1913 = Arctosa villica (Lucas, 1846 syn. nov.; Arctosa cinerea (Franganillo, 1913 [nec Arctosa cinerea (Fabricius, 1777] = Arctosa perita (Latreille, 1799 syn. nov.; Cresmatoneta eleonorae (Costa, 1883 and Cresmatoneta mutinensis orientalis (Strand, 1914 = Cresmatoneta mutinensis (Canestrini, 1868 syn. nov.; Cyclosa conica albifoliata Strand, 1907, Cyclosa conica defoliata Strand, 1907, Cyclosa conica leucomelas Strand, 1907, Cyclosa conica pyrenaica Strand, 1907, Cyclosa conica dimidiata Simon, 1929, Cyclosa conica rubricauda Simon, 1929 and Cyclosa conica triangulifera Simon, 1929 = Cyclosa conica (Pallas, 1772 syn. nov.; Dendryphantes lanipes C.L. Koch, 1846 = Philaeus chrysops (Poda, 1761 syn. nov.; Diplocephalus alpinus strandi Kolosváry, 1937 = Diplocephalus alpinus (O. Pickard-Cambridge, 1872 syn. nov.; Entelecara strandi Kolosváry, 1934 = Nusoncus nasutus (Schenkel, 1925 syn. nov.; Euophrys rosenhaueri L. Koch, 1856 = Menemerus semilimbatus (Hahn, 1829 syn. nov.; Evarcha falcata nigrofusca (Strand, 1900 = Evarcha falcata (Clerck, 1757 syn. nov.; Gibbaranea bituberculata strandiana (Kolosváry, 1936 = Gibbaranea bituberculata (Walckenaer, 1802 syn. nov.; Heliophanus auratus mediocinctus Kulczyński, 1898 = H. mediocinctus Kulczyński, 1898 stat. nov.; Larinioides sclopetarius jacobea (Franganillo, 1910 = Larinioides sclopetarius (Clerck 1757 syn. conf.; Linyphia triangularis juniperina Kolosváry, 1933 = Linyphia triangularis (Clerck, 1757 syn. nov.; Myrmarachne formicaria tyrolensis (C. L. Koch, 1846 = Myrmarachne formicaria (De Geer, 1778 syn. conf.; Nuctenea umbratica obscura (Franganillo, 1909 = Nuctenea umbratica (Clerck, 1757 syn. nov.; Ozyptila strandi Kolosváry, 1939 = Ozyptila confluens (C. L. Koch, 1845 syn. nov.; Panamomops strandi Kolosváry, 1934 = Saloca diceros (O. Pickard-Cambridge, 1871 syn. nov.; Pardosa luctinosa marina (Kolosváry, 1940 and Pardosa luctinosa etsinensis Schenkel, 1963

  1. 基于细胞色素b基因序列分析我国鲑亚科鱼类系统发育关系和不同虹鳟养殖群体遗传变异%Phylogenetic Relationships among Members in Salmoninae and Genetic Variation amongDifferent Populationsof Rainbow Trout Farmedin China Basedon Cytb Sequence

    Institute of Scientific and Technical Information of China (English)



    采用PCR技术扩增了中国不同虹鳟群体的细胞色素b基因,对虹鳟不同养殖群体进行了遗传多样性分析,并与鲑亚科中其他5属11个物种的细胞色素b基因进行同源性比较,建立了主要养殖鲑亚科鱼类的系统关系。试验结果显示,虹鳟种内本地虹鳟群体遗传距离最小(0.001),道氏群体最高(0.004)。种间遗传距离以哲罗鲑与马苏大麻哈鱼的遗传距离最大(0.127),其次为哲罗鲑与银大麻哈鱼(0.123),以远东红点鲑和美洲红点鲑的最近(0.003)。聚类分析表明,同属的鱼均能单独聚类,哲罗鱼属和细鳞鱼属聚在一起,鲑属与红点鲑属聚在一起。虹鳟不同群体间并没有单独聚类,提示不同虹鳟群体间没有发生明显的遗传分化。%The Cytb sequences were amplified by PCR technique ,and genetic diversity was analyzed in different populations of rainbow trout Oncorhynchus mykiss farmed in China . The phylogenetic relationships among members in Salmoninae were established by comparing with the sequences from eleven other species representing five genera in subfamily Salmoninae .The results showed that the local rainbow trout population (0 .001 ) had the minimal intraspecies genetic distance ,and Donaldsons population the maximal (0 .004) .In the interspecies ,however ,there was the maximal genetic distance (0 .127) between taimen Hucho taimen and masou salmon O . masou ,followed by between taimen and coho salmon O . kisutch(0 .123)and the minimal genetic distances between Siberian char Salvelinus leucomaenis and brook trout S .fontinalis (0 .003) .Clustering analysis revealed that fish in the same genus was separately clustered ,lenok Brachymystax and H ucho being clustered together ,and Oncorhynchus and Salvelinus being clustered together .No clustering was observed in the individuals of different rainbow trout populations ,indicating that different populations of rainbow

  2. Starch molecular fractionation of bread wheat varieties Fraccionamiento molecular del almidón de variedades trigo pan

    Directory of Open Access Journals (Sweden)

    V. Corcuera


    Full Text Available The starch composition of bread making wheat seeds (Triticum aestivum subsp. vulgare of the Argentine commercial varieties Buck Charrua, Buck Ombú, Buck Guaraní, Buck Catriel and Buck Poncho was analyzed by two different methods. One of these depends on the differential solubility of amylose and amylopectin in a water:butanol mixture whilst the other process is based on the use of the lectin Concanavalin A. These methods were complemented by spectrophotometric determinations to enable the identification of the á-D- glucanes and also improved the comparative quantitation of the amylose and amylopectin fractions. As a result of this, no significant variations for starch content (ANOVA, F4- 8= 0.7; p ≥ 0.05 were found among these varieties, although strong differences were found for amylose (ANOVA, F4- 8= 44.4; p ≥ 0.01 and amylopectin content (ANOVA, F4- 8= 77.1; p ≥ 0.01. These results and the fact that no differences were found for amylose (ANOVA, F2- 8= 0.3 and amylopectin among years within the same variety (ANOVA, F2- 8:0.8 at p ≥0.01 led to the conclusion that the diverse properties and end-uses of the starch mainly depend on the genotype, and that starch quality is null or scarcely influenced by the environment. This knowledge must be taken into account for wheat breeding purposes.Se analizó la composición del almidón de granos de trigo pan (Triticum aestivum subsp. v u l g a r e de las variedades comerciales argentinas Buck Charrúa, Buck Ombú, Buck Guaraní, Buck Catriel y Buck Poncho mediante dos métodos diferentes. Uno de ellos depende de la solubilidad diferencial de la amilosa y amilopectina en una mezcla de agua:butanol, mientras que el otro proceso está basado en el uso de la lectina Concanavalina A. Estos métodos fueron complementados mediante determinaciones espectrofotométricas que facilitaron la identificación de los á-D-glucanos y también permitieron mejorar la cuantificación comparativa de las fracciones

  3. Decline of shortjaw cisco in Lake Superior: the role of overfishing and risk of extinction (United States)

    Bronte, Charles R.; Hoff, Michael H.; Gorman, Owen T.; Thogmartin, Wayne E.; Schneeberger, Philip J.; Todd, Thomas N.


    Recent reviews have further documented the decline of the shortjaw cisco Coregonus zenithicus in Lake Superior. This fish was the most abundant deepwater cisco species in Lake Superior in the early 1920s but presently makes up less than 1% of all deepwater ciscoes (i.e., including shortjaw cisco, bloater C. hoyi, and kiyi C. kiyi) captured in biological surveys. Directed overfishing of deepwater cisco species during the 1930s and again during the mid-1960s and 1970s has been suggested as the cause of the shortjaw cisco's demise. In this paper, we re-examined the overfishing hypothesis by using historical and recent survey data to estimate the proportion of the historical commercial fishery landings that comprised shortjaw ciscoes. We developed time series of estimated harvest and relative abundance for all statistical districts in Michigan waters of Lake Superior during 1929–1996, for which aggregate catch and effort data were available but not previously examined. The spatial distribution of the fishery and the relationships of catch to fishing effort were examined for evidence of overfishing. Our analysis suggested that directed overfishing was probably not the cause of shortjaw cisco demise, as this species appeared to be declining in all statistical districts regardless of the intensity of the fishery. A count-based population viability analysis indicated that quasi-extinction of the shortjaw cisco is highly probable in the near future. We propose an alternative hypothesis based on the decline of Lake Superior's keystone predator, the lake trout Salvelinus namaycush, which resulted in an expansion of the population of its principal prey, the cisco C. artedi, due to release from predation pressure. Competitive or predation interactions between the cisco and shortjaw cisco may be more likely explanations for the demise of the latter species.

  4. Seasonally dynamic diel vertical migrations of Mysis diluviana, coregonine fishes, and siscowet lake trout in the pelagia of western Lake Superior (United States)

    Ahrenstorff, Tyler D.; Hrabik, Thomas R.; Stockwell, Jason D.; Yule, Daniel L.; Sass, Greg G.


    Diel vertical migrations are common among many aquatic species and are often associated with changing light levels. The underlying mechanisms are generally attributed to optimizing foraging efficiency or growth rates and avoiding predation risk (μ). The objectives of this study were to (1) assess seasonal and interannual changes in vertical migration patterns of three trophic levels in the Lake Superior pelagic food web and (2) examine the mechanisms underlying the observed variability by using models of foraging, growth, and μ. Our results suggest that the opossum shrimp Mysis diluviana, kiyi Coregonus kiyi, and siscowet lake trout Salvelinus namaycush migrate concurrently during each season, but spring migrations are less extensive than summer and fall migrations. In comparison with M. diluviana, kiyis, and siscowets, the migrations by ciscoes C. artedi were not as deep in the water column during the day, regardless of season. Foraging potential and μ probably drive the movement patterns of M. diluviana, while our modeling results indicate that movements by kiyis and ciscoes are related to foraging opportunity and growth potential and receive a lesser influence from μ. The siscowet is an abundant apex predator in the pelagia of Lake Superior and probably undertakes vertical migrations in the water column to optimize foraging efficiency and growth. The concurrent vertical movement patterns of most species are likely to facilitate nutrient transport in this exceedingly oligotrophic ecosystem, and they demonstrate strong linkages between predators and prey. Fishery management strategies should use an ecosystem approach and should consider how altering the densities of long-lived top predators produces cascading effects on the nutrient cycling and energy flow in lower trophic levels.

  5. Shallow bedrock limits groundwater seepage-based headwater climate refugia (United States)

    Briggs, Martin; Lane, John; Snyder, Craig D.; White, Eric A.; Johnson, Zachary; Nelms, David L.; Hitt, Nathaniel P.


    Groundwater/surface-water exchanges in streams are inexorably linked to adjacent aquifer dynamics. As surface-water temperatures continue to increase with climate warming, refugia created by groundwater connectivity is expected to enable cold water fish species to survive. The shallow alluvial aquifers that source groundwater seepage to headwater streams, however, may also be sensitive to seasonal and long-term air temperature dynamics. Depth to bedrock can directly influence shallow aquifer flow and thermal sensitivity, but is typically ill-defined along the stream corridor in steep mountain catchments. We employ rapid, cost-effective passive seismic measurements to evaluate the variable thickness of the shallow colluvial and alluvial aquifer sediments along a headwater stream supporting cold water-dependent brook trout (Salvelinus fontinalis) in Shenandoah National Park, VA, USA. Using a mean depth to bedrock of 2.6 m, numerical models predicted strong sensitivity of shallow aquifer temperature to the downward propagation of surface heat. The annual temperature dynamics (annual signal amplitude attenuation and phase shift) of potential seepage sourced from the shallow modeled aquifer were compared to several years of paired observed stream and air temperature records. Annual stream water temperature patterns were found to lag local air temperature by ∼8–19 d along the stream corridor, indicating that thermal exchange between the stream and shallow groundwater is spatially variable. Locations with greater annual signal phase lag were also associated with locally increased amplitude attenuation, further suggestion of year-round buffering of channel water temperature by groundwater seepage. Numerical models of shallow groundwater temperature that incorporate regional expected climate warming trends indicate that the summer cooling capacity of this groundwater seepage will be reduced over time, and lower-elevation stream sections may no longer serve as larger

  6. Quantitative polymerase chain reaction (PCR) assays for a bacterial thiaminase I gene and the thiaminase-producing bacterium Paenibacillus thiaminolyticus. (United States)

    Richter, C.A.; Wright-Osment, Maureen K.; Zajicek, J.L.; Honeyfield, D.C.; Tillitt, D.E.


    The thiaminase I enzyme produced by the gram-positive bacterium Paenibacillus thiaminolyticus isolated from the viscera of Lake Michigan alewives Alosa pseudoharengus is currently the only defined source of the thiaminase activity linked to thiamine (vitamin B1) deficiency in early mortality syndrome (EMS) in the larvae of Great Lakes salmonines. Diets of alewife or isolated strains of P. thiaminolyticus mixed in a semipurified diet and fed to lake trout Salvelinus namaycush have been shown to produce EMS in fry. We utilized quantitative polymerase chain reaction (Q-PCR) to aid in studies of the sources of P. thiaminolyticus and thiaminase I. Quantitative PCR assays were established to detect the thiaminase I gene of P. thiaminolyticus, the 16S rRNA gene from most species of bacteria, and the 16S rRNA gene specifically from P. thiaminolyticus and a few closely related taxa. The Q-PCR assays are linear over at least six orders of magnitude and can detect the thiaminase I gene of P. thiaminolyticus from as few as 1,000 P. thiaminolyticus cells/g of sample or the Paenibacillus 16S rRNA gene from as few as 100 P. thiaminolyticus cells/g of sample. The initial results from alewife viscera samples with high thiaminase activity yielded unexpectedly low densities of P. thiaminolyticus cells; Paenibacillus thiaminolyticus was detectable in 2 of 6 alewife viscera tested at densities on the order of 100 cells/g out of 100,000,000 total bacterial cells/g. The low numbers of P. thiaminolyticus detected suggest that alewives contain additional non-P. thiaminolyticus sources of thiaminase activity.

  7. Rodent neurotoxicity bioassays for screening contaminated Great Lakes fish

    Energy Technology Data Exchange (ETDEWEB)

    Beattie, M.K.; Hoffman, R. [Univ. of Minnesota, Duluth, MN (United States); Gerstenberger, S. [Univ. of Illinois, Urbana, IL (United States). Dept. of Veterinary Biosciences; Dellinger, J.A. [Medical Coll. of Wisconsin, Milwaukee, MI (United States). Dept. of Preventive Medicine


    Standard laboratory rat neurotoxicity protocols were used to study the consequences resulting from the consumption of walleye (Stizostedion vitreum), whitefish (Coregonus clupeaformis), and lake trout (Salvelinus namaycush) from Lake Superior (LS) and the consumption of carp (Cyprinus carpio) from Little Lake Butte des Morte (LLBM) near Oshkosh, Wisconsin, USA. Two 90-d subchronic studies are described, including a 45-d exposure to fish diets using male Sprague-Dawley hooded rats, and a 90-d exposure to fish diets using female rats of the same species. Behavioral alterations were tested using a battery of behavioral tests. In addition, pharmacologic challenges using apomorphine and D-amphetamine were administered to the rats to reveal latent neurotoxic effects. Cumulative fish consumption data were recorded daily, weight gain recorded weekly, and behavior data collected prior to exposure, and on days 7, 14, 55 {+-} 2, 85 {+-} 2. Motor activity data were collected on days 30 {+-} 2, 60 {+-} 2, and 90 {+-} 2 of the feeding protocols. Brain tissue from rodents fed these fish were subsequently analyzed for either mercury (Hg) or polychlorinated biphenyls (PCB). Mercury concentrations were increased in the brains of the walleye-fed rats, and PCB concentrations ranged from 0.5 nl/L to 10 nl/L in the brains of rats fed carp from LLBM, a Lake Michigan tributary. Adult male rats fed LLBM carp for 45 d exhibited the greatest behavior responses to the dopaminergic agonist apomorphine on the accelerating rotarod, although these differences were not significant. The 90-d exposure of LS walleye or Hg-spiked LS walleye resulted in behavior alterations on tactile startle response and second footsplay. D-Amphetamine challenge caused changes in tactile startle response, second footsplay, and accelerating rotarod performance after consuming walleye diets. Rats fed LLBM carp had altered behavioral responses to apomorphine on the accelerating rotarod.

  8. Exploring crowded trophic niche space in a novel reservoir fish assemblage: how many predators is too many? (United States)

    Winters, Lisa K.; Budy, Phaedra


    In highly managed reservoir systems, species interactions within novel fish assemblages can be difficult to predict. In high-elevation Scofield Reservoir in Utah the unintentional introduction of Utah Chub Gila atraria and subsequent population expansion prompted a shift from stocking exclusively Rainbow Trout Oncorhynchus mykiss to include tiger trout (female Brown Trout Salmo trutta × male Brook Trout Salvelinus fontinalis) and Bonneville Cutthroat Trout O. clarkii utah, which composed a novel suite of top predators and potential competitors. We examined the interspecific interactions among Scofield Reservoir piscivores using a multifaceted approach including gut analyses, stable isotopes, and gape limitation. Large Cutthroat Trout consumed 50–100% Utah Chub and tiger trout consumed 45–80%. In contrast, small and large Rainbow Trout consumed primarily invertebrate prey and exhibited significant overlap with small tiger trout, Cutthroat Trout, and Utah Chub. Large Cutthroat Trout and tiger trout occupy a top piscivore trophic niche and are more littoral, while Rainbow Trout occupy an omnivore niche space and are more pelagic. Both Cutthroat and tiger trout varied in niche space with respect to size-class, demonstrating an ontogenetic shift to piscivory at approximately 350 mm TL. Cutthroat Trout and tiger trout are capable of consuming prey up to 50% of their own size, which is larger than predicted based on their theoretical gape limit. Because it appears food resources (Utah Chub) are not limited, and performance metrics are high, competition is unlikely between Cutthroat Trout and tiger trout. In contrast, apparent survival of Rainbow Trout has recently declined significantly, potentially due to shared food resources with Utah Chub or negative behavioral interactions with other members of the community. Collectively, this research aids in understanding biotic interactions within a top-heavy and novel fish community and assists towards developing

  9. Phylogeny of Salmonidae family inffered from D-loop mitochondrial marker

    Directory of Open Access Journals (Sweden)

    Miad Khalaf


    Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 Salmonids are a heterogeneous group of fish classified in one family – Salmonidae. These species are natives of the northern hemisphere, but currently have been introduced in many countries all over the world for sport fishing and aquaculture. Despite the considerable importance of salmonids, their evolutive history is still a controversial issue. The aim of the current study is to infer the phylogeny within the Salmonidae family using as phylogenetic marker the D-loop region. For this purpose, an PCR amplification of D-loop region, followed by direct sequencing and phylogenetic analysis have been performed in four salmonids species from Romanian fauna - Salmo trutta fario, Salvelinus fontinalis, Thymallus thymallus and Oncorhynchus mykiss. For a more accurate phylogenetic classification of these species within Salmonidae family the analysis included similar sequences from GenBank belonging to 17 salmonid species and an osmerid species used as outgroup. The the phylogenetic trees illustrating the evolutive relationships within Salmonidae were constructed by using Neighbor Joining and Maximum Parsimony methodologies implemented in MEGA5.The phylogenetic analysis using mitochondrial control region as marker has allowed an overview about the positions occupied by Romanian salmonids within the Salmonidae family. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;}

  10. A riverscape perspective of Pacific salmonids and aquatic habitats prior to large-scale dam removal in the Elwha River, Washington, USA (United States)

    Brenkman, S.J.; Duda, J.J.; Torgersen, C.E.; Welty, E.; Pess, G.R.; Peters, R.; McHenry, M.L.


     Dam removal has been increasingly proposed as a river restoration technique. In 2011, two large hydroelectric dams will be removed from Washington State’s Elwha River. Ten anadromous fish populations are expected to recolonise historical habitats after dam removal. A key to understanding watershed recolonisation is the collection of spatially continuous information on fish and aquatic habitats. A riverscape approach with an emphasis on biological data has rarely been applied in mid-sized, wilderness rivers, particularly in consecutive years prior to dam removal. Concurrent snorkel and habitat surveys were conducted from the headwaters to the mouth (rkm 65–0) of the Elwha River in 2007 and 2008. This riverscape approach characterised the spatial extent, assemblage structure and patterns of relative density of Pacific salmonids. The presence of dams influenced the longitudinal patterns of fish assemblages, and species richness was the highest downstream of the dams, where anadromous salmonids still have access. The percent composition of salmonids was similar in both years for rainbow trout, Oncorhynchus mykiss (Walbaum), coastal cutthroat trout, Oncorhynchus clarkii clarkii (Richardson) (89%; 88%), Chinook salmon, Oncorhynchus tshawytscha (Walbaum) (8%; 9%), and bull trout, Salvelinus confluentus (Suckley) (3% in both years). Spatial patterns of abundance for rainbow and cutthroat trout (r = 0.76) and bull trout (r = 0.70) were also consistent between years. Multivariate and univariate methods detected differences in habitat structure along the river profile caused by natural and anthropogenic factors. The riverscape view highlighted species-specific biological hotspots and revealed that 60–69% of federally threatened bull trout occurred near or below the dams. Spatially continuous surveys will be vital in evaluating the effectiveness of upcoming dam removal projects at restoring anadromous salmonids.

  11. Determination of the complete genome sequence of infectious hematopoietic necrosis virus (IHNV) Ch20101008 and viral molecular evolution in China. (United States)

    Jia, Peng; Zheng, Xiao-Cong; Shi, Xiu-Jie; Kan, Shi-Fu; Wang, Jin-Jin; He, Jun-Qiang; Zheng, Wei; Yu, Li; Lan, Wen-Sheng; Hua, Qun-Yi; Liu, Hong; Jin, Ning-Yi


    This study determined the complete genomic sequence of the infectious hematopoietic necrosis virus (IHNV) strain Ch20101008 isolated from farmed brook trout (Salvelinus fontinalis) that died from a disease caused by the virus in northeast China. The sequence was determined from 10 overlapping clones obtained through RT-PCR amplification. The whole genome length of Ch20101008 comprised 11,129 nucleotides (nt), and the overall organization was typical of that observed for all other IHNV strains. The phylogenetic analysis results of the 65 IHNV glycoprotein genes and 47 IHNV partial nucleoprotein genes presented five major genogroups (J, U, L, E and M). The J genogroup included the J Nagano and J Shizuoka subgroups. The IHNV Ch20101008 strain belonged to the J Nagano subgroup of the J genogroup and was significantly related to other Chinese IHNV strains. All Chinese IHNV isolates are monophyletic, with a recent common ancestor, except for the BjLL strain. The N, P, M, G, NV and L genes of Ch20101008 were compared with the available IHNV sequences in GenBank. The results indicated that 198 nt were substituted, 53 of which exhibited amino acid change in the Ch20101008 genome. An adenine nucleotide deletion was found at position 4959 of the 5' UTR of the L gene. In the G gene, specific nucleotides and amino acid variations of the Chinese IHNV strains were observed when compared with 23 isolates from other countries. Of the 15 nucleotide sites that changed, seven resulted in amino acid substitution. The data further demonstrated that the J genogroup IHNV was introduced to and evolved in salmon farm environments in China.

  12. Incorporating movement patterns to improve survival estimates for juvenile bull trout (United States)

    Bowerman, Tracy; Budy, Phaedra


    Populations of many fish species are sensitive to changes in vital rates during early life stages, but our understanding of the factors affecting growth, survival, and movement patterns is often extremely limited for juvenile fish. These critical information gaps are particularly evident for bull trout Salvelinus confluentus, a threatened Pacific Northwest char. We combined several active and passive mark–recapture and resight techniques to assess migration rates and estimate survival for juvenile bull trout (70–170 mm total length). We evaluated the relative performance of multiple survival estimation techniques by comparing results from a common Cormack–Jolly–Seber (CJS) model, the less widely used Barker model, and a simple return rate (an index of survival). Juvenile bull trout of all sizes emigrated from their natal habitat throughout the year, and thereafter migrated up to 50 km downstream. With the CJS model, high emigration rates led to an extreme underestimate of apparent survival, a combined estimate of site fidelity and survival. In contrast, the Barker model, which allows survival and emigration to be modeled as separate parameters, produced estimates of survival that were much less biased than the return rate. Estimates of age-class-specific annual survival from the Barker model based on all available data were 0.218±0.028 (estimate±SE) for age-1 bull trout and 0.231±0.065 for age-2 bull trout. This research demonstrates the importance of incorporating movement patterns into survival analyses, and we provide one of the first field-based estimates of juvenile bull trout annual survival in relatively pristine rearing conditions. These estimates can provide a baseline for comparison with future studies in more impacted systems and will help managers develop reliable stage-structured population models to evaluate future recovery strategies.

  13. Development and evaluation of a bioenergetics model for bull trout (United States)

    Mesa, Matthew G.; Welland, Lisa K.; Christiansen, Helena E.; Sauter, Sally T.; Beauchamp, David A.


    We conducted laboratory experiments to parameterize a bioenergetics model for wild Bull Trout Salvelinus confluentus, estimating the effects of body mass (12–1,117 g) and temperature (3–20°C) on maximum consumption (C max) and standard metabolic rates. The temperature associated with the highest C max was 16°C, and C max showed the characteristic dome-shaped temperature-dependent response. Mass-dependent values of C max (N = 28) at 16°C ranged from 0.03 to 0.13 g·g−1·d−1. The standard metabolic rates of fish (N = 110) ranged from 0.0005 to 0.003 g·O2·g−1·d−1 and increased with increasing temperature but declined with increasing body mass. In two separate evaluation experiments, which were conducted at only one ration level (40% of estimated C max), the model predicted final weights that were, on average, within 1.2 ± 2.5% (mean ± SD) of observed values for fish ranging from 119 to 573 g and within 3.5 ± 4.9% of values for 31–65 g fish. Model-predicted consumption was within 5.5 ± 10.9% of observed values for larger fish and within 12.4 ± 16.0% for smaller fish. Our model should be useful to those dealing with issues currently faced by Bull Trout, such as climate change or alterations in prey availability.

  14. Estimating thermal regimes of bull trout and assessing the potential effects of climate warming on critical habitats (United States)

    Jones, Leslie A.; Muhlfeld, Clint C.; Marshall, Lucy A.; McGlynn, Brian L.; Kershner, Jeffrey L.


    Understanding the vulnerability of aquatic species and habitats under climate change is critical for conservation and management of freshwater systems. Climate warming is predicted to increase water temperatures in freshwater ecosystems worldwide, yet few studies have developed spatially explicit modelling tools for understanding the potential impacts. We parameterized a nonspatial model, a spatial flow-routed model, and a spatial hierarchical model to predict August stream temperatures (22-m resolution) throughout the Flathead River Basin, USA and Canada. Model comparisons showed that the spatial models performed significantly better than the nonspatial model, explaining the spatial autocorrelation found between sites. The spatial hierarchical model explained 82% of the variation in summer mean (August) stream temperatures and was used to estimate thermal regimes for threatened bull trout (Salvelinus confluentus) habitats, one of the most thermally sensitive coldwater species in western North America. The model estimated summer thermal regimes of spawning and rearing habitats at <13 C° and foraging, migrating, and overwintering habitats at <14 C°. To illustrate the useful application of such a model, we simulated climate warming scenarios to quantify potential loss of critical habitats under forecasted climatic conditions. As air and water temperatures continue to increase, our model simulations show that lower portions of the Flathead River Basin drainage (foraging, migrating, and overwintering habitat) may become thermally unsuitable and headwater streams (spawning and rearing) may become isolated because of increasing thermal fragmentation during summer. Model results can be used to focus conservation and management efforts on populations of concern, by identifying critical habitats and assessing thermal changes at a local scale.

  15. Factors influencing the distribution of native bull trout and westslope cutthroat trout in western Glacier National Park, Montana (United States)

    D'Angelo, Vincent S.; Muhlfeld, Clint C.


    The widespread declines of native bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarkii lewisi) populations prompted researchers to investigate factors influencing their distribution and status in western Glacier National Park, Montana. We evaluated the association of a suite of abiotic factors (stream width, elevation, gradient, large woody debris density, pool density, August mean stream temperature, reach surface area) with the occurrence (presence or absence) of bull trout and westslope cutthroat trout in 79 stream reaches in five sub-drainages containing glacial lakes. We modeled the occurrence of each species using logistic regression and evaluated competing models using an information theoretic approach. Westslope cutthroat trout were widely distributed (47 of 79 reaches), and there appeared to be no restrictions on their distribution other than physical barriers. Westslope cutthroat trout were most commonly found in relatively warm reaches downstream of lakes and in headwater reaches with large amounts of large woody debris and abundant pools. By contrast, bull trout were infrequently detected (10 of 79 reaches), with 7 of the 10 (70%) detections in sub-drainages that have not been compromised by non-native lake trout (S. namaycush). Bull trout were most often found in cold, low-gradient reaches upstream of glacial lakes. Our results indicate that complex stream habitats in sub-drainages free of non-native species are important to the persistence of native salmonids in western Glacier National Park. Results from this study may help managers monitor and protect important habitats and populations, inform conservation and recovery programs, and guide non-native species suppression efforts in Glacier National Park and elsewhere.

  16. Genetic diversity is related to climatic variation and vulnerability in threatened bull trout (United States)

    Kovach, Ryan; Muhlfeld, Clint C.; Wade, Alisa A.; Hand, Brian K.; Whited, Diane C.; DeHaan, Patrick W.; Al-Chokhachy, Robert K.; Luikart, Gordon


    Understanding how climatic variation influences ecological and evolutionary processes is crucial for informed conservation decision-making. Nevertheless, few studies have measured how climatic variation influences genetic diversity within populations or how genetic diversity is distributed across space relative to future climatic stress. Here, we tested whether patterns of genetic diversity (allelic richness) were related to climatic variation and habitat features in 130 bull trout (Salvelinus confluentus) populations from 24 watersheds (i.e., ~4–7th order river subbasins) across the Columbia River Basin, USA. We then determined whether bull trout genetic diversity was related to climate vulnerability at the watershed scale, which we quantified on the basis of exposure to future climatic conditions (projected scenarios for the 2040s) and existing habitat complexity. We found a strong gradient in genetic diversity in bull trout populations across the Columbia River Basin, where populations located in the most upstream headwater areas had the greatest genetic diversity. After accounting for spatial patterns with linear mixed models, allelic richness in bull trout populations was positively related to habitat patch size and complexity, and negatively related to maximum summer temperature and the frequency of winter flooding. These relationships strongly suggest that climatic variation influences evolutionary processes in this threatened species and that genetic diversity will likely decrease due to future climate change. Vulnerability at a watershed scale was negatively correlated with average genetic diversity (r = −0.77;P bull trout and other imperiled species. Genetic diversity is already depressed where climatic vulnerability is highest; it will likely erode further in the very places where diversity may be most needed for future persistence.

  17. Comparison of thiaminase activity in fish using the radiometric and 4-nitrothiophenol colorimetric methods (United States)

    Honeyfield, D.C.; Hanes, J.W.; Brown, L.; Kraft, C.E.; Begley, T.P.


    Thiaminase induced thiamine deficiency occurs in fish, humans, livestock and wild animals. A non-radioactive thiaminase assay was described in 2007, but a direct comparison with the radioactive 14C-thiamine method which has been in use for more than 30years has not been reported. The objective was to measure thiaminase activity in forage fish (alewife Alosa pseudoharengus, rainbow smelt Osmerus mordax, and slimy sculpin Cottus cognatus) consumed by predators that manifest thiamine deficiency using both methods. Modifications were made to the colorimetric assay to improve repeatability. Modification included a change in assay pH, enhanced sample clean-up, constant assay temperature (37??C), increase in the concentration of 4-nitrothiophenol (4NTP) and use of a spectrophotometer fitted with a 0.2cm cell. A strong relationship between the two assays was found for 51 alewife (R2=0.85), 36 smelt (R2=0.87) and 20 sculpin (R2=0.82). Thiaminase activity in the colorimetric assay was about 1000 times higher than activity measured by the radioactive method. Application of the assay to fish species from which no thiaminase activity has previously been reported resulted in no 4NTP thiaminase activity being found in bloater Coregonus hoyi, lake trout Salvelinus namaycusch, steelhead trout Oncorhynchus mykiss or Chinook salmon Oncorhynchus tshawytscha. In species previously reported to contain thiaminase, 4NTP thiaminase activity was measured in bacteria Paenibacillus thiaminolyticus, gizzard shad Dorosoma cepedianum, bracken fern Pteridium aquilinum, quagga mussel Dreissena bugensis and zebra mussels D. polymorpha. ?? 2010.

  18. Relationships between water temperatures and upstream migration, cold water refuge use, and spawning of adult bull trout from the Lostine River, Oregon, USA (United States)

    Howell, P.J.; Dunham, J.B.; Sankovich, P.M.


    Understanding thermal habitat use by migratory fish has been limited by difficulties in matching fish locations with water temperatures. To describe spatial and temporal patterns of thermal habitat use by migratory adult bull trout, Salvelinus confluentus, that spawn in the Lostine River, Oregon, we employed a combination of archival temperature tags, radio tags, and thermographs. We also compared temperatures of the tagged fish to ambient water temperatures to determine if the fish were using thermal refuges. The timing and temperatures at which fish moved upstream from overwintering areas to spawning locations varied considerably among individuals. The annual maximum 7-day average daily maximum (7DADM) temperatures of tagged fish were 16-18 ??C and potentially as high as 21 ??C. Maximum 7DADM ambient water temperatures within the range of tagged fish during summer were 18-25 ??C. However, there was no evidence of the tagged fish using localized cold water refuges. Tagged fish appeared to spawn at 7DADM temperatures of 7-14 ??C. Maximum 7DADM temperatures of tagged fish and ambient temperatures at the onset of the spawning period in late August were 11-18 ??C. Water temperatures in most of the upper Lostine River used for spawning and rearing appear to be largely natural since there has been little development, whereas downstream reaches used by migratory bull trout are heavily diverted for irrigation. Although the population effects of these temperatures are unknown, summer temperatures and the higher temperatures observed for spawning fish appear to be at or above the upper range of suitability reported for the species. Published 2009. This article is a US Governmentwork and is in the public domain in the USA.

  19. Assessment of Native Salmonids Above Hells Canyon Dam, Idaho, 2002-2003 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Kevin A.; Lamansky, Jr., James A. (Idaho Department of Fish and Game, Boise, ID)


    We assessed the relationships between specific stream attributes and Yellowstone cutthroat trout Oncorhynchus clarki bouvieri distribution and biomass at 773 stream reaches (averaging 100 m in length) throughout the Upper Snake River Basin in Idaho, in an effort to identify possible limiting factors. Because limiting factors were expected to vary across the range of cutthroat trout distribution in Idaho, separate logistic and multiple regression models were developed for each of the nine major river drainages to relate stream conditions to occurrence and biomass of cutthroat trout. Adequate stream flow to measure fish and habitat existed at 566 sites, and of those, Yellowstone cutthroat trout were present at 322 sites, while rainbow trout O. mykiss (or rainbow x cutthroat hybrids) and brook trout Salvelinus fontinalis occurred at 108 and 181 sites, respectively. In general, cutthroat trout presence at a specific site within a drainage was associated with a higher percentage of public property, higher elevation, more gravel and less fine substrate, and more upright riparian vegetation. However, there was much variation between drainages in the direction and magnitude of the relationships between stream characteristics and Yellowstone cutthroat trout occurrence and biomass, and in model strength. This was especially true for biomass models, in which we were able to develop models for only five drainages that explained more than 50% of the variation in cutthroat trout biomass. Sample size appeared to affect the strength of the biomass models, with a higher explanation of biomass variation in drainages with lower sample sizes. The occurrence of nonnative salmonids was not strongly related to cutthroat trout occurrence, but their widespread distribution and apparent ability to displace native cutthroat trout suggest they may nevertheless pose the largest threat to long-term cutthroat trout persistence in the Upper Snake River Basin.

  20. Wigwam River Juvenile Bull Trout and Fish Habitat Monitoring Program : 2002 Data Report.

    Energy Technology Data Exchange (ETDEWEB)

    Cope, R.S. [Westslope Fisheries, Cranbrook, BC, Canada


    The Wigwam River bull trout (Salvelinus confluentus) and fish habitat monitoring program is a trans-boundary initiative implemented by the British Columbia Ministry of Water, Land, and Air Protection (MWLAP), in cooperation with Bonneville Power Administration (BPA). The Wigwam River is an important fisheries stream located in southeastern British Columbia that supports healthy populations of both bull trout and Westslope cutthroat trout (Figure 1). This river has been characterized as the single most important bull trout spawning stream in the Kootenay Region (Baxter and Westover 2000, Cope 1998). In addition, the Wigwam River supports some of the largest Westslope cutthroat trout (Oncorhynchus clarki lewisi) in the Kootenay Region. These fish are highly sought after by anglers (Westover 1999a, 1999b). Bull trout populations have declined in many areas of their range within Montana and throughout the northwest including British Columbia. Bull trout were blue listed as vulnerable in British Columbia by the B.C. Conservation Data Center (Cannings 1993) and although there are many healthy populations of bull trout in the East Kootenay they remain a species of special concern. Bull trout in the United States portion of the Columbia River were listed as threatened in 1998 under the Endangered Species Act by the U.S. Fish and Wildlife Service. The upper Kootenay River is within the Kootenai sub-basin of the Mountain Columbia Province, one of the eleven Eco-provinces that make up the Columbia River Basin. MWLAP applied for and received funding from BPA to assess and monitor the status of wild, native stocks of bull trout in tributaries to Lake Koocanusa (Libby Reservoir) and the upper Kootenay River. This task is one of many that were undertaken to ''Monitor and Protect Bull Trout for Koocanusa Reservoir'' (BPA Project Number 2000-04-00).

  1. Wigwam River Juvenile Bull Trout and Fish Habitat Monitoring Program : 2000 Data Report.

    Energy Technology Data Exchange (ETDEWEB)

    Cope, R.S.; Morris, K.J.


    The Wigwam River bull trout (Salvelinus confluentus) and fish habitat monitoring program is a trans-boundary initiative implemented by the British Columbia Ministry of Environment, Lands and Parks (MOE), in cooperation with Bonneville Power Administration (BPA). The Wigwam River is an important fisheries stream located in southeastern British Columbia that supports healthy populations of both bull trout and Westslope cutthroat trout (Figure 1.1). This river has been characterized as the single most important bull trout spawning stream in the Kootenay Region (Baxter and Westover 2000, Cope 1998). In addition, the Wigwam River supports some of the largest Westslope cutthroat trout (Oncorhynchus clarki lewisi) in the Kootenay Region. These fish are highly sought after by anglers (Westover 1999a, 1999b). Bull trout populations have declined in many areas of their range within Montana and throughout the northwest including British Columbia. Bull trout were blue listed as vulnerable in British Columbia by the B.C. Conservation Data Center (Cannings 1993) and although there are many healthy populations of bull trout in the East Kootenays they remain a species of special concern. Bull trout in the United States portion of the Columbia River were listed as threatened in 1998 under the Endangered Species Act by the U.S. Fish and Wildlife Service. The upper Kootenay River is within the Kootenai sub-basin of the Mountain Columbia Province, one of the eleven Eco-provinces that make up the Columbia River Basin. MOE applied for and received funding from BPA to assess and monitor the status of wild, native stocks of bull trout in tributaries to Lake Koocanusa (Libby Reservoir) and the upper Kootenay River. This task is one of many that was undertaken to ''Monitor and Protect Bull Trout for Koocanusa Reservoir'' (BPA Project Number 2000-04-00).

  2. Evaluation of offshore stocking of Lake Trout in Lake Ontario (United States)

    Lantry, B.F.; O'Gorman, R.; Strang, T.G.; Lantry, J.R.; Connerton, M.J.; Schanger, T.


    Restoration stocking of hatchery-reared lake trout Salvelinus namaycush has occurred in Lake Ontario since 1973. In U.S. waters, fish stocked through 1990 survived well and built a large adult population. Survival of yearlings stocked from shore declined during 1990–1995, and adult numbers fell during 1998–2005. Offshore stocking of lake trout was initiated in the late 1990s in response to its successful mitigation of predation losses to double-crested cormorants Phalacrocorax auritus and the results of earlier studies that suggested it would enhance survival in some cases. The current study was designed to test the relative effectiveness of three stocking methods at a time when poststocking survival for lake trout was quite low and losses due to fish predators was a suspected factor. The stocking methods tested during 2000–2002 included May offshore, May onshore, and June onshore. Visual observations during nearshore stockings and hydroacoustic observations of offshore stockings indicated that release methods were not a direct cause of fish mortality. Experimental stockings were replicated for 3 years at one site in the southwest and for 2 years at one site in the southeast. Offshore releases used a landing craft to transport hatchery trucks from 3 to 6 km offshore out to 55–60-m-deep water. For the southwest site, offshore stocking significantly enhanced poststocking survival. Among the three methods, survival ratios were 1.74 : 1.00 : 1.02 (May offshore : May onshore : June onshore). Although not statistically significant owing to the small samples, the trends were similar for the southeast site, with survival ratios of 1.67 : 1.00 : 0.72. Consistent trends across years and sites indicated that offshore stocking of yearling lake trout during 2000–2002 provided nearly a twofold enhancement in survival; however, this increase does not appear to be great enough to achieve the 12-fold enhancement necessary to return population abundance to restoration

  3. Maternal characteristics versus egg size and energy density: do stocked lake trout in Lake Ontario experience premature reproductive senescence? (United States)

    Lantry, B.F.; O'Gorman, R.; Machut, L.S.


    Observations from September 1994 and 1997 collections of hatchery-origin, mature female lake trout (Salvelinus namaycush) from Lake Ontario indicated that egg mass decreased with age, fueling the notion that stocked fish experienced premature reproductive senescence. Supplemental collections during September 2002 and November 2002-2004 were combined with the 1994 and 1997 samples to examine whether sample date or maternal age, body mass, condition (K), egg count, or strain were related to egg mass or energy content (percentage dry mass [%DM]). Body mass was correlated with egg mass for age ≥ 8 lake trout sampled in September, and egg count was correlated with egg mass for September age-6 lake trout only. Within each month, egg mass was not related to K or egg %DM, however, egg %DM was 1.52% greater (P ≤ 0.0247) in November than in September which is equivalent to a 110 cal/g difference. Samples were grouped for the three most abundant strains (Seneca, Superior, and Ontario) after finding no strain or year effects from our 1994 and 1997 samples and based on life history data from the literature and our assessment sampling. Further analysis indicated that September egg masses were greater for fish ages ≤ 6 than for fish ages ≥ 8. The age effect disappeared in November when mean egg mass across all ages (0.078 g) was greater than September means (P < 0.0005) for ages -5 (0.054 g), -6 (0.057 g) and ≥ 8 (0.041 g). Our results indicate that the decrease in egg mass with female age in September was not due to senescence, but to oogenesis being closer to completion in young age-5 and -6 fish than in older individuals.

  4. Combining demographic and genetic factors to assess population vulnerability in stream species (United States)

    Erin L, Landguth; Muhlfeld, Clint C.; Jones, Leslie W.; Waples, Robin S.; Whited, Diane; Lowe, Winsor H.; Lucotch, John; Neville, Helen; Luikart, Gordon


    Accelerating climate change and other cumulative stressors create an urgent need to understand the influence of environmental variation and landscape features on the connectivity and vulnerability of freshwater species. Here, we introduce a novel modeling framework for aquatic systems that integrates spatially explicit, individual-based, demographic and genetic (demogenetic) assessments with environmental variables. To show its potential utility, we simulated a hypothetical network of 19 migratory riverine populations (e.g., salmonids) using a riverscape connectivity and demogenetic model (CDFISH). We assessed how stream resistance to movement (a function of water temperature, fluvial distance, and physical barriers) might influence demogenetic connectivity, and hence, population vulnerability. We present demographic metrics (abundance, immigration, and change in abundance) and genetic metrics (diversity, differentiation, and change in differentiation), and combine them into a single vulnerability index for identifying populations at risk of extirpation. We considered four realistic scenarios that illustrate the relative sensitivity of these metrics for early detection of reduced connectivity: (1) maximum resistance due to high water temperatures throughout the network, (2) minimum resistance due to low water temperatures throughout the network, (3) increased resistance at a tributary junction caused by a partial barrier, and (4) complete isolation of a tributary, leaving resident individuals only. We then applied this demogenetic framework using empirical data for a bull trout (Salvelinus confluentus) metapopulation in the upper Flathead River system, Canada and USA, to assess how current and predicted future stream warming may influence population vulnerability. Results suggest that warmer water temperatures and associated barriers to movement (e.g., low flows, dewatering) are predicted to fragment suitable habitat for migratory salmonids, resulting in the loss

  5. Fate of PBDEs in juvenile lake trout estimated using a dynamic multichemical fish model. (United States)

    Bhavsar, Satyendra P; Gandhi, Nilima; Gewurtz, Sarah B; Tomy, Gregg T


    Biotransformation half-lives (HL) and gut absorption efficiencies (GAE) of PBDE congeners in fish are poorly known and challenging to quantify experimentally. These values are needed in order to accurately assess their food web dynamics, and in turn, for policy development We recently developed a multichemical aquatic food web model, which was used to estimate HL of four PBDE congeners in a simple Arctic food web. However, an application of this model to more complex food webs would dramatically increase the uncertainties in the results due to the large number of unknowns that would need to be considered simultaneously. As such, an in-depth analysis of possible HL and GAE of additional PBDE congeners at the scale of individual fish species would facilitate model application to more complex food webs. For this purpose, we developed a fugacity-based dynamic multichemical fish model and applied it to previously published experimental laboratory data. The model was calibrated by maximizing correspondence between the modeled and observed concentrations for each of the thirteen congeners at two dietary concentrations in juvenile lake trout (Salvelinus namaycush) during uptake and depuration phases mainly by varying HL and GAE. A robust parametrization and calibration procedure gave us confidence in our back-calculated congener-specific HL of 42-420 days and GAE of 20-45%. These values can be used as a starting point for model applications to natural fish populations. The fate/transport results suggest that not only loss of PBDE congeners via degradation, but also input through biotransformation of higher brominated congeners, should be accounted for in order to accurately portray dynamics of PBDEs in fish.

  6. Coupling age-structured stock assessment and fish bioenergetics models: a system of time-varying models for quantifying piscivory patterns during the rapid trophic shift in the main basin of Lake Huron (United States)

    He, Ji X.; Bence, James R.; Madenjian, Charles P.; Pothoven, Steven A.; Dobiesz, Norine E.; Fielder, David G.; Johnson, James E.; Ebener, Mark P.; Cottrill, Adam R.; Mohr, Lloyd C.; Koproski, Scott R.


    We quantified piscivory patterns in the main basin of Lake Huron during 1984–2010 and found that the biomass transfer from prey fish to piscivores remained consistently high despite the rapid major trophic shift in the food webs. We coupled age-structured stock assessment models and fish bioenergetics models for lake trout (Salvelinus namaycush), Chinook salmon (Oncorhynchus tshawytscha), walleye (Sander vitreus), and lake whitefish (Coregonus clupeaformis). The model system also included time-varying parameters or variables of growth, length–mass relations, maturity schedules, energy density, and diets. These time-varying models reflected the dynamic connections that a fish cohort responded to year-to-year ecosystem changes at different ages and body sizes. We found that the ratio of annual predation by lake trout, Chinook salmon, and walleye combined with the biomass indices of age-1 and older alewives (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) increased more than tenfold during 1987–2010, and such increases in predation pressure were structured by relatively stable biomass of the three piscivores and stepwise declines in the biomass of alewives and rainbow smelt. The piscivore stability was supported by the use of alternative energy pathways and changes in relative composition of the three piscivores. In addition, lake whitefish became a new piscivore by feeding on round goby (Neogobius melanostomus). Their total fish consumption rivaled that of the other piscivores combined, although fish were still a modest proportion of their diet. Overall, the use of alternative energy pathways by piscivores allowed the increases in predation pressure on dominant diet species.

  7. Landscape models of brook trout abundance and distribution in lotic habitat with field validation (United States)

    McKenna, James E.; Johnson, James H.


    Brook trout Salvelinus fontinalis are native fish in decline owing to environmental changes. Predictions of their potential distribution and a better understanding of their relationship to habitat conditions would enhance the management and conservation of this valuable species. We used over 7,800 brook trout observations throughout New York State and georeferenced, multiscale landscape condition data to develop four regionally specific artificial neural network models to predict brook trout abundance in rivers and streams. Land cover data provided a general signature of human activity, but other habitat variables were resistant to anthropogenic changes (i.e., changing on a geological time scale). The resulting models predict the potential for any stream to support brook trout. The models were validated by holding 20% of the data out as a test set and by comparison with additional field collections from a variety of habitat types. The models performed well, explaining more than 90% of data variability. Errors were often associated with small spatial displacements of predicted values. When compared with the additional field collections (39 sites), 92% of the predictions were off by only a single class from the field-observed abundances. Among “least-disturbed” field collection sites, all predictions were correct or off by a single abundance class, except for one where brown trout Salmo trutta were present. Other degrading factors were evident at most sites where brook trout were absent or less abundant than predicted. The most important habitat variables included landscape slope, stream and drainage network sizes, water temperature, and extent of forest cover. Predicted brook trout abundances were applied to all New York streams, providing a synoptic map of the distribution of brook trout habitat potential. These fish models set benchmarks of best potential for streams to support brook trout under broad-scale human influences and can assist with planning and

  8. Physical, biotic, and sampling influences on diel habitat use by stream-dwelling bull trout (United States)

    Banish, N.P.; Peterson, J.T.; Thurow, R.F.


    We used daytime and nighttime underwater observation to assess microhabitat use by bull trout Salvelinus confluentus (N = 213) in streams of the intermountain western USA during the summers of 2001 and 2002. We recorded fish focal points and measured a set of habitat characteristics as well as habitat availability via line transects. Bull trout were benthic and solitary; most (88%) were observed at night. We developed a conditional logistic regression model to account for the effect of fish movement in response to snorkeling, and we fitted 18 candidate models to evaluate the relative influences of biotic and abiotic factors on habitat use. The candidate models were also fitted with a naive logistic regression (i.e., no movement) to evaluate the effects of movement on inferences of microhabitat use. The most plausible model describing bull trout habitat use was the same for the conditional and nai??ve regressions and included depth, velocity, percent rubble substratum, and the day X depth, body size X depth, and body size X day X depth interactions. The presence of brook trout S. fontinalis and the abundance of conspecifics did not strongly influence microhabitat use by bull trout. The relative rankings of the remaining models differed substantially between the conditional and nai??ve models. Relative to the conditional models, the naive models overestimated the importance of diurnal differences in habitat use and overestimated the use of deepwater habitats, particularly during the day. Both model types suggested that all sizes of bull trout were generally found in deeper, low-velocity habitat at night, whereas small bull trout (70-90 mm total length) were found in shallower habitats during the day. We recommend lhat biologists account for fish movement in response to sampling to avoid biasing modeled habitat use patterns by bull trout. ?? Copyright by the American Fisheries Society 2008.

  9. Use of a seismic air gun to reduce survival of nonnative lake trout embryos: A tool for conservation? (United States)

    Cox, B.S.; Dux, A.M.; Quist, M.C.; Guy, C.S.


    The detrimental impacts of nonnative lake trout Salvelinus namaycush in the western USA have prompted natural resource management agencies in several states to implement lake trout suppression programs. Currently, these programs rely on mechanical removal methods (i.e., gill nets, trap nets, and angling) to capture subadult and adult lake trout. We conducted a study to explore the potential for using high-intensity sound from a relatively small (655.5 cm3 [40 in3]) seismic air gun to reduce survival of lake trout embryos. Lake trout embryos at multiple stages of development were exposed to a single discharge of the seismic air gun at two depths (5 and 15 m) and at two distances from the air gun (0.1 and 2.7 m). Control groups for each developmental stage, distance, and depth were treated identically except that the air gun was not discharged. Mortality in lake trout embryos treated at 0.1 m from the air gun was 100% at 74 daily temperature units in degrees Celsius (TU°C) at both depths. Median mortality in lake trout embryos treated at 0.1 m from the air gun at 207 TU°C (93%) and 267 °C (78%) appeared to be higher than that of controls (49% and 48%, respectively) at 15-m depth. Among the four lake trout developmental stages, exposure to the air gun at 0.1 m resulted in acute mortality up to 60% greater than that of controls. Mortality at a distance of 2.7 m did not appear to differ from that of controls at any developmental stage or at either depth. Our results indicate that seismic air guns have potential as an alternative tool for controlling nonnative lake trout, but further investigation is warranted.

  10. A comparative and experimental evaluation of performance of stocked diploid and triploid brook trout (United States)

    Budy, Phaedra E.; Thiede, G.P.; Dean, A.; Olsen, D.; Rowley, G.


    Despite numerous negative impacts, nonnative trout are still being stocked to provide economically and socially valuable sport fisheries in western mountain lakes. We evaluated relative performance and potential differences in feeding strategy and competitive ability of triploid versus diploid brook trout Salvelinus fontinalis in alpine lakes, as well as behavioral and performance differences of diploid and triploid brook trout in two controlled experimental settings: behavioral experiments in the laboratory and performance evaluations in ponds. Across lakes, catch per unit effort (CPUE) and relative weight (Wr ) were not significantly different between ploidy levels. Mean sizes were also similar between ploidy levels except in two of the larger lakes where diploids attained slightly larger sizes (approximately 20 mm longer). We observed no significant differences between diploids and triploids in diet, diet preference, or trophic structure. Similarly, growth and condition did not differ between ploidy levels in smaller-scale pond experiments, and aggressive behavior did not differ between ploidy levels (fed or unfed fish trials) in the laboratory. Independent of ploidy level, the relative performance of brook trout varied widely among lakes, a pattern that appeared to be a function of lake size or a factor that covaries with lake size such as temperature regime or carrying capacity. In summary, we observed no significant differences in the relative performance of brook trout from either ploidy level across a number of indices, systems, and environmental conditions, nor any indication that one group is more aggressive or a superior competitor than the other. Collectively, these results suggest that triploid brook trout will offer a more risk-averse and promising management opportunity when they are stocked to these lakes and elsewhere to simultaneously meet the needs for the sport fishery and conservation objectives.

  11. Biochemistry and metabolism of lake trout: laboratory and field studies on the effects of contaminants (United States)

    Passino, Dora R. May


    To evaluate the effects of ambient and higher concentrations of PCB's (Aroclor 1254) and DDE in food and water on fry of lake trout (Salvelinus namaycush) from Lake Michigan, I measured several biochemical indicators of stress in exposed and unexposed (control) fry. No differences between treatments were observed in oxygen consumption rates or lactate concentrations of unexercised fry, but apparent differences in specific swimming speed and lactate response in fry that swam to exhaustion suggested that exposed fry had lower stamina. Observed differences between biochemical profiles of 1-day-old sac fry reared from eggs originating from lake trout collected off Saugatuck and those originating from eggs of brood stock at the Marquette (Michigan) hatchery may have been caused by organochlorine contamination or by genetic and dietary differences between the parental stocks. Activity of the enzyme allantoinase was measured in juvenile and adult lake trout as an indicator of sublethal effects of Great Lakes contaminants. The 50% inhibition of allantoinase in vitro occurred at 6.0 mg/L Cu++, 6.7 mg/L Cd++, 34 mg/L Hg++, and 52 mg/L Pb++. Allantoinase was not affected by in vitro exposure to PCB's up to 7 μg/g, or DDE or DDT up to 10 μg/g; however, in vivo exposure resulting in 2.6 μg/g PCB's in the whole fish activated allantoinase slightly (10% significance level). Allantoinase activity was negatively correlated with total length for fish from Lake Michigan but not for fish from Lake Superior or from laboratory stocks. Mercury, PCB's, and DDT, possibly acting in combination with each other and with additional contaminants, may be the cause of the negative correlation of allantoinase activity with size in Lake Michigan lake trout.

  12. Classifying sea lamprey marks on Great Lakes lake trout: observer agreement, evidence on healing times between classes and recommendations for reporting of marking statistics (United States)

    Ebener, Mark P.; Bence, James R.; Bergstedt, Roger A.; Mullet, Katherine M.


    In 1997 and 1998 two workshops were held to evaluate how consistent observers were at classifying sea lamprey (Petromyzon marinus) marks on Great Lakes lake trout (Salvelinus namaycush) as described in the King classification system. Two trials were held at each workshop, with group discussion between trials. Variation in counting and classifying marks was considerable, such that reporting rates for A1–A3 marks varied two to three-fold among observers of the same lake trout. Observer variation was greater for classification of healing or healed marks than for fresh marks. The workshops highlighted, as causes for inconsistent mark classification, both departures from the accepted protocol for classifying marks by some agencies, and differences in how sliding and multiple marks were interpreted. Group discussions led to greater agreement in classifying marks. We recommend ways to improve the reliability of marking statistics, including the use of a dichotomous key to classify marks. Laboratory data show that healing times of marks on lake trout were much longer at 4°C and 1°C than at 10°C and varied greatly among individuals. Reported A1–A3 and B1–B3 marks observed in late summer and fall collections likely result from a mixture of attacks by two year classes of sea lamprey. It is likely that a substantial but highly uncertain proportion of attacks that occur in late summer and fall lead to marks that are classified as A1–A3 the next spring. We recommend additional research on mark stage duration.

  13. Evaluation of an Unsuccessful Brook Trout Electrofishing Removal Project in a Small Rocky Mountain Stream.

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Kevin A.; Lamansky, Jr., James A.; Schill, Daniel J.


    In the western United States, exotic brook trout Salvelinus fontinalis frequently have a deleterious effect on native salmonids, and biologists often attempt to remove brook trout from streams by means of electrofishing. Although the success of such projects typically is low, few studies have assessed the underlying mechanisms of failure, especially in terms of compensatory responses. A multiagency watershed advisory group (WAG) conducted a 3-year removal project to reduce brook trout and enhance native salmonids in 7.8 km of a southwestern Idaho stream. We evaluated the costs and success of their project in suppressing brook trout and looked for brook trout compensatory responses, such as decreased natural mortality, increased growth, increased fecundity at length, and earlier maturation. The total number of brook trout removed was 1,401 in 1998, 1,241 in 1999, and 890 in 2000; removal constituted an estimated 88% of the total number of brook trout in the stream in 1999 and 79% in 2000. Although abundance of age-1 and older brook trout declined slightly during and after the removals, abundance of age-0 brook trout increased 789% in the entire stream 2 years after the removals ceased. Total annual survival rate for age-2 and older brook trout did not decrease during the removals, and the removals failed to produce an increase in the abundance of native redband trout Oncorhynchus mykiss gairdneri. Lack of a meaningful decline and unchanged total mortality for older brook trout during the removals suggest that a compensatory response occurred in the brook trout population via reduced natural mortality, which offset the removal of large numbers of brook trout. Although we applaud WAG personnel for their goal of enhancing native salmonids by suppressing brook trout via electrofishing removal, we conclude that their efforts were unsuccessful and suggest that similar future projects elsewhere over such large stream lengths would be costly, quixotic enterprises.

  14. Kootenai River Fisheries Investigations: Salmonid Studies Project Progress Report, 2007-2008 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Paragamian, Vaughn L.; Walters, Jody; Maiolie, Melo [Idaho Department of Fish and Game


    This research report addresses bull trout Salvelinus confluentus and Redband trout Oncorhynchus mykiss redd surveys, population monitoring, trout distribution, and abundance surveys in the Kootenai River drainage of Idaho. The bull trout is one of several sport fish native to the Kootenai River, Idaho that no longer supports a fishery. Because bull trout are listed under the Endangered Species Act, population data will be vital to monitoring status relative to recovery goals. Thirty-three bull trout redds were found in North and South Callahan creeks and Boulder Creek in 2007. This is a decrease from 2006 and 2005 and less than the high count in 2003. However, because redd numbers have only been monitored since 2002, the data series is too short to determine bull trout population trends based on redd counts. Redband trout still provide an important Kootenai River sport fishery, but densities are low, at least partly due to limited recruitment. The redband trout proportional stock density (PSD) in 2007 increased from 2006 for a second year after a two-year decline in 2004 and 2005. This may indicate increased recruitment to or survival in the 201-305 mm length group due to the minimum 406 mm (16 inches) length limit initiated in 2002. We conducted 13 redd surveys and counted 44 redband trout redds from May 7 to June 3, 2007 in a 3.8 km survey reach on Twentymile Creek. We surveyed streams in the Kootenai River valley to look for barriers to trout migration. Man-made barriers, for at least part of the year, were found on Caboose, Debt, Fisher, and Twenty Mile creeks. Removing these barriers would increase spawning and rearing habitat for trout and help to restore trout fisheries in the Kootenai River.

  15. Modeling prey consumption by native and non-native piscivorous fishes: implications for competition and impacts on shared prey in an ultraoligotrophic lake in Patagonia (United States)

    Juncos, Romina; Beauchamp, David A.; Viglianoc, Pablo H.


    We examined trophic interactions of the nonnative salmonids Rainbow Trout Oncorhynchus mykiss, Brown Trout Salmo trutta, and Brook Trout Salvelinus fontinalisand the main native predator Creole Perch Percichthys trucha in Lake Nahuel Huapi (Patagonia, Argentina) to determine the relative impact of each predator on their forage base and to evaluate the potential vulnerability of each predator to competitive impacts by the others. Using bioenergetics simulations, we demonstrated the overall importance of galaxiids and decapods to the energy budgets of nonnative salmonids and Creole Perch. Introduced salmonids, especially Rainbow Trout, exerted considerably heavier predatory demands on shared resources than did the native Creole Perch on both a per capita basis and in terms of relative population impacts. Rainbow Trout consumed higher quantities and a wider size range of Small Puyen (also known as Inanga) Galaxias maculatus than the other predators, including early pelagic life stages of that prey; as such, this represents an additional source of mortality for the vulnerable early life stages of Small Puyen before and during their transition from pelagic to benthic habitats. All predators were generally feeding at high feeding rates (above 40% of their maximum physiological rates), suggesting that competition for prey does not currently limit either Creole Perch or the salmonids in this lake. This study highlights the importance of keystone prey for the coexistence of native species with nonnative top predators. It provides new quantitative and qualitative evidence of the high predation pressure exerted on Small Puyen, the keystone prey species, during the larval to juvenile transition from pelagic to littoral-benthic habitat in Patagonian lakes. This study also emphasizes the importance of monitoring salmonid and Creole Perch population dynamics in order to detect signs of potential impacts through competition and shows the need to carefully consider the rationale

  16. Physiological response of some economically important freshwater salmonids to catch-and-release fishing (United States)

    Wedemeyer, G.A.; Wydoski, R.S.


    Catch-and-release fishing regulations are widely used by fishery resource managers to maintain both the quantity and quality of sport fish populations. We evaluated blood chemistry disturbances in wild brook trout Salvelinus fontinalis, brown trout Salmo trutta, cutthroat trout Oncorhynchus clarkii, and Arctic grayling Thymallus arcticus that had been hooked and played for 1-5 min in waters of the intermountain western United States. A hatchery stock of brown trout was included for comparison. To assess time needed for recovery, additional test groups were played for 5 min and then released into net-pens, where they were held for up to 72 h. The osmoregulatory and metabolic disturbances associated with catch-and-release fishing under the conditions we tested were minimal and judged to be well within normal physiological tolerance limits. In fish that were held for recovery, the blood chemistry alterations that did occur appeared to be related to stress from confinement in the net-pens. Our results confirm the results of previous studies, showing that prerelease air exposure and handling cause more physiological stress than does either hooking per se or playing time. Fishery managers must be aware of the differences in the perceptions, attitudes, and values of different societal groups, some of which feel that catch-and-release fishing should be banned because it is cruel to the animals. On the basis of brain anatomy, it seems highly unlikely that fish experience pain in the same manner as humans experience it, because fish lack a neocortex, the brain structure that enables the sensation of pain in higher vertebrates. However, independent of the neurobiological argument, our results indicate that under conditions similar to those tested, fish subjected to catch and release are neither suffering nor particularly stressed. Improved education programs about the relatively benign physiological effects of catch-and-release fishing as a fishery management practice would

  17. Climate, invasive species and land use drive population dynamics of a cold-water specialist (United States)

    Kovach, Ryan P.; Al-Chokhachy, Robert K.; Whited, Diane C.; Schmetterling, David A.; Dux, Andrew M; Muhlfeld, Clint C.


    Climate change is an additional stressor in a complex suite of threats facing freshwater biodiversity, particularly for cold-water fishes. Research addressing the consequences of climate change on cold-water fish has generally focused on temperature limits defining spatial distributions, largely ignoring how climatic variation influences population dynamics in the context of other existing stressors.We used long-term data from 92 populations of bull trout Salvelinus confluentus – one of North America's most cold-adapted fishes – to quantify additive and interactive effects of climate, invasive species and land use on population dynamics (abundance, variability and growth rate).Populations were generally depressed, more variable and declining where spawning and rearing stream habitat was limited, invasive species and land use were prevalent and stream temperatures were highest. Increasing stream temperature acted additively and independently, whereas land use and invasive species had additive and interactive effects (i.e. the impact of one stressor depended on exposure to the other stressor).Most (58%–78%) of the explained variation in population dynamics was attributed to the presence of invasive species, differences in life history and management actions in foraging habitats in rivers, lakes and reservoirs. Although invasive fishes had strong negative effects on populations in foraging habitats, proactive control programmes appeared to effectively temper their negative impact.Synthesis and applications. Long-term demographic data emphasize that climate warming will exacerbate imperilment of cold-water specialists like bull trout, yet other stressors – especially invasive fishes – are immediate threats that can be addressed by proactive management actions. Therefore, climate-adaptation strategies for freshwater biodiversity should consider existing abiotic and biotic stressors, some of which provide potential and realized opportunity for conservation

  18. Do low-mercury terrestrial resources subsidize low-mercury growth of stream fish? Differences between species along a productivity gradient.

    Directory of Open Access Journals (Sweden)

    Darren M Ward

    Full Text Available Low productivity in aquatic ecosystems is associated with reduced individual growth of fish and increased concentrations of methylmercury (MeHg in fish and their prey. However, many stream-dwelling fish species can use terrestrially-derived food resources, potentially subsidizing growth at low-productivity sites, and, because terrestrial resources have lower MeHg concentrations than aquatic resources, preventing an increase in diet-borne MeHg accumulation. We used a large-scale field study to evaluate relationships among terrestrial subsidy use, growth, and MeHg concentrations in two stream-dwelling fish species across an in-stream productivity gradient. We sampled young-of-the-year brook trout (Salvelinus fontinalis and Atlantic salmon (Salmo salar, potential competitors with similar foraging habits, from 20 study sites in streams in New Hampshire and Massachusetts that encompassed a wide range of aquatic prey biomass. Stable isotope analysis showed that brook trout used more terrestrial resources than Atlantic salmon. Over their first growing season, Atlantic salmon tended to grow larger than brook trout at sites with high aquatic prey biomass, but brook grew two-fold larger than Atlantic salmon at sites with low aquatic prey biomass. The MeHg concentrations of brook trout and Atlantic salmon were similar at sites with high aquatic prey biomass and the MeHg concentrations of both species increased at sites with low prey biomass and high MeHg in aquatic prey. However, brook trout had three-fold lower MeHg concentrations than Atlantic salmon at low-productivity, high-MeHg sites. These results suggest that differential use of terrestrial resource subsidies reversed the growth asymmetry between potential competitors across a productivity gradient and, for one species, moderated the effect of low in-stream productivity on MeHg accumulation.

  19. Broad-scale patterns of Brook Trout responses to introduced Brown Trout in New York (United States)

    McKenna, James E.; Slattery, Michael T.; Kean M. Clifford,


    Brook Trout Salvelinus fontinalis and Brown Trout Salmo trutta are valuable sport fish that coexist in many parts of the world due to stocking introductions. Causes for the decline of Brook Trout within their native range are not clear but include competition with Brown Trout, habitat alteration, and repetitive stocking practices. New York State contains a large portion of the Brook Trout's native range, where both species are maintained by stocking and other management actions. We used artificial neural network models, regression, principal components analysis, and simulation to evaluate the effects of Brown Trout, environmental conditions, and stocking on the distribution of Brook Trout in the center of their native range. We found evidence for the decline of Brook Trout in the presence of Brown Trout across many watersheds; 22% of sampled reaches where both species were expected to occur contained only Brown Trout. However, a model of the direct relationship between Brook Trout and Brown Trout abundance explained less than 1% of data variation. Ordination showed extensive overlap of Brook Trout and Brown Trout habitat conditions, with only small components of the hypervolume (multidimensional space) being distinctive. Subsequent analysis indicated higher abundances of Brook Trout in highly forested areas, while Brown Trout were more abundant in areas with relatively high proportions of agriculture. Simulation results indicated that direct interactions and habitat conditions were relatively minor factors compared with the effects of repeated stocking of Brown Trout into Brook Trout habitat. Intensive annual stocking of Brown Trout could eliminate resident Brook Trout in less than a decade. Ecological differences, harvest behavior, and other habitat changes can exacerbate Brook Trout losses. Custom stocking scenarios with Brown Trout introductions at relatively low proportions of resident Brook Trout populations may be able to sustain healthy populations of both

  20. Evaluation of Infrasound and Strobe Lights to Elicit Avoidance Behavior in Juvenile Salmon and Char.

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Robert, P.; Neitzel, Duane A.; Amidan, Brett G.


    Experimental tests were conducted using hatchery reared and wild juvenile chinook salmon Oncorhynchus tshawytscha, eastern brook trout Salvelinus fontinalis, and rainbow trout O. mykiss to determine specific behavior responses to infrasound (<20 Hz) and flashing strobe lights. Caged fish were acclimated in a static test tank and their behavior was recorded using low light cameras. Species specific behavior was characterized by measuring movements of the fish within the cage as well as observing startle and habituation responses. Wild chinook salmon (40-45 mm) and hatchery reared chinook salmon (45-50mm) exhibited avoidance responses when initially exposed to a 10 Hz volume displacement source. Rainbow and eastern brook trout (25-100 mm) did not respond with avoidance or other behaviors to infrasound. Habituation to the infrasound source was evident for chinook salmon during repeated exposures. Wild and hatchery chinook displayed a higher proportion of movement during the initial exposures to infrasound when the acclimation period in the test tank was 2-3 h as compared to a 12-15 h acclimation period. A flashing strobe light produced higher and more consistent movement rates in wild chinook (60% of the tests); hatchery reared chinook salmon (50%) and rainbow trout (80%). No measurable movement or other responses was observed for eastern brook trout. Little if any habituation was observed during repeated exposures to strobe lights. Results from this study indicate that consistent repeatable responses can be elicited from some fish using high intensity strobe lights under a controlled laboratory testing. The specific behaviors observed in these experiments might be used to predict how fish might react to low frequency sound and strobe lights in a screening facility. Because sub-yearling salmonids and resident species are susceptible from becoming entrained at water diversion structures we conducted tests in conjunction with our evaluation of juvenile fish screening

  1. Impact of Forest Harvesting on Trophic Structure of Eastern Canadian Boreal Shield Lakes: Insights from Stable Isotope Analyses (United States)

    Glaz, Patricia; Sirois, Pascal; Archambault, Philippe; Nozais, Christian


    Perturbations on ecosystems can have profound immediate effects and can, accordingly, greatly alter the natural community. Land-use such as forestry activities in the Canadian Boreal region have increased in the last decades, raising concerns about their potential impact on aquatic ecosystems. The objective of this study was to evaluate the impact of forest harvesting on trophic structure in eastern Canadian Boreal Shield lakes. We measured carbon and nitrogen stable isotopes values for aquatic primary producers, terrestrial detritus, benthic macroinvertebrates, zooplankton and brook trout (Salvelinus fontinalis) over a three-year period in eight eastern Boreal Shield lakes. Four lakes were studied before, one and two years after forest harvesting (perturbed lakes) and compared with four undisturbed reference lakes (unperturbed lakes) sampled at the same time. Stable isotope mixing models showed leaf-litter to be the main food source for benthic primary consumers in both perturbed and unperturbed lakes, suggesting no logging impact on allochthonous subsidies to the littoral food web. Brook trout derived their food mainly from benthic predatory macroinvertebrates in unperturbed lakes. However, in perturbed lakes one year after harvesting, zooplankton appeared to be the main contributor to brook trout diet. This change in brook trout diet was mitigated two years after harvesting. Size-related diet shift were also observed for brook trout, indicating a diet shift related to size. Our study suggests that carbon from terrestrial habitat may be a significant contribution to the food web of oligotrophic Canadian Boreal Shield lakes. Forest harvesting did not have an impact on the diet of benthic primary consumers. On the other hand, brook trout diet composition was affected by logging with greater zooplankton contribution in perturbed lakes, possibly induced by darker-colored environment in these lakes one year after logging. PMID:24763366

  2. Minimum Pool and Bull Trout Prey Base Investigations at Beulah Reservoir - Final Report for 2008 (United States)

    Rose, Brien P.; Mesa, Matthew G.


    Beulah Reservoir in southeastern Oregon provides irrigation water to nearby farms and supports an adfluvial population of threatened bull trout (Salvelinus confluentus). Summer drawdowns in the reservoir could affect forage fish production and overwintering bull trout. To assess the impacts of drawdown, we sampled fish, invertebrates, and water-quality variables seasonally during 2006-08. In 2006, the summer drawdown was about 68 percent of full pool, which was less than a typical drawdown of 85 percent. We detected few changes in pelagic invertebrate densities, and catch rates, abundance, and sizes of fish when comparing values from spring to values from fall. We did note that densities of benthic insects in areas that were dewatered annually were lower than those from areas that were not dewatered annually. In 2007, the drawdown was 100 percent (to run-of-river level) and resulted in decreases in abundance of invertebrates as much as 96 percent, decreases in catch rates of fish as much as 80 percent, decreases in abundance of redside shiners (Richardsonius balteatus) and northern pikeminnow (Ptychocheilus oregonensis) as much as 93 percent, and decreased numbers of small fish in catches. In the fall 2007, we estimated the total biomass of forage fish to be 76 kilograms, or about one-quarter of total biomass of forage fish in 2006. Bioenergetics modeling suggested that ample forage for about 1,000 bull trout would exist after a moderate drawdown, but that forage remaining after a complete dewatering would not be sufficient for a population one-fifth the size. Our results indicate that drawdowns in Beulah Reservoir affect the aquatic community and perhaps the health and well-being of bull trout. The severity of effects depends on the extent of drawdown, population size of bull trout, and perhaps other factors.

  3. Comparative bioenergetics modeling of two Lake Trout morphotypes (United States)

    Kepler, Megan V.; Wagner, Tyler; Sweka, John A.


    Efforts to restore Lake Trout Salvelinus namaycush in the Laurentian Great Lakes have been hampered for decades by several factors, including overfishing and invasive species (e.g., parasitism by Sea Lampreys Petromyzon marinus and reproductive deficiencies associated with consumption of Alewives Alosa pseudoharengus). Restoration efforts are complicated by the presence of multiple body forms (i.e., morphotypes) of Lake Trout that differ in habitat utilization, prey consumption, lipid storage, and spawning preferences. Bioenergetics models constitute one tool that is used to help inform management and restoration decisions; however, bioenergetic differences among morphotypes have not been evaluated. The goal of this research was to investigate bioenergetic differences between two actively stocked morphotypes: lean and humper Lake Trout. We measured consumption and respiration rates across a wide range of temperatures (4–22°C) and size-classes (5–100 g) to develop bioenergetics models for juvenile Lake Trout. Bayesian estimation was used so that uncertainty could be propagated through final growth predictions. Differences between morphotypes were minimal, but when present, the differences were temperature and weight dependent. Basal respiration did not differ between morphotypes at any temperature or size-class. When growth and consumption differed between morphotypes, the differences were not consistent across the size ranges tested. Management scenarios utilizing the temperatures presently found in the Great Lakes (e.g., predicted growth at an average temperature of 11.7°C and 14.4°C during a 30-d period) demonstrated no difference in growth between the two morphotypes. Due to a lack of consistent differences between lean and humper Lake Trout, we developed a model that combined data from both morphotypes. The combined model yielded results similar to those of the morphotype-specific models, suggesting that accounting for morphotype differences may

  4. Temperature effects induced by climate change on the growth and consumption by salmonines in Lakes Michigan and Huron (United States)

    Kao, Yu-Chun; Madenjian, Charles P.; Bunnell, David B.; Lofgren, Brent M.; Perroud, Marjorie


    We used bioenergetics models to investigate temperature effects induced by climate change on the growth and consumption by Chinook salmon Oncorhynchus tshawytscha, lake trout Salvelinus namaycush, and steelhead O. mykiss in Lakes Michigan and Huron. We updated biological inputs to account for recent changes in the food webs and used temperature inputs in response to regional climate observed in the baseline period (1964–1993) and projected in the future period (2043–2070).Bioenergetics simulations were run across multiple age-classes and across all four seasons in different scenarios of prey availability. Due to the increased capacity of prey consumption, future growth and consumption by these salmonines were projected to increase substantially when prey availability was not limited. When prey consumption remained constant, future growth of these salmonines was projected to decrease in most cases but increase in some cases where the increase in metabolic cost can be compensated by the decrease in waste (egestion and excretion) loss. Consumption by these salmonines was projected to increase the most during spring and fall when prey energy densities are relatively high. Such seasonality benefits their future growth through increasing annual gross energy intake. Our results indicated that lake trout and steelhead would be better adapted to the warming climate than Chinook salmon. To maintain baseline growth into the future, an increase of 10 % in baseline prey consumption was required for Chinook salmon but considerably smaller increases, or no increases, in prey consumption were needed by lake trout and steelhead.

  5. Monitor and Protect Wigwam River Bull Trout for Koocanusa Reservoir : Summary of the Skookumchuck Creek Bull Trout Enumeration Project, Annual Report 2001.

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, James S.; Baxter, Jeremy


    This report summarizes the second year of a bull trout (Salvelinus confluentus) enumeration project on Skookumchuck Creek in southeastern British Columbia. An enumeration fence and traps were installed on the creek from September 6th to October 12th 2001 to enable the capture of post-spawning bull trout emigrating out of the watershed. During the study period, a total of 273 bull trout were sampled through the enumeration fence. Length and weight were determined for all bull trout captured. In total, 39 fish of undetermined sex, 61 males and 173 females were processed through the fence. An additional 19 bull trout were observed on a snorkel survey prior to the fence being removed on October 12th. Coupled with the fence count, the total bull trout enumerated during this project was 292 fish. Several other species of fish were captured at the enumeration fence including westslope cutthroat trout (Oncorhynchus clarki lewisi), Rocky Mountain whitefish (Prosopium williamsoni), and kokanee (O. nerka). A total of 143 bull trout redds were enumerated on the ground in two different locations (river km 27.5-30.5, and km 24.0-25.5) on October 3rd. The majority of redds (n=132) were observed in the 3.0 km index section (river km 27.5-30.5) that has been surveyed over the past five years. The additional 11 redds were observed in a 1.5 km section (river km 24.0-25.5). Summary plots of water temperature for Bradford Creek, Sandown Creek, Buhl Creek, and Skookumchuck Creek at three locations suggested that water temperatures were within the temperature range preferred by bull trout for spawning, egg incubation, and rearing.

  6. Relative abundance, site fidelity, and survival of adult lake trout in Lake Michigan from 1999 to 2001: Implications for future restoration strategies (United States)

    Bronte, C.R.; Holey, M.E.; Madenjian, C.P.; Jonas, J.L.; Claramunt, R.M.; McKee, P.C.; Toneys, M.L.; Ebener, M.P.; Breidert, B.; Fleischer, G.W.; Hess, R.; Martell, A.W.; Olsen, E.J.


    We compared the relative abundance of lake trout Salvelinus namaycush spawners in gill nets during fall 1999–2001 in Lake Michigan at 19 stocked spawning sites with that at 25 unstocked sites to evaluate how effective site-specific stocking was in recolonizing historically important spawning reefs. The abundance of adult fish was higher at stocked onshore and offshore sites than at unstocked sites. This suggests that site-specific stocking is more effective at establishing spawning aggregations than relying on the ability of hatchery-reared lake trout to find spawning reefs, especially those offshore. Spawner densities were generally too low and too young at most sites to expect significant natural reproduction. However, densities were sufficiently high at some sites for reproduction to occur and therefore the lack of recruitment was attributable to other factors. Less than 3% of all spawners could have been wild fish, which indicates that little natural reproduction occurred in past years. Wounding by sea lamprey Petromyzon marinus was generally lower for Seneca Lake strain fish and highest for strains from Lake Superior. Fish captured at offshore sites in southern Lake Michigan had the lowest probability of wounding, while fish at onshore sites in northern Lake Michigan had the highest probability. The relative survival of the Seneca Lake strain was higher than that of the Lewis Lake or the Marquette strains for the older year-classes examined. Survival differences among strains were less evident for younger year-classes. Recaptures of coded-wire-tagged fish of five strains indicated that most fish returned to their stocking site or to a nearby site and that dispersal from stocking sites during spawning was about 100 km. Restoration strategies should rely on site-specific stocking of lake trout strains with good survival at selected historically important offshore spawning sites to increase egg deposition and the probability of natural reproduction in Lake

  7. Sample size requirements and analysis of tag recoveries for paired releases of lake trout (United States)

    Elrod, Joseph H.; Frank, Anthony


    A simple chi-square test can be used to analyze recoveries from a paired-release experiment to determine whether differential survival occurs between two groups of fish. The sample size required for analysis is a function of (1) the proportion of fish stocked, (2) the expected proportion at recovery, (3) the level of significance (a) at which the null hypothesis is tested, and (4) the power (1-I?) of the statistical test. Detection of a 20% change from a stocking ratio of 50:50 requires a sample of 172 (I?=0.10; 1-I?=0.80) to 459 (I?=0.01; 1-I?=0.95) fish. Pooling samples from replicate pairs is sometimes an appropriate way to increase statistical precision without increasing numbers stocked or sampling intensity. Summing over time is appropriate if catchability or survival of the two groups of fish does not change relative to each other through time. Twelve pairs of identical groups of yearling lake trout Salvelinus namaycush were marked with coded wire tags and stocked into Lake Ontario. Recoveries of fish at ages 2-8 showed differences of 1-14% from the initial stocking ratios. Mean tag recovery rates were 0.217%, 0.156%, 0.128%, 0.121%, 0.093%, 0.042%, and 0.016% for ages 2-8, respectively. At these rates, stocking 12,100-29,700 fish per group would yield samples of 172-459 fish at ages 2-8 combined.

  8. Using bioenergetics modeling to estimate consumption of native juvenile salmonids by nonnative northern pike in the Upper Flathead River System, Montana (United States)

    Muhlfeld, C.C.; Bennett, D.H.; Kirk, Steinhorst R.; Marotz, B.; Boyer, M.


    Introductions of nonnative northern pike Esox lucius have created recreational fisheries in many waters in the United States and Canada, yet many studies have shown that introduced northern pike may alter the composition and structure of fish communities through predation. We estimated the abundance of nonnative northern pike (2002-2003) and applied food habits data (1999-2003) to estimate their annual consumption of native bull trout Salvelinus confluentus and westslope cutthroat trout Oncorhynchus clarkii lewisi juveniles in the upper Flathead River system, Montana. Population estimates were generally consistent among years and ranged from 1,200 to 1,300 individuals. Westslope cutthroat trout were present in the diet of younger (???600 mm) and older (>600 mm) northern pike during all seasons and bull trout were found only in larger northern pike during all seasons but summer. Bioenergetics modeling estimated that the northern pike population annually consumed a total of 8.0 metric tons (mt) of fish flesh; the highest biomass was composed of cyprinids (4.95 mt) followed by whitefishes Prosopium spp. (1.02 mt), bull trout (0.80 mt), westslope cutthroat trout (0.68 mt), yellow perch Perca flavescens (0.41 mt),1 and other fishes (centrarchids and cottids; 0.14 mt). Numerically, the northern pike population consumed more than 342,000 fish; cyprinids and catostomids comprised approximately 82% of prey fish (278,925), whereas over 13,000 westslope cutthroat trout and nearly 3,500 bull trout were eaten, comprising about 5% of the prey consumed. Our results suggest that predation by introduced northern pike is contributing to the lower abundance of native salmonids in the system and that a possible benefit might accrue to native salmonids by reducing these predatory interactions. ?? Copyright by the American Fisheries Society 2008.

  9. The effects of varied densities on the growth and emigration of adult cutthroat trout and brook trout in fenced stream enclosures (United States)

    Buys, D.J.; Hilderbrand, R.H.; Kershner, J.L.


    We evaluated the effects of various density treatments on adult fish growth and emigration rates between Bonneville cutthroat trout Oncorhynchus clarki utah and brook trout Salvelinus fontinalis in stream enclosures in Beaver Creek, Idaho, We used 3 density treatments (low, ambient, and high fish densities) to evaluate density-related effects and to ensure a response. Intraspecific ambient-density tests using cutthroat trout only were also performed. Results indicated an absence of cage effects in the stream enclosures and no differences in fish growth between ambient-density stream-enclosure fish and free-range fish. Brook trout outgrew and moved less than cutthroat trout in the stream enclosures, especially as density increased, In all 3 density treatments, brook trout gained more weight than cutthroat trout, with brook trout gaining weight in each density treatment and cutthroat trout losing weight at the highest density. At high densities, cutthroat trout attempted to emigrate more frequently than brook trout in sympatry and allopatry. We observed a negative correlation between growth and emigration for interspecific cutthroat trout, indicating a possible competitive response due to the presence of brook trout. We observed similar responses for weight and emigration in trials of allopatric cutthroat trout, indicating strong intraspecific effects as density increased. While cutthroat trout showed a response to experimental manipulation with brook trout at different densities, there has been long-term coexistence between these species in Beaver Creek, This system presents a unique opportunity to study the mechanisms that lead cutthroat trout to coexist with rather than be replaced by nonnative brook trout.

  10. Lipid and moisture content modeling of amphidromous Dolly Varden using bioelectrical impedance analysis (United States)

    Stolarski, J.T.; Margraf, F.J.; Carlson, J.G.; Sutton, T.M.


    The physiological well-being or condition of fish is most commonly estimated from aspects of individual morphology. However, these metrics may be only weakly correlated with nutritional reserves stored as lipid, the primary form of accumulated energy in fish. We constructed and evaluated bioelectrical impedance analysis (BIA) models as an alternative method of assessing condition in amphidromous Dolly Varden Salvelinus malma collected from nearshore estuarine and lotic habitats of the Alaskan Arctic. Data on electrical resistance and reactance were collected from the lateral and ventral surfaces of 192 fish, and whole-body percent lipid and moisture content were determined using standard laboratory methods. Significant inverse relationships between temperature and resistance and reactance prompted the standardization of these data to a constant temperature using corrective equations developed herein. No significant differences in resistance or reactance were detected among spawning and nonspawning females after accounting for covariates, suggesting that electrical pathways do not intersect the gonads. Best-fit BIA models incorporating electrical variables calculated from the lateral and ventral surfaces produced the strongest associations between observed and model-predicted estimates of proximate content. These models explained between 6% and 20% more of the variability in laboratory-derived estimates of proximate content than models developed from single-surface BIA data and 32% more than models containing only length and weight data. While additional research is required to address the potential effects of methodological variation, bioelectrical impedance analysis shows promise as a way to provide high-quality, minimally invasive estimates of Dolly Varden lipid or moisture content in the field with only small increases in handling time.

  11. Phenotype flexibility in wild fish: Dolly Varden regulate assimilative capacity to capitalize on annual pulsed subsidies. (United States)

    Armstrong, Jonathan B; Bond, Morgan H


    1. Large digestive organs increase rates of energy gain when food is plentiful but are costly to maintain and increase rates of energy loss when food is scarce. The physiological adaptations to this trade-off differ depending on the scale and predictability of variation in food abundance. 2. Currently, there is little understanding of how animals balance trade-offs between the cost and capacity of the digestive system in response to resource pulses: rare, ephemeral periods of resource superabundance. We investigated the physiological and behavioural tactics of the fish Dolly Varden (Salvelinus malma) that rear in watersheds with low in situ productivity, but experience annual resource pulses from the spawning migrations of Pacific salmon. The eggs of Pacific salmon provide high-energy food for Dolly Varden. 3. Dolly Varden sampled 6 weeks prior to the resource pulse exhibited atrophy of the stomach, pyloric caeca, intestine and liver. Throughout the portion of the growing season prior to the resource pulse, fish exhibited empty stomachs, low indices of energy condition and muscle isotope signatures reflecting the previous resource pulse. 4. During the resource pulse, Dolly Varden exhibited large digestive machinery, gorged on salmon eggs and rapidly stored energy in fat reserves, somatic growth and gonad development. Dolly Varden appeared to achieve nearly their entire annual energy surplus during the ∼ 5-week period when sockeye salmon spawn. 5. Digestive flexibility provides Dolly Varden the energy efficiency required to survive and reproduce when resource abundance is concentrated into an annual pulse that is predictable, yet highly ephemeral. Although fish are known to incur extremely variable energy budgets, our study is one of the first to document digestive flexibility in wild fish. Our study emphasizes that fish can rely heavily on rare, high-magnitude foraging opportunities. Human actions that attenuate spikes in food abundance may have stronger than

  12. Total mercury concentrations in anadromous Northern Dolly Varden from the northwestern Canadian Arctic: A historical baseline study

    Energy Technology Data Exchange (ETDEWEB)

    Tran, L., E-mail: [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Reist, J.D. [Fisheries and Oceans Canada, Winnipeg, Manitoba R3T 2N6 (Canada); Power, M., E-mail: [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)


    Previous research has documented the significance of total mercury (THg) as a northern contaminant in general and of fish in particular. While much research has been devoted to documenting both spatial and temporal changes in THg in consumed fish, little effort has been directed at understanding patterns of THg in Dolly Varden (Salvelinus malma), a prized subsistence species throughout the western North American Arctic. Here we report historical THg concentrations for anadromous Dolly Varden from 10 populations in the Yukon and Northwest Territories sampled across a range of latitudes (67–69°N) and longitudes (136–141°W) between the years 1988–91. Unadjusted mean THg concentrations ranged from 15 to 254 ng/g wet weight. Length-adjusted THg concentrations were significantly different among sites, but were not related to latitude or longitude. Within and among populations, THg was significantly related to fork-length, age, δ{sup 15}N, and δ{sup 13}C, with the variation in THg found among populations being best explained by size. The data serve as an important baseline against which future changes in THg levels in this important subsistence fishery may be compared to determine the significance of any observed trends. - Highlights: • THg were measured in Dolly Varden from the Yukon and Northwest Territories. • Length-adjusted THg concentrations were not related to latitude or longitude. • Among-population variation in THg was best explained by fork-length. • Length-adjusted THg concentrations were related to age, δ{sup 15}N, and δ{sup 13}C. • Mean THg were below Health Canada’s consumption guideline for commercial fish.

  13. Stock origins of Dolly Varden collected from Beaufort Sea coastal sites of Arctic Alaska and Canada (United States)

    Krueger, C.C.; Wilmot, R.L.; Everett, R.J.


    Anadromous northern Dolly Varden Salvelinus malma support a summer subsistence fishery in Beaufort Sea coastal waters. These same waters coincide with areas of oil and gas exploration and development. The purpose of this study was to assess variation in stock origins of Dolly Varden collected from sites along 400 km of Beaufort Sea coast. Mixed-stock analyses (MSA) of allozyme data were used to compare collections from four sites (Endicolt near Prudhoe Bay, Mikkelsen Bay, and Kaktovik in Alaska and Phillips Bay in Canada) and to assess variation in stock contributions among summer months and between 1987 and 1988. The MSA estimates for individual stocks were summed into estimates for three stock groups: western stocks from the area near Sagavarnirktok River and Prudhoe Bay (SAG), Arctic National Wildlife Refuge stocks (Arctic Refuge), and Canadian stocks. The MSA of Endicott samples taken in 1987 and 1988 did not differ among months in terms of contributions from local SAG stocks (range, 71-95%). Contributions from nonlocal (>100 km distant) Canadian and Arctic Refuge stocks were not different from zero in 1987, but contributions from Canadian stocks were so in July (17%) and August (20%) but not in September of 1988. Thus, stock contributions to Endicott collections were different between 1987 and 1988. Samples from the Kaktovik area in 1988 were different between months in terms of contributions from nonlocal SAG stocks (July, 7%; August, 27%). Significant contributions to these samples were made both months by Canadian (25% and 17%) and local Arctic Refuge stocks (68% and 56%). Among the four coastal sites, local stocks typically contributed most to collections; however, every site had collections that contained significant contributions from nonlocal stocks. The MSA estimates clearly revealed the movement of Dolly Varden between U.S. and Canada coastal waters. If local stocks are affected by oil and gas development activities, distant subsistence fisheries

  14. Evaluation of the Life History of Native Salmonids in the Malheur River Basin; Cooperative Bull Trout/Redband Trout Research Project, 1999-2000 Annual Report.

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    Schwabe, Lawrence; Tiley, Mark (Burns Paiute Tribe, Department of Fish and Wildlife, Burns, OR); Perkins, Raymond R. (Oregon Department of Fish and Wildlife, Ontario, OR)


    The purpose of this study is to document the seasonal distribution of adult/sub-adult bull trout (Salvelinus confluentus) in the Malheur River basin. Due to the decline of bull trout in the Columbia Basin, the United States Fish and Wildlife Service listed bull trout as a threatened species in June 1998. Past land management activities; construction of dams; and fish eradication projects in the North Fork and Middle Fork Malheur River by poisoning have worked in concert to cumulatively impact native species in the Malheur Basin (Bowers et. al. 1993). Survival of the remaining bull trout populations is severely threatened (Buchanan 1997). 1999 Research Objects are: (1) Document the migratory patterns of adult/sub-adult bull trout in the North Fork Malheur River; (2) Determine the seasonal bull trout use of Beulah Reservoir and bull trout entrainment; and (3) Timing and location of bull trout spawning in the North Fork Malheur River basin. The study area includes the Malheur basin from the mouth of the Malheur River located near Ontario, Oregon to the headwaters of the North Fork Malheur River (Map 1). All fish collected and most of the telemetry effort was done on the North Fork Malheur River subbasin (Map 2). Fish collection was conducted on the North Fork Malheur River at the tailwaters of Beulah Reservoir (RK 29), Beulah Reservoir (RK 29-RK 33), and in the North Fork Malheur River at Crane Crossing (RK 69) to the headwaters of the North Fork Malheur. Radio telemetry was done from the mouth of the Malheur River in Ontario, Oregon to the headwaters of the North Fork Malheur. This report will reflect all migration data collected from 3/1/99 to 12/31/99.

  15. Accounting for groundwater in stream fish thermal habitat responses to climate change. (United States)

    Snyder, Craig D; Hitt, Nathaniel P; Young, John A


    Forecasting climate change effects on aquatic fauna and their habitat requires an understanding of how water temperature responds to changing air temperature (i.e., thermal sensitivity). Previous efforts to forecast climate effects on brook trout (Salvelinus fontinalis) habitat have generally assumed uniform air-water temperature relationships over large areas that cannot account for groundwater inputs and other processes that operate at finer spatial scales. We developed regression models that accounted for groundwater influences on thermal sensitivity from measured air-water temperature relationships within forested watersheds in eastern North America (Shenandoah National Park, Virginia, USA, 78 sites in nine watersheds). We used these reach-scale models to forecast climate change effects on stream temperature and brook trout thermal habitat, and compared our results to previous forecasts based upon large-scale models. Observed stream temperatures were generally less sensitive to air temperature than previously assumed, and we attribute this to the moderating effect of shallow groundwater inputs. Predicted groundwater temperatures from air-water regression models corresponded well to observed groundwater temperatures elsewhere in the study area. Predictions of brook trout future habitat loss derived from our fine-grained models. were far less pessimistic than those from prior models developed at coarser spatial resolutions. However, our models also revealed spatial variation in thermal sensitivity within and among catchments resulting in a patchy distribution of thermally suitable habitat. Habitat fragmentation due to thermal barriers therefore may have an increasingly important role for trout population viability in headwater streams. Our results demonstrate that simple adjustments to air-water temperature regression models can provide a powerful and cost-effective approach for predicting future stream temperatures while accounting for effects of groundwater.

  16. Robust detection of rare species using environmental DNA: the importance of primer specificity.

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    Taylor M Wilcox

    Full Text Available Environmental DNA (eDNA is being rapidly adopted as a tool to detect rare animals. Quantitative PCR (qPCR using probe-based chemistries may represent a particularly powerful tool because of the method's sensitivity, specificity, and potential to quantify target DNA. However, there has been little work understanding the performance of these assays in the presence of closely related, sympatric taxa. If related species cause any cross-amplification or interference, false positives and negatives may be generated. These errors can be disastrous if false positives lead to overestimate the abundance of an endangered species or if false negatives prevent detection of an invasive species. In this study we test factors that influence the specificity and sensitivity of TaqMan MGB assays using co-occurring, closely related brook trout (Salvelinus fontinalis and bull trout (S. confluentus as a case study. We found qPCR to be substantially more sensitive than traditional PCR, with a high probability of detection at concentrations as low as 0.5 target copies/µl. We also found that number and placement of base pair mismatches between the Taqman MGB assay and non-target templates was important to target specificity, and that specificity was most influenced by base pair mismatches in the primers, rather than in the probe. We found that insufficient specificity can result in both false positive and false negative results, particularly in the presence of abundant related species. Our results highlight the utility of qPCR as a highly sensitive eDNA tool, and underscore the importance of careful assay design.

  17. Ecological factors affecting Rainbow Smelt recruitment in the main basin of Lake Huron, 1976-2010 (United States)

    O'Brien, Timothy P.; Taylor, William W.; Roseman, Edward F.; Madenjian, Charles P.; Riley, Stephen C.


    Rainbow Smelt Osmerus mordax are native to northeastern Atlantic and Pacific–Arctic drainages and have been widely introduced throughout North America. In the Great Lakes region, Rainbow Smelt are known predators and competitors of native fish and a primary prey species in pelagic food webs. Despite their widespread distribution, importance as a prey species, and potential to negatively interact with native fish species, there is limited information concerning stock–recruitment relationships for Rainbow Smelt. To better understand recruitment mechanisms, we evaluated potential ecological factors determining recruitment dynamics for Rainbow Smelt in Lake Huron using data from bottom trawl catches. We specifically evaluated influence of stock size, environmental factors (water temperature, lake levels, and precipitation), and salmonine predation on the production of age-0 recruits from 1976 to 2010. Rainbow Smelt recruitment was negatively related to stock size exceeding 10 kg/ha, indicating that compensatory, density-dependent mortality from cannibalism or intraspecific competition was an important factor related to the production of age-0 recruits. Recruitment was positively related to spring precipitation suggesting that the amount of stream-spawning habitat as determined by precipitation was important for the production of strong Rainbow Smelt recruitment. Additionally, density of age-0 Rainbow Smelt was positively related to Lake Trout Salvelinus namaycush abundance. However, spawning stock biomass of Rainbow Smelt, which declined substantially from 1989 to 2010, was negatively associated with Lake Trout catch per effort suggesting predation was an important factor related to the decline of age-2 and older Rainbow Smelt in Lake Huron. As such, we found that recruitment of Rainbow Smelt in Lake Huron was regulated by competition with or cannibalism by older conspecifics, spring precipitation influencing stream spawning habitats, and predation by Lake Trout on

  18. Kootenai River Fisheries Investigations; Rainbow and Bull Trout Recruitment, 1999 Annual Report.

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    Walters, Jody P.; Downs, Christopher C.


    Our 1999 objectives were to determine sources of rainbow trout Oncorhynchus mykiss and bull trout Salvelinus confluentus spawning and recruitment in the Idaho reach of the Kootenai River. We used a rotary-screw trap to capture juvenile trout to determine age at out-migration and to estimate total out-migration from the Boundary Creek drainage to the Kootenai River. The out-migrant estimate for March through August 1999 was 1,574 (95% C. I. = 825-3,283) juvenile rainbow trout. Most juveniles out-migrated at age-2 and age-3. No out-migrating bull trout were caught. Five of 17 rainbow trout radio-tagged in Idaho migrated upstream into Montana waters during the spawning season. Five bull trout originally radio-tagged in O'Brien Creek, Montana in early October moved downstream into Idaho and British Columbia by mid-October. Annual angler exploitation for the rainbow trout population upstream of Bonners Ferry, Idaho was estimated to be 58%. Multi-pass depletion estimates for index reaches of Caboose, Curley, and Debt creeks showed 0.20, 0.01, and 0.13 rainbow trout juveniles/m{sup 2}, respectively. We estimated rainbow trout (180-415 mm TL) standing stock of 1.6 kg/ha for the Hemlock Bar reach (29.4 ha) of the Kootenai River, similar to the 1998 estimate. Recruitment of juvenile rainbow and bull trout from Idaho tributaries is not sufficient to be the sole source of subsequent older fish in the mainstem Kootenai River. These populations are at least partly dependent on recruitment from Montana waters. The low recruitment and high exploitation rate may be indicators of a rainbow trout population in danger of further decline.

  19. Feeding ecology of native and nonnative salmonids during the expansion of a nonnative apex predator in Yellowstone Lake, Yellowstone National Park (United States)

    Syslo, John M.; Guy, Christopher S.; Koel, Todd M.


    The illegal introduction of Lake Trout Salvelinus namaycush into Yellowstone Lake, Yellowstone National Park, preceded the collapse of the native population of Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri, producing a four-level trophic cascade. The Yellowstone Cutthroat Trout population’s collapse and the coinciding increase in Lake Trout abundance provided a rare opportunity to evaluate the feeding ecology of a native prey species and a nonnative piscivore species after the restructuring of a large lentic ecosystem. We assessed diets, stable isotope signatures, and depth-related CPUE patterns for Yellowstone Cutthroat Trout and Lake Trout during 2011–2013 to evaluate trophic overlap. To evaluate diet shifts related to density, we also compared 2011–2013 diets to those from studies conducted during previous periods with contrasting Yellowstone Cutthroat Trout and Lake Trout CPUEs. We illustrate the complex interactions between predator and prey in a simple assemblage and demonstrate how a nonnative apex predator can alter competitive interactions. The diets of Yellowstone Cutthroat Trout were dominated by zooplankton during a period when the Yellowstone Cutthroat Trout CPUE was high and were dominated by amphipods when the CPUE was reduced. Lake Trout shifted from a diet that was dominated by Yellowstone Cutthroat Trout during the early stages of the invasion to a diet that was dominated by amphipods after Lake Trout abundance had increased and after Yellowstone Cutthroat Trout prey had declined. The shifts in Yellowstone Cutthroat Trout and Lake Trout diets resulted in increased trophic similarity of these species through time due to their shared reliance on benthic amphipods. Yellowstone Cutthroat Trout not only face the threat posed by Lake Trout predation but also face the potential threat of competition with Lake Trout if amphipods are limiting. Our results demonstrate the importance of studying the long-term feeding ecology of fishes in

  20. Impact of thiamine deficiency on T-cell dependent and T-cell independent antibody production in lake trout. (United States)

    Ottinger, Christopher A; Honeyfield, Dale C; Densmore, Christine L; Iwanowicz, Luke R


    Lake trout Salvelinus namaycush on thiamine-replete and thiamine-depleted diets were evaluated for the effects of thiamine status on in vivo responses to the T-dependent antigen trinitophenol (TNP)-keyhole limpet hemocyanin (TNP-KLH), the T-independent antigen trinitrophenol-lipolysaccaharide (TNP-LPS), or Dulbecco's phosphate-buffered saline (DPBS; negative control fish). Plasma antibody concentrations were evaluated for possible differences in total anti-TNP activity as well as differences in response kinetics. Associations between anti-TNP activity and muscle and liver thiamine concentrations as well as ratios of muscle-to-liver thiamine to anti-TNP activity were also examined. Thiamine-depleted lake trout that were injected with TNP-LPS exhibited significantly more anti-TNP activity than thiamine-replete fish. The depleted fish injected with TNP-LPS also exhibited significantly different response kinetics relative to thiamine-replete lake trout. No differences in activity or kinetics were observed between the thiamine-replete and -depleted fish injected with TNP-KLH or in the DPBS negative controls. Anti-TNP activity in thiamine-depleted lake trout injected with TNP-KLH was positively associated with muscle thiamine pyrophosphate (thiamine diphosphate; TPP) concentration. A negative association was observed between the ratio of muscle-to-liver TPP and T-independent responses. No significant associations between anti-TNP activity and tissue thiamine concentration were observed in the thiamine-replete fish. We demonstrated that thiamine deficiency leads to alterations in both T-dependent and T-independent immune responses in lake trout.

  1. Changes in seasonal climate outpace compensatory density-dependence in eastern brook trout (United States)

    Bassar, Ronald D.; Letcher, Benjamin H.; Nislow, Keith H.; Whiteley, Andrew R.


    Understanding how multiple extrinsic (density-independent) factors and intrinsic (density-dependent) mechanisms influence population dynamics has become increasingly urgent in the face of rapidly changing climates. It is particularly unclear how multiple extrinsic factors with contrasting effects among seasons are related to declines in population numbers and changes in mean body size and whether there is a strong role for density-dependence. The primary goal of this study was to identify the roles of seasonal variation in climate driven environmental direct effects (mean stream flow and temperature) versus density-dependence on population size and mean body size in eastern brook trout (Salvelinus fontinalis). We use data from a 10-year capture-mark-recapture study of eastern brook trout in four streams in Western Massachusetts, USA to parameterize a discrete-time population projection model. The model integrates matrix modeling techniques used to characterize discrete population structures (age, habitat type and season) with integral projection models (IPMs) that characterize demographic rates as continuous functions of organismal traits (in this case body size). Using both stochastic and deterministic analyses we show that decreases in population size are due to changes in stream flow and temperature and that these changes are larger than what can be compensated for through density-dependent responses. We also show that the declines are due mostly to increasing mean stream temperatures decreasing the survival of the youngest age class. In contrast, increases in mean body size over the same period are the result of indirect changes in density with a lesser direct role of climate-driven environmental change.

  2. Seasonal Change in Trophic Niche of Adfluvial Arctic Grayling (Thymallus arcticus and Coexisting Fishes in a High-Elevation Lake System.

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    Kyle A Cutting

    Full Text Available Introduction of non-native species is a leading threat to global aquatic biodiversity. Competition between native and non-native species is often influenced by changes in suitable habitat or food availability. We investigated diet breadth and degree of trophic niche overlap for a fish assemblage of native and non-native species inhabiting a shallow, high elevation lake system. This assemblage includes one of the last remaining post-glacial endemic populations of adfluvial Arctic grayling (Thymallus arcticus in the contiguous United States. We examined gut contents and stable isotope values of fish taxa in fall and spring to assess both short- (days and long-term (few months changes in trophic niches. We incorporate these short-term (gut contents data into a secondary isotope analysis using a Bayesian statistical framework to estimate long-term trophic niche. Our data suggest that in this system, Arctic grayling share both a short- and long-term common food base with non-native trout of cutthroat x rainbow hybrid species (Oncorhynchus clarkia bouvieri x Oncorhynchus mykiss and brook trout (Salvelinus fontinalis. In addition, trophic niche overlap among Arctic grayling, hybrid trout, and brook trout appeared to be stronger during spring than fall. In contrast, the native species of Arctic grayling, burbot (Lota lota, and suckers (Catostomus spp. largely consumed different prey items. Our results suggest strong seasonal differences in trophic niche overlap among Arctic grayling and non-native trout, with a potential for greatest competition for food during spring. We suggest that conservation of endemic Arctic grayling in high-elevation lakes will require recognition of the potential for coexisting non-native taxa to impede well-intentioned recovery efforts.

  3. Bull Trout life History, Genetics, Habitat Needs, and Limiting Factors in Central and Northeast Oregon, Annual Report 1995.

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    Hemmingsen, Alan R.; Buchanan, David V.; Howell, Philip J.


    To fulfill one objective of the present study, genetic characteristics of Oregon bull trout will be determined by analysis of mitochondrial and nuclear DNA. During 1995, the authors collected and sampled a total of 1,217 bull trout from 46 streams in the Columbia River Basin. DNA analysis of those samples will be conducted at University of Montana. They primarily sampled juvenile fish near natal areas to increase the likelihood of identifying discrete populations while minimizing risk of injury to large spawners. Fork lengths of all fish sampled ranged from 2.6 to 60.5 cm with a median of 12 cm. Eighty-four percent of all bull trout sampled were less than 19 cm while two percent were larger than 27 cm. Bull trout were collected by several methods, mostly by electrofishing. Eighty-six percent of all bull trout sampled were collected by electrofishing with a programmable waveform electrofisher. They observed injuries caused by electrofishing to 8% of that proportion. Based on preliminary analysis, no waveform combination used appeared less injurious than others. Highest voltages appeared less injurious than some that were lower. Frequency of electrofishing injury was significantly correlated to fork length over the range-from 4 to 26 cm. There were indications for substantial risk for such injury to bull trout larger than 26 cm. Other species found in association with bull trout included chinook salmon Oncorhynchus tshawytscha, mountain whitefish Prosopium williamsoni, rainbow trout Oncorhynchus mykiss, sculpins Cottus spp., cutthroat trout Oncorhynchus clarki, non-native brook trout Salvelinus fontinalis, and tailed frogs Ascaphus truei. Rainbow trout was the species most frequently associated with bull trout. No injury or mortality was observed for any of the associated species captured.

  4. Response of fish assemblages to declining acidic deposition in Adirondack Mountain lakes, 1984-2012 (United States)

    Baldigo, B. P.; Roy, K. M.; Driscoll, C. T.


    Adverse effects of acidic deposition on the chemistry and fish communities were evident in Adirondack Mountain lakes during the 1980s and 1990s. Fish assemblages and water chemistry in 43 Adirondack Long-Term Monitoring (ALTM) lakes were sampled by the Adirondack Lakes Survey Corporation and the New York State Department of Environmental Conservation during three periods (1984-87, 1994-2005, and 2008-12) to document regional impacts and potential biological recovery associated with the 1990 amendments to the 1963 Clean Air Act (CAA). We assessed standardized data from 43 lakes sampled during the three periods to quantify the response of fish-community richness, total fish abundance, and brook trout (Salvelinus fontinalis) abundance to declining acidity that resulted from changes in U.S. air-quality management between 1984 and 2012. During the 28-year period, mean acid neutralizing capacity (ANC) increased significantly from 3 to 30 μeq/L and mean inorganic monomeric Al concentrations decreased significantly from 2.22 to 0.66 μmol/L, yet mean species richness, all species or total catch per net night (CPNN), and brook trout CPNN did not change significantly in the 43 lakes. Regression analyses indicate that fishery metrics were not directly related to the degree of chemical recovery and that brook trout CPNN may actually have declined with increasing ANC. While the richness of fish communities increased with increasing ANC as anticipated in several Adirondack lakes, observed improvements in water quality associated with the CAA have generally failed to produce detectable shifts in fish assemblages within a large number of ALTM lakes. Additional time may simply be needed for biological recovery to progress, or else more proactive efforts may be necessary to restore natural fish assemblages in Adirondack lakes in which water chemistry is steadily recovering from acidification.

  5. Impacts of climatic variation on trout: A global synthesis and path forward (United States)

    Kovach, Ryan; Muhlfeld, Clint C.; Al-Chokhachy, Robert K.; Dunham, Jason; Letcher, Benjamin; Kershner, Jeffrey L.


    Despite increasing concern that climate change may negatively impact trout—a globally distributed group of fish with major economic, ecological, and cultural value—a synthetic assessment of empirical data quantifying relationships between climatic variation and trout ecology does not exist. We conducted a systematic review to describe how temporal variation in temperature and streamflow influences trout ecology in freshwater ecosystems. Few studies (n = 42) have quantified relationships between temperature or streamflow and trout demography, growth, or phenology, and nearly all estimates (96 %) were for Salvelinus fontinalis and Salmo trutta. Only seven studies used temporal data to quantify climate-driven changes in trout ecology. Results from these studies were beset with limitations that prohibited quantitatively rigorous meta-analysis, a concerning inadequacy given major investment in trout conservation and management worldwide. Nevertheless, consistent patterns emerged from our synthesis, particularly a positive effect of summer streamflow on trout demography and growth; 64 % of estimates were positive and significant across studies, age classes, species, and locations, highlighting that climate-induced changes in hydrology may have numerous consequences for trout. To a lesser degree, summer and fall temperatures were negatively related to population demography (51 and 53 % of estimates, respectively), but temperature was rarely related to growth. To address limitations and uncertainties, we recommend: (1) systematically improving data collection, description, and sharing; (2) appropriately integrating climate impacts with other intrinsic and extrinsic drivers over the entire lifecycle; (3) describing indirect consequences of climate change; and (4) acknowledging and describing intrinsic resiliency.

  6. Walla Walla River Fish Passage Operations Program, 2004-2005 Annual Report.

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    Bronson, James P. (Confederated Tribes of the Umatilla Indian Reservation, Department of Natural Resources, Pendleton, OR); Duke, Bill B. (Oregon Department of Fish and Wildlife, Pendleton, OR)


    In the late 1990s, the Confederated Tribes of the Umatilla Indian Reservation, Oregon Department of Fish and Wildlife, and Washington Department of Fish and Wildlife, along with many other agencies, began implementing fisheries restoration activities in the Walla Walla Basin. An integral part of these efforts is to alleviate the inadequate fish migration conditions in the basin. The migration concerns are being addressed by removing diversion structures, constructing fish passage facilities, implementing minimum instream flow requirements, and providing trap and haul efforts when needed. The objective of the Walla Walla River Fish Passage Operations Project is to increase the survival of migrating adult and juvenile salmonids in the Walla Walla River basin. The project is responsible for coordinating operation and maintenance of ladders, screen sites, bypasses, trap facilities, and transportation equipment. In addition, the project provides technical input on passage criteria and passage and trapping facility design and operation. Operation of the various passage facilities and passage criteria guidelines are outlined in an annual operations plan that the project develops. During the 2004-2005 project year, there were 590 adult summer steelhead, 31 summer steelhead kelts (Oncorhynchus mykiss), 70 adult bull trout (Salvelinus confluentus); 80 adult and 1 jack spring Chinook (O. tshawytscha) enumerated at the Nursery Bridge Dam fishway video counting window between December 13, 2004, and June 16, 2005. Summer steelhead and spring chinook were observed moving upstream while bull trout were observed moving both upstream and downstream of the facility. In addition, the old ladder trap was operated by ODFW in order to enumerate fish passage. Of the total, 143 adult summer steelhead and 15 summer steelhead kelts were enumerated at the west ladder at Nursery Bridge Dam during the video efforts between February 4 and May 23, 2005. Operation of the Little Walla Walla River

  7. 鸭绿江花羔红点鲑、细鳞鱼和长白哲罗鱼的繁殖策略比较研究%The Comparative Studies on the Reproductive Strategies of S.malma,B.lenok and H.iskiawai in Yalu River

    Institute of Scientific and Technical Information of China (English)

    黄权; 周景祥; 刘春力; 陈勇


    应用生态学方法对鸭绿江花羔红点鲑Salvelinus malma (Wabaum)、细鳞鱼Brachymystax lenok (Pallas)和长白哲罗鱼Hcho ishiawai Mori的繁殖策略进行了研究。结果表明:3 种鱼的繁殖策略表现在初次性成熟年龄和规格、繁殖季节、产卵式型和个体绝对繁殖力方面各不相同,而产卵场及其条件和繁殖方式及行为大致相同,是其自身固有物种特性在同一水域适应生态环境的具体表现,充分发挥了不同鱼类利用同一水域空间、时间和饵料生物的潜力。%The reproductive strategies of S.matma,B.lenok and H.iskiawai in Yalu River were studied by means of biology methods. The result showed that the reproductive strategies including ages and size at sex mature,reproductive season,spawing types and absolute fecundity are different while that spawing ground coiditions, way of reproduction and action are similar.It is showed that special features of different fishes were evoluted to adapt to the ecological environment in the same water body, thus bring into full use of the potentiality of space, season and food organisms of water body in Yalu River by different fishes at the same time.

  8. Spatial structure of morphological and neutral genetic variation in Brook Trout (United States)

    Kazyak, David C.; Hilderbrand, Robert H.; Keller, Stephen R.; Colaw, Mark C.; Holloway, Amanda E.; Morgan, Raymond P.; King, Timothy L.


    Brook Trout Salvelinus fontinalis exhibit exceptional levels of life history variation, remarkable genetic variability, and fine-scale population structure. In many cases, neighboring populations may be highly differentiated from one another to an extent that is comparable with species-level distinctions in other taxa. Although genetic samples have been collected from hundreds of populations and tens of thousands of individuals, little is known about whether differentiation at neutral markers reflects phenotypic differences among Brook Trout populations. We compared differentiation in morphology and neutral molecular markers among populations from four geographically proximate locations (all within 24 km) to examine how genetic diversity covaries with morphology. We found significant differences among and/or within streams for all three morphological axes examined and identified the source stream of many individuals based on morphology (52.3% classification efficiency). Although molecular and morphological differentiation among streams ranged considerably (mean pairwise FST: 0.023–0.264; pairwise PST: 0.000–0.339), the two measures were not significantly correlated. While in some cases morphological characters appear to have diverged to a greater extent than expected by neutral genetic drift, many traits were conserved to a greater extent than were neutral genetic markers. Thus, while Brook Trout exhibit fine-scale spatial patterns in both morphology and neutral genetic diversity, these types of biological variabilities are being structured by different ecological and evolutionary processes. The relative influences of genetic drift versus selection and phenotypic plasticity in shaping morphology appear to vary among populations occupying nearby streams.

  9. Climate change expands the spatial extent and duration of preferred thermal habitat for lake Superior fishes.

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    Timothy J Cline

    Full Text Available Climate change is expected to alter species distributions and habitat suitability across the globe. Understanding these shifting distributions is critical for adaptive resource management. The role of temperature in fish habitat and energetics is well established and can be used to evaluate climate change effects on habitat distributions and food web interactions. Lake Superior water temperatures are rising rapidly in response to climate change and this is likely influencing species distributions and interactions. We use a three-dimensional hydrodynamic model that captures temperature changes in Lake Superior over the last 3 decades to investigate shifts in habitat size and duration of preferred temperatures for four different fishes. We evaluated habitat changes in two native lake trout (Salvelinus namaycush ecotypes, siscowet and lean lake trout, Chinook salmon (Oncorhynchus tshawytscha, and walleye (Sander vitreus. Between 1979 and 2006, days with available preferred thermal habitat increased at a mean rate of 6, 7, and 5 days per decade for lean lake trout, Chinook salmon, and walleye, respectively. Siscowet lake trout lost 3 days per decade. Consequently, preferred habitat spatial extents increased at a rate of 579, 495 and 419 km(2 per year for the lean lake trout, Chinook salmon, and walleye while siscowet lost 161 km(2 per year during the modeled period. Habitat increases could lead to increased growth and production for three of the four fishes. Consequently, greater habitat overlap may intensify interguild competition and food web interactions. Loss of cold-water habitat for siscowet, having the coldest thermal preference, could forecast potential changes from continued warming. Additionally, continued warming may render more suitable conditions for some invasive species.

  10. Developing recreational harvest regulations for an unexploited lake trout population (United States)

    Lenker, Melissa A; Weidel, Brian C.; Jensen, Olaf P.; Solomon, Christopher T.


    Developing fishing regulations for previously unexploited populations presents numerous challenges, many of which stem from a scarcity of baseline information about abundance, population productivity, and expected angling pressure. We used simulation models to test the effect of six management strategies (catch and release; trophy, minimum, and maximum length limits; and protected and exploited slot length limits) on an unexploited population of Lake Trout Salvelinus namaycush in Follensby Pond, a 393-ha lake located in New York State’s Adirondack Park. We combined field and literature data and mark–recapture abundance estimates to parameterize an age-structured population model and used the model to assess the effects of each management strategy on abundance, catch per unit effort (CPUE), and harvest over a range of angler effort (0–2,000 angler-days/year). Lake Trout density (3.5 fish/ha for fish ≥ age 13, the estimated age at maturity) was similar to densities observed in other unexploited systems, but growth rate was relatively slow. Maximum harvest occurred at levels of effort ≤ 1,000 angler-days/year in all the scenarios considered. Regulations that permitted harvest of large postmaturation fish, such as New York’s standard Lake Trout minimum size limit or a trophy size limit, resulted in low harvest and high angler CPUE. Regulations that permitted harvest of small and sometimes immature fish, such as a protected slot or maximum size limit, allowed high harvest but resulted in low angler CPUE and produced rapid declines in harvest with increases in effort beyond the effort consistent with maximum yield. Management agencies can use these results to match regulations to management goals and to assess the risks of different management options for unexploited Lake Trout populations and other fish species with similar life history traits.

  11. Frequency and Severity of Trauma in Fishes Subjected to Multiple-pass Depletion Electrofishing (United States)

    Panek, Frank; Densmore, Christine L.


    The incidence and severity of trauma associated with multiple-pass electrofishing and the effects on short-term (30-d) survival and growth of Rainbow Trout Oncorhynchus mykiss, Brook Trout Salvelinus fontinalis, and five representative co-inhabiting nontarget or bycatch species were examined. Fish were held in four rectangular fiberglass tanks (190 × 66 cm) equipped with electrodes, a gravel–cobble stream substrate, and continuous water flow. Fish were exposed to one, two, or three electroshocks (100-V, 60-Hz pulsed DC) spaced 1 h apart or were held as a control. The heterogeneous field produced a mean (±SD) voltage gradient of 0.23 ± 0.024 V/cm (range = 0.20–0.30 V/cm) with a duty cycle of 30% and a 5-s exposure. Radiographs of 355 fish were examined for evidence of spinal injuries, and necropsies were performed on 303 fish to assess hemorrhagic trauma in soft tissue. Using linear regression, we demonstrated significant relationships between the number of electrical shocks and the frequency and severity of hemorrhagic and spinal trauma in each of the nontarget species (Potomac Sculpin Cottus girardi, Channel Catfish Ictalurus punctatus, Fathead Minnow Pimephales promelas, Green Sunfish Lepomis cyanellus, and Largemouth Bass Micropterus salmoides). Most of the injuries in these species were either minor or moderate. Rainbow Trout and Brook Trout generally sustained the highest incidence and severity of injuries, but those injuries were generally independent of the number of treatments. The 30-d postshock survival for the trout species was greater than 94%; survival for the bycatch species ranged from 80% (Fathead Minnow) to 100% (Green Sunfish and Channel Catfish). There were no significant differences in 30-d postshock condition factors despite observations of altered feeding behavior lasting several days to 1 week posttreatment in several of the study species.

  12. A framework for assessing the feasibility of native fish conservation translocations: Applications to threatened bull trout (United States)

    Galloway, Benjamin T.; Muhlfeld, Clint C.; Guy, Christopher S.; Downs, Christopher C.; Fredenberg, Wade A.


    There is an urgent need to consider more aggressive and direct interventions for the conservation of freshwater fishes that are threatened by invasive species, habitat loss, and climate change. Conservation introduction (moving a species outside its indigenous range to other areas where conditions are predicted to be more suitable) is one type of translocation strategy that fisheries managers can use to establish new conservation populations in areas of refugia. To date, however, there are few examples of successful conservation-based introductions. Many attempts fail to establish new populations—in part because environmental factors that might influence success are inadequately evaluated before the translocation is implemented. We developed a framework to assess the feasibility of rescuing threatened fish populations through translocation into historically unoccupied stream and lake habitats. The suitability of potential introduction sites was evaluated based on four major components: the recipient habitat, recipient community, donor population, and future threats. Specific questions were then developed to evaluate each major component. The final assessment was based on a scoring system that addressed each question by using criteria developed from characteristics representative of highly suitable habitats and populations. This framework was used to evaluate the proposed within-drainage translocation of three Bull Trout Salvelinus confluentus populations in Glacier National Park, Montana. Our results indicated that within-drainage translocation is a feasible strategy for conserving locally adapted populations of Bull Trout through the creation of new areas of refugia in Glacier National Park. The framework provides a flexible platform that can help managers make informed decisions for moving threatened fishes into new areas of refugia for conservation and recovery programs.

  13. A Quantitative Polymerase Chain Reaction Assay for the Detection and Quantification of Epizootic Epitheliotropic Disease Virus (EEDV; Salmonid Herpesvirus 3). (United States)

    Glenney, Gavin W; Barbash, Patricia A; Coll, John A


    Epizootic epitheliotropic disease virus (EEDV; salmonid herpesvirus [SalHV3]; family Alloherpesviridae) causes a systemic disease of juvenile and yearling Lake Trout Salvelinus namaycush. No cell lines are currently available for the culture and propagation of EEDV, so primary diagnosis is limited to PCR and electron microscopy. To better understand the pervasiveness of EEDV (carrier or latent state of infection) in domesticated and wild Lake Trout populations, we developed a sensitive TaqMan quantitative PCR (qPCR) assay to detect the presence of the EEDV terminase gene in Lake Trout tissues. This assay was able to detect a linear standard curve over nine logs of plasmid dilution and was sensitive enough to detect single-digit copies of EEDV. The efficiency of the PCR assay was 99.4 ± 0.06% (mean ± SD), with a 95% confidence limit of 0.0296 (R(2) = 0.994). Methods were successfully applied to collect preliminary data from a number of species and water bodies in the states of Pennsylvania, New York, and Vermont, indicating that EEDV is more common in wild fish than previously known. In addition, through the development of this qPCR assay, we detected EEDV in a new salmonid species, the Cisco Coregonus artedi. The qPCR assay was unexpectedly able to detect two additional herpesviruses, the Atlantic Salmon papillomatosis virus (ASPV; SalHV4) and the Namaycush herpesvirus (NamHV; SalHV5), which both share high sequence identity with the EEDV terminase gene. With these unexpected findings, we subsequently designed three primer sets to confirm initial TaqMan qPCR assay positives and to differentiate among EEDV, ASPV, and NamHV by detecting the glycoprotein genes via SYBR Green qPCR. Received April 20, 2015; accepted November 10, 2015.

  14. Inhibition of erythrocytes δ-aminolevulinic acid dehydratase (ALAD) activity in fish from waters affected by lead smelters (United States)

    Schmitt, Christopher J.; Caldwell, Colleen A.; Olsen, Bill; Serdar, Dave; Coffey, Mike


    We assessed the effects on fish of lead (Pb) released to streamsby smelters located in Trail, BC (Canada), E. Helena, MT, Herculaneum, MO, and Glover, MO. Fish were collected by electrofishing from sites located downstream of smelters and from reference sites. Blood from each fish was analyzed for δ-aminolevulinic acid dehydratase (ALAD) activity and hemoglobin (Hb), and samples of blood, liver, or carcass were analyzed for Pb, zinc (Zn), or both. Fish collected downstreamof all four smelters sites had elevated Pb concentrations, decreased ALAD activity, or both relative to their respectivereference sites. At E. Helena, fish from the downstream site also had lower Hb concentrations than fish from upstream. Differences among taxa were also apparent. Consistent with previous studies, ALAD activity in catostomids (Pisces: Catostomidae-northern hog sucker,Hypentelium nigricans;river carpsucker, Carpiodes carpio; largescale sucker, Catostomus macrocheilus; and mountain sucker, C. platyrhynchus) seemed more sensitive to Pb-induced ALADinhibition than the salmonids (Pisces: Salmonidae-rainbow trout,Oncorhynchus mykiss; brook trout,Salvelinus fontinalis) or common carp (Cyprinus carpio). Some of these differences may have resulted from differential accumulation of Zn, which was not measured at all sites. We detected noALAD activity in channel catfish (Ictaluruspunctatus) from either site on the Mississippi River at Herculaneum, MO. Our findings confirmed that Pb is releasedto aquatic ecosystems by smelters and accumulated by fish, andwe documented potentially adverse effects of Pb in fish. We recommend that Zn be measured along with Pb when ALAD activityis used as a biomarker and the collection of at least 10 fish ofa species at each site to facilitate statistical analysis.

  15. Bacterial 16S diversity of basal ice, sediment, and the forefront of Svínafellsjökull glacier via isolation chips and classical culturing techniques (United States)

    Toubes-Rodrigo, Mario; Cook, Simon; Elliott, David; Sen, Robin


    following 16S rRNA gene sequencing and phylogenetics. Basal ice communities comprised a mix of soil and glacial bacteria, with higher proportion of ice-related bacteria in dispersed cryofacies (Polaromonas sp, Flavobacterium xinjiangense) and a water (Arthrobacter agilis) and soil-related microorganisms (Pseudomonas sp) in the debris bands, similar to sub-glacial sediment. During debris band formation, microorganisms from bedrock and overridden soils can be entrained into the ice matrix and those which have adapted to icy conditions can proliferate, explaining the higher viable bacterial counts on dispersed ice as well as higher proportions of glacial isolated-related microorganisms. Once the subglacial sediment and basal ice are released from the glacier and as soil age increases, increased representation of soil-related microbiota (Arthrobacter alpinus, Stenotrophomonas rhizophila) were identified. The results in this study suggest cultivable communities shift in two directions: firstly, within the basal ice layer from subglacial sediment, dominated by soil and water communities towards dispersed ice with a high proportion of glacial communities. The other shift occurs when subglacial sediment is released into the forefront, where the composition changes towards a soil-like microbiota with increase in soil age.

  16. Successional change in the Lake Superior fish community: population trends in ciscoes, rainbow smelt, and lake trout, 1958-2008 (United States)

    Gorman, Owen T.


    The Lake Superior fish community underwent massive changes in the second half of the 20th century. Those changes are largely reflected in changes in abundance of the adults of principal prey species, the ciscoes (Coregonus spp.), the invasive rainbow smelt (Osmerus mordax), and the principal predator, lake trout (Salvelinus namaycush). To better understand changes in species abundances, a comprehensive series of gillnet and bottom trawl data collected from 1958 to 2008 were examined. In the late 1950s/early 1960s, smelt abundance was at its maximum, wild lake trout was at its minimum, and an abundance of hatchery lake trout was increasing rapidly. The bloater (Coregonus hoyi) was the prevalent cisco in the lake; abundance was more than 300% greater than the next most abundant cisco, shortjaw cisco (C. zenithicus), followed by kiyi (C. kiyi) and lake cisco (C. artedi). By the mid-1960s, abundance of hatchery lake trout was nearing maximum, smelt abundance was beginning to decline, and abundances of all ciscoes declined, but especially that of shortjaw cisco and kiyi. By the late 1970s, recovery of wild lake trout stocks was well underway and abundances of hatchery lake trout and smelt were declining and the ciscoes were reaching their nadir. During 1980–1990, the fish community underwent a dramatic shift in organization and structure. The rapid increase in abundance of wild lake trout, concurrent with a rapid decline in hatchery lake trout, signaled the impending recovery. Rainbow smelt abundance dropped precipitously and within four years, lake cisco and bloater populations rebounded on the heels of a series of strong recruitment events. Kiyi populations showed signs of recovery by 1989, and shortjaw by 2000, though well below historic maximum abundances. High abundance of adult smelt prior to 1980 appears to be the only factor linked to recruitment failure in the ciscoes. Life history traits of the cisco species were examined to better understand their different

  17. Changing numbers of spawning cutthroat trout in tributary streams of Yellowstone Lake and estimates of grizzly bears visiting streams from DNA (United States)

    Haroldson, M.A.; Gunther, K.A.; Reinhart, D.P.; Podruzny, S.R.; Cegelski, C.; Waits, L.; Wyman, T.C.; Smith, J.


    Spawning Yellowstone cutthroat trout (Oncorhynchus clarki) provide a source of highly digestible energy for grizzly bears (Ursus arctos) that visit tributary streams to Yellowstone Lake during the spring and early summer. During 1985–87, research documented grizzly bears fishing on 61% of the 124 tributary streams to the lake. Using track measurements, it was estimated that a minimum of 44 grizzly bears fished those streams annually. During 1994, non-native lake trout (Salvelinus namaycush) were discovered in Yellowstone Lake. Lake trout are efficient predators and have the potential to reduce the native cutthroat population and negatively impact terrestrial predators that use cutthroat trout as a food resource. In 1997, we began sampling a subset of streams (n = 25) from areas of Yellowstone Lake surveyed during the previous study to determine if changes in spawner numbers or bear use had occurred. Comparisons of peak numbers and duration suggested a considerable decline between study periods in streams in the West Thumb area of the lake. The apparent decline may be due to predation by lake trout. Indices of bear use also declined on West Thumb area streams. We used DNA from hair collected near spawning streams to estimate the minimum number of bears visiting the vicinity of spawning streams. Seventy-four individual bears were identified from 429 hair samples. The annual number of individuals detected ranged from 15 in 1997 to 33 in 2000. Seventy percent of genotypes identified were represented by more than 1 sample, but only 31% of bears were documented more than 1 year of the study. Sixty-two (84%) bears were only documented in 1 segment of the lake, whereas 12 (16%) were found in 2–3 lake segments. Twenty-seven bears were identified from hair collected at multiple streams. One bear was identified on 6 streams in 2 segments of the lake and during 3 years of the study. We used encounter histories derived from DNA and the Jolly-Seber procedure in Program MARK

  18. Toxaphene in Great Lakes biota and air (United States)

    Glassmeyer, Susan Theresa


    Toxaphene is a complex mixture of at least 600 hexa- through decachlorinated bornanes and bornenes, which was used as an insecticide in the United States from the 1950's until 1982, when it was banned. Toxaphene is ubiquitous in the environment, probably because of its atmospheric transport away from areas of use. Toxaphene's complex nature makes accurate quantitation difficult. I have developed a computer program to automate quantitation, thus decreasing the time required for analysis while maintaining precise quantitation. I have shown that toxaphene in lake trout (Salvelinus namaycush) and rainbow smelt (Osmerus mordax) taken from Lake Superior have not decreased as they have in the four other Great Lakes from the time of the ban though 1992. This result could be due to three possibilities: ( a) There had been a food chain perturbation that made the 1982 concentrations unusually low. (b) The physical properties of Lake Superior make the loss rate significantly lower than the other Great Lakes. (c) There are current sources of toxaphene entering the Lake Superior basin. I analyzed an extended time series of lake trout from Lake Superior and from northern Lake Michigan to test the first two hypotheses. The concentrations of toxaphene have been constant in trout from Lake Superior since the late 1970's, so hypothesis a can be negated. The northern Lake Michigan samples did not decline as greatly as the southern basin samples, so hypothesis b can not be disproved. To determine the atmospheric deposition of toxaphene to Lake Superior, I analyzed air samples collected every twelve days for sixteen months at Eagle Harbor, Michigan. The concentrations of toxaphene in these samples are similar to those found in recent studies of air collected at Traverse City, MI., but significantly lower than samples taken at a land based site in southern Ontario in 1988 and 1989. This difference in concentration may (or may not) be due to differences in sampling times or locations or

  19. Bioaccumulation of toxaphene congeners in the lake superior food web (United States)

    Muir, D.C.G.; Whittle, D.M.; De Vault, D. S.; Bronte, C.R.; Karlsson, H.; Backus, S.; Teixeira, C.


    The bioaccumulation and biotransformation of toxaphene was examined in the food webs of Lake Superior and Siskiwit Lake (Isle Royale) using congener specific analysis as well as stable isotope ratios of carbon and nitrogen to characterize food webs. Toxaphene concentrations (calculated using technical toxaphene) in lake trout (Salvelinus namaycush) from the western basin of Lake Superior (N = 95) averaged (±SD) 889 ± 896 ng/g wet wt and 60 ± 34 ng/g wet wt in Siskiwit Lake. Major congeners in lake trout were B8-789 (P38), B8-2226 (P44), B9-1679 (P50), and B9-1025 (P62). Toxaphene concentrations were found to vary seasonally, especially in lower food web organisms in Lake Superior and to a lesser extent in Siskiwit Lake. Toxaphene concentrations declined significantly in lake herring (Coregonus artedii), rainbow smelt (Omerus mordax), and slimy sculpin (Cottus cognatus) as well as in zooplankton (> 102 &mn;m) and Mysis (Mysis relicta) between May and October. The seasonal variation may reflect seasonal shifts in the species abundance within the zooplankton community. Trophic magnification factors (TMF) derived from regressions of toxaphene congener concentrations versus δ15N were > 1 for most octa- and nonachlorobornanes in Lake Superior except B8-1413 (P26) and B9-715. Log bioaccumulation factors (BAFs) for toxaphene congeners in lake trout (ng/g lipid/ng/L dissolved) ranged from 4.54 to 9.7 and were significantly correlated with log octanol-water partition coefficients. TMFs observed for total toxaphene and congener B9-1679 in Lake Superior were similar to those in Arctic lakes, as well as to previous studies in the Great Lakes, which suggests that the bioaccumulation behavior of toxaphene is similar in pelagic food webs of large, cold water systems. However, toxaphene concentrations were lower in lake trout from Siskiwit Lake and lakes in northwestern Ontario than in Lake Superior possibly because of shorter food chains and greater reliance on zooplankton or

  20. Using High-Resolution Models to Predict the Effects of Climate Change on Aquatic Ecosystems in the Crown of the Continent (United States)

    Jones, L.; Muhlfeld, C.; Marshall, L. A.


    Climate trends and projections have prompted interest in assessing the thermal sensitivity of aquatic species. How species will adapt and respond to these changes is uncertain, however, climatic and hydrologic changes may shift species habitat distributions and physiological functions both spatially and temporally. This is particularly true for salmonids (e.g., trout, char, and salmon), which are cold-water species strongly influenced by changes in temperature, flow, and physical habitat conditions. Therefore, understanding how habitats are likely to change and how species may respond to changes in climatic conditions is critical for developing conservation and management strategies. The purpose of this study is to develop a high-resolution stream temperature model for the Crown of the Continent Ecosystem (CCE) to simulate potential climate change impacts on thermal regimes throughout the riverscape. A spatially explicit statistical regression model is coupled with high-resolution climate data such as air temperature, precipitation, solar radiation, baseflow and surface runoff. This empirically based model is used to predict daily stream temperatures under historic, current and forecasted climate conditions. The model is parameterized with empirical stream temperature data, which has been gathered from agencies across the region. The current database of empirical stream temperature data consists of over 800 sites throughout the CCE, which provide time series data to the model application. The biological integration and application of this model is on bull trout (Salvelinus confluentus) populations within the CCE. The model will be used to assess species vulnerabilities caused by spatial and temporal changes in stream temperature and hydrology. By evaluating the magnitude, timing and duration of climatic changes on the riverscape, we can more accurately assess potential vulnerabilities of critical life history traits, such as growth potential, spawning migrations

  1. Assessment of Native Salmonids Above Hells Canyon Dam, Idaho, 2004-2005 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Kevin A.; Lamansky, Jr., James A. (Idaho Department of Fish and Game, Boise, ID)


    In the western United States, exotic brook trout Salvelinus fontinalis frequently have a deleterious effect on native salmonids, and biologists often attempt to remove brook trout in streams using electrofishing. Although the success of electrofishing removal projects typically is low, few studies have assessed the underlying mechanisms of failure, especially in terms of compensatory responses. We evaluated the effectiveness of a three-year removal project in reducing brook trout and enhancing native salmonids in 7.8 km of an Idaho stream and looked for brook trout compensatory responses such as decreased natural mortality, increased growth, increased fecundity at length, or earlier maturation. Due to underestimates of the distribution of brook trout in the first year and personnel shortages in the third year, the multiagency watershed advisory group that performed the project fully treated the stream (i.e. multipass removals over the entire stream) in only one year. In 1998, 1999, and 2000, a total of 1,401, 1,241, and 890 brook trout were removed, respectively. For 1999 and 2000, an estimated 88 and 79% of the total number of brook trout in the stream were removed. For the section of stream that was treated in all years, the abundance of age-1 and older brook trout decreased by 85% from 1998 to 2003. In the same area, the abundance of age-0 brook trout decreased 86% from 1998 to 1999 but by 2003 had rebounded to near the original abundance. Abundance of native redband trout Oncorhynchus mykiss decreased for age-1 and older fish but did not change significantly for age-0 fish. Despite high rates of removal, total annual survival rate for brook trout increased from 0.08 {+-} 0.02 in 1998 to 0.20 {+-} 0.04 in 1999 and 0.21 {+-} 0.04 in 2000. Growth of age-0 brook trout was significantly higher in 2000 (the year after their abundance was lowest) compared to other years, and growth of age-1 and age-2 brook trout was significantly lower following the initial removal

  2. A decision-analytic approach to the optimal allocation of resources for endangered species consultation (United States)

    Converse, Sarah J.; Shelley, Kevin J.; Morey, Steve; Chan, Jeffrey; LaTier, Andrea; Scafidi, Carolyn; Crouse, Deborah T.; Runge, Michael C.


    The resources available to support conservation work, whether time or money, are limited. Decision makers need methods to help them identify the optimal allocation of limited resources to meet conservation goals, and decision analysis is uniquely suited to assist with the development of such methods. In recent years, a number of case studies have been described that examine optimal conservation decisions under fiscal constraints; here we develop methods to look at other types of constraints, including limited staff and regulatory deadlines. In the US, Section Seven consultation, an important component of protection under the federal Endangered Species Act, requires that federal agencies overseeing projects consult with federal biologists to avoid jeopardizing species. A benefit of consultation is negotiation of project modifications that lessen impacts on species, so staff time allocated to consultation supports conservation. However, some offices have experienced declining staff, potentially reducing the efficacy of consultation. This is true of the US Fish and Wildlife Service's Washington Fish and Wildlife Office (WFWO) and its consultation work on federally-threatened bull trout (Salvelinus confluentus). To improve effectiveness, WFWO managers needed a tool to help allocate this work to maximize conservation benefits. We used a decision-analytic approach to score projects based on the value of staff time investment, and then identified an optimal decision rule for how scored projects would be allocated across bins, where projects in different bins received different time investments. We found that, given current staff, the optimal decision rule placed 80% of informal consultations (those where expected effects are beneficial, insignificant, or discountable) in a short bin where they would be completed without negotiating changes. The remaining 20% would be placed in a long bin, warranting an investment of seven days, including time for negotiation. For formal

  3. Comparisons of likelihood and machine learning methods of individual classification (United States)

    Guinand, B.; Topchy, A.; Page, K.S.; Burnham-Curtis, M. K.; Punch, W.F.; Scribner, K.T.


    Classification methods used in machine learning (e.g., artificial neural networks, decision trees, and k-nearest neighbor clustering) are rarely used with population genetic data. We compare different nonparametric machine learning techniques with parametric likelihood estimations commonly employed in population genetics for purposes of assigning individuals to their population of origin (“assignment tests”). Classifier accuracy was compared across simulated data sets representing different levels of population differentiation (low and high FST), number of loci surveyed (5 and 10), and allelic diversity (average of three or eight alleles per locus). Empirical data for the lake trout (Salvelinus namaycush) exhibiting levels of population differentiation comparable to those used in simulations were examined to further evaluate and compare classification methods. Classification error rates associated with artificial neural networks and likelihood estimators were lower for simulated data sets compared to k-nearest neighbor and decision tree classifiers over the entire range of parameters considered. Artificial neural networks only marginally outperformed the likelihood method for simulated data (0–2.8% lower error rates). The relative performance of each machine learning classifier improved relative likelihood estimators for empirical data sets, suggesting an ability to “learn” and utilize properties of empirical genotypic arrays intrinsic to each population. Likelihood-based estimation methods provide a more accessible option for reliable assignment of individuals to the population of origin due to the intricacies in development and evaluation of artificial neural networks. In recent years, characterization of highly polymorphic molecular markers such as mini- and microsatellites and development of novel methods of analysis have enabled researchers to extend investigations of ecological and evolutionary processes below the population level to the level of

  4. Captive Rearing Initiative for Salmon River Chinook Salmon, 1998-1999 Progress Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hassemer, Peter F.


    these five were spawned out, one was partially spawned, and three died before depositing eggs. However, much of the spawning related behavior observed involved female chinook salmon paired with male bull trout Salvelinus confluentus. Two female carcasses from the East Fork Salmon River were recovered and examined for egg retention. One of these had spawned and one had not.

  5. Distribution and Movement of Bull Trout in the Upper Jarbidge River Watershed, Nevada (United States)

    Allen, M. Brady; Connolly, Patrick J.; Mesa, Matthew G.; Charrier, Jodi; Dixon, Chris


    In 2006 and 2007, we surveyed the occurrence of bull trout (Salvelinus confluentus), the relative distributions of bull trout and redband trout (Oncorhynchus mykiss), and stream habitat conditions in the East and West Forks of the Jarbidge River in northeastern Nevada and southern Idaho. We installed passive integrated transponder (PIT) tag interrogation systems at strategic locations within the watershed, and PIT-tagged bull trout were monitored to evaluate individual fish growth, movement, and the connectivity of bull trout between streams. Robust bull trout populations were found in the upper portions of the East Fork Jarbidge River, the West Fork Jarbidge River, and in the Pine, Jack, Dave, and Fall Creeks. Small numbers of bull trout also were found in Slide and Cougar Creeks. Bull trout were numerically dominant in the upper portions of the East Fork Jarbidge River, and in Fall, Dave, Jack, and Pine Creeks, whereas redband trout were numerically dominant throughout the rest of the watershed. The relative abundance of bull trout was notably higher at altitudes above 2,100 m. This study was successful in documenting bull trout population connectivity within the West Fork Jarbidge River, particularly between West Fork Jarbidge River and Pine Creek. Downstream movement of bull trout to the confluence of the East Fork and West Fork Jarbidge River both from Jack Creek (rkm 16.6) in the West Fork Jarbidge River and from Dave Creek (rkm 7.5) in the East Fork Jarbidge River was detected. Although bull trout exhibited some downstream movement during the spring and summer, much of their emigration occurred in the autumn, concurrent with decreasing water temperatures and slightly increasing flows. The bull trout that emigrated were mostly age-2 or older, but some age-1 fish also emigrated. Upstream movement by bull trout was detected less than downstream movement. The overall mean annual growth rate of bull trout in the East Fork and West Fork Jarbidge River was 36 mm

  6. Monitor and Protect Wigwam River Bull Trout for Koocanusa Reservoir; Skookumchuck Creek Juvenile Bull Trout and Fish Habitat Monitoring Program, Annual Report 2002.

    Energy Technology Data Exchange (ETDEWEB)

    Cope, R.


    The Skookumchuck Creek juvenile bull trout (Salvelinus confluentus) and fish habitat-monitoring program is a co-operative initiative of the British Columbia Ministry of Water, Land, and Air Protection and Bonneville Power Administration. This project was commissioned in planning for fish habitat protection and forest development within the Skookumchuck Creek watershed and was intended to expand upon similar studies initiated within the Wigwam River from 2000 to 2002. The broad intent is to develop a better understanding of juvenile bull trout and Westslope cutthroat trout recruitment and the ongoing hydrologic and morphologic processes, especially as they relate to spawning and rearing habitat quality. The 2002 project year represents the first year of a long-term bull trout-monitoring program with current studies focused on collecting baseline information. This report provides a summary of results obtained to date. Bull trout represented 72.4% of the catch. Fry dominated the catch because site selection was biased towards electrofishing sample sites which favored high bull trout fry capture success. The mean density of all juvenile bull trout was estimated to be 6.6 fish/100m{sup 2}. This represents one-half the densities reported for the 2002 Wigwam River enumeration program, even though enumeration of bull trout redds was an order of magnitude higher for the Wigwam River. Typically, areas with combined fry and juvenile densities greater than 1.5 fish per 100 m{sup 2} are cited as critical rearing areas. Trends in abundance appeared to be related to proximity to spawning areas, bed material size, and water depth. Cover components utilized by juvenile and adult bull trout and cutthroat trout were interstices, boulder, depth, overhead vegetation and LWD. The range of morphological stream types encompass the stable and resilient spectrum (C3(1), C3 and B3c). The Skookumchuck can be generalized as a slightly entrenched, meandering, riffle-pool, cobble dominated

  7. Adaptive responses of energy storage and fish life histories to climatic gradients. (United States)

    Giacomini, Henrique C; Shuter, Brian J


    Energy storage is a common adaptation of fish living in seasonal environments. For some species, the energy accumulated during the growing season, and stored primarily as lipids, is crucial to preventing starvation mortality over winter. Thus, in order to understand the adaptive responses of fish life history to climate, it is important to determine how energy should be allocated to storage and how it trades off with the other body components that contribute to fitness. In this paper, we extend previous life history theory to include an explicit representation of how the seasonal allocation of energy to storage acts as a constraint on fish growth. We show that a strategy that privileges allocation to structural mass in the first part of the growing season and switches to storage allocation later on, as observed empirically in several fish species, is the strategy that maximizes growth efficiency and hence is expected to be favored by natural selection. Stochastic simulations within this theoretical framework demonstrate that the relative performance of this switching strategy is robust to a wide range of fluctuations in growing season length, and to moderate short-term (i.e., daily) fluctuations in energy intake and/or expenditure within the growing season. We then integrate this switching strategy with a biphasic growth modeling framework to predict typical growth rates of walleye Sander vitreus, a cool water species, and lake trout Salvelinus namaycush, a cold water specialist, across a climatic gradient in North America. As predicted, growth rates increased linearly with the duration of the growing season. Regression line intercepts were negative, indicating that growth can only occur when growing season length exceeds a threshold necessary to produce storage for winter survival. The model also reveals important differences between species, showing that observed growth rates of lake trout are systematically higher than those of walleye in relatively colder lakes

  8. Movement of bull trout in the upper Jarbidge River watershed, Idaho and Nevada, 2008-09--A supplement to Open-File Report 2010-1033 (United States)

    Munz, Carrie S.; Allen, M. Brady; Connolly, Patrick J.


    We monitored bull trout (Salvelinus confluentus) in 2008 and 2009 as a continuation of our work in 2006 and 2007, which involved the tagging of 1,536 bull trout with passive integrated transponder (PIT) tags in the East Fork Jarbidge River and West Fork Jarbidge River and their tributaries in northeastern Nevada and southern Idaho. We installed PIT tag interrogation systems (PTISs) at established locations soon after ice-out, and maintained the PTISs in order to collect information on bull trout movements through December of each year. We observed a marked increase of movement in 2008 and 2009. Bull trout tagged in the uppermost portions of the East Fork Jarbidge River at altitudes greater than 2,100 meters moved to the confluence of the East Fork Jarbidge River and West Fork Jarbidge River in summer and autumn. Ten bull trout tagged upstream of the confluence of Pine Creek and the West Fork Jarbidge River moved downstream and then upstream in the East Fork Jarbidge River, and then past the PTIS at Murphy Hot Springs (river kilometer [rkm] 4.1). Two of these fish ascended Dave Creek, a tributary of the East Fork Jarbidge River, past the PTIS at rkm 0.4. One bull trout that was tagged at rkm 11 in Dave Creek on June 28, 2007 moved downstream to the confluence of the East Fork Jarbidge River and West Fork Jarbidge River (rkm 0) on July 28, 2007, and it was then detected in the West Fork Jarbidge River moving past our PTIS at rkm 15 on May 4, 2008. Combined, the extent and types of bull trout movements observed indicated that the primarily age-1 and age-2 bull trout that we tagged in 2006 and 2007 showed increased movement with age and evidence of a substantial amount of fluvial life history. The movements suggest strong connectivity between spawning areas and downstream mainstem areas, as well as between the East Fork Jarbidge River and West Fork Jarbidge River.

  9. Methow and Columbia Rivers studies: summary of data collection, comparison of database structure and habitat protocols, and impact of additional PIT tag interrogation systems to survival estimates, 2008-2012 (United States)

    Martens, Kyle D.; Tibbits, Wesley T.; Watson, Grace A.; Newsom, Michael A.; Connolly, Patrick J.


    The U.S. Geological Survey (USGS) received funding from the Bureau of Reclamation (Reclamation) to provide monitoring and evaluation on the effectiveness of stream restoration efforts by Reclamation in the Methow River watershed. This monitoring and evaluation program is designed to partially fulfill Reclamation’s part of the 2008 Biological Opinion for the Federal Columbia River Power System that includes a Reasonable and Prudent Alternative (RPA) to protect listed salmon and steelhead across their life cycle. The target species in the Methow River for the restoration effort include Upper Columbia River (UCR) spring Chinook salmon (Oncorhynchus tshawytscha), UCR steelhead (Oncorhynchus mykiss), and bull trout (Salvelinus confluentus), which are listed as threatened or endangered under the Endangered Species Act. Since 2004, the USGS has completed two projects of monitoring and evaluation in the Methow River watershed. The first project focused on the evaluation of barrier removal and steelhead recolonization in Beaver Creek with Libby and Gold Creeks acting as controls. The majority of this work was completed by 2008, although some monitoring continued through 2012. The second project (2008–2012) evaluated the use and productivity of the middle Methow River reach (rkm 65–80) before the onset of multiple off-channel restoration projects planned by the Reclamation and Yakama Nation. The upper Methow River (upstream of rkm 80) and Chewuch River serve as reference reaches and the Methow River downstream of the Twisp River (downstream of rkm 65) serves as a control reach. Restoration of the M2 reach was initiated in 2012 and will be followed by a multi-year, intensive post-evaluation period. This report is comprised of three chapters covering different aspects of the work completed by the USGS. The first chapter is a review of data collection that documents the methods used and summarizes the work done by the USGS from 2008 through 2012. This data summary was

  10. A regional neural network model for predicting mean daily river water temperature (United States)

    Wagner, Tyler; DeWeber, Jefferson Tyrell


    Water temperature is a fundamental property of river habitat and often a key aspect of river resource management, but measurements to characterize thermal regimes are not available for most streams and rivers. As such, we developed an artificial neural network (ANN) ensemble model to predict mean daily water temperature in 197,402 individual stream reaches during the warm season (May–October) throughout the native range of brook trout Salvelinus fontinalis in the eastern U.S. We compared four models with different groups of predictors to determine how well water temperature could be predicted by climatic, landform, and land cover attributes, and used the median prediction from an ensemble of 100 ANNs as our final prediction for each model. The final model included air temperature, landform attributes and forested land cover and predicted mean daily water temperatures with moderate accuracy as determined by root mean squared error (RMSE) at 886 training sites with data from 1980 to 2009 (RMSE = 1.91 °C). Based on validation at 96 sites (RMSE = 1.82) and separately for data from 2010 (RMSE = 1.93), a year with relatively warmer conditions, the model was able to generalize to new stream reaches and years. The most important predictors were mean daily air temperature, prior 7 day mean air temperature, and network catchment area according to sensitivity analyses. Forest land cover at both riparian and catchment extents had relatively weak but clear negative effects. Predicted daily water temperature averaged for the month of July matched expected spatial trends with cooler temperatures in headwaters and at higher elevations and latitudes. Our ANN ensemble is unique in predicting daily temperatures throughout a large region, while other regional efforts have predicted at relatively coarse time steps. The model may prove a useful tool for predicting water temperatures in sampled and unsampled rivers under current conditions and future projections of climate

  11. Captive Rearing Initiative for Salmon River Chinook Salmon, 1999 Progress Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hassemer, Peter F.


    these five were spawned out, one was partially spawned, and three died before depositing eggs. However, much of the spawning related behavior observed involved female chinook salmon paired with male bull trout Salvelinus confluentus. Two female carcasses from the East Fork Salmon River were recovered and examined for egg retention. One of these had spawned and one had not.

  12. Lake Pend Oreille Predation Research, Annual Report 2002-2003.

    Energy Technology Data Exchange (ETDEWEB)

    Bassista, Thomas


    During August 2002 we conducted a hydroacoustic survey to enumerate pelagic fish >406 mm in Lake Pend Oreille, Idaho. The purpose of this survey was to determine a collective lakewide biomass estimate of pelagic bull trout Salvelinus confluentus, rainbow trout Oncorhynchus mykiss, and lake trout S. namaycush and compare it to pelagic prey (kokanee salmon O. nerka) biomass. By developing hydroacoustic techniques to determine the pelagic predator to prey ratio, we can annually monitor their balance. Hydroacoustic surveys were also performed during December 2002 and February 2003 to investigate the effectiveness of autumn and winter surveys for pelagic predators. The inherent problem associated with hydroacoustic sampling is the inability to directly identify fish species. Therefore, we utilized sonic tracking techniques to describe rainbow trout and lake trout habitat use during our winter hydroacoustic survey to help identify fish targets from the hydroacoustic echograms. During August 2002 we estimated there were 39,044 pelagic fish >406 mm in Lake Pend Oreille (1.84 f/ha). Based on temperature and depth utilization, two distinct groups of pelagic fish >406 mm were located during August; one group was located between 10 and 35 m and the other between 40 and 70 m. The biomass for pelagic fish >406 mm during August 2002 was 73 t (metric ton). This would account for a ratio of 1 kg of pelagic predator for every 2.63 kg of kokanee prey, assuming all pelagic fish >406 mm are predators. During our late fall and winter hydroacoustic surveys, pelagic fish >406 mm were observed at lake depths between 20 and 90 m. During late fall and winter, we tracked three rainbow trout (168 habitat observations) and found that they mostly occupied pelagic areas and predominantly stayed within the top 10 m of the water column. During late fall (one lake trout) and winter (four lake trout), we found that lake trout (184 habitat observations) utilized benthic-nearshore areas 65% of the time

  13. Corroborating Structural/Spatial Treatments A Brook Trout Habitat Suitability Index Case Study%动物栖息地结构、场地整治方法论证 溪红点鲑栖息地适宜性指标案例研究

    Institute of Scientific and Technical Information of China (English)

    乔·布莱恩·布雷; 杨云峰


    规划师、设计师、环境保护论者、市民以及政府官员都对环境的评估和管理方法感兴趣。其中一种评估和管理野生动物栖息地的方法最先由美国政府机构研发的数值/定量栖息地模型技术。在笔者的研究课题中,调查了美国密歇根州三条河流中溪红点鲑的栖息地适宜性模型。该研究结果表明栖息地适宜性模型的平方乘以系数208.069所预测的每一研究河段的鱼类生物量的数值,在79.5%的研究区域有效。经过验证,该模型能够用于监测在研究区域内的溪红点鲑。%Planners,designers,environmentalists,citizens,and government officials are interested in methods to assess and manage the environment.One method to assess and manage wildlife habitat is the numerical/quantitative habitat modeling technique developed primarily by governmental agencies in the United States of America.In my study I investigated the habitat suitability model of the Brook Trout(Salvelinus fontinals,Mitchill 1814) in three Michigan rivers.The results of the study indicated that the habitat suitability model squared times the coefficient of 208.069 predicts the amount of fish biomass per study reach(p0.001),explaining 79.5% of the variance.The validation of this equation suggests that the model can be employed to manage Brook Trout within the study area.

  14. Using accelerated life testing procedures to compare the relative sensitivity of rainbow trout and the federally listed threatened bull trout to three commonly used rangeland herbicides (picloram, 2,4-D, and clopyralid) (United States)

    Fairchild, J.F.; Allert, A.; Sappington, L.S.; Nelson, K.J.; Valle, J.


    We conducted 96-h static acute toxicity studies to evaluate the relative sensitivity of juveniles of the threatened bull trout (Salvelinus confluentus) and the standard cold-water surrogate rainbow trout (Onchorhyncus mykiss) to three rangeland herbicides commonly used for controlling invasive weeds in the northwestern United States. Relative species sensitivity was compared using three procedures: standard acute toxicity testing, fractional estimates of lethal concentrations, and accelerated life testing chronic estimation procedures. The acutely lethal concentrations (ALC) resulting in 50% mortality at 96 h (96-h ALC50s) were determined using linear regression and indicated that the three herbicides were toxic in the order of picloram acid > 2,4-D acid > clopyralid acid. The 96-h ALC50 values for rainbow trout were as follows: picloram, 41 mg/L; 2.4-D, 707 mg/L; and clopyralid, 700 mg/L. The 96-h ALC50 values for bull trout were as follows: picloram, 24 mg/L; 2.4-D, 398 mg/L; and clopyralid, 802 mg/L. Fractional estimates of safe concentrations, based on 5% of the 96-h ALC50, were conservative (overestimated toxicity) of regression-derived 96-h ALC5 values by an order of magnitude. Accelerated life testing procedures were used to estimate chronic lethal concentrations (CLC) resulting in 1% mortality at 30 d (30-d CLC1) for the three herbicides: picloram (1 mg/L rainbow trout, 5 mg/L bull trout), 2,4-D (56 mg/L rainbow trout, 84 mg/L bull trout), and clopyralid (477 mg/L rainbow trout; 552 mg/L bull trout). Collectively, the results indicated that the standard surrogate rainbow trout is similar in sensitivity to bull trout. Accelerated life testing procedures provided cost-effective, statistically defensible methods for estimating safe chronic concentrations (30-d CLC1s) of herbicides from acute toxicity data because they use statistical models based on the entire mortality:concentration: time data matrix. ?? 2008 SETAC.

  15. Piscivorous fish exhibit temperature-influenced binge feeding during an annual prey pulse (United States)

    Furey, Nathan B.; Hinch, Scott G.; Mesa, Matthew G.; Beauchamp, David A.


    Understanding the limits of consumption is important for determining trophic influences on ecosystems and predator adaptations to inconsistent prey availability. Fishes have been observed to consume beyond what is sustainable (i.e. digested on a daily basis), but this phenomenon of hyperphagia (or binge-feeding) is largely overlooked. We expect hyperphagia to be a short-term (1-day) event that is facilitated by gut volume providing capacity to store consumed food during periods of high prey availability to be later digested.We define how temperature, body size and food availability influence the degree of binge-feeding by comparing field observations with laboratory experiments of bull trout (Salvelinus confluentus), a large freshwater piscivore that experiences highly variable prey pulses. We also simulated bull trout consumption and growth during salmon smolt outmigrations under two scenarios: 1) daily consumption being dependent upon bioenergetically sustainable rates and 2) daily consumption being dependent upon available gut volume (i.e. consumption is equal to gut volume when empty and otherwise ‘topping off’ based on sustainable digestion rates).One-day consumption by laboratory-held bull trout during the first day of feeding experiments after fasting exceeded bioenergetically sustainable rates by 12- to 87-fold at low temperatures (3 °C) and by  ˜1·3-fold at 20 °C. The degree of binge-feeding by bull trout in the field was slightly reduced but largely in agreement with laboratory estimates, especially when prey availability was extremely high [during a sockeye salmon (Oncorhynchus nerka) smolt outmigration and at a counting fence where smolts are funnelled into high densities]. Consumption by bull trout at other settings were lower and more variable, but still regularly hyperphagic.Simulations demonstrated the ability to binge-feed increased cumulative consumption (16–32%) and cumulative growth (19–110%) relative to only feeding at

  16. Effects of Forest Harvesting on Ecosystem Health in the Headwaters of the New York City Water Supply, Catskill Mountains, New York (United States)

    McHale, Michael R.; Murdoch, Peter S.; Burns, Douglas A.; Baldigo, Barry P.


    The effects of forest clearcutting and selective harvesting on forest soils, soil and stream water chemistry, forest regrowth, and aquatic communities were studied in four small headwater catchments. This research was conducted to identify the sensitivity of forested ecosystems to forest disturbance in the northeastern United States. The study area was in the headwaters of the Neversink Reservoir watershed, part of the New York City water supply system, in the Catskill Mountains of southeastern New York. Two sub-catchments of the Shelter Creek watershed were selectively harvested, one in its northern half and one more heavily in its southern half in 1995?96, the Dry Creek watershed was clearcut in the winter of 1996?97, and the Clear Creek watershed was left undisturbed and monitored as a control site. Monitoring was conducted from 4 years before the harvests until 4 years after the harvests. Clearcutting caused a large release of nitrate (NO3-) from watershed soils and a concurrent release of inorganic monomeric aluminum (Alim), which is toxic to some aquatic biota. The increased soil NO3- concentrations measured after the harvest could be completely accounted for by the decrease in nitrogen (N) uptake by watershed trees, rather than an increase in N mineralization and nitrification. The large increase in stream water NO3- and Alim concentrations caused 100-percent mortality of caged brook trout (Salvelinus fontinalis) during the first year after the clearcut and adversely affected macroinvertebrate communities for 2 years after the harvest. Nutrient uptake and biomass accumulation increased in uncut mature trees after the two selective harvests. There was no increase in stream-water NO3- or Alim concentrations, and so there were no adverse affects on macroinvertebrate or trout communities. The amount of tree biomass that can be removed without causing a sharp increase in stream-water NO3- and Alim stream-water concentrations is unknown, but probably depends on

  17. Lake trout rehabilitation in Lake Ontario (United States)

    Elrod, Joseph H.; O'Gorman, Robert; Schneider, Clifford P.; Eckert, Thomas H.; Schaner, Ted; Bowlby, James N.; Schleen, Larry P.


    Attempts to maintain the native lake trout (Salvelinus namaycush) population in Lake Ontario by stocking fry failed and the species was extirpated by the 1950s. Hatchery fish stocked in the 1960s did not live to maturity because of sea lamprey (Petromyzon marinus) predation and incidental commercial harvest. Suppression of sea lampreys began with larvicide treatments of Lake Ontario tributaries in 1971 and was enhanced when the tributaries of Oneida Lake and Lake Erie were treated in the 1980s. Annual stocking of hatchery fish was resumed with the 1972 year class and peaked at about 1.8 million yearlings and 0.3 million fingerlings from the 1985–1990 year classes. Survival of stocked yearlings declined over 50% in the 1980 s and was negatively correlated with the abundance of lake trout > 550 mm long (r = −0.91, P < 0.01, n = 12). A slot length limit imposed by the State of New York for the 1988 fishing season reduced angler harvest. Angler harvest in Canadian waters was 3 times higher in eastern Lake Ontario than in western Lake Ontario. For the 1977–1984 year classes, mean annual survival rate of lake trout age 6 and older was 0.45 (range: 0.35–0.56). In U.S. waters during 1985–1992, the total number of lake trout harvested by anglers was about 2.4 times greater than that killed by sea lampreys. The number of unmarked lake trout < 250 mm long in trawl catches in 1978–1992 was not different from that expected due to loss of marks and failure to apply marks at the hatchery, and suggested that recruitment of naturally-produced fish was nil. However, many of the obstacles which may have impeded lake trout rehabilitation in Lake Ontario during the 1980s are slowly being removed, and there are signs of a general ecosystem recovery. Significant recruitment of naturally produced lake trout by the year 2000, one interim objective of the rehabilitation plan for the Lake, may be achieved.

  18. Wigwam River McNeil Substrate Sampling Program : 1998-2002 Summary Report.

    Energy Technology Data Exchange (ETDEWEB)

    Tepper, Herb


    The Wigwam River is an important fisheries stream in the East Kootenay region of British Columbia that supports healthy populations of both bull trout (Salvelinus confluentus) and Westslope cutthroat trout (Oncorhynchus clarki lewisi). The river has been characterized as the single most important bull trout spawning steam in the Kootenay Region (Baxter and Westover 2000), and thus has been the focus of numerous studies in the last ten years (Cope 1998; Cope and Morris 2001; Cope, Morris and Bisset 2002; Kohn Crippen Consultants Ltd. 1998; Westover 1999a; Westover 1999b; Westover and Conroy 1997). Although bull trout populations in the East Kootenay region remain healthy, bull trout populations in other parts of British Columbia and within their traditional range in northwestern United States have declined. Thus, bull trout were blue listed as vulnerable in British Columbia by the B.C. Conservation Data Centre (Cannings 1993) and remain a species of special concern. Bull trout in the north-western United States, within the Columbia River watershed, were listed as threatened in 1998 under the Endangered Species Act by the U.S. Fish and Wildlife Service. In 1999, the Ministry of Water, Land and Air Protection applied and received funding from the Bonneville Power Administration (BPA) to assess and monitor the status of wild, native stocks of bull trout in tributaries to Lake Koocanusa (Libby Reservoir) and the upper Kootenay River. The purpose of this report is to summarize one of the many studies undertaken to ''Monitor and Protect Bull Trout for Koocanusa Reservoir'' (BPA Project Number 2000-04-00). Three permanent sampling sites were established on the Wigwam River in April 1998. At each site, substrate samples were obtained using a McNeil Core sampler in April of each year from 1998 to 2002. The objectives of this study were to assess the quality of stream-bed substrates used by bull trout for spawning prior to major resource development in the

  19. Kootenai River Fisheries Investigations; Rainbow and Bull Trout Recruitment, 2002-2003 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Walters, Jody P.


    Rainbow trout Oncorhynchus mykiss provide the most important sport fishery in the Kootenai River, Idaho, but densities and catch rates are low. Low recruitment is one possible factor limiting the rainbow trout population. Bull trout Salvelinus confluentus also exist in the Kootenai River, but little is known about this population. Research reported here addresses the following objectives for the Kootenai River, Idaho: increase rainbow trout recruitment, identify rainbow and bull trout spawning tributaries and migration timing, establish baseline data on bull trout redd numbers in tributaries, and improve the rainbow trout population size structure. Six adult rainbow trout were moved to spawning habitat upstream of a potential migration barrier on Caboose Creek, but numbers of redds and age-0 out-migrants did not appear to increase relative to a reference stream. Measurements taken on the Moyie River indicated the gradient is inadequate to deliver suitable flows to a proposed rainbow trout spawning channel. Summer water temperatures measured in the Deep Creek drainage sometimes exceeded 24 C, higher than those reported as suitable for rainbow trout. Radio-tagged rainbow trout were located in Boulder Creek during the spring spawning season, and bull trout were located in the Moyie River and O'Brien Creek, Montana in the fall. Bull trout spawning migration timing was related to increases in Kootenai River flows. Bull trout redd surveys documented 19 redds on Boulder Creek and North and South Callahan creeks. Fall 2002 electrofishing showed that the Kootenai River rainbow trout proportional stock density was 54, higher than prior years when more liberal fishing regulations were in effect. Boulder Creek produces the highest number of age-0 rainbow trout out-migrants upstream of Bonners Ferry, but the survival rate of these out-migrants upon reaching the Kootenai River is unknown. Determining juvenile survival rates and sources of mortality could aid management

  20. Contrasting past and current numbers of bears visiting Yellowstone cutthroat trout streams (United States)

    Haroldson, Mark A.; Schwartz, Charles C.; , JUSTIN E. TEISBERG; , Kerry A. Gunther; , JENNIFER K. FORTIN; , CHARLES T. ROBBINS


    Spawning cutthroat trout (Oncorhynchus clarkii bouvieri) were historically abundant within tributary streams of Yellowstone Lake within Yellowstone National Park and were a highly digestible source of energy and protein for Yellowstone’s grizzly bears (Ursus arctos) and black bears (U. americanus). The cutthroat trout population has subsequently declined since the introduction of non-native lake trout (Salvelinus namaycush), and in response to effects of drought and whirling disease (Myxobolus cerebralis). The trout population, duration of spawning runs, and indices of bear use of spawning streams had declined in some regions of the lake by 1997–2000. We initiated a 3-year study in 2007 to assess whether numbers of spawning fish, black bears, and grizzly bears within and alongside stream corridors had changed since 1997– 2000. We estimated numbers of grizzly bears and black bears by first compiling encounter histories of individual bears visiting 48 hair-snag sites along 35 historically fished streams.We analyzed DNA encounter histories with Pradel-recruitment and Jolly-Seber (POPAN) capture-mark-recapture models. When compared to 1997–2000, the current number of spawning cutthroat trout per stream and the number of streams with cutthroat trout has decreased. We estimated that 48 (95% CI¼42–56) male and 23 (95% CI¼21–27) female grizzly bears visited the historically fished tributary streams during our study. In any 1- year, 46 to 59 independent grizzly bears (8–10% of estimated Greater Yellowstone Ecosystem population) visited these streams. When compared with estimates from the 1997 to 2000 study and adjusted for equal effort, the number of grizzly bears using the stream corridors decreased by 63%. Additionally, the number of black bears decreased between 64% and 84%. We also document an increased proportion of bears of both species visiting front-country (i.e., near human development) streams. With the recovery of cutthroat trout, we suggest bears

  1. Episodic acidification of small streams in the northeastern united states: Fish mortality in field bioassays (United States)

    Van Sickle, J.; Baker, J.P.; Simonin, H.A.; Baldigo, Barry P.; Kretser, W.A.; Sharpe, W.E.


    In situ bioassays were performed as part of the Episodic Response Project, to evaluate the effects of episodic stream acidification on mortality of brook trout (Salvelinus fontinalis) and forage fish species. We report the results of 122 bioassays in 13 streams of the three study regions: the Adirondack mountains of New York, the Catskill mountains of New York, and the Northern Appalachian Plateau of Pennsylvania. Bioassays during acidic episodes had significantly higher mortality than did bioassays conducted under nonacidic conditions, but there was little difference in mortality rates in bioassays experiencing acidic episodes and those experiencing acidic conditions throughout the test period. Multiple logistic regression models were used to relate bioassay mortality rates to summary statistics of time-varying stream chemistry (inorganic monomeric aluminum, calcium, pH, and dissolved organic carbon) estimated for the 20-d bioassay periods. The large suite of candidate regressors also included biological, regional, and seasonal factors, as well as several statistics summarizing various features of aluminum exposure duration and magnitude. Regressor variable selection and model assessment were complicated by multicol-linearity and overdispersion. For the target fish species, brook trout, bioassay mortality was most closely related to time-weighted median inorganic aluminum. Median Ca and minimum pH offered additional explanatory power, as did stream-specific aluminum responses. Due to high multicollinearity, the relative importance of different aluminum exposure duration and magnitude variables was difficult to assess, but these variables taken together added no significant explanatory power to models already containing median aluminum. Between 59 and 79% of the variation in brook trout mortality was explained by models employing between one and five regressors. Simpler models were developed for smaller sets of bioassays that tested slimy and mottled sculpin

  2. Thiamine Deficiency Complex Workshop final report: November 6-7, 2008, Ann Arbor, MI (United States)

    Honeyfield, Dale C.; Tillitt, Donald E.; Riley, Stephen C.


    Fry mortality which was first observed in the late 1960s in Great Lakes salmonines and in Baltic Sea salmon in 1974 has now been linked to thiamine deficiency (historically referred to as Early Mortality Syndrome, or EMS and M74, respectively). Over the past 14 years significant strides have been made in our understanding of this perplexing problem. It is now known that thiamine deficiency causes embryonic mortality in these salmonids. Both overt mortality and secondary effects of thiamine deficiency are observed in juvenile and adult animals. Collectively the morbidity and mortality (fry and adult mortality, secondary metabolic and behavior affects in juveniles and adult fish) are referred to as Thiamine Deficiency Complex (TDC). A workshop was held in Ann Arbor, MI on 6-7 November 2008 that brought together 38 federal, state, provincial, tribal and university scientists to share information, present data and discuss the latest observations on thiamine status of aquatic animals with thiamine deficiency and the causative agent, thiaminase. Twenty presentations (13 oral and 7 posters) detailed current knowledge. In Lake Huron, low alewife Alosa pseudoharengus abundance has persisted and egg thiamine concentrations in salmonines continue to increase, along with evidence of natural reproduction in lake trout Salvelinus namaycush. Lake Michigan Chinook salmon Oncorhynchus tshawytscha appear to have a lower thiamine requirement than other salmonids in the lake. Lake Ontario American eel Anguilla rostrata foraging on alewife have approximately one third the muscle thiamine compared to eels not feeding on alewife, suggesting that eels may be suffering from thiamine deficiency. Secondary effects of low thiamine exist in Great Lakes salmonines and should not be ignored. Thiaminase activity in dreissenid mussels is extremely high but a connection to TDC has not been made. Thiaminase in net plankton was found more consistently in lakes Michigan and Ontario than other lakes

  3. Radiological impact of the nuclear power plant accident on freshwater fish in Fukushima: An overview of monitoring results. (United States)

    Wada, Toshihiro; Tomiya, Atsushi; Enomoto, Masahiro; Sato, Toshiyuki; Morishita, Daigo; Izumi, Shigehiko; Niizeki, Kouji; Suzuki, Shunji; Morita, Takami; Kawata, Gyo


    Radionuclide ((131)I, (134)Cs, and (137)Cs) concentrations of monitored freshwater fish species collected from different habitats (rivers, lakes, and culture ponds) in Fukushima Prefecture during March 2011-December 2014 (total 16 species, n = 2692) were analyzed to present a detailed description of radionuclide contamination after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, and to elucidate species-specific spatiotemporal declining trends of (137)Cs concentration for their respective habitats. Low concentrations of (131)I (≤24 Bq kg(-1)-wet) were detected from only 11 samples collected during March-June 2011, demonstrating that (131)I transferred to freshwater fish were not intense. In river and lake fishes, a more gradual decrease and higher radiocesium ((134)Cs, (137)Cs) concentrations were observed than in culture pond fishes, which strongly implied that radiocesium in freshwater fish species was mainly bioaccumulated through the food web in the wild. During 2011-2014, percentages above the Japanese regulatory limit of 100 Bq kg(-1)-wet for radiocesium in river and lake fish (14.0% and 39.6%, respectively) were higher than in monitored marine fish (9.9%), indicating longer-term contamination of freshwater fish species, especially in lakes. Higher radiocesium concentrations (maximum 18.7 kBq kg(-1)-wet in Oncorhynchus masou) were found in the northwestern areas from the FDNPP with higher deposition. However, radiocesium contamination levels were regarded as 1-2 orders of magnitude less than those after the Chernobyl accident. Lagged increase of (137)Cs concentration and longer ecological half-lives (Teco: 1.2-2.6 y in the central part of Fukushima Prefecture) were observed in carnivorous salmonids (O. masou, Salvelinus leucomaenis), whereas a rapid increase and decrease of (137)Cs concentration and shorter Teco (0.99 and 0.69 y) were found in herbivorous and planktivorous osmerids (Plecoglossus altivelis, Hypomesus nipponensis) with

  4. Bull Trout Population Assessment in the Columbia River Gorge : Annual Report 2000.

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, Jim; McPeak, Ron


    We summarized existing knowledge regarding the known distribution of bull trout (Salvelinus confluentus) across four sub-basins in the Columbia River Gorge in Washington. The Wind River, Little White Salmon River, White Salmon River, and the Klickitat River sub-basins were analyzed. Cold water is essential to the survival, spawning, and rearing of bull trout. We analyzed existing temperature data, installed Onset temperature loggers in the areas of the four sub-basins where data was not available, and determined that mean daily water temperatures were <15 C and appropriate for spawning and rearing of bull trout. We snorkel surveyed more than 74 km (46.25 mi.) of rivers and streams in the four sub-basins (13.8 km at night and 60.2 km during the day) and found that night snorkeling was superior to day snorkeling for locating bull trout. Surveys incorporated the Draft Interim Protocol for Determining Bull Trout Presence (Peterson et al. In Press). However, due to access and safety issues, we were unable to randomly select sample sites nor use block nets as recommended. Additionally, we also implemented the Bull Trout/Dolly Varden sampling methodology described in Bonar et al. (1997). No bull trout were found in the Wind River, Little White Salmon, or White Salmon River sub-basins. We found bull trout in the West Fork Klickitat drainage of the Klickitat River Sub-basin. Bull trout averaged 6.7 fish/100m{sup 2} in Trappers Creek, 2.6 fish/100m{sup 2} on Clearwater Creek, and 0.4 fish/100m{sup 2} in Little Muddy Creek. Bull trout was the only species of salmonid encountered in Trappers Creek and dominated in Clearwater Creek. Little Muddy Creek was the only creek where bull trout and introduced brook trout occurred together. We found bull trout only at night and typically in low flow regimes. A single fish, believed to be a bull trout x brook trout hybrid, was observed in the Little Muddy Creek. Additional surveys are needed in the West Fork Klickitat and mainstem

  5. Development and Application of a Decision Support System for Water Management Investigations in the Upper Yakima River, Washington (United States)

    Bovee, Ken D.; Waddle, Terry J.; Talbert, Colin; Hatten, James R.; Batt, Thomas R.


    The Yakima River Decision Support System (YRDSS) was designed to quantify and display the consequences of different water management scenarios for a variety of state variables in the upper Yakima River Basin, located in central Washington. The impetus for the YRDSS was the Yakima River Basin Water Storage Feasibility Study, which investigated alternatives for providing additional water in the basin for threatened and endangered fish, irrigated agriculture, and municipal water supply. The additional water supplies would be provided by combinations of water exchanges, pumping stations, and off-channel storage facilities, each of which could affect the operations of the Bureau of Reclamation's (BOR) five headwaters reservoirs in the basin. The driver for the YRDSS is RiverWare, a systems-operations model used by BOR to calculate reservoir storage, irrigation deliveries, and streamflow at downstream locations resulting from changes in water supply and reservoir operations. The YRDSS uses output from RiverWare to calculate and summarize changes at 5 important flood plain reaches in the basin to 14 state variables: (1) habitat availability for selected life stages of four salmonid species, (2) spawning-incubation habitat persistence, (3) potential redd scour, (4) maximum water temperatures, (5) outmigration for bull trout (Salvelinus confluentus) from headwaters reservoirs, (6) outmigration of salmon smolts from Cle Elum Reservoir, (7) frequency of beneficial overbank flooding, (8) frequency of damaging flood events, (9) total deliverable water supply, (10) total water supply deliverable to junior water rights holders, (11) end-of-year reservoir carryover, (12) potential fine sediment transport rates, (13) frequency of events capable of armor layer disruption, and (14) geomorphic work performed during each water year. Output of the YRDSS consists of a series of conditionally formatted scoring tables, wherein the changes to a state variable resulting from an operational

  6. Knowing for controlling: ecological effects of invasive vertebrates in Tierra del Fuego Conocer para controlar: efectos ecológicos de vertebrados invasores en Tierra del Fuego

    Directory of Open Access Journals (Sweden)



    Full Text Available The Tierra del Fuego (TDF archipelago is recognized as part o the last places on Earth that may still be considered wild. However, this condition may be threatened by the large number of invasive species present on the archipelago. These species can have significant effects on the ecology of the invaded ecosystems, at the genetic as well as at population, community and ecosystem levels. The aim of this study is to, by a bibliographic review, systematize existing information on the ecological impacts these species would be having on the TDF archipelago and detect information gaps in order to orient future research and effective management programs on these species. We restricted our review to vertebrate, non-marine invaders. We determined which species have invaded TDF, described their impacts on the archipelago and evaluated their potential impacts; this last issue was determined by reviewing some of the impacts these species have had in other geographic areas. Our findings indicate that at least nine vertebrate species (Salmo trutta, Salvelinus fontinalis, Oncorhynchus mykiss, Castor canadensis, Ondatra zibethicus, Oryctolagus cuniculus, Pseudalopex griseus, Mustela vison and Sus seroja have wild populations established away from human settlements in TDF. There is some scientific evidence on ecological impacts on the area for only five of these invaders, with the American beaver (Castor canadensis being the species monopolizing the greatest number of studies. These results contrast with the recognition, both in TDF and worldwide, of the potential of most of these species to cause significant ecological impacts, which makes it unlikely that the lack of verified impacts on TDF reflects an absence of significant effects of these invaders on the archipelago. We suggest that future research should focus on determining population density and distribution of these and other (i.e., feral species invasive vertebrates, as well as their impacts mainly on

  7. Synthesis and interpretation of surface-water quality and aquatic biota data collected in Shenandoah National Park, Virginia, 1979-2009 (United States)

    Jastram, John D.; Snyder, Craig D.; Hitt, Nathaniel P.; Rice, Karen C.


    ABSTRACT Shenandoah National Park in northern and central Virginia protects 777 square kilometers of mountain terrain in the Blue Ridge physiographic province and more than 90 streams containing diverse aquatic biota. Park managers and visitors are interested in the water quality of park streams and its ability to support healthy coldwater communities and species, such as the native brook trout (Salvelinus fontinalis), that are at risk in the eastern United States. Despite protection from local stressors, however, the water quality of streams in the park is at risk from many regional stressors, including atmospheric pollution, decline in the health of the surrounding forests because of invasive forest pests, and global climate change. In 2010, the U.S. Geological Survey, in cooperation with the National Park Service, undertook a study to compile, analyze, and synthesize available data on water quality, aquatic macroinvertebrates, and fish within Shenandoah National Park. Specifically, the effort focused on creating a comprehensive water-resources database for the park that can be used to evaluate temporal trends and spatial patterns in the available data, and characterizing those data to better understand interrelations among water quality, aquatic macroinvertebrates, fish, and the landscape. Data from three primary sources, namely the Shenandoah Watershed Study, the Shenandoah National Park Aquatic Macroinvertebrate Monitoring Program, and the Springs and Headwater Streams Study, were compiled and loaded into the National Park Service’s NPSTORET database. This effort yielded a comprehensive database containing nearly 1.3 million measurements of habitat characteristics, approximately 442,000 measurements of water-quality characteristics, and over 438,000 measurements of biological taxa (fish and aquatic macroinvertebrates), collected across 673 sites over a period of more than 30 years. Temporal trends in water quality indicate conflicting patterns in terms of

  8. Monitor and Protect Wigwam River Bull Trout for Koocanusa Reservoir; White River Bull Trout Enumeration Project Summary, Progress Report 2003.

    Energy Technology Data Exchange (ETDEWEB)

    Cope, R.


    This report summarizes the first year of a three-year bull trout (Salvelinus confluentus) enumeration project on the White River and is a co-operative initiative of the British Columbia Ministry of Water, Land, and Air Protection and Bonneville Power Administration. The White River has been identified as an important bull trout spawning tributary of the upper Kootenay River in southeastern British Columbia. The objective was to collect information on the returning adult spawning population to the White River through the use of a fish fence and traps, and to conduct redd surveys at the conclusion of spawning to provide an index of spawning escapement and distribution. The fence was installed on September 9th, 2003 and was operated continuously (i.e. no high-water or breaching events) until the fence was removed on October 9th, 2003. Estimation of the spawning population of White River bull trout was incomplete. This was due to a larger and more protracted out-migration than expected. As a result, the bull trout spawning population of the White River was estimated to be somewhere above 899 fish. In comparison, this represents approximately one third the population estimate of the 2003 Wigwam River bull trout spawning population. Based on redd index data, the number of bull trout per redd was over twice that of the Wigwam River or Skookumchuck Creek. This was expected as the index sites on the Wigwam River and Skookumchuck Creek cover the majority of the spawning area. This is not true on the White River. From previous redd counts, it is known that there are approximately twice as many redds in Blackfoot Creek as there are in the index site. Additionally, given the large size of the White River watershed and in particular, the large number of tributaries, there is a high likelihood that important bull trout spawning areas remain unidentified. Both floy tag and radio-telemetry data for the White River bull trout have identified extensive life history migrations

  9. Instream flow characterization of Upper Salmon River basin streams, central Idaho, 2005 (United States)

    Maret, Terry R.; Hortness, Jon E.; Ott, Douglas S.


    Anadromous fish populations in the Columbia River Basin have plummeted in the last 100 years. This severe decline led to Federal listing of Chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Oncorhynchus mykiss) stocks as endangered or threatened under the Endangered Species Act (ESA) in the 1990s. Historically, the upper Salmon River Basin (upstream of the confluence with the Pahsimeroi River) in Idaho provided migration corridors and significant habitat for these ESA-listed species, in addition to the ESA-listed bull trout (Salvelinus confluentus). Human development has modified the original streamflow conditions in many streams in the upper Salmon River Basin. Summer streamflow modifications resulting from irrigation practices, have directly affected quantity and quality of fish habitat and also have affected migration and (or) access to suitable spawning and rearing habitat for these fish. As a result of these ESA listings and Action 149 of the Federal Columbia River Power System Biological Opinion of 2000, the Bureau of Reclamation was tasked to conduct streamflow characterization studies in the upper Salmon River Basin to clearly define habitat requirements for effective species management and habitat restoration. These studies include collection of habitat and streamflow information for the Physical Habitat Simulation System (PHABSIM) model, a widely applied method to determine relations between habitat and discharge requirements for various fish species and life stages. Model simulation results can be used by resource managers to guide habitat restoration efforts by evaluating potential fish habitat and passage improvements by increasing or decreasing streamflow. In 2005, instream flow characterization studies were completed on Big Boulder, Challis, Bear, Mill, and Morgan Creeks. Continuous streamflow data were recorded upstream of all diversions on Big Boulder. Instantaneous measurements of discharge were also made at selected sites. In

  10. The physiology and toxicology of salmonid eggs and larvae in relation to water quality criteria

    Energy Technology Data Exchange (ETDEWEB)

    Finn, Roderick Nigel [Department of Biology, University of Bergen, Allegaten 41, N-5020 Bergen (Norway)]. E-mail:


    The purpose of this review is to collate physiological knowledge on salmonid eggs and larvae in relation to water quality criteria. Salmonid genera reviewed include Coregonus, Thymallus, Salvelinus, Salmo, and Oncorhynchus spp. When physiological data for salmonids are lacking, the zebrafish and medaka models are included. The primary focus is on the underlying mechanisms involved in the hydro-mineral, thermal, and respiratory biology with an extended section on the xenobiotic toxicology of the early stages. Past and present data reveal that the eggs of salmonids are among the largest shed by any broadcast spawning teleost. Once ovulated, the physicochemical properties of the ovarian fluid provide temporary protection from external perturbations and maintain the eggs in good physiological condition until spawning. Following fertilisation and during early development the major structures protecting the embryo from poor water quality are the vitelline membrane, the enveloping layer and the chorion. The vitelline membrane is one of the least permeable membranes known, while the semi-permeable chorion provides both physical and chemical defense against metals, pathogens, and xenobiotic chemicals. In part these structures explain the lower sensitivity of the eggs to chemical imbalance compared to the larvae, however the lower metabolic rate and the chronology of gene expression and translational control suggest that developmental competence also plays a decisive role. In addition, maternal effect genes provide a defense potential until the mid-blastula transition. The transition between maternal effect genes and zygotic genes is a critical period for the embryo. The perivitelline fluids are an important trap for cations, but are also the major barrier to diffusion of gases and solutes. Acidic environmental pH interferes with acid-base and hydromineral balance but also increases the risk of aluminium and heavy metal intoxication. These risks are ameliorated somewhat by

  11. Assessment of Native Salmonids Above Hells Canyon Dam, Idaho, 2003-2004 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Kevin A.; Lamansky, Jr., James A. (Idaho Department of Fish and Game, Boise, ID)


    Despite the substantial declines in distribution and abundance that the Yellowstone cutthroat trout Oncorhynchus clarkii bouvieri has experienced over the past century, quantitative evaluations of existing population sizes over broad portions of its historical range have not been made. In this study, we estimate trout abundance throughout the Upper Snake River basin in Idaho (and portions of adjacent states), based on stratified sample extrapolations of electrofishing surveys conducted at 961 study sites, the vast majority of which (84%) were selected randomly. Yellowstone cutthroat trout were the most widely distributed species of trout (caught at 457 study sites), followed by brook trout Salvelinus fontinalis (242 sites), rainbow trout O. mykiss and rainbow x cutthroat hybrids (136 sites), and brown trout Salmo trutta (70 sites). Of the sites that contained cutthroat trout, more than half did not contain any other species of trout. Where nonnative trout were sympatric with cutthroat trout, brook trout were most commonly present. In the 11 Geographic Management Units (GMUs) where sample size permitted abundance estimates, there were about 2.2 million trout {ge}100 mm, and of these, about one-half were cutthroat trout. Similarly, we estimated that about 2.0 million trout <100 mm were present, of which about 1.2 million were cutthroat trout. The latter estimate is biased low because our inability to estimate abundance of trout <100 mm in larger-order rivers negated our ability to account for them at all. Cutthroat trout were divided into approximately 70 subpopulations but estimates could be made for only 55 subpopulations; of these, 44 subpopulations contained more than 1,000 cutthroat trout and 28 contained more than 2,500 cutthroat trout. Using a logistic regression model to predict the number of spawning cutthroat trout at a given study site, we estimate that an average of about 30% of the cutthroat trout {ge}100 mm are spawners. We compared visually

  12. Hangman Restoration Project : Annual Report, August 1, 2001 - July 31, 2002.

    Energy Technology Data Exchange (ETDEWEB)

    Green, Gerald I.; Coeur D' Alene Tribe.


    The construction of hydroelectric facilities in the Columbia Basin resulted in the extirpation of anadromous fish stocks in Hangman Creek and its tributaries within the Coeur d'Alene Reservation. Thus, the Coeur d'Alene Indian Tribe was forced to rely more heavily on native fish stocks such as redband trout (Oncorhynchus mykiss garideini), westslope cutthroat trout (O. clarki lewisii) and bull trout (Salvelinus confluentus) as well as local wildlife populations. Additionally, the Tribe was forced to convert prime riparian habitat into agricultural lands to supply sustenance for their changed needs. Wildlife habitats within the portion of the Hangman Creek Watershed that lies within the Coeur d'Alene Indian Reservation have been degraded from a century of land management practices that include widespread conversion of native habitats to agricultural production and intensive silvicultural practices. Currently, wildlife and fish populations have been marginalized and water quality is significantly impaired. In the fall of 2000 the Coeur d'Alene Tribe Wildlife Program, in coordination with the Tribal Fisheries Program, submitted a proposal to begin addressing the degradations to functioning habitats within the Coeur d'Alene Reservation in the Hangman Watershed. That proposal led to the implementation of this project during BPA's FY2001 through FY2003 funding cycle. The project is intended to protect, restore and/or enhance priority riparian, wetland and upland areas within the headwaters of Hangman Creek and its tributaries in order to promote healthy self-sustaining fish and wildlife populations. A key goal of this project is the implementation of wildlife habitat protection efforts in a manner that also secures areas with the potential to provide stream and wetland habitats essential to native salmonid populations. This goal is critical in our efforts to address both resident fish and wildlife habitat needs in the Hangman Watershed. All

  13. Evaluation of Bull Trout Movements in the Tucannon and Lower Snake Rivers, 2002-2006 Project Completion Summary.

    Energy Technology Data Exchange (ETDEWEB)

    Faler, Michael P. [U.S. Fish and Wildlife Service; Mendel, Glen; Fulton, Carl [Washington Department of Fish and Wildlife


    The Columbia River Distinct Population Segment of bull trout (Salvelinus confluentus) was listed as threatened under the Endangered Species Act in 1998. One of the identified major threats to the species is fragmentation resulting from dams on over-wintering habitats of migratory subpopulations. A migratory subgroup in the Tucannon River appeared to utilize the Snake River reservoirs for adult rearing on a seasonal basis. As a result, a radio telemetry study was conducted on this subgroup from 2002-2006, to help meet Reasonable and Prudent Measures, and Conservation Recommendations associated with the lower Snake River dams in the FCRPS Biological Opinion, and to increase understanding of bull trout movements within the Tucannon River drainage. We sampled 1,109 bull trout in the Tucannon River; 124 of these were surgically implanted with radio tags and PIT tagged, and 681 were only PIT tagged. The remaining 304 fish were either recaptures, or released unmarked. Bull trout seasonal movements within the Tucannon River were similar to those described for other migratory bull trout populations. Bull trout migrated upstream in spring and early summer to the spawning areas in upper portions of the Tucannon River watershed. They quickly moved off the spawning areas in the fall, and either held or continued a slower migration downstream through the winter until early the following spring. During late fall and winter, bull trout were distributed in the lower half of the Tucannon River basin, down to and including the mainstem Snake River below Little Goose Dam. We were unable to adequately radio track bull trout in the Snake River and evaluate their movements or interactions with the federal hydroelectric dams for the following reasons: (1) none of our radio-tagged fish were detected attempting to pass a Snake River dam, (2) our radio tags had poor transmission capability at depths greater than 12.2 m, and (3) the sample size of fish that actually entered the Snake River

  14. Evaluate Bull Trout Movements in the Tucannon and Lower Snake Rivers, 2002-2003 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Faler, Michael P. (US Fish and Wildlife Service, Idaho Fishery Resource Office, Ahsahka, ID); Mendel, Glen W.; Fulton, Carl (Washington Department of Fish and Wildlife, Fish Management Division, Dayton, WA)


    We collected 279 adult bull trout (Salvelinus confluentus) in the Tucannon River during the Spring and Fall of 2003. Passive Integrated Transponder (PIT) tags were inserted in 191 of them, and we detected existing PIT tags in an additional 31bull trout. Thirty five of these were also surgically implanted with radio-tags, and we monitored the movements of these fish throughout the year. Fourteen radio-tags were recovered shortly after tagging, and as a result, 21 remained in the river through December 31, 2003. Four bull trout that were radio-tagged in spring 2002 were known to survive and carry their tags through the spring and/or summer of 2003. One of these fish spent the winter near river mile (RM) 13.0; the other 3 over-wintered in the vicinity of the Tucannon Hatchery between RM 34 and 36. Twenty-one radio tags from bull trout tagged in 2002 were recovered during the spring and summer, 2003. These tags became stationary the winter of 2002/2003, and were recovered between RM 11 and 55. We were unable to recover the remaining 15 tags from 2002. During the month of July, radio-tagged bull trout exhibited a general upstream movement into the upper reaches of the Tucannon subbasin. We observed some downstream movements of radio-tagged bull trout in mid to late September and throughout October. By late November and early December, radio tagged bull trout were relatively stationary, and were distributed from the headwaters downstream to river mile 6.4, near Lower Monumental Pool. As in 2002, we did not conduct work associated with objectives 2, 3, or 4 of this study, because we were unable to monitor migratory movement of radio-tagged bull trout into the Federal hydropower system on the mainstem Snake River. Transmission tests of submerged ATS model F1830 radio-tags in Lower Granite Pool showed that audible detection and individual tag identification was possible at depths of 20 and 30 ft. Tests were conducted using an ATS R-4000 Receiver equipped with an &apos

  15. Kootenai River Fisheries Investigations; Rainbow and Bull Trout Recruitment, 2003-2004 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Walters, Jody P.


    Rainbow trout Oncorhynchus mykiss provide the most important sport fishery in the Kootenai River, Idaho, but densities and catch rates are low. Low recruitment is one possible factor limiting the rainbow trout population. Bull trout Salvelinus confluentus also exist in the Kootenai River, but little is known about this population. Research reported here addresses the following objectives for the Kootenai River, Idaho: identify sources of rainbow and bull trout recruitment, monitor the rainbow trout population size structure to evaluate regulation changes initiated in 2002, and identify factors potentially limiting rainbow trout recruitment. A screw trap was used to estimate juvenile redband and bull trout out-migration from the Callahan Creek drainage, and electrofishing was conducted to estimate summer densities of bull trout rearing in the Idaho portion of the drainage. An estimated 1,132 juvenile redband trout and 68 juvenile bull trout out-migrated from Callahan Creek to the Kootenai River from April 7 through July 15, 2003. Densities of bull trout {ge} age-1 in North and South Callahan creeks ranged from 1.6 to 7.7 fish/100m{sup 2} in August. Bull trout redd surveys were conducted in North and South Callahan creeks, Boulder Creek, and Myrtle Creek. Thirty-two bull trout redds were located in North Callahan Creek, while 10 redds were found in South Callahan Creek. No redds were found in the other two streams. Modeling of culverts in the Deep Creek drainage identified two as upstream migration barriers, preventing rainbow trout from reaching spawning and rearing habitat. Water temperature monitoring in Deep Creek identified two sites where maximum temperatures exceeded those suitable for rainbow trout. Boulder Creek produces the most rainbow trout recruits to the Kootenai River in Idaho upstream of Deep Creek, but may be below carrying capacity for rearing rainbow trout due to nutrient limitations. Monthly water samples indicate Boulder Creek is nutrient limited

  16. Coeur d'Alene Tribe Fisheries Program Research, Monitoring and Evaluation Plan; Implementation of Fisheries Enhancement Opportunities on the Coeur d'Alene Reservation, 1997-2002 Technical Report.

    Energy Technology Data Exchange (ETDEWEB)

    Vitale, Angelo; Lamb, Dave; Peters, Ronald


    Westslope cutthroat trout (Oncorhynchus clarki lewisi) and bull trout (Salvelinus confluentus) are currently of special concern regionally and are important to the culture and subsistence needs of the Coeur d'Alene Tribe. The mission of the Coeur d'Alene Tribe Fisheries Program is to restore and maintain these native trout and the habitats that sustain them in order to provide subsistence harvest and recreational fishing opportunities for the Reservation community. The adfluvial life history strategy exhibited by westslope cutthroat and bull trout in the Lake Coeur d'Alene subbasin makes these fish susceptible to habitat degradation and competition in both lake and stream environments. Degraded habitat in Lake Coeur d'Alene and its associated streams and the introduction of exotic species has lead to the decline of westslope cutthroat and listing of bull trout under the endangered species act (Peters et al. 1998). Despite the effects of habitat degradation, several streams on the Reservation still maintain populations of westslope cutthroat trout, albeit in a suppressed condition (Table 1). The results of several early studies looking at fish population status and habitat condition on the Reservation (Graves et al. 1990; Lillengreen et al. 1993, 1996) lead the Tribe to aggressively pursue funding for habitat restoration under the Northwest Power Planning Council's (NWPPC) resident fish substitution program. Through these efforts, habitat restoration needs were identified and projects were initiated. The Coeur d'Alene Tribe Fisheries Program is currently involved in implementing stream habitat restoration projects, reducing the transport of sediment from upland sources, and monitoring fish populations in four watersheds on the Coeur d'Alene Reservation (Figure 1). Restoration projects have included riparian plantings, addition of large woody debris to streams, and complete channel reconstruction to restore historical natural

  17. Methow River Studies, Washington: abundance estimates from Beaver Creek and the Chewuch River screw trap, methodology testing in the Whitefish Island side channel, and survival and detection estimates from hatchery fish releases, 2013 (United States)

    Martens, Kyle D.; Fish, Teresa M.; Watson, Grace A.; Connolly, Patrick J.


    Salmon and steelhead populations have been severely depleted in the Columbia River from factors such as the presence of tributary dams, unscreened irrigation diversions, and habitat degradation from logging, mining, grazing, and others (Raymond, 1988). The U.S. Geological Survey (USGS) has been funded by the Bureau of Reclamation (Reclamation) to provide evaluation of on-going Reclamation funded efforts to recover Endangered Species Act (ESA) listed anadromous salmonid populations in the Methow River watershed, a watershed of the Columbia River in the Upper Columbia River Basin, in north-central Washington State (fig. 1). This monitoring and evaluation program was funded to document Reclamation’s effort to partially fulfill the 2008 Federal Columbia River Power System Biological Opinion (BiOp) (National Oceanographic and Atmospheric Administration, Fisheries Division 2003). This Biological Opinion includes Reasonable and Prudent Alternatives (RPA) to protect listed salmon and steelhead across their life cycle. Species of concern in the Methow River include Upper Columbia River (UCR) spring Chinook salmon (Oncorhynchus tshawytscha), UCR summer steelhead (O. mykiss), and bull trout (Salvelinus confluentus), which are all listed as threatened or endangered under the ESA. The work done by the USGS since 2004 has encompassed three phases of work. The first phase started in 2004 and continued through 2012. This first phase involved the evaluation of stream colonization and fish production in Beaver Creek following the modification of several water diversions (2000–2006) that were acting as barriers to upstream fish movement. Products to date from this work include: Ruttenburg (2007), Connolly and others (2008), Martens and Connolly (2008), Connolly (2010), Connolly and others (2010), Martens and Connolly (2010), Benjamin and others (2012), Romine and others (2013a), Weigel and others (2013a, 2013b, 2013c), and Martens and others (2014). The second phase, initiated in

  18. Evaluate Bull Trout Movements in the Tucannon and Lower Snake Rivers, 2004 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Faler, Michael P. (US Fish and Wildlife Service, Idaho Fishery Resource Office, Ahsahka, ID); Mendel, Glen W.; Fulton, Carl (Washington Department of Fish and Wildlife, Fish Management Division, Dayton, WA)


    We sampled and released 313 bull trout (Salvelinus confluentus) from the Tucannon River in 2004. Passive Integrated Transponder (PIT) tags were inserted in 231 of these individuals, and we detected existing PIT tags in an additional 44 bull trout. Twenty-five of these were also surgically implanted with radio-tags, and we monitored the movements of these fish throughout the year. Ten bull trout that were radio-tagged in 2003 were known to survive and carry their tags through the spring of 2004. One of these fish outmigrated into the Snake River in the fall, and remained undetected until February, when it's tag was located near the confluence of Alkali Flat Creek and the Snake River. The remaining 9 fish spent the winter between Tucannon River miles 2.1 (Powers Road) and 36.0 (Tucannon Fish Hatchery). Seven of these fish retained their tags through the summer, and migrated to known spawning habitat prior to September 2004. During June and July, radio-tagged bull trout again exhibited a general upstream movement into the upper reaches of the Tucannon subbasin. As in past years, we observed some downstream movements of radio-tagged bull trout in mid to late September and throughout October, suggesting post spawning outmigrations. By late November and early December, radio tagged bull trout were relatively stationary, and were distributed from river mile 42 at Camp Wooten downstream to river mile 17, near the Highway 12 bridge. As in previous years, we did not collect data associated with objectives 2, 3, or 4 of this study, because we were unable to monitor migratory movement of radio-tagged bull trout into the vicinity of the hydropower dams on the main stem Snake River. Transmission tests of submerged Lotek model NTC-6-2 nano-tags in Lower Granite Pool showed that audible detection and individual tag identification was possible at depths of 20, 30, and 40 ft. We were able to maintain tag detection and code separation at all depths from both a boat and 200 ft

  19. Acid rain publications by the U.S. Fish and Wildlife Service, 1979-1989 (United States)

    Villella, Rita F.


    Pollution of aquatic and terrestrial ecosystems has been a concern to society since the burning of fossil fuels began in the industrial revolution. In the past decade or so, this concern has been heightened by evidence that chemical transformation in the atmosphere of combustion by-products and subsequent long-range transport can cause environmental damage in remote areas. The extent of this damage and the rates of ecological recovery were largely unknown. "Acid rain" became the environmental issue of the 1980's. To address the increasing concerns of the public, in 1980 the Federal government initiated a 10-year interagency research program to develop information that could be used by the President and the Congress in making decisions for emission controls. The U.S. Fish and Wildlife Service has been an active participant in acid precipitation research. The Service provided support to a number of scientific conferences and forums, including the Action Seminar on Acid Precipitation held in Toronto, Canada, in 1979, an international symposium on Acidic Precipitation and Fishery Impacts in Northeastern North America in 1981, and a symposium on Acidic Precipitation and Atmospheric Deposition: A Western Perspective in 1982. These meetings as well as the growing involvement with the government's National Acidic Precipitation Assessment Program placed the Service in the lead in research on the biological effects of acidic deposition. Research projects have encompassed water chemistry, aquatic invertebrates, amphibians, fish, and waterfowl. Water quality surveys have been conducted to help determine the extent of acid precipitation effects in the northeast, Middle Atlantic, and Rocky Mountain regions. In addition to lake and stream studies, research in wetland and some terrestrial habitats has also been conducted. Specific projects have addressed important sport species such as brook trout (Salvelinus fontinalis), Atlantic salmon (Salmo salar), and striped bass (Morone

  20. Kootenay Lake Fertilization Experiment, Year 15 (North Arm) and Year 3 (South Arm) (2006) Report

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, E.U.; Sebastian, D.; Andrusak, G.F. [Fish and Wildlife Science and Allocation, Ministry of Environment, Province of British Columbia


    This report summarizes results from the fifteenth year (2006) of nutrient additions to the North Arm of Kootenay Lake and three years of nutrient additions to the South Arm. Experimental fertilization of the lake has been conducted using an adaptive management approach in an effort to restore lake productivity lost as a result of nutrient uptake in upstream reservoirs. The primary objective of the experiment is to restore kokanee (Oncorhynchus nerka) populations, which are the main food source for Gerrard rainbow trout (Oncorhynchus mykiss) and bull trout (Salvelinus confluentus). The quantity of agricultural grade liquid fertilizer (10-34-0, ammonium polyphosphate and 28-0-0, urea ammonium nitrate) added to the North Arm in 2006 was 44.7 tonnes of P and 248.4 tonnes of N. The total fertilizer load added to the South Arm was 257 tonnes of nitrogen; no P was added. Kootenay Lake has an area of 395 km{sup 2}, a maximum depth of 150 m, a mean depth of 94 m, and a water renewal time of approximately two years. Kootenay Lake is a monomictic lake, generally mixing from late fall to early spring and stratifying during the summer. Surface water temperatures generally exceed 20 C for only a few weeks in July. Results of oxygen profiles were similar to previous years with the lake being well oxygenated from the surface to the bottom depths at all stations. Similar to past years, Secchi disc measurements at all stations in 2006 indicate a typical seasonal pattern of decreasing depths associated with the spring phytoplankton bloom, followed by increasing depths as the bloom gradually decreases by the late summer and fall. Total phosphorus (TP) ranged from 2-7 {micro}g/L and tended to decrease as summer advanced. Over the sampling season dissolved inorganic nitrogen (DIN) concentrations decreased, with the decline corresponding to nitrate (the dominant component of DIN) being utilized by phytoplankton during summer stratification. Owing to the importance of epilimnetic nitrate

  1. Assessment of Salmonids and Their Habitat Conditions in the Walla Walla River Basin within Washington, Annual Report 2002-2003.

    Energy Technology Data Exchange (ETDEWEB)

    Mendel, Glen; Trump, Jeremy; Gembala, Mike


    This study began in 1998 to assess salmonid distribution, relative abundance, genetics, and the condition of salmonid habitats in the Walla Walla River basin. Stream flows in the Walla Walla Basin continue to show a general trend that begins with a sharp decline in discharge in late June, followed by low summer flows and then an increase in discharge in fall and winter. Manual stream flow measurements at Pepper bridge showed an increase in 2002 of 110-185% from July-September, over flows from 2001. This increase is apparently associated with a 2000 settlement agreement between the U.S. Fish and Wildlife Service (USFWS) and the irrigation districts to leave minimum flows in the river. Stream temperatures in the Walla Walla basin were similar to those in 2001. Upper montane tributaries maintained maximum summer temperatures below 65 F, while sites in mid and lower Touchet and Walla Walla rivers frequently had daily maximum temperatures well above 68 F (high enough to inhibit migration in adult and juvenile salmonids, and to sharply reduce survival of their embryos and fry). These high temperatures are possibly the most critical physiological barrier to salmonids in the Walla Walla basin, but other factors (available water, turbidity or sediment deposition, cover, lack of pools, etc.) also play a part in salmonid survival, migration, and breeding success. The increased flows in the Walla Walla, due to the 2000 settlement agreement, have not shown consistent improvements to stream temperatures. Rainbow/steelhead (Oncorhynchus mykiss) trout represent the most common salmonid in the basin. Densities of Rainbow/steelhead in the Walla Walla River from the Washington/Oregon stateline to Mojonnier Rd. dropped slightly from 2001, but are still considerably higher than before the 2000 settlement agreement. Other salmonids including; bull trout (Salvelinus confluentus), chinook salmon (Oncorhynchus tshawytscha), mountain whitefish (Prosopium williamsoni), and brown trout (Salmo

  2. Implementation of Fisheries Enhancement Opportunities on the Coeur d'Alene Reservation; Coeur d'Alene Tribe Fish, Water, and Wildlife Program, REVISED 2002 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Vitale, Angelo; Lamb, Dave; Scott, Jason


    Historically, the Coeur d'Alene Indian Tribe depended on runs of anadromous salmon and steelhead along the Spokane River and Hangman Creek, as well as resident and adfluvial forms of trout and char in Coeur d'Alene Lake, for survival. Dams constructed in the early 1900s on the Spokane River in the City of Spokane and at Little Falls (further downstream) were the first dams that initially cut-off the anadromous fish runs from the Coeur d'Alene Tribe. These fisheries were further removed by the construction of Chief Joseph and Grand Coulee Dams on the Columbia River. Together, these actions forced the Tribe to rely solely on the resident fish resources of Coeur d'Alene Lake (Staff Communication). The Coeur d'Alene Tribe is estimated to have historically harvested around 42,000 westslope cutthroat trout (Oncorhynchus clarki) per year (Scholz et al. 1985). In 1967, Mallet (1969) reported that 3,329 cutthroat were harvested from the St. Joe River, and a catch of 887 was reported from Coeur d'Alene Lake. This catch is far less than the 42,000 fish per year the tribe harvested historically. Today, only limited opportunities exist to harvest cutthroat trout in the Coeur d'Alene Basin. The declines in native salmonid fish populations, particularly cutthroat and bull trout (Salvelinus confluentus), in the Coeur d'Alene basin have been the focus of study by the Coeur d' Alene Tribe's Fisheries and Water Resources programs since 1990. It appears that there are a number of factors contributing to the decline of resident salmonid stocks within Coeur d'Alene Lake and its tributaries (Ellis 1932; Oien 1957; Mallet 1969; Scholz et. al. 1985, Lillengreen et. al. 1993). These factors include: construction of Post Falls Dam in 1906; major changes in land cover types, agricultural activities and introduction of exotic fish species. Over 100 years of mining activities in the Coeur d'Alene River drainage have had devastating

  3. Implementation of Fisheries Enhancement Opportunities on the Coeur d'Alene Reservation, 2002 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Vitale, Angelo, Lamb, Dave; Scott, Jason


    Historically, the Coeur d'Alene Indian Tribe depended on runs of anadromous salmon and steelhead along the Spokane River and Hangman Creek, as well as resident and adfluvial forms of trout and char in Coeur d'Alene Lake, for survival. Dams constructed in the early 1900s on the Spokane River in the City of Spokane and at Little Falls (further downstream) were the first dams that initially cut-off the anadromous fish runs from the Coeur d'Alene Tribe. These fisheries were further removed by the construction of Chief Joseph and Grand Coulee Dams on the Columbia River. Together, these actions forced the Tribe to rely solely on the resident fish resources of Coeur d'Alene Lake (Staff Communication). The Coeur d'Alene Tribe is estimated to have historically harvested around 42,000 westslope cutthroat trout (Oncorhynchus clarki) per year (Scholz et al. 1985). In 1967, Mallet (1969) reported that 3,329 cutthroat were harvested from the St. Joe River, and a catch of 887 was reported from Coeur d'Alene Lake. This catch is far less than the 42,000 fish per year the tribe harvested historically. Today, only limited opportunities exist to harvest cutthroat trout in the Coeur d'Alene Basin. The declines in native salmonid fish populations, particularly cutthroat and bull trout (Salvelinus confluentus), in the Coeur d'Alene basin have been the focus of study by the Coeur d' Alene Tribe's Fisheries and Water Resources programs since 1990. It appears that there are a number of factors contributing to the decline of resident salmonid stocks within Coeur d'Alene Lake and its tributaries (Ellis 1932; Oien 1957; Mallet 1969; Scholz et. al. 1985, Lillengreen et. al. 1993). These factors include: construction of Post Falls Dam in 1906; major changes in land cover types, agricultural activities and introduction of exotic fish species. Over 100 years of mining activities in the Coeur d'Alene River drainage have had devastating

  4. Aquatic biological communities and associated habitats at selected sites in the Big Wood River Watershed, south-central Idaho, 2014 (United States)

    MacCoy, Dorene E.; Short, Terry M.


    limited at BW Stanton, where shallow-water habitat conditions prevailed.Macroinvertebrate community diversity was high at all sites except for BW Stanton, where low community diversity was attributed to low species richness and high abundances of a few tolerant taxa. Presence of low species diversity and high macroinvertebrate tolerance values at BW Stanton indicates that benthic community condition and stream health were reduced at that location.Fish surveys done in September 2014 did not indicate any significant reductions in native fish communities in the Big Wood River or its tributaries. Native rainbow trout (Oncorhynchus mykiss) and Wood River sculpin (Cottus leiopomus) were the dominant fish species in the drainage and were found at all tributary and main-stem sites. Non-native brown (Salmo trutta) and brook trout (Salvelinus fontinalis) were limited to lower drainage sites on the Big Wood River (BW Hailey and BW Stanton), and occurred in relatively low numbers.

  5. Methow River Studies, Washington: abundance estimates from Beaver Creek and the Chewuch River screw trap, methodology testing in the Whitefish Island side channel, and survival and detection estimates from hatchery fish releases, 2013 (United States)

    Martens, Kyle D.; Fish, Teresa M.; Watson, Grace A.; Connolly, Patrick J.


    Salmon and steelhead populations have been severely depleted in the Columbia River from factors such as the presence of tributary dams, unscreened irrigation diversions, and habitat degradation from logging, mining, grazing, and others (Raymond, 1988). The U.S. Geological Survey (USGS) has been funded by the Bureau of Reclamation (Reclamation) to provide evaluation of on-going Reclamation funded efforts to recover Endangered Species Act (ESA) listed anadromous salmonid populations in the Methow River watershed, a watershed of the Columbia River in the Upper Columbia River Basin, in north-central Washington State (fig. 1). This monitoring and evaluation program was funded to document Reclamation’s effort to partially fulfill the 2008 Federal Columbia River Power System Biological Opinion (BiOp) (National Oceanographic and Atmospheric Administration, Fisheries Division 2003). This Biological Opinion includes Reasonable and Prudent Alternatives (RPA) to protect listed salmon and steelhead across their life cycle. Species of concern in the Methow River include Upper Columbia River (UCR) spring Chinook salmon (Oncorhynchus tshawytscha), UCR summer steelhead (O. mykiss), and bull trout (Salvelinus confluentus), which are all listed as threatened or endangered under the ESA. The work done by the USGS since 2004 has encompassed three phases of work. The first phase started in 2004 and continued through 2012. This first phase involved the evaluation of stream colonization and fish production in Beaver Creek following the modification of several water diversions (2000–2006) that were acting as barriers to upstream fish movement. Products to date from this work include: Ruttenburg (2007), Connolly and others (2008), Martens and Connolly (2008), Connolly (2010), Connolly and others (2010), Martens and Connolly (2010), Benjamin and others (2012), Romine and others (2013a), Weigel and others (2013a, 2013b, 2013c), and Martens and others (2014). The second phase, initiated in

  6. Kootenay Lake Fertilization Experiment, Year 15 (North Arm) and Year 3 (South Arm) (2006) Report

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, E.U.; Sebastian, D.; Andrusak, G.F. [Fish and Wildlife Science and Allocation, Ministry of Environment, Province of British Columbia


    This report summarizes results from the fifteenth year (2006) of nutrient additions to the North Arm of Kootenay Lake and three years of nutrient additions to the South Arm. Experimental fertilization of the lake has been conducted using an adaptive management approach in an effort to restore lake productivity lost as a result of nutrient uptake in upstream reservoirs. The primary objective of the experiment is to restore kokanee (Oncorhynchus nerka) populations, which are the main food source for Gerrard rainbow trout (Oncorhynchus mykiss) and bull trout (Salvelinus confluentus). The quantity of agricultural grade liquid fertilizer (10-34-0, ammonium polyphosphate and 28-0-0, urea ammonium nitrate) added to the North Arm in 2006 was 44.7 tonnes of P and 248.4 tonnes of N. The total fertilizer load added to the South Arm was 257 tonnes of nitrogen; no P was added. Kootenay Lake has an area of 395 km{sup 2}, a maximum depth of 150 m, a mean depth of 94 m, and a water renewal time of approximately two years. Kootenay Lake is a monomictic lake, generally mixing from late fall to early spring and stratifying during the summer. Surface water temperatures generally exceed 20 C for only a few weeks in July. Results of oxygen profiles were similar to previous years with the lake being well oxygenated from the surface to the bottom depths at all stations. Similar to past years, Secchi disc measurements at all stations in 2006 indicate a typical seasonal pattern of decreasing depths associated with the spring phytoplankton bloom, followed by increasing depths as the bloom gradually decreases by the late summer and fall. Total phosphorus (TP) ranged from 2-7 {micro}g/L and tended to decrease as summer advanced. Over the sampling season dissolved inorganic nitrogen (DIN) concentrations decreased, with the decline corresponding to nitrate (the dominant component of DIN) being utilized by phytoplankton during summer stratification. Owing to the importance of epilimnetic nitrate

  7. Kokanee Stocking and Monitoring, Flathead Lake, 1993-1994 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Deleray, Mark (Montana Department of Fish, Wildlife and Parks, Kalispell, MT); Fredenberg, Wade (US Fish and Wildlife Service, Bozeman, MT); Hansen, Barry (Confederated Salish and Kootenai Tribes of the Flathead Nation, Pablo, MT)


    One mitigation goal of the Hungry Horse Dam fisheries mitigation program, funded by the Bonneville Power Administration, is to replace lost production of 100,000 adult kokanee in Flathead Lake. The mitigation program calls for a five-year test to determine if kokanee can be reestablished in Flathead Lake. The test consists. of annual stocking of one million hatchery-raised yearling kokanee. There are three benchmarks for judging the success of the kokanee reintroduction effort: (1) Post-stocking survival of 30 percent of planted kokanee one year after stocking; (2) Yearling to adult survival of 10 percent (100,000 adult salmon); (3) Annual kokanee harvest of 50,000 or more fish per year by 1998, with an average length of 11 inches or longer for harvested fish, and fishing pressure of 100,000 angler hours or more. Kokanee were the primary sport fish species in the Flathead Lake fishery in the early 1900s, and up until the late 1980s when the population rapidly declined in numbers and then disappeared. Factors identified which influenced the decline of kokanee are the introduction of opossum shrimp (Mysis relicta), hydroelectric operations, overharvest through angling, and competition and/or predation by lake trout (Salvelinus namaycush) and lake whitefish (Coregonur clupeaformis). The purpose of this report was to summarize the stocking program and present monitoring results from the 1993 and 1994 field seasons. In June 1993, roughly 210,000 yearling kokanee were stocked into two bays on the east shore of Flathead Lake. Following stocking, we observed a high incidence of stocked kokanee in stomach samples from lake trout captured in areas adjacent to the stocking sites and a high percentage of captured lake trout containing kokanee. Subsequent monitoring concluded that excessive lake trout predation precluded significant survival of kokanee stocked in 1993. In June 1994, over 802,000 kokanee were stocked into Big Arm Bay. The combination of near optimum water

  8. The potential influence of changing climate on the persistence of salmonids of the inland west (United States)

    Haak, A.L.; Williams, J.E.; Isaak, D.; Todd, A.; Muhlfeld, C.C.; Kershner, J.L.; Gresswell, R.E.; Hostetler, S.W.; Neville, H.M.


    , 2007), a warming climate may gradually increase the quality and extent of suitable habitat. Over time, previously constrained populations are expected to expand into these new habitats and increase in number. Some evidence suggests this may already be happening in Alaska, where streams in recently deglaciated areas are being colonized by emigrants from nearby salmon and char populations (Milner and others, 2000). Unfortunately, many of the sensitive salmonid species that are often the focus of western managers are unlikely to benefit from future water temperature increases. Warmer stream temperatures will facilitate invasion by nonnative species that are broadly established in downstream areas into upstream areas where they will compete with native species (Rieman and others, 2006; Rahel and Olden, 2008; Fausch and others, 2009). In other cases, warmer stream temperatures will render thermally suitable habitats unsuitable in downstream areas and effect net losses of habitat because upstream distributions are often constrained by streams that are too small or steep (Hari and others, 2006; Isaak and others, 2010). Both scenarios are realistic for fish species like bull trout (Salvelinus confluentus) (Rieman and others, 2006; Rieman and others, 2007), the various subspecies of cutthroat trout (Oncorhynchus clarkii) (Williams and others, 2009), Gila trout (Oncorhynchus gilae gilae) (Kennedy and others, 2008), and Apache trout (Oncorhynchus gilae apache) (Rinne and Minckley, 1985; Carmichael and others, 1993). As native species are increasingly confined to smaller and more isolated habitats by a gradually warming climate, the effects of wildfires (whether related to lethal changes in water quality during a fire, channel debris flows, or chronic postfire warming ) could have greater proportional effects on remaining habitats (for example, Brown and others, 2001; Rieman and others, 2007). If these changes were accompanied by additional hydrologic alterations associated with