WorldWideScience

Sample records for charr salvelinus fontinalis

  1. Behavioural thermoregulatory tactics in lacustrine brook charr, Salvelinus fontinalis.

    Directory of Open Access Journals (Sweden)

    Andrea Bertolo

    Full Text Available The need to vary body temperature to optimize physiological processes can lead to thermoregulatory behaviours, particularly in ectotherms. Despite some evidence of within-population phenotypic variation in thermal behaviour, the occurrence of alternative tactics of this behaviour is rarely explicitly considered when studying natural populations. The main objective of this study was to determine whether different thermal tactics exist among individuals of the same population. We studied the behavioural thermoregulation of 33 adult brook charr in a stratified lake using thermo-sensitive radio transmitters that measured hourly individual temperature over one month. The observed behavioural thermoregulatory patterns were consistent between years and suggest the existence of four tactics: two "warm" tactics with both crepuscular and finer periodicities, with or without a diel periodicity, and two "cool" tactics, with or without a diel periodicity. Telemetry data support the above findings by showing that the different tactics are associated with different patterns of diel horizontal movements. Taken together, our results show a clear spatio-temporal segregation of individuals displaying different tactics, suggesting a reduction of niche overlap. To our knowledge, this is the first study showing the presence of behavioural thermoregulatory tactics in a vertebrate.

  2. Heritability of life-history tactics and genetic correlation with body size in a natural population of brook charr (Salvelinus fontinalis).

    Science.gov (United States)

    Thériault, V; Garant, D; Bernatchez, L; Dodson, J J

    2007-11-01

    A common dimorphism in life-history tactic in salmonids is the presence of an anadromous pathway involving a migration to sea followed by a freshwater reproduction, along with an entirely freshwater resident tactic. Although common, the genetic and environmental influence on the adoption of a particular life-history tactic has rarely been studied under natural conditions. Here, we used sibship-reconstruction based on microsatellite data and an 'animal model' approach to estimate the additive genetic basis of the life-history tactic adopted (anadromy vs. residency) in a natural population of brook charr, Salvelinus fontinalis. We also assess its genetic correlation with phenotypic correlated traits, body size and body shape. Significant heritability was observed for life-history tactic (varying from 0.52 to 0.56 depending on the pedigree scenario adopted) as well as for body size (from 0.44 to 0.50). There was also a significant genetic correlation between these two traits, whereby anadromous fish were genetically associated with bigger size at age 1 (r(G) = -0.52 and -0.61). Our findings thus indicate that life-history tactics in this population have the potential to evolve in response to selection acting on the tactic itself or indirectly via selection on body size. This study is one of the very few to have successfully used sibship-reconstruction to estimate quantitative genetic parameters under wild conditions. PMID:17956389

  3. Ecological diversity in the polymorphic fish Arctic charr (Salvelinus alpinus)

    OpenAIRE

    Woods, Pamela J., 1979-

    2011-01-01

    The Arctic charr Salvelinus alpinus is extremely diverse and its differentiation may indicate ecological speciation. This dissertation aims to compare trends in ecological diversity across broad geographical regions and place it within an ecosystem context by comparing study systems in Iceland and Alaska. In the first chapter, gut contents of Arctic charr across ~50 lakes in Iceland were analyzed to form 6 habitat-associated prey categories. Consumption of zooplankton was related to high sili...

  4. Induction and viability of tetraploids in brook trout (Salvelinus fontinalis)

    Science.gov (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 ...

  5. Behaviour, physiology and carotenoid pigmentation in Arctic charr Salvelinus alpinus

    OpenAIRE

    Brännäs, Eva; Nilsson, Jan; Magnhagen, Carin; Backström, Tobias

    2014-01-01

    The behaviour during an exploration task and the response to a confinement stress of Arctic charr Salvelinus alpinus were evaluated. Behaviour of individuals during 90 min of exploration was classified into high and low activity. High-activity individuals had higher plasma cortisol levels following stress compared to low-activity individuals. This indicates that high- and low-activity individuals correspond to reactive and proactive stress-coping styles. Further, a pigmentation analysis showe...

  6. Landlocked Arctic charr ( Salvelinus alpinus ) population structure and lake morphometry in Greenland - is there a connection?

    DEFF Research Database (Denmark)

    Riget, F.; Jeppesen, E.; Landkildehus, F.;

    2000-01-01

    Landlocked Arctic charr (Salvelinus alphinus) populations in sub-Arctic and Arctic Greenland lakes were sampled with multi- mesh-sized survey gillnets. The study covered a range of small shallow lakes (0.01 km(2) maximum depth 200 In). Arctic charr were found in one to three different forms in la...

  7. Landlocked Arctic charr ( Salvelinus alpinus ) population structure and lake morphometry in Greenland - is there a connection?

    DEFF Research Database (Denmark)

    Riget, F.; Jeppesen, E.; Landkildehus, F.; Lauridsen, T.L.; Geertz-Hansen, Peter; Christoffersen, K.; Sparholt, H.

    2000-01-01

    Landlocked Arctic charr (Salvelinus alphinus) populations in sub-Arctic and Arctic Greenland lakes were sampled with multi- mesh-sized survey gillnets. The study covered a range of small shallow lakes (0.01 km(2) maximum depth 200 In). Arctic charr were found in one to three different forms in...... lakes with maximum depths >3 m. A dwarf form occurred in all lakes inhabited by Arctic charr and was the only form in lakes with maximum depths 20 m, large-sized charr were more abundant, and the length- frequency distribution of the population was bimodal, with a first mode around 10-12 cm and a second...... mode around 2637 cm. In a single large and deep lake, a distinct medium-sized pelagic zooplankton-eating charr form occurred. Maximum size of individual charr was significantly positively correlated with lake maximum depth and volume, and the mean size of large-sized charr was significantly positively...

  8. Radiocaesium turnover in Arctic charr (Salvelinus alpinus) and brown trout (Salmo trutta) in a Norwegian lake

    International Nuclear Information System (INIS)

    The radioactivity of brown trout (Salmo trutta L.) and Arctic charr (Salvelinus alpinus (L.)) was monitored in a Norwegian lake from 1986 to 1989. A distinct difference was observed between brown trout and Arctic charr in the accumulation of radiocaesium (134Cs and 137Cs) from the Chernobyl fallout, and the study focused on the understanding of this difference. Brown trout had a large food consumption and a corresponding high intake of radiocaesium. Excretion was 20% faster in brown trout than Arctic charr as brown trout lived at high temperatures in epilimnic water. Arctic charr had a lower food consumption (less than one-third of trout) and lived in colder meta-and hypolimnic water. Arctic charr therefore had a lower intake and slower excretion of radiocaesium. Brown trout an Arctic charr had different diets. For brown trout zoobenthos was the dominant food item, whereas Artic charr mainly fed on zooplankton. The radioactivity in the stomach contents of the two species was different in 1986, but similar for the rest of the period. Higher levels of radiocaesium in brown trout than Arctic charr in 1986 were due to a higher food consumption and more radioactive food items in its diet. The parallel development in accumulated radiocaesium through summer 1987 was probably formed by brown trout balancing a higher intake with a faster excretion. The ecological half-lives of radiocaesium in brown trout (357 days) and Arctic charr (550 days) from Lake Hoeysjoeen indicated a slow removal of the isotopes from the food webs. (author)

  9. 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.

    2003-01-01

    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

  10. Morphological divergence in a trimorphic population of Arctic charr (Salvelinus alpinus (L.)) in Skogsfjordvatn, northern Norway.

    OpenAIRE

    Skoglund, Sigrid Østrem

    2013-01-01

    Sympatric polymorphisms are found in many freshwater fish taxa, including the salmonid Arctic charr (Salvelinus alpinus (L.)). Polymorphism is often expressed as differences in morphology, behaviour and life-history strategies, and may be driven by alternative phenotypic adaptations to resource use such as habitat and prey preferences. Morphological divergence is usually linked to different functions of the morphological trait. Here, I study the correlations between morphology and ecological ...

  11. Concomitant Antibiotic and Mercury Resistance Among Gastrointestinal Microflora of Feral Brook Trout, Salvelinus fontinalis

    OpenAIRE

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

    2012-01-01

    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 concentrat...

  12. The pineal gland of Arctic charr (Salvelinus alpinus L.): a survey of seasonal melatonin production and gland ultrastructure

    OpenAIRE

    Musæus, Fredrikke Johansen

    2009-01-01

    The pineal gland is part of the endocrine system involved with rhythmic activity in e.g. fish. The main product of the pineal gland is the indole hormone melatonin, synthesised from the amino acid tryptophan. Melatonin is mainly synthesized when it is dark, as light inhibit the production. For this reason melatonin is thought to be strongly involved in biological rhythms. Arctic charr (Salvelinus alpinus) is a circumpolar species and anadromous in parts of its distribution area. Arctic charr ...

  13. Cytogenetic and histological studies of the brook trout (Salvelinus fontinalis) x arctic charr (Salvelinus alpinus) hybrids

    OpenAIRE

    Lisboa, Rodrigo

    2012-01-01

    In aquaculture, application of fish hybrids has increased. This technique permits improvement of the fish production by providing specimens showing better growth rate when compared to the parental species. Indeed, sterile individuals are highly demanded because quite frequently parental fish mature before they reach the market size, which impairs their growth and decrease their economic value. Throughout the last years, the commercial and scientific interest in salmonids has increased rapidly...

  14. Area use of Arctic charr (Salvelinus alpinus) and brown trout (Salmo trutta) in an Arctic fjord system - a two year acoustic telemetry study

    OpenAIRE

    Kirkemoen, Odin Lagerborg

    2016-01-01

    The Arctic charr Salvelinus alpinus (L.) and the brown trout Salmo trutta L. are fish species with complex and comparable life strategies. However, there are also differences between the two species. The migratory behavior of Arctic charr and brown trout at sea is poorly understood compared to their far more studied behavior in fresh water. Because of the declining populations of anadromous Arctic charr the last decades, this species is particularly important to understand in order to mitigat...

  15. Land-locked Arctic charr (Salvelinus alpinus) population structure and lake morphometry in Greenland - is there a connection?

    DEFF Research Database (Denmark)

    Riget, F.; Jeppesen, E.; Landkildehus, F.;

    2000-01-01

    Landlocked Arctic charr (Salvelinus alpinus) populations in sub-Arctic and Arctic Greenland lakes were sampled with multi-mesh-sized survey gillnets. The study covered a range of small shallow lakes (0.01 km2, maximum depth <3.3 m) to large deep lakes (43 km2, maximum depth >200 m). Arctic charr ...

  16. Growth and fatty acid composition of two strains of Arctic charr (Salvelinus alpinus) on diets formulated with low fish oil inclusion in a recirculating aquaculture system

    Science.gov (United States)

    Arctic charr (Salvelinus alpinus) is a highly desirable species to culture due to their fast growth, culture conditions and reputation as a sustainably produced fish due to closed containment culture. A study was conducted to evaluate two Arctic charr stocks (one commercial stock and one from the ...

  17. Life history strategies of a trimorphic population of Arctic charr (Salvelinus alpinus (L.)) in Skogsfjordvatn, northern-Norway

    OpenAIRE

    Smalås, Aslak

    2013-01-01

    Polymorphisms are widespread throughout many different taxa of vertebrates. Discrete polymorphisms or morphs usually differentiate in morphology, ecology and life history, most likely driven by adaptations to different habitats and resources. For sympatric morphs to be able to maximize fitness in different niches and habitats, they may develop differences in several life history traits. Arctic charr (Salvelinus alpinus (L.)) is a good model species for verifying and understanding ecological d...

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

    Science.gov (United States)

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

    2016-01-01

    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.

  19. Genetic Variability and Structuring of Arctic Charr (Salvelinus alpinus Populations in Northern Fennoscandia.

    Directory of Open Access Journals (Sweden)

    Takahito Shikano

    Full Text Available Variation in presumably neutral genetic markers can inform us about evolvability, historical effective population sizes and phylogeographic history of contemporary populations. We studied genetic variability in 15 microsatellite loci in six native landlocked Arctic charr (Salvelinus alpinus populations in northern Fennoscandia, where this species is considered near threatened. We discovered that all populations were genetically highly (mean FST ≈ 0.26 differentiated and isolated from each other. Evidence was found for historical, but not for recent population size bottlenecks. Estimates of contemporary effective population size (Ne ranged from seven to 228 and were significantly correlated with those of historical Ne but not with lake size. A census size (NC was estimated to be approximately 300 individuals in a pond (0.14 ha, which exhibited the smallest Ne (i.e. Ne/NC = 0.02. Genetic variability in this pond and a connected lake is severely reduced, and both genetic and empirical estimates of migration rates indicate a lack of gene flow between them. Hence, albeit currently thriving, some northern Fennoscandian populations appear to be vulnerable to further loss of genetic variability and are likely to have limited capacity to adapt if selection pressures change.

  20. Temporal changes in daily food intake of Arctic charr, Salvelinus alpinus L., of different sizes monitored by radiography

    International Nuclear Information System (INIS)

    Temporal variations in food consumption of three year classes of Arctic charr, Salvelinus alpinus, held under conditions of constant temperature ( 10 °C) and continuous artificial illumination were studied by monitoring daily food intake at different times of the year. Food was supplied continuously in excess and consumption was determined using X-radiography. There were found to be seasonal differences in the amounts of food consumed, with food intake being lowest during the autumn. Attempts were made to relate these changes to patterns of sexual maturation, but results were equivocal and further study is required in order to isolate the factors responsible for variations observed

  1. Impacts of a gape limited Brook Trout, Salvelinus fontinalis, on larval Northwestern salamander, Ambystoma gracile, growth: A field enclosure experiment

    Science.gov (United States)

    Currens, C.R.; Liss, W.J.; Hoffman, R.L.

    2007-01-01

    The formation of amphibian population structure is directly affected by predation. Although aquatic predators have been shown to have direct negative effects on larval salamanders in laboratory and field experiments, the potential impacts of gape-limited fish on larval salamander growth has been largely underexplored. We designed an enclosure experiment conducted in situ to quantify the effects of gape-limited Brook Trout (Salvelinus fontinalis) on larval Northwestern Salamander (Ambystoma gracile) growth. We specifically tested whether the presence of fish too small to consume larvae had a negative effect on larval growth. The results of this study indicate that the presence of a gape-limited S. fontinalis can have a negative effect on growth of larval A. gracile salamanders. Copyright 2007 Society for the Study of Amphibians and Reptiles.

  2. Hybridization between native white-spotted charr and nonnative brook trout in the upper Sorachi River, Hokkaido, Japan

    OpenAIRE

    Kitano, Satoshi; Ohdachi, Satoshi; Koizumi, Itsuro; Hasegawa, Koh

    2013-01-01

    Invasion status and impacts of nonnative brook trout (Salvelinus fontinalis) in a Hokkaido stream were investigated with field surveys and genetic analyses. Nonnative brook trout was detected in nine (41 %) of the 22 sampled reaches in three tributaries of the Sorachi River, Hokkaido, Japan. Based on the external pigmentation, twelve putative hybrids between brook trout and native white-spotted charr (Salvelinus leucomaenis) were collected in two reaches. Microsatellite and mitochondrial DNA ...

  3. Spatial and temporal movement dynamics of brook Salvelinus fontinalis and brown trout Salmo trutta

    Science.gov (United States)

    Davis, L.A.; Wagner, Tyler; Barton, Meredith L.

    2015-01-01

    Native eastern brook trout Salvelinus fontinalis and naturalized brown trout Salmo trutta occur sympatrically in many streams across the brook trout’s native range in the eastern United States. Understanding within- among-species variability in movement, including correlates of movement, has implications for management and conservation. We radio tracked 55 brook trout and 45 brown trout in five streams in a north-central Pennsylvania, USA watershed to quantify the movement of brook trout and brown trout during the fall and early winter to (1) evaluate the late-summer, early winter movement patterns of brook trout and brown trout, (2) determine correlates of movement and if movement patterns varied between brook trout and brown trout, and (3) evaluate genetic diversity of brook trout within and among study streams, and relate findings to telemetry-based observations of movement. Average total movement was greater for brown trout (mean ± SD = 2,924 ± 4,187 m) than for brook trout (mean ± SD = 1,769 ± 2,194 m). Although there was a large amount of among-fish variability in the movement of both species, the majority of movement coincided with the onset of the spawning season, and a threshold effect was detected between stream flow and movement: where movement increased abruptly for both species during positive flow events. Microsatellite analysis of brook trout revealed consistent findings to those found using radio-tracking, indicating a moderate to high degree of gene flow among brook trout populations. Seasonal movement patterns and the potential for relatively large movements of brook and brown trout highlight the importance of considering stream connectivity when restoring and protecting fish populations and their habitats.

  4. Histology and DNA cytophotometry of the pancreas of acid exposed brook trout (Salvelinus fontinalis)

    Energy Technology Data Exchange (ETDEWEB)

    Mudge, J.E.

    1970-01-01

    The gross anatomy and histology of the pancreas were studied in untreated and acid exposed brook trout (Salvelinus fontinalis). Also, three fixatives (4% formalin, Zenker-formol, and Bouin's) and four staining procedures (hematoxylin and eosin, phloxine-methylene blue, Mallory-Heidenhain's azan, and chromium-hematoxylin-phloxine) were evaluated in terms of their utility for histological studies of the brook trout pancreas. Finally, the exocrine cells of control and acid exposed trout were examined cytophotometrically to determine feulgen DNA content. Briefly, the major findings were as follows: although pancreatic tissue in the brook trout is diffusely scattered among the pyloric caeca and mesenteries bordering hepatic, splenic and small intestinal areas, and bulk of the gland resides next to the pyloric stomach and its entrance into the small intestine; pancreatic islets are also most numerous and best developed in this region; endocrine islets are composed of two granular cell types: Basophilic beta cells which comprise more than 70% of the islet and alpha cells which are scattered singly throughout each islet; histochemical analysis of F-DNA content of exocrine pancreas under control and experimental conditions indicates that these cells were not influenced by acute acid exposure; no histopathological changes were found in either endocrine or exocrine cells which could be attributed to prior exposure of trout to acid pH; and Mallory-Heidenhain's azan staining of Zenker-formol fixed tissue specimens proved to be an excellent stain for histological studies of both endocrine and exocrine components of the trout pancreas.

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

    Science.gov (United States)

    Striberny, Anja; Ravuri, Chandra Sekhar; Jobling, Malcolm; Jørgensen, Even Hjalmar

    2015-01-01

    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. PMID:26421838

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

    Directory of Open Access Journals (Sweden)

    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. Arctic charr (Salvelinus alpinus squeezed in a complex fish community dominated by perch (Perca fluviatilis

    Directory of Open Access Journals (Sweden)

    Odd Terje Sandlund

    2013-12-01

    Full Text Available In the complex fish community of Lake Skasen, southeastern Norway, the relative population density, habitat use and diet of Arctic charr, perch, roach and burbot was studied by a gill net survey during June-September 2010. A marked segregation in habitat use was observed, with Arctic charr and burbot captured in the profundal and deepest part of the pelagic habitat, and perch and roach captured in the littoral and upper part of the pelagic. Perch dominated the total catches, followed by roach. Arctic charr occurred in low numbers in the catches, and also had a low annual growth rate. Even in June, at low water temperatures, Arctic charr were confined to the profundal. Both Arctic charr, roach and perch fed on the same cladocerans, but all size groups of perch had fish as an important part of the diet. Analysis of stable carbon and nitrogen isotopes revealed a narrow trophic niche of Arctic charr, positioned at the extreme pelagic end of the carbon gradient relative to the other fish species. These had a wider span of δ13C signatures, but more positioned towards the littoral end of the carbon gradient. The low growth rate of Arctic charr, despite a low population density, indicates that food is a limiting resource for charr in this lake, probably due to a confinement to the profundal habitat as a result of competition and predator avoidance. Since all age-classes of Arctic charr seem to be enclosed in the profundalhabitat, intraspecific competition and predation may be supplementary stressors resulting in low annual recruitment and low population density, as well as low individual growth rate, i.e. the population is squeezed. The narrow trophic niche of Arctic charr compared to perch, roach and burbot, revealed by stable isostope analysis, supports this conclusion.

  8. Long-term rearing of Arctic charr Salvelinus alpinus under different salinity regimes at constant temperature.

    Science.gov (United States)

    Arnason, T; Gunnarsson, S; Imsland, A K; Thorarensen, H; Smáradóttir, H; Steinarsson, A; Gústavsson, A; Johansson, M; Björnsson, B Th

    2014-10-01

    Arctic charr Salvelinus alpinus of the Hólar strain (mean ± s.e. body mass = 152·1 ± 3·1 g) were reared at four different salinity regimes at a constant temperature of 7·4° C. Two groups were given a three-month acclimation in salinity 18 before the salinity was increased to either 25 or 29 (groups called A25 and A29), and two groups were reared in salinities 25 or 29 over the full experimental period of 409 days (groups called F25 and F29). In the first 3 months, the A25 and A29 groups had the highest growth rates. By October 2011, there were no significant differences (two-way nested ANOVA, P > 0·05) in the mean body masses among A25, F25 and F29 (c. 1450 g), whereas A29 had a lower mean mass (1282 g). The growth in the last period from October 2011 to January 2012 was reduced by sexual maturation in the highest salinity regimes (A29 and F29), whereas fish in groups A25 and F25 showed high growth throughout the study. Males in all salinity groups had higher growth rates than females for the most part of the study, but the divergence between the sexes was most pronounced in the highest salinity regimes. All salinity groups showed distinct changes in Na(+) , K(+) -ATPase activity, with high activity in spring and summer, and lower activity in the autumn. Plasma sodium (Na(+) ) levels were stable indicating that none of the experimental groups had problems in maintaining hydromineral balance during the study. While plasma leptin levels were not affected by salinity regimes, it was noted that these levels were 13-30% higher in fish with empty guts compared with those having food in their gut at the time of sampling. This suggests a link between leptin levels and food intake, indicating that this hormone may play a role in food intake and energy allocation in fishes. PMID:25053158

  9. Optimal swimming speeds reflect preferred swimming speeds of brook charr (Salvelinus fontinalis Mitchill, 1874)

    OpenAIRE

    Tudorache, Christian; O’Keefe, Robyn A.; Benfey, Tillmann J.

    2011-01-01

    Several measures have been developed to quantify swimming performance to understand various aspects of ecology and behaviour, as well as to help design functional applications for fishways and aquaculture. One of those measures, the optimal swimming speed, is the speed at which the cost of transport (COT) is minimal, where COT is defined as the cost of moving unit mass over unit distance. The experimental protocol to determine the optimal swimming speed involves forced-swimming in a flume or ...

  10. Differences in organotin accumulation in relation to life history in the white-spotted charr Salvelinus leucomaenis

    International Nuclear Information System (INIS)

    Research highlights: → Otolith Sr:Ca ratios in sea-run type were higher than those in freshwater-residents. → TBT and TPT concentrations in sea-run type were higher than those in freshwater-residents. → Sea-run type have higher risk of TBT and TPT than freshwater-residents in white-spotted charr. - Abstract: To examine the accumulation pattern of organotins (OTs) in relation to the migration of diadromous fish, tributyltin (TBT) and triphenyltin (TPT) and their derivatives were determined in the muscle tissue of both sea-run (anadromous) and freshwater-resident (nonanadromous) types of the white-spotted charr Salvelinus leucomaenis. Ontogenic changes in otolith strontium (Sr) and calcium (Ca) concentrations were examined along life history transect to discriminate migration type. Mean Sr:Ca ratio from the core to the edge of the otolith in sea-run individuals was significantly higher than those in freshwater-resident one. There were no significant correlations in S. leucomaenis between OT accumulation and various biological characteristics. It is noteworthy that TBT and TPT concentrations in sea-run type were significantly higher than those in freshwater-resident individuals, although they are both of the same species. These results suggest that sea-run S. leucomaenis have a higher ecological risk of OT exposure than freshwater-residents during their life histories.

  11. In vitro effects of the extracellular protein of Renibacterium salmoninarum on phagocyte function in brook trout (Salvelinus fontinalis).

    Science.gov (United States)

    Densmore, C L; Smith, S A; Holladay, S D

    1998-04-30

    Renibacterium salmoninarum is a facultative intracellular pathogen often found in host phagocytes where it appears to successfully avoid the host fish's immunological defenses. The objective of this investigation was to determine if soluble extracellular protein (ECP) produced by R. salmoninarum may contribute to the immunomodulation in bacterial kidney disease (BKD) via inhibition of phagocyte respiratory burst and/or phagocytosis mechanisms. Splenic cells from adult brook trout (Salvelinus fontinalis) were incubated with two different concentrations of ECP (0.1 mg/ml and 1.0 mg/ml) and viable R. salmoninarum. Splenic cell cultures were evaluated for respiratory burst activity via flow cytometry with the dichlorofluorescin diacetate (DCF-DA) assay and for phagocytosis via light microscopic assessment of microsphere engulfment. Respiratory burst activity was significantly inhibited in all treatment groups as compared to untreated fish, while no differences were noted in phagocytic activity. PMID:9646439

  12. Preference and avoidance pH of brook trout Salvelinus fontinalis and brown trout Salmo trutta exposed to different holding pH.

    Science.gov (United States)

    Fost, B A; Ferreri, C P

    2015-08-01

    The goal of this study was to determine if short-term exposure of brook trout Salvelinus fontinalis and brown trout Salmo trutta to a lower pH than found in their source stream results in a shift in preference or avoidance pH. The lack of a shift in preference or avoidance pH of adult S. fontinalis and S. trutta suggests that these species can be held at a pH different from the source waterbody for a short period of time without altering preference or avoidance pH behaviour. PMID:26147766

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

    Science.gov (United States)

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

    2013-01-01

    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.

  14. Genetic and morphological divergence in three strains of brook trout Salvelinus fontinalis commonly stocked in Lake Superior.

    Directory of Open Access Journals (Sweden)

    Garrett J McKinney

    Full Text Available Fitness related traits often show spatial variation across populations of widely distributed species. Comparisons of genetic variation among populations in putatively neutral DNA markers and in phenotypic traits susceptible to selection (QST FST analysis can be used to determine to what degree differentiation among populations can be attributed to selection or genetic drift. Traditionally, QST FST analyses require a large number of populations to achieve sufficient statistical power; however, new methods have been developed that allow QST FST comparisons to be conducted on as few as two populations if their pedigrees are informative. This study compared genetic and morphological divergence in three strains of brook trout Salvelinus fontinalis that were historically or currently used for stocking in the Lake Superior Basin. Herein we examined if morphological divergence among populations showed temporal variation, and if divergence could be attributed to selection or was indistinguishable from genetic drift. Multivariate QST FST analysis showed evidence for divergent selection between populations. Univariate analyses suggests that the pattern observed in the multivariate analyses was largely driven by divergent selection for length and weight, and moreover by divergence between the Assinica strain and each of the Iron River and Siskiwit strains rather than divergent selection between each population pair. While it could not be determined if divergence was due to natural selection or inadvertent artificial selection in hatcheries, selected differences were consistent with patterns of domestication commonly found in salmonids.

  15. Growth Performance, Food Intake and Feed Converison Ratios in Rainbow (Onchorynchus mykiss) and Brook Trout (Salvelinus fontinalis) Reared as a Single and Mixed Species

    OpenAIRE

    Okumuş, İbrahim; ÇELİKKALE, M. Salih; KURTOĞLU, İ. Zeki; BAŞÇINAR, Nadir

    1998-01-01

    Growth performances, daily food consumption and feed conversion ratios of rainbow (Onchorynchus mykiss) and brook trout (Salvelinus fontinalis) reared as single and mixed species were compared. During the experimental period, which lasted for about a growing season (December - June, 217 days), mean % weight increment of single species brook trout group were maximum (from 18.2 to 165.6 g), followed by mixed rainbow (26.8 to 241.6 g) and brook trout (17.0 to 151.8 g), and single species rainb...

  16. Effective number of breeders, effective population size and their relationship with census size in an iteroparous species, Salvelinus fontinalis.

    Science.gov (United States)

    Ruzzante, Daniel E; McCracken, Gregory R; Parmelee, Samantha; Hill, Kristen; Corrigan, Amelia; MacMillan, John; Walde, Sandra J

    2016-01-27

    The relationship between the effective number of breeders (Nb) and the generational effective size (Ne) has rarely been examined empirically in species with overlapping generations and iteroparity. Based on a suite of 11 microsatellite markers, we examine the relationship between Nb, Ne and census population size (Nc) in 14 brook trout (Salvelinus fontinalis) populations inhabiting 12 small streams in Nova Scotia and sampled at least twice between 2009 and 2015. Unbiased estimates of Nb obtained with individuals of a single cohort, adjusted on the basis of age at first maturation (α) and adult lifespan (AL), were from 1.66 to 0.24 times the average estimates of Ne obtained with random samples of individuals of mixed ages (i.e. [Formula: see text]). In turn, these differences led to adjusted Ne estimates that were from nearly five to 0.7 times the estimates derived from mixed-aged individuals. These differences translate into the same range of variation in the ratio of effective to census population size [Formula: see text] within populations. Adopting [Formula: see text] as the more precise and unbiased estimates, we found that these brook trout populations differ markedly in their effective to census population sizes (range approx. 0.3 to approx. 0.01). Using AgeNe, we then showed that the variance in reproductive success or reproductive skew varied among populations by a factor of 40, from Vk/k ≈ 5 to 200. These results suggest wide differences in population dynamics, probably resulting from differences in productivity affecting the intensity of competition for access to mates or redds, and thus reproductive skew. Understanding the relationship between Ne, Nb and Nc, and how these relate to population dynamics and fluctuations in population size, are important for the design of robust conservation strategies in small populations with overlapping generations and iteroparity. PMID:26817773

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

    Science.gov (United States)

    Kanno, Y.; Vokoun, J.C.; Letcher, B.H.

    2011-01-01

    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. ?? 2011 Blackwell Publishing Ltd.

  18. Quarantine of Aeromonas salmonicida-harboring ebonyshell mussels (Fusconaia ebena) prevents transmission of the pathogen to brook trout (Salvelinus fontinalis)

    Science.gov (United States)

    Starliper, C.E.

    2005-01-01

    Furunculosis, caused by the bacterium Aeromonas salmonicida, was artificially induced in brook trout (Salvelinus fontinalis) in an experimental tank. Ebonyshells (Fusconaia ebena) were placed to cohabit with these fish to acquire the pathogen through siphoning. After 2 wk of cohabitation, 10 of the mussels were assayed by bacterial culture and all were found to harbor A. salmonicida. The mean cell count from soft tissue homogenates was 1.84 ?? 105 cfu/g, which comprised an average 14.41% of the total bacteria isolated from tissues. From the fluids, a mean of 2.84 ?? 105 A. salmonicida cfu/mL was isolated, which comprised an average of 17.29% of the total bacterial flora. The mussels were removed from the cohabitation tank and distributed equally among five previously disinfected tanks, 35 per tank. The F. ebena in each tank were allowed to depurate A. salmonicida for various durations: 1, 5, 10, 15 or 30 days. After each group had depurated for their assigned time, 10 were assayed for bacteria, tank water was tested, and 20 pathogen-free bioindicator brook trout were added to cohabit with the remaining mussels. Depuration was considered successful if A. salmonicida was not isolated from tank water or the mussels, and there was no infection or mortality to bioindicator fish. After 1 day of depuration, A. salmonicida was not isolated from the soft tissues; however, it was isolated from one of the paired fluids (10% prevalence). The tank water tested positive, and the bioindicator fish became infected and died. From the 5-day depuration group, A. salmonicida was not isolated from soft tissues, but was isolated from three fluids (30%; mean = 1.56 ?? 102 cfu/mL). Tank water from the 5-day group was negative, and there was no mortality among the bioindicator fish. However, A. salmonicida was isolated from 2 of 20 fish at the end of the 14-day observation period. One F. ebena fluid sample was positive for A. salmonicida from the 10-day depuration group, but none of the

  19. Morphological, ecological and behavioural differentiation of sympatric profundal and pelagic Arctic charr (Salvelinus alpinus) in Loch Dughaill Scotland

    OpenAIRE

    Hooker, O.E.; Barry, J; Van Leeuwen, T. E.; Lyle, A.; Newton, Jason; Cunningham, P.; Adams, C.E.

    2016-01-01

    Phenotypic variation in populations of fishes that inhabit postglacial lakes is often associated with trophic specialisations. A common sympatric foraging divergence seen in Arctic charr is into either plankton or littoral-zoobenthos feeding specialisms. In this study, we report a sympatric polymorphic Arctic charr population which is not centred on this divergence but instead manifests as a plankton (pelagic)—profundal zoobenthos foraging specialisms. The head shape of profundal fish was rou...

  20. From autochthonous to allochthonous resources: seasonal shifts in food use by stream-dwelling YOY Arctic charr Salvelinus alpinus through the ice-free season.

    Science.gov (United States)

    Sánchez-Hernández, J; Gabler, H-M; Amundsen, P-A

    2016-02-01

    Substantial seasonal changes in resource use associated with enhanced water-column use were revealed in stream-living YOY Arctic charr Salvelinus alpinus during the ice-free season. In July, YOY individuals showed a diet dominated by aquatic invertebrates (mainly Chironomidae larvae), but despite the small size of the fish, the abundance of terrestrial insects in their diet increased markedly from July to September (from 1·9 to 62·8%). Similarly, the frequency of surface drifting foragers, i.e. individuals feeding on allochthonous resources, increased from July to September (from 20·6 to 80%); allochthonous resources thus constituting an important energy subsidy for YOY S. alpinus during the late sub-Arctic summer. PMID:26577804

  1. Satiation meal and the effects of meal and body sizes on gastric evacuation rate in brook trout Salvelinus fontinalis fed commercial pellets.

    Science.gov (United States)

    Khan, U; Seyhan, K; Başçinar, N; Başçinar, N S

    2016-08-01

    Gastric evacuation (GE) experiments were performed on brook trout Salvelinus fontinalis fed commercial food pellets. The experiments included small fish (36 g; 15 cm total length, LT ) fed meals of 0·2, 0·4 and 0·8 g and large fish (152 g; 23 cm) fed meals of 0·8, 2·0 and 4·0 g at temperatures ranging from 15·1 to 18·2° C. The stomach contents were thereafter sampled and weighed at 3 h intervals until the first empty stomach was observed. The course of GE was examined by use of a general power function of the data that revealed that the square-root function described the GE rate (GER) by the current stomach content mass independently of original meal size. Using the square-root function, the relationship between GER and fish size was described by a power function of fish length, whereas the effect of temperature was described by a simple exponential function. GER of the commercial pellets fed to S. fontinalis could thus be described by dStdt=-0·000464L1·31e0·052TSt (g h(-1) ), where St is stomach mass (g) at time t (h), L is total fish length (cm) and T is temperature (° C). The result of this study should provide a useful tool for planning of feeding regimes in production of S. fontinalis by optimizing growth and minimizing food waste. PMID:27282124

  2. Phenotypic and genetic variation in two North American arctic charr (Salvelinus alpinus) stocks cultured in recirculating aquaculture systems

    Science.gov (United States)

    Arctic charr were obtained as eggs from two North American sources, an eastern (Fraser River, Canada) and a western (Bristol Bay, Alaska) stock. Fish from each family (n=38) were pit tagged at approximately 12 months post-hatch (eastern mean+SE=247+/-13g, western mean+SE=220+/-g) and stocked commun...

  3. Arctic charr farming

    OpenAIRE

    Brännäs, Eva; Larsson, Stefan; Saether, Björn Steinar; Siikavuopio, Sten Ivar; Thorarensen, Helgi; Sigurgeirsson, Ólafur; Jeuthe, Henrik

    2011-01-01

    The Arctic charr (Salvelinus alpinus L.) is a holarctic salmonid fish species with both landlocked and anadromous populations. In Scandinavia it is mainly found in the mountain area, but it also appears in deep and large lake further south, i.e. in the Alps. It is the northernmost freshwater fish and A. charr is generally regarded as the most cold-adapted freshwater fish. A. charr has been commercially farmed since the early 90ths and today, the total production is 3000, 2300 and 700 tonnes/y...

  4. Comparative analysis of total mercury concentrations in anadromous and non-anadromous Arctic charr (Salvelinus alpinus) from eastern Canada

    International Nuclear Information System (INIS)

    Previous research has documented that total mercury concentrations ([THg]) are lower in anadromous Arctic charr than in non-anadromous conspecifics, but the two life-history forms have rarely been studied together. Here, data from nine pairs of closely-located anadromous and non-anadromous Arctic charr populations were used to explore the impact of biological and life-history factors on individual [THg] across a range of latitudes (49–81° N) in eastern Canada. Unadjusted mean [THg] ranged from 20 to 114 ng/g wet weight (ww) in anadromous populations, and was significantly higher in non-anadromous populations, ranging from 111 to 227 ng/g ww. Within-population variations in [THg] were best explained by fish age, and were often positively related to fork-length and δ15N-inferred trophic level. Differences in [THg] were not related to differences in length-at-age (i.e., average somatic growth rate) among populations of either life-history type. Mercury concentrations were not related to site latitude in either the anadromous or non-anadromous fish. We conclude that the difference in Arctic charr [THg] with life-history type could not be explained by differences in fish age, fork-length, trophic position, or length-at-age, and discuss possible factors contributing to low mercury concentrations in anadromous, relative to freshwater, fish. - Highlights: ► Total mercury concentrations ([THg]) were measured in 9 co-located anadromous and non-anadromous Arctic charr populations. ► Mean [THg] in non-anadromous populations exceeded mean [THg] in spatially paired anadromous populations. ► Among-individual variation in [THg] was best explained by fish age. ► The lower [THg] in anadromous fish could not be explained by differences in age, fork-length, trophic level, or growth rate. ► Variations in Arctic charr [THg] were independent of latitude (49–81° N) in eastern Canada

  5. Analysis of trade-offs between threats of invasion by nonnative brook trout (Salvelinus fontinalis) and intentional isolation for native westslope cutthroat trout (Oncorhynchus clarkii lewisi)

    Science.gov (United States)

    Peterson, D.P.; Rieman, B.E.; Dunham, J.B.; Fausch, K.D.; Young, M.K.

    2008-01-01

    Native salmonid fishes often face simultaneous threats from habitat fragmentation and invasion by nonnative trout species. Unfortunately, management actions to address one may create or exacerbate the other. A consistent decision process would include a systematic analysis of when and where intentional use or removal of barriers is the most appropriate action. We developed a Bayesian belief network as a tool for such analyses. We focused on native westslope cutthroat trout (Oncorhynchus clarkii lewisi) and nonnative brook trout (Salvelinus fontinalis) and considered the environmental factors influencing both species, their potential interactions, and the effects of isolation on the persistence of local cutthroat trout populations. The trade-offs between isolation and invasion were strongly influenced by size and habitat quality of the stream network to be isolated and existing demographic linkages within and among populations. An application of the model in several sites in western Montana (USA) showed the process could help clarify management objectives and options and prioritize conservation actions among streams. The approach can also facilitate communication among parties concerned with native salmonids, nonnative fish invasions, barriers and intentional isolation, and management of the associated habitats and populations. ?? 2008 NRC.

  6. Ontogenetic dynamics of infection with Diphyllobothrium spp. cestodes in sympatric Arctic charr Salvelinus alpinus (L.) and brown trout Salmo trutta L.

    Science.gov (United States)

    Henrickson, Eirik H.; Knudsen, Rune; Kristoffersen, Roar; Kuris, Armand M.; Lafferty, Kevin D.; Siwertsson, Anna; Amundsen, Per-Arne

    2015-01-01

    The trophic niches of Arctic charr and brown trout differ when the species occur in sympatry. Their trophically transmitted parasites are expected to reflect these differences. Here, we investigate how the infections of Diphyllobothrium dendriticum and D. ditremum differ between charr and trout. These tapeworms use copepods as their first intermediate hosts and fish can become infected as second intermediate hosts by consuming either infected copepods or infected fish. We examined 767 charr and 368 trout for Diphyllobothrium plerocercoids in a subarctic lake. The prevalence of D. ditremum was higher in charr (61.5%) than in trout, (39.5%), but the prevalence of D. dendriticum was higher in trout (31.2%) than in charr (19.3%). Diphyllobothrium spp. intensities were elevated in trout compared to charr, particularly for D. dendriticum. Large fish with massive parasite burdens were responsible for the high Diphyllobothrium spp. loads in trout. We hypothesize that fish prey may be the most important source for the Diphyllobothrium spp. infections in trout, whereas charr predominantly acquire Diphyllobothrium spp. by feeding on copepods. Our findings support previous suggestions that the ability to establish in a second piscine host is greater for D. dendriticum than for D. ditremum.

  7. Bioavailability of metals in stream food webs and hazards to brook trout (Salvelinus fontinalis) in the upper Animas River watershed, Colorado

    Science.gov (United States)

    Besser, J.M.; Brumbaugh, W.G.; May, T.W.; Church, S.E.; Kimball, B.A.

    2001-01-01

    The water quality, habitats, and biota of streams in the upper Animas River watershed of Colorado, USA, are affected by metal contamination associated with acid drainage. We determined metal concentrations in components of the food web of the Animas River and its tributaries - periphyton (aufwuchs), benthic invertebrates, and livers of brook trout (Salvelinus fontinalis) - and evaluated pathways of metal exposure and hazards of metal toxicity to stream biota. Concentrations of the toxic metals cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in periphyton, benthic invertebrates, and trout livers from one or more sites in the upper Animas River were significantly greater than those from reference sites. Periphyton from sites downstream from mixing zones of acid and neutral waters had elevated concentrations of aluminum (Al) and iron (Fe) reflecting deposition of colloidal Fe and Al oxides, and reduced algal biomass. Metal concentrations in benthic invertebrates reflected differences in feeding habits and body size among taxa, with greatest concentrations of Zn, Cu, and Cd in the small mayfly Rhithrogena, which feeds on periphyton, and greatest concentrations of Pb in the small stonefly Zapada, a detritivore. Concentrations of Zn and Pb decreased across each trophic linkage, whereas concentrations of Cu and Cd were similar across several trophic levels, suggesting that Cu and Cd were more efficiently transferred via dietary exposure. Concentrations of Cu in invertebrates and trout livers were more closely associated with impacts on trout populations and invertebrate communities than were concentrations of Zn, Cd, or Pb. Copper concentrations in livers of brook trout from the upper Animas River were substantially greater than background concentrations and approached levels associated with reduced brook trout populations in field studies and with toxic effects on other salmonids in laboratory studies. These results indicate that bioaccumulation and transfer of

  8. Genomic arrangement of salinity tolerance QTLs in salmonids: A comparative analysis of Atlantic salmon (Salmo salar with Arctic charr (Salvelinus alpinus and rainbow trout (Oncorhynchus mykiss

    Directory of Open Access Journals (Sweden)

    Norman Joseph D

    2012-08-01

    Full Text Available Abstract Background Quantitative trait locus (QTL studies show that variation in salinity tolerance in Arctic charr and rainbow trout has a genetic basis, even though both these species have low to moderate salinity tolerance capacities. QTL were observed to localize to homologous linkage group segments within putative chromosomal regions possessing multiple candidate genes. We compared salinity tolerance QTL in rainbow trout and Arctic charr to those detected in a higher salinity tolerant species, Atlantic salmon. The highly derived karyotype of Atlantic salmon allows for the assessment of whether disparity in salinity tolerance in salmonids is associated with differences in genetic architecture. To facilitate these comparisons, we examined the genomic synteny patterns of key candidate genes in the other model teleost fishes that have experienced three whole-genome duplication (3R events which preceded a fourth (4R whole genome duplication event common to all salmonid species. Results Nine linkage groups contained chromosome-wide significant QTL (AS-2, -4p, -4q, -5, -9, -12p, -12q, -14q -17q, -22, and −23, while a single genome-wide significant QTL was located on AS-4q. Salmonid genomes shared the greatest marker homology with the genome of three-spined stickleback. All linkage group arms in Atlantic salmon were syntenic with at least one stickleback chromosome, while 18 arms had multiple affinities. Arm fusions in Atlantic salmon were often between multiple regions bearing salinity tolerance QTL. Nine linkage groups in Arctic charr and six linkage group arms in rainbow trout currently have no synteny alignments with stickleback chromosomes, while eight rainbow trout linkage group arms were syntenic with multiple stickleback chromosomes. Rearrangements in the stickleback lineage involving fusions of ancestral arm segments could account for the 21 chromosome pairs observed in the stickleback karyotype. Conclusions Salinity tolerance in

  9. Basal mercury concentrations and biomagnification rates in freshwater and marine food webs: Effects on Arctic charr (Salvelinus alpinus) from eastern Canada

    International Nuclear Information System (INIS)

    Patterns of total Hg (THg) and methyl Hg (MeHg) biomagnification were investigated in six pairs of co-located lacustrine and marine food webs supporting a common predator, Arctic charr. Mercury biomagnification rates (the slope of log Hg concentration versus δ15N-inferred trophic level) did not differ significantly between the two feeding habitats for either THg or MeHg, but THg and MeHg concentrations at the base of the food web were higher in the lacustrine environment than in the marine environment. The proportion of THg as MeHg was related to trophic level, and the relationship was statistically similar in the lacustrine and marine habitats. The biomagnification rate of MeHg exceeded that of THg in both habitats. We conclude that the known difference in Hg concentration between anadromous and non-anadromous Arctic charr is driven by differential Hg concentrations at the base of the lacustrine and marine foodwebs, and not by differential biomagnification rates. - Highlights: ► Concentrations of total mercury ([THg]) and methylmercury ([MeHg]) were measured in 6 paired lacustrine and marine food webs. ► Biomagnification rates (slopes of [THg] or [MeHg] versus δ15N-inferred trophic level) were similar in the two habitat types. ► Mercury concentrations at the base of the food web were higher in lacustrine than in marine food webs. ► The percentage of methylated mercury increased with trophic level similarly in the two habitat types. The biomagnification rate of MeHg exceeded that of THg in both habitats

  10. Basal mercury concentrations and biomagnification rates in freshwater and marine food webs: Effects on Arctic charr (Salvelinus alpinus) from eastern Canada

    Energy Technology Data Exchange (ETDEWEB)

    Velden, S. van der, E-mail: sdorn@uwaterloo.ca [Department of Biology, University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1 (Canada); Dempson, J.B. [Fisheries and Oceans Canada, St. John' s, Newfoundland and Labrador, Canada, A1C 5X1 (Canada); Evans, M.S. [Environment Canada, Saskatoon, Saskatchewan, Canada, S7N 3H5 (Canada); Muir, D.C.G. [Environment Canada, Burlington, Ontario, Canada, L7R 4A6 (Canada); Power, M., E-mail: m3power@uwaterloo.ca [Department of Biology, University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1 (Canada)

    2013-02-01

    Patterns of total Hg (THg) and methyl Hg (MeHg) biomagnification were investigated in six pairs of co-located lacustrine and marine food webs supporting a common predator, Arctic charr. Mercury biomagnification rates (the slope of log Hg concentration versus δ{sup 15}N-inferred trophic level) did not differ significantly between the two feeding habitats for either THg or MeHg, but THg and MeHg concentrations at the base of the food web were higher in the lacustrine environment than in the marine environment. The proportion of THg as MeHg was related to trophic level, and the relationship was statistically similar in the lacustrine and marine habitats. The biomagnification rate of MeHg exceeded that of THg in both habitats. We conclude that the known difference in Hg concentration between anadromous and non-anadromous Arctic charr is driven by differential Hg concentrations at the base of the lacustrine and marine foodwebs, and not by differential biomagnification rates. - Highlights: ► Concentrations of total mercury ([THg]) and methylmercury ([MeHg]) were measured in 6 paired lacustrine and marine food webs. ► Biomagnification rates (slopes of [THg] or [MeHg] versus δ{sup 15}N-inferred trophic level) were similar in the two habitat types. ► Mercury concentrations at the base of the food web were higher in lacustrine than in marine food webs. ► The percentage of methylated mercury increased with trophic level similarly in the two habitat types. ► The biomagnification rate of MeHg exceeded that of THg in both habitats.

  11. Incipient speciation through niche expansion: an example from the Arctic charr in a subarctic lake

    OpenAIRE

    Knudsen, Rune; Klemetsen, Anders; Amundsen, Per-Arne; Hermansen, Bjørn

    2006-01-01

    Two reproductive isolated morphs of Arctic charr (Salvelinus alpinus), termed profundal and littoral charr according to their different spawning habitats, co-occur in the postglacial lake Fjellfrøsvatn in North Norway. All profundal charr live in deep water their entire life and have a maximum size of 14 cm, while the littoral charr grow to 40 cm. Some small and young littoral charr move to the profundal zone in an ontogenetic habitat shift in the ice-free season and the rest of the populatio...

  12. Genome evolution in the fish family salmonidae: generation of a brook charr genetic map and comparisons among charrs (Arctic charr and brook charr with rainbow trout

    Directory of Open Access Journals (Sweden)

    Moghadam Hooman K

    2011-07-01

    species of charr (genus Salvelinus and a trout (genus Oncorhynchus have identified that linkage group arm arrangements are largely retained among these species. Previous studies have revealed that up to 7 regions of high duplicate marker retention occur between Salmo species (i.e., Atlantic salmon and brown trout and rainbow trout, with 5 of these regions exhibiting higher levels of pseudolinkage. Pseudolinkage was detected in the charr species (i.e., BC-1/21, AC-12/27, AC-6/23, = RT-2p/29q, RT-12p/16p, and RT-27p/31p, respectively consistent with three of the five 'salmonid-specific' pseudolinkage regions. Chromosome arms with the highest number of duplicated markers in rainbow trout are the linkage group arms with the highest retention of duplicated markers in both charr species.

  13. Development of spinal deformities in Atlantic salmon and Arctic charr fed diets supplemented with oxytetracycline

    International Nuclear Information System (INIS)

    Some individuals within populations of Atlantic salmon Salmo salar and Arctic charr Salvelinus alpinus fed diets supplemented with oxytetracycline (OTC) developed spinal deformations. Possible differences in feed intake and growth of spinally deformed fish relative to fish without any deformities were investigated. Amongst Atlantic salmon, 17% of the fish fed OTC-supplemented feed developed spinal fractures, whereas none of the fish receiving the basic feed did so. Despite deformation of the spinal column, the injured fish continued to feed and grow, but at lower rates than unaffected individuals. In contrast to Atlantic salmon, Arctic charr showed no signs of spinal fractures at any time during the 65-day experiment

  14. Aroclor 1254 exposure reduces disease resistance and innate immune responses in fasted arctic charr

    Science.gov (United States)

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

    2005-01-01

    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.

  15. PCB disruption of the hypothalamus-pituitary-interrenal axis involves brain glucocorticoid receptor downregulation in anadromous Arctic charr

    Science.gov (United States)

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

    2004-01-01

    We examined whether brain glucocorticoid receptor (GR) modulation by polychlorinated biphenyls (PCBs) was involved in the abnormal cortisol response to stress seen in anadromous Arctic charr (Salvelinus alpinus). Fish treated with Aroclor 1254 (0, 1, 10, and 100 mg/kg body mass) were maintained for 5 mo without feeding in the winter to mimic their seasonal fasting cycle, whereas a fed group with 0 and 100 mg/kg Aroclor was maintained for comparison. Fasting elevated plasma cortisol levels and brain GR content but depressed heat shock protein 90 (hsp90) and interrenal cortisol production capacity. Exposure of fasted fish to Aroclor 1254 resulted in a dose-dependent increase in brain total PCB content. This accumulation in fish with high PCB dose was threefold higher in fasted fish compared with fed fish. PCBs depressed plasma cortisol levels but did not affect in vitro interrenal cortisol production capacity in fasted charr. At high PCB dose, the brain GR content was significantly lower in the fasted fish and this corresponded with a lower brain hsp70 and hsp90 content. The elevation of plasma cortisol levels and upregulation of brain GR content may be an important adaptation to extended fasting in anadromous Arctic charr, and this response was disrupted by PCBs. Taken together, the hypothalamus-pituitary- interrenal axis is a target for PCB impact during winter emaciation in anadromous Arctic charr.

  16. Quantification of 15 bile acids in lake charr feces by ultra-high performance liquid chromatography–tandem mass spectrometry

    Science.gov (United States)

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

    2015-01-01

    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.

  17. Biological and life-history factors affecting total mercury concentrations in Arctic charr from Heintzelman Lake, Ellesmere Island, Nunavut

    Energy Technology Data Exchange (ETDEWEB)

    Velden, Shannon van der, E-mail: sdorn@sciborg.uwaterloo.ca [Department of Biology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1 (Canada); Reist, James D.; Babaluk, John A. [Freshwater Institute, Fisheries and Oceans Canada, Winnipeg, Manitoba, Canada R3T 2N6 (Canada); Power, Michael, E-mail: m3power@sciborg.uwaterloo.ca [Department of Biology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1 (Canada)

    2012-09-01

    A snapshot sample of Arctic charr (Salvelinus alpinus) from Heintzelman Lake (81 Degree-Sign 42 Prime N, 66 Degree-Sign 56 Prime W), Ellesmere Island, Canada was used to elucidate the biological and life-history factors potentially influencing individual total mercury (THg) concentrations. Migratory history was significant, with anadromous fish having a lower mean THg concentration (64 {mu}g/kg ww) than the non-anadromous Arctic charr (117 {mu}g/kg ww). The increase in individual THg concentration with age was shown to be independent of length-at-age when large and small individuals within the same age groups were compared. Similarly, the diets of individual Arctic charr were comparable regardless of size, and there was no apparent ontogenetic shift in diet that could explain differences in length-at-age or THg concentration among fast- and slow-growing groups of fish (i.e., fish of the same age but differing sizes). Maturity state was also not related to THg concentration, but appears to be related to differences in length-at-age, with slow-growing fish allocating more energy to reproduction than fast-growing conspecifics. The differences in THg concentration among individual Arctic charr were best explained by fish age. We suggest that the increase in mercury concentration with age can be altered by a shift in diet (e.g., to piscivory) or habitat (e.g., anadromy), but is otherwise unaffected by changes in size or length-at-age. -- Highlights: Black-Right-Pointing-Pointer Total mercury concentrations ([THg]) were measured in Arctic charr from a single lake in the Canadian high Arctic. Black-Right-Pointing-Pointer Anadromous Arctic charr had a significantly lower mean [THg] (64 {mu}g/kg ww) than the non-anadromous fish (117 {mu}g/kg ww). Black-Right-Pointing-Pointer Length-at-age (i.e., average somatic growth rate) was not related to mean [THg] when same-age groups were compared. Black-Right-Pointing-Pointer Prey resource use, determined by {delta}{sup 13}C and

  18. Biological and life-history factors affecting total mercury concentrations in Arctic charr from Heintzelman Lake, Ellesmere Island, Nunavut

    International Nuclear Information System (INIS)

    A snapshot sample of Arctic charr (Salvelinus alpinus) from Heintzelman Lake (81°42′N, 66°56′W), Ellesmere Island, Canada was used to elucidate the biological and life-history factors potentially influencing individual total mercury (THg) concentrations. Migratory history was significant, with anadromous fish having a lower mean THg concentration (64 μg/kg ww) than the non-anadromous Arctic charr (117 μg/kg ww). The increase in individual THg concentration with age was shown to be independent of length-at-age when large and small individuals within the same age groups were compared. Similarly, the diets of individual Arctic charr were comparable regardless of size, and there was no apparent ontogenetic shift in diet that could explain differences in length-at-age or THg concentration among fast- and slow-growing groups of fish (i.e., fish of the same age but differing sizes). Maturity state was also not related to THg concentration, but appears to be related to differences in length-at-age, with slow-growing fish allocating more energy to reproduction than fast-growing conspecifics. The differences in THg concentration among individual Arctic charr were best explained by fish age. We suggest that the increase in mercury concentration with age can be altered by a shift in diet (e.g., to piscivory) or habitat (e.g., anadromy), but is otherwise unaffected by changes in size or length-at-age. -- Highlights: ► Total mercury concentrations ([THg]) were measured in Arctic charr from a single lake in the Canadian high Arctic. ► Anadromous Arctic charr had a significantly lower mean [THg] (64 μg/kg ww) than the non-anadromous fish (117 μg/kg ww). ► Length-at-age (i.e., average somatic growth rate) was not related to mean [THg] when same-age groups were compared. ► Prey resource use, determined by δ13C and δ15N isotopes and gut contents, was similar among fast- and slow-growing fish. ► Maturity state was not related to [THg], but the slow-growing group

  19. Effect of acidic lake water on survival of aurora trout (Salvelinus fontinalis) embryos and alevins

    Energy Technology Data Exchange (ETDEWEB)

    Snucins, E.J.; Liimatainen, V.A.; Gale, P.A.

    1988-01-01

    During the 1960s the aurora trout, a rare color variant of the brook trout, disappeared from its native waters in northeastern Ontario. Its disappearance was attributed to acidification of the waters by atmospheric deposition of industrial emissions from metal smelters at Sudbury, Ontario. Recently, water quality in the Sudbury area has improved due to emission reductions. These experiments were designed to assess the toxicity of current water quality in the native lakes of aurora trout. During May 1984, hatchery-reared aurora trout alevins were held for 4 days in 3 of their native lakes (Whiligig, Whitepine and Wilderness with pH 4.5-4.8) and a control lake, Regan Lake (pH 6.5), and survival rates were assessed. In a second bioassay, embryos and alevins were buried in the substrate at 3 groundwater upwelling sites, and survival rates were assessed. The final test involved a 14-day exposure of groundwater-reared fish to ambient conditions.

  20. Hydrodynamic function of dorsal and anal fins in brook trout (Salvelinus fontinalis).

    Science.gov (United States)

    Standen, E M; Lauder, G V

    2007-01-01

    Recent kinematic and hydrodynamic studies on fish median fins have shown that dorsal fins actively produce jets with large lateral forces. Because of the location of dorsal fins above the fish's rolling axis, these lateral forces, if unchecked, would cause fish to roll. In this paper we examine the hydrodynamics of trout anal fin function and hypothesize that anal fins, located below the fish's rolling axis, produce similar jets to the dorsal fin and help balance rolling torques during swimming. We simultaneously quantify the wake generated by dorsal and anal fins in brook trout by swimming fish in two horizontal light sheets filmed by two synchronized high speed cameras during steady swimming and manoeuvring. Six major conclusions emerge from these experiments. First, anal fins produce lateral jets to the same side as dorsal fins, confirming the hypothesis that anal fins produce fluid jets that balance those produced by dorsal fins. Second, in contrast to previous work on sunfish, neither dorsal nor anal fins produce significant thrust during steady swimming; flow leaves the dorsal and anal fins in the form of a shear layer that rolls up into vortices similar to those seen in steady swimming of eels. Third, dorsal and anal fin lateral jets are more coincident in time than would be predicted from simple kinematic expectations; shape, heave and pitch differences between fins, and incident flow conditions may account for the differences in timing of jet shedding. Fourth, relative force and torque magnitudes of the anal fin are larger than those of the dorsal fin; force differences may be due primarily to a larger span and a more squarely shaped trailing edge of the anal fin compared to the dorsal fin; torque differences are also strongly influenced by the location of each fin relative to the fish's centre of mass. Fifth, flow is actively modified by dorsal and anal fins resulting in complex flow patterns surrounding the caudal fin. The caudal fin does not encounter free-stream flow, but rather moves through incident flow greatly altered by the action of dorsal and anal fins. Sixth, trout anal fin function differs from dorsal fin function; although dorsal and anal fins appear to cooperate functionally, there are complex interactions between other fins and free stream perturbations that require independent dorsal and anal fin motion and torque production to maintain control of body position. PMID:17210968

  1. Does the introduced brook trout ( Salvelinus fontinalis) affect growth of the native brown trout ( Salmo trutta)?

    Science.gov (United States)

    Korsu, Kai; Huusko, Ari; Muotka, Timo

    2009-03-01

    Non-native brook trout have become widely established in North European streams. We combined evidence from an artificial-stream experiment and drainage-scale field surveys to examine whether brook trout suppressed the growth of the native brown trout (age 0 to age 2). Our experimental results demonstrated that brown trout were unaffected by the presence of brook trout but that brook trout showed reduced growth in the presence of brown trout. However, the growth reduction only appeared in the experimental setting, indicating that the reduced spatial constraint of the experimental system may have forced the fish to unnaturally intense interactions. Indeed, in the field, no effect of either species on the growth of the putative competitor was detected. These results caution against uncritical acceptance of findings from small-scale experiments because they rarely scale up to more complex field situations. This and earlier work suggest that the establishment of brook trout in North European streams has taken place mainly because of the availability of unoccupied (or underutilized) niche space, rather than as a result of species trait combinations or interspecific competition per se.

  2. DETECTION OF RENIBACTERIUM SALMONINARUM IN TISSUE OF BROOK TROUT (SALVELINUS FONTINALIS BY NESTED RT–PCR

    Directory of Open Access Journals (Sweden)

    Irena Vardić

    2007-01-01

    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

  3. Reproductive behaviour and sex trait allocations in an external fertilizer – the Charr (Salvelinus alpinus)

    OpenAIRE

    Figenschou, Lars

    2010-01-01

    This thesis illuminates several aspects of mate choice and sexual selection in a species with external fertilization and no parental care. At a general level we have contributed to the basic framework within evolutionary biology and ecology and at a more specific level, as the proximate mechanisms controlling the associations between immune response, parasite intensities and traits indicative of sperm quality are not straightforward, we examined the effect of increased immunological activity ...

  4. Water quality in recirculating aquaculture systems (ras) for arctic charr (salvelinus alpinus L.) culture.

    OpenAIRE

    Isla Molleda , M.

    2008-01-01

    Recirculating aquaculture systems (RAS) for fish culture have been used for more than three decades. The interest in RAS is due to their have advantages such as greatly reduced land and water requirements in places where the water resources are limited; but the RAS have also disadvantages like the deterioration of the water quality if the water treatment processes within the system are not controlled properly. The water quality problems in RAS were associated with low DO and high fish waste m...

  5. Ontogeny, variation, and homology in Salvelinus alpinus caudal skeleton (Teleostei: Salmonidae).

    Science.gov (United States)

    Grünbaum, Thomas; Cloutier, Richard

    2010-01-01

    The ontogeny of the caudal skeleton in the Arctic charr, Salvelinus alpinus was examined using an extensive series of cleared and stained specimens. We demonstrate the presence of skeletal components never reported previously within the Salmonidae. In contrast to the generalized condition for salmonids, seven hypurals (instead of six), and four uroneurals (instead of three) have been found in some specimens. Variation in the number and condition of epurals is documented. New hypotheses are proposed concerning (1) relationships among centra and their associated elements, (2) phylogenetic distribution of caudal characters within the Salmonidae, and (3) homology of caudal components. Using the published phylogenetic hypotheses, we provide evidence, that a seventh hypural and a fourth uroneural are taxic atavism in salmonids. The development of the salmonid homocercal fin is discussed in the light of a polyural scheme based on evidences of a one-to-one relationship among ural centra and their associated elements. PMID:19603412

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Morfologicko-fyziologické rozdíly sivena amerického Salvelinus fontinalis a jeho hybrida Salvelinus alpinus x Salvelinus fontinalis chovaných v recirkulačních systémech

    Czech Academy of Sciences Publication Activity Database

    Halačka, Karel; Vítek, T.; Mareš, J.

    Brno : Tribun EU, 2012 - (Soukalová, K.). s. 12 ISBN 978-80-263-0307-7. [Česká ichtyologická konference /13./. 24.10.2012-26.10.2012, Červená nad Vltavou] Institutional support: RVO:68081766 Keywords : Hybridization * Aquaculture Subject RIV: EH - Ecology, Behaviour

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

    International Nuclear Information System (INIS)

    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)

  9. Metallothionein in brook trout (Salvenlinus fontinalis) as a biological indicator of cadmium stress

    International Nuclear Information System (INIS)

    A cadmium-saturation technique for quantifying metallothionein in mammalian tissues was evaluated for use in fish tissue. Metallothionein characteristically binds 7 gram-atoms of a metal such as cadmium per mole of protein so saturating MT with respect to one metal and then quantifying that metal would thus result in the indirect quantification of MT. The authors administered 3 mg 109cadmium/kg body weight by intraperitoneal injection over a 5-day period to adult brook trout Salvelinus fontinalis to induce MT in liver and kidney tissues. Homogenates were centrifuged and the supernatant was used to quantitate cadmium in three fractions: 100,000 g supernatant, cadmium-saturated MT, and unsaturated MT. The cadmium-saturated MT method involved the following steps: saturation of MT in an aliquot of 100,000 g supernatant with excess cadmium; removal of excess cadmium by addition of 2% hemoglobin; denaturation of hemoglobin by heating at 1000C followed by rapid cooling on ice; centrifugation at 10,000 g; digestion of an aliquot of supernatant in concentrated nitric acid for 16 hours at 700C, and quantification of cadmium by atomic absorption and graphite furnace techniques or radiometric measurement with a scintillation counter. The cadmium saturation technique was modified in two ways so the amount of cadmium bound to unsaturated MT could be measured; first, the binding sites on MT were not saturated with excess cadmium, and second, the concentration of hemoglobin added to remove free cadmium and aid in coagulating low-molecular-weight proteins was 1% instead of 2%. The method gave precise measurements of MT concentrations when aliquots of liver homogenate which were analyzed separately were quantified by atomic absorption or radiometric measurements. Two to four times more cadmium and MT concentrated in the liver of treated fish than in the kidney

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

    Data.gov (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...

  11. Domestic feed sources to farmed Arctic charr (Salvelinus alpinus). An investigation of nutritional implications and impact on the ecological footprint

    OpenAIRE

    Muminović, Muhamed

    2010-01-01

    This study presents an overview of recapturing nutrients from Baltic Sea through mussel farming and producing mussel meal, detoxification of polluted fish into purified high quality fish meal and oil and introducing microorganisms as waste consumers as well as good protein sources for fish diets. Work on this study is focused on comparing growth performance of test diet, which has been made strictly of domestic (Baltic Sea) protein sources to commercial diet. Also, the study backs up the idea...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-01

    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. Genetic Diversity and Hybridisation between Native and Introduced Salmonidae Fishes in a Swedish Alpine Lake.

    Science.gov (United States)

    Faulks, Leanne; Östman, Örjan

    2016-01-01

    Understanding the processes underlying diversification can aid in formulating appropriate conservation management plans that help maintain the evolutionary potential of taxa, particularly under human-induced activities and climate change. Here we assessed the microsatellite genetic diversity and structure of three salmonid species, two native (Arctic charr, Salvelinus alpinus and brown trout, Salmo trutta) and one introduced (brook charr, Salvelinus fontinalis), from an alpine lake in sub-arctic Sweden, Lake Ånn. The genetic diversity of the three species was similar and sufficiently high from a conservation genetics perspective: corrected total heterozygosity, H'T = 0.54, 0.66, 0.60 and allelic richness, AR = 4.93, 5.53 and 5.26 for Arctic charr, brown trout and brook charr, respectively. There were indications of elevated inbreeding coefficients in brown trout (GIS = 0.144) and brook charr (GIS = 0.129) although sibling relationships were likely a confounding factor, as a high proportion of siblings were observed in all species within and among sampling locations. Overall genetic structure differed between species, Fst = 0.01, 0.02 and 0.04 in Arctic charr, brown trout and brook charr respectively, and there was differentiation at only a few specific locations. There was clear evidence of hybridisation between the native Arctic charr and the introduced brook charr, with 6% of individuals being hybrids, all of which were sampled in tributary streams. The ecological and evolutionary consequences of the observed hybridisation are priorities for further research and the conservation of the evolutionary potential of native salmonid species. PMID:27032100

  14. Genetic Diversity and Hybridisation between Native and Introduced Salmonidae Fishes in a Swedish Alpine Lake.

    Directory of Open Access Journals (Sweden)

    Leanne Faulks

    Full Text Available Understanding the processes underlying diversification can aid in formulating appropriate conservation management plans that help maintain the evolutionary potential of taxa, particularly under human-induced activities and climate change. Here we assessed the microsatellite genetic diversity and structure of three salmonid species, two native (Arctic charr, Salvelinus alpinus and brown trout, Salmo trutta and one introduced (brook charr, Salvelinus fontinalis, from an alpine lake in sub-arctic Sweden, Lake Ånn. The genetic diversity of the three species was similar and sufficiently high from a conservation genetics perspective: corrected total heterozygosity, H'T = 0.54, 0.66, 0.60 and allelic richness, AR = 4.93, 5.53 and 5.26 for Arctic charr, brown trout and brook charr, respectively. There were indications of elevated inbreeding coefficients in brown trout (GIS = 0.144 and brook charr (GIS = 0.129 although sibling relationships were likely a confounding factor, as a high proportion of siblings were observed in all species within and among sampling locations. Overall genetic structure differed between species, Fst = 0.01, 0.02 and 0.04 in Arctic charr, brown trout and brook charr respectively, and there was differentiation at only a few specific locations. There was clear evidence of hybridisation between the native Arctic charr and the introduced brook charr, with 6% of individuals being hybrids, all of which were sampled in tributary streams. The ecological and evolutionary consequences of the observed hybridisation are priorities for further research and the conservation of the evolutionary potential of native salmonid species.

  15. Genetic Diversity and Hybridisation between Native and Introduced Salmonidae Fishes in a Swedish Alpine Lake

    Science.gov (United States)

    Faulks, Leanne; Östman, Örjan

    2016-01-01

    Understanding the processes underlying diversification can aid in formulating appropriate conservation management plans that help maintain the evolutionary potential of taxa, particularly under human-induced activities and climate change. Here we assessed the microsatellite genetic diversity and structure of three salmonid species, two native (Arctic charr, Salvelinus alpinus and brown trout, Salmo trutta) and one introduced (brook charr, Salvelinus fontinalis), from an alpine lake in sub-arctic Sweden, Lake Ånn. The genetic diversity of the three species was similar and sufficiently high from a conservation genetics perspective: corrected total heterozygosity, H’T = 0.54, 0.66, 0.60 and allelic richness, AR = 4.93, 5.53 and 5.26 for Arctic charr, brown trout and brook charr, respectively. There were indications of elevated inbreeding coefficients in brown trout (GIS = 0.144) and brook charr (GIS = 0.129) although sibling relationships were likely a confounding factor, as a high proportion of siblings were observed in all species within and among sampling locations. Overall genetic structure differed between species, Fst = 0.01, 0.02 and 0.04 in Arctic charr, brown trout and brook charr respectively, and there was differentiation at only a few specific locations. There was clear evidence of hybridisation between the native Arctic charr and the introduced brook charr, with 6% of individuals being hybrids, all of which were sampled in tributary streams. The ecological and evolutionary consequences of the observed hybridisation are priorities for further research and the conservation of the evolutionary potential of native salmonid species. PMID:27032100

  16. A genetic basis for the phenotypic differentiation between siscowet and lean lake trout (Salvelinus namaycush) [

    Lifescience Database Archive (English)

    Full Text Available Study Type Sample Organism Sequencing Platform Other Salvelinus namaycush 454 GS FLX Article Sum ... he phenotypic differentiation between siscowet and lean ... lake trout (Salvelinus namaycush). Goetz Frederick ... ncipal forms of lake trout (Salvelinus namaycush): lean , siscowet and humper. Wild lean ... and siscowet diffe ...

  17. KAYNAK ALABALIĞI (SALVELINUS FONTINALIS)’NIN SPERMATOLOJİK ÖZELLİKLERİ VE SPERMANIN KISA SÜRELİ MUHAFAZASI

    OpenAIRE

    Şahin, Temel; Köse, Özay

    2015-01-01

    This study was carried out to determine the spermatologic characteristics and to develop an extender for the short-term storage of semen from brook trout. Four different extenders were tested in the study: a) 8.75 g/l NaCl, 0.20 g/l KCl, 0.20 CaCl2, 0.30 g/l NaHCO3 (S1), b) 8.75 g/l NaCl, 0.20 g/l KCl, 0.20 MgCl2, 0.40 g/l NaHCO3 (S2), c) 7.25 g/l NaCl, 0.40 g/l KCl, 0.80 g/l NaHCO3, 2.0 g/l glucose (S3), d) 8.75 g/l NaCl, 0.20 g/l KCl, 0.10 CaCl2, 0.10 g/l MgCl2, 0.40 g/l NaHCO3 (S4). In the...

  18. Ecology and impacts of nonnative salmonids with special reference to brook trout (Salvelinus fontinalis Mitchill) in North Europe

    OpenAIRE

    Korsu, K. (Kai)

    2008-01-01

    Abstract My main objectives in this thesis were to explore general patterns and mechanisms driving salmonid invasions globally and, more specifically, to examine the invasion dynamics and impacts of the North American brook trout in North European stream systems. Non-native salmonids have often spread extensively and caused many harmful impacts on their native counterparts. Among the three globally introduced salmonids, the European brown trout appeared as the 'worst' alien species (st...

  19. 患病北极红点鲑的病原分离与鉴定%Isolation and Identification of Causative Agents of Sick Arctic Charr (Salvelinus alpinus)

    Institute of Scientific and Technical Information of China (English)

    史秀杰; 刘荭; 高隆英; 何俊强; 江育林

    2007-01-01

    对2004年5月四川省某养殖基地养殖的北极红点鲑患病鲑进行了病理学检查和病原分离,从病灶处分离到细菌和真菌.分离到的细菌经API生化鉴定为杀鲑气单胞菌杀鲑亚种(Aeromonas salmonicida subsp.salmonicida).用引物AP1和AP2对纯化后的细菌进行PCR扩增,结果扩增出长度为421 bp的DNA片段,对扩增片段进行克隆、测序,用NCBI-BLASTn在GenBank中搜寻相似序列,结果与杀鲑气单胞菌各株A层蛋白部分编码基因有99%以上的序列同源性.用引物EUS-F和EUS-R对分离到的真菌进行PCR扩增,结果扩增出长度为755 bp的DNA片段,对扩增片段进行克隆、测序,用NCBI-BLASTn在GenBank中搜寻相似序列,结果与水霉属各株的DNA片段(包括18S核糖体RNA基因部分序列、内转录间隔区1全序列、5.8S核糖体RNA基因全序列、内转录间隔区2全序列和28S核糖体RNA部分序列)有93%~100%的同源性;而与属于丝囊霉菌属的EUS各株相对应的DNA片段仅有60%的序列同源性.因此判定所分离的真菌为水霉.杀鲑气单胞菌是引起疖疮病和溃疡病等病的病原菌,而水霉广泛存在于水中,当鱼受伤后,水霉孢子容易从患病部位侵入鱼体,加重感染.因此判断该病主要是由杀鲑气单胞菌引起,而水霉则引起继发感染.

  20. Fine-scale oscillatory banding in otoliths from arctic charr (Salveninus alpinus) and pike (Esox lucius)

    Energy Technology Data Exchange (ETDEWEB)

    Meldrum, A. [Oak Ridge National Lab., TN (United States); Halden, N.M. [Univ. of Manitoba, Winnipeg (Canada). Dept. of Geological Sciences

    1997-12-31

    Transmission electron microscopy of otoliths from the inner ear of arctic charr and pike has revealed the presence of fine banding on the scale of several nanometers. The thickness of the bands was observed to vary in different portions of the sample, and some areas were not banded. EDS analysis could not detect chemical differences within the bands, but electron diffraction showed that the crystallographic orientation of the bands is related by a lattice mismatch. Previously, banding on the scale of 50 to 100 microns was observed by SEM in otoliths from arctic charr and was attributed to seasonal variations in growth. The fine-scale banding observed in this study, however, is unlikely to represent a daily variation. Electron diffraction from the pike samples shows that the material is composed of CaCO{sub 3} having the both the vaterite and aragonite structure, and hydrous CaCO{sub 3} was also observed. The large-scale banding previously identified by SEM was not observed in the TEM despite attempts to intersect the boundaries of the micron-sized layers. The interaction of the electron beam with the sample material was investigated by conducting several electron-irradiation experiments. The electron beam was observed to interact strongly with the sample and caused the precipitation of cubic CaO from the calcium carbonate matrix. Bright-field imaging showed the development of fine grained ({approximately} 5 nm) randomly oriented crystallites which accumulated with increasing electron dose. These initial results suggest that the precipitation of CaO is not driven by electron-beam beating. Previously, a similar phase-change phenomenon has been observed in hydroxyapatite from dental enamel. Other Ca-bearing biominerals may therefore also be expected to be sensitive to electron irradiation.

  1. The use of the aquatic moss Fontinalis antipyretica L. ex Hedw. as a bioindicator for heavy metals

    International Nuclear Information System (INIS)

    We studied heavy metal stress responses of two Fontinalis species, F. antipyretica and F. dalecarlica, collected from two habitats in Germany and Canada. The capacities of the two species for extracellular adsorption (biosorption) and intracellular uptake (bioaccumulation) of Cadmium (Cd2+) were investigated in the laboratory. Time-dependent Cd2+ adsorption by cell wall and intracellular uptake differed significantly between the two species. These differences were related to the number of Cd2+ binding sites, resulting from differences in leaflet surface and cell wall composition. Glutathione (GSH) levels in response to Cd2+ exposure were monitored over a 10-day period. GSH synthesis differed significantly between the two species. Both Fontinalis species appear to be suitable for heavy metal biomonitoring in aquatic habitats

  2. Expression of miR-199a, lum and ets2 in benthic and pelagic Arctic charr morphs at developmental stage 200τ

    OpenAIRE

    Ligthart, Kate, 1992-

    2014-01-01

    MiRNAs play an important role in development by regulating gene expression. They are recruited to RISC complexes, which bind to target mRNAs. This interaction causes silencing of the target mRNAs by repressing translation or by initiating degradation. In lake Þingvallavatn there are four morphs of Arctic charr that are very different in morphology and their feeding apparatus. The different morphs of Arctic charr have different levels of miRNA gene expression during their embryonic development...

  3. Sprint swimming performance of wild bull trout (Salvelinus confluentus)

    Science.gov (United States)

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

    2008-01-01

    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.

  4. The use of aquatic moss (Fontinalis antipyretica as monitor of contamination in standing and running waters: limits and advantages

    Directory of Open Access Journals (Sweden)

    Roberto M. CENCI

    2001-09-01

    Full Text Available The aim of this work is to verify whether water moss (Fontinalis antipyretica could be used as a monitor of trace element contamination in lotic and lentic waters. The investigation was split up the into three sequential experimental trials. 1 Experiments have been set up in lab in order to evaluate the amount of trace elements (Cd, Pb, Cr, Cu and Hg released by moss during a period of 133 days, under controlled chemical-physical conditions. A release of 64% of Hg, 83% of Cr and 70% of Pb was found, whereas no re lease of Cd and Cu has been observed. 2 Clean moss has successively treated with running water at different pH and then treaded with Cu, Cr, Hg and Pb, in order to evaluate the dynamics of accumulation of trace elements in moss. Specifically, three basins containing 100 liters of Lake Maggiore water were equipped with three distinct pumps (15 l min-1 each ensuring the water circulation into a glass tube were arranged. Afterwards, 105 thallus, equivalent to 4.5 g of Fontinalis antipyretica, were fixed into each glass tube. The accumulation dynamics was calculated by collecting moss and water at the beginning, after 1 h, 6 h, 1 day, 4, 9, 14 and 28 days of the experiment. Results showed that the metals accumulation was significant during the first hour. 3 Samples of clean moss were placed in situ. Nine sites in Lake Orta, characterized by high contents of elements due to the anthropic activities, the Toce River and other minor rivers, have been chosen in order to estimate the ability of moss to accumulate Cu, Cr, Pb and Hg from water, and to localize the metal pollution sources. In three sites the Cu average concentration in Fontinalis antipyretica increased from 167 mg kg-1 dry moss to 2100 mg kg-1 after 14 days and to 2900 mg kg-1 after 28 days. A marked accumulation of Hg was observed in Fontinalis antipyretica located in site no 6 (from an initial concentration of 0.2 mg kg-1 dry moss to 17.7 mg kg-1 after 14 days, and 24.6 mg kg-1

  5. Techniques for Functional Testing of Factors Associated with Arctic charr Polymorphism: phenotypic analysis in zebrafish and in vitro assays in cell culture

    OpenAIRE

    O'Sullivan, Freya Mae, 1996-

    2016-01-01

    Trophic morphology in Teleosts, including the jaw and pharyngeal arches, determines feeding type and performance. Polymorphism in trophic morphology facilitates niche partitioning and the coexistence of morphs within ecosystems. In Lake Thingvallavatn, Iceland, Arctic charr displays four morphs, two benthic; small (SB) and large (LB), and two pelagic; piscivorous (PI) and planktivorous (PL). These ecomorphs show disparity in behaviour, morphology and feeding type, as well as variation in gene...

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

    OpenAIRE

    Teachout, Emily; Quan, Jennifer

    2001-01-01

    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...

  7. Complete mitochondrial genome of the white char Salvelinus albus (Salmoniformes, Salmonidae).

    Science.gov (United States)

    Balakirev, Evgeniy S; Parensky, Valery A; Kovalev, Mikhail Yu; Ayala, Francisco J

    2016-09-01

    The complete mitochondrial genome was sequenced in two individuals of white char Salvelinus albus. The genome sequences are 16 653 bp in size, and the gene arrangement, composition, and size are very similar to the salmonid fish genomes published previously. The low level of sequence divergence detected between the genome of S. albus and the GenBank complete mitochondrial genomes of the Northern Dolly Varden char S. malma (KJ746618) and the Arctic char S. alpinus (AF154851) may likely be due to recent divergence of the species and/or historical hybridization and interspecific replacement of mtDNA. PMID:26358825

  8. Trace elements in the Fontinalis antipyretica from rivers receiving sewage of lignite and glass sand mining industry.

    Science.gov (United States)

    Kosior, Grzegorz; Samecka-Cymerman, Aleksandra; Kolon, Krzysztof; Brudzińska-Kosior, Anna; Bena, Waldemar; Kempers, Alexander J

    2015-07-01

    Intensive lignite and glass sand mining and industrial processing release waste which may contain elements hazardous to the aquatic ecosystem and constitute a potential risk to human health. Therefore, their levels must be carefully controlled. As a result, we examined the effects of sewage on the aquatic Fontinalis antipyretica moss in the Nysa Łużycka (lignite industry) and the Kwisa Rivers (glass sand industry). The Nysa Łużycka and the Kwisa Rivers appeared to be heavily polluted with As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V and Zn, which were reflected in the extremely high concentration of these elements in F. antipyretica along the studied watercourses. In the Nysa Łużycka, trace element composition in the moss species is affected by lignite industry with accumulation in its tissues of the highest concentrations of Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn, while samples from the Kwisa sites influenced by glass sand industry revealed the highest concentrations of As, V and Fe. The principal component and classification analysis classifies the concentration of elements in the aquatic F. antipyretica moss, thus enabling the differentiation of sources of water pollution in areas affected by mining industry. PMID:25647494

  9. Embryonic developmental progression in lake trout (Salvelinus namaycush) (Walbaum, 1792) and its relation to lake temperature

    Science.gov (United States)

    Allen, Jeffrey D.; Walker, Glenn K.; Adams, Jean V.; Nichols, S. Jerrine; Edsall, Carol C.

    2005-01-01

    Developmental progression of lake trout (Salvelinus namaycush) embryos was examined with light and scanning electron microscopy. From this examination, key developmental stages were described in detail. The key developmental stages were then applied to individual lake trout egg lots incubated in constant temperatures of 2, 4, 6, 8, and 10°C. We used Belehradek's, Thermodynamic, and Power models, and also developed the Zero model to determine stage specific developmental rates of lake trout eggs for each background temperature. From the models, hatch dates and staging were predicted for temperature regimes from Lake Superior (1990–91) and Lake Huron (1996–97). Based on the existing lake temperature data and the observed spawning dates, the Zero and the Power models predict that post peak spawning may contribute significantly to overall recruitment success for these years.

  10. Effects of the introduction of Lake Trout (Salvelinus Namaycush) on the Osprey (Pandion Haliaetus) population in Yellowstone National Park

    OpenAIRE

    Søyland, Anders

    2011-01-01

    In recent years the number and reproduction of ospreys (Pandion haliaetus) nesting on Yellowstone Lake in Yellowstone National Park (YNP), USA, has been declining. The main hypothesis is that the decline in nesting ospreys is due to the introduction of the lake trout (Salvelinus namaycush), which is believed to have reduced the cutthroat trout (Oncorhynchus clarki bouvieri) population in Yellowstone Lake substantially. The lake trout inhabit deeper water range than the cutthroat and is theref...

  11. Relative sensitivity of bull trout (Salvelinus confluentus) and rainbow trout (Oncorhynchus mykiss) to acute copper toxicity.

    Science.gov (United States)

    Hansen, James A; Lipton, Josh; Welsh, Paul G

    2002-03-01

    Bull trout (Salvelinus confluentus) were recently listed as threatened in the United States under the federal Endangered Species Act. Past and present habitat for this species includes waterways contaminated with heavy metals released from mining activities. Because the sensitivity of this species to copper was previously unknown, we conducted acute copper toxicity tests with bull and rainbow trout (Oncorhynchus mykiss) in side-by-side comparison tests. Bioassays were conducted using water at two temperatures (8 degrees C and 16 degrees C) and two hardness levels (100 and 220 mg/L as CaCO3). At a water hardness of 100 mg/L, both species were less sensitive to copper when tested at 16 degrees C compared to 8 degrees C. The two species had similar sensitivity to copper in 100-mg/ L hardness water, but bull trout were 2.5 to 4 times less sensitive than rainbow trout in 220-mg/L hardness water. However, when our results were viewed in the context of the broader literature on rainbow trout sensitivity to copper, the sensitivities of the two species appeared similar. This suggests that adoption of toxicity thresholds that are protective of rainbow trout would be protective of bull trout; however, an additional safety factor may be warranted because of the additional level of protection necessary for this federally threatened species. PMID:11878477

  12. Dwarf char, a new form of chars (the genus Salvelinus) in Lake Kronotskoe

    Science.gov (United States)

    Pavlov, S.D.; Pivovarov, E.A.; Ostberg, C.O.

    2012-01-01

    Lake Kronotskoe is situated in the Kronotskii State Nature Reserve and is a unique natural heritage of Kamchatka. The lake–river system of the reserve includes numerous springs and small streams and three large inflowing rivers, Listvennichnaya, Unana, and Uzon, which form the main bays of Lake Kronotskoe; one river (Kronotskaya) flows from the lake. This river is characterized by several rapids, which are assumed to be unsurmountable barriers for fish migration. The ichthyofauna of the lake has been isolated for a long time, and some endemic fishes appeared, including char of the genus Salvelinus and the residential form of red salmon Oncorhynchus nerka (the local name is kokanee). These species are perfect model objects to study microevolution processes. Char of Lake Kronotskoe are characterized by significant polymorphism and plasticity [1–3]; therefore, they are extremely valuable for studying the processes of speciation and form development. That is why the populations of char in Lake Kronotskoe are unique and attract special attention of researchers. 

  13. Bioacumulação de poluentes metálicos (CD2+) por briófitas aquáticas fontinalis antipyretica

    OpenAIRE

    Martins, Ramiro; Boaventura, Rui

    2006-01-01

    O objectivo deste trabalho é compreender em termos quantitativos e qualitativos a acumulação e libertação de Cd(II) em solução aquosa, por uma briófita aquática - Fontinalis antipyretica – na perspectiva duma aplicação quer na biomonitorização de cursos de água, quer na descontaminação de efluentes industriais. A acumulação de cádmio e posterior eliminação pelo musgo foi estudada em laboratório expondo as plantas a diferentes concentrações de cádmio na gama, 0,5 – 2,5 mg l-1, durante um perío...

  14. Modelling the extra and intracellular uptake and discharge of heavy metals in Fontinalis antipyretica transplanted along a heavy metal and pH contamination gradient

    International Nuclear Information System (INIS)

    Samples of the aquatic bryophyte Fontinalis antipyretica Hedw. were transplanted to different sites with the aim of characterizing the kinetics of the uptake and discharge of heavy metals in the extra and intracellular compartments. The accumulation of metals in extracellular compartments, characterized by an initial rapid accumulation, then a gradual slowing down over time, fitted perfectly to a Michaelis-Menten model. The discharge of metals from the same compartment followed an inverse linear model or an inverse Michaelis-Menten model, depending on the metal. In intracellular sites both uptake and discharge occurred more slowly and progressively, following a linear model. We also observed that the acidity of the environment greatly affected metal accumulation in extracellular sites, even when the metals were present at relatively high concentrations, whereas the uptake of metals within cells was much less affected by pH. - The kinetics of uptake and discharge of heavy metals, in different cellular locations, were studied in transplanted aquatic mosses

  15. 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)

    Data.gov (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...

  16. β-N-Methylamino-L-alanine exposure alters defense against oxidative stress in aquatic plants Lomariopsis lineata, Fontinalis antipyretica, Riccia fluitans and Taxiphyllum barbieri.

    Science.gov (United States)

    Contardo-Jara, Valeska; Funke, Marc Sebastian; Peuthert, Anja; Pflugmacher, Stephan

    2013-02-01

    Four different aquatic plants, the Pteridophyte Lomariopsis lineata and the Bryophytes Fontinalis antipyretica, Riccia fluitans and Taxiphyllum barbieri, were tested for their capacity to absorb the neurotoxin β-N-Methylamino-L-alanine (BMAA) from water and thus their possible applicability in a "Green Liver System". After exposure to 10 and 100 μg L(-1) BMAA for 1, 3, 7 and 14 days exposure concentration of medium and tissue were analyzed by LC-MS/MS. The amount removed by the plants within only 1 day was equal to the biological degradation of 14 days. Comparing the "BMAA-removal" capacity of the 4 tested aquatic plants R. fluitans, L. lineata and T. barbieri turned out to be most effective in cleaning the water from this cyanobacterial toxin by up to 97% within 14 days. Activity of the antioxidant enzymes peroxidase (POD) and catalase (CAT), as well as biotransformation enzyme glutathione S-transferase (GST) was compared between exposed and control plants to determine possible harmful effects induced by BMAA. Whereas the Bryophytes displayed increased POD activity and subsequent adaptation when exposed to the lower concentration, as well as partly inhibited antioxidant response at the higher applied BMAA concentration, the Pteridophyte L. lineata reacted with increased POD activity during the whole experiment and increased GST activity after longer exposure for 14 days. To give a recommendation of the suitability of an aquatic plant to be used for sustainable phytoremediation of contaminated water, testing of removal capacity of specific contaminants as well as studying general physiological parameters giving hint on survivability in such environments has to be combined. PMID:23177931

  17. ACUTE AND CHRONIC TOXICITY OF CHLORDANE TO FISH AND INVERTEBRATES

    Science.gov (United States)

    The acute and chronic toxicity of technical chlordane to bluegill (Lepomis macrochirus), fathead minnow (Pimephales promelas), brook trout (Salvelinus fontinalis), Daphnia magna, Hyallela azteca, and Chironomus No. 51 were determined with flow-through conditions. The purpose was ...

  18. Great Smoky Mountains National Park Fish Distribution

    Data.gov (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...

  19. Environmental contaminants in brook trout from Aroostook National Wildlife Refuge

    Data.gov (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...

  20. Seasonal Variations in Relative Weight of Lake Trout (Salvelinus namaycush), Kokanee Salmon (Oncorhynchus nerka), Rainbow Trout (Onocorhynchus mykiss), and Brown Trout (Salmo trutta) in Blue Mesa Reservoir, Colorado

    OpenAIRE

    Midas, Madeline; Williams, Asia; Cooper, Cindy; Courtney, Michael

    2013-01-01

    Blue Mesa Reservoir is the largest body of water in Colorado and is located on the western slope of the Rocky Mountains at an elevation of 7520 feet. Blue Mesa Reservoir contains recreationally important populations of lake trout (Salvelinus namaycush), kokanee salmon (Oncorhynchus nerka), rainbow trout (Onocorhynchus mykiss), and brown trout (Salmo trutta). A management challenge in recent years has been the overpopulation of lake trout, which has led to a steep decline in abundance of kokan...

  1. Arctic char - friend or foe?: Climate driven seasonal variation in competitive impact of Arcticchar (Salvelinus alpinus L) on brown trout (Salmo truttaence L)

    OpenAIRE

    Ulvan, Eva Marita

    2010-01-01

    Here I test for climate driven seasonal effects on competition in lakes using brown trout (Salmo trutta L.) and Arctic char (Salvelinus alpinus L.) as model organisms. Winter and summer brown trout consumption rates were estimated by 1374 Cs tracer methodology using brown trout sampled in  allopatric (brown trout) and 10 sympatric (brown trout/Arctic char) lakes, located along an altitudinal gradient in central Scandinavia. Lake catchment area  vegetation properties ranged from southern borea...

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

    Directory of Open Access Journals (Sweden)

    Rene Dion

    2006-12-01

    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

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

    Science.gov (United States)

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

    2016-05-01

    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. PMID:26986088

  4. Evidence of widespread natural reproduction by lake trout Salvelinus namaycush in the Michigan waters of Lake Huron

    Science.gov (United States)

    Riley, S.C.; He, J.X.; Johnson, J.E.; O'Brien, T. P.; Schaeffer, J.S.

    2007-01-01

    Localized natural reproduction of lake trout Salvelinus namaycush in Lake Huron has occurred since the 1980s near Thunder Bay, Michigan. During 2004–2006, USGS spring and fall bottom trawl surveys captured 63 wild juvenile lake trout at depths ranging from 37–73 m at four of five ports in the Michigan waters of the main basin of Lake Huron, more than five times the total number captured in the previous 30-year history of the surveys. Relatively high catches of wild juvenile lake trout in bottom trawls during 2004–2006 suggest that natural reproduction by lake trout has increased and occurred throughout the Michigan waters of the main basin. Increased catches of wild juvenile lake trout in the USGS fall bottom trawl survey were coincident with a drastic decline in alewife abundance, but data were insufficient to determine what mechanism may be responsible for increased natural reproduction by lake trout. We recommend further monitoring of juvenile lake trout abundance and research into early life history of lake trout in Lake Huron.

  5. Paenibacillus thiaminolyticus is not the cause of thiamine deficiency impeding lake trout (Salvelinus namaycush) recruitment in the Great Lakes

    Science.gov (United States)

    Richter, Catherine A.; Evans, Allison N.; Wright-Osment, Maureen K.; Zajicek, James L.; Heppell, Scott A.; Riley, Stephen C.; Krueger, Charles C.; Tillitt, Donald E.

    2012-01-01

    Thiamine (vitamin B1) deficiency is a global concern affecting wildlife, livestock, and humans. In Great Lakes salmonines, thiamine deficiency causes embryo mortality and is an impediment to restoration of native lake trout (Salvelinus namaycush) stocks. Thiamine deficiency in fish may result from a diet of prey with high levels of thiaminase I. The discoveries that the bacterial species Paenibacillus thiaminolyticus produces thiaminase I, is found in viscera of thiaminase-containing prey fish, and causes mortality when fed to lake trout in the laboratory provided circumstantial evidence implicating P. thiaminolyticus. This study quantified the contribution of P. thiaminolyticus to the total thiaminase I activity in multiple trophic levels of Great Lakes food webs. Unexpectedly, no relationship between thiaminase activity and either the amount of P. thiaminolyticus thiaminase I protein or the abundance of P. thiaminolyticus cells was found. These results demonstrate that P. thiaminolyticus is not the primary source of thiaminase activity affecting Great Lakes salmonines and calls into question the long-standing assumption that P. thiaminolyticus is the source of thiaminase in other wild and domestic animals.

  6. Micro-PIXE analysis of strontium in Arctic char, Salvelinus alpinus, otoliths from Quttinirpaaq National Park, Nunavut, Canada

    International Nuclear Information System (INIS)

    Arctic char, Salvelinus alpinus, exhibit either lake resident or anadromous (sea-run) life histories. Anadromy is less prevalent at the northern and southern extremes of the distribution. Effective conservation and management of char requires knowledge of life histories exhibited by individuals and populations. Micro-PIXE line-scans were used to determine the distribution of strontium (Sr) in otoliths from which life history patterns were determined for Arctic char from 10 lakes in Quttinirpaaq National Park in the Canadian High Arctic. Although most populations were lake resident as expected, the data indicated that a component of the char population from one lake was anadromous. This represents the most northerly known char population to exhibit anadromy. Mean Sr concentrations in otoliths of char from all populations, as determined by point analysis and also from line-scan data, showed no significant differences between the methods. Mean Sr concentrations (from point analysis) showed significant differences between some of the populations. These differences combined with other analyses (e.g. morphometrics, genetics) can be used to differentiate biological populations. Thus, micro-PIXE analysis is a useful tool for assessing diversity in Arctic char and contributing to their management and conservation in the park

  7. Network analysis highlights complex interactions between pathogen, host and commensal microbiota.

    Directory of Open Access Journals (Sweden)

    Sébastien Boutin

    Full Text Available Interactions between bacteria and their host represent a full continuum from pathogenicity to mutualism. From an evolutionary perspective, host-bacteria relationships are no longer considered a two-component system but rather a complex network. In this study, we focused on the relationship between brook charr (Salvelinus fontinalis and bacterial communities developing on skin mucus. We hypothesized that stressful conditions such as those occurring in aquaculture production induce shifts in the bacterial community of healthy fish, thus allowing pathogens to cause infections. The results showed that fish skin mucus microbiota taxonomical structure is highly specific, its diversity being partly influenced by the surrounding water bacterial community. Two types of taxonomic co-variation patterns emerged across 121 contrasted communities' samples: one encompassing four genera well known for their probiotic properties, the other harboring five genera mostly associated with pathogen species. The homeostasis of fish bacterial community was extensively disturbed by induction of physiological stress in that both: 1 the abundance of probiotic-like bacteria decreased after stress exposure; and 2 pathogenic bacteria increased following stress exposure. This study provides further insights regarding the role of mutualistic bacteria as a primary host protection barrier.

  8. Evolution and origin of sympatric shallow-water morphotypes of Lake Trout, Salvelinus namaycush, in Canada's Great Bear Lake.

    Science.gov (United States)

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

    2015-01-01

    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. PMID:25204304

  9. Effects of coancestry on accuracy of individual assignments to population of origin: examples using Great Lakes lake trout (Salvelinus namaycush).

    Science.gov (United States)

    Guinand, Bruno; Scribner, Kim T; Page, Kevin S; Filcek, Kristi; Main, Laura; Burnham-Curtis, Mary K

    2006-05-01

    Methods for assigning individuals to population of origin are widely used in ecological genetics, resources management, and forensics. Characteristics of genetic data obtained from putative source populations that enhance accuracy of assignment are well established. How non-independence within and among unknown individuals to be classified [i.e., gene correlations within individual (inbreeding) and gene correlations among individuals within group (coancestry)] affect assignment accuracy is poorly understood. We used empirical data for six microsatellite loci and offspring from full-sib crosses of hatchery strains of lake trout (Salvelinus namaycush; Salmonidae) representing known levels of coancestry (mean theta = 0.006 and 0.06) within families to investigate how gene correlations can affect assignment. Additional simulations were conducted to further investigating the influence of allelic diversity (2, 6 or 10 alleles per locus) and inbreeding (F = 0.00, 0.05, and 0.15) on assignment accuracy for cases of low and high inter-population variance in allele frequency (mean F (st) = 0.01 and 0.1, respectively). Inbreeding had no effect on accuracy of assignments. In contrast, variance in assignment accuracy across replicated simulations, and for each empirical case study increased with increasing coancestry, reflecting non-independence of probabilities of correct assignment among members of kin groups. Empirical estimates of assignment error rates should be interpreted with caution if appreciable levels of coancestry are suspected. Additional emphasis should be placed on sampling designs (spatially and temporally) that define or minimize the potential for sampling related individuals. PMID:16850237

  10. Laboratory Estimation of Net Trophic Transfer Efficiencies of PCB Congeners to Lake Trout (Salvelinus namaycush) from Its Prey

    Science.gov (United States)

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

    2014-01-01

    A technique for laboratory estimation of net trophic transfer efficiency (γ) of polychlorinated biphenyl (PCB) congeners to piscivorous fish from their prey is described herein. During a 135-day laboratory experiment, we fed bloater (Coregonus hoyi) that had been caught in Lake Michigan to lake trout (Salvelinus namaycush) kept in eight laboratory tanks. Bloater is a natural prey for lake trout. In four of the tanks, a relatively high flow rate was used to ensure relatively high activity by the lake trout, whereas a low flow rate was used in the other four tanks, allowing for low lake trout activity. On a tank-by-tank basis, the amount of food eaten by the lake trout on each day of the experiment was recorded. Each lake trout was weighed at the start and end of the experiment. Four to nine lake trout from each of the eight tanks were sacrificed at the start of the experiment, and all 10 lake trout remaining in each of the tanks were euthanized at the end of the experiment. We determined concentrations of 75 PCB congeners in the lake trout at the start of the experiment, in the lake trout at the end of the experiment, and in bloaters fed to the lake trout during the experiment. Based on these measurements, γ was calculated for each of 75 PCB congeners in each of the eight tanks. Mean γ was calculated for each of the 75 PCB congeners for both active and inactive lake trout. Because the experiment was replicated in eight tanks, the standard error about mean γ could be estimated. Results from this type of experiment are useful in risk assessment models to predict future risk to humans and wildlife eating contaminated fish under various scenarios of environmental contamination. PMID:25226430

  11. A dynamic-bioenergetics model to assess depth selection and reproductive growth by lake trout (Salvelinus namaycush).

    Science.gov (United States)

    Plumb, John M; Blanchfield, Paul J; Abrahams, Mark V

    2014-06-01

    We coupled dynamic optimization and bioenergetics models to assess the assumption that lake trout (Salvelinus namaycush) depth distribution is structured by temperature, food availability, and predation risk to maximize reproductive mass by autumn spawning. Because the model uses empirical daily thermal-depth profiles recorded in a small boreal shield lake (lake 373 at the Experimental Lakes Area, northwestern Ontario) during 2 years of contrasting thermal stratification patterns, we also assessed how climate-mediated changes in lakes may affect the vertical distribution, growth, and fitness of lake trout, a cold-water top predator. The depths of acoustic-tagged lake trout were recorded concurrently with thermal-depth profiles and were compared to model output, enabling an assessment of model performance in relation to the observed fish behavior and contrasting thermal conditions. The depths and temperatures occupied by simulated fish most closely resembled those of the tagged fish when risk of predation was included in the model, indicating the model may incorporate the most important underlying mechanisms that determine lake trout depth. Annual differences suggest less use of shallow (warm), productive habitats, resulting in markedly less reproductive mass, during the year with the warm stratification pattern. Mass for reproduction may be lower in warmer conditions because of reduced reproductive investment, yet survival may be inadvertently higher because risky surface waters may be avoided more often in warmer, shallower, and metabolically costly conditions. At a minimum our study suggests that lake trout reproductive mass and fitness may be expected to change under the anticipated longer and warmer stratification patterns. PMID:24682254

  12. Fungal and mussel protein sources in fish feed

    OpenAIRE

    Vidaković, Aleksandar

    2015-01-01

    Fungal and mussel protein sources in the diet of Eurasian perch (Perca fluviatilis), Arctic charr (Salvelinus alpinus) and rainbow trout (Oncorhynchus mykiss) and their effect on growth performance, nutrient utilisation, intestinal barrier function and post-prandial profiles of plasma amino acids and whole blood parameters were evaluated in this thesis. Apparent digestibility of dry matter, sum of amino acids and gross energy in experiment with Arctic charr decreased with dietary inclusio...

  13. Extensive feeding on sockeye salmon Oncorhynchus nerka smolts by bull trout Salvelinus confluentus during initial outmigration into a small, unregulated and inland British Columbia river.

    Science.gov (United States)

    Furey, N B; Hinch, S G; Lotto, A G; Beauchamp, D A

    2015-01-01

    Stomach contents were collected and analysed from 22 bull trout Salvelinus confluentus at the edge of the Chilko Lake and Chilko River in British Columbia, Canada, during spring outmigration of sockeye salmon Oncorhynchus nerka smolts. Twenty of the 22 (>90%) stomachs contained prey items, virtually all identifiable prey items were outmigrant O. nerka smolts and stomach contents represented a large portion (0·0-12·6%) of estimated S. confluentus mass. The results demonstrate nearly exclusive and intense feeding by S. confluentus on outmigrant smolts, and support recent telemetry observations of high disappearance rates of O. nerka smolts leaving large natural lake systems prior to entering high-order unregulated river systems. PMID:25494841

  14. Bull Trout (Salvelinus Confluentus) Population and Habitat Surveys in the McKenzie and Middle Fork Willamette Basins, 2000 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Greg

    2000-11-28

    Prior to 1978, Dolly Varden Salvelinus malma were classified into an anadromous and interior form. Cavender (1978) classified the interior form as a distinct species, Salvelinus confluentus, the bull trout. Bull trout are large char weighing up to 18 kg and growing to over one meter in length (Goetz 1989). They are distinguished by a broad flat head, large downward curving maxillaries that extend beyond the eye, a well developed fleshy knob and a notch in the lower terminus of the snout, and light colored spots normally smaller than the pupil of the eye (Cavender 1978). Bull trout are found throughout northwestern North America from lat. 41{sup o}N to lat. 60{sup o}N. In Oregon, bull trout were once distributed throughout 12 basins in the Klamath and Columbia River systems including the Clackamas, Santiam, McKenzie and Middle Fork Willamette sub-basins west of the Cascades (Buchanan et al. 1997). However, it is believed bull trout have been extirpated from west of the Cascades with the exception of the McKenzie sub-basin. Before 1963, bull trout in the McKenzie sub-basin were a contiguous population from the mouth to Tamolitch Falls. Following the construction of Cougar and Trail Bridge Reservoirs there are three isolated populations: (1) mainstem McKenzie and tributaries from the mouth to Trail Bridge Reservoir. (2) mainstem McKenzie and tributaries above Trail Bridge Reservoir to Tamolitch Falls. (3) South Fork McKenzie and tributaries above Cougar Reservoir. The study area includes the three aforementioned McKenzie populations, and the Middle Fork Willamette and tributaries above Hills Creek Reservoir. We monitored bull trout populations in the McKenzie and Middle Fork Willamette basins using a combination of sampling techniques including: spawning surveys, standard pool counts, juvenile trapping, radio tracking, electronic fish counters, and a modified Hankin and Reeves protocol to estimate juvenile abundance and density. In addition, we continued to

  15. Distinguishing wild vs. stocked lake trout (Salvelinus namaycush) in Lake Ontario: Evidence from carbon and oxygen stable isotope values of otoliths

    Science.gov (United States)

    Schaner, T.; Patterson, W.P.; Lantry, B.F.; O'Gorman, R.

    2007-01-01

    We investigated the potential for using carbon and oxygen isotope values of otolith carbonate as a method to distinguish naturally produced (wild) lake trout (Salvelinus namaycush) from hatchery-reared lake trout in Lake Ontario. We determined δ 13C(CaCO3) and δ 18O(CaCO3) values of otoliths from juvenile fish taken from two hatcheries, and of otoliths from wild yearlings. Clear differences in isotope values were observed between the three groups. Subsequently we examined otoliths from large marked and unmarked fish captured in the lake, determining isotope values for regions of the otolith corresponding to the first year of life. Marked (i.e., stocked) fish showed isotope ratios similar to one of the hatchery groups, whereas unmarked fish, (wild fish or stocked fish that lost the mark) showed isotope ratios similar either to one of the hatchery groups or to the wild group. We interpret these data to suggest that carbon and oxygen isotope values can be used to determine the origin of lake trout in Lake Ontario, if a catalogue of characteristic isotope values from all candidate years and hatcheries is compiled.

  16. Bull Trout (Salvelinus Confluentus) Population and Habitat Surveys in the McKenzie and Middle Fork Willamette Basins, 2001 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Greg

    2003-02-01

    Prior to 1978, bull trout were commonly known as dolly varden (Salvelinus malma) and were classified into an anadromous and interior form. Cavender (1978) described the interior form as a distinct species, classifying it as Salvelinus confluentus, the bull trout. Bull trout are large char weighing up to 18 kg and growing to over one meter in length (Goetz 1994). They are distinguished by a broad flat head, large downward curving maxillaries that extend beyond the eye, a fleshy knob and a notch in the lower terminus of the snout, and light colored spots normally smaller than the pupil of the eye (Cavender 1978). Bull trout are found throughout northwestern North America from latitude 41{sup o}N to 60{sup o}N. In Oregon, bull trout were once distributed throughout 12 basins in the Klamath and Columbia River systems including the Clackamas, Santiam, McKenzie and Middle Fork Willamette subbasins west of the Cascades (Buchanan et al. 1997). However, it is likely that bull trout have been extirpated from west of the Cascades with the exception of the McKenzie sub-basin. McKenzie River bull trout were a contiguous population from the mouth to Tamolitch Falls prior to 1963. Three populations were isolated following the construction of Cougar and Trail Bridge Reservoirs which include the mainstem McKenzie and tributaries from the mouth to Trail Bridge Reservoir, mainstem McKenzie and tributaries above Trail Bridge Reservoir to Tamolitch Falls, and the South Fork McKenzie and tributaries above Cougar Reservoir. On June 10, 1998 the U.S. Fish and Wildlife Service (USFWS) listed the Columbia River bull trout population segment as Threatened under the federal Endangered Species Act and Buchanan et al. (1997) listed the bull trout population in the mainstem McKenzie as ''of special concern'', the South Fork McKenzie population as ''high risk of extinction,'' and the population above Trail Bridge Reservoir as ''high risk of

  17. 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.

    1995-01-01

    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.

  18. 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)

    Science.gov (United States)

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

    2009-01-01

    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.

  19. Investigations of bull trout (Salvelinus confluentus), steelhead trout (Oncorhynchus mykiss), and spring chinook salmon (O. tshawytscha) interactions in Southeast Washington streams. Final report 1992; FINAL

    International Nuclear Information System (INIS)

    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

  20. Investigations of bull trout (Salvelinus confluentus), steelhead trout (Oncorhynchus mykiss), and spring chinook salmon (O. tshawytscha) interactions in Southeast Washington streams. Final report 1992

    International Nuclear Information System (INIS)

    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

  1. 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

    Science.gov (United States)

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

    2012-01-01

    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.

  2. 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.

    1992-07-01

    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

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

    OpenAIRE

    Egeland, Torvald B.; Rudolfsen, Geir; Nordeide, Jarle T.; Folstad, Ivar

    2015-01-01

    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 male...

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

    OpenAIRE

    Torvald Blikra Egeland; Geir eRudolfsen; Jarle Tryti Nordeide; Ivar eFolstad

    2015-01-01

    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 ...

  5. Caractérisation de l'adaptation comportementale des téléostéens en élevage : plasticité et effets de la domestication

    OpenAIRE

    Benhaïm, David

    2011-01-01

    The present work aims at a better understanding of the adaptation to farming conditions through a behavioural approach based on the comparison between wild vs. domesticated populations of three species: a marine species, sea bass (Dicentrarchus labrax), two freshwater species, arctic charr (Salvelinus alpinus) and brown trout (Salmo trutta). The thesis is divided into two parts which objectives were : 1) to test the impact of biotic and abiotic factors selected based on their importance in aq...

  6. Fine-scale behavioural differences distinguish resource use by ecomorphs in a closed ecosystem

    OpenAIRE

    Hawley, Kate L.; Carolyn M. Rosten; Guttorm Christensen; Martyn C. Lucas

    2016-01-01

    Temporal differences in habitat use and foraging specialisms between ecomorphs represent aspects of behavioural phenotype that are poorly understood with regard to the origin and maintenance of ecological diversity. We tested the role of behaviour in resource use divergence of two Arctic charr (Salvelinus alpinus) phenotypes, a slim, putatively pelagic-dwelling morph and a robust, putatively littoral-dwelling generalist morph, over an annual cycle, using biotelemetry and stable isotopes. Pela...

  7. Spatial and temporal variations in parasite communities of freshwater fish in the subarctic

    OpenAIRE

    Kuhn, Jesper Andreas

    2015-01-01

    Parasite communities are complicated systems believed to be affected by multiple ecological and environmental factors, both in time and space. These communities might be disrupted by anthropogenic host introductions which unfortunately appear to be a common practice e.g. in freshwater fish management. By addressing parasite occurrences in three of the most common freshwater fish species in subarctic lakes of Northern Europe; brown trout (Salmo trutta), Arctic charr (Salvelinus alpinus) and th...

  8. An Evaluation of the Relative Performance of Diploid Versus Triploid Brook Trout with Consideration of the Influence of Lake Characteristics

    OpenAIRE

    Dean, Andy

    2014-01-01

    Triploid (sterile) trout potentially offer a more risk-averse option for stocking popular non-native sport fish; however the relative performance (e.g., survival and growth) of triploid versus diploid fish in natural settings is not well understood. I evaluated the relative performance of triploid versus diploid brook trout (Salvelinus fontinalis) stocked in high mountain Uinta lakes in response to food availability and lake morphology. I chose a set of 9 lakes that included a range of elevat...

  9. Movement Patterns and Multi-Scale Factors That Influence Exotic Brook Trout And Endemic Bonneville Cutthroat Trout Distribution And Abundance In The Mill Creek Drainage, Utah

    OpenAIRE

    Nadolski, Benjamin Keith

    2008-01-01

    Introduced brook trout (Salvelinus fontinalis) are implicated as a primary factor leading to the decline in distribution and abundance of native cutthroat trout (Oncorhynchus clarkii). However, not all introductions are successful, suggesting local conditions influence the success of invasions. Therefore, I sought to determine the multi-scale factor(s) that influence brook trouts’ invasion success of native Bonneville cutthroat trout (Oncorhynchus clarkii utah) habitats in Mill Creek, Utah. I...

  10. Do native brown trout and non-native brook trout interact reproductively?

    OpenAIRE

    Cucherousset, Julien; Aymes, J.-C.; Poulet, Nicolas; Santoul, Frédéric; Céréghino, Régis

    2008-01-01

    International audience Reproductive interactions between native and non-native species of fish have received little attention compared to other types of interactions such as predation or competition for food and habitat. We studied the reproductive interactions between non-native brook trout (Salvelinus fontinalis) and native brown trout (Salmo trutta) in a Pyrenees Mountain stream (SW France). We found evidence of significant interspecific interactions owing to consistent spatial and temp...

  11. Movement and Habitat Use of Bonneville Cutthroat Trout (Oncorhynchus Clarki Utah): A Case Study In the Temple Fork Watershed

    OpenAIRE

    Lokteff, Ryan L.

    2014-01-01

    Movement patterns and habitat use of Bonneville cutthroat trout (Oncorhynchus clarki utah) in tributaries of the Logan River watershed are greatly aected by habitat alterations created by North American Beaver (Castor canadensis). Evaluation of cutthroat trout habitat use in these watersheds is also complicated by biotic interactions with invasive brown trout (Salmo trutta) and brook trout (Salvelinus fontinalis). My objectives in this thesis were to 1.) Evaluate the passage of beaver dams by...

  12. Flodpärlmusslans status i Laxtjärnbäcken : Effekter på flodpärlmusslan av sedimentbelastning och förekomst av bäckröding

    OpenAIRE

    Pålsson, Anders

    2011-01-01

    The aim of this present study was to determine and evaluate whether the presence of brooktrout (Salvelinus fontinalis) and sediment load may be a threat against the reproduction anddistribution of freshwater pearl mussel (Margaritifera margaritifera) in a creek located innorthern Sweden. Freshwater pearl mussel is an endangered species and is dependent ofbrown trout (Salmo trutta) to reproduce. Therefore there are concerns of indirect effects onthe population of pearl mussel by competition be...

  13. The Movements of Ferox Trout, Salmo trutta, in a Scottish Highland Freshwater Loch

    OpenAIRE

    Thorne, Alastair; MacDonald, Alisdair; Thorley, Joseph; Johnstone, Alastair

    2015-01-01

    Ferox trout (Salmo trutta) are the top fish predators in many Scottish lochs feeding on smaller trout and Arctic charr (Salvelinus alpinus) – their main prey species. Although once considered a separate species, ferox trout are brown trout which have switched to a mainly piscivorous diet. The diet switch not only boosts growth (the current UK rod caught record weight is 14.4kg), but also adds to longevity (the oldest confirmed UK ferox was 23 years old). The main aim of the study d...

  14. Lake bathymetry and species occurrence predict the distribution of a lacustrine apex predator.

    Science.gov (United States)

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

    2016-04-01

    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. PMID:26899559

  15. 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: yoshi887@ffpri.affrc.go.jp [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)

    2014-06-01

    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.

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

    International Nuclear Information System (INIS)

    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 (137Cs) in brown trout (Salmo trutta) than in rainbow trout (Oncorhynchus nerka), and 137Cs 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 (137Cs) 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 137Cs in brown trout was higher than in rainbow trout. • 137Cs concentration of brown trout in a lake was higher than in a stream. • 137Cs concentration of stream charr was higher in region with higher aerial activity. • Concentration of 137Cs in stream charr was higher in older fish. • Difference of contamination among fishes was due to difference in diet and habitat

  17. Dicty_cDB: Contig-U11906-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available lis cyclo-oxygenase 2 ... 70 2e-10 AY606270_1( AY606270 |pid:none) Macrobrachium rosenbergii peroxine......up chromosome 3 clone OS... 46 5.5 1 ( AC125784 ) Genomic sequence for Oryza sativa, Nipponba...as palustris BisB... 135 6e-30 CP001298_1859( CP001298 |pid:none) Methylobacterium chlorome...... 88 1e-15 CU458896_3880( CU458896 |pid:none) Mycobacterium abscessus chromos... 87 2e-15 EU677754_1( EU677754 |pid:non...e) Salvelinus fontinalis prostaglandi... 78 1e-12 CP001341_2833( CP001341 |pid:none) Arthrobacter chloro

  18. Vliv alternativních krmiv na růst, výtěžnost a senzorické vlastnosti masa lososovitých ryb.

    OpenAIRE

    PFLUG, Róbert

    2013-01-01

    The bachelor thesis evaluates the impact of alternative feed on growth, yield and sensory evaluation of flesh of salmonids. The technology "finishing feeding" and its impact on these indicators was evaluated by a feeding test conducted in trout farm in Annin (Klatovské rybářství a.s.). The experimental species was brook trout (Salvelinus fontinalis L.) with average weight of 156 ? 4,91 g. The test was carried out for 135 days and there were 2 diets. Diet A (rapeseed oil, RO) or B (fish oil, F...

  19. Experimental and natural host specificity of Loma salmonae (Microsporidia).

    Science.gov (United States)

    Shaw, R W; Kent, M L; Brown, A M; Whipps, C M; Adamson, M L

    2000-03-14

    The microsporidian Loma salmonae (Putz, Hoffman & Dunbar, 1965) Morrison & Sprague, 1981 has caused significant gill disease in Pacific salmon Oncorhynchus spp. Host specificity of the parasite was examined experimentally by per os challenge of selected salmonids and non-salmonids with infective chinook salmon O. tshawytscha gill material. Pink Oncorhynchus gorbuscha and chum salmon O. keta, brown Salmo trutta and brook trout Salvelinus fontinalis, and chinook salmon (controls) were positive, whereas Atlantic salmon Salmo salar and Arctic char Salvelinus alpinus were negative. In addition, no non-salmonids were susceptible to experimental exposure. Wild Pacific salmon species in British Columbia, Canada, were examined for L. salmonae during their freshwater life history stages (smolts, prespawning, spawning). All stages were infected, although infections in smolts were only detectable using a L. salmonae-specific PCR test. Many previous Loma spp. described from Oncorhychus spp. are likely L. salmonae based on host, parasite morphology, and site of infection. PMID:10782347

  20. Functional morphology and biomechanics of the tongue-bite apparatus in salmonid and osteoglossomorph fishes.

    Science.gov (United States)

    Camp, Ariel L; Konow, Nicolai; Sanford, Christopher P J

    2009-05-01

    The tongue-bite apparatus and its associated musculoskeletal elements of the pectoral girdle and neurocranium form the structural basis of raking, a unique prey-processing behaviour in salmonid and osteoglossomorph fishes. Using a quantitative approach, the functional osteology and myology of this system were compared between representatives of each lineage, i.e. the salmonid Salvelinus fontinalis (N = 10) and the osteoglossomorph Chitala ornata (N = 8). Divergence was found in the morphology of the novel cleithrobranchial ligament, which potentially relates to kinematic differences between the raking lineage representatives. Salvelinus had greater anatomical cross-sectional areas of the epaxial, hypaxial and protractor hyoideus muscles, whereas Chitala had greater sternohyoideus and adductor mandibulae mass. Two osteology-based biomechanical models (a third-order lever for neurocranial elevation and a modified four-bar linkage for hyoid retraction) showed divergent force/velocity priorities in the study taxa. Salvelinus maximizes both force (via powerful cranial muscles) and velocity (through mechanical amplification) during raking. In contrast, Chitala has relatively low muscle force but more efficient force transmission through both mechanisms compared with Salvelinus. It remains unclear if and how behavioural modulation and specializations in the post-cranial anatomy may affect the force/velocity trade-offs in Chitala. Further studies of tongue-bite apparatus morphology and biomechanics in a broader species range may help to clarify the role that osteology and myology play in the evolution of behavioural diversity. PMID:19438765

  1. Cercariae of the lakes Maarsseveen (Netherlands) infecting Bithynia spp. (Gastropoda: Prosobranchia) and Physa fontinalis (Gastropoda: Pulmonata)

    OpenAIRE

    Keulen, Stef M.A.

    1981-01-01

    In 1978 cercariae have been collected from four species of freshwater snails in two lakes near Utrecht (Netherlands). Eleven species are recorded, of which six are described in detail. Five of these are new: Cercaria gutta n. sp. (Psilostomidae), C. cana n. sp. (Notocotilydae), C. quadrata n. sp. (Pleurogenetinae), C. abdita n. sp. and C. dyjannae n. sp. (both probably belonging to the Plagiorchiida, because they show characters of the group of Xiphidocercariae). Of C. dyjannae only the metac...

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

    Directory of Open Access Journals (Sweden)

    DELACOSTE M.

    1997-01-01

    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.

  3. Geosmin causes off-flavour in arctic charr in recirculating aquaculture systems

    Science.gov (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 ...

  4. 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;

    2012-01-01

    Trophic niche divergence is considered to be a major process by which species coexistence is facilitated. When studying niche segregation in lake ecosystems, we tend to view the niche on a one-dimensional pelagic-littoral axis. In reality, however, the niche use may be more complex and individual...... 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...... fidelity to a niche may be variable both between and within populations. In order to study this complexity, relative simple systems with few species are needed. In this paper, we study how competitor presence affects the resource use of brown trout (Salmo trutta) in 11 species-poor Faroese lakes by...

  5. Snake River sockeye salmon habitat and limnological research: Annual report 1997

    International Nuclear Information System (INIS)

    Since the late 1980's, Snake River sockeye Oncorhynchus nerka adults have only returned to Redfish Lake, one of five lakes in the Sawtooth Basin which historically reared sockeye. 1997 project objectives included (1) characterization of the limnology of Sawtooth Valley lakes; (2) fertilization of Redfish, Pettit, and Alturas lakes; (3) O.nerka lake population surveys; (4) estimation of kokanee escapement and fry production in Alturas Lake Creek, Stanley Lake Creek, and Fishhook Creek; (5) reduce the number of spawning kokanee in Fishook Creek; (6) evaluate hatchery rainbow trout overwinter survival and potential competition and predation interactions with O.nerka in Pettit Lake; (7) assess predation from bull trout Salvelinus malma, brook trout S.fontinalis, and northern squawfish Ptychocheilus oregonsis on lentic O.nerka; (8) establish screw tap and weir sites to monitor smolt emigration

  6. Exposure-related effects of Pseudomonas fluorescens, strain CL145A, on coldwater, coolwater, and warmwater fish

    Science.gov (United States)

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

    2015-01-01

    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]).

  7. Do native brown trout and non-native brook trout interact reproductively?

    Science.gov (United States)

    Cucherousset, J.; Aymes, J. C.; Poulet, N.; Santoul, F.; Céréghino, R.

    2008-07-01

    Reproductive interactions between native and non-native species of fish have received little attention compared to other types of interactions such as predation or competition for food and habitat. We studied the reproductive interactions between non-native brook trout ( Salvelinus fontinalis) and native brown trout ( Salmo trutta) in a Pyrenees Mountain stream (SW France). We found evidence of significant interspecific interactions owing to consistent spatial and temporal overlap in redd localizations and spawning periods. We observed mixed spawning groups composed of the two species, interspecific subordinate males, and presence of natural hybrids (tiger trout). These reproductive interactions could be detrimental to the reproduction success of both species. Our study shows that non-native species might have detrimental effects on native species via subtle hybridization behavior.

  8. Synchronizace ovulace jikernaček sivena amerického a pstruha duhového

    OpenAIRE

    JANKOVÝCH, Antonín

    2012-01-01

    The effect of GnRH analogue on synchronizing ovulation in the female brook charr and rainbow trout was assessed in 3 experiments (2010- brook charr, 2011-brook charr+rainbow trout). Prior to the onset of the spawning season females of brook charr and rainbow trout were hormonaly stimulated.

  9. Component population study of Acanthocephalus tumescens (Acanthocephala) in fishes from Lake Moreno, Argentina.

    Science.gov (United States)

    Rauque, Carlos A; Viozzi, Gustavo P; Semenas, Liliana G

    2003-03-01

    Seasonal samples of all fish species from Lake Moreno were taken in order to determine the presence of paratenia, to evaluate the status of the hosts and to characterise the transmission of Acanthocephalus tumescens (von Linstow, 1896) at the component population level. Prevalence, mean abundance, mean intensity, numbers of gravid females, relative abundance of the different fish species, relative output of eggs and relative flow rates for each host species were computed. Acanthocephalus tumescens showed low host specificity, successfully parasitizing six out of eight fish species present in the lake. No paratenic infection was registered. If prevalence, mean abundance, and number of gravid females are considered, host species can be placed in a continuum from the most to least suitable as follows: Galaxias platei Steindachner, Diplomystes viedmensis (Mac Donagh), Oncorhynchus mykiss (Walbaum), Salvelinus fontinalis (Mitchill), Percichthys trucha (Cuvier et Valenciennes) and Galaxias maculatus (Jenyns). However, when parasite flow rates and egg output were calculated, including relative abundance of each fish species, the continuum was rearranged as follows: P. trucha, O. mykiss, G. platei / G. maculatus, S. fontinalis and D. viedmensis. The first four species would be the main contributors to the population of A. tumescens in this lake, P. trucha being the major one. Different regulatory and non-regulatory mechanisms are suggested. PMID:12735727

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-06-01

    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.

  11. Role of climate and invasive species in structuring trout distributions in the interior Columbia River Basin, USA

    Science.gov (United States)

    Wenger, Seth J.; Isaak, Daniel J.; Dunham, Jason B.; Fausch, Kurt D.; Luce, Charles H.; Neville, Helen M.; Rieman, Bruce E.; Young, Michael K.; Nagel, David E.; Horan, Dona L.; Chandler, Gwynne L.

    2011-01-01

    Recent and projected climate warming trends have prompted interest in impacts on coldwater fishes. We examined the role of climate (temperature and flow regime) relative to geomorphology and land use in determining the observed distributions of three trout species in the interior Columbia River Basin, USA. We considered two native species, cutthroat trout (Oncorhynchus clarkii) and bull trout (Salvelinus confluentus), as well as nonnative brook trout (Salvelinus fontinalis). We also examined the response of the native species to the presence of brook trout. Analyses were conducted using multilevel logistic regression applied to a geographically broad database of 4165 fish surveys. The results indicated that bull trout distributions were strongly related to climatic factors, and more weakly related to the presence of brook trout and geomorphic variables. Cutthroat trout distributions were weakly related to climate but strongly related to the presence of brook trout. Brook trout distributions were related to both climate and geomorphic variables, including proximity to unconfined valley bottoms. We conclude that brook trout and bull trout are likely to be adversely affected by climate warming, whereas cutthroat trout may be less sensitive. The results illustrate the importance of considering species interactions and flow regime alongside temperature in understanding climate effects on fish.

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

    Directory of Open Access Journals (Sweden)

    Torvald Blikra Egeland

    2015-07-01

    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.

  13. Plastic resource polymorphism: effects of resource availability on Arctic char ( Salvelinus alpinus ) morphology

    NARCIS (Netherlands)

    J. Andersson; P. Bystrom; L. Persson; A.M. de Roos

    2005-01-01

    6. Abstract (optional): Resource polymorphism has been suggested to be a platform for speciation. In some cases resource polymorphism depends on phenotypic plasticity but in other cases on genetic differences between morphotypes, which in turn has been suggested to be the ongoing development of a sp

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

    Science.gov (United States)

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

    2014-01-01

    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.

  15. Teleost reproduction: Aspects of Arctic char (Salvelinus alpinus) oocyte growth and maturation.

    OpenAIRE

    Berg, Håkan

    2003-01-01

    In all vertebrate species, reproduction is a hormonally controlled process, important for growth and maturation of gonads and germ cells. Production of functional germ cells is of outmost importance to secure the survival of a species. Fish comprises 50% of the known vertebrates and are found in aquatic habitats all over the world. Even though fish have evolved a wide variety of morphological and physiological characteristics, due to large differences in the living environment, the growth an ...

  16. Mercury in the biotic compartments of Northwest Patagonia lakes, Argentina.

    Science.gov (United States)

    Rizzo, A; Arcagni, M; Arribére, M A; Bubach, D; Guevara, S Ribeiro

    2011-06-01

    We report on total mercury (THg) concentrations in the principal components of food webs of selected Northern Patagonia Andean Range ultraoligotrophic lakes, Argentina. The THg contents were determined using Instrumental Neutron Activation Analysis in muscle and liver of four fish species occupying the higher trophic positions (the introduced Salmo trutta, Oncorhynchus mykiss and Salvelinus fontinalis, and the native Percichthys trucha) accounted for eight lakes belonging to Nahuel Huapi and Los Alerces National Parks. We studied the food web components of both the West and East branches of Lake Moreno, including benthic primary producers such as biofilm, mosses, and macrophytes, three plankton fractions, fish, riparian tree leaves, and benthic invertebrates, namely decapods, molluscs, insect larvae, leeches, oligochaetes, and amphipods. Mercury concentrations in fish muscle varied in a wide range, from less than 0.05 to 4 μg g(-1) dry weight (DW), without a distribution pattern among species but showing higher values for P. trucha and S. fontinalis, particularly in Lake Moreno. The THg contents of the food web components of Lake Moreno varied within 4 orders of magnitude, with the lower values ranging from 0.01 to 0.5 μg g(-1) DW in tree leaves, some macrophytes, juvenile salmonids or benthic macroinvertebrates, and reaching concentrations over 200 μg g(-1) DW in the plankton. Juvenile Galaxias maculatus caught in the pelagic area presented the highest THg contents of all fish sampled, reaching 10 μg g(-1) DW, contents that could be associated with the high THg concentrations in plankton since it is their main food source. Although Lake Moreno is a system without local point sources of contamination, situated in a protected area, some benthic organisms presented high THg contents when compared with those from polluted ecosystems. PMID:21421254

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

    Science.gov (United States)

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

    2012-01-01

    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.

  18. Congruence between muscle activity and kinematics in a convergently derived prey-processing behavior.

    Science.gov (United States)

    Konow, Nicolai; Camp, Ariel L; Sanford, Christopher P J

    2008-08-01

    Quantification of anatomical and physiological characteristics of the function of a musculoskeletal system may yield a detailed understanding of how the organizational levels of morphology, biomechanics, kinematics, and muscle activity patterns (MAPs) influence behavioral diversity. Using separate analyses of these organizational levels in representative study taxa, we sought patterns of congruence in how organizational levels drive behavioral modulation in a novel raking prey-processing behavior found in teleosts belonging to two evolutionarily distinct lineages. Biomechanically divergent prey (elusive, robust goldfish and sedentary, malleable earthworms) were fed to knifefish, Chitala ornata (Osteoglossomorpha) and brook trout, Salvelinus fontinalis (Salmoniformes). Electromyography recorded MAPs from the hyoid protractor, jaw adductor, sternohyoideus, epaxialis, and hypaxialis musculature, while sonomicrometry sampled deep basihyal kinesis and contractile length dynamics in the basihyal protractor and retractor muscles. Syntheses of our results with recent analyses of cranial morphology and raking kinematics showed that raking in Salvelinus relies on an elongated cranial out lever, extensive cranial elevation and a curved cleithrobranchial ligament (CBL), and that both raking MAPs and kinematics remain entirely unmodulated-a highly unusual trait, particularly among feeding generalists. Chitala had a shorter CBL and a raking power stroke involving increased retraction of the elongated pectoral girdle during raking on goldfish. The raking MAP was also modulated in Chitala, involving an extensive overlap between muscle activity of the preparatory and power stroke phases, driven by shifts in hypaxial timing and recruitment of the hyoid protractor muscle. Sonomicrometry revealed that the protractor hyoideus muscle stored energy from retraction of the pectoral girdle for ca. 5-20 ms after onset of the power stroke and then hyper-extended. This mechanism of elastic

  19. Adaptive Management of Bull Trout Populations in the Lemhi Basin

    Science.gov (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.

    2011-01-01

    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.

  20. Flavobacterium psychrophilum Infections in Salmonid Broodstock and Hatchery-Propagated Stocks of the Great Lakes Basin.

    Science.gov (United States)

    Van Vliet, Danielle; Loch, Thomas P; Faisal, Mohamed

    2015-12-01

    Bacterial coldwater disease (BCWD), caused by Flavobacterium psychrophilum, threatens wild and propagated salmonids worldwide and leads to substantial economic losses. In addition to being horizontally transmitted, F. psychrophilum can be passed from infected parents to their progeny, furthering the negative impacts of this pathogen. In Michigan, both feral and captive salmonid broodstocks are the gamete sources used in fishery propagation efforts. A 5-year study was initiated to follow the prevalence of systemic F. psychrophilum infections in feral broodstocks of four species (steelhead Oncorhynchus mykiss [potadromous Rainbow Trout]; Coho Salmon O. kisutch; Chinook Salmon O. tshawytscha; and Atlantic Salmon Salmo salar) residing in three Great Lakes watersheds. Additionally, captive broodstocks of four species (Rainbow Trout, Brown Trout Salmo trutta, Lake Trout Salvelinus namaycush, and Brook Trout Salvelinus fontinalis) maintained at two facilities were assessed for the presence of F. psychrophilum. The resultant offspring from each broodstock population were sampled for F. psychrophilum infections multiple times throughout hatchery residency. Using selective flavobacterial culture and PCR confirmation, F. psychrophilum was detected in all broodstocks except the captive Lake Trout and Brook Trout. Logistic regression analysis demonstrated that among the infected feral broodstocks, Chinook Salmon from the Lake Michigan watershed had the highest prevalence of systemic F. psychrophilum infection (mean = 63.2%). Among the captive broodstocks, the Gilchrist Creek strain of Brown Trout had the highest infection prevalence (mean = 5%). Collectively, the captive broodstocks were found to have significantly lower infection prevalence than the feral broodstocks. Despite the high prevalence of systemic F. psychrophilum infections in many broodstock populations, the bacterium was rarely detected in their progeny during hatchery rearing. However, heavy losses associated

  1. Fontinalis antipyretica as a bioindicator of environmental conditions in freshwater ecosystem from Sava River watershed and Cerknişko Lake, Slovenia

    Science.gov (United States)

    Kanduč, Tjaša; Mechora, Špela; Stibilj, Vekoslava

    2014-05-01

    Polluted waters recharging from agriculture water systems into watersheds have influence on water quality and living habitat. Stable isotopes of carbon and nitrogen in combination with other minor and trace elements are often used to trace biogeochemical processes and contamination of water systems. The aim of the study was to assess state of environment with minor and trace elements and stable isotopes of C and N in selected Slovenian streams. Ten locations in Notranjska region, Slovenia, with different land use in the catchment (town, village, agricultural areas, farms, dairy farms), including reference point considered as non-polluted site, were sampled. Samples of water and aquatic moss F. antipyretica in Slovenian fresh waters were taken in all four seasons during years 2010 and 2012, but for stable isotope analyses of C and N only in three seasons during years 2010 and 2011. The water chemistry of investigated locations is dominated by hydrogen carbonate - calcium - magnesium, concentrations of nitrate seasonally range from 2.07 mg/l to 6.4 mg/l and at reference site does not exceed 1.3 mg/l. Total alkalinity of water at investigated locations ranges from 2.9 to 6.02 mM. The pH of investigated water range from 7.2 to 8.5, waters are saturated with oxygen (up to 134%) and conductivity ranges from 295 to 525 mikroS/cm, while at reference site conductivity is up to 180 mikroS/cm. The content of minor and trace elements in F. antipyretica ranged for Ni 4-38 mikrog/g, Zn 17-105 mikrog/g, Pb 2-28 mikrog/g, Cd 220-1953 ng/g, Cu 4-27 mikrog/g, Cr 4-49 mikrog/g, As 1-6 mikrog/g and Se 0.33-3.24 mikrog/g. The most polluted watershed was Pšata stream (agricultural areas, cattle farm) with highest values for Ni, Cr, Pb, Zn and As. The highest content of Se, was found in village (dairy farms) in Žerovniščica stream. The highest values were measured in February and October. Isotopic composition of dissolved inorganic carbon seasonally range from -13.3 to -8.1‰, and indicate waters dominated by degradation of organic matter and dissolution of carbonates. At the reference point average measured isotopic composition of dissolved inorganic carbon value is -2.7‰ which confirmed that this is a non-polluted site. Isotopic composition of carbon of F. antipyretica seasonally ranges from -45 to -32.9‰ and isotopic composition of nitrogen from -0.2‰ to 6.5‰, respectively. In comparison to C3 terrestrial plants F. antipyretica has more negative isotopic composition of carbon value, which is probably related with the difference in CO2 plant fixation and depends on isotopic composition of dissolved inorganic carbon in water, which is primarily controlled by geological composition and soil thickness in the watershed. Higher isotopic composition of nitrogen value found in F. antipyretica is related to agricultural activity in watershed, while at the reference site measured isotopic composition of nitrogen value is -4.1 ‰. From our study it is evident that isotopic composition of carbon and nitrogen is useful tracer of natural and anthropogenic inputs from terrestrial (fertilizing, sewage sludge) to water system.

  2. Heritability of morphology in brook trout with variable life histories.

    Directory of Open Access Journals (Sweden)

    Anna Varian

    Full Text Available Distinct morphological variation is often associated with variation in life histories within and among populations of both plants and animals. In this study, we examined the heritability of morphology in three hatchery strains of brook trout (Salvelinus fontinalis, which were historically or are currently used for stocking and supplementation of both migratory and resident ecotypes in the upper Great Lakes region. In a common garden experiment, significant variation in body morphology was observed within and across populations sampled at three time periods. The most notable differences among strains were differences in dorso-ventral body depth and the shape of the caudal peduncle, with some differences in the anterior-posterior placement of the dorsal and ventral fins. Variation with and among 70 half-sib families indicates that heritabilities of morphology and body size were significant at most developmental time points both within and across strains. Heritabilities for morphological characters within strains ranged from 0 to 0.95 across time points. Significant within-strain heritabilities for length ranged from 0 to 0.93 across time points and for weight ranged from 0 to 0.88. Significant additive genetic variation exists within and across hatchery brook trout strains for morphology and size, indicating that these traits are capable of responding to natural or artificial selection.

  3. Recovery of a fish pathogenic bacterium, Aeromonas salmonicida, from ebonyshell mussels Fusconaia ebena using nondestructive sample collection procedures

    Science.gov (United States)

    Starliper, C.E.

    2008-01-01

    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.

  4. Polyphasic characterization of Aeromonas salmonicida isolates recovered from salmonid and non-salmonid fish

    Science.gov (United States)

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

    2013-01-01

    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.

  5. Genetic identity of brook trout in Lake Superior south shore streams: Potential for genetic monitoring of stocking and rehabilitation efforts

    Science.gov (United States)

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

    2008-01-01

    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.

  6. Maintenance of phenotypic variation: Repeatability, heritability and size-dependent processes in a wild brook trout population

    Science.gov (United States)

    Letcher, B.H.; Coombs, J.A.; Nislow, K.H.

    2011-01-01

    Phenotypic variation in body size can result from within-cohort variation in birth dates, among-individual growth variation and size-selective processes. We explore the relative effects of these processes on the maintenance of wide observed body size variation in stream-dwelling brook trout (Salvelinus fontinalis). Based on the analyses of multiple recaptures of individual fish, it appears that size distributions are largely determined by the maintenance of early size variation. We found no evidence for size-dependent compensatory growth (which would reduce size variation) and found no indication that size-dependent survival substantially influenced body size distributions. Depensatory growth (faster growth by larger individuals) reinforced early size variation, but was relatively strong only during the first sampling interval (age-0, fall). Maternal decisions on the timing and location of spawning could have a major influence on early, and as our results suggest, later (>age-0) size distributions. If this is the case, our estimates of heritability of body size (body length=0.25) will be dominated by processes that generate and maintain early size differences. As a result, evolutionary responses to environmental change that are mediated by body size may be largely expressed via changes in the timing and location of reproduction. Published 2011. This article is a US Government work and is in the public domain in the USA.

  7. Water striders (family Gerridae): mercury sentinels in small freshwater ecosystems

    International Nuclear Information System (INIS)

    To circumvent some of the previous limitations associated with contaminant-monitoring programs, we tested the suitability of the water strider (Hemiptera: Gerridae) as a mercury sentinel by comparing total mercury concentrations in water striders and brook trout (Salvelinus fontinalis) from a variety of stream sites in New Brunswick, Canada. There was a strong association between the two variables across sites (r2 = 0.81, P < 0.001) in systems where both atmospheric deposition and a point source (an abandoned gold mine) were likely contributing to ambient mercury levels. In a small stream draining the gold mine tailings pile, water striders had mercury concentrations an order of magnitude higher than those from reference locations. Temporal variation at three southern New Brunswick stream sites was non-significant. These results suggest that water strider mercury levels accurately quantify food chain entry of the element. The use of sentinel species holds great potential for expanding contaminant-monitoring programs. - Water striders accurately reflect the entry of mercury in food chains of small freshwater systems

  8. Conservation genetics of Lake Superior brook trout: Issues, questions, and directions

    Science.gov (United States)

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

    2008-01-01

    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.

  9. Growth rate differences between resident native brook trout and non-native brown trout

    Science.gov (United States)

    Carlson, S.M.; Hendry, A.P.; Letcher, B.H.

    2007-01-01

    Between species and across season variation in growth was examined by tagging and recapturing individual brook trout Salvelinus fontinalis and brown trout Salmo trutta across seasons in a small stream (West Brook, Massachusetts, U.S.A.). Detailed information on body size and growth are presented to (1) test whether the two species differed in growth within seasons and (2) characterize the seasonal growth patterns for two age classes of each species. Growth differed between species in nearly half of the season- and age-specific comparisons. When growth differed, non-native brown trout grew faster than native brook trout in all but one comparison. Moreover, species differences were most pronounced when overall growth was high during the spring and early summer. These growth differences resulted in size asymmetries that were sustained over the duration of the study. A literature survey also indicated that non-native salmonids typically grow faster than native salmonids when the two occur in sympatry. Taken together, these results suggest that differences in growth are not uncommon for coexisting native and non-native salmonids. ?? 2007 The Authors.

  10. Thermal onset of cellular and endocrine stress responses correspond to ecological limits in brook trout, an iconic cold-water fish

    Science.gov (United States)

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

    2015-01-01

    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.

  11. A comparative study on water column and bottom feeding habit of tank reared brook trout

    International Nuclear Information System (INIS)

    Feed consumption growth rate and feed conversion were compared for brook trout (Salvelinus fontinalis) feeding in the water column or at the tank bottom. The trial that lasted 120 days was conducted in four 300 L fibreglass tanks with two replicates of fish (mean weight of 45.9 g) in each feeding treatment. Fish fed in the water column exhibited a mean (SD) specific growth rate(SGR) of 0.93 and reached a final mean weight of 138.9 (28.9) g whereas bottom fed fish had a mean SGR of 0.91 and 135.7 (39.2) g body weight. Overall feed conversion ratios (FCR) and condition factors (CF) were assessed as 1.73, 1.22 for the water column and 1.71, 1.25 bottom fed fish. None of these variables showed statistically significant difference between the treatments. thus, it seems that brook trout may feed both in water column and at bottom in tank culture conditions and this habit could be utilised for reducing feed waste in intensive commercial trout culture

  12. Brook trout passage performance through culverts

    Science.gov (United States)

    Goerig, Elsa; Castro-Santos, Theodore R.; Bergeron, Normand

    2016-01-01

    Culverts can restrict access to habitat for stream-dwelling fishes. We used passive integrated transponder telemetry to quantify passage performance of >1000 wild brook trout (Salvelinus fontinalis) attempting to pass 13 culverts in Quebec under a range of hydraulic and environmental conditions. Several variables influenced passage success, including complex interactions between physiology and behavior, hydraulics, and structural characteristics. The probability of successful passage was greater through corrugated metal culverts than through smooth ones, particularly among smaller fish. Trout were also more likely to pass at warmer temperatures, but this effect diminished above 15 °C. Passage was impeded at higher flows, through culverts with steep slopes, and those with deep downstream pools. This study provides insight on factors influencing brook trout capacity to pass culverts as well as a model to estimate passage success under various conditions, with an improved resolution and accuracy over existing approaches. It also presents methods that could be used to investigate passage success of other species, with implications for connectivity of the riverscape.

  13. A real-time PCR method for the quantification of the two isoforms of metallothionein in Lake Trout (Salvelinus namaycush).

    Science.gov (United States)

    Werner, Julieta; Palace, Vince; Baron, Christopher; Shiu, Robert; Yarmill, Alison

    2008-01-01

    Metallothioneins (MTs) are low-molecular-weight proteins whose physiologic roles are the regulation of essential metals Cu and Zn, sequestration of heavy metals, and free radical scavenging. Induced production of MTs in a wide variety of organisms exposed to heavy metals has made them popular exposure indicators. While it has been postulated that the three different isoforms of MT play different physiologic roles, methods to discern induction separately have not been available. The development of real-time polymerase chain reaction (real-time PCR) primers and TaqMan probes to measure the two MT isoforms found in salmonid fish are described. Assuming a high degree of homology between the isoforms and within different groups of salmonids, the sequences for MT-I and MT-II from rainbow trout were used to develop primers and probes for lake trout using the Primer3 program. Two sections of each isoform that varied by only a few nucleotides were targeted. SYBR Green validated the primer specificity, and melt curve analysis further ensured that only one product was amplified. Analysis of archived samples from fish captured in unmanipulated reference lakes or from lakes experimentally treated with cadmium or ethynylestradiol (EE2) afforded an examination of seasonal and contaminant influences on MT-I and MT-II mRNA expression. PMID:17687585

  14. 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.;

    2015-01-01

    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...

  15. Evolution and origin of sympatric shallow-water morphotypes of Lake Trout, Salvelinus namaycush, in Canada's Great Bear Lake

    OpenAIRE

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

    2014-01-01

    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 i...

  16. 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: kiddk@unbsj.ca [Canadian Rivers Institute and Biology Department, University of New Brunswick, Saint John, NB, Canada E2L 4L5 (Canada); Muir, Derek C.G., E-mail: derek.muir@ec.gc.ca [Aquatic Contaminants Research Division, Environment Canada, Burlington, ON, Canada L7R 4A6 (Canada); Evans, Marlene S., E-mail: marlene.evans@ec.gc.ca [Aquatic Contaminants Research Division, Environment Canada, Saskatoon, SK, Canada S7N 3H5 (Canada); Wang, Xioawa, E-mail: xiaowa.wang@ec.gc.ca [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: heidikswanson@yahoo.ca [Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9 (Canada); Johnston, Tom, E-mail: tjohnston@laurentian.ca [Cooperative Freshwater Ecology Unit, Ontario Ministry of Natural Resources, and Biology Department, Laurentian University, Sudbury, ON, Canada P3E 2C6 (Canada); Guildford, Stephanie, E-mail: sguildfo@d.umn.edu [Department of Biology and Large Lakes Observatory, University of Minnesota Duluth, 2205 5th St., Duluth, MN, 55812 (United States)

    2012-11-01

    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.

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

    International Nuclear Information System (INIS)

    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 (δ15N), 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 δ15N 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 (δ15N; δ13C 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: ► Mercury biomagnifies through aquatic food webs to toxic levels in top predator fishes. ► Among-system differences in mercury transfer through food webs occur but have not been explained. ► Diverse lakes supporting lake trout were compared to understand the ecosystem processes that affect mercury biomagnification. ► Higher biomagnification of mercury was found in larger, higher nutrient lakes. ► Results show that the food web processing of mercury is related to ecosystem properties.

  18. Community structure influences species' abundance along environmental gradients.

    Science.gov (United States)

    Eloranta, Antti P; Helland, Ingeborg P; Sandlund, Odd T; Hesthagen, Trygve; Ugedal, Ola; Finstad, Anders G

    2016-01-01

    Species' response to abiotic environmental variation can be influenced by local community structure and interspecific interactions, particularly in restricted habitats such as islands and lakes. In temperate lakes, future increase in water temperature and run-off of terrestrial (allochthonous) dissolved organic carbon (DOC) are predicted to alter community composition and the overall ecosystem productivity. However, little is known about how the present community structure and abiotic environmental variation interact to affect the abundance of native fish populations. We used a space-for-time approach to study how local community structure interact with lake morphometric and climatic characteristics (i.e. temperature and catchment productivity) to affect brown trout (Salmo trutta L.) yield in 283 Norwegian lakes located in different biogeographical regions. Brown trout yield (based on data from standardized survey gill net fishing; g 100 m(-2) gill net night(-1)) was generally lower in lakes where other fish species were present than in lakes with brown trout only. The yield showed an overall negative relationship with increasing temperature and a positive relationship with lake shoreline complexity. Brown trout yield was also negatively correlated with DOC load (measured using Normalized Difference Vegetation Index as a proxy) and lake size and depth (measured using terrain slope as a proxy), but only in lakes where other fish species were present. The observed negative response of brown trout yield to increasing DOC load and proportion of the pelagic open-water area is likely due to restricted (littoral) niche availability and competitive dominance of more pelagic fishes such as Arctic charr (Salvelinus alpinus (L.)). Our study highlights that, through competitive interactions, the local community structure can influence the response of a species' abundance to variation in abiotic conditions. Changes in biomass and niche use of top predators (such as the brown

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-11-18

    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

  20. Virulence of Renibacterium salmoninarum to salmonids

    Science.gov (United States)

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

    1997-01-01

    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

  1. Exploring crowded trophic niche space in a novel reservoir fish assemblage: how many predators is too many?

    Science.gov (United States)

    Winters, Lisa K.; Budy, Phaedra

    2015-01-01

    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

  2. Stochastic life history modeling for managing regional-scale freshwater fisheries: an experimental study of brook trout.

    Science.gov (United States)

    Adams, Blair K; Cote, David; Fleming, Ian A

    2016-04-01

    Environmental heterogeneity can combine with evolutionary responses to create very dynamic and often locally independent populations across a landscape. Such complexity creates difficulties for managers trying to conserve populations across large areas. This study develops, applies, and tests the use of stochastic life history modeling and Monte Carlo simulation to assess management scenarios related to the realities of regional fisheries management and conservation. We apply this approach to the management of recreational brook trout (Salvelinus fontinalis) fishing; an activity that can severely impact species balance, abundance, and the size structure of fish communities. Specifically, the model incorporates population-specific life-history information (e.g., growth rate, reproductive effort, and survival) to allow forecasts of the impact of various management strategies and/or changes to environmental conditions on a population's ecological characteristics (e.g., size structure, abundance, and probability of persistence). Sampling was carried out in 16 water bodies spread across four sites in Atlantic Canada. Each water body was sampled in 2005 and reassessed in 2008. This sampling had two primary objectives: (1) define a significant proportion of life-history variation of brook trout in Atlantic Canada, and (2) to test the precision and accuracy of model predictions of population responses to experimental exploitation and management changes. The model successfully predicted population responses to changes in adult survival in 12 of 13 populations having sufficient data for validation testing, while also proving to be a useful tool when engaging stakeholders regarding management options and their associated risk. We suggest that such models are cost-effective and have great potential for informing proactive management of jurisdictions with numerous and diverse populations. PMID:27411259

  3. Frequency and Severity of Trauma in Fishes Subjected to Multiple-pass Depletion Electrofishing

    Science.gov (United States)

    Panek, Frank; Densmore, Christine L.

    2013-01-01

    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.

  4. Effect of dominance status on sex hormone levels in laboratory and wild-spawning male trout.

    Science.gov (United States)

    Cardwell, J R; Sorensen, P W; Van der Kraak, G J; Liley, N R

    1996-03-01

    We investigated the relationship between male social status and hormone levels in salmonids spawning under laboratory and field conditions. In small groups of rainbow trout (Onchorhynchus mykiss) spawning in the laboratory, dominant males had higher plasma levels of testosterone (T) and 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one (17,20 beta-P) compared with subordinates. Steroid levels increased in subordinate males that became dominant after dominant males were experimentally removed; higher steroid levels in dominant males appears to be a result rather than a cause of their social status. In free-ranging brown trout (Salmo trutta) sampled in the field, we found higher levels of 11-ketotestosterone (11KT) but not T in dominant males. No significant differences in levels of either androgen were found between dominant and subordinate male brook trout (Salvelinus fontinalis) sampled at the same field location. Furthermore, in marked contrast with the laboratory fish, there were no significant differences in plasma 17,20 beta-P between dominant and subordinate males in either species of fish in the wild. The different findings in the laboratory and field may indicate species differences in behavioral endocrinology among brook, brown, and rainbow trout. Alternatively, the greater differential in hormonal profile of dominant and subordinate males in the laboratory may reflect the relative uniformity of the laboratory environment; this simple environment may allow competitively superior males to more completely dominate less competitive tank-mates and to exclude them from female sexual cues. In any case, these results suggest that the relationship between steroid hormones and spawning behavior in male salmonids is likely more complex than suggested by experiments conducted solely on laboratory-held rainbow trout. PMID:8729943

  5. Bull Trout life History, Genetics, Habitat Needs, and Limiting Factors in Central and Northeast Oregon, Annual Report 1995.

    Energy Technology Data Exchange (ETDEWEB)

    Hemmingsen, Alan R.; Buchanan, David V.; Howell, Philip J.

    1996-03-01

    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.

  6. 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.

    1999-02-01

    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

  7. Changes in seasonal climate outpace compensatory density-dependence in eastern brook trout

    Science.gov (United States)

    Bassar, Ronald D.; Letcher, Benjamin H.; Nislow, Keith H.; Whiteley, Andrew R.

    2016-01-01

    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.

  8. Evaluation of Infrasound and Strobe Lights for Eliciting Avoidance Behavior in Juvenile Salmon and Char

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Robert P.(BATTELLE (PACIFIC NW LAB)); Neitzel, Duane A.(BATTELLE (PACIFIC NW LAB)); Amidan, Brett G.(BATTELLE (PACIFIC NW LAB))

    2001-12-01

    Laboratory tests were conducted using juvenile chinook salmon Oncorhynchus tshawytscha, brook trout Salvelinus fontinalis, and rainbow trout O. mykiss to determine specific behavior responses to infrasound (< 20 Hz) and flashing strobe lights. The objective of these tests was to determine if juvenile salmonids could be deterred from entrainment at water diversion structures. 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 and by observing startle and habituation responses. Wild chinook salmon (40-45 mm TL) and hatchery reared chinook salmon (45-50 mm TL) exhibited avoidance responses when initially exposed to a 10-Hz volume displacement source of infrasound. Rainbow and eastern brook trout (25-100 mm TL) did not respond with avoidance or other behaviors to infrasound. Evidence of 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 consistent movement in wild chinook salmon (60% of the tests), hatchery reared chinook salmon (50%), and rainbow trout (80%). No measurable responses were observed for brook trout. Results indicate that consistent, repeatable responses can be elicited from some fish using high-intensity strobe lights under a controlled laboratory testing. The species 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.

  9. A comparative and experimental evaluation of performance of stocked diploid and triploid brook trout

    Science.gov (United States)

    Budy, Phaedra E.; Thiede, G.P.; Dean, A.; Olsen, D.; Rowley, G.

    2012-01-01

    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.

  10. An evaluation of the precision of fin ray, otolith, and scale age determinations for brook trout

    Science.gov (United States)

    Stolarski, J.T.; Hartman, K.J.

    2008-01-01

    The ages of brook trout Salvelinus fontinalis are typically estimated using scales despite a lack of research documenting the effectiveness of this technique. The use of scales is often preferred because it is nonlethal and is believed to require less effort than alternative methods. To evaluate the relative effectiveness of different age estimation methodologies for brook trout, we measured the precision and processing times of scale, sagittal otolith, and pectoral fin ray age estimation techniques. Three independent readers, age bias plots, coefficients of variation (CV = 100 x SD/mean), and percent agreement (PA) were used to measure within-reader, among-structure bias and within-structure, among-reader precision. Bias was generally minimal; however, the age estimates derived from scales tended to be lower than those derived from otoliths within older (age > 2) cohorts. Otolith, fin ray, and scale age estimates were within 1 year of each other for 95% of the comparisons. The measures of precision for scales (CV = 6.59; PA = 82.30) and otoliths (CV = 7.45; PA = 81.48) suggest higher agreement between these structures than with fin rays (CV = 11.30; PA = 65.84). The mean per-sample processing times were lower for scale (13.88 min) and otolith techniques (12.23 min) than for fin ray techniques (22.68 min). The comparable processing times of scales and otoliths contradict popular belief and are probably a result of the high proportion of regenerated scales within samples and the ability to infer age from whole (as opposed to sectioned) otoliths. This research suggests that while scales produce age estimates rivaling those of otoliths for younger (age > 3) cohorts, they may be biased within older cohorts and therefore should be used with caution. ?? Copyright by the American Fisheries Society 2008.

  11. Broad-scale patterns of Brook Trout responses to introduced Brown Trout in New York

    Science.gov (United States)

    McKenna Jr, James E.; Slattery, Michael T.; Kean M. Clifford

    2013-01-01

    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

  12. Brown trout and food web interactions in a Minnesota stream

    Science.gov (United States)

    Zimmerman, J.K.H.; Vondracek, B.

    2007-01-01

    1. We examined indirect, community-level interactions in a stream that contained non-native brown trout (Salmo trutta Linnaeus), native brook trout (Salvelinus fontinalis Mitchill) and native slimy sculpin (Cottus cognatus Richardson). Our objectives were to examine benthic invertebrate composition and prey selection of fishes (measured by total invertebrate dry mass, dry mass of individual invertebrate taxa and relative proportion of invertebrate taxa in the benthos and diet) among treatments (no fish, juvenile brook trout alone, juvenile brown trout alone, sculpin with brook trout and sculpin with brown trout). 2. We assigned treatments to 1 m2 enclosures/exclosures placed in riffles in Valley Creek, Minnesota, and conducted six experimental trials. We used three designs of fish densities (addition of trout to a constant number of sculpin with unequal numbers of trout and sculpin; addition of trout to a constant number of sculpin with equal numbers of trout and sculpin; and replacement of half the sculpin with an equal number of trout) to investigate the relative strength of interspecific versus intraspecific interactions. 3. Presence of fish (all three species, alone or in combined-species treatments) was not associated with changes in total dry mass of benthic invertebrates or shifts in relative abundance of benthic invertebrate taxa, regardless of fish density design. 4. Brook trout and sculpin diets did not change when each species was alone compared with treatments of both species together. Likewise, we did not find evidence for shifts in brown trout or sculpin diets when each species was alone or together. 5. We suggest that native brook trout and non-native brown trout fill similar niches in Valley Creek. We did not find evidence that either species had an effect on stream communities, potentially due to high invertebrate productivity in Valley Creek. ?? 2007 Blackwell Publishing Ltd.

  13. Landscape-scale evaluation of asymmetric interactions between Brown Trout and Brook Trout using two-species occupancy models

    Science.gov (United States)

    Wagner, Tyler; Jefferson T. Deweber; Jason Detar; John A. Sweka

    2013-01-01

    Predicting the distribution of native stream fishes is fundamental to the management and conservation of many species. Modeling species distributions often consists of quantifying relationships between species occurrence and abundance data at known locations with environmental data at those locations. However, it is well documented that native stream fish distributions can be altered as a result of asymmetric interactions between dominant exotic and subordinate native species. For example, the naturalized exotic Brown Trout Salmo trutta has been identified as a threat to native Brook Trout Salvelinus fontinalis in the eastern United States. To evaluate large-scale patterns of co-occurrence and to quantify the potential effects of Brown Trout presence on Brook Trout occupancy, we used data from 624 stream sites to fit two-species occupancy models. These models assumed that asymmetric interactions occurred between the two species. In addition, we examined natural and anthropogenic landscape characteristics we hypothesized would be important predictors of occurrence of both species. Estimated occupancy for Brook Trout, from a co-occurrence model with no landscape covariates, at sites with Brown Trout present was substantially lower than sites where Brown Trout were absent. We also observed opposing patterns for Brook and Brown Trout occurrence in relation to percentage forest, impervious surface, and agriculture within the network catchment. Our results are consistent with other studies and suggest that alterations to the landscape, and specifically the transition from a forested catchment to one that contains impervious surface or agriculture, reduces the occurrence probability of wild Brook Trout. Our results, however, also suggest that the presence of Brown Trout results in lower occurrence probability of Brook Trout over a range of anthropogenic landscape characteristics, compared with streams where Brown Trout were absent.

  14. 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.

  15. Bull trout life history, genetics, habitat needs, and limiting factors in central and northeast Oregon, Annual Report 1995

    International Nuclear Information System (INIS)

    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

  16. 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.

    2006-01-26

    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.

  17. 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)

    2004-03-01

    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.

  18. Seasonal Change in Trophic Niche of Adfluvial Arctic Grayling (Thymallus arcticus) and Coexisting Fishes in a High-Elevation Lake System

    Science.gov (United States)

    Cutting, Kyle A.; Cross, Wyatt F.; Anderson, Michelle L.; Reese, Elizabeth G.

    2016-01-01

    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. PMID:27205901

  19. Impacts of climatic variation on trout: A global synthesis and path forward

    Science.gov (United States)

    Kovach, Ryan; Muhlfeld, Clint C.; Al-Chokhachy, Robert K.; Dunham, Jason; Letcher, Benjamin; Kershner, Jeffrey L.

    2016-01-01

    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.

  20. 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: jenny.bytingsvik@akvaplan.niva.no [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)

    2015-07-15

    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.

  1. 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

    2010-07-01

    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

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

    Directory of Open Access Journals (Sweden)

    Brahmbhatt Sonal

    2008-11-01

    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

  3. Dicty_cDB: Contig-U15463-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available . 50 6e-15 5 ( AJ291570 ) Fontinalis antipyretica mitochondrial partial nad... 50 6e-15 5 ( EK279392 ) 10954...1570_1( AJ291570 |pid:none) Fontinalis antipyretica mitochondr... 265 2e-69 AJ291563_1( AJ291563 |pid:none)

  4. Biological Agents Influencing Physical Process in a Stream: A Case Study in Response to Human-Induced Alteration

    Science.gov (United States)

    Sondossi, H. A.; Bienz, C.

    2013-12-01

    ample depth variability. Water quality has improved to the point that it supports a healthy and expanding population of redband trout alongside introduced eastern brook trout (Salvelinus fontinalis). There have been no sightings of Oregon spotted frog yet, but the habitat is deemed suitable.

  5. Cellular and molecular evidence for a role of tumor necrosis factor alpha in the ovulatory mechanism of trout

    Directory of Open Access Journals (Sweden)

    Bobe Julien

    2010-04-01

    Full Text Available Abstract Background The relevance of immune-endocrine interactions to the regulation of ovarian function in teleosts is virtually unexplored. As part of the innate immune response during infection, a number of cytokines such as tumor necrosis factor alpha (TNF alpha and other immune factors, are produced and act on the reproductive system. However, TNF alpha is also an important physiological player in the ovulatory process in mammals. In the present study, we have examined for the first time the effects of TNF alpha in vitro in preovulatory ovarian follicles of a teleost fish, the brown trout (Salmo trutta. Methods To determine the in vivo regulation of TNF alpha expression in the ovary, preovulatory brook trout (Salvelinus fontinalis were injected intraperitoneally with either saline or bacterial lipopolysaccharide (LPS. In control and recombinant trout TNF alpha (rtTNF alpha-treated brown trout granulosa cells, we examined the percentage of apoptosis by flow cytometry analysis and cell viability by propidium iodide (PI staining. Furthermore, we determined the in vitro effects of rtTNF alpha on follicle contraction and testosterone production in preovulatory brown trout ovarian follicles. In addition, we analyzed the gene expression profiles of control and rtTNF alpha-treated ovarian tissue by microarray and real-time PCR (qPCR analyses. Results LPS administration in vivo causes a significant induction of the ovarian expression of TNF alpha. Treatment with rtTNF alpha induces granulosa cell apoptosis, decreases granulosa cell viability and stimulates the expression of genes known to be involved in the normal ovulatory process in trout. In addition, rtTNF alpha causes a significant increase in follicle contraction and testosterone production. Also, using a salmonid-specific microarray platform (SFA2.0 immunochip we observed that rtTNF alpha induces the expression of genes known to be involved in inflammation, proteolysis and tissue remodeling

  6. A regional neural network model for predicting mean daily river water temperature

    Science.gov (United States)

    Wagner, Tyler; DeWeber, Jefferson Tyrell

    2014-01-01

    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

  7. 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)

    2005-08-01

    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

  8. Bull trout distribution and abundance in the waters on and bordering the Warm Springs Indian Reservation: 2001 annual report

    International Nuclear Information System (INIS)

    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 fourth year (2001) of the multi-year study aimed at determining the life history, 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 were the lowest observed since surveys began in 1999. Relative densities of juvenile bull trout and brook trout increased in Shitike Cr. Juvenile bull trout vastly out numbered brook trout in Shitike Cr. 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 third year. Mean relative densities of juvenile bull trout within the index reaches was slightly higher than what was observed in the 2.4 km control reach. However, the mean relative density of brook trout in the 2.4 km control reach was slightly higher than what was observed in within the index reaches. Habitat use by both juvenile bull trout and brook trout was determined in the Warm Springs R. Juvenile bull trout and brook trout occupied pools more frequently than glides, riffles and rapids. However, pools accounted for only a small percentage

  9. 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)

    王伟伟

    2015-01-01

    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

  10. Phylogenetic Relationships among Members in Salmoninae and Genetic Variation amongDifferent Populationsof Rainbow Trout Farmedin China Basedon Cytb Sequence%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

    Institute of Scientific and Technical Information of China (English)

    王伟伟

    2015-01-01

    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

  11. 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)

    CLAUDIA A SILVA

    2008-03-01

    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

  12. 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

    2014-01-01

    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

  13. Acid rain publications by the U.S. Fish and Wildlife Service, 1979-1989

    Science.gov (United States)

    Villella, Rita F.

    1989-01-01

    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

  14. 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)

    2004-08-01

    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

  15. Consequent effects of the great cormorant (Phalacrocorax carbo sinensis) predation on parasite infection and body condition of common carp (Cyprinus carpio)

    Czech Academy of Sciences Publication Activity Database

    Ondračková, Markéta; Valová, Zdenka; Kortan, J.; Vojtek, L.; Adámek, Z.

    2012-01-01

    Roč. 110, č. 4 (2012), s. 1487-1493. ISSN 0932-0113 R&D Projects: GA MŠk LC522 Institutional support: RVO:68081766 Keywords : Ichthyophthirius multifiliis * Channel catfish * Crowding stress * Arctic charr * Fish * Susceptibility * Monogeneans Subject RIV: EG - Zoology Impact factor: 2.852, year: 2012

  16. HEAVY METAL ACCUMULATION IN SEDIMENT AND FRESHWATER FISH IN U.S. ARCTIC LAKES

    Science.gov (United States)

    Metal concentrations in sediment and two species of freshwater fish (lake trout [Salvelinus namaycush], and grayling [Thymallus arcticus]} were examined in four Arctic lakes in Alaska. Concentrations of several metals were naturally high in the sediment relative to uncontaminated...

  17. 75 FR 38768 - Ashley National Forest, UT, High Uintas Wilderness-Colorado River Cutthroat Trout Habitat...

    Science.gov (United States)

    2010-07-06

    ... Forest Service Ashley National Forest, UT, High Uintas Wilderness--Colorado River Cutthroat Trout Habitat...) proposes to restore genetically pure Colorado River cutthroat trout (CRCT; Onchorhynchus clarki pleuriticus... District. Nonnative fish species to be removed are primarily brook trout (Salvelinus...

  18. The Gastropods of Lake Eğirdir

    OpenAIRE

    YILDIRIM, Mehmet Zeki

    2004-01-01

    The Gastropoda species and its distribution was investigated in Lake Eğirdir. It was determined that 5 species belonging to Gastropoda, order Prosobranchia (Theodoxus heldreichi, Valvata naticina, Graecoanatolica lacustristurca, Falsipyrgula pfeiferi and Bithynia pseudemmericia) and 7 species belonging to the order Pulmonata (Radix peregra, Stagnicola palustris, Physa fontinalis, Physa acuta, Planorbis planorbis, Planorbis carinatus and Gyraulus albus) were present. Gastropoda species from 9 ...

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

    OpenAIRE

    A. M. Snow; Abdel E. Ghaly

    2008-01-01

    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....

  20. Effects of lake warming on behavioural thermoregulatory tactics in a cold-water stenothermic fish.

    Directory of Open Access Journals (Sweden)

    Katerine Goyer

    Full Text Available Despite some evidence of within-population phenotypic variation in fish thermal behaviour, the occurrence of alternative tactics of this behaviour is rarely explicitly considered when studying natural populations. Brook charr provide an example of within-population variability in behavioural thermoregulation as revealed by a recent study on a lacustrine population of this species. The objectives of the present study were (i to determine the influence of natural variability in the lake's thermal profiles on the expression of thermoregulatory tactics, and (ii to determine the vertical and horizontal movements of individuals at different periods of the day to better understand the spatio-temporal behaviour associated with each thermoregulatory tactic. During summer 2010, 30 adult brook charr were equipped with thermo-sensitive radio transmitters to monitor their selected temperatures and daily movements. These individuals exhibited the same four behavioural thermoregulatory tactics observed in 2003 and 2005, but the expression of two of these was weaker in 2010. This result was associated with lake warming, which constrained the expression of two thermoregulatory tactics: brook charr significantly decreased their selected temperatures and daily movements when the mean daily epilimnion temperature was above 22.4°C. This study shows for the first time that the expression of behavioural thermoregulatory tactics is related to the lake's thermal regime and that the tactics are plastic through time.

  1. Methods for processing aquatic mosses used as monitors of heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Wehr, J.D.; Empain, A.; Mouvet, C.; Say, P.J.; Whitton, B.A.

    1983-01-01

    An evaluation is reported of methods used to prepare mosses for analysis when required for monitoring metal pollution. Fontinalis antipyretica and Rhynchostegium riparioides taken from the River Hoegne, Belgium, were used for the study. The stages in preparation studied critically were the storage of the moss after it had been collected from the river, washing, choice of which particular fraction to use and the conditions for final drying prior to digestion. For any one particular treatment, the concentrations of metals analysed (Ca, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb) were usually lower in Fontinalis than Rhynchostegium. Metal concentrations found as a result of the various treatments differed markedly for some metals, including Zn, Cd and Pb. However not one sequence of methods is ideal for all purposes. Criteria that need to be considered when selecting methods include the time and facilities available and whether the moss is to be used for monitoring long-term or short-term pollution.

  2. Uranium accumulation by aquatic plants from uranium-contaminated water in Central Portugal.

    Science.gov (United States)

    Pratas, João; Favas, Paulo J C; Paulo, Carlos; Rodrigues, Nelson; Prasad, M N V

    2012-03-01

    Several species of plants have developed a tolerance to metal that enables them to survive in metal contaminated and polluted sites. Some of these aquatic plants have been reported to accumulate significant amounts of specific trace elements and are, therefore, useful for phytofiltration. This work focuses the potential of aquatic plants for the phytofiltration of uranium (U) from contaminated water. We observed that Callitriche stagnalis, Lemna minor, and Fontinalis antipyretica, which grow in the uraniferous geochemical province of Central Portugal, have been able to accumulate significant amounts of U. The highest concentration of U was found in Callitriche stagnalis (1948.41 mg/kg DW), Fontinalis antipyretica (234.79 mg/kg DW), and Lemna minor (52.98 mg/kg DW). These results indicate their potential for the phytofiltration of U through constructed treatment wetlands or by introducing these plants into natural water bodies in the uraniferous province of Central Portugal. PMID:22567707

  3. Toxic effects of cadmium and zinc on the transmission of Echinoparyphium recurvatum cercariae

    OpenAIRE

    Morley, Neil; Crane, M.; Lewis, J W

    2002-01-01

    The toxicity of cadmium, zinc and Cd/Zn mixtures to the transmission of Echinoparyphium recurvatum (Digenea: Echinostomatidae) cercariae into the snail second intermediate hosts was investigated at concentrations ranging from 100mg l21 to 10 000mg l21 in both soft and hard water. A differential response in the infectivity of metal-exposed cercariae into Lymnaea peregra and Physa fontinalis was demonstrated which was dependent on the snail species being infected. Exposure of L. peregra, P. ...

  4. Los pronombres demostrativos de la lengua chaná (Entre Ríos, Argentina)

    OpenAIRE

    Viegas Barros, J. Pedro

    2012-01-01

    La categoría de los pronombres demostrativos es universal en las lenguas naturales, pero las características funcionales, formales, sintácticas y pragmáticas de estos elementos varían considerablemente de una a otra lengua. El propósito de este trabajo es describir las características funcionales, formales, sintácticas y pragmáticas de los demostrativos en la lengua indígena obsolescente chaná, perteneciente a la familia charrúa, que cuenta actualmente con un último semi-hablante terminal res...

  5. Salmon returns and consumer fitness: growth and energy storage in stream-dwelling salmonids increases with spawning salmon abundance

    Science.gov (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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Olson, Jason; Andersen, Todd

    2005-06-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Todd; Olson, Jason

    2003-03-01

    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.

  9. Saturable triiodothyronine-binding sites in the pituitary nuclei of salmonid teleost fish

    International Nuclear Information System (INIS)

    High-affinity, limited-capacity, 3,5,3'-triiodo-L-thyronine (T3)-binding sites were established by in vitro saturation analysis in cell nuclei of the pituitary gland of arctic charr. The sites were extracted from the purified nuclei using 0.4 M NaCl and incubated with [125I]T3 in the presence of 0.2 M NaCl. T3 saturable binding attained equilibrium after 18-24 hr of incubation at 4 degrees. The association constant ranged from 6.7 to 20.1 liters.mol-1 x 10(9), indicating a T3 affinity greater than that for T3-binding sites in rainbow trout liver. The maximal binding capacity ranged from 0.93 to 2.05 10(-13) mol.mg DNA-1, representing a mean site abundance corresponding to 60% of that for nuclei from trout liver. Thyroxine (T4) completely displaced [125I]T3 in the pituitary nuclei of arctic charr and T3 completely displaced [125I]T4 in the pituitary nuclei of rainbow trout, suggesting that in salmonids both T4 and T3 bind to the same single class of sites. However, the site affinity for T4 was approximately 20-50x less than that for T3. The possible roles of these sites in pituitary function as well as their relationship to other nuclear T3-binding sites in salmonid fish are discussed

  10. 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

    2002-01-01

    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.

  11. Validating methods for measuring delta18O and delta13C in otoliths from freshwater fish.

    Science.gov (United States)

    Guiguer, K R R A; Drimmie, R; Power, M

    2003-01-01

    The ability of the phosphoric acid digestion technique to extract carbon dioxide from biogenic carbonates and reliably reproduce delta(18)O and delta(13)C signatures from standard reference materials (NBS-18, NBS-19) was tested and shown to produce accurate, unbiased measurements of non-biologic materials. The effects of roasting preparation methods commonly reported when analyzing biogenic carbonates were also tested in a series of experiments using reference standards and otoliths obtained from aquacultured Arctic charr and rainbow trout. Roasting had no effect on the isotope measurement of reference standards. No significant differences between mean oxygen isotope signatures from paired experiments with roasted and non-roasted fish otoliths were found. However, otolith oxygen isotope measurements were significantly enriched in comparison to rearing water-based measurements for both species. Agreement between expected isotopic equilibrium and measured otolith delta(18)O values varied as a function of roasting temperature and between species. Criteria for the selection of appropriate roasting temperatures are suggested and favour 350 degrees C in freshwater fish where unbiased estimates of average rearing water temperatures and known differences in rearing temperatures were obtained. Carbon isotopic disequilibria were observed for both species. A mixing model analysis established differences in the percentage of metabolically derived carbon in studied otoliths, with Arctic charr deriving a greater proportion of otolith delta(13)C from metabolism as a result of higher metabolic rates. PMID:12590395

  12. Field and experimental tainting of arctic freshwater fish by crude and refined petroleum products

    International Nuclear Information System (INIS)

    A crude oil spill and a diesel fuel spill in Arctic rivers both resulted in complaints from downstream populations that fish were tainted with an oily taste. Laboratory exposures of fish confirmed the ability of the spilled materials to produce taints in fish. These experiments led to a more systematic study of the relationship between exposure of fish to oil in the water and sensory responses of taste panels. Rainbow trout and arctic charr were exposed to three mixtures of Norman Wells crude oil in water over a 72 h period and then transferred to clean holding tanks for a further 600-840 h. Three fish were removed from each tank at intervals over both the uptake and clearance phases so that rates of production and clearance of the oily taste could be estimated. All panelists were able to discriminate between treated and untreated fish during the uptake and early clearance phases. Some continued to detect tainting in the fish even by the end of the clearance phase. The implication of these taste panel results is that oil tainting is sensitive to dosage of oil, duration of exposure, and duration of post-exposure time in clean water. Arctic charr can be expected to become tainted after an exposure of only a few hours, and to remain tainted for over a month following cessation of exposure. 7 refs., 4 figs

  13. Inferring phylogenetic structure and ancient hybridization within Salmonidae using next-generation sequencing

    Directory of Open Access Journals (Sweden)

    Laurène Alicia Lecaudey

    2015-10-01

    Full Text Available Phylogenetic studies focusing on Salmonidae have thus far revealed significant drawbacks to elucidate some of the interspecific relationships within the family, due to limited number of markers, conflicting phylogenetic signals and hybridization events. In an attempt to resolve these issues, we applied restriction-site associated DNA sequencing (RAD-seq to 44 samples, including 23 different species across the family Salmonidae, with an emphasis on the genus Salvelinus. The aim of our study is to infer reliable interspecific phylogenetic relationships, evaluate several putative scenarios of ancient hybridization and detect possible reticulate patterns of evolution among salmonid fishes. RAD-seq can be particularly useful for systematic studies of closely related taxa, as it provides genome-wide informative characters and allows the detection of introgression. To our knowledge, this is the first next generation sequencing effort applied to salmonid phylogeny and related questions of their evolutionary history. Using the software pipeline pyRAD, we identified 28,402 orthologous loci, which were subsequently used in our downstream analyses. Phylogenetic inferences drawn from a maximum likelihood analysis reveal some interesting results. Salvelinus and Oncorhynchus appear as sister lineages, which contradicts some of the previous phylogenetic analyses. Additionally, despite constituting a separate genus, Salvethymus clusters within the genus Salvelinus, which is consistent with the findings of previous studies and therefore questions its taxonomic status. A monophylum of Salvelinus leucomaenis and Salvelinus levanidovi is the sister group to the remainder of the genus Salvelinus. The genus Parahucho appears as the sister clade to Salmo, which also contradicts some previously published inferences. Finally, we present a practical application of a relatively novel approach to test for putative ancient hybridization events. Since this is the first

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

    Directory of Open Access Journals (Sweden)

    Sans, Mónica

    2005-01-01

    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.

  15. Mercury, lead and cadmium in fish from Lake Norsjø, Southern Norway

    OpenAIRE

    Moreno Vicente, Clara Enedina

    2009-01-01

    Concentrations of mercury (Hg), cadmium (Cd) and lead (Pb) have been investigated in whitefish (Coregonus lavaretus, n = 41), European smelt (Osmerus eperlanus, n = 29), Arctic char (Salvelinus alpinus, n = 27), perch (Perca fluviatilis, n = 26), brown trout (Salmo trutta, n = 22), Atlantic salmon (Salmo salar, n = 14), northern pike (Esox lucius, n = 11), tench (Tinca tinca, n = 4) and crucian carp (Carassius carassius, n = 2), in Lake Norsjø, southern Norway. In addition, the stable isotope...

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

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Todd

    2002-01-01

    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.

  17. Differences between white and red muscle fibers diameter in three salmon fish species

    OpenAIRE

    Karahmet E.; Vileš A.; Katica A.; Mlaćo N.; Toroman A.

    2014-01-01

    Because of skeletal muscle is the main contributor to body weight in most fish, it is probable that the species of the fish is limited by the growth of this tissue. Several aspects of both somatic size and skeletal muscle growth was investigated in this research work included a total of 20 brown trout (Salmo truta m. fario Lineus), 20 brook trout (Salvelinus alpinus) and 20 rainbow trout (Oncorynchus mykkis Walbaum), the average weight of 200 grams. Gathere...

  18. Radioactive contamination of aquatic organisms of the Yenisei river in the area affected by the activity of a Russian plutonium complex

    International Nuclear Information System (INIS)

    The Yenisei River, one of the world's largest rivers, is contaminated with artificial radionuclides released by a Russian facility producing weapons-grade plutonium, which has been in operation for many years. The aim of the study conducted between 1997 and 2003 was to investigate accumulation of artificial radionuclides by aquatic organisms of the Yenisei River and to estimate the exposure dose rates to organisms from various sources. The aquatic plants sampled were of three species: Potamogeton lucens, Fontinalis antipyretica, and Ceratophyllum demersum. The gamma-spectrometric and radiochemical analysis of the samples of aquatic plants for artificial radionuclides has revealed more than 20 long-lived and short-lived radionuclides, including plutonium isotopes. The aquatic animal Phylolimnogammarus viridis and diatoms also contain artificial radionuclides. For most aquatic organisms under study, the dose received from the artificial irradiation is an order of magnitude higher than the dose received from natural irradiation. As Fontinalis antipyretica features the highest capacity to accumulate artificial radionuclides, it accumulates the largest artificial exposure does among the study aquatic organisms (up to 39 μGy/day)

  19. Use of aquatic bryophytes as bio monitors for radioactive studies

    International Nuclear Information System (INIS)

    As a widespread water moss Fontinalis antipyretics is frequently used as a biomonitor for trace elements pollution in lakes and running waters. The purpose of this study is to use Fontinalis antipyretics as a tool for monitoring of radioactivity in waters from different rivers (Musalenska Bistriza, Iskar, Maritza, etc.) in Rila Mountain. The radioactivity of aquatic moss, water samples and sediments were measured using HPG detector with the parameters FWHM 2 kev at 60Co efficiency 35% with low background. The dose rate measurements (μR/h) show different values according to the place of sampling and reflect the present ecological status of the river ecosystems. The ongoing measurements will allowed the absolute value of 137Cs in bryophytes to be determined and eventually some seasonal variations to be observed. A special interest is whether the measured activity is accidental or is as a consequence of a long time accumulation in the bryophytes. In this case they could probably be used for water purification. On that basis the bryophytes could be used for controlling radioactivity of river ecosystems even in high-mountain difficult accessible places replacing the transportation of large volumes of water

  20. Distribution of uranium, americium and plutonium in the biomass of freshwater macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Zotina, T.A.; Kalacheva, G.S.; Bolsunovsky, A.YA. [Institute of Biophysics SB RAS, Akademgorodok, Krasnoyarsk (Russian Federation)

    2010-07-01

    Accumulation of uranium ({sup 238}U), americium ({sup 241}Am) and plutonium ({sup 242}Pu) and their distribution in cell compartments and biochemical components of the biomass of aquatic plants Elodea canadensis, Ceratophyllum demersum, Myrioplyllum spicatum and aquatic moss Fontinalis antipyretica have been investigated in laboratory batch experiments. Isotopes of uranium, americium and plutonium taken up from the water by Elodea canadensis apical shoots were mainly absorbed by cell walls, plasmalemma and organelles. A small portion of isotopes (about 6-13 %) could be dissolved in cytoplasm. The major portion (76-92 %) of americium was bound to cell wall cellulose-like polysaccharides of Elodea canadensis, Myriophyllum spicatum, Ceratophyllum demersum and Fontinalis antipyretica, 8-23 % of americium activity was registered in the fraction of proteins and carbohydrates, and just a small portion (< 1%) in lipid fraction. The distribution of plutonium in the biomass fraction of Elodea was similar to that of americium. Hence, americium and plutonium had the highest affinity to cellulose-like polysaccharides in Elodea biomass. Distribution of uranium in the biomass of Elodea differed essentially from that of transuranium elements: a considerable portion of uranium was recorded in the fraction of protein and carbohydrates (51 %). From our data we can assume that uranium has higher affinity to carbohydrates than proteins. (authors)

  1. Study for the determination of samarium, europium,terbium, dysprosium and yttrium in gadolinium oxide matrix by means of atomic absorption spectrophotometry using a graphite furnace

    International Nuclear Information System (INIS)

    A study for determination of samarium, europium, terbium, dysprosium and yttrium in a gadolinium oxide matrix by atomic absorption spectrophotometry using a graphite furnace is presented. The best charrring and atomization conditions were estabilished for each element, the most convenient ressonance lines being selected as well. The study was carried out for the mentioned lanthanides both when pure and when in binary mixtures with gadolinium, besides those where all for them were together with gadolinium. The determination limits for pure lanthanides were found to be between 1.3 and 9.6 ng assuming a 20% relative standard deviation as acceptable. The detection limits were in the range 0.51 and 7.5 ng, assuming as positive any answer higher than twofold the standard deviation. (author)

  2. New Insights into Fish Ecology via Nuclear Microscopy of Otoliths

    International Nuclear Information System (INIS)

    Otoliths, or earstones, are small, biogenic concretions of aragonitic calcium carbonate precipitated on a protein matrix. Otoliths form part of the hearing and balance system in teleost fishes, and grow as the fish grow, providing a continuous biochronology of growth. Various elements are entrained in minor and trace quantities. In particular, strontium is a useful scalar of habitat use when variable environmental gradients exist. By mapping elemental concentrations and ratios with the Lund nuclear microprobe, we have used strontium in many cases as a proxy for salinity, because Sr:Ca values are roughly an order of magnitude higher in marine vs most fresh waters. In addition, zinc shows strong seasonal variations in salmoniform fishes (salmons, charrs, and whitefishes have been tested to date). We present case studies of several species, and discuss exciting future directions in this research that is revolutionizing fisheries ecology

  3. New Insights into Fish Ecology via Nuclear Microscopy of Otoliths

    Science.gov (United States)

    Limburg, K. E.; Elfman, M.; Kristiansson, P.; Malmkvist, K.; Pallon, J.

    2003-08-01

    Otoliths, or earstones, are small, biogenic concretions of aragonitic calcium carbonate precipitated on a protein matrix. Otoliths form part of the hearing and balance system in teleost fishes, and grow as the fish grow, providing a continuous biochronology of growth. Various elements are entrained in minor and trace quantities. In particular, strontium is a useful scalar of habitat use when variable environmental gradients exist. By mapping elemental concentrations and ratios with the Lund nuclear microprobe, we have used strontium in many cases as a proxy for salinity, because Sr:Ca values are roughly an order of magnitude higher in marine vs most fresh waters. In addition, zinc shows strong seasonal variations in salmoniform fishes (salmons, charrs, and whitefishes have been tested to date). We present case studies of several species, and discuss exciting future directions in this research that is revolutionizing fisheries ecology.

  4. Uptake of uranium by native aquatic plants: potential for bioindication and phytoremediation

    Directory of Open Access Journals (Sweden)

    Favas P. J. C.

    2013-04-01

    Full Text Available The work presented here is a part the on going study on the uraniferous geochemical province of Central Portugal in which, the use of aquatic plants as indicators of uranium contamination is being probed using aquatic plants emphasizing their potential use in the emerging phytotechnologies. Even though we have observed very low concentration of U in the fresh waters of the studied sites we found a set of vegetable species with the ability to accumulate U in concentrations which are orders of magnitude higher than the surrounding environment. We have observed that Apium nodiflorum, Callitriche stagnalis, Lemna minor and Fontinalis antipyretica accumulated significant amounts of uranium, whereas Oenanthe crocata excluded U. These results indicate substantial scope for proper radiophytoremediation and phytosociological investigation exploiting the native flora. These species show great potential for phytoremediation because they are endemic and easy to grow in their native conditions. A. nodiflorum and C. stagnalis have high bioproductivity and yield good biomass.

  5. Radioactivity measurements of the Danube area taken by the Federal Institute of Water Quality during 1975-1978

    International Nuclear Information System (INIS)

    A review is given of the gross-β-, K- and gross-α-activity of the Austrian section of the river Danube, measured by the Federal Institute of Water Quality in Vienna during 1975 - 1978. The results of the tributaries to the Danube: Inn, March and Leitha are even discussed. Beside water samples the activity level in acquatic biota such as plankton, resp. seston, algae, fontinalis and fish as well as in grass and soil was studied. The investigations showed, that the radioactive burden of the Danube and her tributaries and especially the maxima of activity have slightly decreased from 1975 to 1978 corresponding to the decrease in number and force of the Chinese nuclear weapon tests. (author)

  6. Background concentrations of heavy metals in aquatic bryophytes used for biomonitoring in basaltic areas (a case study from central France)

    Energy Technology Data Exchange (ETDEWEB)

    Samecka-Cymerman, A. [Wroclaw Univ. (Poland). Dept. of Ecology and Nature Protection; Kempers, A.J. [Nijmegen Univ. (Netherlands). Dept. of Aquatic Ecology and Biogeology

    1999-12-01

    Studies were made of the aquatic bryophytes Fontinalis antipyretica Hedw., Plathypnidium rusciforme (Neck.)Fleisch and Chiloscyphus sp. (Hoffm.)Dum. from streams embedded in basaltic rocks (Le Puy, central France). Water from these streams possessed elevated levels of Cu, Zn, Sr, V, Ba, Ni and Co, reflecting the geochemistry of the basalts, a basic type of igneous rocks containing elevated levels of these elements. The concentration of elements in bryophytes is correlated to the chemical composition of water of their sampling sites. Contents of trace elements in plants were higher than background values. The elevated levels of these elements possibly caused disturbances in the ionic equilibrium within the bryophytes. The molar ratio between contents of Ca and Mg in water (from 0.44 to 1) was different from that typical for natural water. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Todd [Kalispel Natural Resource Department

    2009-07-08

    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.

  8. Habitatbruk og næringsøkologi til fiskearter i et komplekst samfunn med dominans av abbor (Perca fluviatilis)

    OpenAIRE

    Haugerud, Eivind

    2011-01-01

    Denne masteroppgavens formål har vært å klarlegge relativ bestandsmengde, habitatbruk og næringsøkologi til de enkelte artene i fiskesamfunnet i Skasen, i første rekke for å få bedre innsikt i bestandstilstanden til røye (Salvelinus alpinus) i et komplekst fiskesamfunn med abbor (Perca fluviatilis), mort (Rutilus rutilus), lake (Lota lota), gjedde (Esox lucius) og ørret (Salmo trutta). Innsamling av fisk ble gjennomført i juni, juli, august og september 2010 med garnserier satt i litora...

  9. 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)

    1996-06-01

    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}

  10. Fat content of the flesh of siscowets and lake trout from Lake Superior

    Science.gov (United States)

    Eschmeyer, Paul H.; Phillips, Arthur M., Jr.

    1965-01-01

    Samples of flesh were excised from the middorsal region of 67 siscowets (Salvelinus namaycush siscowet) and 46 lake trout (Salvelinus n. namaycush) collected from Lake Superior. Chemical analysis of the samples revealed a range in fat content (dry weight) of 32.5 to 88.8 per cent in siscowets and 6.6 to 52.3 per cent in lake trout. Percentage fat increased progressively with increase in length of fish in both forms, but the average rate of increase was far greater for siscowets than for lake trout at lengths between 12 and 20 inches. Despite substantial individual variation, the percentage fat in the two forms was widely different and without overlap at all comparable lengths. The range in iodine number of the fat was 100 to 160 for siscowets and 103 to 161 for lake trout; average values were generally lower for siscowets than for lake trout among fish of comparable length. Percentage fat and relative weight were not correlated significantly in either subspecies. The fat content of flesh samples from a distinctive subpopulation of Lake Superior lake trout known as 'humpers' was more closely similar to that of typical lean lake trout than to siscowets, but the rate of increase in fat with increasing length was greater than for lean lake trout. Flesh samples from hatchery-reared stocks of lake trout, hybrid lake trout X siscowets, and siscowets tended to support the view that the wide difference in fat content between siscowets and lake trout is genetically determined.

  11. Temperature-mediated differences in bacterial kidney disease expression and survival in Renibacterium salmoninarum-challenged bull trout and other salmonids

    Science.gov (United States)

    Jones, D.T.; Moffitt, C.M.; Peters, K.K.

    2007-01-01

    Resource managers considering restoration and reconnection of watersheds to protect and enhance threatened populations of bull trout Salvelinus confluentus have little information about the consequences of bacterial kidney disease (BKD) caused by Renibacterium salmoninarum. To better understand the response of bull trout to R. salmoninarum challenge, we conducted several laboratory experiments at two water temperatures. The extent, severity, and lethality of BKD in bull trout were compared with those of similarly challenged lake trout S. namaycush, Arctic char S. alpinus, Chinook salmon Oncorhynchus tshawytscha, and rainbow trout O. mykiss. The lethal dose of bacterial cells necessary to induce 50% mortality (LD50) was 10-fold lower at the 15??C challenge than at the 9??C challenge. Of the species tested, bull trout were relatively resistant to BKD, Arctic char were the most susceptible among Salvelinus species, and Chinook salmon were the most susceptible among Oncorhynchus species tested. Mean time to death was more rapid for all fish tested at 15??C than for fish challenged at 9??C. These results suggest that infection of bull trout with BKD likely poses a low risk to successful restoration of threatened populations. ?? Copyright by the American Fisheries Society 2007.

  12. Body ion loss as a bioindicator of water quality impaired by coal mining

    International Nuclear Information System (INIS)

    Protection of surface waters receiving discharges from coal mines is currently based on performance standards set by the EPA after passage of the Clean Water Act. These standards were technology-driven and reflect the Best Achievable Control Technology (BAT) available at the time of promulgation. Changes proposed as part of the upcoming reauthorization of the US Clean Water Act suggest that such technology-based standards may be reevaluated in light of more recent information on the toxicological effect of mine discharges on aquatic biota. The authors present here a physiological-based method for evaluating the site-specific toxicity of mine-derived discharges into receiving waters. They tested the usefulness of the body ion loss rate bioassay by exposing fathead minnows, brook charr and stoneflies to coal mine-impacted waters (elevated acidity and trace metals) in the field and to artificial mine water (AMW) in the laboratory. Body ion loss rate was significantly correlated with levels of mine pollution in the field. Body ion loss measured in AMW revealed strong interactions between metals and acid. Because the test animals exhibited differing levels of sensitivity to mine discharge, the selection of an appropriate organism for the body ion loss bioassay may vary depending on the (1) physical characteristics, (2) chemical characteristics and (3) pre-existing level of mine impact of the receiving waters

  13. Uranium accumulation in aquatic macrophytes in an uraniferous region: Relevance to natural attenuation.

    Science.gov (United States)

    Cordeiro, Cristina; Favas, Paulo J C; Pratas, João; Sarkar, Santosh Kumar; Venkatachalam, Perumal

    2016-08-01

    Phytoremediation potential of uranium (U) was investigated by submerged, free-floating and rooted emergent native aquatic macrophytes inhabiting along the streams of Horta da Vilariça, a uraniferous geochemical region of NE Portugal. The work has been undertaken with the following objectives: (i) to relate the U concentrations in water-sediment-plant system; and (ii) to identify the potentialities of aquatic plants to remediate U-contaminated waters based on accumulation pattern. A total of 25 plant species culminating 233 samples was collected from 15 study points along with surface water and contiguous sediments. Concentrations of U showed wide range of variations both in waters (0.61-5.56 μg L(-1), mean value 1.98 μg L(-1)) and sediments (124-23,910 μg kg(-1), mean value 3929 μg kg(-1)) and this is also reflected in plant species examined. The plant species exhibited the ability to accumulate U several orders of magnitude higher than the surrounding water. Maximum U concentrations was recorded in the bryophyte Scorpiurium deflexifolium (49,639 μg kg(-1)) followed by Fontinalis antipyretica (35,771 μg kg(-1)), shoots of Rorippa sylvestris (33,837 μg kg(-1)), roots of Oenanthe crocata (17,807 μg kg(-1)) as well as in Nasturtium officinale (10,995 μg kg(-1)). Scorpiurium deflexifolium displayed a high bioconcentration factor (BF) of ∼2.5 × 10(4) (mean value). The species Fontinalis antipyretica, Nasturtium officinale (roots) and Rorippa sylvestris (shoots) exhibited the mean BFs of 1.7 × 10(4), 5 × 10(3) and 4.8 × 10(3) respectively. Maximum translocation factor (TF) was very much pronounced in the rooted perennial herb Rorippa sylvestris showing extreme ability to transport U for the shoots and seems to be promising candidate to be used as bioindicator species. PMID:27164268

  14. BIO-MONITORING FOR URANIUM USING STREAM-SIDE TERRESTRIAL PLANTS AND MACROPHYTES

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, E.; Duff, M.; Hicks, T.; Coughlin, D.; Hicks, R.; Dixon, E.

    2012-01-12

    This study evaluated the abilities of various plant species to act as bio-monitors for environmental uranium (U) contamination. Vegetation and soil samples were collected from a U processing facility. The water-way fed from facility storm and processing effluents was the focal sample site as it represented a primary U transport mechanism. Soils and sediments from areas exposed to contamination possessed U concentrations that averaged 630 mg U kg{sup -1}. Aquatic mosses proved to be exceptional accumulators of U with dry weight (dw) concentrations measuring as high as 12500 mg U kg{sup -1} (approximately 1% of the dw mass was attributable to U). The macrophytes (Phragmites communis, Scripus fontinalis and Sagittaria latifolia) were also effective accumulators of U. In general, plant roots possessed higher concentrations of U than associated upper portions of plants. For terrestrial plants, the roots of Impatiens capensis had the highest observed levels of U accumulation (1030 mg kg{sup -1}), followed by the roots of Cyperus esculentus and Solidago speciosa. The concentration ratio (CR) characterized dry weight (dw) vegetative U levels relative to that in associated dw soil. The plant species that accumulated U at levels in excess of that found in the soil were: P. communis root (CR, 17.4), I. capensis root (CR, 3.1) and S. fontinalis whole plant (CR, 1.4). Seven of the highest ten CR values were found in the roots. Correlations with concentrations of other metals with U were performed, which revealed that U concentrations in the plant were strongly correlated with nickel (Ni) concentrations (correlation: 0.992; r-squared: 0.984). Uranium in plant tissue was also strongly correlated with strontium (Sr) (correlation: 0.948; r-squared: 0.899). Strontium is chemically and physically similar to calcium (Ca) and magnesium (Mg), which were also positively-correlated with U. The correlation with U and these plant nutrient minerals, including iron (Fe), suggests that active

  15. Fish resource data from the Snare River, Northwest Territories

    International Nuclear Information System (INIS)

    An extensive fish sampling and tagging program was conducted on the Snare River, Northwest Territories, in order to collect baseline data on the fish populations in sections of the river altered by hydroelectric projects. Fish populations were sampled from May to July 1977 in five sections of the river that were influenced by development of hydropower at three dams currently on line; 530 tagged fish were also released. The biweekly catch composition in experimental gill nets for each study area and the catch per gill net mesh size are presented for walleye (Stizostedion vitreum), lake trout (Salvelinus namaycush), lake whitefish (Coregonus clupeaformis), lake cisco (Coregonus artedi), northern pike (Esox lucius), white sucker (Catostomus commersoni), and longnose sucker (Catostomus catostomus). Age-specific data on length, weight, age, sex, and maturity are also included. 7 refs., 12 figs., 42 tabs

  16. Status of Oregon's Bull Trout.

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Graves, Suzy

    1992-02-01

    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.

  18. Acute toxicities to larval rainbow trout of representative compounds detected in Great Lakes fish

    Science.gov (United States)

    Edsall, Carol Cotant

    1991-01-01

    In recent years the National Fisheries Research Center-Great Lakes has ranked the potential hazard to fish and invertebrates of various chemical compounds detected in two Great Lakes fishes-- lake trout, Salvelinus namaycush, and walleye, Stizostedion vitreum vitreum (Hesselberg and Seelye 1982). This hazard assessment has included the identification of the potential sources of the compounds, determination of the occurrence and abundance of the compounds in Great Lakes fish, and the determination of acute toxicities of representative compounds of 19 chemical classes (Passino and Smith 1987a). In further studies Smith et al. (1988) focused on 6 of the 19 classes of compounds using the zooplankter Daphnia pulex as the test organism. They ranked the six classes as follows (in decreasing order of toxicity): polycyclic aromatic hydrocarbons (PAHs), alkyl halides, nitrogen-containing compounds, cyclic alkanes, heterocyclic nitrogen compounds, and silicon-containing compounds.

  19. What are the toxicological effects of mercury in Arctic biota?

    Science.gov (United States)

    Dietz, Rune; Sonne, Christian; Basu, Niladri; Braune, Birgit; O'Hara, Todd; Letcher, Robert J; Scheuhammer, Tony; Andersen, Magnus; Andreasen, Claus; Andriashek, Dennis; Asmund, Gert; Aubail, Aurore; Baagøe, Hans; Born, Erik W; Chan, Hing M; Derocher, Andrew E; Grandjean, Philippe; Knott, Katrina; Kirkegaard, Maja; Krey, Anke; Lunn, Nick; Messier, Francoise; Obbard, Marty; Olsen, Morten T; Ostertag, Sonja; Peacock, Elizabeth; Renzoni, Aristeo; Rigét, Frank F; Skaare, Janneche Utne; Stern, Gary; Stirling, Ian; Taylor, Mitch; Wiig, Øystein; Wilson, Simon; Aars, Jon

    2013-01-15

    This review critically evaluates the available mercury (Hg) data in Arctic marine biota and the Inuit population against toxicity threshold values. In particular marine top predators exhibit concentrations of mercury in their tissues and organs that are believed to exceed thresholds for biological effects. Species whose concentrations exceed threshold values include the polar bears (Ursus maritimus), beluga whale (Delphinapterus leucas), pilot whale (Globicephala melas), hooded seal (Cystophora cristata), a few seabird species, and landlocked Arctic char (Salvelinus alpinus). Toothed whales appear to be one of the most vulnerable groups, with high concentrations of mercury recorded in brain tissue with associated signs of neurochemical effects. Evidence of increasing concentrations in mercury in some biota in Arctic Canada and Greenland is therefore a concern with respect to ecosystem health. PMID:23231888

  20. Toxicity of fluoride to aquatic species and evaluation of toxicity modifying factors.

    Science.gov (United States)

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

    2015-07-01

    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. PMID:25732700

  1. Longevity of Lake Superior lake trout

    Science.gov (United States)

    Schram, Stephen T.; Fabrizio, Mary C.

    1998-01-01

    The age structure of mature lake trout Salvelinus namaycush from the Wisconsin waters of Lake Superior increased following a population recovery that has taken place since the 1960s. As the population aged, it became apparent that scales were unreliable aging structures. Beginning in 1986, we examined both scale and sagittal otolith ages from tagged fish with a known period at liberty. We found large discrepancies in scale and sagittal otolith ages of mature fish, such that scale ages were biased low. We estimated lake trout living up to 42 years, which is greater than previously reported from Lake Superior. Investigators studying lake trout population dynamics in the Great Lakes should be aware that lake trout can live longer than previously thought.

  2. A blood chemistry profile for lake trout

    Science.gov (United States)

    Edsall, Carol Cotant

    1999-01-01

    A blood chemistry profile for lake trout Salvelinus namaycush was developed by establishing baseline ranges for several clinical chemistry tests (glucose, total protein, amylase, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, creatine kinase, calcium, and magnesium). Measurements were made accurately and rapidly with a Kodak Ektachem DT60 Analyzer and the Ektachem DTSC Module. Blood serum was collected from both laboratory-reared lake trout (1978 and 1986 year-classes) and feral spawning trout from Lake Michigan and then analyzed in the laboratory. No clinically significant differences were found between samples analyzed fresh and those frozen for 1 or 6 weeks. The ranges in chemistry variables for feral lake trout were generally wider than those for laboratory-reared lake trout, and significant differences existed between male and female feral lake trout for several tests. Blood chemistry profiles also varied seasonally on fish sampled repeatedly.

  3. Assessing the feasibility of native fish reintroductions: a framework and example applied to bull trout in the Clackamas River, Oregon

    Science.gov (United States)

    Dunham, Jason B.; Gallo, Kirsten

    2008-01-01

    In a species conservation context, translocations can be an important tool, but they frequently fail to successfully establish new populations. We consider the case of reintroductions for bull trout (Salvelinus confluentus), a federally-listed threatened species with a widespread but declining distribution in western North America. Our specific objectives in this work were to: 1) develop a general framework for assessing the feasibility of reintroduction for bull trout, 2) provide a detailed example of implementing this framework to assess the feasibility of reintroducing bull trout in the Clackamas River, Oregon, and 3) discuss the implications of this effort in the more general context of fish reintroductions as a conservation tool. Review of several case histories and our assessment of the Clackamas River suggest that an attempt to reintroduce bull trout could be successful, assuming adequate resources are committed to the subsequent stages of implementation, monitoring, and evaluation.

  4. Metals in fish scales collected in Lake Opeongo, Canada, from 1939 to 1979

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, M.G. (Dept. of Fisheries and Oceans, Burlington, Ontario (Canada))

    1989-05-01

    Time series (1939-1979) of metal concentrations in historical collections of scales from lake trout Salvelinus namaycush and smallmouth bass Micropterus dolomieui from Lake Opeongo, Canada, were compared with temporal trends in metal concentration profiles in core samples of profundal lake sediment. There was no trend for Zn in scales. Elevated Cu and Hg concentrations occurred early in the study period in both species. Elevated Cd was found in the earliest year in smallmouth bass scales. Temporal trends in Hg (and possibly Cd) in smallmouth bass scales probably were attributable to differences in fish weight among years. The data did not support the hypothesis that temporal trends in metal loadings entering lakes are reflected by fish tissue concentrations.

  5. 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;

    2000-01-01

    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...

  6. Accumulation of arsenic by aquatic plants in large-scale field conditions: opportunities for phytoremediation and bioindication.

    Science.gov (United States)

    Favas, Paulo J C; Pratas, João; Prasad, M N V

    2012-09-01

    This work focuses on the potential of aquatic plants for bioindication and/or phytofiltration of arsenic from contaminated water. More than 71 species of aquatic plants were collected at 200 sampling points in running waters. The results for the 18 most representative plant species are presented here. The species Ranunculus trichophyllus, Ranunculus peltatus subsp. saniculifolius, Lemna minor, Azolla caroliniana and the leaves of Juncus effusus showed a very highly significant (P<0.001) positive correlation with the presence of arsenic in the water. These species may serve as arsenic indicators. The highest concentration of arsenic was found in Callitriche lusitanica (2346 mg/kg DW), Callitriche brutia (523 mg/kg DW), L. minor (430 mg/kg DW), A. caroliniana (397 mg/kg DW), R. trichophyllus (354 mg/kg DW), Callitriche stagnalis (354 mg/kg DW) and Fontinalis antipyretica (346 mg/kg DW). These results indicate the potential application of these species for phytofiltration of arsenic through constructed treatment wetlands or introduction of these plant species into natural water bodies. PMID:22820614

  7. Using devitalized moss for active biomonitoring of water pollution.

    Science.gov (United States)

    Debén, S; Fernández, J A; Carballeira, A; Aboal, J R

    2016-03-01

    This paper presents the results of an experiment carried out for the first time in situ to select a treatment to devitalize mosses for use in active biomonitoring of water pollution. Three devitalizing treatments for the aquatic moss Fontinalis antipyretica were tested (i.e. oven-drying at 100 °C, oven-drying with a 50-80-100 °C temperature ramp, and boiling in water), and the effects of these on loss of material during exposure of the transplants and on the accumulation of different heavy metals and metalloids were determined. The suitability of using devitalized samples of the terrestrial moss Sphagnum denticulatum to biomonitor aquatic environments was also tested. The structure of mosses was altered in different ways by the devitalizing treatments. Devitalization by boiling water led to significantly less loss of material (p < 0.01) than the oven-drying treatments. However, devitalization by oven-drying with a temperature ramp yielded more stable results in relation to both loss of material and accumulation of elements. With the aim of standardizing the moss bag technique, the use of F. antipyretica devitalized by oven-drying with a temperature ramp is recommended, rather than other devitalization treatments or use of S. denticulatum. PMID:26803787

  8. The effects of disturbance events on the submerged bryophyte vegetation in the streams of the tatra mountains Slovakia

    International Nuclear Information System (INIS)

    Submerged bryophytes are often important constituents of stream vegetation. Almost the whole area of the Tatra mountains (The West Carpathians, 28 streams) has been surveyed by a large number of sampling sites (78) at altitudes between 639 - 2002 m a.s.l. The lower parts of the streams are mostly the areas with disturbance events - roads, clearings, built up areas, avalanche sites, bark beetles infection, wind-thrown trees and ski resorts. Conductivity, pH, dissolved oxygen, redox potential, chemical oxygen demand, calcium carbonate, nitrates, ammonia and chlorides were plotted as ordination axes, for their ecological interpretation, disturbance events were plotted onto CCA ordination diagram. Only bryophytes recorded = 3 times in the streams have been submitted to ordination analyses: Scapania undulata (L.) Dumort., Brachythecium rivulare B. S. G., Fontinalis antipyretica Hedw., Hygrohypnum luridum (Hedw.) Jenn., Hygrohypnum ochraceum (Wilson) Loeske, Palustriella commutata (Hedw.) Ochyra and Platyhypnidium riparioides (Hedw.) Bruch and Schimp. Correlation between disturbance events and bryophytes was seen, shown by Canonical Correspondence Analysis CCA. In the term of heavy metal accumulation, the aquatic bryoflora is relatively well investigated, this is not true in terms of nutrient preferences or tolerances. This is why we have decided to fill this knowledge gap. We have found, that natural and anthropogenic disturbance events result in extra input of nutrients. (author)

  9. Optimization of conditions for the extraction of phorbol esters from Jatropha oil

    Energy Technology Data Exchange (ETDEWEB)

    Devappa, Rakshit K.; Makkar, H.P.S.; Becker, K. [Institute for Animal Production in the Tropics and Subtropics (480b), University of Hohenheim, 70593 Stuttgart (Germany)

    2010-08-15

    The production of Jatropha curcas seeds as a biodiesel feedstock is expected to reach 160 Mt by 2017. The present study aims at extracting phorbol esters (PEs) as a co-product from Jatropha oil before processing it to biodiesel. The conditions were optimized for extraction of PEs in organic solvents by using a magnetic stirrer and an Ultra turrax. The extent of reduction in PEs was >99.4% in methanol using any of the stirring tools. However, the extraction using Ultra turrax affected considerably the colour of the remaining oil. Therefore, further solvent:oil ratio, time and temperature were optimized using a magnetic stirrer to get PE rich fraction-I (48.4 mg PEs g{sup -1}) and virtually PE-free oil. PEs were 14 fold higher in this fraction than the control oil. PEs, extracted in methanol from the untreated Jatropha oil, at 1 mg L{sup -1} produced 100% mortality in snails (Physa fontinalis). The methanol extract from virtually PE-free oil when concentrated 20 and 25 time the untreated Jatropha oil (equivalent of 20 mg L{sup -1} and 25 mg L{sup -1} PEs in the control oil) was nontoxic to snails. PE rich fraction-I, obtained as a co-product, can be used in agricultural, medicinal and pharmaceutical applications and the remaining oil can be used for biodiesel preparation. The remaining oil will be friendly to the environment and workers. (author)

  10. Accumulation of uranium by aquatic plants in field conditions: prospects for phytoremediation.

    Science.gov (United States)

    Favas, Paulo J C; Pratas, João; Varun, Mayank; D'Souza, Rohan; Paul, Manoj S

    2014-02-01

    A study was undertaken to determine Uranium concentrations in water and aquatic plants in the uraniferous region of Beiras, Central Portugal. Samples were collected from running water (n=200) at places where aquatic species were observed. Plant samples were collected from 28 species of submerged, free-floating and rooted emergent plants including 2 bryophytes and 1 pteridophyte. Uranium concentrations in surface waters ranged from 0.23 to 1,217 μg L(-1). The aquatic plant species studied, including several previously untested species, exhibited the ability to accumulate U in concentrations many times that of the ambient water. In general submerged plants exhibited higher U content followed by rooted emergent and free floating species. The highest U concentrations were observed in the bryophyte Fontinalis antipyretica (up to 4,979 mg kg(-1)) followed by Callitriche stagnalis (1963mgkg(-1)), Callitriche hamulata (379 mg kg(-1)), Ranunculus peltatus subsp. saniculifolius (243 mg kg(-1)), Callitriche lusitanica (218 mg kg(-1)), and Ranunculus trichophyllus (65.8 mg kg(-1)). In two out of three rooted emergent species U seemed to be preferentially partitioned in rhizome/roots with highest rhizome U content recorded in Typha latifolia (380 mg kg(-1)). Among the free-floating species, the highest U content (42.5 mg kg(-1)) was seen in Lemna minor. The bryophyte F. antipyretica and Callitrichaceae members seem to be promising candidates for the development of phytofiltration methodologies based on U accumulation, abundance and biomass production. PMID:24239820

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

    Directory of Open Access Journals (Sweden)

    Zafar I. Chaudhry

    2011-05-01

    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%.

  12. The role of lake-specific abiotic and biotic factors for the transfer of radiocaesium fallout to fish

    International Nuclear Information System (INIS)

    Lake-specific factors are used as a tool to explain the variation in transfer of 137Cs to fish at a certain level of fallout, and to describe and evaluate the temporal development of this transfer. The effect of biotic interrelationships and environmental variables influencing the trophic structure of the lakes is briefly reviewed and discussed. The study is based on a large amount of existing Nordic post-Chernobyl data on 137Cs in different species of freshwater fish. The maximum transfer was reached within the first three years for all species in most lakes and normally in the order; small perch - trout and charr - larger perch - pike, a sequence that seems to reflect the trophic level each species occupies. Thus, the fish-eating pike is the species with the most extended temporal development and is also the species with the highest values of total time-integrated transfer. The transfer to fish differed over an order of magnitude between lakes, and lakes with a high total transfer to small perch also show a high total transfer to pike. Inter-lake differences in this respect could not be explained by the difference in growth rate of pike between lakes. Information is provided about the ranges for the total transfer to some common fish specied in Nordic waters at different ranges of the theoretical residence time of 137Cs in lake waters (TCs). TCs is determined from the mean hydraulic residence time and the scavenging capacity of the lakes. The amount and nature of scavenging agents (possibly clay minerals) were well indicated, but not determined, by the natural concentration of base cations in lake water. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Golik Silvina Inés

    2003-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    A. M. Snow

    2008-01-01

    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.

  15. Comparative analysis of the mobility of uranium and artificial radionuclides in the ecosystem of the Yenisei River

    Energy Technology Data Exchange (ETDEWEB)

    Bolsunovsky, Alexander; Medvedeva, Marina [Institute of Biophysics SB Russian Academy of Sciences, 660036, Krasnoyarsk (Russian Federation)

    2014-07-01

    The Yenisei River is one of the largest rivers in the world, which had been subjected to radioactive contamination for over 50 years, due to operation of the Mining-and-Chemical Combine (MCC) of Rosatom at Zheleznogorsk, which had been producing weapons-grade plutonium. Bottom sediments and flood plain of the Yenisei River are contaminated by artificial radionuclides, including transuranium ones, both close to the MCC and at a considerable distance downstream. The MCC is also a source of uranium isotopes in the Yenisei. Thus, the Yenisei River basin is a unique environment for studying the mobility of both uranium isotopes and artificial radionuclides in all components of the aquatic ecosystem. The purpose of this study was to compare the mobility of uranium and artificial radionuclides in the ecosystem of the Yenisei River. Samples of water, sediments, and aquatic organisms were used as study material. Aquatic organisms were represented by submerged plants, benthic-feeding fish, and zoo-benthos. The submerged plants (macrophytes) analyzed were of five species: Fontinalis antipyretica, Potamogeton lucens, Ceratophyllum demersum, Myriophyllum spicatum, and Elodea canadensis. Grayling (Timalus arcticus) represented benthic-feeding fish, and zoo-benthos species were represented by Philolimnogammarus viridis, which forms the major part of the grayling's diet. Samples were collected at positions in the vicinity of the MCC discharge point, at a distance of 110 km downstream of Krasnoyarsk, and upstream of the MCC, during sampling campaigns in 2008-2012. Radionuclide measurements were performed using a wide range of instrumental methods: gamma-spectrometry with a 'Canberra' spectrometer (U.S.), mass spectrometry with an 'Agilent' spectrometer (U.S.), neutron activation analysis, and beta-alpha radiometry. The results obtained in this study suggest that the part of the Yenisei River ecosystem contaminated due to MCC radioactive discharges contains

  16. The effect of radioactive contamination of the Yenisei river on cytogenetic characteristics of aquatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Bolsunovsky, A.; Medvedeva, M. [Institute of Biophysics SB Russian Academy of Sciences (Russian Federation); Muratova, E. [Institute of Forest SB Russian Academy of Sciences (Russian Federation)

    2014-07-01

    The Yenisei River, one of the world's largest rivers, is contaminated with artificial radionuclides released by one of the Russian facilities producing weapons-grade plutonium (the Mining-and-Chemical Combine, MCC), which has been in operation for many years. Aquatic plants are an important component of water ecosystems, which can accumulate high levels of radionuclides and, thus, can be used in bio-monitoring and bioremediation. The purpose of the study was to assess levels of radionuclides and to evaluate the frequency of chromosomal aberrations in samples of submerged plants collected in different parts of the Yenisei River. The following species were studied: Fontinalis antipyretica, Batrachium kauffmanii, Myriophyllum spicatum, Elodea canadensis, Ceratophyllum demersum and various Potamogeton species. Samples were collected at positions in the vicinity of the MCC discharge point, at a distance of 330 km downstream of Krasnoyarsk, and upstream of the MCC, during sampling campaigns in 2003-2012. Detailed analysis of radioactive contamination of aquatic plants of the Yenisei River revealed large-scale contamination of aquatic plants as far as 250 km downstream of the MCC. Before the last MCC reactor was shut down in 2010, about 30 radionuclides, including uranium and transuranium elements, were detected in the biomass of aquatic plants. The highest concentration factors of the major radionuclides were obtained for Fontinalis antipyretica and Potamogeton lucens. Samples of the plants collected after the shutdown of the reactor contained considerably lower activity levels of artificial radionuclides, and their diversity was significantly decreased. Results of cytogenetic investigations of aquatic plants collected when the reactor was still operating (2003-2009) suggest that at the MCC discharge site and downstream the occurrence of chromosomal aberrations in ana-telophase and metaphase cells of the plants was considerably higher (up to 30%) than in the control

  17. Comparative analysis of the mobility of uranium and artificial radionuclides in the ecosystem of the Yenisei River

    International Nuclear Information System (INIS)

    The Yenisei River is one of the largest rivers in the world, which had been subjected to radioactive contamination for over 50 years, due to operation of the Mining-and-Chemical Combine (MCC) of Rosatom at Zheleznogorsk, which had been producing weapons-grade plutonium. Bottom sediments and flood plain of the Yenisei River are contaminated by artificial radionuclides, including transuranium ones, both close to the MCC and at a considerable distance downstream. The MCC is also a source of uranium isotopes in the Yenisei. Thus, the Yenisei River basin is a unique environment for studying the mobility of both uranium isotopes and artificial radionuclides in all components of the aquatic ecosystem. The purpose of this study was to compare the mobility of uranium and artificial radionuclides in the ecosystem of the Yenisei River. Samples of water, sediments, and aquatic organisms were used as study material. Aquatic organisms were represented by submerged plants, benthic-feeding fish, and zoo-benthos. The submerged plants (macrophytes) analyzed were of five species: Fontinalis antipyretica, Potamogeton lucens, Ceratophyllum demersum, Myriophyllum spicatum, and Elodea canadensis. Grayling (Timalus arcticus) represented benthic-feeding fish, and zoo-benthos species were represented by Philolimnogammarus viridis, which forms the major part of the grayling's diet. Samples were collected at positions in the vicinity of the MCC discharge point, at a distance of 110 km downstream of Krasnoyarsk, and upstream of the MCC, during sampling campaigns in 2008-2012. Radionuclide measurements were performed using a wide range of instrumental methods: gamma-spectrometry with a 'Canberra' spectrometer (U.S.), mass spectrometry with an 'Agilent' spectrometer (U.S.), neutron activation analysis, and beta-alpha radiometry. The results obtained in this study suggest that the part of the Yenisei River ecosystem contaminated due to MCC radioactive discharges contains both artificial

  18. The impact of an industrial effluent on the water quality, submersed macrophytes and benthic macroinvertebrates in a dammed river of Central Spain.

    Science.gov (United States)

    Gonzalo, Cristina; Camargo, Julio A

    2013-10-01

    This research was conducted in the middle Duratón River (Central Spain), in the vicinity of Burgomillodo Reservoir. An industrial effluent enters the river 300 m downstream from the dam. Fluoride and turbidity levels significantly increased downstream from the effluent, these levels being to some extent affected by differential water releases from the dam. The community of submersed macrophytes exhibited slighter responses and, accordingly, lower discriminatory power than the community of benthic macroinvertebrates, this indicating that metrics and indices based on macroinvertebrates may be more suitable for the biological monitoring of water pollution and habitat degradation in dammed rivers receiving industrial effluents. However, in relation to fluoride bioaccumulation at the organism level, macrophytes (Fontinalis antipyretica and Potamogeton pectinatus) were as suitable bioindicators of fluoride pollution as macroinvertebrates (Ancylus fluviatilis and Pacifastacus leniusculus). Fluoride bioaccumulation in both hard and soft tissues of these aquatic organisms could be used as suitable bioindicator of fluoride pollution (even lower than 1 mg F(-)L(-1)) in freshwater ecosystems. Echinogammarus calvus exhibited a great sensitivity to the toxicity of fluoride ions, with a 96 h LC₅₀ of 7.5 mg F(-)L(-1) and an estimated safe concentration of 0.56 mg F(-)L(-1). The great capacity of E. calvus to take up and retain fluoride during exposures to fluoride ions would be a major cause of its great sensitivity to fluoride toxicity. It is concluded that the observed fluoride pollution might be partly responsible for the absence of this native amphipod downstream from the industrial effluent. PMID:23830885

  19. Plutonium concentration and 240Pu/239Pu atom ratio in biota collected from Amchitka Island, Alaska: recent measurements using ICP-SFMS

    International Nuclear Information System (INIS)

    Three underground nuclear tests, including the Unites States' largest, were conducted on Amchitka Island, Alaska. Monitoring of the radiological environment around the island is challenging because of its remote location. In 2008, the Department of Energy (DOE) Office of Legacy Management (LM) became responsible for the long term maintenance and surveillance of the Amchitka site. The first DOE LM environmental survey occurred in 2011 and is part of a cycle of activities that will occur every 5 years. The University of Alaska Fairbanks, a participant in the 2011 study, provided the lichen (Cladonia spp.), freshwater moss (Fontinalis neomexicanus), kelp (Eualaria fistulosa) and horse mussel (Modiolus modiolus) samples from Amchitka Island and Adak Island (a control site). These samples were analyzed for 239Pu and 240Pu concentration and 240Pu/239Pu atom ratio using inductively coupled plasma sector field mass spectrometry (ICP-SFMS). Plutonium concentrations and 240Pu/239Pu atom ratios were generally consistent with previous terrestrial and marine studies in the region. The 239+240Pu levels (mBq kg−1, dry weight) ranged from 3.79 to 57.1 for lichen, 167–700 for kelp, 27.9–148 for horse mussel, and 560–573 for moss. Lichen from Adak Island had higher Pu concentrations than Amchitka Island, the difference was likely the result of the higher precipitation at Adak compared to Amchitka. The 240Pu/239Pu atom ratios were significantly higher in marine samples compared to terrestrial and freshwater samples (t-test, p 240Pu/239Pu ratios in terrestrial samples are within the range of global fallout. • Elevated 240Pu/239Pu in marine samples was characteristic of North Pacific Ocean. • Potential sources of enriched Pu to the marine environment regionally are suggested. • Pu ratios cannot by themselves explain the enriched Pu in seawater around Amchitka

  20. Accumulation of uranium by aquatic plants in field conditions: Prospects for phytoremediation

    International Nuclear Information System (INIS)

    A study was undertaken to determine Uranium concentrations in water and aquatic plants in the uraniferous region of Beiras, Central Portugal. Samples were collected from running water (n = 200) at places where aquatic species were observed. Plant samples were collected from 28 species of submerged, free-floating and rooted emergent plants including 2 bryophytes and 1 pteridophyte. Uranium concentrations in surface waters ranged from 0.23 to 1217 μg L−1. The aquatic plant species studied, including several previously untested species, exhibited the ability to accumulate U in concentrations many times that of the ambient water. In general submerged plants exhibited higher U content followed by rooted emergent and free floating species. The highest U concentrations were observed in the bryophyte Fontinalis antipyretica (up to 4979 mg kg−1) followed by Callitriche stagnalis (1963 mg kg−1), Callitriche hamulata (379 mg kg−1), Ranunculus peltatus subsp. saniculifolius (243 mg kg−1), Callitriche lusitanica (218 mg kg−1), and Ranunculus trichophyllus (65.8 mg kg−1). In two out of three rooted emergent species U seemed to be preferentially partitioned in rhizome/roots with highest rhizome U content recorded in Typha latifolia (380 mg kg−1). Among the free-floating species, the highest U content (42.5 mg kg−1) was seen in Lemna minor. The bryophyte F. antipyretica and Callitrichaceae members seem to be promising candidates for the development of phytofiltration methodologies based on U accumulation, abundance and biomass production. - Highlights: • Exploration of U contamination extent in uraniferous province of Central Portugal • A group of previously untested species with the ability to accumulate U was assessed • U accumulation patterns in the species indicate their potential in bioindication and phytoremediation of U-contaminated water

  1. Accumulation of uranium by aquatic plants in field conditions: Prospects for phytoremediation

    Energy Technology Data Exchange (ETDEWEB)

    Favas, Paulo J.C., E-mail: pjcf@utad.pt [School of Life Sciences and the Environment, University of Trás-os-Montes e Alto Douro, 5001-801 Vila Real (Portugal); IMAR-CMA Marine and Environmental Research Centre, Faculty of Sciences and Technology, University of Coimbra, 3001-401 Coimbra (Portugal); Pratas, João [Department of Earth Sciences, Faculty of Sciences and Technology, University of Coimbra, 3001-401 Coimbra (Portugal); IMAR-CMA Marine and Environmental Research Centre, Faculty of Sciences and Technology, University of Coimbra, 3001-401 Coimbra (Portugal); Varun, Mayank; D' Souza, Rohan; Paul, Manoj S. [Department of Botany, St. John' s College, Agra 282 002 (India)

    2014-02-01

    A study was undertaken to determine Uranium concentrations in water and aquatic plants in the uraniferous region of Beiras, Central Portugal. Samples were collected from running water (n = 200) at places where aquatic species were observed. Plant samples were collected from 28 species of submerged, free-floating and rooted emergent plants including 2 bryophytes and 1 pteridophyte. Uranium concentrations in surface waters ranged from 0.23 to 1217 μg L{sup −1}. The aquatic plant species studied, including several previously untested species, exhibited the ability to accumulate U in concentrations many times that of the ambient water. In general submerged plants exhibited higher U content followed by rooted emergent and free floating species. The highest U concentrations were observed in the bryophyte Fontinalis antipyretica (up to 4979 mg kg{sup −1}) followed by Callitriche stagnalis (1963 mg kg{sup −1}), Callitriche hamulata (379 mg kg{sup −1}), Ranunculus peltatus subsp. saniculifolius (243 mg kg{sup −1}), Callitriche lusitanica (218 mg kg{sup −1}), and Ranunculus trichophyllus (65.8 mg kg{sup −1}). In two out of three rooted emergent species U seemed to be preferentially partitioned in rhizome/roots with highest rhizome U content recorded in Typha latifolia (380 mg kg{sup −1}). Among the free-floating species, the highest U content (42.5 mg kg{sup −1}) was seen in Lemna minor. The bryophyte F. antipyretica and Callitrichaceae members seem to be promising candidates for the development of phytofiltration methodologies based on U accumulation, abundance and biomass production. - Highlights: • Exploration of U contamination extent in uraniferous province of Central Portugal • A group of previously untested species with the ability to accumulate U was assessed • U accumulation patterns in the species indicate their potential in bioindication and phytoremediation of U-contaminated water.

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

    Directory of Open Access Journals (Sweden)

    A. M. Snow

    2008-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Roland PSENNER

    2000-09-01

    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

  4. Protect and Restore the Upper Lochsa : Annual Progress Report, May 2008 – April 2009.

    Energy Technology Data Exchange (ETDEWEB)

    Lloyd, Rebecca; Forestieri, David [Nez Perce Tribe

    2009-08-13

    The Upper Lochsa watersheds included in the project contain critical spawning and rearing habitat for anadromous and resident fish (Clearwater National Forest 1999). Species that depend on the tributary habitat include spring chinook salmon (Oncorhynchus tshawytscha), Snake River summer steelhead (Oncorhynchus mykiss), bull trout (Salvelinus confluentes), and westslope cutthroat trout (Oncorhynchus clarki lewisi). Steelhead and bull trout populations are currently listed as Threatened under the Endangered Species Act (ESA), and westslope cutthroat trout has been petitioned for listing. Both out-of-basin and in-basin factors threaten fish populations in the Lochsa Drainage (Clearwater Subbasin Plan 2003). Out-of-basin factors include the hydroelectric system and ocean conditions, while in-basin factors include a variety of management activities leading to habitat degradation. This project is implemented under Bonneville Power Administration's Fish and Wildlife program in order to meet National Marine Fisheries Service requirements to offset losses caused by the operation of the hydrosystem by improving tributary habitats to promote increased productivity of salmon and steelhead. The Clearwater Subbasin Plan (2003) defines limiting factors to fisheries in the area as watershed disturbances, habitat degradation, sediment, temperature, and connectivity.

  5. Characterizing aquatic health using salmonid mortality, physiology, and biomass estimates in streams with elevated concentrations of arsenic, cadmium, copper, lead, and zinc in the Boulder River Watershed, Montana

    Science.gov (United States)

    Farag, A.M.; Skaar, D.; Nimick, D.A.; MacConnell, E.; Hogstrand, C.

    2003-01-01

    Abandoned tailings and mine adits are located throughout the Boulder River watershed in Montana. In this watershed, all species of fish are absent from some tributary reaches near mine sources: however, populations of brook trout Salvelinus fontitalis, rainbow trout Oncorhynchus mykiss, and cut-throat trout O. clarki are found further downstream. Multiple methods must be used to investigate the effects of metals released by past mining activity because the effects on aquatic life may range in severity, depending on the proximity of mine sources. Therefore, we used three types of effects - those on fish population levels (as measured by survival), those on biomass and density, and those at the level of the individual (as measured by increases in metallothionein, products of lipid peroxidation, and increases in concentrations of tissue metals) - to assess the aquatic health of the Boulder River watershed. Elevated concentrations of Cd, Cu, and Zn in the water column were associated with increased mortality of trout at sites located near mine waste sources. The hypertrophy (swelling), degeneration (dying), and necrosis of epithelial cells observed in the gills support our conclusion that the cause of death was related to metals in the water column. At a site further downstream (lower Cataract Creek), we observed impaired health of resident trout, as well as effects on biomass and density (measured as decreases in the kilograms of trout per hectare and the number per 300 m) and effects at the individual level, including increases in metallothionein, products of lipid peroxidation, and tissue concentrations of metals.

  6. Influences of body size and environmental factors on autumn downstream migration of bull trout in the Boise River, Idaho

    Science.gov (United States)

    Monnot, L.; Dunham, J.B.; Hoem, T.; Koetsier, P.

    2008-01-01

    Many fishes migrate extensively through stream networks, yet patterns are commonly described only in terms of the origin and destination of migration (e.g., between natal and feeding habitats). To better understand patterns of migration in bull trout,Salvelinus confluentus we studied the influences of body size (total length [TL]) and environmental factors (stream temperature and discharge) on migrations in the Boise River basin, Idaho. During the autumns of 2001-2003, we tracked the downstream migrations of 174 radio-tagged bull trout ranging in size from 21 to 73 cm TL. The results indicated that large bull trout (>30 cm) were more likely than small fish to migrate rapidly downstream after spawning in headwater streams in early autumn. Large bull trout also had a higher probability of arriving at the current terminus of migration in the system, Arrowrock Reservoir. The rate of migration by small bull trout was more variable and individuals were less likely to move into Arrowrock Reservoir. The rate of downstream migration by all fish was slower when stream discharge was greater. Temperature was not associated with the rate of migration. These findings indicate that fish size and environmentally related changes in behavior have important influences on patterns of migration. In a broader context, these results and other recent work suggest, at least in some cases, that commonly used classifications of migratory behavior may not accurately reflect the full range of behaviors and variability among individuals (or life stages) and environmental conditions. ?? Copyright by the American Fisheries Society 2008.

  7. Concentration and distribution of contaminants in lake trout and walleye from the Laurentian Great Lakes (2008-2012).

    Science.gov (United States)

    McGoldrick, Daryl J; Murphy, Elizabeth W

    2016-10-01

    Biomonitoring programs for persistent, bioaccumulative, and/or toxic chemicals of concern in fish tissues have been operated by the governments of Canada and the United States in the Great Lakes since the 1970's. The objectives of these programs are to assess concentrations of harmful chemicals in whole body top predator fish as an indicator of ecosystem health and to infer potential harm to fish and fish consuming wildlife in the Great Lakes Basin. Chemicals of interest are selected based upon national and binational commitments, risk assessment, and regulation, and include a wide range of compounds. This review summarizes all available data generated by Environment Canada and the United States Environmental Protection Agency for chemicals measured in whole body homogenates of Lake Trout (Salvelinus namaycush) and Walleye (Sander vitreus) for the time period spanning 2008 to 2012 from each of the five Great Lakes. The summary shows that concentrations of legacy compounds, such as, POPs listed in the Stockholm Convention and mercury continue to dominate the chemical burden of Great Lakes fish. This assessment, and others like it, can guide the creation of environmental quality targets where they are lacking, optimize chemical lists for monitoring, and prioritize chemicals of concern under agreements such as the Great Lakes Water Quality Agreement and the Stockholm Convention. PMID:26740246

  8. Are brown trout replacing or displacing bull trout populations in a changing climate?

    Science.gov (United States)

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

    2016-01-01

    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.

  9. Toxaphene in the aquatic environment of Greenland

    International Nuclear Information System (INIS)

    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. - Highlights: • Toxaphene was detected in freshwater and marine species of Greenland. • Relatively low concentrations in ringed seal suggest metabolisation. • The concentrations in Greenland appear lower than those in the Canadian Arctic. • Significant decreases were found in juvenile ringed seals and black guillemot eggs. - The banned insecticide toxaphene is widely present in the aquatic environment of Greenland, but concentrations are decreasing

  10. Toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during lake trout early life stage development

    International Nuclear Information System (INIS)

    The presence of halogenated aromatic hydrocarbons has been proposed to explain early life stage mortality seen in lake trout (Salvelinus namaycush) from the Great Lakes. Three years of experiments show that lake trout sac fry are extremely sensitive to TCDD. Newly fertilized lake trout eggs exposed to vehicle or graded water concentrations of 3H-TCDD for 48 hr accumulated 0, 40, 55, 60, 70, 110, 150, 170, 280, 370 or 530 ppt (pg 3H-TCDD/g egg). The 3H-TCDD persisted in the egg and sac fry stages (t1/2 = 349 days), but was rapidly eliminated in the fry stage (t1/2=40 days). Egg stage mortality was unaffected by TCDD (11%, mean); however, at the onset of hatching there was a dose-related increase in larvae dying half-hatched. The greatest dose-related mortality occurred in the sac fry stage and was associated with subcutaneous edema of the yolk sac membrane and hemorrhages, morphologically resembling blue-sac disease. Cumulative mortality at swim up was 19% (vehicle), 20-28% (40-60), 45% (70), 74% (110), and 100% (≥150 ppt 3H-TCDD). The LD50 in sac fry based on the 3H-TCDD egg burden was 75 ppt (71-77 ppt, 95% C.I.)

  11. Bathymetry, morphology, and lakebed geologic characteristics of potential Kokanee salmon spawning habitat in Lake Pend Oreille, Bayview and Lakeview quadrangles, Idaho

    Science.gov (United States)

    Barton, Gary J.; Dux, Andrew M.

    2013-01-01

    Kokanee salmon (Oncorhynchus nerka) are a keystone species in Lake Pend Oreille in northern Idaho, historically supporting a high-yield recreational fishery and serving as the primary prey for the threatened native bull trout (Salvelinus confluentus) and the Gerrard-strain rainbow trout (Oncorhynchus mykiss). After 1965, the kokanee population rapidly declined and has remained at a low level of abundance. Lake Pend Oreille is one of the deepest lakes in the United States, the largest lake in Idaho, and home to the U.S. Navy Acoustic Research Detachment Base. The U.S. Geological Survey and Idaho Department of Fish and Game are mapping the bathymetry, morphology, and the lakebed geologic units and embeddedness of potential kokanee salmon spawning habitat in Lake Pend Oreille. Relations between lake morphology, lakebed geologic units, and substrate embeddedness are characterized for the shore zone, rise zone, and open water in bays and the main stem of the lake. This detailed knowledge of physical habitat along the shoreline of Lake Pend Oreille is necessary to better evaluate and develop kokanee recovery actions.

  12. Egg fatty acid composition from lake trout fed two Lake Michigan prey fish species.

    Science.gov (United States)

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

    2009-01-01

    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.

  13. 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.

    2001-08-01

    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.

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

    Science.gov (United States)

    Rinella, D.J.; Wipfli, M.S.; Stricker, C.A.; Heintz, R.A.; Rinella, M.J.

    2012-01-01

    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.

  15. Trophic connections in Lake Superior Part II: the nearshore fish community

    Science.gov (United States)

    Gamble, A.E.; Hrabik, T.R.; Yule, D.L.; Stockwell, J.D.

    2011-01-01

    We use detailed diet analyses of the predominant planktivorous, benthivorous and piscivorous fish species from Lake Superior to create a nearshore (bathymetric depths Mysis diluviana and Diporeia spp). Although the piscivorous fishes like lean lake trout (Salvelinus namaycush) fed to a lesser extent on Diporeia and Mysis, they were still strongly connected to these macroinvertebrates, which were consumed by their primary prey species (sculpin spp., rainbow smelt Osmerus mordax, and coregonines). The addition of Bythotrephes to summer/fall cisco and lake whitefish diets, and the decrease in rainbow smelt in lean lake trout diets (replaced by coregonines) were the largest observed differences relative to historic Lake Superior diet studies. Although the offshore food web of Lake Superior was simpler than nearshore in terms of number of fish species present, the two areas had remarkably similar food web structures, and both fish communities were primarily supported by Mysis and Diporeia. We conclude that declines in Mysis or Diporeia populations would have a significant impact on energy flow in Lake Superior. The food web information we generated can be used to better identify management strategies for Lake Superior.

  16. Prey selection by the Lake Superior fish community

    Science.gov (United States)

    Isaac, Edmund J.; Hrabik, Thomas R.; Stockwell, Jason D.; Gamble, Allison E.

    2012-01-01

    Mysis diluviana is an important prey item to the Lake Superior fish community as found through a recent diet study. We further evaluated this by relating the quantity of prey found in fish diets to the quantity of prey available to fish, providing insight into feeding behavior and prey preferences. We describe the seasonal prey selection of major fish species collected across 18 stations in Lake Superior in spring, summer, and fall of 2005. Of the major nearshore fish species, bloater (Coregonus hoyi), rainbow smelt (Osmerus mordax), and lake whitefish (Coregonus clupeaformis) consumed Mysis, and strongly selected Mysis over other prey items each season. However, lake whitefish also selected Bythotrephes in the fall when Bythotrephes were numerous. Cisco (Coregonus artedi), a major nearshore and offshore species, fed largely on calanoid copepods, and selected calanoid copepods (spring) and Bythotrephes (summer and fall). Cisco also targeted prey similarly across bathymetric depths. Other major offshore fish species such as kiyi (Coregonus kiyi) and deepwater sculpin (Myoxocephalus thompsoni) fed largely on Mysis, with kiyi targeting Mysis exclusively while deepwater sculpin did not prefer any single prey organism. The major offshore predator siscowet lake trout (Salvelinus namaycush siscowet) consumed deepwater sculpin and coregonines, but selected deepwater sculpin and Mysis each season, with juveniles having a higher selection for Mysis than adults. Our results suggest that Mysis is not only a commonly consumed prey item, but a highly preferred prey item for pelagic, benthic, and piscivorous fishes in nearshore and offshore waters of Lake Superior.

  17. Trophic connections in Lake Superior Part I: the offshore fish community

    Science.gov (United States)

    Gamble, A.E.; Hrabik, T.R.; Stockwell, J.D.; Yule, D.L.

    2011-01-01

    Detailed diet linkages within the offshore (> 80 m bathymetric depth) food web of Lake Superior are currently not well identified. We used analyses of fish stomach contents to create an empirically based food web model of the Lake Superior offshore fish community. Stomachs were collected seasonally (spring, summer, and fall) from nine offshore locations in 2005, using bottom and midwater trawls. In total, 2643 stomachs representing 12 fish species were examined. The predominant fish species collected were deepwater sculpin (Myoxocephalus thompsonii), siscowet (Salvelinus namaycush siscowet), kiyi (Coregonus kiyi), and cisco (Coregonus artedi). Mysis diluviana was the most common prey item, indicating that changes in Mysis abundance could have a profound impact on the entire offshore food web. Mysis was the primary diet item of deepwater sculpin (≥ 53% by mass) and kiyi (≥ 96% by mass) regardless of depth or season. The invasive Bythotrephes was an important diet component of the pelagic cisco in summer and fall. Deepwater sculpin were the primary diet item of siscowet (≥ 52% by mass), with coregonines appearing in the diet of larger (> 400 mm) siscowet. Non-metric multidimensional scaling analysis indicated that there were no statistically significant seasonal or site-specific differences in diets of deepwater sculpin, cisco, or kiyi. Site was the primary structuring factor in siscowet diets. Generally, in Lake Superior, the diet items of the dominant offshore species did not appear to be in danger from those types of major ecological shifts occurring in the lower Laurentian Great Lakes.

  18. Accounting for adaptive capacity and uncertainty in assessments of species’ climate-change vulnerability

    Science.gov (United States)

    Wade, Alisa A.; Hand, Brian K.; Kovach, Ryan; Luikart, Gordon; Whited, Diane; Muhlfeld, Clint C.

    2016-01-01

    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.

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

    International Nuclear Information System (INIS)

    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

  20. Efficiency of portable antennas for detecting passive integrated transponder tags in stream-dwelling salmonids

    Science.gov (United States)

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

    2016-01-01

    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.

  1. Diet of lake trout and burbot in northern Lake Michigan during spring: Evidence of ecological interaction

    Science.gov (United States)

    Jacobs, Gregory R.; Madenjian, Charles P.; Bunnell, David B.; Holuszko, Jeffrey D.

    2010-01-01

    We used analyses of burbot (Lota lota) and lake trout (Salvelinus namaycush) diets taken during spring gill-net surveys in northern Lake Michigan in 2006-2008 to investigate the potential for competition and predator-prey interactions between these two species. We also compared our results to historical data from 1932. During 2006-2008, lake trout diet consisted mainly of alewives (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax), whereas burbot utilized a much wider prey base including round goby (Neogobius melanostomus), rainbow smelt, alewives, and sculpins. Using the Schoener's diet overlap index, we found a higher potential for interspecific competition in 1932 than in 2006-2008, though diet overlap was not significant in either time period. No evidence of cannibalism by lake trout or lake trout predation on burbot was found in either time period. In 2006-2008, however, lake trout composed 5.4% (by weight) of burbot diet. To determine whether this predation could be having an impact on lake trout rehabilitation efforts in northern Lake Michigan, we developed a bioenergetic-based consumption estimate for burbot on Boulder Reef (a representative reef within the Northern Refuge) and found that burbot alone can consume a considerable proportion of the yearling lake trout stocked annually, depending on burbot density. Overall, we conclude that predation, rather than competition, is the more important ecological interaction between burbot and lake trout, and burbot predation may be contributing to the failed lake trout rehabilitation efforts in Lake Michigan.

  2. Surficial substrates and bathymetry of five historical lake trout spawning reefs in near-shore waters of the Great Lakes

    Science.gov (United States)

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

    1992-01-01

    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.

  3. Side-scan sonar mapping of lake trout spawning habitat in northern Lake Michigan

    Science.gov (United States)

    Edsall, Thomas A.; Poe, Thomas P.; Nester, Robert T.; Brown, Charles L.

    1989-01-01

    Native stocks of lake trout Salvelinus namaycush were virtually or completely extirpated from the lower four Great Lakes by the early 1960s. The failure of early attempts to reestablish self-sustaining populations of lake trout was attributed partly to the practice of stocking hatcheryreared juveniles at locations and over substrates that had not been used in the past for spawning by native fish. Subsequent attempts to improve the selection of stocking locations were impeded by the lack of reliable information on the distribution of substrates on historical spawning grounds. Here we demonstrate the potential of side-scan sonar to substantially expand the data base needed to pinpoint the location of substrates where lake trout eggs, fry, or juveniles could be stocked to maximize survival and help ensure that survivors returning to spawn would encounter suitable substrates. We also describe the substrates and bathymetry of large areas on historical lake trout spawning grounds in the Fox Island Lake Trout Sanctuary in northern Lake Michigan. These areas could be used to support a contemporary self-sustaining lake trout population in the sanctuary and perhaps also in adjacent waters.

  4. Geochemical pathways and biological uptake of radium in small Canadian Shield lakes

    International Nuclear Information System (INIS)

    The sediment-water interactions and biological uptake of 226Ra are described for four small Canadian Shield lakes at the Experimental Lakes Area, Kenora, Ontario. A single addition of 226Ra was made to each lake between 1970 and 1976. Approximately 90 percent of the added 226Ra initially sorbed to the sediments. Outflow from the lakes showed losses of only 5-11 percent 226Ra per year. Models are proposed for adsorption and outflow of 226Ra from lakes. Biological uptake and long-term 226Ra concentrations were measured in three species of macrophytes, crayfish, and five species of fish. Bioaccumulation ranged from 1100 to 5000 in macrophytes, 705 in crayfish, from 30 to 80 in large trout (Salvelinus namaycush), white sucker (Catostomus commersoni), and lake whitefish (Coregonus clupeaformis), and from 230 to 1200 in fathead minnows (Pimephales promelas), pearl dace (Semotilus margarita), and northern redbelly dace (Chrosomus eos). The concept of Ra/Ca ratio in organisms versus water and food is used to explain the differences in bioaccumulation. 226Ra is discriminated against versus calcium by fish but favoured by macrophytes and crayfish

  5. Angler-caught piscivore diets reflect fish community changes in Lake Huron

    Science.gov (United States)

    Roseman, Edward F.; Schaeffer, Jeff; Bright, Ethan; Fielder, David G.

    2014-01-01

    Examination of angler-caught piscivore stomachs revealed that Lake Trout Salvelinus namaycush, Chinook Salmon Oncorhynchus tshawytscha, and Walleyes Sander vitreus altered theirdiets in response to unprecedented declines in Lake Huron's main-basin prey fish community.Diets varied by predator species, season, and location but were nearly always dominated numerically by some combination of Alewife Alosa pseudoharengus, Rainbow Smelt Osmerus mordax, Emerald Shiner Notropis atherinoides, Round Goby Neogobius melanostomus, or terrestrial insects. Rainbow Trout Oncorhynchus mykiss (steelhead), Coho Salmon Oncorhynchus kisutch, and Atlantic Salmon Salmo salar had varied diets that reflected higher contributions of insects. Compared with an earlier (1983–1986) examination of angler-caught predator fishes from Lake Huron, the contemporary results showed an increase in consumption of nontraditional prey (including conspecifics), use of smaller prey, and an increase in insects in the diet, suggesting that piscivores were faced with chronic prey limitation during this study. The management of all piscivores in Lake Huron will likely require consideration of the pervasive effects of changes in food webs, especially if prey fish remain at low levels.

  6. Effects of activity and energy budget balancing algorithm on laboratory performance of a fish bioenergetics model

    Science.gov (United States)

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

    2012-01-01

    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.

  7. Comparisons of likelihood and machine learning methods of individual classification

    Science.gov (United States)

    Guinand, B.; Topchy, A.; Page, K.S.; Burnham-Curtis, M. K.; Punch, W.F.; Scribner, K.T.

    2002-01-01

    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 (02.8% 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.

  8. Heritage strain and diet of wild young of year and yearling lake trout in the main basin of Lake Huron

    Science.gov (United States)

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

    2009-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Ronald; Kinkead, Bruce; Stanger, Mark

    2003-07-01

    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).

  10. Bull Trout Population Assessment in the White Salmon and Klickitat Rivers, Columbia River Gorge, Washington, 2001 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Thiesfeld, Steven L.; McPeak, Ronald H.; McNamara, Brian S. (Washington Department of Fish and Wildlife); Honanie, Isadore (Confederated Tribes and Bands, Yakama Nation)

    2002-01-01

    We utilized night snorkeling and single pass electroshocking to determine the presence or absence of bull trout Salvelinus confluentus in 26 stream reaches (3,415 m) in the White Salmon basin and in 71 stream reaches (9,005 m) in the Klickitat River basin during summer and fall 2001. We did not find any bull trout in the White Salmon River basin. In the Klickitat River basin, bull trout were found only in the West Fork Klickitat River drainage. We found bull trout in two streams not previously reported: Two Lakes Stream and an unnamed tributary to Fish Lake Stream (WRIA code number 30-0550). We attempted to capture downstream migrant bull trout in the West Fork Klickitat River by fishing a 1.5-m rotary screw trap at RM 4.3 from July 23 through October 17. Although we caught other salmonids, no bull trout were captured. The greatest limiting factor for bull trout in the West Fork Klickitat River is likely the small amount of available habitat resulting in a low total abundance, and the isolation of the population. Many of the streams are fragmented by natural falls, which are partial or complete barriers to upstream fish movement. To date, we have not been able to confirm that the occasional bull trout observed in the mainstem Klickitat River are migrating upstream into the West Fork Klickitat River.

  11. Visual sensitivity of deepwater fishes in Lake Superior.

    Directory of Open Access Journals (Sweden)

    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.

  12. Kalispell (i.e. Kalispel) Resident Fish Project : Annual Report, 1996.

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-08-01

    In 1996 the Kalispell Natural Resource Department (KNRD) in conjunction with the Washington Department of Fish and Wildlife (WDFW) continued the implementation of a habitat and population enhancement project for bull trout (Salvelinus confluentus), westslope cutthroat (Oncorhynchus clarki lewisi) and largemouth bass (Micropterus salmoides). A habitat and population assessment was conducted on Browns Creek a tributary of Cee Cee Ah Creek, one of the priority tributaries outlined in the 1995 annual report. The assessment was used to determine the type and quality of habitat that was limiting to native bull trout and cutthroat trout populations. Analysis of the habitat data indicated high amounts of sediment in the stream, low bank cover, and a lack of winter habitat. Data collected from this assessment was used to prescribe habitat enhancement measures for Browns Creek. Habitat enhancement measures, as outlined in the recommendations from the 1995 annual report, were conducted during field season 1996. Fencing and planting of riparian areas and in stream structures were implemented. As a precursor to these enhancement efforts, pre-assessments were conducted to determine the affects of the enhancement. Habitat quality, stream morphology and fish populations were pre-assessed. The construction of the largemouth bass hatchery was started in October of 1995. The KNRD, Contractors Northwest Inc. and associated subcontractors are in the process of constructing the hatchery. The projected date of hatchery completion is summer 1997.

  13. Causes of declining survival of lake trout stocked in U.S. waters of Lake Superior in 1963-1986

    Science.gov (United States)

    Hansen, Michael J.; Ebener, Mark P.; Schorfhaar, Richard G.; Schram, Stephen T.; Schreiner, Donald R.; Selgeby, James H.; Taylor, William W.

    1996-01-01

    Survival of the 1963-1982 year-classes of stocked yearling lake trout Salvelinus namaycush declined significantly over time in Lake Superior. To investigate possible causes of this decline, a Ricker model of stock-recruitment was used to describe the catch per effort (CPE) of age-7 stocked lake trout in the Michigan, Minnesota, and Wisconsin waters of Lake Superior as functions of the numbers of yearlings stocked 6 years earlier (an index of density dependence), the density (CPE) of wild adult lake trout (an index of predation), and large-mesh (a?Y 114-mm stretch-measure) gill-net fishing effort (an index of fishing mortality). Declining CPE of stocked lake trout in Michigan and Wisconsin was significantly associated with increasing large-mesh gillnet fishing effort. Declining CPE of stocked lake trout in Minnesota was significantly associated with increasing density of wild lake trout. Declining survival of stocked lake trout may therefore have been caused by increased mortality in large-mesh gill-net fisheries in Michigan and Wisconsin, and by predation by wild lake trout that recently recolonized the Minnesota area. We recommend that experimental management be pursued to determine the relative importance of large-mesh gillnet fishing effort and of predation by wild lake trout on the survival of stocked lake trout in U.S. waters of Lake Superior.

  14. The uranium in Kvanefjeld

    International Nuclear Information System (INIS)

    The report is a final thesis at the study of biology at the University of Copenhagen. It examines on a theoretical basis a number of possible environmental effects from a uranium mining and milling project under consideration at the Kvanefjeld site near Narssaq in South Greenland. An introductory description and discussion of the advantages and limitations of ecological baseline studies and dose committment assessments as a tool for planning and decision making is given. The leaching and atmospheric dispersion of particles, heavy metals, radionuclides and other elements from future waste rock and ore piles as well as from mill tailings at the Kvanefjeld site are analysed and discussed. Also, the mobility, transport and accumulation of potentially toxic elements in local terrestrial and aquatic ecosystems and food chains are examined. The resulting human burden are discussed with special attention given to the impact on the local population from eating lamb and seafood. A special quantitative analysis of the dispersion and biological uptake of fluoride, which is found in high concentrations in the ore, is given, focusing on the possible human intake of fluoride-polluted arctic char (Salvelinus alpinus) caught in Narrssaq River. The report at the end gives consideration to the long term problems of controlling mill tailings, discussing among other things the long term human exposure to radon and thoron daughters. (author)

  15. Denaturing gradient gel electrophoresis for nonlethal detection of Aeromonas salmonicida in salmonid mucus and its potential for other bacterial fish pathogens.

    Science.gov (United States)

    Quinn, Robert A; Stevenson, Roselynn M W

    2012-05-01

    Denaturing gradient gel electrophoresis (DGGE) of 16S rDNA was used to nonlethally detect Aeromonas salmonicida and other bacteria in salmonid skin mucus. Mucus samples from wild spawning coho salmon (Oncorhynchus kisutch) with endemic A. salmonicida and from cultured lake trout (Salvelinus namaycush) were tested by PCR-DGGE and were compared with mucus culture on Coomassie brilliant blue agar and internal organ culture. PCR-DGGE gave a highly reproducible 4-band pattern for 9 strains of typical A. salmonicida, which was different from other Aeromonas spp. Aeromonas salmonicida presence in mucus was evident as a band that comigrated with the bottom band of the A. salmonicida 4-band pattern and was verified by sequencing. PCR-DGGE found 36 of 52 coho salmon positive for A. salmonicida, compared with 31 positive by mucus culture and 16 by organ culture. Numerous other bacteria were detected in salmonid mucus, including Pseudomonas spp., Shewanella putrefaciens, Aeromonas hydrophila and other aeromonads. However, Yersinia ruckeri was not detected in mucus from 27 lake trout, but 1 fish had a sorbitol-positive Y. ruckeri isolated from organ culture. Yersinia ruckeri seeded into a mucus sample suggested that PCR-DGGE detection of this bacterium from mucus was possible. PCR-DGGE allows nonlethal detection of A. salmonicida in mucus and differentiation of some Aeromonas spp. and has the potential to allow simultaneous detection of other pathogens present in fish mucus. PMID:22506865

  16. Absence of fractionation of mercury isotopes during trophic transfer of methylmercury to freshwater fish in captivity

    Science.gov (United States)

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

    2012-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

    2003-08-01

    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.

  18. Acoustic estimates of abundance and distribution of spawning lake trout on Sheboygan Reef in Lake Michigan

    Science.gov (United States)

    Warner, D.M.; Claramunt, R.M.; Janssen, J.; Jude, D.J.; Wattrus, N.

    2009-01-01

    Efforts to restore self-sustaining lake trout (Salvelinus namaycush) populations in the Laurentian Great Lakes have had widespread success in Lake Superior; but in other Great Lakes, populations of lake trout are maintained by stocking. Recruitment bottlenecks may be present at a number of stages of the reproduction process. To study eggs and fry, it is necessary to identify spawning locations, which is difficult in deep water. Acoustic sampling can be used to rapidly locate aggregations of fish (like spawning lake trout), describe their distribution, and estimate their abundance. To assess these capabilities for application to lake trout, we conducted an acoustic survey covering 22 km2 at Sheboygan Reef, a deep reef (trout, that lake trout were 1–2 m above bottom, and that spawning took place over specific habitat. Lake trout density exhibited a high degree of spatial structure (autocorrelation) up to a range of ~190 m, and highest lake trout and egg densities occurred over rough substrates (rubble and cobble) at the shallowest depths sampled (36–42 m). Mean lake trout density in the area surveyed (~2190 ha) was 5.8 fish/ha and the area surveyed contained an estimated 9500–16,000 large lake trout. Spatial aggregation in lake trout densities, similarity of depths and substrates at which high lake trout and egg densities occurred, and relatively low uncertainty in the lake trout density estimate indicate that acoustic sampling can be a useful complement to other sampling tools used in lake trout restoration research.

  19. Assessing the feasibility of native fish reintroductions: a framework applied to threatened bull trout

    Science.gov (United States)

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

    2011-01-01

    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,

  20. Efficiency of Portable Antennas for Detecting Passive Integrated Transponder Tags in Stream-Dwelling Salmonids.

    Directory of Open Access Journals (Sweden)

    Nolan P Banish

    Full Text Available 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.

  1. Efficiency of Portable Antennas for Detecting Passive Integrated Transponder Tags in Stream-Dwelling Salmonids.

    Science.gov (United States)

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

    2016-01-01

    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. PMID:26901317

  2. A new approach toward evaluation of fish bioenergetics models

    Science.gov (United States)

    Madenjian, Charles P.; O'Connor, Daniel V.; Nortrup, David A.

    2000-01-01

    A new approach was used to evaluate the Wisconsin bioenergetics model for lake trout (Salvelinus namaycush). Lake trout in laboratory tanks were fed alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax), prey typical of lake trout in Lake Michigan. Food consumption and growth by lake trout during the experiment were measured. Polychlorinated biphenyl (PCB) concentrations of the alewife and rainbow smelt, as well as of the lake trout at the beginning and end of the experiment, were determined. From these data, we calculated that lake trout retained 81% of the PCBs contained within their food. In an earlier study, application of the Wisconsin lake trout bioenergetics model to growth and diet data for lake trout in Lake Michigan, in conjunction with PCB data for lake trout and prey fish from Lake Michigan, yielded an estimate of PCB assimilation efficiency from food of 81%. This close agreement in the estimates of efficiency with which lake trout retain PCBs from their food indicated that the bioenergetics model was furnishing accurate predictions of food consumption by lake trout in Lake Michigan.

  3. Reevaluation of lake trout and lake whitefish bioenergetics models

    Science.gov (United States)

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

    2013-01-01

    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.

  4. Preliminary evaluation of a lake whitefish (Coregonus clupeaformis) bioenergetics model

    Science.gov (United States)

    Madenjian, Charles P.; Pothoven, Steven A.; Schneeberger, Philip J.; O'Connor, Daniel V.; Brandt, Stephen B.

    2005-01-01

    We conducted a preliminary evaluation of a lake whitefish (Coregonus clupeaformis) bioenergetics model by applying the model to size-at-age data for lake whitefish from northern Lake Michigan. We then compared estimates of gross growth efficiency (GGE) from our bioenergetis model with previously published estimates of GGE for bloater (C. hoyi) in Lake Michigan and for lake whitefish in Quebec. According to our model, the GGE of Lake Michigan lake whitefish decreased from 0.075 to 0.02 as age increased from 2 to 5 years. In contrast, the GGE of lake whitefish in Quebec inland waters decreased from 0.12 to 0.05 for the same ages. When our swimming-speed submodel was replaced with a submodel that had been used for lake trout (Salvelinus namaycush) in Lake Michigan and an observed predator energy density for Lake Michigan lake whitefish was employed, our model predicted that the GGE of Lake Michigan lake whitefish decreased from 0.12 to 0.04 as age increased from 2 to 5 years.

  5. Use of rehabilitation experiments to understand the recovery dynamics of acid-stressed fish populations.

    Science.gov (United States)

    Snucins, Ed; Gunn, John M

    2003-04-01

    We used rehabilitation experiments involving the stocking of 2 native sportfish, lake trout (Salvelinus namaycush) and smallmouth bass (Micropterus dolomieu), in combination with recent fish community surveys, to study the recovery dynamics of fish populations in acid-stressed lakes near Sudbury and Killarney, Ontario, Canada. Population recovery rates differed between the 2 species. Introduced lake trout did poorly in species-rich lakes and exhibited slower growth, lower survival and delayed recruitment. Smallmouth bass, in contrast, readily colonized species-rich lakes. The biomass of natural smallmouth bass recruits increased to reference lake levels within 5 years following water quality recovery and spawning by stocked fish, whereas the biomass of natural lake trout recruits remained well below reference levels 5-15 years after water quality recovery and spawning by adults occurred. We document introductions by anglers of smallmouth bass into acid-damaged lake trout lakes, including some lakes that did not contain bass prior to acidification. This range expansion of a warm-water species (bass) that can alter food-web structure and reduce the growth of a cold-water species (trout), illustrates the potential for the combination of climate warming and species introductions to greatly alter the biological recovery endpoints in acid-stressed lakes. PMID:12839203

  6. Use of Rehabilitation Experiments to Understand the Recovery Dynamics of Acid-stressed Fish Populations

    Energy Technology Data Exchange (ETDEWEB)

    Snucins, Ed; Gunn, John M. [Laurentian Univ., Sudbury, ON (Canada). Dept. of Biology

    2003-04-01

    We used rehabilitation experiments involving the stocking of 2 native sportfish, lake trout (Salvelinus namaycush) and smallmouth bass (Micropterus dolomieu), in combination with recent fish community surveys, to study the recovery dynamics of fish populations in acid-stressed lakes near Sudbury and Killarney, Ontario, Canada. Population recovery rates differed between the 2 species. Introduced lake trout did poorly in species-rich lakes and exhibited slower growth, lower survival and delayed recruitment. Smallmouth bass, in contrast, readily colonized species-rich lakes. The biomass of natural smallmouth bass recruits increased to reference lake levels within 5 years following water quality recovery and spawning by stocked fish, whereas the biomass of natural lake trout recruits remained well below reference levels 5-15 years after water quality recovery and spawning by adults occurred. We document introductions by anglers of smallmouth bass into acid-damaged lake rout lakes, including some lakes that did not contain bass prior to acidification. This range expansion of a warm-water species (bass) that can alter food-web structure and reduce the growth of a cold water species (trout), illustrates the potential for the combination of climate warming and species introductions to greatly alter the biological recovery endpoints in acid-stressed lakes.

  7. Probabilistic accounting of uncertainty in forecasts of species distributions under climate change

    Science.gov (United States)

    Wenger, Seth J.; Som, Nicholas A.; Dauwalter, Daniel C.; Isaak, Daniel J.; Neville, Helen M.; Luce, Charles H.; Dunham, Jason B.; Young, Michael K.; Fausch, Kurt D.; Rieman, Bruce E.

    2013-01-01

    Forecasts of species distributions under future climates are inherently uncertain, but there have been few attempts to describe this uncertainty comprehensively in a probabilistic manner. We developed a Monte Carlo approach that accounts for uncertainty within generalized linear regression models (parameter uncertainty and residual error), uncertainty among competing models (model uncertainty), and uncertainty in future climate conditions (climate uncertainty) to produce site-specific frequency distributions of occurrence probabilities across a species’ range. We illustrated the method by forecasting suitable habitat for bull trout (Salvelinus confluentus) in the Interior Columbia River Basin, USA, under recent and projected 2040s and 2080s climate conditions. The 95% interval of total suitable habitat under recent conditions was estimated at 30.1–42.5 thousand km; this was predicted to decline to 0.5–7.9 thousand km by the 2080s. Projections for the 2080s showed that the great majority of stream segments would be unsuitable with high certainty, regardless of the climate data set or bull trout model employed. The largest contributor to uncertainty in total suitable habitat was climate uncertainty, followed by parameter uncertainty and model uncertainty. Our approach makes it possible to calculate a full distribution of possible outcomes for a species, and permits ready graphical display of uncertainty for individual locations and of total habitat.

  8. Chemical analysis of endolymph and the growing otolith: fractionation of metals in freshwater fish species.

    Science.gov (United States)

    Melancon, Sonia; Fryer, Brian J; Markham, James L

    2009-06-01

    The fractionation of metals from water to otolith is an area of research that has received relatively limited attention, especially in freshwater systems. The objectives of the present research were to study the metal partitioning between otolith and endolymph of two freshwater species: Lake trout (Salvelinus namaycush), and burbot (Lota lota). We also included the chemical analyses of water and blood from fish of the same species collected in the same area but during different years. These results provide insight regarding the partition of metals between water and fish. This is one of the first studies to provide a range of trace metal concentrations for endolymph and the growing otolith (both aragonite and vaterite) and to directly measure otolith-endolymph partition coefficients for freshwater fish. The trace elements (Mg, Sr, and Ba) most often used as otolith elemental tracers were the ones with the lowest uptake from water to blood. We found that endolymph and whole blood had similar metal concentrations, with Mg and Fe being the only elements enriched in whole blood. Results showed few significant differences in trace metal content between wild lake trout and burbot endolymph (except for K, Mg, and Ba), but significant differences existed between their aragonitic otoliths. These results suggest two different crystallization processes in these species or the presence of different proteins (and/or organic matrices) that would selectively influence elemental incorporation in the otoliths. PMID:19154085

  9. 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

    2002-12-01

    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).

  10. Projected climate-induced habitat loss for salmonids in the John Day River network, Oregon, U.S.A.

    Science.gov (United States)

    Ruesch, Aaron S.; Torgersen, Christian E.; Lawler, Joshua J.; Olden, Julian D.; Peterson, Erin E.; Volk, Carol J.; Lawrence, David J.

    2012-01-01

    Climate change will likely have profound effects on cold-water species of freshwater fishes. As temperatures rise, cold-water fish distributions may shift and contract in response. Predicting the effects of projected stream warming in stream networks is complicated by the generally poor correlation between water temperature and air temperature. Spatial dependencies in stream networks are complex because the geography of stream processes is governed by dimensions of flow direction and network structure. Therefore, forecasting climate-driven range shifts of stream biota has lagged behind similar terrestrial modeling efforts. We predicted climate-induced changes in summer thermal habitat for 3 cold-water fish species—juvenile Chinook salmon, rainbow trout, and bull trout (Oncorhynchus tshawytscha, O. mykiss, and Salvelinus confluentus, respectively)—in the John Day River basin, northwestern United States. We used a spatially explicit statistical model designed to predict water temperature in stream networks on the basis of flow and spatial connectivity. The spatial distribution of stream temperature extremes during summers from 1993 through 2009 was largely governed by solar radiation and interannual extremes of air temperature. For a moderate climate change scenario, estimated declines by 2100 in the volume of habitat for Chinook salmon, rainbow trout, and bull trout were 69–95%, 51–87%, and 86–100%, respectively. Although some restoration strategies may be able to offset these projected effects, such forecasts point to how and where restoration and management efforts might focus.

  11. Swimming endurance of bull trout, lake trout, arctic char, and rainbow trout following challenge with Renibacterium salmoninarum

    Science.gov (United States)

    Jones, D.T.; Moffitt, C.M.

    2004-01-01

    We tested the swimming endurance of juvenile bull trout Salvelinus confluentus, lake trout S. namaycush, Arctic char S. alpinus, and rainbow trout Oncorhynchus mykiss at 9??C and 15??C to determine whether sublethal infection from a moderate challenge of Renibacterium salmoninarum administered months before testing affected the length of time fish could maintain a swimming speed of 5-6 body lengths per second in an experimental flume. Rainbow trout and Arctic char swam longer in trials than did bull trout or lake trout, regardless of challenge treatment. When we tested fish 14-23 weeks postchallenge, we found no measurable effect of R. salmoninarum on the swimming endurance of the study species except for bull trout, which showed a mixed response. We conducted additional trials with bull trout 5-8 weeks postchallenge to determine whether increasing the challenge dose would affect swimming endurance and hematocrit. In those tests, bull trout with clinical signs of disease and those exposed to the highest challenge doses had significantly reduced swimming endurance compared with unchallenged control fish. Fish hematocrit levels measured at the end of all swimming endurance tests varied among species and between test temperatures, and patterns were not always consistent between challenged and control fish.

  12. Loss of genetic integrity in wild lake trout populations following stocking: insights from an exhaustive study of 72 lakes from Québec, Canada.

    Science.gov (United States)

    Valiquette, Eliane; Perrier, Charles; Thibault, Isabel; Bernatchez, Louis

    2014-06-01

    Stocking represents the most important management tool worldwide to increase and sustain commercial and recreational fisheries in a context of overexploitation. Genetic impacts of this practice have been investigated in many studies, which examined population and individual admixture, but few have investigated determinants of these processes. Here, we addressed these questions from the genotyping at 19 microsatellite loci of 3341 adult lake trout (Salvelinus namaycush) from 72 unstocked and stocked lakes. Results showed an increase in genetic diversity and a twofold decrease in the extent of genetic differentiation among stocked populations when compared to unstocked. Stocked populations were characterized by significant admixture at both population and individual levels. Moreover, levels of admixture in stocked populations were strongly correlated with stocking intensity and a threshold value of total homogenization between source and stocked populations was identified. Our results also suggest that under certain scenarios, the genetic impacts of stocking could be of short duration. Overall, our study emphasizes the important alteration of the genetic integrity of stocked populations and the need to better understand determinants of admixture to optimize stocking strategies and to conserve the genetic integrity of wild populations. PMID:25067947

  13. The effect of ether anesthesia on fin-clipping rate

    Science.gov (United States)

    Eschmeyer, Paul H.

    1953-01-01

    As part of an experimental program to learn the effects of stocking lake trout (Salvelinus namaycush) in Lake Superior, 141, 392 fingerlings were marked at the Charlevoix (Michigan) Station of the U.S. Fish and Wildlife Service in October 1952. The adipose fin was removed from all fish, the right pelvic from the remainder. A random sample of 2, 417 of the fish showed an average total length of 4.0 inches (range, 2.7 to 5.4). The mean weight of all fish marked was slightly less than one-third ounce (49 fish per pound). The local women, none of whom had previous experience in the work, were employed to mark the fish. Bone-cutting forceps were used for excision of the fins, and each worker wore a bobbinet glove to facilitate handling of the fish. On alternate days the fish were anesthetized with ether before marking, to determine the effect of its use on the fin-clipping rate.

  14. Empirical evaluation of predator-driven diel vertical migration in Lake Superior

    Science.gov (United States)

    Stockwell, J.D.; Hrabik, T.R.; Jensen, O.P.; Yule, D.L.; Balge, M.

    2010-01-01

    Recent studies on Lake Superior suggest that diel vertical migration (DVM) of prey (generalized Coregonus spp.) may be influenced by the density of predatory siscowet (Salvelinus namaycush). We empirically evaluated this hypothesis using data from acoustic, midwater trawl, and bottom trawl sampling at eight Lake Superior sites during three seasons in 2005 and a subset of sites in 2006. We expected the larger-bodied cisco (Coregonus artedi) to exhibit a shallower DVM compared with the smaller-bodied kiyi (Coregonus kiyi). Although DVM of kiyi and cisco were consistent with expectations of DVM as a size-dependent, predator-mediated process, we found no relationship between siscowet density and the magnitude of DVM of either coregonid. Cisco appear to have a size refuge from siscowet predation. Kiyi and siscowet co-occur in demersal habitat > 150 m during the day, where visual predation is unlikely, suggesting predator avoidance is not a factor in the daytime distribution of kiyi. Seasonal patterns of kiyi DVM were consistent with reported DVM of their primary prey Mysis relicta. Our results suggest that consideration of nonvisual foraging, rather than lightbased foraging theory (i.e., the antipredation window), is necessary to understand the processes driving DVM in deepwater systems.

  15. Revision of the American species of the genus Prionus Geoffroy, 1762 (Coleoptera, Cerambycidae, Prioninae, Prionini).

    Science.gov (United States)

    Santos-Silva, Antonio; Nearns, Eugenio H; Swift, Ian P

    2016-01-01

    A revision of the American species of Prionus Geoffroy, 1762 is presented. Prionus (Neopolyarthron) Semenov, 1899 and Prionus (Antennalia) Casey, 1912 are synonymized with Prionus Geoffroy, 1762. Homaesthesis LeConte, 1873 is considered a true subgenus of Prionus. Prionus (Homaesthesis) rhodocerus Linsley, 1957 and Prionus (Homaesthesis) linsleyi Hovore, 1981 are synonymized with Prionus simplex (Casey, 1912). Prionus beauvoisi Lameere, 1915 and Prionus (Neopolyarthron) debilis Casey, 1924 are synonymized with P. imbricornis (Linnaeus, 1767). Prionus (Neopolyarthron) townsendi Casey, 1912 and Prionus (Neopolyarthron) curticollis Casey, 1912 are synonymized with Prionus mexicanus Bates, 1884. Prionus batesi Lameere, 1920 is synonymized with Prionus aztecus Casey, 1912. Prionus hintoni Linsley, 1935 is synonymized with Prionus flohri Bates, 1884. Prionus (Antennalia) fissicornis parviceps Casey, 1912 is excluded as the synonym of Prionus fissicornis Haldeman, 1846 and instead synonymized with P. imbricornis (Linnaeus, 1767). Prionus (Prionus) validiceps Casey, 1912 is excluded from the synonymy of P. pocularis Dalman, 1817, and synonymized with P. (P.) californicus Motschulsky, 1845. Prionus (Prionus) tumidus Casey, 1912 is excluded from the synonymy of P. heroicus Semenov, 1907, and synonymized with P. (P.) californicus. The lectotype female and the paralectotype male of Prionus (Prionus) tristis are excluded from the synonym of P. (P.) heroicus and transferred to the synonym of P. (P.) californicus; the paralectotype female of P. (P.) tristis is maintained in the synonymy of P. (P.) heroicus. Prionus (Prionus) fontinalis Casey, 1914 is excluded from the synonymy of P. (P.) heroicus and synonymized with P. (P.) californicus. Prionus simplex is formally excluded from the Cerambycidae fauna of Oklahoma, USA. Comments on the page, plate, and figure of publication of Cerambyx laticollis Drury, 1773 are presented. Prionus (Trichoprionus) Fragoso & Monné, 1982 is

  16. Impact of thiamine deficiency on T-cell dependent and T-cell independent antibody production in lake trout

    Science.gov (United States)

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

    2012-01-01

    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.

  17. Climate change expands the spatial extent and duration of preferred thermal habitat for lake Superior fishes.

    Directory of Open Access Journals (Sweden)

    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.

  18. Wigwam River juvenile bull trout and fish habitat monitoring program: 2000 data report; TOPICAL

    International Nuclear Information System (INIS)

    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)

  19. Biotransformation of polychlorinated biphenyls (PCBs) and bioformation of hydroxylated PCBs in fish

    International Nuclear Information System (INIS)

    Hydroxylated PCBs (OH-PCBs) are a class of organic contaminants that have been found recently in the plasma of Great Lakes fish, the source of which is either bioformation from PCBs or accumulation from the environment. To address the potential for fish to biotransform PCBs and bioform OH-PCBs juvenile rainbow trout (Oncorhynchus mykiss; ∼80 g) were exposed to dietary concentrations of an environmentally relevant mixture of PCBs. Eight OH-PCBs were found in the plasma of rainbow trout after 30 days of exposure to the PCBs, the relative pattern of which was similar to those observed in wild lake trout (Salvelinus namaycush) from Lake Ontario. Hydroxylated-PCBs were not found (detection limit 0.02 pg/g) in the food or control (not PCB-exposed) fish. A curvilinear log t 1/2-log K ow relationship for recalcitrant PCBs was found, similar to previously reported relationships, although t 1/2 values were longer and shorter than studies using smaller fish or cooler temperatures, respectively. A number of PCB congeners fell below the log t 1/2-log K ow relationship providing the first estimates of non-chiral PCB biotransformation rates in fish. Enantioselective degradation of the chiral congeners PCBs 91 and 136, also indicated biotransformation. Biotransformation of PCBs was structure-dependent with greater biotransformation of PCBs with vicinal hydrogen atoms in the meta/para positions, suggesting CYP 2B-like biotransformation. Other chiral congeners with a meta/para substitution pattern showed no enantioselective degradation but were biotransformed based on the log t 1/2-log K ow relationship. The results of this study demonstrate that laboratory held rainbow trout can biotransform a number of PCB congeners and that bioformation is likely an important source of OH-PCBs in wild salmonids of the Great Lakes

  20. Malheur River Basin cooperative bull trout/redband trout research project, annual report FY 1999; ANNUAL

    International Nuclear Information System (INIS)

    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

  1. 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

    2009-04-09

    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.

  2. Warm acclimation and oxygen depletion induce species-specific responses in salmonids.

    Science.gov (United States)

    Anttila, Katja; Lewis, Mario; Prokkola, Jenni M; Kanerva, Mirella; Seppänen, Eila; Kolari, Irma; Nikinmaa, Mikko

    2015-05-15

    Anthropogenic activities are greatly altering the habitats of animals, whereby fish are already encountering several stressors simultaneously. The purpose of the current study was to investigate the capacity of fish to respond to two different environmental stressors (high temperature and overnight hypoxia) separately and together. We found that acclimation to increased temperature (from 7.7±0.02°C to 14.9±0.05°C) and overnight hypoxia (daily changes from normoxia to 63-67% oxygen saturation), simulating climate change and eutrophication, had both antagonistic and synergistic effects on the capacity of fish to tolerate these stressors. The thermal tolerance of Arctic char (Salvelinus alpinus) and landlocked salmon (Salmo salar m. sebago) increased with warm acclimation by 1.3 and 2.2°C, respectively, but decreased when warm temperature was combined with overnight hypoxia (by 0.2 and 0.4°C, respectively). In contrast, the combination of the stressors more than doubled hypoxia tolerance in salmon and also increased hypoxia tolerance in char by 22%. Salmon had 1.2°C higher thermal tolerance than char, but char tolerated much lower oxygen levels than salmon at a given temperature. The changes in hypoxia tolerance were connected to the responses of the oxygen supply and delivery system. The relative ventricle mass was higher in cold- than in warm-acclimated salmon but the thickness of the compact layer of the ventricle increased with the combination of warm and hypoxia acclimation in both species. Char had also significantly larger hearts and thicker compact layers than salmon. The results illustrate that while fish can have protective responses when encountering a single environmental stressor, the combination of stressors can have unexpected species-specific effects that will influence their survival capacity. PMID:25827840

  3. Tissue Phthalate Levels Correlate With Changes in Immune Gene Expression in a Population of Juvenile Wild Salmon.

    Science.gov (United States)

    Martins, Kelly; Hagedorn, Birgit; Ali, Shareen; Kennish, John; Applegate, Ben; Leu, Matthias; Epp, Lidia; Pallister, Chris; Zwollo, Patty

    2016-07-01

    Phthalates have detrimental effects on health and have been shown to dysregulate the immune system of mammals, birds, and fish. We recently reported that di(2-ethylhexyl) phthalate exposure reduces the abundance and inhibits the proliferation of rainbow trout (Oncorhynchus mykiss) IgM(+) B lymphocytes and expression of secreted immunoglobulin heavy-chain mu transcripts in an in vitro culture system. We proposed that phthalates act as immunomodulators by modifying the normal B cell-activation pathways by accelerating B cell differentiation while suppressing plasmablast expansion, thus resulting in fewer IgM-secreting plasma cells. This hypothesis was tested here in an in vivo field study of juvenile Dolly Varden (Salvelinus malma) from a plastic-polluted lake in the Gulf of Alaska. Fish tissues were analyzed for both phthalate levels using liquid chromatography-coupled tandem mass spectrometry and for changes in immune gene expression using reverse transcriptase-real time polymerase chain reaction. Results showed that fish with higher tissue levels of di(2-ethylhexyl) phthalate, di(n-butyl) phthalate, and/or dimethyl phthalate expressed significantly fewer secreted and membrane-bound immunoglobulin heavy-chain mu and Blimp1 transcripts in their hematopoietic tissue. This suggests that in vivo uptake of phthalates in fish changes the expression of B cell-specific genes. Chronic exposure to phthalates likely dysregulates normal B-lymphoid development and antibody responses in salmonids and may increase susceptibility to infection. Given the conserved nature of B-lineage cells in vertebrate animals, other marine species may be similarly affected by chronic phthalate exposure. PMID:27177745

  4. Bull Trout Life History, Genetics, Habitat Needs, and Limiting Factors in Central and Northeast Oregon, Annual Report 2000.

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-11-01

    This section describes work accomplished in 2000 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 continued to monitor the movements of bull trout with radio transmitters applied in 1998 (Hemmingsen, Bellerud, Gunckel and Howell 2001) and 1999 (Hemmingsen, Gunckel and Howell 2001). No new radio transmitters were applied to bull trout of the upper John Day River subbasin, Mill Creek (Walla Walla Basin), or the Grande Ronde Basin in 2000. We did implant radio transmitters in two bull trout incidentally captured in the John Day River near the confluence of the North Fork John Day River. In Mill Creek, we used traps to capture migrant bull trout to obtain data for the third successive year in this stream. With these traps, we intended to determine the timing of bull trout movements both upstream and downstream, and to determine the relative abundance, size and age of migrant fish. Because we captured migrant bull trout with traps for three years in the upper John Day River and its tributaries (Hemmingsen, Bellerud, Buchanan, Gunckel, Shappart and Howell 2001; Hemmingsen, Bellerud, Gunckel and Howell 2001; Hemmingsen, Gunckel and Howell 2001) and traps were no longer needed to capture bull trout for radio-tagging, no traps were operated in the John Day Basin in 2000.

  5. Host selection and lethality of attacks by sea lampreys (Petromyzon marinus) in laboratory studies

    Science.gov (United States)

    Swink, William D.

    2003-01-01

    Parasitic-phase sea lampreys (Petromyzon marinus) are difficult to study in the wild. A series of laboratory studies (1984-1995) of single attacks on lake trout (Salvelinus namaycush), rainbow trout (Oncorhynchus mykiss), and burbot (Lota lota) examined host size selection; determined the effects of host size, host species, host strain, and temperature on host mortality; and estimated the weight of hosts killed per lamprey. Rainbow trout were more able and burbot less able to survive attacks than lake trout. Small sea lampreys actively selected the larger of two small hosts; larger sea lampreys attacked larger hosts in proportion to the hosts' body sizes, but actively avoided shorter hosts (a?? 600 mm) when larger were available. Host mortality was significantly less for larger (43-44%) than for smaller hosts (64%). However, the yearly loss of hosts per sea lamprey was less for small hosts (range, 6.8-14.2 kg per sea lamprey) than larger hosts (range, 11.4-19.3 kg per sea lamprey). Attacks at the lower of two temperature ranges (6.1-11.8A?C and 11.1-15.0A?C) did not significantly reduce the percentage of hosts killed (54% vs. 69%, p > 0.21), but longer attachment times at lower temperatures reduced the number of hosts attacked (33 vs. 45), and produced the lowest loss of hosts (6.6 kg per sea lamprey). Low temperature appeared to offset other factors that increase host mortality. Reanalysis of 789 attacks pooled from these studies, using forward stepwise logistic regression, also identified mean daily temperature as the dominant factor affecting host mortality. Observations in Lakes Superior, Huron, and Ontario support most laboratory results.

  6. Feeding ecology of native and nonnative salmonids during the expansion of a nonnative apex predator in Yellowstone Lake, Yellowstone National Park

    Science.gov (United States)

    Syslo, John M.; Guy, Christopher S.; Koel, Todd M.

    2016-01-01

    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

  7. Trophic transfer of persistent organochlorine contaminants (OCs) within an Arctic marine food web from the southern Beaufort-Chukchi Seas

    Energy Technology Data Exchange (ETDEWEB)

    Hoekstra, P.F.; O' Hara, T.M.; Fisk, A.T.; Borgaa, K.; Solomon, K.R.; Muir, D.C.G

    2003-08-01

    The trophic status and biomagnification of persistent OCs within the near-shore Beaufort-Chukchi Seas food web from Barrow, AK is discussed. - Stable isotope values ({delta}{sup 13}C, {delta}{sup 15}N) and concentrations of persistent organochlorine contaminants (OCs) were determined to evaluate the near-shore marine trophic status of biota and biomagnification of OCs from the southern Beaufort-Chukchi Seas (1999-2000) near Barrow, AK. The biota examined included zooplankton (Calanus spp.), fish species such as arctic cod (Boreogadus saida), arctic char (Salvelinus alpinus), pink salmon (Oncorhynchus gorbuscha), and fourhorn sculpin (Myoxocephalus quadricornis), along with marine mammals, including bowhead whales (Balaena mysticetus), beluga whales (Delphinapterus leucas), ringed seals (Phoca hispida) and bearded seals (Erignathus barbatus). The isotopically derived trophic position of biota from the Beaufort-Chukchi Seas marine food web, avian fauna excluded, is similar to other coastal food webs in the Arctic. Concentrations of OCs in marine mammals were significantly greater than in fish and corresponded with determined trophic level. In general, OCs with the greatest food web magnification factors (FWMFs) were those either formed due to biotransformation (e.g. p,p'-DDE, oxychlordane) or considered recalcitrant (e.g. {beta}-HCH, 2,4,5-Cl substituted PCBs) in most biota, whereas concentrations of OCs that are considered to be readily eliminated (e.g. {gamma}-HCH) did not correlate with trophic level. Differences in physical-chemical properties of OCs, feeding strategy and possible biotransformation were reflected in the variable biomagnification between fish and marine mammals. The FWMFs in the Beaufort-Chukchi Seas region were consistent with reported values in the Canadian Arctic and temperate food webs, but were statistically different than FWMFs from the Barents and White Seas, indicating that the spatial variability of OC contamination in top

  8. Direct and indirect responses of a freshwater food web to a potent synthetic oestrogen

    Science.gov (United States)

    Kidd, Karen A.; Paterson, Michael J.; Rennie, Michael D.; Podemski, Cheryl L.; Findlay, Dave L.; Blanchfield, Paul J.; Liber, Karsten

    2014-01-01

    Endocrine-disrupting chemicals (EDCs) in municipal effluents directly affect the sexual development and reproductive success of fishes, but indirect effects on invertebrate prey or fish predators through reduced predation or prey availability, respectively, are unknown. At the Experimental Lakes Area in northwestern Ontario, Canada, a long-term, whole-lake experiment was conducted using a before-after-control-impact design to determine both direct and indirect effects of the synthetic oestrogen used in the birth control pill, 17α-ethynyloestradiol (EE2). Algal, microbial, zooplankton and benthic invertebrate communities showed no declines in abundance during three summers of EE2 additions (5–6 ng l−1), indicating no direct toxic effects. Recruitment of fathead minnow (Pimephales promelas) failed, leading to a near-extirpation of this species both 2 years during (young-of-year, YOY) and 2 years following (adults and YOY) EE2 additions. Body condition of male lake trout (Salvelinus namaycush) and male and female white sucker (Catostomus commersonii) declined before changes in prey abundance, suggesting direct effects of EE2 on this endpoint. Evidence of indirect effects of EE2 was also observed. Increases in zooplankton, Chaoborus, and emerging insects were observed after 2 or 3 years of EE2 additions, strongly suggesting indirect effects mediated through the reduced abundance of several small-bodied fishes. Biomass of top predator lake trout declined by 23–42% during and after EE2 additions, most probably an indirect effect from the loss of its prey species, the fathead minnow and slimy sculpin (Cottus cognatus). Our results demonstrate that small-scale studies focusing solely on direct effects are likely to underestimate the true environmental impacts of oestrogens in municipal wastewaters and provide further evidence of the value of whole-ecosystem experiments for understanding indirect effects of EDCs and other aquatic stressors. PMID:25405967

  9. Drying temperature effects on fish dry mass measurements

    Science.gov (United States)

    Lantry, B.F.; O'Gorman, R.

    2007-01-01

    Analysis of tissue composition in fish often requires dry samples. Time needed to dry fish decreases as temperature is increased, but additional volatile material may be lost. Effects of 10??C temperature increases on percentage dry mass (%DM) were tested against 60??C controls for groups of lake trout Salvelinus namaycush, rainbow smelt Osmerus mordax, slimy sculpin Cottus cognatus, and alewife Alosa pseudoharengus. Lake trout %DMs were lower at greater temperatures, but not significantly different from 60??C controls. Rainbow smelt and slimy sculpin %DMs were lower at greater temperatures and differences were significant when test temperatures reached 90??C. Significant differences were not found in tests using alewives because variability in %DM was high between fish. To avoid inter-fish variability, 30 alewives were each dried successively at 60, 70, 80, and then 90??C and for all fish %DM declined at each higher temperature. In general, %DMs were lower at greater temperatures and after reaching a stable dry weight, fish did not lose additional mass if temperature remained constant. Results indicate that caution should be used when comparing dry mass related indices from fish dried at different temperatures because %DM was negatively related to temperature. The differences in %DM observed with rising temperature could account for substantial portions of the variability in reported energy values for the species tested. Differences in %DM means for the 60 vs. 80??C and 60 vs. 90??C tests for rainbow smelt and alewife could represent of from 8 to 38% of observed annual energy cycles for Lakes Ontario and Michigan.

  10. Maternal characteristics versus egg size and energy density: do stocked lake trout in Lake Ontario experience premature reproductive senescence?

    Science.gov (United States)

    Lantry, B.F.; O'Gorman, R.; Machut, L.S.

    2008-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Heggenes Jan

    2011-07-01

    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

  12. Kootenai River fisheries investigations: rainbow and bull trout recruitment: annual progress report 1999; ANNUAL

    International Nuclear Information System (INIS)

    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

  13. Comparison of three nonlinear models to describe long-term tag shedding by lake trout

    Science.gov (United States)

    Fabrizio, Mary C.; Swanson, Bruce L.; Schram, Stephen T.; Hoff, Michael H.

    1996-01-01

    We estimated long-term tag-shedding rates for lake trout Salvelinus namaycush using two existing models and a model we developed to account for the observed permanence of some tags. Because tag design changed over the course of the study, we examined tag-shedding rates for three types of numbered anchor tags (Floy tags FD-67, FD-67C, and FD-68BC) and an unprinted anchor tag (FD-67F). Lake trout from the Gull Island Shoal region, Lake Superior, were double-tagged, and subsequent recaptures were monitored in annual surveys conducted from 1974 to 1992. We modeled tag-shedding rates, using time at liberty and probabilities of tag shedding estimated from fish released in 1974 and 1978–1983 and later recaptured. Long-term shedding of numbered anchor tags in lake trout was best described by a nonlinear model with two parameters: an instantaneous tag-shedding rate and a constant representing the proportion of tags that were never shed. Although our estimates of annual shedding rates varied with tag type (0.300 for FD-67, 0.441 for FD-67C, and 0.656 for FD-68BC), differences were not significant. About 36% of tags remained permanently affixed to the fish. Of the numbered tags that were shed (about 64%), two mechanisms contributed to tag loss: disintegration and dislodgment. Tags from about 11% of recaptured fish had disintegrated, but most tags were dislodged. Unprinted tags were shed at a significant but low rate immediately after release, but the long-term, annual shedding rate of these tags was only 0.013. Compared with unprinted tags, numbered tags dislodged at higher annual rates; we hypothesized that this was due to the greater frictional drag associated with the larger cross-sectional area of numbered tags.

  14. Kootenai River Fisheries Investigations; Rainbow and Bull Trout Recruitment, 1999 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Walters, Jody P.; Downs, Christopher C.

    2001-08-01

    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.

  15. Trophic transfer of persistent organochlorine contaminants (OCs) within an Arctic marine food web from the southern Beaufort-Chukchi Seas

    International Nuclear Information System (INIS)

    The trophic status and biomagnification of persistent OCs within the near-shore Beaufort-Chukchi Seas food web from Barrow, AK is discussed. - Stable isotope values (δ13C, δ15N) and concentrations of persistent organochlorine contaminants (OCs) were determined to evaluate the near-shore marine trophic status of biota and biomagnification of OCs from the southern Beaufort-Chukchi Seas (1999-2000) near Barrow, AK. The biota examined included zooplankton (Calanus spp.), fish species such as arctic cod (Boreogadus saida), arctic char (Salvelinus alpinus), pink salmon (Oncorhynchus gorbuscha), and fourhorn sculpin (Myoxocephalus quadricornis), along with marine mammals, including bowhead whales (Balaena mysticetus), beluga whales (Delphinapterus leucas), ringed seals (Phoca hispida) and bearded seals (Erignathus barbatus). The isotopically derived trophic position of biota from the Beaufort-Chukchi Seas marine food web, avian fauna excluded, is similar to other coastal food webs in the Arctic. Concentrations of OCs in marine mammals were significantly greater than in fish and corresponded with determined trophic level. In general, OCs with the greatest food web magnification factors (FWMFs) were those either formed due to biotransformation (e.g. p,p'-DDE, oxychlordane) or considered recalcitrant (e.g. β-HCH, 2,4,5-Cl substituted PCBs) in most biota, whereas concentrations of OCs that are considered to be readily eliminated (e.g. γ-HCH) did not correlate with trophic level. Differences in physical-chemical properties of OCs, feeding strategy and possible biotransformation were reflected in the variable biomagnification between fish and marine mammals. The FWMFs in the Beaufort-Chukchi Seas region were consistent with reported values in the Canadian Arctic and temperate food webs, but were statistically different than FWMFs from the Barents and White Seas, indicating that the spatial variability of OC contamination in top-level marine Arctic predators is attributed to

  16. 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

    1996-03-01

    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.

  17. Quantitative polymerase chain reaction (PCR) assays for a bacterial thiaminase I gene and the thiaminase-producing bacterium Paenibacillus thiaminolyticus.

    Science.gov (United States)

    Richter, C.A.; Wright-Osment, Maureen K.; Zajicek, J.L.; Honeyfield, D.C.; Tillitt, D.E.

    2009-01-01

    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.

  18. Egg thiamine status of Lake Ontario salmonines 1995-2004 with emphasis on lake trout

    Science.gov (United States)

    Fitzsimons, J.D.; Williston, B.; Williston, G.; Brown, L.; El-Shaarawi, A.; Vandenbyllaardt, L.; Honeyfeld, D.; Tillitt, D.; Wolgamood, M.; Brown, S.B.

    2007-01-01

    Alewives (Alosa pseudoharengus), the major prey fish for Lake Ontario, contain thiaminase. They are associated with development of a thiamine deficiency in salmonines which greatly increases the potential for developing an early mortality syndrome (EMS). To assess the possible effects of thiamine deficiency on salmonine reproduction we measured egg thiamine concentrations for five species of Lake Ontario salmonines. From this we estimated the proportion of families susceptible to EMS based on whether they were below the ED20, the egg thiamine concentration associated with 20% mortality due to EMS. The ED20s were 1.52, 2.63, and 2.99 nmol/g egg for Chinook salmon (Oncorhynchus tshawytscha), lake trout (Salvelinus namaycush), and coho salmon (Oncorhynchus kisutch), respectively. Based on the proportion of fish having egg thiamine concentrations falling below the ED20, the risk of developing EMS in Lake Ontario was highest for lake trout, followed by coho (O. kisutch), and Chinook salmon, with the least risk for rainbow trout (O. mykiss). For lake trout from western Lake Ontario, mean egg thiamine concentration showed significant annual variability during 1994 to 2003, when the proportion of lake trout at risk of developing EMS based on ED20 ranged between 77 and 100%. Variation in the annual mean egg thiamine concentration for western Lake Ontario lake trout was positively related (p < 0.001, r2 = 0.94) with indices of annual adult alewife biomass. While suggesting the possible involvement of density-dependent changes in alewives, the changes are small relative to egg thiamine concentrations when alewife are not part of the diet and are of insufficient magnitude to allow for natural reproduction by lake trout.

  19. Evaluation of offshore stocking of Lake Trout in Lake Ontario

    Science.gov (United States)

    Lantry, B.F.; O'Gorman, R.; Strang, T.G.; Lantry, J.R.; Connerton, M.J.; Schanger, T.

    2011-01-01

    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

  20. Developing recreational harvest regulations for an unexploited lake trout population

    Science.gov (United States)

    Lenker, Melissa A; Weidel, Brian C.; Jensen, Olaf P.; Solomon, Christopher T.

    2016-01-01

    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.

  1. Use of a seismic air gun to reduce survival of nonnative lake trout embryos: A tool for conservation?

    Science.gov (United States)

    Cox, B.S.; Dux, A.M.; Quist, M.C.; Guy, C.S.

    2012-01-01

    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.

  2. Long-term impacts of invasive species on a native top predator in a large lake system

    Science.gov (United States)

    Rush, Scott A.; Paterson, Gordon; Johnson, Tim B.; Drouillard, Ken G.; Haffner, Gordon D.; Hebert, Craig E.; Arts, Michael T.; McGoldrick, Daryl J.; Backus, Sean M.; Lantry, Brian F.; Lantry, Jana R.; Schaner, Ted; Fisk, Aaron T.

    2012-01-01

    1. Declining abundances of forage fish and the introduction and establishment of non-indigenous species have the potential to substantially alter resource and habitat exploitation by top predators in large lakes. 2. We measured stable isotopes of carbon (δ13C) and nitrogen (δ15N) in field-collected and archived samples of Lake Ontario lake trout (Salvelinus namaycush) and five species of prey fish and compared current trophic relationships of this top predator with historical samples. 3. Relationships between δ15N and lake trout age were temporally consistent throughout Lake Ontario and confirmed the role of lake trout as a top predator in this food web. However, δ13C values for age classes of lake trout collected in 2008 ranged from 1.0 to 3.9‰ higher than those reported for the population sampled in 1992. 4. Isotope mixing models predicted that these changes in resource assimilation were owing to the replacement of rainbow smelt (Osmerus mordax) by round goby (Neogobius melanostomus) in lake trout diet and increased reliance on carbon resources derived from nearshore production. This contrasts with the historical situation in Lake Ontario where δ13C values of the lake trout population were dominated by a reliance on offshore carbon production. 5. These results indicate a reduced capacity of the Lake Ontario offshore food web to support the energetic requirements of lake trout and that this top predator has become increasingly reliant on prey resources that are derived from nearshore carbon pathways.

  3. Vateritic sagitta in wild and stocked lake trout: Applicability to stock origin

    Science.gov (United States)

    Bowen, Charles A., II; Bronte, Charles R.; Argyle, Ray L.; Adams, Jean V.; Johnson, James E.

    1999-01-01

    Aragonite is the normal form of calcium carbonate found in teleost otoliths, but it is sometimes replaced by vaterite, an alternate crystalline structure. We investigated the assumption that sagittal otoliths with vaterite replacement were unique to stocked lake trout Salvelinus namaycush in the Laurentian Great Lakes. Earlier studies had attributed these abnormalities to stocking stress, and proposed that the presence of vaterite could separate individual unmarked stocked lake trout from their wild counterparts. We examined and described the frequency of vateritic sagittae in two wild and three stocked populations of lake trout from the Great Lakes and a wild population from a remote inland lake in northern Canada. Among lake trout caught 2–12 years after being stocked, prevalence of vateritic sagittae was 66% for Lake Superior fish, 75% for Lake Huron fish, and 86% for Lake Ontario fish. Among wild fish caught, vateritic sagittae were present in 37% of Lake Superior fish, 22% of Lake Huron fish, and 49% of northern Canada fish. We also compared year-to-year differences in prevalence in four year-classes of fingerling lake trout reared in two U.S. national lake trout hatcheries. Prior to release, between 53 and 84% of the hatchery fish had at least one vateritic sagitta, and prevalence increased with handling associated with hatchery practices. Vateritic sagittae in wild fish might also indicate stress in nature. The presence of vateritic sagittae in both wild and stocked fish compromises the use of this characteristic as an unequivocal indicator of a particular fish's origin. Among-population differences in both the prevalence and the extent of vaterite replacement, however, may provide a means of differentiating between stocks of sympatric unmarked wild and stocked lake trout.

  4. Bathythermal habitat use by strains of Great Lakes- and Finger Lakes-origin lake trout in Lake Huron after a change in prey fish abundance and composition

    Science.gov (United States)

    Bergstedt, Roger A.; Argyle, Ray L.; Krueger, Charles C.; Taylor, William W.

    2012-01-01

    A study conducted in Lake Huron during October 1998–June 2001 found that strains of Great Lakes-origin (GLO) lake trout Salvelinus namaycush occupied significantly higher temperatures than did Finger Lakes-origin (FLO; New York) lake trout based on data from archival (or data storage) telemetry tags that recorded only temperature. During 2002 and 2003, we implanted archival tags that recorded depth as well as temperature in GLO and FLO lake trout in Lake Huron. Data subsequently recorded by those tags spanned 2002–2005. Based on those data, we examined whether temperatures and depths occupied by GLO and FLO lake trout differed during 2002–2005. Temperatures occupied during those years were also compared with occupied temperatures reported for 1998–2001, before a substantial decline in prey fish biomass. Temperatures occupied by GLO lake trout were again significantly higher than those occupied by FLO lake trout. This result supports the conclusion of the previous study. The GLO lake trout also occupied significantly shallower depths than FLO lake trout. In 2002–2005, both GLO and FLO lake trout occupied significantly lower temperatures than they did in 1998–2001. Aside from the sharp decline in prey fish biomass between study periods, the formerly abundant pelagic alewife Alosa pseudoharengus virtually disappeared and the demersal round goby Neogobius melanostomus invaded the lake and became locally abundant. The lower temperatures occupied by lake trout in Lake Huron during 2002–2005 may be attributable to changes in the composition of the prey fish community, food scarcity (i.e., a retreat to cooler water could increase conversion efficiency), or both.

  5. A riverscape perspective of Pacific salmonids and aquatic habitats prior to large-scale dam removal in the Elwha River, Washington, USA

    Science.gov (United States)

    Brenkman, S.J.; Duda, J.J.; Torgersen, C.E.; Welty, E.; Pess, G.R.; Peters, R.; McHenry, M.L.

    2012-01-01

     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.

  6. Combining demographic and genetic factors to assess population vulnerability in stream species

    Science.gov (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

    2014-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Henrik Kylin

    2015-10-01

    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.

  8. Umatilla Basin natural production monitoring and evaluation. Annual progress report, 1994--1995

    International Nuclear Information System (INIS)

    This report summarizes the activities of the Umatilla Basin Natural Production Monitoring and Evaluation Project (UBNPME) from September 30, 1994 to September 29, 1995. This program was funded by Bonneville Power Administration and was managed under the Fisheries Program, Department of Natural Resources, Confederated Tribes of the Umatilla Indian Reservation. An estimated 36.7 km (22.6 miles) of stream habitat were inventoried on the Umatilla River, Moonshine, Mission, Cottonwood and Coonskin Creeks. A total of 384 of 3,652 (10.5%) habitat units were electrofished. The number of juvenile fish captured follows: 2,953 natural summer steelhead (including resident rainbow trout; Oncorhynchus mykiss), one hatchery steelhead, 341 natural chinook salmon (O. tshawytscha), 163 natural coho salmon (O. kisutch), five bull trout (Salvelinus confluentus), 185 mountain whitefish (Prosopium williamsoni), and six northern squawfish (Ptychoicheilus oregonensis). The expanded population estimate for the areas surveyed was 73,716 salmonids with a mean density of 0.38 fish/m2. Relative salmonid abundance, seasonal distribution and habitat utilization were monitored at index sites throughout the basin. During index site monitoring, the following species were collected in addition to those listed above: american shad (Alosa sapidissima), smallmouth bass (Micropterus dolomieu), carp (Cyprinus carpio) and chiselmouth (Acrocheilus alutaceus). Thirty-nine sites were electrofished during the spring and summer seasons, while 36 sites were sampled in the fall season. A study of the migration movements and homing requirements of adult salmonids in the Umatilla River was conducted during the 1994-95 return years. Radio telemetry was used to evaluate the movements of adult salmonids past diversion dams in the lower Umatilla River and to determine migrational movements of salmonids following upstream transport

  9. A Quantitative Polymerase Chain Reaction Assay for the Detection and Quantification of Epizootic Epitheliotropic Disease Virus (EEDV; Salmonid Herpesvirus 3).

    Science.gov (United States)

    Glenney, Gavin W; Barbash, Patricia A; Coll, John A

    2016-03-01

    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. PMID:26980561

  10. The Microbiota of Freshwater Fish and Freshwater Niches Contain Omega-3 Fatty Acid-Producing Shewanella Species.

    Science.gov (United States)

    Dailey, Frank E; McGraw, Joseph E; Jensen, Brittany J; Bishop, Sydney S; Lokken, James P; Dorff, Kellen J; Ripley, Michael P; Munro, James B

    2016-01-01

    Approximately 30 years ago, it was discovered that free-living bacteria isolated from cold ocean depths could produce polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) (20:5n-3) or docosahexaenoic acid (DHA) (22:6n-3), two PUFA essential for human health. Numerous laboratories have also discovered that EPA- and/or DHA-producing bacteria, many of them members of the Shewanella genus, could be isolated from the intestinal tracts of omega-3 fatty acid-rich marine fish. If bacteria contribute omega-3 fatty acids to the host fish in general or if they assist some bacterial species in adaptation to cold, then cold freshwater fish or habitats should also harbor these producers. Thus, we undertook a study to see if these niches also contained omega-3 fatty acid producers. We were successful in isolating and characterizing unique EPA-producing strains of Shewanella from three strictly freshwater native fish species, i.e., lake whitefish (Coregonus clupeaformis), lean lake trout (Salvelinus namaycush), and walleye (Sander vitreus), and from two other freshwater nonnative fish, i.e., coho salmon (Oncorhynchus kisutch) and seeforellen brown trout (Salmo trutta). We were also able to isolate four unique free-living strains of EPA-producing Shewanella from freshwater habitats. Phylogenetic and phenotypic analyses suggest that one producer is clearly a member of the Shewanella morhuae species and another is sister to members of the marine PUFA-producing Shewanella baltica species. However, the remaining isolates have more ambiguous relationships, sharing a common ancestor with non-PUFA-producing Shewanella putrefaciens isolates rather than marine S. baltica isolates despite having a phenotype more consistent with S. baltica strains. PMID:26497452

  11. Spatial and temporal trends of mercury and other metals in landlocked char from lakes in the Canadian Arctic archipelago

    International Nuclear Information System (INIS)

    Spatial and temporal trends of mercury (Hg) and 22 other elements were examined in landlocked Arctic char (Salvelinus alpinus) from six lakes in the Canadian Arctic (Char, Resolute and North Lakes, and Amituk Lake on Cornwallis Island, Sapphire Lake on Devon Island and Boomerang Lake on Somerset Island). The objectives of the study were to compare recent concentrations of Hg and other metals in char with older data from Amituk, Resolute and Char Lakes, in order to examine temporal trends as well as to investigate factors influencing spatial trends in contaminant levels such as lake characteristics, trophic position, size and age of the fish. Geometric mean Hg concentrations in dorsal muscle ranged from 0.147 μg/g wet weight (ww) in Resolute Lake to 1.52 μg/g ww in Amituk Lake for samples collected over the period 1999-2003. Char from Amituk Lake also had significantly higher selenium (Se). Mercury in char from Resolute Lake was strongly correlated with fish length, weight, and age, as well as with thallium, lead and Se. In 5 of 6 lakes, Hg concentrations were correlated with stable nitrogen isotope ratios (δ 15N) and larger char were feeding at a higher trophic level presumably due to feeding on smaller char. Weight adjusted mean Hg concentrations in char from Amituk Lake, and unadjusted geometric means in Char Lake and Resolute Lakes, did not show any statistically significant increase from the early 1990s to 2003. However, small sample sizes from 1999-2003 for fish 15N values best explained the higher concentrations of Hg in Amituk Lake compared to the other lakes

  12. Sample size requirements and analysis of tag recoveries for paired releases of lake trout

    Science.gov (United States)

    Elrod, Joseph H.; Frank, Anthony

    1990-01-01

    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.

  13. Bull trout life history, genetics, habitat needs, and limiting fact in central and northeast Oregon, annual report 2000.; ANNUAL

    International Nuclear Information System (INIS)

    This section describes work accomplished in 2000 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 continued to monitor the movements of bull trout with radio transmitters applied in 1998 (Hemmingsen, Bellerud, Gunckel and Howell 2001) and 1999 (Hemmingsen, Gunckel and Howell 2001). No new radio transmitters were applied to bull trout of the upper John Day River subbasin, Mill Creek (Walla Walla Basin), or the Grande Ronde Basin in 2000. We did implant radio transmitters in two bull trout incidentally captured in the John Day River near the confluence of the North Fork John Day River. In Mill Creek, we used traps to capture migrant bull trout to obtain data for the third successive year in this stream. With these traps, we intended to determine the timing of bull trout movements both upstream and downstream, and to determine the relative abundance, size and age of migrant fish. Because we captured migrant bull trout with traps for three years in the upper John Day River and its tributaries (Hemmingsen, Bellerud, Buchanan, Gunckel, Shappart and Howell 2001; Hemmingsen, Bellerud, Gunckel and Howell 2001; Hemmingsen, Gunckel and Howell 2001) and traps were no longer needed to capture bull trout for radio-tagging, no traps were operated in the John Day Basin in 2000

  14. Life history of the sea lamprey of Cayugaf Lake, New York

    Science.gov (United States)

    Wigley, Roland L.

    1959-01-01

    A life history study of the sea lamprey, Petromyson marinus Linnaeus, in Cayuga Lake, N.Y., was conducted during 1950, 1951, and 1952. One of the major objectives was to obtain biological data concerning this endemic stock of sea lampreys for comparison with the newly established stocks in the Great Lakes. Sexually mature sea lampreys captured on their spawning migration in Cayuga Inlet were the basis of much of this study. Such items as meristic counts, body proportions, body color, sex ratios, lengths and weights, fecundity, rate of upstream travel, effect of dams in retarding upstream movement, nesting habits, parasites, predators, estimates of abundance, and morphological changes were based on mature upstream migrants. Sea lampreys were procured by weir and trap operations and captured by hand. Tagging and marking' programs each spring made it possible to determine movements and morphological changes of individual lampreys, in addition to estimating the number of upstream migrants. Growth of parasitic-phase sea lampreys was estimated from measurements of specimens captured in Cayuga Inlet and Cayuga Lake proper. The incubation period of lamprey eggs and the habits of ammocoetes and transforming lampreys were ascertained from specimens kept in hatchery troughs and raceways. Length-frequency and weight-frequency distributions, together with the length-weight regression, of ammocoetes from Cayuga Inlet were utilized for estimating the duration of their larval life. Lake trout, Salvelinus n. namayc"Ush (Walbaum), from Cayuga Lake and Seneca Lake were the subject of an inquiry into the effects of sea lamprey attacks. Incidence of sea lamprey attacks on the white sucker, Catosto7llus c. commerson/: (LacepMe), was investigated. Three methods are suggested for reducing the number of sea lampreys in Cayuga Lake.

  15. Laboratory evaluation of a lake trout bioenergetics model

    Science.gov (United States)

    Madenjian, Charles P.; O'Connor, Daniel V.

    1999-01-01

    Lake trout Salvelinus namaycush, aged 3 and 6 years and with average weights of 700 and 2,000 g, were grown in laboratory tanks for up to 407 d under a thermal regime similar to that experienced by lake trout in nearshore Lake Michigan. Lake trout were fed alewifeAlosa pseudoharengus and rainbow smelt Osmerus mordax, prey typical of lake trout in Lake Michigan. Of the 120 lake trout used in the experiment, 40 were fed a low ration (0.25% of their body weight per day), 40 were fed a medium ration (0.5% of their body weight per day), and 40 were fed a high ration (ad libitum). We measured consumption and growth, and we compared observed consumption with that predicted by the Wisconsin bioenergetics model. For lake trout fed the medium ration, model predictions for monthly consumption were unbiased. Moreover, predicted cumulative consumption by medium-ration lake trout for the entire experiment (320 d for smaller lake trout and 407 d for larger lake trout) agreed quite well with observed cumulative consumption; predictions were as close as within 0.1 to 5.2% of observed cumulative consumption. Even so, the model consistently overestimated consumption by low-ration fish and underestimated consumption by high-ration fish. The bias was significant in both cases, but was more severe for the low-ration trout. Because the low-ration and high-ration regimes were probably unrealistic for lake trout residing in Lake Michigan and because the model fit our laboratory data rather well for medium-ration trout, we conclude that applying the Wisconsin bioenergetics model to the Lake Michigan lake trout population in order to estimate the amount of prey fish consumed by lake trout each year is appropriate.

  16. 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

    Science.gov (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.

    2015-01-01

    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.

  17. Development and evaluation of a bioenergetics model for bull trout

    Science.gov (United States)

    Mesa, Matthew G.; Welland, Lisa K.; Christiansen, Helena E.; Sauter, Sally T.; Beauchamp, David A.

    2013-01-01

    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.

  18. Using bioenergetics modeling to estimate consumption of native juvenile salmonids by nonnative northern pike in the Upper Flathead River System, Montana

    Science.gov (United States)

    Muhlfeld, C.C.; Bennett, D.H.; Kirk, Steinhorst R.; Marotz, B.; Boyer, M.

    2008-01-01

    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.

  19. Comparative bioenergetics modeling of two Lake Trout morphotypes

    Science.gov (United States)

    Kepler, Megan V.; Wagner, Tyler; Sweka, John A.

    2014-01-01

    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

  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

    2003-03-01

    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. Decline of shortjaw cisco in Lake Superior: the role of overfishing and risk of extinction

    Science.gov (United States)

    Bronte, Charles R.; Hoff, Michael H.; Gorman, Owen T.; Thogmartin, Wayne E.; Schneeberger, Philip J.; Todd, Thomas N.

    2010-01-01

    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.

  2. Biochemistry and metabolism of lake trout: laboratory and field studies on the effects of contaminants

    Science.gov (United States)

    Passino, Dora R. May

    1981-01-01

    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.

  3. Evaluation of the Life History of Native Salmonids in the Malheur River Basin; Cooperative Bull Trout/Redband Trout Research Project, 1999-2000 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    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)

    2000-11-01

    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.

  4. Ecological factors affecting Rainbow Smelt recruitment in the main basin of Lake Huron, 1976-2010

    Science.gov (United States)

    O'Brien, Timothy P.; Taylor, William W.; Roseman, Edward F.; Madenjian, Charles P.; Riley, Stephen C.

    2014-01-01

    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

  5. Effect of artificial sunlight on the retention of external calcein marks on lake trout

    Science.gov (United States)

    Honeyfield, D.C.; Kehler, T.; Fletcher, J.W.; Mohler, J.W.

    2008-01-01

    When choosing a fish marking technique to address fishery related questions, it is important to consider factors that affect mark retention. Calcein, a chemical marking agent, is under investigation for potential use on fish. Two laboratory trials were conducted with calcein-marked lake trout Salvelinus namaycush to determine the effect of artificial sunlight on calcein mark intensity. In trial 1, fish exposed to 18,000 lx for 7 d lost 90% or more of the calcein mark intensity (relative to the colorimetric key, mg/L) on the head, body, ventral region, and pectoral fins relative to mark intensity in fish that were maintained in darkness. In trial 2, light intensity was reduced 2.5-3.0-fold. After 7 d of light exposure, calcein mark intensity on the head was reduced by 40-45% relative to mark intensity in fish that were held in darkness; by day 14, calcein mark intensity on the head was reduced by 55-60% relative to that of dark-treated fish. No further decline was observed in light-exposed fish, and head mark intensity values did not differ among days 14, 21, and 28 for this treatment group. Of the four areas evaluated, the head and pectoral fin were more easily read using a colorimetric key than the lateral or ventral regions of the fish. The concentration of calcein spotted on filter paper to devise the colorimetric key ranged from 1 to 100 mg/L. A difference of approximately 7 mg/L in apparent calcein mark intensity means for the head region could be detected using the colorimetric key. These trials showed that calcein mark intensity on lake trout declined when fish were exposed to artificial sunlight, and the use of a colorimetric key improved the objectivity of calcein mark intensity assessment.

  6. A framework for assessing the feasibility of native fish conservation translocations: Applications to threatened bull trout

    Science.gov (United States)

    Galloway, Benjamin T.; Muhlfeld, Clint C.; Guy, Christopher S.; Downs, Christopher C.; Fredenberg, Wade A.

    2016-01-01

    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.

  7. Abundance indices for determining the status of lake trout restoration in Michigan waters of Lake Superior

    Science.gov (United States)

    Hansen, Michael J.; Schorfhaar, Richard G.; Peck, James W.; Selgeby, James H.; Taylor, William W.

    1995-01-01

    Self-sustaining populations of lake trout Salvelinus namaycush have returned to most areas in Lake Superior, but progress toward achieving historic commercial yields has been difficult to measure because of unrecorded losses to predation by sea lamprey Petromyzon marinus and to fisheries. Consequently, we developed restoration targets (catch per effort, CPE; geometric mean number per kilometer of 114-mm stretch-meaure gill net during 1929-1943, when historic yields were sustained) from linear relationships between CPE in commercial and assessment fisheries in Michigan. Target CPEs for lake trout restoration were higher and less variable than the modern CPEs in all areas. Modern CPEs generally increased during the 1970s and early 1980s but declined during the late 1980s and early 1990s. Modern CPEs were highest in western Michigan from the Keweenaw Peninsula to Marquette (71 to 81% of target CPEs), but coefficients of variation (CV,SD/mean) of mean CPEs were 1.4 to 2.4 times greater than target CVs. Around Munising, the modern CPE was lower (41% of the target CPE), whereas the CV was 1.9 times greater than the target CV. Around Grand Marais, the modern CPE was lowest among all areas (17% of the target CPE), but the CV was nearly the same (1.1 times the target CV). In Whitefish Bay, the modern CPE was only 28% of the target CPE and the CV was 9.0 times greater, though the modern period was based on only the years 1979-1982 and 1984-1985. Further progress in restoration in most areas can be achieved only if fishery managers adequately protect existing stocks of wild fish from sea lamprey predation and fishery exploitation.

  8. Stunning fish with CO2 or electricity: contradictory results on behavioural and physiological stress responses.

    Science.gov (United States)

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

    2016-02-01

    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. PMID:25959256

  9. Potential strategies for recovery of lake whitefish and lake herring stocks in eastern Lake Erie

    Science.gov (United States)

    Oldenburg, K.; Stapanian, M.A.; Ryan, P.A.; Holm, E.

    2007-01-01

    Lake Erie sustained large populations of ciscoes (Salmonidae: Coregoninae) 120 years ago. By the end of the 19th century, abundance of lake whitefish (Coregonus clupeaformis) had declined drastically. By 1925, the lake herring (a cisco) population (Coregonus artedii) had collapsed, although a limited lake herring fishery persisted in the eastern basin until the 1950s. In the latter part of the 20th century, the composition of the fish community changed as oligotrophication proceeded. Since 1984, a limited recovery of lake whitefish has occurred, however no recovery was evident for lake herring. Current ecological conditions in Lake Erie probably will not inhibit recovery of the coregonine species. Recovery of walleye (Sander vitreus) and efforts to rehabilitate the native lake trout (Salvelinus namaycush) in Lake Erie will probably assist recovery because these piscivores reduce populations of alewife (Alosa psuedoharengus) and rainbow smelt (Osmerus mordax), which inhibit reproductive success of coregonines. Although there are considerable spawning substrates available to coregonine species in eastern Lake Erie, eggs and fry would probably be displaced by storm surge from most shoals. Site selection for stocking or seeding of eggs should consider the reproductive life cycle of the stocked fish and suitable protection from storm events. Two potential sites in the eastern basin have been identified. Recommended management procedures, including commercial fisheries, are suggested to assist in recovery. Stocking in the eastern basin of Lake Erie is recommended for both species, as conditions are adequate and the native spawning population in the eastern basin is low. For lake herring, consideration should be given to match ecophenotypes as much as possible. Egg seeding is recommended. Egg seeding of lake whitefish should be considered initially, with fingerling or yearling stocking suggested if unsuccessful. Spawning stocks of whitefish in the western basin of Lake

  10. 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: l5tran@uwaterloo.ca [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: m3power@uwaterloo.ca [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2015-03-15

    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.

  11. 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

    2001-01-01

    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.

  12. Populations protection and territories management in nuclear emergency and post-accident situation

    International Nuclear Information System (INIS)

    for the management of post-accident consequences: agricultural activities and exit of the emergency stage (B. Cessac); 18 - presentation of the operational means of the GIE Groupe Intra (A. Cochard); 19 - synthetical presentation of the studies of post-accident management conditions in the milk industry (G. Machenaud); 20 - reconstruction of doses received by exposed populations (J.R. Jourdain); 21 - organisation of the health monitoring of populations after a radiological accident - presentation taken from the recommendations of the Codirpa's working group 'health stakes' (P. Pirard); 22 - losses indemnification in case of nuclear accident (M. Leger); 23 - post nuclear accident communication - reflections of the Codirpa's working group 'communication' (E. Bouchot); 24 - the ANCCLI's permanent group 'territories - post-accident' (M. Demet); 25 - experience feedback from the local information commission (CLI) 'Marcoule-Gard' in the management of a post-accident situation (J.P. Charre); 26 - commitment of intervening parties in the preparation to accident and post-accident situations: European experiences (T. Schneider); 27 - socio-cognitive exposure and risk assessment - the radio waves case (M. Poumadere). (J.S.)

  13. Starch molecular fractionation of bread wheat varieties Fraccionamiento molecular del almidón de variedades trigo pan

    Directory of Open Access Journals (Sweden)

    V. Corcuera

    2007-06-01

    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

  14. Fingerprints of environmental stressors in three selected Slovenian gravel-bed rivers: geochemical and isotopic approach

    Science.gov (United States)

    Kanduč, Tjaša; Kocman, David; Debeljak, Barbara; Mori, Nataša

    2016-04-01

    Rivers are severely impacted by a range of simultaneous processes including water pollution, flow and channel alteration, over-fishing, invasive species and climate change. Systematic studies of river water geochemistry provide important information on chemical weathering of bedrock/soil and natural anthropogenic processes that may control the dissolved chemical loads, while the isotopic studies of biological components of river systems (macrophytes, periphyton, heterotrophic biofilm, invertebrates, fish) contribute to the understanding how the system response to human impacts by means of functional response. In this contribution, insights in the fingerprints of various environmental stressors in three gravel-bed rivers (River Kamni\\vska Bistrica, River Idrijca and River Sava) in Slovenia, using geochemical and stable isotope approach are discussed. Gravel bed of all three rivers investigated is composed of carbonates and clastic rocks. The Sava and Kamni\\vska Bistrica Rivers have alpine high mountain snow-rain regime. The Idrijca River is a boundary river between the Adriatic and Black Sea catchments and has rain-snow discharge regime with torrential character. Geochemical methods (ICP-OES, IC, total alkalinity after Gran) and isotope mass - spectrometric methods (isotopic composition of dissolved inorganic carbon, particulate organic carbon and isotopic composition of carbon in carbonates) were used to evaluate biogeochemical processes in rivers. Isotopic composition of carbon and nitrogen of the moss Fontinalis antipyretica (the whole vegetative shoot) and isotopic composition of carbon of heterotrophic biofilm was also analyzed in order to better understand the fluxes and fractionation of carbon and nitrogen across trophic levels. Geochemical composition of all investigated rivers is HCO3‑-Ca2+-Mg2+ with different Mg2+/Ca2+ ratios as follows: around 0.33 for Kamni\\vska Bistrica and River Sava in Slovenia and above 0.75 for River Idrijca. In the Kamni

  15. Quantitative distribution of aquatic plant and animal communities in the Forsmark-area

    International Nuclear Information System (INIS)

    , rock) a luxuriant growth of the bladder wrack (Fucus vesiculosus) could be seen. Also, the moss Fontinalis dalecarlica was not unusual. This moss is frequently observed in the Gulf of Bothnia but does not occur in the Baltic proper. Among the animals, the blue mussel (Mytilus edulis) was to a large extent missing, although suitable substrate was present. In the Bothnian Sea the marine mussel Mytilus extends up to the Northern Quark, but usually only scattered, few individuals are found at each site along the whole coast. The blue mussel never has the same mass-occurrence as can be observed in the Stockholm archipelago and further south in the Baltic proper. Thus, the ecosystem of the SFR-area has a function somewhat different from the Baltic proper as the filter feeders lack to a large extent. The species biomass was determined by collecting 54 quantitative samples (usually 12 samples per transect). At comparable depths, when excluding the bladder wrack (Fucus vesiculosus) and the blue mussel (Mytilus edulis) the total depth distribution of plant and animal biomass was similar those of the Graesoe-Singoe area (ranging between 30-60 g dry weight m-2 of plants and 20-50 g of animals). However, the total biomass of both the bladder wrack (Fucus vesiculosus) and the filter feeding blue mussel (Mytilus edulis) was considerable lower in the Forsmark area. This can to some extent be explained by the difference in dominating substrate (mostly rocky) as well as a larger influence from the Baltic proper in the Graesoe-Singoe area. For the low amounts of Mytilus see explanation given above

  16. Quantitative distribution of aquatic plant and animal communities in the Forsmark-area

    Energy Technology Data Exchange (ETDEWEB)

    Kautsky, H.; Plantman, P.; Borgiel, M. [Stockholm Univ. (Sweden). Dept. of Systems Ecology

    1999-12-15

    (boulders, rock) a luxuriant growth of the bladder wrack (Fucus vesiculosus) could be seen. Also, the moss Fontinalis dalecarlica was not unusual. This moss is frequently observed in the Gulf of Bothnia but does not occur in the Baltic proper. Among the animals, the blue mussel (Mytilus edulis) was to a large extent missing, although suitable substrate was present. In the Bothnian Sea the marine mussel Mytilus extends up to the Northern Quark, but usually only scattered, few individuals are found at each site along the whole coast. The blue mussel never has the same mass-occurrence as can be observed in the Stockholm archipelago and further south in the Baltic proper. Thus, the ecosystem of the SFR-area has a function somewhat different from the Baltic proper as the filter feeders lack to a large extent. The species biomass was determined by collecting 54 quantitative samples (usually 12 samples per transect). At comparable depths, when excluding the bladder wrack (Fucus vesiculosus) and the blue mussel (Mytilus edulis) the total depth distribution of plant and animal biomass was similar those of the Graesoe-Singoe area (ranging between 30-60 g dry weight m{sup -2} of plants and 20-50 g of animals). However, the total biomass of both the bladder wrack (Fucus vesiculosus) and the filter feeding blue mussel (Mytilus edulis) was considerable lower in the Forsmark area. This can to some extent be explained by the difference in dominating substrate (mostly rocky) as well as a larger influence from the Baltic proper in the Graesoe-Singoe area. For the low amounts of Mytilus see explanation given above.

  17. A synthesis of ecological and fish-community changes in Lake Ontario, 1970-2000

    Science.gov (United States)

    Mills, E.L.; Casselman, J.M.; Dermott, R.; Fitzsimons, J.D.; Gal, G.; Holeck, K. T.; Hoyle, J.A.; Johannsson, O.E.; Lantry, B.F.; Makarewicz, J.C.; Millard, E.S.; Munawar, I.F.; Munawar, M.; O'Gorman, R.; Owens, R.W.; Rudstam, L. G.; Schaner, T.; Stewart, T.J.

    2005-01-01

    We assessed stressors associated with ecological and fishcommunity changes in Lake Ontario since 1970, when the first symposium on Salmonid Communities in Oligotrophic Lakes (SCOL I) was held (J. Fish. Res. Board Can. 29: 613-616). Phosphorus controls implemented in the early 1970s were undeniably successful; lower food-web studies showed declines in algal abundance and epilimnetic zooplankton production and a shift in pelagic primary productivity toward smaller organisms. Stressors on the fish community prior to 1970 such as exploitation, sea lamprey (Petromyzon marinus) predation, and effects of nuisance populations of alewife (Alosa pseudoharengus) were largely ameliorated by the 1990s. The alewife became a pivotal species supporting a multi-million-dollar salmonid sport fishery, but alewife-induced thiamine deficiency continued to hamper restoration and sustainability of native lake trout (Salvelinus namaycush). Expanding salmonine populations dependent on alewife raised concerns about predator demand and prey supply, leading to reductions in salmonine stocking in the early 1990s. Relaxation of the predation impact by alewives and their shift to deeper water allowed recovery of native fishes such as threespine stickleback (Gasterosteus aculeatus) and emerald shiner (Notropis atherinoides). The return of the Lake Ontario ecosystem to historical conditions has been impeded by unplanned introductions. Establishment of Dreissena spp. led to increased water clarity and increased vectoring of lower trophic-level production to benthic habitats and contributed to the collapse of Diporeia spp. populations, behavioral modifications of key fish species, and the decline of native lake whitefish (Coregonus clupeaformis). Despite reduced productivity, exotic-species introductions, and changes in the fish community, offshore Mysis relicta populations remained relatively stable. The effects of climate and climate change on the population abundance and dynamics of Lake Ontario

  18. Lake Pend Oreille Predation Research, Annual Report 2002-2003.

    Energy Technology Data Exchange (ETDEWEB)

    Bassista, Thomas

    2004-02-01

    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

  19. Kootenai River Fisheries Investigations; Rainbow and Bull Trout Recruitment, 2002-2003 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Walters, Jody P.

    2004-01-01

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

    International Nuclear Information System (INIS)

    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 (δ13C) and nitrogen (δ15N) 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, δ13C showed that benthic carbon (chironomids) was the dominant food source for char. Regression models of log Hg versus δ15N (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 from 6 Arctic lakes were

  1. Bull Trout Life History, Genetics, Habitat Needs, and Limiting Factors in Central and Northeast Oregon, Annual Report 2001.

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-12-01

    Bull trout Salvelinus confluentus exhibit a number of life history strategies. Stream-resident bull trout complete their life cycle in their natal tributaries. Migratory bull trout spawn in tributary streams where juvenile fish usually spend from one to four years before migrating to either a larger river (fluvial) or lake (adfluvial) where they rear before returning to the tributary stream to spawn (Fraley and Shepard 1989). These migratory forms occur where conditions allow movement from spawning locations to downstream waters that provide greater foraging opportunities (Dunham and Rieman 1999). Resident and migratory forms may occur together, and either form can produce resident or migratory offspring (Rieman and McIntyre 1993). The ability to migrate is important to the persistence of local bull trout populations (Rieman and McIntyre 1993). The identification of migratory corridors can help focus habitat protection efforts. Determining the life history form(s) that comprise local populations, the timing of seasonal movements, and the geographic extent of these movements are critical to bull trout protection and recovery efforts. This section describes work accomplished in 2001 that continued to address two objectives of this project. These objectives are (1) determine the distribution of juvenile and adult bull trout 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 the Grande Ronde and Walla Walla basins, we continued to monitor the movements of bull trout with radio transmitters applied in 1998 (Hemmingsen, Bellerud, Gunckel and Howell 2001) and 1999 (Hemmingsen, Gunckel

  2. Captive Rearing Initiative for Salmon River Chinook Salmon, 1999 Progress Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hassemer, Peter F.

    2001-04-01

    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.

  3. 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

    Science.gov (United States)

    Martens, Kyle D.; Tibbits, Wesley T.; Watson, Grace A.; Newsom, Michael A.; Connolly, Patrick J.

    2014-01-01

    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

  4. Lake trout spawning habitat in the Six Fathom Bank-Yankee Reef lake trout sanctuary, Lake Huron

    Science.gov (United States)

    Edsall, Thomas A.; Brown, Charles L.; Kennedy, Gregory W.; Poe, Thomas P.

    1992-01-01

    Attempts to reestablish self-sustaining stocks of lake trout (Salvelinus namaycush) in the lower four Great Lakes, where the species was extinguished in the 1950s and 1960s, have been largely unsuccessful. To avoid many of the problems believed to be contributing to this failure, the fishery management community recently established several sanctuaries in the offshore waters of the Great Lakes where the development and protection of self-sustaining stocks of lake trout would be a primary management objective. One of these, the Six Fathom Bank-Yankee Reef sanctuary, was created in the south-central portion of Lake Huron. This sanctuary covers 168,000 ha and includes the shallower portions of the Six Fathom and Ipperwash scarps, which are major bathymetric features in the southern half of the lake. Historical accounts describe Six Fathom Bank as the most important lake trout spawning ground in the lake. Here we present the results of lake bed surveys conducted in the sanctuary with side-scan sonar, underwater videocamera systems, and a small research submarine. Our observations of the lake bed are consistent with what is known of the bedrock stratigraphy, glacial history, and karst geomorphology of the Lake Huron basin. Most of the loose rock we found seemed to be derived from local carbonate bedrock formations, although non-carbonate rock probably from Precambrian sources to the north was also present in some areas. Much of the bedrock and loose rock displayed karst solution features described for the Bruce Peninsula on the Ontario shoreline. Our surveys revealed substantial areas of lake bed at water depths of 20–36 m that resembled suitable spawning and fry production habitat for the shallow-water strains of lake trout that are the focus of the rehabilitation effort. Low mid-lake nutrient levels documented recently by others and the extremely high abundance of Mysis relicta (an important item in the diet of young lake trout) that we documented on Yankee Reef

  5. An ecological risk assessment of the exposure and effects of 2,4-D acid to rainbow trout (Onchorhyncus mykiss)

    Science.gov (United States)

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

    2009-01-01

    30-day safety factor of 559 (e.g., 76/0.163). Assessment of the exposure and response data presented herein indicates that use of 2,4-D acid for invasive weed control in aquatic and terrestrial habitats poses no substantial risk to growth or survival of rainbow trout or other salmonids, including the threatened bull trout (Salvelinus confluentus). ?? 2009 US Government.

  6. An ecological risk assessment of the acute and chronic effects of the herbicide clopyralid to rainbow trout (Oncorhynchus mykiss)

    Science.gov (United States)

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

    2009-01-01

    Clopyralid (3,6-dichloro-2-pyridinecarboxylic acid) is a pyridine herbicide frequently used to control invasive, noxious weeds in the northwestern United States. Clopyralid exhibits low acute toxicity to fish, including the rainbow trout (Oncorhynchus mykiss) and the threatened bull trout (Salvelinus confluentus). However, there are no published chronic toxicity data for clopyralid and fish that can be used in ecological risk assessments. We conducted 30-day chronic toxicity studies with juvenile rainbow trout exposed to the acid form of clopyralid. The 30-day maximum acceptable toxicant concentration (MATC) for growth, calculated as the geometric mean of the no observable effect concentration (68 mg/L) and the lowest observable effect concentration (136 mg/L), was 96 mg/L. No mortality was measured at the highest chronic concentration tested (273 mg/L). The acute:chronic ratio, calculated by dividing the previously published 96-h acutely lethal concentration (96-h ALC50; 700 mg/L) by the MATC was 7.3. Toxicity values were compared to a four-tiered exposure assessment profile assuming an application rate of 1.12 kg/ha. The Tier 1 exposure estimation, based on direct overspray of a 2-m deep pond, was 0.055 mg/L. The Tier 2 maximum exposure estimate, based on the Generic Exposure Estimate Concentration model (GEENEC), was 0.057 mg/L. The Tier 3 maximum exposure estimate, based on previously published results of the Groundwater Loading Effects of Agricultural Management Systems model (GLEAMS), was 0.073 mg/L. The Tier 4 exposure estimate, based on published edge-of-field monitoring data, was estimated at 0.008 mg/L. Comparison of toxicity data to estimated environmental concentrations of clopyralid indicates that the safety factor for rainbow trout exposed to clopyralid at labeled use rates exceeds 1000. Therefore, the herbicide presents little to no risk to rainbow trout or other salmonids such as the threatened bull trout. ?? 2009 US Government.

  7. Using High-Resolution Models to Predict the Effects of Climate Change on Aquatic Ecosystems in the Crown of the Continent

    Science.gov (United States)

    Jones, L.; Muhlfeld, C.; Marshall, L. A.

    2013-12-01

    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

  8. Radiological impact of the nuclear power plant accident on freshwater fish in Fukushima: An overview of monitoring results.

    Science.gov (United States)

    Wada, Toshihiro; Tomiya, Atsushi; Enomoto, Masahiro; Sato, Toshiyuki; Morishita, Daigo; Izumi, Shigehiko; Niizeki, Kouji; Suzuki, Shunji; Morita, Takami; Kawata, Gyo

    2016-01-01

    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

  9. Bull trout population assessment in the Columbia River Gorge/annual report fy2000; ANNUAL

    International Nuclear Information System (INIS)

    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 and lt;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

  10. A biomonitoring plan for assessing potential radionuclide exposure using Amchitka Island in the Aleutian chain of Alaska as a case study

    International Nuclear Information System (INIS)

    trossulus), dolly varden (Salvelinus malma), black rockfish (Sebastes melanops), Pacific cod (Gadus macrocephalus), Pacific halibut (Hippoglossus stenolepis), and glaucous-winged gull (Larus glaucescens) as bioindicators. This combination of species included mainly subsistence foods, commercial fish, and nodes on different food chains

  11. Piscivorous fish exhibit temperature-influenced binge feeding during an annual prey pulse.

    Science.gov (United States)

    Furey, Nathan B; Hinch, Scott G; Mesa, Matthew G; Beauchamp, David A

    2016-09-01

    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

  12. Captive Rearing Initiative for Salmon River Chinook Salmon, 1998-1999 Progress Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hassemer, Peter F.

    2001-04-01

    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.

  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: glescord@gmail.com [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)

    2015-03-15

    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. Effects of climate change and wildfire on stream temperatures and salmonid thermal habitat in a mountain river network.

    Science.gov (United States)

    Isaak, Daniel J; Luce, Charles H; Rieman, Bruce E; Nagel, David E; Peterson, Erin E; Horan, Dona L; Parkes, Sharon; Chandler, Gwynne L

    2010-07-01

    Mountain streams provide important habitats for many species, but their faunas are especially vulnerable to climate change because of ectothermic physiologies and movements that are constrained to linear networks that are easily fragmented. Effectively conserving biodiversity in these systems requires accurate downscaling of climatic trends to local habitat conditions, but downscaling is difficult in complex terrains given diverse microclimates and mediation of stream heat budgets by local conditions. We compiled a stream temperature database (n = 780) for a 2500-km river network in central Idaho to assess possible trends in summer temperatures and thermal habitat for two native salmonid species from 1993 to 2006. New spatial statistical models that account for network topology were parameterized with these data and explained 93% and 86% of the variation in mean stream temperatures and maximas, respectively. During our study period, basin average mean stream temperatures increased by 0.38 degrees C (0.27 degrees C/decade), and maximas increased by 0.48 degrees C (0.34 degrees C/decade), primarily due to long-term (30-50 year) trends in air temperatures and stream flows. Radiation increases from wildfires accounted for 9% of basin-scale temperature increases, despite burning 14% of the basin. Within wildfire perimeters, however, stream temperature increases were 2-3 times greater than basin averages, and radiation gains accounted for 50% of warming. Thermal habitat for rainbow trout (Oncorhynchus mykiss) was minimally affected by temperature increases, except for small shifts towards higher elevations. Bull trout (Salvelinus confluentus), in contrast, were estimated to have lost 11-20% (8-16%/decade) of the headwater stream lengths that were cold enough for spawning and early juvenile rearing, with the largest losses occurring in the coldest habitats. Our results suggest that a warming climate has begun to affect thermal conditions in streams and that impacts to

  15. 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.

    2003-06-01

    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

  16. 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)

    2005-11-01

    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

  17. 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)

    2004-04-01

    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

  18. 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.

    2004-02-01

    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

  19. 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

    2002-11-01

    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

  20. 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

    2008-11-20

    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

  1. The physiology and toxicology of salmonid eggs and larvae in relation to water quality criteria

    International Nuclear Information System (INIS)

    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

  2. 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: nigel.finn@bio.uib.no

    2007-03-30

    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

  3. 牙鲆胰岛素样生长因子结合蛋白IGFBP-1cDNA全长的克隆及表达分析%The full-length cDNA cloning and gene expression analysis of insulin-like growth factor binding protein 1 (IGFBP-1)in Japanese flounder ( Paralichthys olivaceus )

    Institute of Scientific and Technical Information of China (English)

    翟万营; 张俊玲; 施志仪; 李巍

    2012-01-01

    The full-length cDNA of insulin- like growth factor binding protein 1 gene (IGFBP-1) was obtained from the liver of Japanese flounder (Paralichthys olivaceus) using RACE method. The complete cDNA of P. olivaceus IGFBP-1 is 1 070 bp and its ORF includes 729 bp encoding 242 amino acid residues. The IGFBP-1 was highly homologous with IGFBP-1 gene in fish through phylogency analysis. The nucleotide sequence of IGFBP-1 from P. olivaceus shared 95% homology with that of Scophthalmus maximu, and the deduced amino acid analysis showed that the sequence similarities between P. olivaceus and 5. Maximu, Seriola quinqueradiata, Perca flavescens, Salvelinus alpines, Cyprinus carpio and Danio rerio, are 89% ,89% ,84% ,79% ,67% and 67% .respectively. Semi-quantitative RT-PCR results demonstrated that IGFBP-1 mRNA was detected in unfertilized egg, fertilized egg, embryonic and larval development, and various adult tissues. Moreover, real-time quantitative RT-PCR results showed that IGFBP-1 gene had the highest expression in adult liver and was expressed in a stage-specific manner during embryonic and larval development.%利用RACE-PCR技术,从牙鲆肝脏组织总RNA中克隆得到胰岛素样生长因子结合蛋白-1(insulin-like growth factor binding protein 1,IGFBP-1)基因的全长cDNA序列,该cDNA全长为1 070 bp,开放阅读框为729 bp,编码242个氨基酸.通过系统进化树分析,牙鲆IGFBP-1与鱼类IGFBP-1基因紧密聚为一支;通过同源性比对,牙鲆IGFBP-1基因的核苷酸序列与大菱鲆同源性最高,为95%,而其推导的氨基酸序列与其它鱼类如大菱鲆、五条(蛳)、黄金鲈、红点鲑、鲤和斑马鱼的同源性分别为89%、89%、84%、79%、67%和67%.半定量RT-PCR显示,牙鲆IGFBP-1 mRNA在未受精卵、受精卵、胚胎、仔鱼发育各阶段及成体各组织均被检测.荧光定量RT-PCR结果表明,牙鲆IGFBP-1基因在成鱼肝脏中表达量最高,且在胚胎和仔鱼发育期间具有明显的时期特异性.

  4. Hangman Restoration Project : Annual Report, August 1, 2001 - July 31, 2002.

    Energy Technology Data Exchange (ETDEWEB)

    Green, Gerald I.; Coeur D' Alene Tribe.

    2002-06-01

    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

  5. Implications of climate change for the fishes of the British Isles.

    Science.gov (United States)

    Graham, C T; Harrod, C

    2009-04-01

    temperatures are likely to favour cool-adapted (e.g. Perca fluviatilis) and warm-adapted freshwater fishes (e.g. roach Rutilus rutilus and other cyprinids) whose distribution and reproductive success may currently be constrained by temperature rather than by cold-adapted species (e.g. salmonids). Species that occur in Britain and Ireland that are at the edge of their distribution will be most affected, both negatively and positively. Populations of conservation importance (e.g.Salvelinus alpinus and Coregonus spp.) may decline irreversibly. However, changes in food-web dynamics and physiological adaptation, for example because of climate change, may obscure or alter predicted responses. The residual inertia in climate systems is such that even a complete cessation in emissions would still leave fishes exposed to continued climate change for at least half a century. Hence, regardless of the success or failure of programmes aimed at curbing climate change, major changes in fish communities can be expected over the next 50 years with a concomitant need to adapt management strategies accordingly. PMID:20735625

  6. Kootenai River Fisheries Investigations; Rainbow and Bull Trout Recruitment, 2003-2004 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Walters, Jody P.

    2005-08-01

    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

  7. 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

    2009-07-01

    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

  8. 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

    Science.gov (United States)

    Martens, Kyle D.; Fish, Teresa M.; Watson, Grace A.; Connolly, Patrick J.

    2014-01-01

    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

  9. 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)

    1995-07-01

    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

  10. 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

    2004-04-01

    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

  11. 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

    2003-12-01

    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

  12. Coeur d'Alene Tribe Fish and Wildlife Program Habitat Protection Plan; Implementation of Fisheries Enhancement Opportunities on the Coeur d'Alene Reservation, 1997-2002 Technical Report.

    Energy Technology Data Exchange (ETDEWEB)

    Vitale, Angelo; Roberts, Frank; Peters, Ronald

    2002-06-01

    Throughout the last century, the cumulative effects of anthropogenic disturbances have caused drastic watershed level landscape changes throughout the Reservation and surrounding areas (Coeur d'Alene Tribe 1998). Changes include stream channelization, wetland draining, forest and palouse prairie conversion for agricultural use, high road density, elimination of old growth timber stands, and denuding riparian communities. The significance of these changes is manifested in the degradation of habitats supporting native flora and fauna. Consequently, populations of native fish, wildlife, and plants, which the Tribe relies on as subsistence resources, have declined or in some instances been extirpated (Apperson et al. 1988; Coeur d'Alene Tribe 1998; Lillengreen et al. 1996; Lillengreen et al. 1993; Gerry Green Coeur d'Alene Tribe wildlife Biologist, personal communication 2002). For example, bull trout (Salvelinus confluentus) are not present at detectable levels in Reservation tributaries, westslope cutthroat trout (Oncorhynchus clarki lewisi) are not present in numbers commensurate with maintaining harvestable fisheries (Lillengreen et al. 1993, 1996), and the Sharp-tailed grouse (Tympanuchus phasianellus) are not present at detectable levels on the Reservation (Gerry Green, Coeur d'Alene Tribe wildlife biologist, personal communication). The Coeur d'Alene Tribe added Fisheries and Wildlife Programs to their Natural Resources Department to address these losses and protect important cultural, and subsistence resources for future generations. The Tribal Council adopted by Resolution 89(94), the following mission statement for the Fisheries Program: 'restore, protect, expand and re-establish fish populations to sustainable levels to provide harvest opportunities'. This mission statement, focused on fisheries restoration and rehabilitation, is a response to native fish population declines throughout the Tribe's aboriginal territory