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Sample records for brook trout salvelinus

  1. Environmental DNA particle size distribution from Brook Trout (Salvelinus fontinalis)

    Science.gov (United States)

    Taylor M. Wilcox; Kevin S. McKelvey; Michael K. Young; Winsor H. Lowe; Michael K. Schwartz

    2015-01-01

    Environmental DNA (eDNA) sampling has become a widespread approach for detecting aquatic animals with high potential for improving conservation biology. However, little research has been done to determine the size of particles targeted by eDNA surveys. In this study, we conduct particle distribution analysis of eDNA from a captive Brook Trout (Salvelinus fontinalis) in...

  2. 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.

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

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    Horká Petra

    2017-01-01

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

  4. Brook trout (Salvelinus fontinalis extinction in small boreal lakes revealed by ephippia pigmentation: a preliminary analysis

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    Alexandre Bérubé Tellier

    2016-12-01

    Full Text Available Ephippium pigmentation is a plastic trait which can be related to a trade-off between visual predation pressure and better protection of cladoceran eggs against different types of stress. Experimental studies showed that planktivorous fish exert a greater predation pressure on individuals carrying darker ephippia, but little is known about the variation of ephippium pigmentation along gradients of fish predation pressure in natural conditions. For this study, our experimental design included four small boreal lakes with known fish assemblages. Two of the lakes have viable brook trout (Salvelinus fontinalis populations, whereas the other two lakes experienced brook trout extinctions during the 20th century. Cladoceran ephippia were extracted from sediment cores at layers corresponding to the documented post- extinction phase (1990's and from an older layer (1950's for which the brook trout population status is not known precisely. Our first objective was to determine whether brook trout extinction has a direct effect on both ephippium pigmentation and size. Our second objective was to give a preliminary assessment of the status of brook trout populations in the 1950's by comparing the variation in ephippia traits measured from this layer to those measured in the 1990's, for which the extinction patterns are well known. Cost-effective image analysis was used to assess variation in pigmentation levels in ephippia. This approach provided a proxy for the amount of melanin invested in each ephippium analysed. Our study clearly shows that ephippium pigmentation may represent a better indicator of the presence of fish predators than ephippium size, a trait that showed a less clear pattern of variation between lakes with and without fish. For the 1990's period, ephippia from fishless lakes were darker and showed a slight tendency to be larger than ephippia from lakes with brook trout. However, no clear differences in either ephippium size or pigmentation

  5. Draft genome sequence of a picorna-like virus associated with gill tissue in clinically normal brook trout, Salvelinus fontinalis

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    Iwanowicz, Luke; Iwanowicz, Deborah; Adams, Cynthia; Galbraith, Heather S.; Aunins, Aaron W.; Cornman, Robert S.

    2017-01-01

    Here, we report a draft genome sequence of a picorna-like virus associated with brook trout, Salvelinus fontinalis, gill tissue. The draft genome comprises 8,681 nucleotides, excluding the poly(A) tract, and contains two open reading frames. It is most similar to picorna-like viruses that infect invertebrates.

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

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    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.

  7. Biological Responses in Brook Trout (Salvelinus fontinalis) Caged Downstream from Municipal Wastewater Treatment Plants in the Credit River, ON, Canada.

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    McGovarin, Stephen; Sultana, Tamanna; Metcalfe, Chris

    2017-12-11

    To determine whether discharges of contaminants from municipal wastewater treatment plants (WWTPs) may be contributing to the decline in populations of brook trout (Salvelinus fontinalis) in the watershed of the Credit River in ON, Canada, we caged juvenile brook trout upstream and downstream of the WWTPs of the small communities of Acton and Orangeville. Levels of vitellogenin were significantly elevated in liver tissue of trout caged downstream of both WWTPs, indicating exposure to estrogenic substances. Levels of thiobarbituric acid reactive substances indicative of oxidation of lipids were elevated in the gill tissue of brook trout caged downstream of the Orangeville WWTP, and levels of total glutathione were significantly lower in the gills of brook trout caged downstream of the Acton WWTP. Both biomarkers are indicative of oxidative stress, although many constituents of wastewater could be responsible for these responses. More work is needed to determine whether discharges of wastewater are contributing to the decline of brook trout in the Credit River and other cold-water streams in the Lake Ontario catchment basin.

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

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    David C Kazyak

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

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

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

    2011-01-01

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

  10. pH preference and avoidance responses of adult brook trout Salvelinus fontinalis and brown trout Salmo trutta.

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    Fost, B A; Ferreri, C P

    2015-03-01

    The pH preferred and avoided by wild, adult brook trout Salvelinus fontinalis and brown trout Salmo trutta was examined in a series a laboratory tests using gradual and steep-gradient flow-through aquaria. The results were compared with those published for the observed segregation patterns of juvenile S. fontinalis and S. trutta in Pennsylvania streams. The adult S. trutta tested showed a preference for pH 4·0 while adult S. fontinalis did not prefer any pH within the range tested. Salmo trutta are not found in Pennsylvania streams with a base-flow pH pH well above 4·0. Adult S. trutta displayed a lack of avoidance at pH below 5·0, as also reported earlier for juveniles. The avoidance pH of wild, adult S. fontinalis (between pH 5·5 and 6·0) and S. trutta (between pH 6·5 and 7·0) did not differ appreciably from earlier study results for the avoidance pH of juvenile S. fontinalis and S. trutta. A comparison of c.i. around these avoidance estimates indicates that avoidance pH is similar among adult S. fontinalis and S. trutta in this study. The limited overlap of c.i. for avoidance pH values for the two species, however, suggests that some S. trutta will display avoidance at a higher pH when S. fontinalis will not. The results of this study indicate that segregation patterns of adult S. fontinalis and S. trutta in Pennsylvania streams could be related to pH and that competition with S. trutta could be mediating the occurrence of S. fontinalis at some pH levels. © 2015 The Fisheries Society of the British Isles.

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

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    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.

  12. 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)

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    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.

  13. Nature and time course of acclimation to aluminum in juvenile brook trout (Salvelinus fontinalis): II. Gill histology

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    Mueller, M.E.; Sanchez, D.A.; Bergman, H.L.; McDonald, D.G.; Rhem, R.G.; Wood, C.M.

    1991-01-01

    Gill samples from juvenile brook trout (Salvelinus fontinalis) acclimated to low-level aluminum at pH 5.2 showed severe damage by day 4, with necrosis and fusion of secondary lamellae and hyperplasia and hypertrophy of mucous cells. Over the following 20 d, there was a continual process of repair with proliferation and hypertrophy of mucous cells. Qualitative analysis of gill samples plus physiology and mortality data collected in a companion study indicated progressive development (by day 10 onward) of increasing acclimation to Al. Quantitative analysis of gill samples on day 13 showed that mucous cell volume density had tripled and mucous cell area had doubled in Al-exposed fish compared with control fish. A lamellar fusion index showed evidence of fusion in Al-exposed fish by day 4 with recovery to nearly control levels by day 13. Physiological disturbances appear to be directly related to the histological changes observed in the gill epithelium. At the cellular level, changes in either mucous cell production and secretion or changes in mucus chemistry contribute, in part, to acclimation to Al.

  14. Sex reversal of brook trout (Salvelinus fontinalis) by 17α-methyltestosterone exposure: A serial experimental approach to determine optimal timing and delivery regimes.

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    Fatima, Shafaq; Adams, Mark; Wilkinson, Ryan

    2016-12-01

    Commercial culture of Brook trout (Salvelinus fontinalis) in Tasmania was partly abandoned due to sexual maturation of male fish early on during the estuarine rearing phase. Maturation adversely affects body mass, flesh quality and immunocompetency effectively. Sex reversal techniques such as the in-feed addition of a synthetic androgen have proven difficult to adapt in brook trout. An appropriate timing, duration and delivery vehicle for administration of 17α-methyltestosterone (MT) to produce phenotypic males (neomales) from genotypically female brook trout required further investigation. In this study, groups of brook trout eggs (n=1000) maintained at 9.5±0.15-10±0.14°C, were immersed in MT (400μgL -1 ) for four hours on two alternate days (two immersions/group) staggered over a two week period surrounding the hatch of embryos (control groups excluded). The groups were then split and half received MT-supplemented feed for 60days and the other a standard diet. Following an 11 month on-growing period sex phenotypes were determined by gross & histological gonad morphology. The highest proportion of male phenotypes (75%) was found in fish immersed six and four days pre-hatch and subsequently fed a normal diet. Fish fed a MT supplemented diet and immersed in MT showed significantly higher proportions of sterile fish. These data indicate that a pre-hatch immersion-only regime (4-6days pre-hatch at 9.5°C) should be pursued as a target for optimization studies to further refine the effective concentration and duration of exposure to MT for the successful production of neo-male brook trout. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Exotic "Gill Lice" Species (Copepoda: Lernaeopodidae: Salmincola SPP.) Infect Rainbow Trout (Oncorhynchus mykiss) and Brook Trout (Salvelinus fontinalis) in the Southeastern United States.

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    Ruiz, Carlos F; Rash, Jacob M; Besler, Doug A; Roberts, Jackson R; Warren, Micah B; Arias, Cova R; Bullard, Stephen A

    2017-08-01

    Salmincola californiensis infected 25 of 31 (prevalence 0.8; intensity 2-35 [mean 6.6 ± standard deviation 7.7; n = 25]) rainbow trout, Oncorhynchus mykiss, from a private trout farm connected to the Watauga River, North Carolina. Salmincola edwardsii infected all of 9 (1.0; 2-43 [9.3 ± 13.0; 9]) brook trout, Salvelinus fontinalis, from Big Norton Prong, a tributary of the Little Tennessee River, North Carolina. Both lernaeopodids are well-known salmonid pathogens, but neither is native to, nor has been previously taxonomically confirmed from, the southeastern United States. Herein, we (1) use light and scanning electron microscopy to identify and provide supplemental morphological observations of these lernaeopodids, (2) furnish complementary molecular sequence data from the 28S rDNA (28S), and (3) document the pathological effects of gill infections. We identified and differentiated these lernaeopodids by the second antenna (exopod tip with large [S. californiensis] vs. slender [S. edwardsii] spines; endopod terminal segment with subequal ventral processes shorter than [S. californiensis] vs. longer than or equal to [S. edwardsii] dorsal hook), maxilliped palp (length typically ≤1/3 [S. californiensis] vs. 1/3-1/2 [S. edwardsii] subchela length exclusive of claw), and bulla (sub-circular and concave on manubrium's side [S. californiensis] vs. non-stellate [S. edwardsii]). Analysis of the 28S rDNA sequences confirmed our taxonomic assignments as demonstrated by 100% sequence similarity among the sympatric, morphologically-conspecific isolates. Histopathology revealed focal gill epithelial hyperplasia, obstruction of interlamellar water channels, lamellar fusion, and crypting of gill filaments. High intensity infections by either lernaeopodid are surveillance-worthy because they are potentially pathogenic to trout in the southeastern United States.

  16. Great Smoky Mountains National Park Brook Trout Genetics

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

  17. 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...

  18. Comparison of continuous and episodic exposure to acidic, aluminum-contaminated waters of brook trout (Salvelinus fontinalis)

    Energy Technology Data Exchange (ETDEWEB)

    Siddens, L.K.; Seim, W.K.; Curtis, L.R.; Chapman, G.A.

    1986-01-01

    This study demonstrated that repetitive, intermittent exposures to aluminum (Al) under acidic conditions produced greater cumulative mortality and lower growth rates of brook trout than would be extrapolated from continuous exposure experiments. During a 24-d study, exposures were at pH 4.4 or 4.9 with 0.2-1.2 mg Al-L-1. Data were analyzed based on peak and 24-d mean Al concentrations of continuous and intermittent (2-d toxicant, 4-d ambient condition cycle) exposures. Survival was lower in groups exposed at pH 4.9 than those at 4.4 when intermittently exposed but not when continuously exposed. Growth rates were less for fish continuously exposed at pH 4.4 compared with those at pH 4.9, while intermittent exposures to Al acidity alone did not affect growth. Fish intermittently exposed to Al at pH 4.4 grew faster than those at pH 4.9, indicating greater Al toxicity at the higher pH. (Copyright (c) Canadian Journal of Fisheries and Aquatic Sciences, Vol. 43, 1986.)

  19. Hatching, growth, ion accumulation, and skeletal ossification of brook trout (Salvelinus fontinalis) alevins in acidic soft waters

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    Steingraeber, M.T.; Gingerich, W.H.

    1991-01-01

    Brook trout eyed eggs and subsequent alevins were exposed to pH 5.0, 6.5, and 7.0 in soft reconstituted water and to pH 8.2 in hard well water for up to 72 d. Hatching was delayed and hatching success reduced (p K+ > Cl- during yolk absorption and early exogenous feeding. Whole-body monovalent ion concentrations were reduced for short periods during yolk absorption in alevins exposed to pH 6.5 and throughout most of the experiment for those exposed to pH 5.0. Whole-body Mg2+ concentrations were not affected by treatment pH and remained near their median hatch level throughout the exposure. The whole-body concentration of Ca2+ was reduced in fish exposed to pH 5.0, particularly near the end of the experiment. Calcium accumulation in fish was influenced by the interaction of pH and time at pH 5.0 but not at the other pH levels. Alevins exposed to pH 5.0 experienced delayed ossification of skeletal structures associated with feeding, respiration, and locomotion that usually persisted for up to 10 d. The detection of skeletal abnormalities early in life might aid in identifying fish populations at risk in acidified waters.

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

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    McKenna, 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

  1. Species-specific sensitivity to selenium-induced impairment of cortisol secretion in adrenocortical cells of rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis).

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    Miller, L L; Hontela, A

    2011-06-01

    Species differences in physiological and biochemical attributes exist even among closely related species and may underlie species-specific sensitivity to toxicants. Rainbow trout (RT) are more sensitive than brook trout (BT) to the teratogenic effects of selenium (Se), but it is not known whether all tissues exhibit this pattern of vulnerability. In this study, primary cultures of RT and BT adrenocortical cells were exposed to selenite (Na(2)SO(3)) and selenomethionine (Se-Met) to compare cell viability and ACTH-stimulated cortisol secretion in the two fish species. Cortisol, the primary stress hormone in fish, facilitates maintenance of homeostasis when fish are exposed to stressors, including toxicants. Cell viability was not affected by Se, but selenite impaired cortisol secretion, while Se-Met did not (RT and BT EC(50)>2000mg/L). RT cells were more sensitive (EC(50)=8.7mg/L) to selenite than BT cells (EC(50)=90.4mg/L). To identify the targets where Se disrupts cortisol synthesis, selenite-impaired RT and BT cells were stimulated with ACTH, dbcAMP, OH-cholesterol, and pregnenolone. Selenite acted at different steps in the cortisol biosynthesis pathway in RT and BT cells, confirming a species-specific toxicity mechanism. To test the hypothesis that oxidative stress mediates Se-induced toxicity, selenite-impaired RT cells were exposed to NAC, BSO and antioxidants (DETCA, ATA, Vit A, and Vit E). Inhibition of SOD by DETCA enhanced selenite-induced cortisol impairment, indicating that oxidative stress plays a role in Se toxicity; however, modifying GSH content of the cells did not have an effect. The results of this study, with two closely related salmonids, provided additional evidence for species-specific differences in sensitivity to Se which should be considered when setting thresholds and water quality guidelines. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Rainbow trout versus brook trout biomass and production under varied climate regimes in small southern Appalachian streams

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    Bonnie. J.E. Myers; C. Andrew Dolloff; Andrew L. Rypel

    2014-01-01

    Many Appalachian streams historically dominated by Brook Trout Salvelinus fontinalis have experienced shifts towards fish communities dominated by Rainbow Trout Onchorhynchus mykiss. We used empirical estimates of biomass and secondary production of trout conspecifics to evaluate species success under varied thermal regimes. Trout...

  3. Fall and winter survival of brook trout and brown trout in a north-central Pennsylvania watershed

    Science.gov (United States)

    Sweka, John A.; Davis, Lori A.; Wagner, Tyler

    2017-01-01

    Stream-dwelling salmonids that spawn in the fall generally experience their lowest survival during the fall and winter due to behavioral changes associated with spawning and energetic deficiencies during this time of year. We used data from Brook Trout Salvelinus fontinalis and Brown Trout Salmo trutta implanted with radio transmitters in tributaries of the Hunts Run watershed of north-central Pennsylvania to estimate survival from the fall into the winter seasons (September 2012–February 2013). We examined the effects that individual-level covariates (trout species, size, and movement rates) and stream-level covariates (individual stream and cumulative drainage area of a stream) have on survival. Brook Trout experienced significantly lower survival than Brown Trout, especially in the early fall during their peak spawning period. Besides a significant species effect, none of the other covariates examined influenced survival for either species. A difference in life history between these species, with Brook Trout having a shorter life expectancy than Brown Trout, is likely the primary reason for the lower survival of Brook Trout. However, Brook Trout also spawn earlier in the fall than Brown Trout and low flows during Brook Trout spawning may have resulted in a greater risk of predation for Brook Trout compared with Brown Trout, thereby also contributing to the observed differences in survival between these species. Our estimates of survival can aid parameterization of future population models for Brook Trout and Brown Trout through the spawning season and into winter.

  4. Esterification and hydrolysis of vitamin A in the liver of brook trout (Salvelinus fontinalis) and the influence of a coplanar polychlorinated biphenyl

    Energy Technology Data Exchange (ETDEWEB)

    Ndayibagira, A.; Spear, P.A. [Centre de Recherche TOXEN and Departement des Sciences Biologiques, Universite du Quebec a Montreal, C.P. 8888, succursale Centre Ville Montreal (Canada)

    1999-03-01

    Recent reports of extremely low retinoid stores in fish living in contaminated river systems prompted an initial investigation of the mechanisms of hepatic storage and mobilization in brook trout. Enzyme characterization in microsomes revealed a lecithin:retinol acyltransferase activity (LRAT) optimum in the alkaline range (pH 9.0; V{sub max}=0.6 nmol per mg prot. h{sup -1}; K{sub m}=10.2 {mu}M) which is not known to occur in mammals, in addition to a secondary optimum at pH 6.5 typical of mammals. Acyl CoA:retinol acyltransferase (ARAT) kinetic parameters were quite different to those of mammals. The substrate affinity of trout ARAT (K{sub m}=1.6 {mu}M) was approximately 22-fold greater than that of the rat while maximal velocity (V{sub max}=0.2 nmol per mg prot. h{sup -1}) was 18-fold less. Retinyl ester hydrolase activity (REH) was optimal under acid conditions (pH 4.2; V{sub max}=6.6 nmol per mg prot. h{sup -1}; K{sub m}=0.6 mM), was inhibited by a bile salt analogue and was greater in males than females. This REH was tentatively categorized as a bile salt-independent, acid retinyl ester hydrolase (BSI-AREH). REH was inhibited in a dose-dependent manner following in vivo exposure to a representative environmental contaminant the coplanar polychlorinated biphenyl (PCB), 3,3minutes or feet,4,4minutes or feet-tetrachlorobiphenyl (TCBP). Inhibition may be an indirect effect because enzyme activity was not affected by in vitro exposure of control microsomes. REH inhibition in the brook trout may affect the uptake of retinyl esters (REs) from chylomicron remnants as well as the mobilization of stored REs. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  5. Brook trout use of thermal refugia and foraging habitat influenced by brown trout

    Science.gov (United States)

    Hitt, Nathaniel P.; Snook, Erin; Massie, Danielle L.

    2017-01-01

    The distribution of native brook trout (Salvelinus fontinalis) in eastern North America is often limited by temperature and introduced brown trout (Salmo trutta), the relative importance of which is poorly understood but critical for conservation and restoration planning. We evaluated effects of brown trout on brook trout behavior and habitat use in experimental streams across increasing temperatures (14–23 °C) with simulated groundwater upwelling zones providing thermal refugia (6–9 °C below ambient temperatures). Allopatric and sympatric trout populations increased their use of upwelling zones as ambient temperatures increased, demonstrating the importance of groundwater as thermal refugia in warming streams. Allopatric brook trout showed greater movement rates and more even spatial distributions within streams than sympatric brook trout, suggesting interference competition by brown trout for access to forage habitats located outside thermal refugia. Our results indicate that removal of introduced brown trout may facilitate native brook trout expansion and population viability in downstream reaches depending in part on the spatial configuration of groundwater upwelling zones.

  6. 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.

  7. A Vegetation Survey of Trout Brook Flowage

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Trout Brook structure was started in 1963 under the Accelerated Public Works Program and finished in the summer of 1965. There is a 200 foot earthdike, a metal...

  8. Use of cover habitat by bull trout Salvelinus confluentus and lake trout Salvelinus namaycush in a laboratory environment

    Science.gov (United States)

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

    2011-01-01

    Lacustrine-adfluvial bull trout, Salvelinus confluentus, migrate from spawning and rearing streams to lacustrine environments as early as age 0. Within lacustrine environments, cover habitat pro- vides refuge from potential predators and is a resource that is competed for if limiting. Competitive inter- actions between bull trout and other species could result in bull trout being displaced from cover habitat, and bull trout may lack evolutionary adaptations to compete with introduced species, such as lake trout, Salvelinus namaycush. A laboratory experiment was performed to examine habitat use and interactions for cover by juvenile (i.e., <80 mm total length) bull trout and lake trout. Differences were observed between bull trout and lake trout in the proportion of time using cover (F1,22.6=20.08, P<0.001) and bottom (F1,23.7 = 37.01, P < 0.001) habitat, with bull trout using cover and bottom habitats more than lake trout. Habitat selection ratios indicated that bull trout avoided water column habitat in the presence of lake trout and that lake trout avoided bottom habitat. Intraspecific and interspecific agonistic interactions were infrequent, but approximately 10 times greater for intraspecific inter- actions between lake trout. Results from this study provide little evidence that juvenile bull trout and lake trout compete for cover, and that species-specific differences in habitat use and selection likely result in habitat partitioning between these species.

  9. The effects of varied densities on the growth and emigration of adult cutthroat trout and brook trout in fenced stream enclosures

    Science.gov (United States)

    Buys, D.J.; Hilderbrand, R.H.; Kershner, J.L.

    2009-01-01

    We evaluated the effects of various density treatments on adult fish growth and emigration rates between Bonneville cutthroat trout Oncorhynchus clarki utah and brook trout Salvelinus fontinalis in stream enclosures in Beaver Creek, Idaho, We used 3 density treatments (low, ambient, and high fish densities) to evaluate density-related effects and to ensure a response. Intraspecific ambient-density tests using cutthroat trout only were also performed. Results indicated an absence of cage effects in the stream enclosures and no differences in fish growth between ambient-density stream-enclosure fish and free-range fish. Brook trout outgrew and moved less than cutthroat trout in the stream enclosures, especially as density increased, In all 3 density treatments, brook trout gained more weight than cutthroat trout, with brook trout gaining weight in each density treatment and cutthroat trout losing weight at the highest density. At high densities, cutthroat trout attempted to emigrate more frequently than brook trout in sympatry and allopatry. We observed a negative correlation between growth and emigration for interspecific cutthroat trout, indicating a possible competitive response due to the presence of brook trout. We observed similar responses for weight and emigration in trials of allopatric cutthroat trout, indicating strong intraspecific effects as density increased. While cutthroat trout showed a response to experimental manipulation with brook trout at different densities, there has been long-term coexistence between these species in Beaver Creek, This system presents a unique opportunity to study the mechanisms that lead cutthroat trout to coexist with rather than be replaced by nonnative brook trout.

  10. 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.

  11. Structured decision making for conservation of bull trout (Salvelinus confluentus) in Long Creek, Klamath River Basin, south-central Oregon

    Science.gov (United States)

    Benjamin, Joseph R.; McDonnell, Kevin; Dunham, Jason B.; Brignon, William R.; Peterson, James T.

    2017-06-21

    With the decline of bull trout (Salvelinus confluentus), managers face multiple, and sometimes contradictory, management alternatives for species recovery. Moreover, effective decision-making involves all stakeholders influenced by the decisions (such as Tribal, State, Federal, private, and non-governmental organizations) because they represent diverse objectives, jurisdictions, policy mandates, and opinions of the best management strategy. The process of structured decision making is explicitly designed to address these elements of the decision making process. Here we report on an application of structured decision making to a population of bull trout believed threatened by high densities of nonnative brook trout (S. fontinalis) and habitat fragmentation in Long Creek, a tributary to the Sycan River in the Klamath River Basin, south-central Oregon. This involved engaging stakeholders to identify (1) their fundamental objectives for the conservation of bull trout, (2) feasible management alternatives to achieve their objectives, and (3) biological information and assumptions to incorporate in a decision model. Model simulations suggested an overarching theme among the top decision alternatives, which was a need to simultaneously control brook trout and ensure that the migratory tactic of bull trout can be expressed. More specifically, the optimal management decision, based on the estimated adult abundance at year 10, was to combine the eradication of brook trout from Long Creek with improvement of downstream conditions (for example, connectivity or habitat conditions). Other top decisions included these actions independently, as well as electrofishing removal of brook trout. In contrast, translocating bull trout to a different stream or installing a barrier to prevent upstream spread of brook trout had minimal or negative effects on the bull trout population. Moreover, sensitivity analyses suggested that these actions were consistently identified as optimal across

  12. Landscape models of brook trout abundance and distribution in lotic habitat with field validation

    Science.gov (United States)

    McKenna, James E.; Johnson, James H.

    2011-01-01

    Brook trout Salvelinus fontinalis are native fish in decline owing to environmental changes. Predictions of their potential distribution and a better understanding of their relationship to habitat conditions would enhance the management and conservation of this valuable species. We used over 7,800 brook trout observations throughout New York State and georeferenced, multiscale landscape condition data to develop four regionally specific artificial neural network models to predict brook trout abundance in rivers and streams. Land cover data provided a general signature of human activity, but other habitat variables were resistant to anthropogenic changes (i.e., changing on a geological time scale). The resulting models predict the potential for any stream to support brook trout. The models were validated by holding 20% of the data out as a test set and by comparison with additional field collections from a variety of habitat types. The models performed well, explaining more than 90% of data variability. Errors were often associated with small spatial displacements of predicted values. When compared with the additional field collections (39 sites), 92% of the predictions were off by only a single class from the field-observed abundances. Among “least-disturbed” field collection sites, all predictions were correct or off by a single abundance class, except for one where brown trout Salmo trutta were present. Other degrading factors were evident at most sites where brook trout were absent or less abundant than predicted. The most important habitat variables included landscape slope, stream and drainage network sizes, water temperature, and extent of forest cover. Predicted brook trout abundances were applied to all New York streams, providing a synoptic map of the distribution of brook trout habitat potential. These fish models set benchmarks of best potential for streams to support brook trout under broad-scale human influences and can assist with planning and

  13. 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.

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

    Science.gov (United States)

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

    2016-01-01

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

  15. Simulated effects of YY-male stocking and manual suppression for eradicating nonnative Brook Trout populations

    Science.gov (United States)

    Schill, Daniel J.; Meyer, Kevin A.; Hansen, Michael J.

    2017-01-01

    Eradication of nonnative Brook Trout Salvelinus fontinalis populations is difficult to achieve with standard techniques, such as electrofishing removal or piscicides; new approaches are needed. A novel concept is to stock “supermale” hatchery fish with wild conspecifics. Supermales (MYY) have two Y-chromosomes, resulting in offspring that are all males; over time, successful supermale reproduction could eradicate the wild population. We constructed an age-structured stochastic model to investigate the effects of manually suppressing wild fish and stocking MYY fingerlings on the long-term viability of hypothetical nonnative Brook Trout populations. In streams, an annual stocking rate of supermales equivalent to 50% of wild age-0 Brook Trout density combined with an annual selective suppression rate equivalent to 50% of wild Brook Trout density resulted in a time to extirpation of only 2–4 years if supermale fitness was equivalent to wild male fitness. However, time to extirpation in streams was 5–15 years if supermale fitness was 80% lower than wild male fitness. In alpine lakes, higher supermale stocking rates and nonselective gillnetting were required to eradicate Brook Trout populations. If supermales were assumed to be as fit as wild males, however, any supermale stocking rate greater than 49% in alpine lakes or 60% in streams achieved eradication in 10 years or less, regardless of the suppression rate. Because manual suppression and the stocking of MYY fingerlings can readily be conducted at the levels assumed in our simulations, use of such an integrated pest management (IPM) approach could extirpate undesirable Brook Trout populations within reasonably short periods of time. Given the recent successful development of an MYY Brook Trout broodstock capable of producing large numbers of MYY fingerlings and given the positive results of the present simulations for both streams and alpine lakes, field testing of MYY stocking is warranted within an

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

    Science.gov (United States)

    Benjamin H. Letcher; Jason A Coombs; Keith H. Nislow

    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...

  17. Dose-dependent stimulation of hepatic retinoic acid hydroxylation/oxidation and glucuronidation in brook trout, Salvelinus fontinalis, after exposure to 3,3{prime}, 4,4{prime}-tetrachlorobiphenyl

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, P.M.; Ndayibagira, A.; Spear, P.A.

    2000-03-01

    Extremely low stores of vitamin A have been reported in fish and birds inhabiting regions contaminated by coplanar polychlorinated biphenyls (PCBs) and other organochlorines, suggesting many possible effects on retinoid biochemical pathways. Metabolic imbalances associated with biologically active retinoids (e.g., retinoic acid) could be associated with tetratogenesis, edema, growth inhibition, reproductive impairment, immunosuppression, and susceptibility to cancer. Sexually mature brook trout were injected imtraperitoneally with the coplanar PCB 3,3{prime}, 4,4{prime}-tetrachlorobiphenyl (TCBP) and again 4 weeks later. At 8 weeks, retinoic acid metabolism was measured in liver microsomes. To the authors' knowledge, retinoic acid conjugation by UDP-glucuronyltransferase is described here for the first time in fish. A substantial rate of glucuronidation was detected in the microsomes from control brook trout, which tended to increase over the dose range of TCBP. Glucuronidation was significantly greater in fish receiving the 10 {micro}g/g body weight dose level. Metabolism through the cytochrome P450 system was also dose-dependent, resulting in significantly greater production of 4-hydroxyretinoic acid at the 10 {micro}g/g dose level. In contrast, subsequent oxidation to 4-oxo-retinoic acid was greatest at the 1 {micro}g/g dose level and did not increase further at higher doses. Liver stores of dehydroretinyl palmitate/oleate were significantly decreased at the 5 and 10 {micro}g/g dose levels.

  18. Is motivation important to brook trout passage through culverts?

    Science.gov (United States)

    Goerig, Elsa; Castro-Santos, Theodore R.

    2017-01-01

    Culverts can restrict movement of stream-dwelling fish. Motivation to enter and ascend these structures is an essential precursor for successful passage. However, motivation is challenging to quantify. Here, we use attempt rate to assess motivation of 447 brook trout (Salvelinus fontinalis) entering three culverts under a range of hydraulic, environmental, and biological conditions. A passive integrated transponder system allowed for the identification of passage attempts and success of individual fish. Attempt rate was quantified using time-to-event analysis allowing for time-varying covariates and recurrent events. Attempt rate was greatest during the spawning period, at elevated discharge, at dusk, and for longer fish. It decreased during the day and with increasing number of conspecifics downstream of the culvert. Results also show a positive correlation between elevated motivation and successful passage. This study enhances understanding of factors influencing brook trout motivation to ascend culverts and shows that attempt rate is a dynamic phenomenon, variable over time and among individuals. It also presents methods that could be used to investigate other species’ motivation to pass natural or anthropogenic barriers.

  19. Movement patterns of Brook Trout in a restored coastal stream system in southern Massachusetts

    Science.gov (United States)

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

    2016-01-01

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

  20. Biological consequences of the coaster brook trout restoration stocking program in Lake Superior tributaries with Pictured Rocks National Lakeshore

    Science.gov (United States)

    Leonard, Jill B.K.; Stott, Wendylee; Loope, Delora M.; Kusnierz, Paul C.; Sreenivasan, Ashwin

    2013-01-01

    The coaster Brook Trout Salvelinus fontinalis is a Lake Superior ecotype representing intraspecific variation that has been impacted by habitat loss and overfishing. Hatchery strains of Brook Trout derived from populations in Lake Superior were stocked into streams within Pictured Rocks National Lakeshore, Michigan, as part of an effort to rehabilitate adfluvial coaster Brook Trout. Wild and hatchery Brook Trout from three streams (Mosquito River, Hurricane River, and Sevenmile Creek) were examined for movement behavior, size, physiology, and reproductive success. Behavior and size of the stocked fish were similar to those of wild fish, and less than 15% of the stocked, tagged Brook Trout emigrated from the river into which they were stocked. There was little evidence of successful reproduction by stocked Brook Trout. Similar to the results of other studies, our findings suggest that the stocking of nonlocal Brook Trout strains where a local population already exists results in limited natural reproduction and should be avoided, particularly if the mechanisms governing the ecotype of interest are poorly understood.

  1. Efficacy of environmental DNA to detect and quantify Brook Trout populations in headwater streams of the Adirondack Mountains, New York

    Science.gov (United States)

    Baldigo, Barry P.; Sporn, Lee Ann; George, Scott D.; Ball, Jacob

    2016-01-01

    Environmental DNA (eDNA) analysis is rapidly evolving as a tool for monitoring the distributions of aquatic species. Detection of species’ populations in streams may be challenging because the persistence time for intact DNA fragments is unknown and because eDNA is diluted and dispersed by dynamic hydrological processes. During 2015, the DNA of Brook Trout Salvelinus fontinalis was analyzed from water samples collected at 40 streams across the Adirondack region of upstate New York, where Brook Trout populations were recently quantified. Study objectives were to evaluate different sampling methods and the ability of eDNA to accurately predict the presence and abundance of resident Brook Trout populations. Results from three-pass electrofishing surveys indicated that Brook Trout were absent from 10 sites and were present in low (300 fish/0.1 ha) densities at 9, 11, and 10 sites, respectively. The eDNA results correctly predicted the presence and confirmed the absence of Brook Trout at 85.0–92.5% of the study sites; eDNA also explained 44% of the variability in Brook Trout population density and 24% of the variability in biomass. These findings indicate that eDNA surveys will enable researchers to effectively characterize the presence and abundance of Brook Trout and other species’ populations in headwater streams across the Adirondack region and elsewhere.

  2. Shale Gas Development and Brook Trout: Scaling Best Management Practices to Anticipate Cumulative Effects

    Science.gov (United States)

    Smith, David; Snyder, Craig D.; Hitt, Nathaniel P.; Young, John A.; Faulkner, Stephen P.

    2012-01-01

    Shale gas development may involve trade-offs between energy development and benefits provided by natural ecosystems. However, current best management practices (BMPs) focus on mitigating localized ecological degradation. We review evidence for cumulative effects of natural gas development on brook trout (Salvelinus fontinalis) and conclude that BMPs should account for potential watershed-scale effects in addition to localized influences. The challenge is to develop BMPs in the face of uncertainty in the predicted response of brook trout to landscape-scale disturbance caused by gas extraction. We propose a decision-analysis approach to formulating BMPs in the specific case of relatively undisturbed watersheds where there is consensus to maintain brook trout populations during gas development. The decision analysis was informed by existing empirical models that describe brook trout occupancy responses to landscape disturbance and set bounds on the uncertainty in the predicted responses to shale gas development. The decision analysis showed that a high efficiency of gas development (e.g., 1 well pad per square mile and 7 acres per pad) was critical to achieving a win-win solution characterized by maintaining brook trout and maximizing extraction of available gas. This finding was invariant to uncertainty in predicted response of brook trout to watershed-level disturbance. However, as the efficiency of gas development decreased, the optimal BMP depended on the predicted response, and there was considerable potential value in discriminating among predictive models through adaptive management or research. The proposed decision-analysis framework provides an opportunity to anticipate the cumulative effects of shale gas development, account for uncertainty, and inform management decisions at the appropriate spatial scales.

  3. 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.

  4. Scale-Dependent Seasonal Pool Habitat Use by Sympatric Wild Brook Trout and Brown Trout Populations

    National Research Council Canada - National Science Library

    Davis, Lori A; Wagner, Tyler

    2016-01-01

    .... Discrete-choice models were used to (1) evaluate fall and early winter daytime habitat use by sympatric Brook Trout and Brown Trout populations based on available residual pool habitat within a stream network and (2...

  5. Brook Trout Distribution, Pacific Northwest (updated March, 2006)

    Data.gov (United States)

    Pacific States Marine Fisheries Commission — This dataset is a record of fish distribution and activity for BROOK TROUT contained in the StreamNet database. This feature class was created based on linear event...

  6. Spatial and temporal Brook Trout density dynamics: Implications for conservation, management, and monitoring

    Science.gov (United States)

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

    2014-01-01

    Many potential stressors to aquatic environments operate over large spatial scales, prompting the need to assess and monitor both site-specific and regional dynamics of fish populations. We used hierarchical Bayesian models to evaluate the spatial and temporal variability in density and capture probability of age-1 and older Brook Trout Salvelinus fontinalis from three-pass removal data collected at 291 sites over a 37-year time period (1975–2011) in Pennsylvania streams. There was high between-year variability in density, with annual posterior means ranging from 2.1 to 10.2 fish/100 m2; however, there was no significant long-term linear trend. Brook Trout density was positively correlated with elevation and negatively correlated with percent developed land use in the network catchment. Probability of capture did not vary substantially across sites or years but was negatively correlated with mean stream width. Because of the low spatiotemporal variation in capture probability and a strong correlation between first-pass CPUE (catch/min) and three-pass removal density estimates, the use of an abundance index based on first-pass CPUE could represent a cost-effective alternative to conducting multiple-pass removal sampling for some Brook Trout monitoring and assessment objectives. Single-pass indices may be particularly relevant for monitoring objectives that do not require precise site-specific estimates, such as regional monitoring programs that are designed to detect long-term linear trends in density.

  7. Multiscale hydrogeomorphic influences on bull trout (Salvelinus confluentus) spawning habitat

    Science.gov (United States)

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

    2015-01-01

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

  8. Brook trout distributional response to unconventional oil and gas development: Landscape context matters.

    Science.gov (United States)

    Merriam, Eric R; Petty, J Todd; Maloney, Kelly O; Young, John A; Faulkner, Stephen P; Slonecker, E Terrence; Milheim, Lesley E; Hailegiorgis, Atesmachew; Niles, Jonathan

    2018-02-11

    We conducted a large-scale assessment of unconventional oil and gas (UOG) development effects on brook trout (Salvelinus fontinalis) distribution. We compiled 2231 brook trout collection records from the Upper Susquehanna River Watershed, USA. We used boosted regression tree (BRT) analysis to predict occurrence probability at the 1:24,000 stream-segment scale as a function of natural and anthropogenic landscape and climatic attributes. We then evaluated the importance of landscape context (i.e., pre-existing natural habitat quality and anthropogenic degradation) in modulating the effects of UOG on brook trout distribution under UOG development scenarios. BRT made use of 5 anthropogenic (28% relative influence) and 7 natural (72% relative influence) variables to model occurrence with a high degree of accuracy [Area Under the Receiver Operating Curve (AUC)=0.85 and cross-validated AUC=0.81]. UOG development impacted 11% (n=2784) of streams and resulted in a loss of predicted occurrence in 126 (4%). Most streams impacted by UOG had unsuitable underlying natural habitat quality (n=1220; 44%). Brook trout were predicted to be absent from an additional 26% (n=733) of streams due to pre-existing non-UOG land uses (i.e., agriculture, residential and commercial development, or historic mining). Streams with a predicted and observed (via existing pre- and post-disturbance fish sampling records) loss of occurrence due to UOG tended to have intermediate natural habitat quality and/or intermediate levels of non-UOG stress. Simulated development of permitted but undeveloped UOG wells (n=943) resulted in a loss of predicted occurrence in 27 additional streams. Loss of occurrence was strongly dependent upon landscape context, suggesting effects of current and future UOG development are likely most relevant in streams near the probability threshold due to pre-existing habitat degradation. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Differences in low pH tolerance among strains of brook trout (Salvelinum fontinalis)

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, G.D.; Dunson, W.A.; Wright, J.E.; Mamolito, G.E.

    1976-01-01

    Survival time of brook trout (Salvelinus fontinalis mitchill) at low pH was directly related to size, and inversely related to temperature. Between pH 2.50 and 3.25 an increase in pH by increments of 0.25 each led to a 2-3 fold increase in survival time. At higher pH's (3.25-3.75) elevations in pH by the same increments each produced a 3-5 fold increase. Brook trout tested at pH 3.35 and 3.50 showed maximum survival times in June-August. Members of seven inbred lines of brook trout were tested for acid tolerance; the lines differed markedly providing strong evidence that acid tolerance is hereditary. Tests involving either intercrossed or backcrossed offspring of tolerant or intolerant parentals demonstrated intermediate survival in 12.5% of all experiments and heterosis in 66.7% of the tests. Differences in survival of inbred lines were the most marked at pH 3.25. Exposure for 1 week at pH 3.75 resulted in a 20-25% decrease in survival time of 18 fish tested at pH 2.50 and 3.00. Out of a total of 24 trout (17 g) tested at pH 3.75 two highly tolerant individuals were still alive after 6.1 weeks. Thus it is likely that a strain resistant to a pH below 4.1, the previously recorded lower limit, can be developed by selective breeding.

  10. 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...

  11. Spatial structure of morphological and neutral genetic variation in Brook Trout

    Science.gov (United States)

    Kazyak, David C.; Hilderbrand, Robert H.; Keller, Stephen R.; Colaw, Mark C.; Holloway, Amanda E.; Morgan, Raymond P.; King, Timothy L.

    2015-01-01

    Brook Trout Salvelinus fontinalis exhibit exceptional levels of life history variation, remarkable genetic variability, and fine-scale population structure. In many cases, neighboring populations may be highly differentiated from one another to an extent that is comparable with species-level distinctions in other taxa. Although genetic samples have been collected from hundreds of populations and tens of thousands of individuals, little is known about whether differentiation at neutral markers reflects phenotypic differences among Brook Trout populations. We compared differentiation in morphology and neutral molecular markers among populations from four geographically proximate locations (all within 24 km) to examine how genetic diversity covaries with morphology. We found significant differences among and/or within streams for all three morphological axes examined and identified the source stream of many individuals based on morphology (52.3% classification efficiency). Although molecular and morphological differentiation among streams ranged considerably (mean pairwise FST: 0.023–0.264; pairwise PST: 0.000–0.339), the two measures were not significantly correlated. While in some cases morphological characters appear to have diverged to a greater extent than expected by neutral genetic drift, many traits were conserved to a greater extent than were neutral genetic markers. Thus, while Brook Trout exhibit fine-scale spatial patterns in both morphology and neutral genetic diversity, these types of biological variabilities are being structured by different ecological and evolutionary processes. The relative influences of genetic drift versus selection and phenotypic plasticity in shaping morphology appear to vary among populations occupying nearby streams.

  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

    Full Text Available Abstract Background Salmonids are regarded as 4R derivative species, having experienced 4 whole genome duplication events in their ancestry. Many duplicated chromosome regions still share extensive homology with one another which is maintained primarily through male-based homeologous chromosome pairings during meiosis. The formation of quadrivalents during meiosis leads to pseudolinkage. This phenomenon is more prevalent within 5 of the 12 ancestral teleost linkage groups in salmonids. Results We constructed a genetic linkage map for brook charr and used this in combination with the genetic map from Arctic charr, to make comparisons with the genetic map of rainbow trout. Although not all chromosome arms are currently mapped, some homologous chromosome rearrangements were evident between Arctic charr and brook charr. Notably, 10 chromosome arms in brook charr representing 5 metacentric chromosomes in Arctic charr have undergone rearrangements. Three metacentrics have one arm translocated and fused with another chromosome arm in brook charr to a make a new metacentrics while two metacentrics are represented by 4 acrocentric pairs in brook charr. In two cases (i.e., BC-4 and BC-16, an apparent polymorphism was observed with the identification of both a putative metacentric structure (similar to metacentric AC-4 = BC-4 and a joining of acrocentric AC-16 + one arm of AC-28 = BC-16, as well as two separate acrocentric linkage groups evident in the mapping parents. Forty-six of the expected 50 karyotypic arms could be inter-generically assigned. SEX in brook charr (BC-4 was localized to the same homologous linkage group region as in Arctic charr (AC-4. The homeologous affinities detected in the two charr species facilitated the identification of 20 (expected number = 25 shared syntenic regions with rainbow trout, although it is likely that some of these regions were partial or overlapping arm regions. Conclusions Inter-generic comparisons among 2

  13. The temperature-productivity squeeze: Constraints on brook trout growth along an Appalachian river continuum

    Science.gov (United States)

    Petty, J. Todd; Thorne, David; Huntsman, Brock M.; Mazik, Patricia M.

    2014-01-01

    We tested the hypothesis that brook trout growth rates are controlled by a complex interaction of food availability, water temperature, and competitor density. We quantified trout diet, growth, and consumption in small headwater tributaries characterized as cold with low food and high trout density, larger tributaries characterized as cold with moderate food and moderate trout density, and large main stems characterized as warm with high food and low trout density. Brook trout consumption was highest in the main stem where diets shifted from insects in headwaters to fishes and crayfish in larger streams. Despite high water temperatures, trout growth rates also were consistently highest in the main stem, likely due to competitively dominant trout monopolizing thermal refugia. Temporal changes in trout density had a direct negative effect on brook trout growth rates. Our results suggest that competition for food constrains brook trout growth in small streams, but access to thermal refugia in productive main stem habitats enables dominant trout to supplement growth at a watershed scale. Brook trout conservation in this region should seek to relieve the “temperature-productivity squeeze,” whereby brook trout productivity is constrained by access to habitats that provide both suitable water temperature and sufficient prey.

  14. Climate change and vulnerability of bull trout (Salvelinus confluentus ) in a fire-prone landscape

    Science.gov (United States)

    Jeffrey A. Falke; Rebecca L. Flitcroft; Jason B. Dunham; Kristina M. McNyset; Paul F. Hessburg; Gordon H. Reeves; C. Tara Marshall

    2015-01-01

    Linked atmospheric and wildfire changes will complicate future management of native coldwater fishes in fire-prone landscapes, and new approaches to management that incorporate uncertainty are needed to address this challenge. We used a Bayesian network (BN) approach to evaluate population vulnerability of bull trout (Salvelinus confluentus) in the Wenatchee River...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-11-15

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

  16. Acidic Groundwater Discharge and in Situ Egg Survival in Redds of Lake-Spawning Brook Trout

    National Research Council Canada - National Science Library

    Warren, Dana R; Sebestyen, Stephen D; Josephson, Daniel C; Lepak, Jesse M; Kraft, Clifford E

    2005-01-01

    .... While most studies have reported that groundwater discharge in brook trout redds is buffered relative to the surrounding lake water, we documented brook trout spawning over an area of acidic groundwater discharge (pH as low as 4.7...

  17. Evidence of sound production by spawning lake trout (Salvelinus namaycush) in lakes Huron and Champlain

    Science.gov (United States)

    Johnson, Nicholas S.; Higgs, Dennis; Binder, Thomas R.; Marsden, J. Ellen; Buchinger, Tyler John; Brege, Linnea; Bruning, Tyler; Farha, Steve A.; Krueger, Charles C.

    2017-01-01

    Two sounds associated with spawning lake trout (Salvelinus namaycush) in lakes Huron and Champlain were characterized by comparing sound recordings to behavioral data collected using acoustic telemetry and video. These sounds were named growls and snaps, and were heard on lake trout spawning reefs, but not on a non-spawning reef, and were more common at night than during the day. Growls also occurred more often during the spawning period than the pre-spawning period, while the trend for snaps was reversed. In a laboratory flume, sounds occurred when male lake trout were displaying spawning behaviors; growls when males were quivering and parallel swimming, and snaps when males moved their jaw. Combining our results with the observation of possible sound production by spawning splake (Salvelinus fontinalis × Salvelinus namaycush hybrid), provides rare evidence for spawning-related sound production by a salmonid, or any other fish in the superorder Protacanthopterygii. Further characterization of these sounds could be useful for lake trout assessment, restoration, and control.

  18. Histopathology of fish. IV. A granuloma of brook trout

    Science.gov (United States)

    Wood, E.M.; Yasutake, W.T.

    1956-01-01

    In the summer of 1952, Snieszko and Griffin (1955) diagnosed kidney disease in brook trout from the Fish and Wildlife Service's station at Berlin, New Hampshire. During the examination of these fish, a peculiar lesion was observed in the vicinity of the gastric caeca. In very advanced cases, hard, glistening, white masses of tissue bearing a striking resemblance to mature testes often filled the abdominal cavity. In the initial examinations, the material was actually mistaken for normal testicular tissue. Subsequently, it was recognized as an entirely aberrant, proliferating tumor-like mass.

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

    Directory of Open Access Journals (Sweden)

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

    2012-02-01

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

  20. Experimental test of genetic rescue in isolated populations of brook trout

    Science.gov (United States)

    Robinson, Zachary L.; Coombs, Jason A.; Hudy, Mark; Nislow, Keith H.; Letcher, Benjamin H.; Whiteley, Andrew R.

    2017-01-01

    Genetic rescue is an increasingly considered conservation measure to address genetic erosion associated with habitat loss and fragmentation. The resulting gene flow from facilitating migration may improve fitness and adaptive potential, but is not without risks (e.g., outbreeding depression). Here, we conducted a test of genetic rescue by translocating ten (five of each sex) brook trout (Salvelinus fontinalis) from a single source to four nearby and isolated stream populations. To control for the demographic contribution of translocated individuals, ten resident individuals (five of each sex) were removed from each recipient population. Prior to the introduction of translocated individuals, the two smallest above-barrier populations had substantially lower genetic diversity, and all populations had reduced effective number of breeders relative to adjacent below-barrier populations. In the first reproductive bout following translocation, 31 of 40 (78%) translocated individuals reproduced successfully. Translocated individuals contributed to more families than expected under random mating and generally produced larger full-sibling families. We observed relatively high (>20%) introgression in three of the four recipient populations. The translocations increased genetic diversity of recipient populations by 45% in allelic richness and 25% in expected heterozygosity. Additionally, strong evidence of hybrid vigour was observed through significantly larger body sizes of hybrid offspring relative to resident offspring in all recipient populations. Continued monitoring of these populations will test for negative fitness effects beyond the first generation. However, these results provide much-needed experimental data to inform the potential effectiveness of genetic rescue-motivated translocations.

  1. Implanting 8-mm passive integrated transponder tags into small Brook Trout: Effects on growth and survival in the laboratory

    Science.gov (United States)

    O'Donnell, Matthew J.; Letcher, Benjamin H.

    2017-01-01

    Passive integrated transponder (PIT) tags are commonly used to investigate relationships between individual fish and their environment. The recent availability of smaller tags has provided the opportunity to tag smaller fish. In this study, we implanted 8-mm PIT tags into small Brook Trout Salvelinus fontinalis (35–50 mm FL; 0.35–1.266 g) and compared tag retention, growth rates, and survival of PIT-tagged fish with those of fish subjected to handling only or to handling plus fin clipping. We also examined how initial size at tagging affected absolute and specific growth rates of PIT-tagged individuals over time. We found that survival was 100%, tag retention was 96.7%, and fish size did not vary across treatments at 29 and 64 d posttagging. Additionally, there was no evidence that growth rate (FL or mass) was influenced by the initial size of the fish that were PIT tagged. Our results indicate that retention rates of 8-mm PIT tags surgically implanted into small Brook Trout are high and that there is no discernible effect on growth or survival in the laboratory. The ability to implant smaller PIT tags into smaller fish earlier in the season would allow researchers conducting PIT tag studies to expand demographic models to estimate survival of age-0 fish through the summer of their first year.

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

    Science.gov (United States)

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

    2018-01-01

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

  3. Sex Chromosome Evolution, Heterochiasmy, and Physiological QTL in the Salmonid Brook Charr Salvelinus fontinalis

    Directory of Open Access Journals (Sweden)

    Ben J.G. Sutherland

    2017-08-01

    Full Text Available Whole-genome duplication (WGD can have large impacts on genome evolution, and much remains unknown about these impacts. This includes the mechanisms of coping with a duplicated sex determination system and whether this has an impact on increasing the diversity of sex determination mechanisms. Other impacts include sexual conflict, where alleles having different optimums in each sex can result in sequestration of genes into nonrecombining sex chromosomes. Sex chromosome development itself may involve sex-specific recombination rate (i.e., heterochiasmy, which is also poorly understood. The family Salmonidae is a model system for these phenomena, having undergone autotetraploidization and subsequent rediploidization in most of the genome at the base of the lineage. The salmonid master sex determining gene is known, and many species have nonhomologous sex chromosomes, putatively due to transposition of this gene. In this study, we identify the sex chromosome of Brook Charr Salvelinus fontinalis and compare sex chromosome identities across the lineage (eight species and four genera. Although nonhomology is frequent, homologous sex chromosomes and other consistencies are present in distantly related species, indicating probable convergence on specific sex and neo-sex chromosomes. We also characterize strong heterochiasmy with 2.7-fold more crossovers in maternal than paternal haplotypes with paternal crossovers biased to chromosome ends. When considering only rediploidized chromosomes, the overall heterochiasmy trend remains, although with only 1.9-fold more recombination in the female than the male. Y chromosome crossovers are restricted to a single end of the chromosome, and this chromosome contains a large interspecific inversion, although its status between males and females remains unknown. Finally, we identify quantitative trait loci (QTL for 21 unique growth, reproductive, and stress-related phenotypes to improve knowledge of the genetic

  4. Sex Chromosome Evolution, Heterochiasmy, and Physiological QTL in the Salmonid Brook CharrSalvelinus fontinalis.

    Science.gov (United States)

    Sutherland, Ben J G; Rico, Ciro; Audet, Céline; Bernatchez, Louis

    2017-08-07

    Whole-genome duplication (WGD) can have large impacts on genome evolution, and much remains unknown about these impacts. This includes the mechanisms of coping with a duplicated sex determination system and whether this has an impact on increasing the diversity of sex determination mechanisms. Other impacts include sexual conflict, where alleles having different optimums in each sex can result in sequestration of genes into nonrecombining sex chromosomes. Sex chromosome development itself may involve sex-specific recombination rate ( i.e. , heterochiasmy), which is also poorly understood. The family Salmonidae is a model system for these phenomena, having undergone autotetraploidization and subsequent rediploidization in most of the genome at the base of the lineage. The salmonid master sex determining gene is known, and many species have nonhomologous sex chromosomes, putatively due to transposition of this gene. In this study, we identify the sex chromosome of Brook Charr Salvelinus fontinalis and compare sex chromosome identities across the lineage (eight species and four genera). Although nonhomology is frequent, homologous sex chromosomes and other consistencies are present in distantly related species, indicating probable convergence on specific sex and neo-sex chromosomes. We also characterize strong heterochiasmy with 2.7-fold more crossovers in maternal than paternal haplotypes with paternal crossovers biased to chromosome ends. When considering only rediploidized chromosomes, the overall heterochiasmy trend remains, although with only 1.9-fold more recombination in the female than the male. Y chromosome crossovers are restricted to a single end of the chromosome, and this chromosome contains a large interspecific inversion, although its status between males and females remains unknown. Finally, we identify quantitative trait loci (QTL) for 21 unique growth, reproductive, and stress-related phenotypes to improve knowledge of the genetic architecture of

  5. Sex Chromosome Evolution, Heterochiasmy, and Physiological QTL in the Salmonid Brook Charr Salvelinus fontinalis

    Science.gov (United States)

    Sutherland, Ben J.G.; Rico, Ciro; Audet, Céline; Bernatchez, Louis

    2017-01-01

    Whole-genome duplication (WGD) can have large impacts on genome evolution, and much remains unknown about these impacts. This includes the mechanisms of coping with a duplicated sex determination system and whether this has an impact on increasing the diversity of sex determination mechanisms. Other impacts include sexual conflict, where alleles having different optimums in each sex can result in sequestration of genes into nonrecombining sex chromosomes. Sex chromosome development itself may involve sex-specific recombination rate (i.e., heterochiasmy), which is also poorly understood. The family Salmonidae is a model system for these phenomena, having undergone autotetraploidization and subsequent rediploidization in most of the genome at the base of the lineage. The salmonid master sex determining gene is known, and many species have nonhomologous sex chromosomes, putatively due to transposition of this gene. In this study, we identify the sex chromosome of Brook Charr Salvelinus fontinalis and compare sex chromosome identities across the lineage (eight species and four genera). Although nonhomology is frequent, homologous sex chromosomes and other consistencies are present in distantly related species, indicating probable convergence on specific sex and neo-sex chromosomes. We also characterize strong heterochiasmy with 2.7-fold more crossovers in maternal than paternal haplotypes with paternal crossovers biased to chromosome ends. When considering only rediploidized chromosomes, the overall heterochiasmy trend remains, although with only 1.9-fold more recombination in the female than the male. Y chromosome crossovers are restricted to a single end of the chromosome, and this chromosome contains a large interspecific inversion, although its status between males and females remains unknown. Finally, we identify quantitative trait loci (QTL) for 21 unique growth, reproductive, and stress-related phenotypes to improve knowledge of the genetic architecture of these

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

    Science.gov (United States)

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

    2010-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  8. Climate change and vulnerability of bull trout (Salvelinus confluentus) in a fire-prone landscape.

    Science.gov (United States)

    Falke, Jeffrey A.; Flitcroft, Rebecca L; Dunham, Jason B.; McNyset, Kristina M.; Hessburg, Paul F.; Reeves, Gordon H.

    2015-01-01

    Linked atmospheric and wildfire changes will complicate future management of native coldwater fishes in fire-prone landscapes, and new approaches to management that incorporate uncertainty are needed to address this challenge. We used a Bayesian network (BN) approach to evaluate population vulnerability of bull trout (Salvelinus confluentus) in the Wenatchee River basin, Washington, USA, under current and future climate and fire scenarios. The BN was based on modeled estimates of wildfire, water temperature, and physical habitat prior to, and following, simulated fires throughout the basin. We found that bull trout population vulnerability depended on the extent to which climate effects can be at least partially offset by managing factors such as habitat connectivity and fire size. Moreover, our analysis showed that local management can significantly reduce the vulnerability of bull trout to climate change given appropriate management actions. Tools such as our BN that explicitly integrate the linked nature of climate and wildfire, and incorporate uncertainty in both input data and vulnerability estimates, will be vital in effective future management to conserve native coldwater fishes.

  9. Using Linkage Maps as a Tool To Determine Patterns of Chromosome Synteny in the Genus Salvelinus

    Directory of Open Access Journals (Sweden)

    Matthew C. Hale

    2017-11-01

    Full Text Available Next generation sequencing techniques have revolutionized the collection of genome and transcriptome data from nonmodel organisms. This manuscript details the application of restriction site-associated DNA sequencing (RADseq to generate a marker-dense genetic map for Brook Trout (Salvelinus fontinalis. The consensus map was constructed from three full-sib families totaling 176 F1 individuals. The map consisted of 42 linkage groups with a total female map size of 2502.5 cM, and a total male map size of 1863.8 cM. Synteny was confirmed with Atlantic Salmon for 38 linkage groups, with Rainbow Trout for 37 linkage groups, Arctic Char for 36 linkage groups, and with a previously published Brook Trout linkage map for 39 linkage groups. Comparative mapping confirmed the presence of 8 metacentric and 34 acrocentric chromosomes in Brook Trout. Six metacentric chromosomes seem to be conserved with Arctic Char suggesting there have been at least two species-specific fusion and fission events within the genus Salvelinus. In addition, the sex marker (sdY; sexually dimorphic on the Y chromosome was mapped to Brook Trout BC35, which is homologous with Atlantic Salmon Ssa09qa, Rainbow Trout Omy25, and Arctic Char AC04q. Ultimately, this linkage map will be a useful resource for studies on the genome organization of Salvelinus, and facilitates comparisons of the Salvelinus genome with Salmo and Oncorhynchus.

  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, Keith H; McCormick, Stephen D

    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. Quantitative evaluation of macrophage aggregates in brook trout Salvelinus fontinalis and rainbow trout Oncorhynchus mykiss

    Science.gov (United States)

    Macrophage aggregates (MAs) occur in various organs of fishes, especially the kidney, liver and spleen, and contain melanin, ceroid/lipofuscin and hemosiderin pigments. They have been used as indicators of a number of natural and anthropogenic stressors. Macrophage aggregates occ...

  12. Epitheliocystis in lake trout Salvelinus namaycush (Walbaum) is associated with a β-proteobacteria.

    Science.gov (United States)

    Contador, E; Methner, P; Ryerse, I; Huber, P; Lillie, B N; Frasca, S; Lumsden, J S

    2016-03-01

    Lake trout Salvelinus namaycush (Walbaum) raised for stocking experienced yearly (2011-13) winter epizootics of epitheliocystis. Affected fish were dispersed on the bottom of the tank, had decreased feed and fright response, and mortality often reached 40%. Peak mortality occurred within 3 weeks of the appearance of clinical signs, and outbreaks typically lasted 6 weeks. Affected fish had no gross lesions but histologically had branchial epithelial necrosis and lamellar hyperplasia, with small to large numbers of scattered epithelial cells containing 10- to 20-μm inclusions. A longitudinal study was undertaken of one annual outbreak, and lamellar hyperplasia was most closely associated with mortality. The number of inclusions was statistically greater (P < 0.05) before and during peak mortality, but inclusions were present in low numbers before clinical signs occurred. Results of histochemical staining, immunohistochemistry and transmission electron microscopy supported the presence of a β-proteobacteria rather than a Chlamydiales bacterium within inclusions. PCR primers to identify Chlamydiales did not give consistent results. However, the use of universal 16S rDNA bacterial primers in conjunction with laser capture microdissection of inclusions demonstrated that a β-proteobacteria was consistently associated with affected gills and is more likely the cause of the disease in lake trout. © 2015 John Wiley & Sons Ltd.

  13. 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.

  14. New insight into the spawning behavior of lake trout, Salvelinus namaycush, from a recovering population in the Laurentian Great Lakes

    Science.gov (United States)

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

    2015-01-01

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

  15. Bull trout (Salvelinus confluentus) telemetry and associated habitat data collected in a geodatabase from the upper Boise River, southwestern Idaho

    Science.gov (United States)

    MacCoy, Dorene E.; Shephard, Zachary M.; Benjamin, Joseph R.; Vidergar, Dmitri T.; Prisciandaro, Anthony F.

    2017-03-23

    Bull trout (Salvelinus confluentus), listed as threatened under the Endangered Species Act, are among the more thermally sensitive of coldwater species in North America. The Boise River upstream of Arrowrock Dam in southwestern Idaho (including Arrowrock Reservoir) provides habitat for one of the southernmost populations of bull trout. The presence of the species in Arrowrock Reservoir poses implications for dam and reservoir operations. From 2011 to 2014, the Bureau of Reclamation and the U.S. Geological Survey collected fish telemetry data to improve understanding of bull trout distribution and movement in Arrowrock Reservoir and in the upper Boise River tributaries. The U.S. Geological Survey compiled the telemetry (fish location) data, along with reservoir elevation, river discharge, precipitation, and water-quality data in a geodatabase. The geodatabase includes metadata compliant with Federal Geographic Data Committee content standards. The Bureau of Reclamation plans to incorporate the data in a decision‑support tool for reservoir management.

  16. 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.

  17. 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

  18. Divergence in physiological factors affecting swimming performance between anadromous and resident populations of brook charr Salvelinus fontinalis.

    Science.gov (United States)

    Crespel, A; Dupont-Prinet, A; Bernatchez, L; Claireaux, G; Tremblay, R; Audet, C

    2017-05-01

    In this study, an anadromous strain (L) and a freshwater-resident (R) strain of brook charr Salvelinus fontinalis as well as their reciprocal hybrids, were reared in a common environment and submitted to swimming tests combined with salinity challenges. The critical swimming speeds (Ucrit ) of the different crosses were measured in both fresh (FW) and salt water (SW) and the variations in several physiological traits (osmotic, energetic and metabolic capacities) that are predicted to influence swimming performance were documented. Anadromous and resident fish reached the same Ucrit in both FW and SW, with Ucrit being 14% lower in SW compared with FW. The strains, however, seemed to use different underlying strategies: the anadromous strain relied on its streamlined body shape and higher osmoregulatory capacity, while the resident strain had greater citrate synthase (FW) and lactate dehydrogenase (FW, SW) capacity and either greater initial stores or more efficient use of liver (FW, SW) and muscle (FW) glycogen during exercise. Compared with R♀ L♂ hybrids, L♀ R♂ hybrids had a 20% lower swimming speed, which was associated with a 24% smaller cardio-somatic index and higher physiological costs. Thus swimming performance depends on cross direction (i.e. which parental line was used as dam or sire). The study thus suggests that divergent physiological factors between anadromous and resident S. fontinalis may result in similar swimming capacities that are adapted to their respective lifestyles. © 2017 The Fisheries Society of the British Isles.

  19. Seasonal habitat selection by lake trout (Salvelinus namaycush) in a small Canadian shield lake: Constraints imposed by winter conditions

    Science.gov (United States)

    Blanchfield, P.J.; Tate, L.S.; Plumb, J.M.; Acolas, M.-L.; Beaty, K.G.

    2009-01-01

    The need for cold, well-oxygenated waters significantly reduces the habitat available for lake trout (Salvelinus namaycush) during stratification of small temperate lakes. We examined the spatial and pelagic distribution of lake trout over two consecutive summers and winters and tested whether winter increased habitat availability and access to littoral regions in a boreal shield lake in which pelagic prey fish are absent. In winter, lake trout had a narrowly defined pelagic distribution that was skewed to the upper 3 m of the water column and spatially situated in the central region of the lake. Individual core areas of use (50% Kernel utilization distributions) in winter were much reduced (75%) and spatially non-overlapping compared to summer areas, but activity levels were similar between seasons. Winter habitat selection is in contrast to observations from the stratified season, when lake trout were consistently located in much deeper waters (>6 m) and widely distributed throughout the lake. Winter distribution of lake trout appeared to be strongly influenced by ambient light levels; snow depth and day length accounted for up to 69% of the variation in daily median fish depth. More restricted habitat use during winter than summer was in contrast to our original prediction and illustrates that a different suite of factors influence lake trout distribution between these seasons. ?? Springer Science+Business Media B.V. 2009.

  20. Foraging mechanisms of siscowet lake trout (Salvelinus namaycush siscowet) on pelagic prey

    Science.gov (United States)

    Keyler, Trevor D.; Hrabik, Thomas R.; Austin, C. Lee; Gorman, Owen T.; Mensinger, Allen F.

    2015-01-01

    The reaction distance, angle of attack, and foraging success were determined for siscowet lake trout (Salvelinus namaycush siscowet) during laboratory trials under lighting conditions that approximated downwelling spectral irradiance and intensity (9.00 × 108–1.06 × 1014 photons m− 2 s− 1) at daytime depths. Siscowet reaction distance in response to golden shiners (Notemigonus crysoleucas) was directly correlated with increasing light intensity until saturation at 1.86 × 1011 photons m− 2 s− 1, above which reaction distance was constant within the range of tested light intensities. At the lowest tested light intensity, sensory detection was sufficient to locate prey at 25 ± 2 cm, while increasing light intensities increased reaction distance up to 59 ± 2 cm at 1.06 × 1014 photons m− 2 s− 1. Larger prey elicited higher reaction distances than smaller prey at all light intensities while moving prey elicited higher reaction distances than stationary prey at the higher light intensities (6.00 × 109 to 1.06 × 1014 photons m− 2 s− 1). The capture and consumption of prey similarly increased with increasing light intensity while time to capture decreased with increasing light intensity. The majority of orientations toward prey occurred within 120° of the longitudinal axis of the siscowet's eyes, although reaction distances among 30° increments along the entire axis were not significantly different. The developed predictive model will help determine reaction distances for siscowet in various photic environments and will help identify the mechanisms and behavior that allow for low light intensity foraging within freshwater systems.

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

    Science.gov (United States)

    Maret, Terry R.; Schultz, Justin E.

    2013-01-01

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

  2. Thermal regimes, nonnative trout, and their influences on native Bull Trout in the Upper Klamath River Basin, Oregon

    Science.gov (United States)

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

    2016-01-01

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

  3. Displacement of native white-spotted charr Salvelinus leucomaenis by non-native brown trout Salmo trutta after resolution of habitat fragmentation by a migration barrier.

    Science.gov (United States)

    Hasegawa, K

    2017-06-01

    After resolution of habitat fragmentation by an erosion-control dam, non-native brown trout Salmo trutta invaded the upstream side of the dam and displaced native white-spotted charr Salvelinus leucomaenis in Monbetsu stream, Hokkaido, northern Japan. © 2017 The Fisheries Society of the British Isles.

  4. Sampling large geographic areas for rare species using environmental DNA: A study of bull trout Salvelinus confluentus occupancy in western Montana

    Science.gov (United States)

    Kevin McKelvey; Michael Young; W. L. Knotek; K. J. Carim; T. M. Wilcox; T. M. Padgett-Stewart; Michael Schwartz

    2016-01-01

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

  5. PCB concentrations in lake trout (Salvelinus namaycush) are correlated to habitat use and lake characteristics.

    Science.gov (United States)

    Guildford, S J; Muir, D C G; Houde, M; Evans, M S; Kidd, K A; Whittle, D M; Drouillard, K; Wang, X; Anderson, M R; Bronte, C R; Devault, D S; Haffner, D; Payne, J; Kling, H J

    2008-11-15

    This study considers the importance of lake trout habitat as a factor determining persistent organochlorine (OC) concentration. Lake trout is a stenothermal, cold water species and sensitive to hypoxia. Thus, factors such as lake depth, thermal stratification, and phosphorus enrichment may determine not only which lakes can support lake trout but may also influence among-lake variability in lake trout population characteristics including bioaccumulation of OCs. A survey of 23 lakes spanning much of the natural latitudinal distribution of lake trout provided a range of lake trout habitat to test the hypothesis that lake trout with greater access to littoral habitat for feeding will have lower concentrations of OCs than lake trout that are more restricted to pelagic habitat. Using the delta13C stable isotope signature in lake trout as an indicator of influence of benthic littoral feeding, we found a negative correlation between lipid-corrected delta13C and sigmaPCB concentrations supporting the hypothesis that increasing accessto littoral habitat results in lower OCs in lake trout. The prominence of mixotrophic phytoplankton in lakes with more contaminated lake trout indicated the pelagic microbial food web may exacerbate the biomagnification of OCs when lake trout are restricted to pelagic feeding. A model that predicted sigmaPCB in lake trout based on lake area and latitude (used as proximate variables for proportion of littoral versus pelagic habitat and accessibility to littoral habitat respectively) explained 73% of the variability in sigmaPCBs in lake trout in the 23 lakes surveyed.

  6. 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.

  7. Fine-scale acoustic telemetry reveals unexpected lake trout, Salvelinus namaycush, spawning habitats in northern Lake Huron, North America

    Science.gov (United States)

    Binder, Thomas; Farha, Steve A.; Thompson, Henry T.; Holbrook, Christopher; Bergstedt, Roger A.; Riley, Stephen; Bronte, Charles R.; He, Ji; Krueger, Charles C.

    2017-01-01

    Previous studies of lake trout, Salvelinus namaycush, spawning habitat in the Laurentian Great Lakes have used time- and labour-intensive survey methods and have focused on areas with historic observations of spawning aggregations and on habitats prejudged by researchers to be suitable for spawning. As an alternative, we used fine-scale acoustic telemetry to locate, describe and compare lake trout spawning habitats. Adult lake trout were implanted with acoustic transmitters and tracked during five consecutive spawning seasons in a 19–27 km2 region of the Drummond Island Refuge, Lake Huron, using the VEMCO Positioning System. Acoustic telemetry revealed discrete areas of aggregation on at least five reefs in the study area, subsequently confirmed by divers to contain deposited eggs. Notably, several identified spawning sites would likely not have been discovered using traditional methods because either they were too small and obscure to stand out on a bathymetric map or because they did not conform to the conceptual model of spawning habitat held by many biologists. Our most unique observation was egg deposition in gravel and rubble substrates located at the base of and beneath overhanging edges of large boulders. Spawning sites typically comprised acoustic transmitters offers potential to expand current conceptual models of critical spawning habitat.

  8. 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...

  9. Alien invasions in aquatic ecosystems: toward an understanding of brook trout invasions and potential impacts on inland cutthroat trout in western North America

    Science.gov (United States)

    Jason B. Dunham; Susan B. Adams; Robert E. Schroeter; Douglas C. Novinger

    2002-01-01

    Experience from case studies of biological invasions in aquatic ecosystems has motivated a set of proposed empirical “rules” for understanding patterns of invasion and impacts on native species. Further evidence is needed to better understand these patterns, and perhaps contribute to a useful predictive theory of invasions. We reviewed the case of brook trout (

  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. Physiological and biochemical responses of rainbow trout and brook trout exposed to elevated selenium from coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Miller, L.; Rasmussen, J.; Hontela, A. [Lethbridge Univ., Lethbridge, AB (Canada); Palace, V.; Carroll, L. [Fisheries and Oceans Canada, Winnipeg, MB (Canada); Wang, F. [Manitoba Univ., Winnipeg, MB (Canada)

    2009-07-01

    Since selenium (Se) is an element that bioaccumulates, anthropogenic activities in areas that already have high Se in parent rock can result in an increase in Se in aquatic systems. Se causes reproductive deformities in rainbow trout (RT), at lower concentrations than for brook trout (BT). This presentation reported on a study conducted at coal mines in northeastern Alberta in which juvenile hatchery-reared RT and BT were stocked into 2 reference and 2 Se contaminated end pit lakes. Fish were sampled at 0, 6, and 12 months after stocking, and will be sampled at 18 and 24 months. Water Se levels were found to be high in contaminated lakes. Selenite, the more toxic form of Se, was the highest in Pit C4. Liver glutathione levels were similar in the 2 fish species, and cellular damage in the fish was beginning to increase. At 6 months, liver glycogen levels were higher in the BT than in the RT, but no tangible site specific patterns emerged. At all sites except Pit C4, the RT were in better condition than BT. BT from Pit C4 also had a lower ability to secrete cortisol, suggesting that the elevated selenite levels may negatively affect fish. Se accumulation results from 28 fish sampled at 12 months were also discussed.

  12. 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.

  13. Epizootic neoplasia of the lateral line system of lake trout (Salvelinus namaycush) in New York's Finger Lakes.

    Science.gov (United States)

    Spitsbergen, J M; Frattini, S A; Bowser, P R; Getchell, R G; Coffee, L L; Wolfe, M J; Fisher, J P; Marinovic, S J; Harr, K E

    2013-05-01

    This article documents an epizootic of inflammation and neoplasia selectively affecting the lateral line system of lake trout (Salvelinus namaycush) in 4 Finger Lakes in New York from 1985 to 1994. We studied more than 100 cases of this disease. Tumors occurred in 8% (5/64) of mature and 21% (3/14) of immature lake trout in the most severely affected lake. Lesions consisted of 1 or more neoplasm(s) in association with lymphocytic inflammation, multifocal erosions, and ulcerations of the epidermis along the lateral line. Lesions progressed from inflammatory to neoplastic, with 2-year-old lake trout showing locally extensive, intense lymphocytic infiltrates; 2- to 3-year-old fish having multiple, variably sized white masses up to 3 mm in diameter; and fish over 5 years old exhibiting 1 or more white, cerebriform masses greater than 1 cm in diameter. Histologic diagnoses of the tumors were predominantly spindle cell sarcomas or benign or malignant peripheral nerve sheath neoplasms, with fewer epitheliomas and carcinomas. Prevalence estimates did not vary significantly between sexes or season. The cause of this epizootic remains unclear. Tumor transmission trials, virus isolation procedures, and ultrastructural study of lesions failed to reveal evidence of a viral etiology. The Finger Lakes in which the disease occurred did not receive substantially more chemical pollution than unaffected lakes in the same chain during the epizootic, making an environmental carcinogen an unlikely primary cause of the epizootic. A hereditary component, however, may have contributed to this syndrome since only fish of the Seneca Lake strain were affected.

  14. 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.

  15. Movement patterns and spatial segregation of two populations of lake trout Salvelinus namaycush in Lake Huron

    Science.gov (United States)

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

    2017-01-01

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

  16. 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.

  17. Can personality predict individual differences in brook trout spatial learning ability?

    Science.gov (United States)

    White, S L; Wagner, T; Gowan, C; Braithwaite, V A

    2017-08-01

    While differences in individual personality are common in animal populations, understanding the ecological significance of variation has not yet been resolved. Evidence suggests that personality may influence learning and memory; a finding that could improve our understanding of the evolutionary processes that produce and maintain intraspecific behavioural heterogeneity. Here, we tested whether boldness, the most studied personality trait in fish, could predict learning ability in brook trout. After quantifying boldness, fish were trained to find a hidden food patch in a maze environment. Stable landmark cues were provided to indicate the location of food and, at the conclusion of training, cues were rearranged to test for learning. There was a negative relationship between boldness and learning as shy fish were increasingly more successful at navigating the maze and locating food during training trials compared to bold fish. In the altered testing environment, only shy fish continued using cues to search for food. Overall, the learning rate of bold fish was found to be lower than that of shy fish for several metrics suggesting that personality could have widespread effects on behaviour. Because learning can increase plasticity to environmental change, these results have significant implications for fish conservation. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Can personality predict individual differences in brook trout spatial learning ability?

    Science.gov (United States)

    White, S.L.; Wagner, Tyler; Gowan, C.; Braithwaite, V.A.

    2017-01-01

    While differences in individual personality are common in animal populations, understanding the ecological significance of variation has not yet been resolved. Evidence suggests that personality may influence learning and memory; a finding that could improve our understanding of the evolutionary processes that produce and maintain intraspecific behavioural heterogeneity. Here, we tested whether boldness, the most studied personality trait in fish, could predict learning ability in brook trout. After quantifying boldness, fish were trained to find a hidden food patch in a maze environment. Stable landmark cues were provided to indicate the location of food and, at the conclusion of training, cues were rearranged to test for learning. There was a negative relationship between boldness and learning as shy fish were increasingly more successful at navigating the maze and locating food during training trials compared to bold fish. In the altered testing environment, only shy fish continued using cues to search for food. Overall, the learning rate of bold fish was found to be lower than that of shy fish for several metrics suggesting that personality could have widespread effects on behaviour. Because learning can increase plasticity to environmental change, these results have significant implications for fish conservation.

  19. Effects of dietary excesses of branched-chain amino acids on the metabolism and tissue composition of lake trout (Salvelinus namaycush)

    Science.gov (United States)

    Hughes, S.G.; Rumsey, G.L.; Nesheim, M.C.

    1984-01-01

    1. Excesses of either leucine, isoleucine or valine were fed in separate experiments to determine if the branched-chain amino acid antagonism reported in other animals occur in trout (Salvelinus namaycush).2. Parameters measured include growth rate, feed utilization efficiency, plasma and muscle-free amino acids, carcass composition and branched-chain amino acid aminotransferase.3. Dietary excesses of leucine or isoleucine caused an increase in the valine requirement.4. The inability of leucine and isoleucine supplementations to ameliorate the effects of excess dietary valine are interpreted as a valine toxicity rather than an antagonism.

  20. Sampling large geographic areas for rare species using environmental DNA: a study of bull trout Salvelinus confluentus occupancy in western Montana.

    Science.gov (United States)

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

    2016-03-01

    This study tested the efficacy of environmental DNA (eDNA) sampling to delineate the distribution of bull trout Salvelinus confluentus in headwater streams in western Montana, U.S.A. Surveys proved fast, reliable and sensitive: 124 samples were collected across five basins by a single crew in c. 8 days. Results were largely consistent with past electrofishing, but, in a basin where S. confluentus were known to be scarce, eDNA samples indicated that S. confluentus were more broadly distributed than previously thought. © 2016 The Fisheries Society of the British Isles.

  1. Inter-relationships between the spawning migration of Eagle Lake rainbow trout, streamflow, snowpack, and air temperature

    OpenAIRE

    Thompson, Lisa C.

    2009-01-01

    Pine Creek has historically provided critical spawning and rearing habitat for Eagle Lake rainbow trout (ELRT, Oncorhynchus mykiss aquilarum). Over the past 100+ years modifications of Pine Creek watershed (e.g., overgrazing, timber harvest, passage barriers, culverts) decoupled the ELRT from its stream habitat. Introduced brook trout (Salvelinus fontinalis) now dominate historic rearing areas in the upper watershed. Passage barriers were constructed on Eagle Lake tributaries to prevent ELRT ...

  2. Analysis of brook trout spatial behavior during passage attempts in corrugated culverts using near-infrared illumination video imagery

    Science.gov (United States)

    Bergeron, Normand E.; Constantin, Pierre-Marc; Goerig, Elsa; Castro-Santos, Theodore R.

    2016-01-01

    We used video recording and near-infrared illumination to document the spatial behavior of brook trout of various sizes attempting to pass corrugated culverts under different hydraulic conditions. Semi-automated image analysis was used to digitize fish position at high temporal resolution inside the culvert, which allowed calculation of various spatial behavior metrics, including instantaneous ground and swimming speed, path complexity, distance from side walls, velocity preference ratio (mean velocity at fish lateral position/mean crosssectional velocity) as well as number and duration of stops in forward progression. The presentation summarizes the main results and discusses how they could be used to improve fish passage performance in culverts.

  3. Geomorphic, flood, and groundwater-flow characteristics of Bayfield Peninsula streams, Wisconsin, and implications for brook-trout habitat

    Science.gov (United States)

    Fitzpatrick, Faith A.; Peppler, Marie C.; Saad, David A.; Pratt, Dennis M.; Lenz, Bernard N.

    2015-01-01

    In 2002–03, the U.S. Geological Survey conducted a study of the geomorphic, flood, and groundwater-flow characteristics of five Bayfield Peninsula streams, Wisconsin (Cranberry River, Bark River, Raspberry River, Sioux River, and Whittlesey Creek) to determine the physical limitations for brook-trout habitat. The goals of the study were threefold: (1) to describe geomorphic characteristics and processes, (2) to determine how land-cover characteristics affect flood peaks, and (3) to determine how regional groundwater flow patterns affect base flow.

  4. Spatial and temporal distribution of bull trout (Salvelinus confluentus)-size fish near the floating surface collector in the North Fork Reservoir, Oregon, 2016

    Science.gov (United States)

    Adams, Noah S.; Smith, Collin D.

    2017-06-26

    Acoustic cameras were used to assess the behavior and abundance of bull trout (Salvelinus confluentus)-size fish at the entrance to the North Fork Reservoir juvenile fish floating surface collector (FSC). The purpose of the FSC is to collect downriver migrating juvenile salmonids at the North Fork Dam, and safely route them around the hydroelectric projects. The objective of the acoustic camera component of this study was to assess the behaviors of bull trout-size fish observed near the FSC, and to determine if the presence of bull trout-size fish influenced the collection or abundance of juvenile salmonids. Acoustic cameras were deployed near the surface and floor of the entrance to the FSC. The acoustic camera technology was an informative tool for assessing abundance and spatial and temporal behaviors of bull trout-size fish near the entrance of the FSC. Bull trout-size fish were regularly observed near the entrance, with greater abundances on the deep camera than on the shallow camera. Additionally, greater abundances were observed during the hours of sunlight than were observed during the night. Behavioral differences also were observed at the two depths, with surface fish traveling faster and straighter with more directed movement, and fish observed on the deep camera generally showing more milling behavior. Modeling potential predator-prey interactions and influences using collected passive integrated transponder (PIT) -tagged juvenile salmonids proved largely unpredictable, although these fish provided relevant timing and collection information. Overall, the results indicate that bull trout-size fish are present near the entrance of the FSC, concomitant with juvenile salmonids, and their abundances and behaviors indicate that they may be drawn to the entrance of the FSC because of the abundance of prey-sized fish.

  5. Population response to habitat fragmentation in a stream-dwelling brook trout population.

    Directory of Open Access Journals (Sweden)

    Benjamin H Letcher

    Full Text Available Fragmentation can strongly influence population persistence and expression of life-history strategies in spatially-structured populations. In this study, we directly estimated size-specific dispersal, growth, and survival of stream-dwelling brook trout in a stream network with connected and naturally-isolated tributaries. We used multiple-generation, individual-based data to develop and parameterize a size-class and location-based population projection model, allowing us to test effects of fragmentation on population dynamics at local (i.e., subpopulation and system-wide (i.e., metapopulation scales, and to identify demographic rates which influence the persistence of isolated and fragmented populations. In the naturally-isolated tributary, persistence was associated with higher early juvenile survival ( approximately 45% greater, shorter generation time (one-half and strong selection against large body size compared to the open system, resulting in a stage-distribution skewed towards younger, smaller fish. Simulating barriers to upstream migration into two currently-connected tributary populations caused rapid (2-6 generations local extinction. These local extinctions in turn increased the likelihood of system-wide extinction, as tributaries could no longer function as population sources. Extinction could be prevented in the open system if sufficient immigrants from downstream areas were available, but the influx of individuals necessary to counteract fragmentation effects was high (7-46% of the total population annually. In the absence of sufficient immigration, a demographic change (higher early survival characteristic of the isolated tributary was also sufficient to rescue the population from fragmentation, suggesting that the observed differences in size distributions between the naturally-isolated and open system may reflect an evolutionary response to isolation. Combined with strong genetic divergence between the isolated tributary and

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

    Science.gov (United States)

    Eby, Lisa A; Helmy, Olga; Holsinger, Lisa M; Young, Michael K

    2014-01-01

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

  7. 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, Nathan B.; Hinch, Scott G.; Lotto, A.G.; Beauchamp, David 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.

  8. Evaluation of glutamic acid and glycine as sources of nonessential amino acids for lake trout (Salvelinus namaycush) and rainbow trout (Salmo gairdnerii)

    Science.gov (United States)

    Hughes, S.G.

    1985-01-01

    1. A semi-purified test diet which contained either glutamic acid or glycine as the major source of nonessential amino acids (NEAA) was fed to lake and rainbow trout.2. Trout fed the diet containing glutamic acid consistently showed better growth and feed conversion efficiencies than those fed the diets containing glycine.3. The data indicate that these trout utilize glutamic acid more efficiently than glycine when no other major sources of NEAA are present.

  9. A Bayesian assessment of the mercury and PCB temporal trends in lake trout (Salvelinus namaycush) and walleye (Sander vitreus) from lake Ontario, Ontario, Canada.

    Science.gov (United States)

    Visha, Ariola; Gandhi, Nilima; Bhavsar, Satyendra P; Arhonditsis, George B

    2015-07-01

    Polychlorinated biphenyls (PCBs) and total mercury (THg) are two of the most prevalent contaminants, resulting in restrictive advisories on consuming fish from the Laurentian Great Lakes. The goal of this study is to examine the temporal trends of the two contaminants in walleye (Sander vitreus) and lake trout (Salvelinus namaycush) for Lake Ontario. We employed Bayesian inference techniques to parameterize three different strategies of time series analysis: dynamic linear, exponential decay, and mixed-order modeling. Our analysis sheds light on the role of different covariates (length, lipid content) that can potentially hamper the detection of the actual temporal patterns of fish contaminants. Both PCBs and mercury demonstrate decreasing temporal trends in lake trout males and females. Decreasing PCB trends are evident in walleye, but the mean annual mercury levels are characterized by a "wax and wane" pattern, suggesting that specific fish species may not act as bio-indicators for all contaminants. This finding may be attributed to the shifts in energy trophodynamics along with the food web alterations induced from the introduction of non-native species, the intricate nature of the prey-predator interactions, the periodicities of climate factors, and the year-to-year variability of the potentially significant fluxes from atmosphere or sediments. Finally, a meaningful risk assessment exercise will be to elucidate the role of within-lake fish contaminant variability and evaluate the potential bias introduced when drawing inference from pooled datasets. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Direct and indirect climatic drivers of biotic interactions: ice-cover and carbon runoff shaping Arctic char Salvelinus alpinus and brown trout Salmo trutta competitive asymmetries.

    Science.gov (United States)

    Ulvan, Eva M; Finstad, Anders G; Ugedal, Ola; Berg, Ole Kristian

    2012-01-01

    One of the major challenges in ecological climate change impact science is to untangle the climatic effects on biological interactions and indirect cascading effects through different ecosystems. Here, we test for direct and indirect climatic drivers on competitive impact of Arctic char (Salvelinus alpinus L.) on brown trout (Salmo trutta L.) along a climate gradient in central Scandinavia, spanning from coastal to high-alpine environments. As a measure of competitive impact, trout food consumption was measured using (137)Cs tracer methodology both during the ice-covered and ice-free periods, and contrasted between lakes with or without char coexistence along the climate gradient. Variation in food consumption between lakes was best described by a linear mixed effect model including a three-way interaction between the presence/absence of Arctic char, season and Secchi depth. The latter is proxy for terrestrial dissolved organic carbon run-off, strongly governed by climatic properties of the catchment. The presence of Arctic char had a negative impact on trout food consumption. However, this effect was stronger during ice-cover and in lakes receiving high carbon load from the catchment, whereas no effect of water temperature was evident. In conclusion, the length of the ice-covered period and the export of allochthonous material from the catchment are likely major, but contrasting, climatic drivers of the competitive interaction between two freshwater lake top predators. While future climatic scenarios predict shorter ice-cover duration, they also predict increased carbon run-off. The present study therefore emphasizes the complexity of cascading ecosystem effects in future effects of climate change on freshwater ecosystems.

  11. The evolutionary consequences of habitat fragmentation: Body morphology and coloration differentiation among brook trout populations of varying size.

    Science.gov (United States)

    Zastavniouk, Carol; Weir, Laura K; Fraser, Dylan J

    2017-09-01

    A reduction in population size due to habitat fragmentation can alter the relative roles of different evolutionary mechanisms in phenotypic trait differentiation. While deterministic (selection) and stochastic (genetic drift) mechanisms are expected to affect trait evolution, genetic drift may be more important than selection in small populations. We examined relationships between mature adult traits and ecological (abiotic and biotic) variables among 14 populations of brook trout. These naturally fragmented populations have shared ancestry but currently exhibit considerable variability in habitat characteristics and population size (49 habitat variation or operational sex ratio than to population size, suggesting that selection may overcome genetic drift at small population size. Phenotype-environment associations were also stronger in females than males, suggesting that natural selection due to abiotic conditions may act more strongly on females than males. Our results suggest that natural and sexual-selective pressures on phenotypic traits change during the process of habitat fragmentation, and that these changes are largely contingent upon existing habitat conditions within isolated fragments. Our study provides an improved understanding of the ecological and evolutionary consequences of habitat fragmentation and lends insight into the ability of some small populations to respond to selection and environmental change.

  12. Agonistic behavior among three stocked trout species in a novel reservoir fish community

    Science.gov (United States)

    Budy, Phaedra; Hafen, Konrad

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Kidd, Karen A., E-mail: 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

  14. Bull Trout Population Assessment in the Columbia River Gorge : Annual Report 2000.

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, Jim; McPeak, Ron

    2001-02-01

    We summarized existing knowledge regarding the known distribution of bull trout (Salvelinus confluentus) across four sub-basins in the Columbia River Gorge in Washington. The Wind River, Little White Salmon River, White Salmon River, and the Klickitat River sub-basins were analyzed. Cold water is essential to the survival, spawning, and rearing of bull trout. We analyzed existing temperature data, installed Onset temperature loggers in the areas of the four sub-basins where data was not available, and determined that mean daily water temperatures were <15 C and appropriate for spawning and rearing of bull trout. We snorkel surveyed more than 74 km (46.25 mi.) of rivers and streams in the four sub-basins (13.8 km at night and 60.2 km during the day) and found that night snorkeling was superior to day snorkeling for locating bull trout. Surveys incorporated the Draft Interim Protocol for Determining Bull Trout Presence (Peterson et al. In Press). However, due to access and safety issues, we were unable to randomly select sample sites nor use block nets as recommended. Additionally, we also implemented the Bull Trout/Dolly Varden sampling methodology described in Bonar et al. (1997). No bull trout were found in the Wind River, Little White Salmon, or White Salmon River sub-basins. We found bull trout in the West Fork Klickitat drainage of the Klickitat River Sub-basin. Bull trout averaged 6.7 fish/100m{sup 2} in Trappers Creek, 2.6 fish/100m{sup 2} on Clearwater Creek, and 0.4 fish/100m{sup 2} in Little Muddy Creek. Bull trout was the only species of salmonid encountered in Trappers Creek and dominated in Clearwater Creek. Little Muddy Creek was the only creek where bull trout and introduced brook trout occurred together. We found bull trout only at night and typically in low flow regimes. A single fish, believed to be a bull trout x brook trout hybrid, was observed in the Little Muddy Creek. Additional surveys are needed in the West Fork Klickitat and mainstem

  15. Understanding environmental DNA detection probabilities: A case study using a stream-dwelling char Salvelinus fontinalis

    Science.gov (United States)

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

    2016-01-01

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

  16. 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

    2016-01-01

    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.

  17. 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)

    National Research Council Canada - National Science Library

    Norman, Joseph D; Robinson, Mike; Glebe, Brian; Ferguson, Moira M; Danzmann, Roy G

    2012-01-01

    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...

  18. Stable isotope evaluation of population- and individual-level diet variability in a large, oligotrophic lake with non-native lake trout

    Science.gov (United States)

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

    2016-01-01

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

  19. Pathogens associated with native and exotic trout populations in Shenandoah National Park and the relationships to fish stocking practices

    Science.gov (United States)

    Panek, Frank M.; Atkinson, James; Coll, John

    2008-01-01

    Restrictive fish stocking policies in National Parks were developed as early as 1936 in order to preserve native fish assemblages and historic genetic diversity. Despite recent efforts to understand the effects of non-native or exotic fish introductions, park managers have limited information regarding the effects of these introductions on native fish communities. Shenandoah National Park was established in 1936 and brook trout (Salvelinus fontinalis) restoration within selected streams in the park began in 1937 in collaboration with the Virginia Department of Game and Inland Fisheries (VDGIF). An analysis of tissue samples from brook, brown (Salmo trutta), and rainbow trout (Oncorhynchus mykiss) from 29 streams within the park from 1998–2002 revealed the presence of Renibacterium salmoninarum, Yersinia ruckeri, and infectious pancreatic necrosis virus (IPNv). In order to investigate the relationships of the occurrence of fish pathogens with stocking histories we classified the streams into three categories: 1) streams with no record of stocking, 2) streams that are known to have been stocked historically, and 3) streams that were historically stocked within the park and continue to be stocked downstream of the park boundary. The occurrences of pathogens were summarized relative to this stocking history. Renibacterium salmoninarum, the causative agent of bacterial kidney disease, was the most prevalent pathogen found, occurring in all three species and stream stocking categories, and appears to be endemic to the park. Two other pathogens, Yersinia ruckeri and infectious pancreatic necrosis virus were also described from brook trout populations within the park. IPNv was only found in brook trout populations in streams with prior stocking histories. Yersinia ruckeri was only found in brook trout in steams that have never been stocked and like R. salmoninarum, is likely endemic.

  20. 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...

  1. 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.

  2. Effects of dietary vitamin B₁ (thiamine) and magnesium on the survival, growth and histological indicators in lake trout (Salvelinus namaycush) juveniles.

    Science.gov (United States)

    Lee, Bong-Joo; Jaroszewska, Marta; Dabrowski, Konrad; Czesny, Sergiusz; Rinchard, Jacques

    2012-07-01

    An interaction of two essential nutrients, thiamine and magnesium (Mg) has been documented in in vitro and in vivo studies in mammalian metabolism. However, the role of this association in poikilothermic vertebrates, such as fish, remains elusive. The purpose of this study was first to investigate the effects of dietary thiamine and Mg, and their interaction in lake trout and second to better understand the mechanism leading to early mortality syndrome (EMS), which is caused by a low thiamine level in embryos of many species of salmonids in the wild. Semi-purified diets (SPD) were prepared to accomplish 2 × 2 factorial design that were either devoid of or supplemented with thiamine mononitrate (20 mg/kg diet), magnesium oxide (700 mg/kg diet), or both. Lake trout alevins at the swim-up stage were fed for 10 wk one of the SPD diets or a commercial diet at the same rate (2.0-1.5%) based on recorded biomass. Our results showed that the concentrations of thiamine in the trunk muscle and Mg of whole body were closely associated with the dietary level of two nutrients. The interaction of low dietary Mg and thiamine resulted in apparently worsened overt symptoms of thiamine deficiency in lake trout leading to a higher mortality of fish during the seven week long trial (P<0.05). The fish fed a thiamine-devoid and Mg-supplemented diet were presumed to survive longer (10 wk) than the fish fed diets devoid of both nutrients (discontinued after 7th wk due to high mortality). However, we did not observe histopathological changes in the brain and liver corresponding to thiamine concentrations in tissues. These data suggest that Mg enhanced utilization of the thiamine remaining in the fish body and its interdependence was consistent with observations in mammals. EMS severity might be worsened when Mg is deficient in parental diets (and consequently in yolk sac) and/or first feed. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Retinoid metabolism in lake trout (Salvelinus namaycush) orally exposed to 3,3{prime},4,4{prime},5-pentalchlorobiphenyl (PCB 126)

    Energy Technology Data Exchange (ETDEWEB)

    Palace, V.P. [Univ. of Manitoba, Winnipeg, Manitoba (Canada); Klaverkamp, J.F.; Baron, C.L.; Brown, S.B. [Department of Fisheries and Oceans, Winnipeg, Manitoba (Canada)

    1995-12-31

    Juvenile lake trout were orally exposed to 0, 3, 10 or 30 {micro}g PCB 126 kg{sup {minus}1} bodyweight for 12 weeks. Catheters were then inserted to the dorsal aorta and {sup 3}H-retinol was injected as a bolus in charcoal stripped plasma through the catheter. Blood samples were obtained 15 and 30 minutes and 1, 3, 6, 15, 30, 50 and 75 hours after the injection. The plasma recovery profiles were compared for each PCB dose group and were not significantly different for any of the treatments. However, bile radioactivity indicates accelerated metabolism of{sup 3}H-retinol with increasing PCB dose. Tissue distributions of retinol and retinol metabolites will be described. These measures, in addition to the mixed-function oxidase and conjugating enzyme activities allow an assessment of possible mechanisms for depletion of retinoid stores in PCB exposed fish.

  4. 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.

  5. Earning their stripes: The potential of tiger trout and other salmonids as biological controls of forage fishes in a western reservoir

    Science.gov (United States)

    Winters, Lisa K.; Budy, Phaedra; Thiede, Gary P.

    2017-01-01

    Maintaining a balance between predator and prey populations can be an ongoing challenge for fisheries managers, especially in managing artificial ecosystems such as reservoirs. In a high-elevation Utah reservoir, the unintentional introduction of the Utah Chub Gila atraria and its subsequent population expansion prompted managers to experimentally shift from exclusively stocking Rainbow Trout Oncorhynchus mykiss to also stocking tiger trout (female Brown Trout Salmo trutta × male Brook Trout Salvelinus fontinalis) and Bonneville Cutthroat Trout O. clarkii utah (hereafter, Cutthroat Trout) as potential biological control agents. We measured a combination of diet, growth, temperature, and abundance and used bioenergetic simulations to quantify predator demand versus prey supply. Utah Chub were the predominant prey type for tiger trout, contributing up to 80% of the diet depending on the season. Utah Chub represented up to 70% of the total diet consumed by Cutthroat Trout. Although Utah Chub dominated the fish biomass in the reservoir, we still estimated abundances of 238,000 tiger trout, 214,000 Cutthroat Trout, and 55,000 Rainbow Trout. Consequently, when expanded to the population level of each predator, tiger trout and Cutthroat Trout consumed large quantities of Utah Chub on an annual basis: tiger trout consumed 508,000 kg (2,660 g/predator) of the standing prey population, and Cutthroat Trout consumed an estimated 322,000 kg (1,820 g/predator). The estimated combined consumption by Cutthroat Trout and tiger trout exceeded the estimate of Utah Chub annual production. As such, our results suggest that the high rates of piscivory exhibited by Cutthroat Trout and tiger trout in artificial lentic ecosystems are likely sufficient to effectively reduce the overall abundance of forage fishes and to prevent forage fishes from dominating fish assemblages. Collectively, this research provides the first documented findings on tiger trout ecology and performance

  6. Investigating genomic and phenotypic parallelism between piscivorous and planktivorous lake trout (Salvelinus namaycush) ecotypes by means of RADseq and morphometrics analyses.

    Science.gov (United States)

    Bernatchez, S; Laporte, M; Perrier, C; Sirois, P; Bernatchez, L

    2016-10-01

    Repeated adaptive ecological diversification has commonly been reported in fish and has often been associated with trophic niche diversity. The main goal of this study was to investigate the extent of parallelism in the genomic and phenotypic divergence between piscivorous and planktivorous lake trout ecotypes from Laurentian Shield lakes, Canada. This was achieved by documenting the extent of morphological differentiation using geometric morphometrics and linear measurements as well as the pattern of genomic divergence by means of RADseq genotyping (3925 filtered SNPs) in 12 lakes. Our results indicate that the two ecotypes evolved distinct body shape and several linear measurements in parallel. Neutral genetic differentiation was pronounced between all isolated populations (Mean FST  = 0.433), indicating no or very limited migration and pronounced genetic drift. Significant genetic differentiation also suggested partial reproductive isolation between ecotypes in the two lakes where they are found in sympatry. Combining different outlier detection methods, we identified 48 SNPs putatively under divergent selection between ecotypes, among which 10 could be annotated and related to functions such as developmental processes and ionic regulation. Finally, our results indicate that parallel morphological divergence is accompanied by both parallel and nonparallel genomic divergence, which is associated with the use of different trophic niches between ecotypes. The results are also discussed in the context of management and conservation of this highly exploited species throughout northern North America. © 2016 John Wiley & Sons Ltd.

  7. Morphological and molecular confirmation of Myxobolus cerebralis myxospores infecting wild‑caught and cultured trout in North Carolina (SE USA).

    Science.gov (United States)

    Ruiz, Carlos F; Rash, Jacob M; Arias, Cova R; Besler, Doug A; Orélis-Ribeiro, Raphael; Womble, Matthew R; Roberts, Jackson R; Warren, Micah B; Ray, Candis L; Lafrentz, Stacey; Bullard, Stephen A

    2017-11-21

    We used microscopy and molecular biology to provide the first documentation of infections of Myxobolus cerebralis (Myxozoa: Myxobolidae), the etiological agent of whirling disease, in trout (Salmonidae) from North Carolina (USA) river basins. A total of 1085 rainbow trout Oncorhynchus mykiss, 696 brown trout Salmo trutta, and 319 brook trout Salvelinus fontinalis from 43 localities across 9 river basins were screened. Myxospores were observed microscopically in pepsin-trypsin digested heads of rainbow and brown trout from the Watauga River Basin. Those infections were confirmed using the prescribed nested polymerase chain reaction (PCR; 18S rDNA), which also detected infections in rainbow, brown, and brook trout from the French Broad River Basin and the Yadkin Pee-Dee River Basin. Myxospores were 9.0-10.0 µm (mean ± SD = 9.6 ± 0.4; N = 119) long, 8.0-10.0 µm (8.8 ± 0.6; 104) wide, and 6.0-7.5 µm (6.9 ± 0.5; 15) thick and had polar capsules 4.0-6.0 µm (5.0 ± 0.5; 104) long, 2.5-3.5 µm (3.1 ± 0.3; 104) wide, and with 5 or 6 polar filament coils. Myxospores from these hosts and rivers were morphologically indistinguishable and molecularly identical, indicating conspecificity, and the resulting 18S rDNA and ITS-1 sequences derived from these myxospores were 99.5-100% and 99.3-99.8% similar, respectively, to published GenBank sequences ascribed to M. cerebralis. This report comprises the first taxonomic circumscription and molecular confirmation of M. cerebralis in the southeastern USA south of Virginia.

  8. Bull trout distributions related to temperature regimes in four central Idaho streams

    Science.gov (United States)

    Susan B. Adams; Theodore C. Bjornn

    1997-01-01

    bull trout Salvelinus confluentus distributions and water temperature regimes were studied in four streams in the Weiser River basin, Idaho, in 1992 and 1993. bull trout occurred at elevations ranging from 1,472 m to 2,182 m and at densities up to 9.5 fish per 100 m2. Bull trout were sympatric with rainbow trout

  9. Bull trout recovery: Monitoring and evaluation guidance

    Science.gov (United States)

    U.S. Fish and Wildlife Service (USFWS)

    2008-01-01

    Bull trout (Salvelinus confluentus) is an imperiled species of char native to the Pacific Northwest. Combinations of habitat degradation (e.g., Fraley and Shepard 1989), barriers to migration (e.g., Rieman and McIntyre 1995), and the introduction of non-natives (e.g., Leary et al. 1993) have led to the decline of bull trout populations across their...

  10. Diet overlap of top-level predators in recent sympatry: bull trout and nonnative lake trout

    Science.gov (United States)

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

    2011-01-01

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

  11. Results of a nine year study (1972-80) of the sport fishing exploitation of lake trout (Salvelinus namaycush) on Great Slave and Great Bear lakes, NWT: the nature of the resource and management options

    National Research Council Canada - National Science Library

    Yaremchuk, G.C

    1986-01-01

    Data from creel census, tagging and experimental gillnetting at sport fishing lodges on Great Slave and Great Bear lakes are examined in order to ascertain the status of lake trout stocks in the lakes...

  12. Bull Trout Life History, Genetics, Habitat Needs, and Limiting Factors in Central and Northeast Oregon. Annual Report 1996.

    Energy Technology Data Exchange (ETDEWEB)

    Bellerud, Blane L.; Gunckel, Stephanie; Hemmingsen, Alan R.; Buchanan, David V.; Howell, Philip J.

    1997-10-01

    This study is part of a multi-year research project studying aspects of bull trout life history, ecology and genetics. This report covers the activities of the project in 1996. Results and analysis are presented in the following five areas: (1) analysis of the genetic structure of Oregon bull trout populations; (2) distribution and habitat use of bull trout and brook trout in streams containing both species; (3) bull trout spawning surveys; (4) summary and analysis of historical juvenile bull trout downstream migrant trap catches in the Grande Ronde basin; and (5) food habits and feeding behavior of bull trout alone and in sympatry with brook trout.

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

    National Research Council Canada - National Science Library

    Bertolo, Andrea; Pépino, Marc; Adams, Julie; Magnan, Pierre

    2011-01-01

    .... 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...

  14. Southwestern Alaska rainbow trout investigations, Gertrude Creek, Becharof National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Rainbow trout (Oncorhvnchus mvkiss), char (Salvelinus sp.), and Arctic grayling (Thvmallus arcticus) were investigated during June and September, 1988 at Gertrude...

  15. Development of bull trout sampling protocols

    Science.gov (United States)

    R. F. Thurow; J. T. Peterson; J. W. Guzevich

    2001-01-01

    This report describes results of research conducted in Washington in 2000 through Interagency Agreement #134100H002 between the U.S. Fish and Wildlife Service (USFWS) and the U.S. Forest Service Rocky Mountain Research Station (RMRS). The purpose of this agreement is to develop a bull trout (Salvelinus confluentus) sampling protocol by integrating...

  16. Genetic Inventory of Bull Trout and Westslope Cutthroat Trout in Pend Oreille Subbasin, 2003-2004 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Olson, Jason; Maroney, Joseph R.; Andersen, Todd (Kalispel Department of Natural Resources, Usk, WA)

    2004-11-01

    In 2003, the Kalispel Natural Resource Department (KNRD) collected tissue samples for genetic analysis from 209 bull trout and 1,276 westslope cutthroat. The Washington Department of Fish and Wildlife developed and applied microsatellite DNA screening protocols for the analysis of bull trout at 13 loci and 24 loci for cutthroat trout. This project will continue collection and analysis of additional samples next year. At that time, a final annual report will be compiled for the three-year study that will describe the genetic characteristics for bull trout and westslope cutthroat trout. The extent of hybridization of bull trout (with brook trout) and westslope cutthroat trout (with Yellowstone cutthroat trout and rainbow trout) in the Priest Lake and Lower Pend Oreille subbasins will also be examined.

  17. Genetic Inventory of Bull Trout and Westslope Cutthroat Trout in the Pend Oreille Subbasin, 2002-2003 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Maroney, Joseph R. (Kalispel Tribe of Indians, Usk, WA); Shaklee, James B.; Young, Sewall F. (Washington Department of Fish and Wildlife, Olympia, WA)

    2003-10-01

    In 2002, the Kalispel Natural Resource Department (KNRD) collected tissue samples for genetic analysis from 280 bull trout and 940 westslope cutthroat. The Washington Department of Fish and Wildlife developed and applied microsatellite DNA screening protocols for the analysis of bull trout at 13 loci and 24 loci for cutthroat trout. This project will continue collection and analysis of additional samples for the next 2 years. At that time, a final annual report will be compiled for the three-year study that will describe the genetic characteristics for bull trout and westslope cutthroat trout. The extent of hybridization of bull trout (with brook trout) and westslope cutthroat trout (with Yellowstone cutthroat trout and rainbow trout) in the Priest Lake and Lower Pend Oreille subbasins will also be examined.

  18. Physical, biotic, and sampling influences on diel habitat use by stream-dwelling bull trout

    Science.gov (United States)

    Nolan P. Banish; James T. Peterson; Russell F. Thurow

    2008-01-01

    We used daytime and nighttime underwater observation to assess microhabitat use by bull trout Salvelinus confluentus (N = 213) in streams of the intermountain western USA during the summers of 2001 and 2002. We recorded fish focal points and measured a set of habitat characteristics as well as habitat availability via line transects. Bull trout were...

  19. 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.

  20. Suppression of invasive lake trout in an isolated backcountry lake in Glacier National Park

    Science.gov (United States)

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

    2017-01-01

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

  1. Effective population size and genetic conservation criteria for bull trout

    Science.gov (United States)

    Bruce E. Rieman; F. W. Allendorf

    2001-01-01

    Effective population size (Ne) is an important concept in the management of threatened species like bull trout Salvelinus confluentus. General guidelines suggest that effective population sizes of 50 or 500 are essential to minimize inbreeding effects or maintain adaptive genetic variation, respectively....

  2. 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...

  3. 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.

  4. Spawning and rearing behavior of bull trout in a headwaterlake ecosystem

    Science.gov (United States)

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

    2015-01-01

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

  5. Anticipated climate warming effects on bull trout habitats and populations across the interior Columbia River basin

    Science.gov (United States)

    Bruce E. Rieman; Daniel Isaak; Susan Adams; Dona Horan; David Nagel; Charles Luce; Deborah Myers

    2007-01-01

    A warming climate could profoundly affect the distribution and abundance of many fishes. Bull trout Salvelinus confluentus may be especially vulnerable to climate change given that spawning and early rearing are constrained by cold water temperatures creating a patchwork of natal headwater habitats across river networks. Because the size and...

  6. Conservation genetics of bull trout: Geographic distribution of variation at microsatellite loci.

    Science.gov (United States)

    P. Spruell; A.R. Hemmingsen; P.J. Howell; N. Kanda; F.W. Allendorf

    2003-01-01

    We describe the genetic population structure of 65 bull trout (Salvelinus confluentus) populations from the northwestern United States using four microsatellite loci. The distribution of genetic variation as measured by microsatellites is consistent with previous allozyme and mitochondrial DNA analysis. There is relatively little genetic variation...

  7. Sources and magnitude of sampling error in redd counts for bull trout

    Science.gov (United States)

    Jason B. Dunham; Bruce Rieman

    2001-01-01

    Monitoring of salmonid populations often involves annual redd counts, but the validity of this method has seldom been evaluated. We conducted redd counts of bull trout Salvelinus confluentus in two streams in northern Idaho to address four issues: (1) relationships between adult escapements and redd counts; (2) interobserver variability in redd...

  8. Demographic characteristics of an adfluvial bull trout population in Lake Pend Oreille, Idaho

    Science.gov (United States)

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

    2016-01-01

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

  9. Use of electricity to sedate Lake Trout for intracoelomic implantation of electronic transmitters

    Science.gov (United States)

    Faust, Matthew D.; Vandergoot, Christopher; Hostnik, Eric T.; Binder, Thomas R.; Mida Hinderer, Julia L.; Ives, Jessica T.; Krueger, Charles C.

    2017-01-01

    Use of telemetry data to inform fisheries conservation and management is becoming increasingly common; as such, fish typically must be sedated before surgical implantation of transmitters into the coelom. Given that no widely available, immediate-release chemical sedative currently exists in North America, we investigated the feasibility of using electricity to sedate Lake Trout Salvelinus namaycush long enough for an experienced surgeon to implant an electronic transmitter (i.e., 180 s). Specifically, our study objectives were to determine (1) whether some combination of electrical waveform characteristics (i.e., duty cycle, frequency, voltage, and pulse type) could sedate Lake Trout for at least 180 s; and (2) whether Lake Trout that were sequentially exposed to continuous DC and pulsed DC had greater rates of spinal injury and short-term mortality than control fish. A Portable Electrosedation System unit was used to sedate hatchery and wild Lake Trout. Dual-frequency pulsed-DC and two-stage approaches successfully sedated Lake Trout and had similar induction and recovery times. Lake Trout sedated using the two-stage approach did not have survival rates or spinal abnormalities that were significantly different from those of control fish. We concluded that electricity was a viable alternative to chemical sedatives for sedating Lake Trout before surgical implantation of an electronic transmitter, but we suggest that Lake Trout and other closely related species (e.g., Arctic Char Salvelinus alpinus) may require morphotype-specific electrical waveforms due to their morphological diversity.

  10. Maturity schedules of lake trout in Lake Michigan

    Science.gov (United States)

    Madenjian, Charles P.; DeSorcie, Timothy J.; Stedman, Ralph M.

    1998-01-01

    We determined maturity schedules of male and female lake trout (Salvelinus namaycush) in Lake Michigan from nearshore populations and from an offshore population on Sheboygan Reef, which is located in midlake. Gill nets and bottom trawls were used to catch lake trout in fall 1994 and 1995 from two nearshore sites and Sheboygan Reef. Each lake trout was judged immature or mature, based on visual examination of gonads. Probit analysis, coupled with relative potency testing, revealed that age-at-maturity and length-at-maturity were similar at the two nearshore sites, but that lake trout from the nearshore sites matured at a significantly earlier age than lake trout from Sheboygan Reef. However, length at maturity for the nearshore populations was nearly identical to that for the offshore population, suggesting that rate of lake trout maturation in Lake Michigan was governed by growth rather than age. Half of the lake trout males reached maturity at a total length of 580 mm, whereas half of the females were mature at a length of 640 mm. Over half of nearshore males were mature by age 5, and over half the nearshore females matured by age 6. Due to a slower growth rate, maturity was delayed by 2 years on Sheboygan Reef compared with the nearshore populations. Documentation of this delay in maturation may be useful in deciding stocking allocations for lake trout rehabilitation in Lake Michigan.

  11. Evidence of Lake Trout reproduction at Lake Michigan's mid-lake reef complex

    Science.gov (United States)

    Janssen, J.; Jude, D.J.; Edsall, T.A.; Paddock, R.W.; Wattrus, N.; Toneys, M.; McKee, P.

    2006-01-01

    The Mid-Lake Reef Complex (MLRC), a large area of deep (> 40 m) reefs, was a major site where indigenous lake trout (Salvelinus namaycush) in Lake Michigan aggregated during spawning. As part of an effort to restore Lake Michigan's lake trout, which were extirpated in the 1950s, yearling lake trout have been released over the MLRC since the mid-1980s and fall gill net censuses began to show large numbers of lake trout in spawning condition beginning about 1999. We report the first evidence of viable egg deposition and successful lake trout fry production at these deep reefs. Because the area's existing bathymetry and habitat were too poorly known for a priori selection of sampling sites, we used hydroacoustics to locate concentrations of large fish in the fall; fish were congregating around slopes and ridges. Subsequent observations via unmanned submersible confirmed the large fish to be lake trout. Our technological objectives were driven by biological objectives of locating where lake trout spawn, where lake trout fry were produced, and what fishes ate lake trout eggs and fry. The unmanned submersibles were equipped with a suction sampler and electroshocker to sample eggs deposited on the reef, draw out and occasionally catch emergent fry, and collect egg predators (slimy sculpin Cottus cognatus). We observed slimy sculpin to eat unusually high numbers of lake trout eggs. Our qualitative approaches are a first step toward quantitative assessments of the importance of lake trout spawning on the MLRC.

  12. Diel resource partitioning among juvenile Atlantic Salmon, Brown Trout, and Rainbow Trout during summer

    Science.gov (United States)

    Johnson, James H.; McKenna, James E.

    2015-01-01

    Interspecific partitioning of food and habitat resources has been widely studied in stream salmonids. Most studies have examined resource partitioning between two native species or between a native species and one that has been introduced. In this study we examine the diel feeding ecology and habitat use of three species of juvenile salmonids (i.e., Atlantic Salmon Salmo salar, Brown Trout Salmo trutta, and Rainbow Trout Oncorhynchus mykiss) in a tributary of Skaneateles Lake, New York. Subyearling Brown Trout and Rainbow Trout fed more heavily from the drift than the benthos, whereas subyearling Atlantic Salmon fed more from the benthos than either species of trout. Feeding activity of Atlantic Salmon and Rainbow Trout was similar, with both species increasing feeding at dusk, whereas Brown Trout had no discernable feeding peak or trough. Habitat availability was important in determining site-specific habitat use by juvenile salmonids. Habitat selection was greater during the day than at night. The intrastream, diel, intraspecific, and interspecific variation we observed in salmonid habitat use in Grout Brook illustrates the difficulty of acquiring habitat use information for widespread management applications.

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

    Science.gov (United States)

    Lauri Monnot; Jason B. Dunham; Tammy Hoem; Peter Koetsier

    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...

  14. Diel habitat partitioning by bull charr and cutthroat trout during fall and winter in Rocky Mountain streams

    Science.gov (United States)

    Michael J. Jakober; Thomas E. McMahon; Russell F. Thurow

    2000-01-01

    We used underwater observation to determine diel habitat partitioning between bull charr, Salvelinus confluentus, and cutthroat trout, Oncorhynchus clarki, during fall and winter (0.1-8.3°C) in two Rocky Mountain streams that differed in habitat availability. The majority (>70%) of both species emerged from concealment cover at night, though bull charr exhibited a...

  15. Fine-scale characteristics of fluvial bull trout redds and adjacent sites in Rapid River, Idaho, 1993-2007

    Science.gov (United States)

    John W. Guzevich; Russell F. Thurow

    2017-01-01

    From 1993 to 2007, we used single pass, September surveys to locate and measure fluvial bull trout (Salvelinus confluentus) redds in Rapid River, Idaho. Here we describe substrate sizes, redd dimensions, and water depths, velocities, and temperatures within and adjacent to 337 redds. Most (79%) spawning sites had fewer than 20% surface fines (< 2 mm) and mean,...

  16. Effects of fine sediment, hyporheic flow, and spawning site characteristics on survival and development of bull trout embryos

    Science.gov (United States)

    Bowerman, Tracy; Neilson, Bethany; Budy, Phaedra

    2014-01-01

    Successful spawning is imperative for the persistence of salmonid populations, but relatively little research has been conducted to evaluate factors affecting early life-stage survival for bull trout (Salvelinus confluentus), a threatened char. We conducted a field experiment to assess the relationship between site-specific environmental factors and bull trout embryo survival and fry emergence timing. Survival from egg to hatch was negatively related to percent fine sediment (hydraulic conductivity via redd construction and selection of spawning sites with strong downwelling appear to enhance hyporheic flow rates and bull trout egg survival, but early life-stage success may ultimately be limited by intrusion of fine sediment into the incubation environment.

  17. 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.

  18. Factors influencing the distribution of native bull trout and westslope cutthroat trout in western Glacier National Park, Montana

    Science.gov (United States)

    D'Angelo, Vincent S.; Muhlfeld, Clint C.

    2013-01-01

    The widespread declines of native bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarkii lewisi) populations prompted researchers to investigate factors influencing their distribution and status in western Glacier National Park, Montana. We evaluated the association of a suite of abiotic factors (stream width, elevation, gradient, large woody debris density, pool density, August mean stream temperature, reach surface area) with the occurrence (presence or absence) of bull trout and westslope cutthroat trout in 79 stream reaches in five sub-drainages containing glacial lakes. We modeled the occurrence of each species using logistic regression and evaluated competing models using an information theoretic approach. Westslope cutthroat trout were widely distributed (47 of 79 reaches), and there appeared to be no restrictions on their distribution other than physical barriers. Westslope cutthroat trout were most commonly found in relatively warm reaches downstream of lakes and in headwater reaches with large amounts of large woody debris and abundant pools. By contrast, bull trout were infrequently detected (10 of 79 reaches), with 7 of the 10 (70%) detections in sub-drainages that have not been compromised by non-native lake trout (S. namaycush). Bull trout were most often found in cold, low-gradient reaches upstream of glacial lakes. Our results indicate that complex stream habitats in sub-drainages free of non-native species are important to the persistence of native salmonids in western Glacier National Park. Results from this study may help managers monitor and protect important habitats and populations, inform conservation and recovery programs, and guide non-native species suppression efforts in Glacier National Park and elsewhere.

  19. Sampling strategies for estimating brook trout effective population size

    Science.gov (United States)

    Andrew R. Whiteley; Jason A. Coombs; Mark Hudy; Zachary Robinson; Keith H. Nislow; Benjamin H. Letcher

    2012-01-01

    The influence of sampling strategy on estimates of effective population size (Ne) from single-sample genetic methods has not been rigorously examined, though these methods are increasingly used. For headwater salmonids, spatially close kin association among age-0 individuals suggests that sampling strategy (number of individuals and location from...

  20. Influences of temperature and environmental variables on the distribution of bull trout within streams at the southern margin of its range

    Science.gov (United States)

    J. Dunham; B. Rieman; G. Chandler

    2003-01-01

    The bull trout Salvelinus confluentus is believed to be among the most thermally sensitive species in coldwater habitats in western North America. We conducted a comprehensive field assessment of thermal habitat associations throughout the southern margin of the species' range. We developed models of thermal habitat associations using two data sets representing a...

  1. An expert panel approach to assessing potential effects of bull trout reintroduction on federally listed salmonids in the Clackamas River, Oregon

    Science.gov (United States)

    Bruce G. Marcot; Chris S. Allen; Steve Morey; Dan Shively; Rollie. White

    2012-01-01

    The bull trout Salvelinus confluentus is an apex predator in native fish communities in the western USA and is listed as threatened under the U.S. Endangered Species Act (ESA). Restoration of this species has raised concerns over its potential predatory impacts on native fish fauna. We held a five-person expert panel to help determine potential...

  2. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  4. A Regional View of the Margin: Salmonid Abundance and Distribution in the Southern Appalachian Mountains of North Carolina and Virginia

    Science.gov (United States)

    Patricia A. Flebbe

    1994-01-01

    In the southern Appalachian Mountains, native brook trout Salvelinus fontinalis and introduced rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta are at the southern extremes of their distributions, an often overlooked kind of marginal habitat. At a regional scale composed of the states of Virginia...

  5. 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).

  6. Wigwam River Juvenile Bull Trout and Fish Habitat Monitoring Program : 2000 Data Report.

    Energy Technology Data Exchange (ETDEWEB)

    Cope, R.S.; Morris, K.J.

    2001-03-01

    The Wigwam River bull trout (Salvelinus confluentus) and fish habitat monitoring program is a trans-boundary initiative implemented by the British Columbia Ministry of 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).

  7. Life history migrations of adult Yellowstone Cutthroat Trout in the upper Yellowstone River

    Science.gov (United States)

    Ertel, Brian D.; McMahon, Thomas E.; Koel, Todd M.; Gresswell, Robert E.; Burckhardt, Jason

    2017-01-01

    Knowledge of salmonid life history types at the watershed scale is increasingly recognized as a cornerstone for effective management. In this study, we used radiotelemetry to characterize the life history movements of Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri in the upper Yellowstone River, an extensive tributary that composes nearly half of the drainage area of Yellowstone Lake. In Yellowstone Lake, Yellowstone Cutthroat Trout have precipitously declined over the past 2 decades primarily due to predation from introduced Lake Trout Salvelinus namaycush. Radio tags were implanted in 152 Yellowstone Cutthroat Trout, and their movements monitored over 3 years. Ninety-six percent of tagged trout exhibited a lacustrine–adfluvial life history, migrating upstream a mean distance of 42.6 km to spawn, spending an average of 24 d in the Yellowstone River before returning to Yellowstone Lake. Once in the lake, complex postspawning movements were observed. Only 4% of radio-tagged trout exhibited a fluvial or fluvial–adfluvial life history. Low prevalence of fluvial and fluvial–adfluvial life histories was unexpected given the large size of the upper river drainage. Study results improve understanding of life history diversity in potamodromous salmonids inhabiting relatively undisturbed watersheds and provide a baseline for monitoring Yellowstone Cutthroat Trout response to management actions in Yellowstone Lake.

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

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Jeremy; Baxter, James S.

    2002-12-01

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

  9. Monitor and Protect Wigwam River Bull Trout for Koocanusa Reservoir : Summary of the Skookumchuck Creek Bull Trout Enumeration Project, Annual Report 2001.

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, James S.; Baxter, Jeremy

    2002-03-01

    This report summarizes the second year of a bull trout (Salvelinus confluentus) enumeration project on Skookumchuck Creek in southeastern British Columbia. An enumeration fence and traps were installed on the creek from September 6th to October 12th 2001 to enable the capture of post-spawning bull trout emigrating out of the watershed. During the study period, a total of 273 bull trout were sampled through the enumeration fence. Length and weight were determined for all bull trout captured. In total, 39 fish of undetermined sex, 61 males and 173 females were processed through the fence. An additional 19 bull trout were observed on a snorkel survey prior to the fence being removed on October 12th. Coupled with the fence count, the total bull trout enumerated during this project was 292 fish. Several other species of fish were captured at the enumeration fence including westslope cutthroat trout (Oncorhynchus clarki lewisi), Rocky Mountain whitefish (Prosopium williamsoni), and kokanee (O. nerka). A total of 143 bull trout redds were enumerated on the ground in two different locations (river km 27.5-30.5, and km 24.0-25.5) on October 3rd. The majority of redds (n=132) were observed in the 3.0 km index section (river km 27.5-30.5) that has been surveyed over the past five years. The additional 11 redds were observed in a 1.5 km section (river km 24.0-25.5). Summary plots of water temperature for Bradford Creek, Sandown Creek, Buhl Creek, and Skookumchuck Creek at three locations suggested that water temperatures were within the temperature range preferred by bull trout for spawning, egg incubation, and rearing.

  10. Trophic ontogeny of fluvial Bull Trout and seasonal predation on Pacific Salmon in a riverine food web

    Science.gov (United States)

    Lowery, Erin D.; Beauchamp, David A.

    2015-01-01

    Bull Trout Salvelinus confluentus are typically top predators in their host ecosystems. The Skagit River in northwestern Washington State contains Bull Trout and Chinook Salmon Oncorhynchus tshawytschapopulations that are among the largest in the Puget Sound region and also contains a regionally large population of steelhead O. mykiss (anadromous Rainbow Trout). All three species are listed as threatened under the Endangered Species Act (ESA). Our objective was to determine the trophic ecology of Bull Trout, especially their role as predators and consumers in the riverine food web. We seasonally sampled distribution, diets, and growth of Bull Trout in main-stem and tributary habitats during 2007 and winter–spring 2008. Consumption rates were estimated with a bioenergetics model to (1) determine the annual and seasonal contributions of different prey types to Bull Trout energy budgets and (2) estimate the potential impacts of Bull Trout predation on juvenile Pacific salmon populations. Salmon carcasses and eggs contributed approximately 50% of the annual energy budget for large Bull Trout in main-stem habitats, whereas those prey types were largely inaccessible to smaller Bull Trout in tributary habitats. The remaining 50% of the energy budget was acquired by eating juvenile salmon, resident fishes, and immature aquatic insects. Predation on listed Chinook Salmon and steelhead/Rainbow Trout was highest during winter and spring (January–June). Predation on juvenile salmon differed between the two study years, likely due to the dominant odd-year spawning cycle for Pink Salmon O. gorbuscha. The population impact on ocean- and stream-type Chinook Salmon was negligible, whereas the impact on steelhead/Rainbow Trout was potentially very high. Due to the ESA-listed status of Bull Trout, steelhead, and Chinook Salmon, the complex trophic interactions in this drainage provide both challenges and opportunities for creative adaptive management strategies.

  11. Effects of lake trout refuges on lake whitefish and cisco in the Apostle Islands Region of Lake Superior

    Science.gov (United States)

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

    2016-01-01

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

  12. 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.

  13. 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

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

    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.

  15. 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

  16. Effect of stocking sub-yearling Atlantic salmon on the habitat use of sub-yearling rainbow trout

    Science.gov (United States)

    Johnson, James H.

    2016-01-01

    Atlantic salmon (Salmo salar) restoration in the Lake Ontario watershed may depend on the species' ability to compete with naturalized non-native salmonids, including rainbow trout (Oncorhynchus mykiss) in Lake Ontario tributaries. This study examined interspecific habitat associations between sub-yearling Atlantic salmon and rainbow trout as well as the effect of salmon stocking on trout habitat in two streams in the Lake Ontario watershed. In sympatry, Atlantic salmon occupied significantly faster velocities and deeper areas than rainbow trout. However, when examining the habitat use of rainbow trout at all allopatric and sympatric sites in both streams, trout habitat use was more diverse at the sympatric sites with an orientation for increased cover and larger substrate. In Grout Brook, where available habitat remained constant, there was evidence suggesting that trout may have shifted to slower and shallower water in the presence of salmon. The ability of sub-yearling Atlantic salmon to affect a habitat shift in rainbow trout may be due to their larger body size and/or larger pectoral fin size. Future studies examining competitive interactions between these species during their first year of stream residence should consider the size advantage that earlier emerging Atlantic salmon will have over rainbow trout.

  17. A blocking primer increases specificity in environmental DNA detection of bull trout (Salvelinus confluentus)

    Science.gov (United States)

    Taylor M. Wilcox; Michael K. Schwartz; Kevin S. McKelvey; Michael K. Young; Winsor H. Lowe

    2014-01-01

    Environmental DNA (eDNA) is increasingly applied as a highly sensitive way to detect aquatic animals non-invasively. However, distinguishing closely related taxa can be particularly challenging. Previous studies of ancient DNA and genetic diet analysis have used blocking primers to enrich target template in the presence of abundant, non-target DNA. Here we apply a...

  18. Thiamine deficiency effects on the vision and foraging ability of lake trout fry

    Science.gov (United States)

    Tillitt, Donald E.; Zajicek, James L.; Claunch, Rachel; Honeyfield, Dale C.; Fitzsimons, John D.; Brown, Scott B.

    2008-01-01

    The exact causes of the historical recruitment failures of Great Lakes lake trout Salvelinus namaycush are unknown. Thiamine deficiency has been associated with neurological abnormalities in lake trout that lead to early mortality syndrome (EMS) in salmonine swim-up fry, and EMS-related mortality at the swim-up stage is a factor that contributes to the reproductive failure of lake trout populations in the Great Lakes. The potential for adverse effects of thiamine deficiency beyond the swim-up stage is unknown. We investigated the effects of low egg thiamine on behavioral functions in young, post-swim-up lake trout fry. The behavioral endpoints included visual acuity and prey capture rates in the same groups of lake trout fry from each family. Low-thiamine eggs were produced by feeding lake trout broodstock diets entailing thiaminase activity. The thiamine content of the spawned eggs ranged from 0.3 to 26.1 nmol/g. Both visual acuity and prey capture rates were affected by the thiamine content of the eggs. The visual acuity of lake trout was severely affected by low egg thiamine, mainly at thiamine concentrations below the threshold of 0.8 nmol/g but also at higher concentrations in field-collected eggs. Feeding was also reduced with low egg thiamine content. The reduction of prey capture rates was dramatic below 0.8 nmol/g and less dramatic, but still significant, in a portion of the families with egg thiamine concentrations of less than 5.0 nmol/g from both laboratory and field samples. Approximately one-third of the latter families had reduced feeding rates. Deficits in visual acuity may be part of the mechanism leading to decreased feeding rates in these fry. The effects of low egg thiamine on both of the behavioral endpoints studied increase the risk of low recruitment rates in Great Lakes lake trout populations.

  19. Monitor and Protect Wigwam River Bull Trout for Koocanusa Reservoir : Summary of the Skookumchuck Creek Bull Trout Enumeration Project, Annual Report 2000.

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, James S.; Baxter, Jeremy

    2001-02-01

    An enumeration fence and traps were installed on Skookumchuck Creek from September 7 th to October 16 th to enable the capture of post-spawning bull trout emigrating out of the watershed. During the study period, a total of 252 bull trout were sampled through the enumeration fence. Length, weight, and sex were determined for all but one of the 252 bull trout captured. In total, one fish of undetermined sex, 63 males and 188 females were processed through the fence. A total of 67 bull trout were observed on a snorkel survey prior to the fence being removed on October 16 th . Coupled with the fence count, the total bull trout count during this project was 319 fish. Several other species of fish were captured at the enumeration fence including westslope cutthroat trout, Rocky Mountain whitefish, kokanee, sucker, and Eastern brook trout. Redds were observed during ground surveys in three different locations (river km 27.5- 28.5, km 29-30, and km 24-25). The largest concentration of redds were noted in the upper two sections which have served as the index sections over the past four years. A total of 197 bull trout redds were enumerated on the ground on October 4 th . The majority of redds (n=189) were observed in the 3.0 km index section (river km 27.5-30.5) that has been surveyed over the past four years. The additional 8 redds were observed in a 1.5 km section (river km 24.0-25.5). Summary plots of water temperature for Bradford Creek, Sandown Creek, Skookumchuck Creek at km 39.5, and Skookumchuck Creek at the fence site suggested that water temperatures were within the range preferred by bull trout for spawning, egg incubation, and rearing.

  20. Marine Habitat Use by Anadromous Bull Trout from the Skagit River, Washington

    Science.gov (United States)

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

    2011-01-01

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

  1. 2012 USGS Lidar: Brooks Camp (AK)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Geological Survey (USGS) had a requirement for high resolution Lidar needed for mapping the Brooks Camp region of Katmai National Park in Alaska....

  2. Katherine Brooke'ist / Tiina Lepiste

    Index Scriptorium Estoniae

    Lepiste, Tiina

    2007-01-01

    Ameerika teleseriaali "Vaprad ja ilusad" ("The Bold and the Beautiful") osatäitja Katherine Kelly Lang (Brooke). Artikli aluseks on Soap Opera Weekly ajakirjaniku Linda Susmani vestlus näitlejannaga

  3. Reestablishing a spawning population of lake trout in Lake Superior with fertilized eggs in artificial turf incubators

    Science.gov (United States)

    Bronte, Charles R.; Schram, Stephen T.; Selgeby, James H.; Swanson, Bruce L.

    2002-01-01

    Fertilized eggs from lake trout Salvelinus namaycush were placed in artificial turf incubators and deployed on Devils Island Shoal, Lake Superior, in an attempt to reestablish a spawning population on this once important spawning area. Efficacy was measured by the changes in catch rates, age composition, and origin of adult lake trout returning to the shoal in the fall in subsequent years. The abundance of lake trout spawners without fin clips, which implies that these fish hatched in the lake, increased throughout the sampling period, whereas the abundance of hatchery-reared fish (indicated by one or more fin clips) stocked for restoration purposes remained low. Year-class-specific stock-recruitment analysis suggested that the recruitment of unclipped spawners was related to the number of eggs planted in previous years rather than to spawning by the few adult lake trout visiting the reef. Increases in adult fish at Devils Island Shoal were independent of trends at adjacent sites, where unclipped spawner abundances remained low. Enhanced survival to hatch and apparent site imprinting of young lake trout make this technique a viable alternative to stocking fingerling and yearling lake trout to reestablish spawning populations on specific sites in the Great Lakes.

  4. 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.

  5. 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

  6. Evaluating trade-offs in bull trout reintroduction strategies using structured decision making

    Science.gov (United States)

    Brignon, William R.; Peterson, James T.; Dunham, Jason; Schaller, Howard A.; Schreck, Carl B.

    2018-01-01

    Structured decision making allows reintroduction decisions to be made despite uncertainty by linking reintroduction goals with alternative management actions through predictive models of ecological processes. We developed a decision model to evaluate the trade-offs between six bull trout (Salvelinus confluentus) reintroduction decisions with the goal of maximizing the number of adults in the recipient population without reducing the donor population to an unacceptable level. Sensitivity analyses suggested that the decision identity and outcome were most influenced by survival parameters that result in increased adult abundance in the recipient population, increased juvenile survival in the donor and recipient populations, adult fecundity rates, and sex ratio. The decision was least sensitive to survival parameters associated with the captive-reared population, the effect of naivety on released individuals, and juvenile carrying capacity of the reintroduced population. The model and sensitivity analyses can serve as the foundation for formal adaptive management and improved effectiveness, efficiency, and transparency of bull trout reintroduction decisions.

  7. 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

  8. A comparison of two mobile electrode arrays for increasing mortality of Lake Trout embryos

    Science.gov (United States)

    Brown, Peter J.; Guy, Christopher S.; Meeuwig, Michael H.

    2017-01-01

    Conservation of sport fisheries and populations of several native fishes in the western United States is dependent on sustained success of removal programs targeting invasive Lake Trout Salvelinus namaycush. Gill-netting of spawning adults is one strategy used to decrease spawning success; however, additional complementary methods are needed to disrupt Lake Trout reproduction where bycatch in gill nets is unacceptable. We developed and tested two portable electrode arrays designed to increase Lake Trout embryo mortality in known spawning areas. Both arrays were powered by existing commercial electrofishing equipment. However, one array was moved across the substrate to simulate being towed behind a boat (i.e., towed array), while the other array was lowered from a boat and energized when sedentary (i.e., sedentary array). The arrays were tested on embryos placed within substrates of known spawning areas. Both arrays increased mortality of embryos (>90%) at the surface of substrates, but only the sedentary array was able to increase mortality to >90% at deeper burial depths. In contrast, embryos at increasingly deeper depths exhibited progressively lower mortality when exposed to the towed array. Mortality of embryos placed under 20 cm of substrate and exposed to the towed array was not significantly different from that of unexposed embryos in a control group. We suggest that the sedentary array could be used as a viable approach for increasing mortality of Lake Trout embryos buried to 20 cm and that it could be modified to be effective at deeper depths.

  9. Effects of gill-net trauma, barotrauma, and deep release on postrelease mortality of Lake Trout

    Science.gov (United States)

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

    2015-01-01

    Unaccounted postrelease mortality violates assumptions of many fisheries studies, thereby biasing parameter estimates and reducing efficiency. We evaluated effects of gill-net trauma, barotrauma, and deep-release treatment on postrelease mortality of lake trout Salvelinus namaycush. Lake trout were captured at depths up to 65 m with gill nets in Priest Lake, Idaho, and held in a large enclosure for 10–12 d. Postrelease mortality was the same for surface-release–and deep-release–treated fish (41%). Mixed-effects logistic regression models were used to evaluate effects of intrinsic and environmental factors on the probability of mortality. Presence of gill-net trauma and degree of barotrauma were associated with increased probability of postrelease mortality. Smaller fish were also more likely to suffer postrelease mortality. On average, deep-release treatment did not reduce postrelease mortality, but effectiveness of treatment increased with fish length. Of the environmental factors evaluated, only elapsed time between lifting the first and last anchors of a gill-net gang (i.e., lift time) was significantly related to postrelease mortality. Longer lift times, which may allow ascending lake trout to acclimate to depressurization, were associated with lower postrelease mortality rates. Our study suggests that postrelease mortality may be higher than previously assumed for lake trout because mortality continues after 48 h. In future studies, postrelease mortality could be reduced by increasing gill-net lift times and increasing mesh size used to increase length of fish captured.

  10. Incorporating movement patterns to improve survival estimates for juvenile bull trout

    Science.gov (United States)

    Bowerman, Tracy; Budy, Phaedra

    2012-01-01

    Populations of many fish species are sensitive to changes in vital rates during early life stages, but our understanding of the factors affecting growth, survival, and movement patterns is often extremely limited for juvenile fish. These critical information gaps are particularly evident for bull trout Salvelinus confluentus, a threatened Pacific Northwest char. We combined several active and passive mark–recapture and resight techniques to assess migration rates and estimate survival for juvenile bull trout (70–170 mm total length). We evaluated the relative performance of multiple survival estimation techniques by comparing results from a common Cormack–Jolly–Seber (CJS) model, the less widely used Barker model, and a simple return rate (an index of survival). Juvenile bull trout of all sizes emigrated from their natal habitat throughout the year, and thereafter migrated up to 50 km downstream. With the CJS model, high emigration rates led to an extreme underestimate of apparent survival, a combined estimate of site fidelity and survival. In contrast, the Barker model, which allows survival and emigration to be modeled as separate parameters, produced estimates of survival that were much less biased than the return rate. Estimates of age-class-specific annual survival from the Barker model based on all available data were 0.218±0.028 (estimate±SE) for age-1 bull trout and 0.231±0.065 for age-2 bull trout. This research demonstrates the importance of incorporating movement patterns into survival analyses, and we provide one of the first field-based estimates of juvenile bull trout annual survival in relatively pristine rearing conditions. These estimates can provide a baseline for comparison with future studies in more impacted systems and will help managers develop reliable stage-structured population models to evaluate future recovery strategies.

  11. The Brooks Act, Is it Relevant Today?

    Science.gov (United States)

    1994-06-01

    Publishing Company, 1990. 7. Fla=., Kenneth. Creatina The ComDuter. Washington, D.C.: The Brookings Institution, 1988. 8. Gilchrist, Bruce, & Wessel...Milton R. Reaulation of the Computer Industry. Montvale: AFIPS Press, 1972. 9. Gore, Al. Creatina A Government That Works Better & Cost Less: Renort

  12. Cold Spring Brook Site Investigation Work Plan

    Science.gov (United States)

    1994-11-01

    floodplain is a forested swamp habitat dominated by red maples (Acer rubrum). Various oak species ( Quercus spp.), grey birch (Betula populifolia...Vaccinium corymbosum), and speckled alder (Alnus rugosa ) also occur in the floodplain of Cold Spring Brook. Typical floodplain herbaceous components

  13. 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.

  14. 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.

  15. 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

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

    Directory of Open Access Journals (Sweden)

    Glebe Brian

    2011-09-01

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

  17. Lake trout reproductive behavior: influence of chemosensory cues from young-of-the-year by-products

    Science.gov (United States)

    Foster, Neal R.

    1985-01-01

    Chemosensory cues, particularly those emanating from substrate areas occupied by previously hatched young, may play an important role in the reproductive behavior of lake trout Salvelinus namaycush. Support for this hypothesis was obtained in laboratory experiments. Adults were placed in a large circular pool with four experimental reefs. Egg membranes and feces obtained from young that had hatched earlier were placed in polyester fiber in screen envelopes and positioned on selected reefs. Females approached and males contacted ('cleaned') the treated reefs but not the untreated reefs. Of 6,858 eggs recovered, 92% were from treated reefs. Some of these eggs had been fertilized and provide the first record of volitional spawning by lake trout under artificial conditions. A second experiment was less definitive, because no spawning occurred, but visual observations and analysis of videotaped behavior sequences showed that, again, adults were attracted more to reefs treated with feces of young of the year than to untreated reefs.

  18. Growth of Arctic charr (Salvelinus alpinus L.) in a pilot commercial rearing system

    National Research Council Canada - National Science Library

    Papst, M.H; Hopky, G.E

    1983-01-01

    ... (Salvelinus alpinus L.) are described. After 209 days of growth in a pilot commercial fish production system, at 13 C, the mean weight of individuals in the population increased from 2.2 to 158.1 g...

  19. Nedern Brook Wetland SSSI. Phase 1, hydrological monitoring

    OpenAIRE

    Farr, Gareth

    2016-01-01

    This report provides a description of the first targeted hydrological and hydrogeological investigation at the Nedern Brook Wetland SSSI (described as ‘the wetland’) South Wales. The wetland is designated for its importance for overwintering and wading birds. The Nedern Brook – the water course that flows through the wetland from north to south is classified as a main river, however it has been heavily modified in its lower reaches. Historical alterations to the Nedern Brook, such as straight...

  20. Minimum Pool and Bull Trout Prey Base Investigations at Beulah Reservoir - Final Report for 2008

    Science.gov (United States)

    Rose, Brien P.; Mesa, Matthew G.

    2009-01-01

    Beulah Reservoir in southeastern Oregon provides irrigation water to nearby farms and supports an adfluvial population of threatened bull trout (Salvelinus confluentus). Summer drawdowns in the reservoir could affect forage fish production and overwintering bull trout. To assess the impacts of drawdown, we sampled fish, invertebrates, and water-quality variables seasonally during 2006-08. In 2006, the summer drawdown was about 68 percent of full pool, which was less than a typical drawdown of 85 percent. We detected few changes in pelagic invertebrate densities, and catch rates, abundance, and sizes of fish when comparing values from spring to values from fall. We did note that densities of benthic insects in areas that were dewatered annually were lower than those from areas that were not dewatered annually. In 2007, the drawdown was 100 percent (to run-of-river level) and resulted in decreases in abundance of invertebrates as much as 96 percent, decreases in catch rates of fish as much as 80 percent, decreases in abundance of redside shiners (Richardsonius balteatus) and northern pikeminnow (Ptychocheilus oregonensis) as much as 93 percent, and decreased numbers of small fish in catches. In the fall 2007, we estimated the total biomass of forage fish to be 76 kilograms, or about one-quarter of total biomass of forage fish in 2006. Bioenergetics modeling suggested that ample forage for about 1,000 bull trout would exist after a moderate drawdown, but that forage remaining after a complete dewatering would not be sufficient for a population one-fifth the size. Our results indicate that drawdowns in Beulah Reservoir affect the aquatic community and perhaps the health and well-being of bull trout. The severity of effects depends on the extent of drawdown, population size of bull trout, and perhaps other factors.

  1. Consequences of actively managing a small Bull Trout population in a fragmented landscape

    Science.gov (United States)

    Al-Chokhachy, Robert K.; Moran, Sean; McHugh, Peter; Bernall, Shana; Fredenberg, Wade; DosSantos, Joseph M.

    2015-01-01

    Habitat fragmentation, which affects many native salmonid species, is one of the major factors contributing to the declines in distribution and abundance of Bull Trout Salvelinus confluentus. Increasingly, managers are considering options to maintain and enhance the persistence of isolated local populations through active management strategies. Understanding the ecological consequences of such actions is a necessary step in conservation planning. We used an individual-based model to evaluate the consequences of an ongoing management program aimed at mitigating the anthropogenic fragmentation of the lower Clark Fork River in Montana. Under this program juvenile Bull Trout are trapped and transported from small, headwater source populations to Lake Pend Oreille, Idaho, for rearing, and adults are subsequently recaptured in their upstream migration and returned to the natal population for spawning. We examined one of these populations and integrated empirical estimates of demographic parameters to simulate different management scenarios where moderate (n = 4) and high (n = 8) numbers of age-2, age-3, or age-4 Bull Trout were removed for transport with variable return rates under both demographic stochasticity and environmental perturbations. Our results indicated the risks from removal with no returns increased substantially when removal totals and age of Bull Trout removed from the simulated population increased. Specifically, removing eight age-3 or age-4 individuals resulted in 26% and 62% reductions in average adult population size, respectively, across simulations. We found the risks of transport were not likely alleviated with low (3%) or moderate (6%) return rates, and there were considerable risks of declines for the source population even when return rates were extremely high (>12%). Our simulations indicated little risk of declines for the source population with removals of age-2 Bull Trout, and any risks were alleviated with low return rates. However, we

  2. Genetic diversity is related to climatic variation and vulnerability in threatened bull trout

    Science.gov (United States)

    Kovach, Ryan; Muhlfeld, Clint C.; Wade, Alisa A.; Hand, Brian K.; Whited, Diane C.; DeHaan, Patrick W.; Al-Chokhachy, Robert K.; Luikart, Gordon

    2015-01-01

    Understanding how climatic variation influences ecological and evolutionary processes is crucial for informed conservation decision-making. Nevertheless, few studies have measured how climatic variation influences genetic diversity within populations or how genetic diversity is distributed across space relative to future climatic stress. Here, we tested whether patterns of genetic diversity (allelic richness) were related to climatic variation and habitat features in 130 bull trout (Salvelinus confluentus) populations from 24 watersheds (i.e., ~4–7th order river subbasins) across the Columbia River Basin, USA. We then determined whether bull trout genetic diversity was related to climate vulnerability at the watershed scale, which we quantified on the basis of exposure to future climatic conditions (projected scenarios for the 2040s) and existing habitat complexity. We found a strong gradient in genetic diversity in bull trout populations across the Columbia River Basin, where populations located in the most upstream headwater areas had the greatest genetic diversity. After accounting for spatial patterns with linear mixed models, allelic richness in bull trout populations was positively related to habitat patch size and complexity, and negatively related to maximum summer temperature and the frequency of winter flooding. These relationships strongly suggest that climatic variation influences evolutionary processes in this threatened species and that genetic diversity will likely decrease due to future climate change. Vulnerability at a watershed scale was negatively correlated with average genetic diversity (r = −0.77;P bull trout and other imperiled species. Genetic diversity is already depressed where climatic vulnerability is highest; it will likely erode further in the very places where diversity may be most needed for future persistence.

  3. Landscape influences on genetic differentiation among bull trout populations in a stream-lake network

    Science.gov (United States)

    Meeuwig, M.H.; Guy, C.S.; Kalinowski, S.T.; Fredenberg, W.A.

    2010-01-01

    This study examined the influence of landscape heterogeneity on genetic differentiation between migratory bull trout (Salvelinus confluentus) populations in Glacier National Park, Montana. An information-theoretic approach was used to compare different conceptual models of dispersal associated with barriers, different models of isolation by distance, and the combined effects of barriers, waterway distance, patch size, and intra- and inter-drainage distribution of populations on genetic differentiation between bull trout populations. The effect of distance between populations on genetic differentiation was best explained by partitioning the effects of mainstem and tributary stream sections. Models that categorized barriers as having a one-way effect (i.e. allowed downstream dispersal) or a two-way effect were best supported. Additionally, patch size and the distribution of populations among drainages influenced genetic differentiation. Genetic differentiation between bull trout populations in Glacier National Park is linked to landscape features that restrict dispersal. However, this analysis illustrates that modelling variability within landscape features, such as dispersal corridors, will benefit landscape genetic analyses. Additionally, the framework used for evaluating the effects of barriers must consider not just barrier presence, but also potential asymmetries in barrier effects with respect to the organism under investigation.

  4. Ups and Downs of Burbot and their predator Lake Trout in Lake Superior, 1953-2011

    Science.gov (United States)

    Gorman, Owen T.; Sitar, Shawn P.

    2013-01-01

    The fish community of Lake Superior has undergone a spectacular cycle of decline and recovery over the past 60 years. A combination of Sea Lamprey Petromyzon marinus depredation and commercial overfishing resulted in severe declines in Lake Trout Salvelinus namaycush, which served as the primary top predator of the community. Burbot Lota lota populations also declined as a result of Sea Lamprey depredation, largely owing to the loss of adult fish. After Sea Lamprey control measures were instituted in the early 1960s, Burbot populations rebounded rapidly but Lake Trout populations recovered more slowly and recovery was not fully evident until the mid-1980s. As Lake Trout populations recovered, Burbot populations began to decline, and predation on small Burbot was identified as the most likely cause. By 2000, Burbot densities had dropped below their nadir in the early 1960s and have continued to decline, with the densities of juveniles and small adults falling below that of large adults. Although Burbot populations are at record lows in Lake Superior, the density of large reproductive adults remains stable and a large reserve of adult Burbot is present in deep offshore waters. The combination of the Burbot's early maturation, long life span, and high fecundity provides the species with the resiliency to remain a viable member of the Lake Superior fish community into the foreseeable future.

  5. Successional change in the Lake Superior fish community: population trends in ciscoes, rainbow smelt, and lake trout, 1958-2008

    Science.gov (United States)

    Gorman, Owen T.

    2012-01-01

    The Lake Superior fish community underwent massive changes in the second half of the 20th century. Those changes are largely reflected in changes in abundance of the adults of principal prey species, the ciscoes (Coregonus spp.), the invasive rainbow smelt (Osmerus mordax), and the principal predator, lake trout (Salvelinus namaycush). To better understand changes in species abundances, a comprehensive series of gillnet and bottom trawl data collected from 1958 to 2008 were examined. In the late 1950s/early 1960s, smelt abundance was at its maximum, wild lake trout was at its minimum, and an abundance of hatchery lake trout was increasing rapidly. The bloater (Coregonus hoyi) was the prevalent cisco in the lake; abundance was more than 300% greater than the next most abundant cisco, shortjaw cisco (C. zenithicus), followed by kiyi (C. kiyi) and lake cisco (C. artedi). By the mid-1960s, abundance of hatchery lake trout was nearing maximum, smelt abundance was beginning to decline, and abundances of all ciscoes declined, but especially that of shortjaw cisco and kiyi. By the late 1970s, recovery of wild lake trout stocks was well underway and abundances of hatchery lake trout and smelt were declining and the ciscoes were reaching their nadir. During 1980–1990, the fish community underwent a dramatic shift in organization and structure. The rapid increase in abundance of wild lake trout, concurrent with a rapid decline in hatchery lake trout, signaled the impending recovery. Rainbow smelt abundance dropped precipitously and within four years, lake cisco and bloater populations rebounded on the heels of a series of strong recruitment events. Kiyi populations showed signs of recovery by 1989, and shortjaw by 2000, though well below historic maximum abundances. High abundance of adult smelt prior to 1980 appears to be the only factor linked to recruitment failure in the ciscoes. Life history traits of the cisco species were examined to better understand their different

  6. 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.

  7. Temporal constraints on the potential role of fry odors as cues of past reproductive success for spawning lake trout

    Science.gov (United States)

    Buchinger, Tyler J.; Marsden, J. Ellen; Binder, Thomas R.; Huertas, Mar; Bussy, Ugo; Li, Ke; Hanson, James E.; Krueger, Charles C.; Li, Weiming; Johnson, Nicholas

    2017-01-01

    Deciding where to reproduce is a major challenge for most animals. Many select habitats based upon cues of successful reproduction by conspecifics, such as the presence of offspring from past reproductive events. For example, some fishes select spawning habitat following odors released by juveniles whose rearing habitat overlaps with spawning habitat. However, juveniles may emigrate before adults begin to search for spawning habitat; hence, the efficacy of juvenile cues could be constrained by degradation or dissipation rates. In lake trout (Salvelinus namaycush), odors deposited by the previous year's offspring have been hypothesized to guide adults to spawning reefs. However, in most extant populations, lake trout fry emigrate from spawning reefs during the spring and adults spawn during the fall. Therefore, we postulated that the role of fry odors in guiding habitat selection might be constrained by the time between fry emigration and adult spawning. Time course chemical, physiological, and behavioral assays indicated that the odors deposited by fry likely degrade or dissipate before adults select spawning habitats. Furthermore, fry feces did not attract wild lake trout to constructed spawning reefs in Lake Huron. Taken together, our results indicate fry odors are unlikely to act as cues for lake trout searching for spawning reefs in populations whose juveniles emigrate before the spawning season, and underscore the importance of environmental constraints on social cues.

  8. Effectiveness of a refuge for lake trout in western Lake Superior I: Empirical analysis of past performance

    Science.gov (United States)

    Johnson, Melissa J.; Hansen, Michael J.; Seider, Michael J.

    2015-01-01

    The Gull Island Shoal Refuge was created in 1976 in response to overfishing of the Lake Trout Salvelinus namaycush population in the Apostle Islands region of western Lake Superior. Our objective was to evaluate effectiveness of the refuge by determining whether Lake Trout abundance, growth, maturity, and mortality differed inside and outside the refuge. We compared abundance of wild and stocked fish captured inside and outside the refuge during spring large-mesh gill-net and summer graded-mesh gill-net surveys. We compared growth and mortality during four periods corresponding to four generations of wild Lake Trout, including the last generation that hatched before the refuge was instituted (sampled in 1981–1984) and three generations that were protected by the refuge (sampled in 1985–1992, 1993–2000, and 2001–2010). Maturity of wild fish inside and outside the refuge was compared only for the latter period (2001–2010) because maturity was not assessed earlier. After the refuge was created, wild Lake Trout abundance increased and stocked Lake Trout abundance decreased. Wild adults and juveniles were more abundant inside than outside the refuge, and stocked adults were less abundant inside than outside the refuge. Growth of wild fish did not differ inside versus outside the refuge before 2001, but wild fish grew faster to a shorter asymptotic length inside than outside the refuge during 2001–2010. Wild fish matured at a similar length but an older age inside than outside the refuge during 2001–2010. Survival of wild fish did not differ inside versus outside the refuge before 1993, but mortality was lower inside than outside the refuge during later periods (1993–2000 and 2001–2010). We conclude that the Gull Island Shoal Refuge enhanced the population growth of wild Lake Trout in the Apostle Islands region and should be retained in the future to sustain conditions that favor population growth.

  9. Intra-strain dioxin sensitivity and morphometric effects in swim-up rainbow trout (Oncorhynchus mykiss)

    Science.gov (United States)

    Carvalho, Paulo S. M.; Noltie, Douglas B.; Tillitt, D.E.

    2004-01-01

    Inter and intra-specific differences in sensitivity of early life stage salmonids to 2,3,7,8-TCDD exposure have been reported, but intra-strain differences have not been found in the literature. Our results indicate that intra-strain variability in terms of embryo mortality (LD50) is small in Eagle Lake strain of rainbow trout, LD50 values ranging from 285 to 457 pg TCDD egg g−1. These results confirm Eagle Lake as a less sensitive strain within rainbow trout, and do not indicate overlap with reported LD50 values for brook or lake trout. Our results also demonstrate that although generalized edema in regions including the yolk-sac are frequently associated with mortality following dioxin exposure, not all edematous fish die. We detected dose-dependent decreases in cranial length, eye diameter, mass, and total length (P<0.05) in viable swim-up rainbow trout. These effects are presumed to indicate more subtle dose-dependent disruptions of the viteline vein vasculature and, therefore, in access to energy sources. A tendency for dose-dependent decrease in liver glycogen reserves concurred with previous results on salmonids and with the well described TCDD-induced alterations in intermediate metabolism of rats and chicken embryos (wasting syndrome). This syndrome could be contributing to the reduced growth that we observed.

  10. Study of Some Morphological Characters of Three Trout Breed Farmed in Salmonid Exploitations from Moldova

    Directory of Open Access Journals (Sweden)

    Cătălin Emilian Nistor

    2014-05-01

    Full Text Available Study of morphological characters at fish by means of biometry is a frequently utilized method and consists in determining the variability of characters in groups of individuals, by direct measurement, weighting and statistical processing of obtained data. Effectuation of body measurements and weighting is used to determine the increase in length of fish and to evaluate the general physiological condition. Brook trout, rainbow trout, and brown trout were the object of the current study by analyzing of 50 individuals, 10 individuals in each batch (F1, F2, C1 C2 and I1, from two trout farms from Moldova. After processing the obtained data were calculated the most representative indexes and maintenance coefficients. The obtained values were between 3.49 at batch F1 and 3.94 at batch I1 for profile index; 1.5 at batch I1 and 1.75 at batch F1 for Fulton coefficient; 1.47 at batch F2 and 1.6 at batch I1 for Kiselev index; 41.36 for batch F1 and 47.94 at batch C2 for thickness index; 19.94 C1 batch and 22.08 at F1 batch for fleshy index I, and 19.05 C2 batch and 21.2 at I1 batch for fleshy index II. Having in view the obtained results we can conclude that the analyzed fishes had a good state of maintenance.

  11. Trout in the Classroom

    Science.gov (United States)

    Heath, Thomas

    2014-05-01

    Trout in the Classroom (TIC) is a conservation-oriented environmental education program for elementary, middle, and high school students. During the year each teacher tailors the program to fit his or her curricular needs. Therefore, each TIC program is unique. TIC has interdisciplinary applications in science, social studies, mathematics, language arts, fine arts, and physical education. In the program, students and teachers raise trout from fertilized eggs supplied by Virginia Department of Game and Inland Fisheries (VGIF) hatcheries, in aquariums equipped with special chillers designed to keep the water near 50 degrees F. The students make daily temperature measurements, and monitor pH, dissolved oxygen, conductivity, and ammonia levels. They record their data, plot trends, and make sure that the water quality is sufficient to support trout development. The fingerlings, which hatch in late October, are almost an inch and a half long by mid-January. And towards the end of the school year, students will release the fry into VGIF approved watersheds. TIC programs have been in place all across the country for more than 20 years, and are the result of numerous collaborations between teachers, volunteers, government agencies, and local organizations like Trout Unlimited. The programs were designed specifically for teachers who wanted to incorporate more environmental education into their curriculum. While the immediate goal of Trout in the Classroom is to increase student knowledge of water quality and cold water conservation, its long-term goal is to reconnect an increasingly urbanized population of youth to the system of streams, rivers, and watersheds that sustain them. Successful programs have helped: connect students to their local environments and their local watersheds; teach about watershed health and water quality, and; get students to care about fish and the environment. In Virginia, the TIC program is now in its 8th year. Over the past year, the program

  12. Environmental and Water Quality Operational Studies. Bibliography of Effects of Commercial Navigation Traffic in Large Waterways

    Science.gov (United States)

    1987-04-01

    aossage Physical force 12. launders Z1975) predicted ehio-Senerated bow-wave height (H) in deip vater vith the following equatiov: -kv (I/I) 0 ( V2 /2g...Ventilatory and Cough Frequencies in the Bluegill Lepomi8 maehrochirus and Brook Trout Salvelinus fonti- naZis ," Environmental Pollution Agency, Vol 34, pp

  13. A survey of fishes of the McCormick Forest.

    Science.gov (United States)

    Ronald A. Raisanen; J. Kirwin Werner

    1977-01-01

    The four drainage systems of the Cyrus H. McCormick Experimental Forest were surveyed from May through October, 1975 to determine the distribution and relative abundance of fish. More than 2,500 fish were collected. Game species, such as brook trout (Salvelinus fontinalis) large mouth bass (Micropterus salmoides), smallmouth bass (Micropterus dolomieui), and northern...

  14. Influence of landscape geomorphology on large wood jams and salmonids in an old-growth river of Upper Michigan

    Science.gov (United States)

    Arthur E. L. Morris; P. Charles Goebel; Lance R. Williams; Brian J. Palik

    2006-01-01

    We investigated the structure of large wood jams (LWJ) and their use by brook trout (Salvelinus fontinalis Mitchill) and other fish in four geomorphically-distinct sections of the Little Carp River, a small river flowing through an uncut, old-growth, northern hardwood-conifer forest along the south shore of Lake Superior, Upper Michigan. We...

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

    NARCIS (Netherlands)

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

    2003-01-01

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

  16. 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

  17. Genetic evaluation of a Great Lakes lake trout hatchery program

    Science.gov (United States)

    Page, K.S.; Scribner, K.T.; Bast, D.; Holey, M.E.; Burnham-Curtis, M. K.

    2005-01-01

    Efforts over several decades to restore lake trout Salvelinus namaycush in U.S. waters of the upper Great Lakes have emphasized the stocking of juveniles from each of six hatchery broodstocks. Retention of genetic diversity across all offspring life history stages throughout the hatchery system has been an important component of the restoration hatchery and stocking program. Different stages of the lake trout hatchery program were examined to determine how effective hatchery practices have been in minimizing the loss of genetic diversity in broodstock adults and in progeny stocked. Microsatellite loci were used to estimate allele frequencies, measures of genetic diversity, and relatedness for wild source populations, hatchery broodstocks, and juveniles. We also estimated the effective number of breeders for each broodstock. Hatchery records were used to track destinations of fertilized eggs from all spawning dates to determine whether adult contributions to stocking programs were proportional to reproductive effort. Overall, management goals of maintaining genetic diversity were met across all stages of the hatchery program; however, we identified key areas where changes in mating regimes and in the distribution of fertilized gametes and juveniles could be improved. Estimates of effective breeding population size (Nb) were 9-41% of the total number of adults spawned. Low estimates of Nb were primarily attributed to spawning practices, including the pooling of gametes from multiple males and females and the reuse of males. Nonrandom selection and distribution of fertilized eggs before stocking accentuated declines in effective breeding population size and increased levels of relatedness of juveniles distributed to different rearing facilities and stocking locales. Adoption of guidelines that decrease adult reproductive variance and promote more equitable reproductive contributions of broodstock adults to juveniles would further enhance management goals of

  18. 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.

  19. 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

  20. Seasonal temperature and precipitation regulate brook trout young-of-the-year abundance and population dynamics

    Science.gov (United States)

    Kanno, Yoichiro; Pregler, Kasey C.; Hitt, Nathaniel P.; Letcher, Benjamin H.; Hocking, Daniel; Wofford, John E.B.

    2015-01-01

    Abundance of the young-of-the-year (YOY) fish can vary greatly among years and it may be driven by several key biological processes (i.e. adult spawning, egg survival and fry survival) that span several months. However, the relative influence of seasonal weather patterns on YOY abundance is poorly understood.

  1. Concentration of heavy metals in brook trout in comparison to aquatic plants and sediments

    Energy Technology Data Exchange (ETDEWEB)

    Abo-Rady, M.D.

    1983-01-01

    From 1974 to 1977 the heavy metal content of river water, fishes (Salmo trutta fario), three aquatic plants (Cladophora glomerata, Potamogeton pectinatus, Zannichellia palustris), one river-bank plant (Phalaris arundinacea), and sediments (clay fraction) taken from the River Leine, up and downstream of Goettingen, were determined. Galvanic-bath sewage containing heavy metals caused an increase (11-60%) in the concentration of nine elements in the water. The average level of heavy metals in the river water corresponded to that of the Ems, Elbe and Weser, but was lower than that of the Neckar, Rhine and Danube. It was also below the European Community Guidelines (1975) on the quality of water used for the artificial recharging of ground water. River water upstream of the city has been used for this recharging for many years. There is a good correlation between the metal content in the investigated samples and in the water. In the muscles, only Cd, Co and Mn, in the liver Cd, Co, Cr. Hg, Mn and Zn, and in the total fish Cd, Co, Cr, Cu and Zn had increased significantly. In contrast to all other elements, Cr shows the highest concentration in the muscles. A previous accumulation of Cr in the liver is not a prerequisite for the accumulation in the muscles. Mercury shows the highest accumulation in the muscles, apparently because of the high retention rate of this element. Muscles also are a good monitor for this element. The impact of heavy metals on the Leine water was reflected in aquatic plants, which showed an increase in concentration up to 95-fold (according to metal or plant) - but not in river-bank plants. C. glomerata has the remarkable capability of accumulating all ten elements. Since P. arundinacea cannot reflect the different load of heavy metals it is therefore less suitable as a biological monitor for these metals.

  2. Response of a Brook Trout Population and Instream Habitat to a Catastrophic Flood and Debris Flow

    Science.gov (United States)

    Criag N. Roghair; C. Andrew Dolloff; Martin K. Underwood

    2002-01-01

    In June 1995, a massive flood and debris flow impacted fish and habitat along the lower 1.9 km of the Staunton River, a headwater stream located in Shenandoah National Park, Virginia. In the area affected by debris flow, the stream bed was scoured and new substrate materials were deposited, trees were removed from a 30-m-wide band in the riparian area, and all fish...

  3. Changes in stable isotope composition in Lake Michigan trout ...

    Science.gov (United States)

    Researchers have frequently sought to use environmental archives of sediment, peat and glacial ice to try and assess historical trends in atmospheric mercury (Hg) deposition to aquatic ecosystems. While this information is valuable in the context of identifying temporal source trends, these types of assessments cannot account for likely changes in bioavailability of Hg sources that are tied to the formation of methylmercury (MeHg) and accumulation in fish tissues. For this study we propose the use of long-term fish archives and Hg stable isotope determination as an improved means to relate temporal changes in fish Hg levels to varying Hg sources in the Great Lakes. For this study we acquired 180 archived fish composites from Lake Michigan over a 40-year time period (1975 to 2014) from the Great Lakes Fish Monitoring and Surveillance Program, which were analyzed for their total Hg content and Hg isotope abundances. The results reveal that Hg sources to Lake Michigan trout (Salvelinus namaycush) have encountered considerable changes as well as a large shift in the food web trophic position as a result of the introduction of several invasive species, especially the recent invasion of dreissenid mussels. Total Hg concentrations span a large range (1,600 to 150 ng g-1) and exhibit large variations from 1975 to 1985. Ä199Hg signatures similarly exhibit large variation (3.2 to 6.9‰) until 1985, followed by less variation through the end of the data record in 2014.

  4. 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...

  5. 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.

  6. 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

  7. Species replacement by a nonnative salmonid alters ecosystem function by reducing prey subsidies that support riparian spiders

    Science.gov (United States)

    Benjamin, J.R.; Fausch, K.D.; Baxter, C.V.

    2011-01-01

    Replacement of a native species by a nonnative can have strong effects on ecosystem function, such as altering nutrient cycling or disturbance frequency. Replacements may cause shifts in ecosystem function because nonnatives establish at different biomass, or because they differ from native species in traits like foraging behavior. However, no studies have compared effects of wholesale replacement of a native by a nonnative species on subsidies that support consumers in adjacent habitats, nor quantified the magnitude of these effects. We examined whether streams invaded by nonnative brook trout (Salvelinus fontinalis) in two regions of the Rocky Mountains, USA, produced fewer emerging adult aquatic insects compared to paired streams with native cutthroat trout (Oncorhynchus clarkii), and whether riparian spiders that depend on these prey were less abundant along streams with lower total insect emergence. As predicted, emergence density was 36% lower from streams with the nonnative fish. Biomass of brook trout was higher than the cutthroat trout they replaced, but even after accounting for this difference, emergence was 24% lower from brook trout streams. More riparian spiders were counted along streams with greater total emergence across the water surface. Based on these results, we predicted that brook trout replacement would result in 6-20% fewer spiders in the two regions. When brook trout replace cutthroat trout, they reduce cross-habitat resource subsidies and alter ecosystem function in stream-riparian food webs, not only owing to increased biomass but also because traits apparently differ from native cutthroat trout. ?? 2011 Springer-Verlag.

  8. 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.

  9. VT Foote Brook Natural Channel Design Restoration 2003

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The Foote Brook, located in Johnson, Vermont, is known to biologists and anglers as a high quality stream with significant natural reproduction of...

  10. VT Foote Brook Natural Channel Design Restoration 2001-2002

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The Foote Brook, located in Johnson, Vermont, is known to biologists and anglers as a high quality stream with significant natural reproduction of...

  11. Lake trout otolith chronologies as multidecadal indicators of high-latitude freshwater ecosystems

    Science.gov (United States)

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

    2013-01-01

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

  12. 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

  13. (Salmo trutta macrostigma) and Farmed Rainbow trout

    African Journals Online (AJOL)

    Userrr

    2013-04-06

    Apr 6, 2013 ... Abstract. The purpose of this study was to compare the fatty acid and proximate composition of two commercially exploited trout species (wild brown trout (WBT) and farmed rainbow trout (FRT)). The mean crude lipid content in FRT (4.3%) was significantly higher than that in WBT (2.7%). Total saturated fatty.

  14. Patterns of hybridization of nonnative cutthroat trout and hatchery rainbow trout with native redband trout in the Boise River, Idaho

    Science.gov (United States)

    Neville, Helen M.; Dunham, Jason B.

    2011-01-01

    Hybridization is one of the greatest threats to native fishes. Threats from hybridization are particularly important for native trout species as stocking of nonnative trout has been widespread within the ranges of native species, thus increasing the potential for hybridization. While many studies have documented hybridization between native cutthroat trout Oncorhynchus clarkii and nonnative rainbow trout O. mykiss, fewer have focused on this issue in native rainbow trout despite widespread threats from introductions of both nonnative cutthroat trout and hatchery rainbow trout. Here, we describe the current genetic (i.e., hybridization) status of native redband trout O. mykiss gairdneri populations in the upper Boise River, Idaho. Interspecific hybridization was widespread (detected at 14 of the 41 sampled locations), but high levels of hybridization between nonnative cutthroat trout and redband trout were detected in only a few streams. Intraspecific hybridization was considerably more widespread (almost 40% of sampled locations), and several local populations of native redband trout have been almost completely replaced with hatchery coastal rainbow trout O. mykiss irideus; other populations exist as hybrid swarms, some are in the process of being actively invaded, and some are maintaining genetic characteristics of native populations. The persistence of some redband trout populations with high genetic integrity provides some opportunity to conserve native genomes, but our findings also highlight the complex decisions facing managers today. Effective management strategies in this system may include analysis of the specific attributes of each site and population to evaluate the relative risks posed by isolation versus maintaining connectivity, identifying potential sites for control or eradication of nonnative trout, and long-term monitoring of the genetic integrity of remaining redband trout populations to track changes in their status.

  15. Phylogenetic analysis of the Pacific cutthroat trout (Oncorhynchus clarki ssp.: Salmonidae) based on partial mtDNA ND4 sequences: a closer look at the highly fragmented inland species.

    Science.gov (United States)

    Wilson, Wade D; Turner, Thomas F

    2009-08-01

    The genus Oncorhynchus includes Pacific salmon and trout (anadromous and land-locked) species of the western United States and Mexico. All species and subspecies in this group are threatened, endangered, sensitive, or species of conservation concern in portions of their native ranges. To examine the relationships of the species within Oncorhynchus we sequenced a 768 bp fragment of the protein-encoding ND4 mtDNA region. We included all six recognized subspecies of O. clarki (cutthroat trout), O. gilaegilae (Gila trout) and O. g. apache (Apache trout). Gene trees from likelihood and Bayesian phylogenetic analyses revealed that Salvelinus was the sister group to Oncorhynchus, and as expected based on previous studies, O. clarki was sister to a clade that consisted of O. mykiss plus O. g. gilae and O. g. apache. Within the cutthroat clade (O. clarki), the coastal form O. c. clarki was basal with the Rio Grande cutthroat (O. c. virginalis) most derived. Divergence dating based on a fossil calibration molecular clock showed the oldest clade (mean node age) was O. masou ssp., which diverged roughly 7.6 MYA. Highest probability density intervals for divergence of O. masou overlapped with divergence (6.3 MYA) of Pacific salmon clades ((O. gorbuscha + O. nerka) and (O. tshawytscha + O. kisutch)). The Pacific trout clade ((O. mykiss + O. gilae ssp.) + (O. clarki ssp.)) diverged from the Pacific salmon around 6.3 MYA, with most of the diversification within the O. clarki clade occurring in the last 1 MY.

  16. Cleanth Brooks at the United States Air Force Academy April 11-12, 1978,

    Science.gov (United States)

    1980-01-01

    April 1966. The Writer and His Community. Glasgow: Jackson , 1968. The Twenty-First W. P. Fer Memorial Lecture delivered in the University of Glasgow...Brooks & Warren. N. Y.: Crofts 119431. The Correspondence of Thomas Percy . General Editors, David Nichol Smith & Brooks. 5 vols. Baton Rouge: LSU Press...1944-57. Brooks edited vol. 11, The Correspondence of Thomas Percy and Richard Farmer [19461. Understanding Drama. By Brooks & Robert B. Heilman. N

  17. Aerospace medicine at Brooks AFB, TX: hail and farewell.

    Science.gov (United States)

    Nunneley, Sarah A; Webb, James T

    2011-05-01

    With the impending termination of USAF operations at Brooks Air Force Base (AFB) in San Antonio, TX, it is time to consider its historic role in Aerospace Medicine. The base was established in 1917 as a flight training center for the U.S. Army Air Service and in 1926 became home to its School of Aviation Medicine. The school moved to San Antonio's Randolph Field in 1931, but in 1959 it returned to Brooks where it occupied new facilities to support its role as a national center for U.S. Air Force aerospace medicine, including teaching, clinical medicine, and research. The mission was then expanded to encompass support of U.S. military and civilian space programs. With the abrupt termination of the military space program in 1969, research at Brooks focused on clinical aviation medicine and support of advanced military aircraft while continuing close cooperation with NASA in support of orbital spaceflight and the journey to the Moon. Reorganization in the 1990s assigned all research functions at Brooks to the Human Systems Division and its successors, leaving to USAFSAM the missions related to clinical work and teaching. In 2002 the USAF and the city of San Antonio implemented shared operation of Brooks as a "City-Base" in the hope of deflecting threatened closure. Nevertheless, under continuing pressure to consolidate military facilities in the United States, the 2005 Base Closure and Realignment Commission ordered Brooks closed by 2011, with its aerospace medicine functions relocated to new facilities at Wright-Patterson AFB in Dayton, OH.

  18. 77 FR 35054 - Donald Brooks Reece II, M.D.; Dismissal of Proceeding

    Science.gov (United States)

    2012-06-12

    ... Enforcement Administration Donald Brooks Reece II, M.D.; Dismissal of Proceeding On November 19, 2010, the... Order to Show Cause to Donald Brooks Reece II, M.D. (Respondent), of Morehead City, N.C. The Order... Donald Brooks Reece II, M.D., be, and it hereby is, dismissed. This Order is effective immediately. Dated...

  19. Clarification to Brook and Willoughby (2016).

    Science.gov (United States)

    2016-07-01

    Reports an error in "Social anxiety and alcohol use across the university years: Adaptive and maladaptive groups" by Christina A. Brook and Teena Willoughby (Developmental Psychology, 2016[May], Vol 52[5], 835-845). In the article, Figures 1 and 2 and Tables 1, 2, 3, and 4 were inadvertently designated as supplemental material. The figures and tables are present in the erratum. (The following abstract of the original article appeared in record 2016-13161-001.) University/college can be a challenging time as students face developmental tasks such as building new social networks and achieving academically. Social anxiety may be disadvantageous in this setting given that social situations often include drinking and individuals with social anxiety tend to self-medicate through alcohol use. However, findings are mixed as to whether the association between social anxiety and alcohol use is positive or negative. To clarify the nature of this association, we used a person-centered longitudinal analysis to identify student groups based on levels of social anxiety symptoms and alcohol consumption. Undergraduates (N = 1132, 70.5% female, Mage = 19.06 at Time 1) enrolled in university completed a survey assessing social anxiety and alcohol use over 3 years, and psychosocial functioning and emotion coping behaviors at Time 1. Two out of 5 groups were identified with higher levels of social anxiety, 1 with moderately low alcohol use, and the other with moderately high alcohol use. Both groups reported higher levels of general anxiety, depressive symptoms, behavioral inhibition, emotional reactivity, daily hassles, and lower levels of social ties at Time 1 than the 3 groups with lower levels of social anxiety. Furthermore, the social anxiety-alcohol use group reported significantly lower academic grades and was more likely to endorse problematic emotion coping behaviors (e.g., self-injury) than the social anxiety-low alcohol use group. These results not only help explain the

  20. Copper uptake across rainbow trout gills: mechanisms of apical entry

    DEFF Research Database (Denmark)

    Grosell, Martin Hautopp; Wood, C. M.

    2002-01-01

    Copper, Homeostasis, sodium uptake, copper/sodium interactions, gill, rainbow trout, Oncorhynchus mykiss......Copper, Homeostasis, sodium uptake, copper/sodium interactions, gill, rainbow trout, Oncorhynchus mykiss...

  1. Patterns of streamwater acidity in Lye Brook Wilderness, Vermont, USA

    Science.gov (United States)

    John L. Campbell; Christopher Eagar; William H. McDowell

    2002-01-01

    Under the United States Clean Air Act Amendments of 1977, a class I designation safeguards wilderness areas from the negative effects of new sources of air pollution. We monitored streamwater chemistry in the class I Lye Brook Wilderness in southwestern Vermont from May 1994 through August 1995. Stream samples were collected biweekly at nine sampling locations...

  2. Feasibility of target communities in a Dutch brook valley system

    NARCIS (Netherlands)

    Prins, AH; Bekker, RM

    As a reaction to the ongoing deterioration of nature conservation interest in The Netherlands, an offensive nature strategy was formulated in the 1990 Nature Policy Plan. In this Plan, target communities and target plant species are mentioned. For the 'Drentse A brook valley system', target

  3. Building the Engaged Campus: An Interview with John Brooks Slaughter.

    Science.gov (United States)

    Maeda, Donna

    1999-01-01

    Interview with John Brooks Slaughter, recent president of Occidental College, focuses on his leadership during a period when the college dramatically increased its minority enrollment, recruited an impressively diverse faculty, and launched various community outreach programs. Explores Slaughter's views concerning diversity as part of a college's…

  4. If Arctic charr Salvelinus alpinus is “the most diverse vertebrate,” what is the lake charr Salvelinus namaycush?

    Science.gov (United States)

    Muir, Andrew M.; Hansen, Michael J.; Bronte, Charles R.; Krueger, Charles C.

    2016-01-01

    Teleost fishes are prominent vertebrate models of evolution, illustrated among old-world radiations by the Cichlidae of East African Great Lakes and new-world radiations by the circumpolar Arctic charr Salvelinus alpinus. Herein, we describe variation in lake charr S. namaycush morphology, life history, physiology, and ecology, as another example of radiation. The lake charr is restricted to northern North America, where it originated from glacial refugia and diversified in large lakes. Shallow and deepwater morphs arose in multiple lakes, with a large-bodied shallow-water ‘lean’ morph in shallow inshore depths, a small-bodied mid-water ‘humper’ morph on offshore shoals or banks, and a large-bodied deep-water ‘siscowet’ morph at depths > 100 m. Eye position, gape size, and gillraker length and spacing adapted for feeding on different-sized prey, with piscivorous morphs (leans and siscowets) reaching larger asymptotic size than invertivorous morphs (humpers). Lean morphs are light in color, whereas deepwater morphs are drab and dark, although the pattern is reversed in dark tannic lakes. Morphs shift from benthic to pelagic feeding at a length of 400–490-mm. Phenotypic differences in locomotion, buoyancy, and lipid metabolism evolved into different mechanisms for buoyancy regulation, with lean morphs relying on hydrodynamic lift and siscowet morphs relying on hydrostatic lift. We suggest that the Salvelinus genus, rather than the species S. alpinus, is a diverse genus that should be the subject of comparative studies of processes causing divergence and adaptation among member species that may lead to a more complete evolutionary conceptual model.

  5. Use of an annular chamber for testing thermal preference of westslope cutthroat trout and rainbow trout

    Science.gov (United States)

    McMahon, T.E.; Bear, E.A.; Zale, A.V.

    2008-01-01

    Remaining populations of westslope cutthroat trout (Oncorhynchus clarkii lewisi) in western North America are primarily confined to cold headwaters whereas nonnative rainbow trout (Oncorhynchus mykiss) predominate in warmer, lower elevation stream sections historically occupied by westslope cutthroat trout. We tested whether differing thermal preferences could account for the spatial segregation observed in the field. Thermal preferences of age-1 westslope cutthroat trout and rainbow trout (125 to 150 mm total length) were assessed in the laboratory using a modified annular preference chamber at acclimation temperatures of 10, 12, 14, and 16??C Final preferred temperature of westslope cutthroat trout (14.9??C) was similar to that of rainbow trout (14.8??C) when tested in a thermal gradient of 11-17??C The high degree of overlap in thermal preference indicates the two species have similar thermal niches and a high potential for competition. We suggest several modifications to the annular preference chamber to improve performance in future studies.

  6. Trout Creek Mountain project, Oregon

    OpenAIRE

    Hatfield, Doc; Hatfield, Connie

    1995-01-01

    The Trout Creek Mountain experience is an example of how the land and the people can win by building bridges of understanding and common interest between concerned constituencies. Love of the land, its natural resources, and realization of a need for changing grazing practices to reverse the degradation of riparian areas were the common interests that caused environmentalists, ranchers, the BLM, the Oregon Department of Fish and Wildlife, and the U.S. Fish and Wildlife Service to work togethe...

  7. Farming of Freshwater Rainbow Trout in Denmark

    DEFF Research Database (Denmark)

    Jokumsen, Alfred; Svendsen, Lars Moeslund

    Textbook on Farming of Freshwater Rainbow Trout in Denmark. Danish edition with the title: Opdræt af regnbueørred i Danmark......Textbook on Farming of Freshwater Rainbow Trout in Denmark. Danish edition with the title: Opdræt af regnbueørred i Danmark...

  8. Conservation status of Colorado River cutthroat trout

    Science.gov (United States)

    Michael K. Young; R. Nick Schmal; Thomas W. Kohley; Victoria G. Leonard

    1996-01-01

    Though biologists recognize that populations of Colorado River cutthroat trout have declined, the magnitude of the loss remains unquantified. We obtained information from state and federal biologists and from state databases to determine the current distribution and status of populations of Colorado River cutthroat trout. Recent population extinctions have been...

  9. Bath vaccination of rainbow trout against yersiniosis

    DEFF Research Database (Denmark)

    Raida, Martin Kristian; Buchmann, Kurt

    2007-01-01

    Studies have been conducted on the temperature-dependent effect of bath vaccination of rainbow trout against Yersinia ruckeri O1. Protection of rainbow trout fry against challenge, following bath vaccination with a bacterin of Yersinia ruckeri O1, the bacterial pathogen causing enteric red mouth...... disease (ERM), was investigated at 5, 15 and 25° C. Rainbow trout fry were kept at controlled temperatures for two month before they were immersed in a commercial Yersinia ruckeri O1 bacterin for 10 minutes. Control groups were sham vaccinated using pure water. Fish were challenged with Yersinia ruckeri O......1 one and two month post vaccination at the three temperatures. Protection of vaccinated fish was seen one and two month post vaccination in rainbow trout reared at 15° C. There was no effect of vaccination in rainbow trout reared at 5 and 25° C. Spleen tissue was sampled from 5 vaccinated and 5...

  10. Mujeres malditas pintadas de gris : el arte de Romaine Brooks

    Directory of Open Access Journals (Sweden)

    Amparo Serrano de Haro

    1994-01-01

    Full Text Available A pesar de su morbosa elegancia y fatídica sensualidad, los retratos de Romaine Brooks, grises como la nostalgia, son aceptados y considerados dignos de atención crítica desde hace muy poco tiempo. Romaine Brooks,norteamericana nacida en Roma en 1874, cuyas pinturas gozaron de una gran popularidad en el París de principios de siglo XX, fue prácticamente olvidada a partir de los años treinta. La donación de buena parte de su obra al Museo Nacional de Washington a fines de los años 60 y la exposición antológica de su obra en 1971 (un año después de su muerte, iniciaron lo que sería un proceso de recuperación de su figura y su pintura.

  11. 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.

  12. Do stocked hatchery-reared juveniles ecologically suppress wild juveniles in Salvelinus leucomaenis?

    Science.gov (United States)

    Nakamura, T; Doi, T

    2014-05-01

    The dominancy of semi-wild and hatchery-reared white-spotted charr Salvelinus leucomaenis juveniles was evaluated using pair-wise enclosure tests and field stocking tests. The semi-wild S. leucomaenis originated in a hatchery, being stocked into the test stream as eyed-eggs. In the pair-wise enclosure test, the semi-wild S. leucomaenis dominated the hatchery S. leucomaenis that were of a similar standard length (L(S) ). The semi-wild S. leucomaenis were subordinate to hatchery S. leucomaenis that were > 11% larger in LS . In the field stocking test, the abundance and growth of semi-wild S. leucomaenis was decreased in the presence of larger hatchery S. leucomaenis (14% larger LS ). Taken together, these results suggest that larger hatchery S. leucomaenis ecologically suppress the smaller semi-wild S. leucomaenis. Salvelinus leucomaenis juveniles that are stocked with the intention of supplementing natural populations should be hatchery S. leucomaenis used in both tests were genetically similar individuals, suggesting that the differences are due to the early rearing environment of either a natural stream or hatchery. The hatchery S. leucomaenis have lower levels of aggression as a result of selection in the hatchery rearing environment. Rearing in a natural stream from the eyed-egg stage is likely to increase their lowered aggression. Journal of Fish Biology © 2014 The Fisheries Society of the British Isles.

  13. 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.

  14. Investigating the extent of parallelism in morphological and genomic divergence among lake trout ecotypes in Lake Superior.

    Science.gov (United States)

    Perreault-Payette, Alysse; Muir, Andrew M; Goetz, Frederick; Perrier, Charles; Normandeau, Eric; Sirois, Pascal; Bernatchez, Louis

    2017-03-01

    Understanding the emergence of species through the process of ecological speciation is a central question in evolutionary biology which also has implications for conservation and management. Lake trout (Salvelinus namaycush) is renowned for the occurrence of different ecotypes linked to resource and habitat use throughout North America. We aimed to unravel the fine genetic structure of the four lake trout ecotypes in Lake Superior. A total of 486 individuals from four sites were genotyped at 6822 filtered SNPs using RADseq technology. Our results revealed different extent of morphological and genetic differentiation within the different sites. Overall, genetic differentiation was weak but significant and was on average three times higher between sites (mean FST  = 0.016) than between ecotypes within sites (mean FST  = 0.005) indicating higher level of gene flow or a more recent shared ancestor between ecotypes within each site than between populations of the same ecotype. Evidence of divergent selection was also found between ecotypes and/or in association with morphological variation. Outlier loci found in genes related to lipid metabolism and visual acuity were of particular interest in this context of ecotypic divergence. However, we did not find clear indication of parallelism at the genomic level, despite the presence of phenotypic parallelism among some ecotypes from different sampling sites. Overall, the occurrence of different levels of both genomic and phenotypic differentiation between ecotypes within each site with several differentiated loci linked to relevant biological functions supports the presence of a continuum of divergence in lake trout. © 2017 John Wiley & Sons Ltd.

  15. Changing numbers of spawning cutthroat trout in tributary streams of Yellowstone Lake and estimates of grizzly bears visiting streams from DNA

    Science.gov (United States)

    Haroldson, M.A.; Gunther, K.A.; Reinhart, Daniel P.; Podruzny, S.R.; Cegelski, C.; Waits, L.; Wyman, T.C.; Smith, J.

    2005-01-01

    Spawning Yellowstone cutthroat trout (Oncorhynchus clarki) provide a source of highly digestible energy for grizzly bears (Ursus arctos) that visit tributary streams to Yellowstone Lake during the spring and early summer. During 1985–87, research documented grizzly bears fishing on 61% of the 124 tributary streams to the lake. Using track measurements, it was estimated that a minimum of 44 grizzly bears fished those streams annually. During 1994, non-native lake trout (Salvelinus namaycush) were discovered in Yellowstone Lake. Lake trout are efficient predators and have the potential to reduce the native cutthroat population and negatively impact terrestrial predators that use cutthroat trout as a food resource. In 1997, we began sampling a subset of streams (n = 25) from areas of Yellowstone Lake surveyed during the previous study to determine if changes in spawner numbers or bear use had occurred. Comparisons of peak numbers and duration suggested a considerable decline between study periods in streams in the West Thumb area of the lake. The apparent decline may be due to predation by lake trout. Indices of bear use also declined on West Thumb area streams. We used DNA from hair collected near spawning streams to estimate the minimum number of bears visiting the vicinity of spawning streams. Seventy-four individual bears were identified from 429 hair samples. The annual number of individuals detected ranged from 15 in 1997 to 33 in 2000. Seventy percent of genotypes identified were represented by more than 1 sample, but only 31% of bears were documented more than 1 year of the study. Sixty-two (84%) bears were only documented in 1 segment of the lake, whereas 12 (16%) were found in 2–3 lake segments. Twenty-seven bears were identified from hair collected at multiple streams. One bear was identified on 6 streams in 2 segments of the lake and during 3 years of the study. We used encounter histories derived from DNA and the Jolly-Seber procedure in Program MARK

  16. Optimum temperature of a northern population of Arctic charr (Salvelinus alpinus) using heart rate Arrhenius breakpoint analysis

    DEFF Research Database (Denmark)

    Hansen, Aslak Kappel; Byriel, David Bille; R. Jensen, Mads

    2017-01-01

    the optimum temperature (Topt) of nine adult Arctic charr (Salvelinus alpinus) from Qeqertarsuaq, Greenland, using maximum heart rate (fHmax) for investigating the optimal temperatures for activity. The Arrhenius breakpoint of maximum heart rate measurements occurred between 5.9 and 8.3 °C (average = 7.5 °C...

  17. 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,

  18. Amoxicillin Pulsatile MiddleBrook: APC 111, APC-111, PULSYS-Enhanced Amoxicillin

    National Research Council Canada - National Science Library

    Adis International Limited

    2007-01-01

    MiddleBrook Pharmaceuticals (formerly Advancis Pharmaceutical) is developing an improved version of amoxicillin using its pulsatile oral drug delivery technology, called PULSYS™. Amoxicillin PULSYS...

  19. Keeping things local: Subpopulation N b and N e in a stream network with partial barriers to fish migration

    OpenAIRE

    Whiteley, Andrew R.; Coombs, Jason A.; O'Donnell, Matthew J.; Nislow, Keith H.; Benjamin H Letcher

    2017-01-01

    Abstract For organisms with overlapping generations that occur in metapopulations, uncertainty remains regarding the spatiotemporal scale of inference of estimates of the effective number of breeders ( N ^ b ) and whether these estimates can be used to predict generational N e. We conducted a series of tests of the spatiotemporal scale of inference of estimates of N b in nine consecutive cohorts within a long?term study of brook trout (Salvelinus fontinalis). We also tested a recently develop...

  20. 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

    correlated with lake volume. Our study indicates that the charr population structure became more complex with increasing lake size. Moreover, the population structure seemed to be influenced by lake-water transparency and the presence or absence of three-spined stickleback (Gasterosteus aculeatus)......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...

  1. Metabolomics Approach To Evaluate a Baltic Sea Sourced Diet for Cultured Arctic Char (Salvelinus alpinus L.).

    Science.gov (United States)

    Cheng, Ken; Müllner, Elisabeth; Moazzami, Ali A; Carlberg, Hanna; Brännäs, Eva; Pickova, Jana

    2017-06-21

    Aqua feeds traditionally rely on fishmeal as a protein source, which is costly and unsustainable. A new feed was formulated in the study with Baltic Sea sourced decontaminated fishmeal, Mytilus edulis and Saccharomyces cerevisiae, and given to Arctic char (Salvelinus alpinus) for ten months. The diet-induced changes on metabolic profile in fish plasma, liver, and muscle were studied relative to a fishmeal-based standard diet by using a (1)H NMR-based metabolomics approach. Fish fed the test diet had higher content of betaine and lower levels of trimethylamine-N-oxide and aromatic amino acids in plasma or tissues, which were mainly caused by the diet. The metabolomics results are useful to understand the mechanism of lower body mass, smaller Fulton's condition factor, and a tendency of less lipid content observed in fish fed the test diet. Thus, modifications on the dietary levels of these compounds in the feed are needed to achieve better growth performance.

  2. Toxicokinetics of PFOS in rainbow trout

    Data.gov (United States)

    U.S. Environmental Protection Agency — This ScienceHub entry was developed for the published paper: Consoer et al., 2016, Toxicokinetics of perfluorooctane sulfonate in rainow trout (Oncorhynchus mykiss),...

  3. Brooks Range and eastern Alps: a tectonic comparison

    Energy Technology Data Exchange (ETDEWEB)

    Helwig, J.A.

    1985-04-01

    A comparison of the tectonic evolution of the Brooks Range (BR) and the Eastern Alps (EA) reveals a remarkable parallelism. Both of these Mesozoic-Cenozoic orogenic belts are underlain by sialic crust formed in an earlier Paleozoic orogenic cycle. The old basement is revealed in major tectonic windows: the Tauern Fenster (EA) and the Doonerak Window-Schwatka Mountains (BR) - which are unconformably overlapped by transgressive, neritic marine clastic to carbonate successions - the Permo-Triassic through Hochstegenkalk sequence (EA), and the Kekiktuk-Kayak-Lisburne sequence (BR). These successions are passive-margin sequences that pass southward, in palinspastically restored cross sections, to synchronous deep-water facies deposited on ophiolitic basement - Bunderschiefer on Triassic-Jurassic ophiolites (EA) and Kuna facies or Etivluk sequence on upper Paleozoic ophiolites (BR). Onset of subduction-collision is marked by olistostromal facies - Cretaceous wildflysch (EA) and Jura-Cretaceous Okpikruak Formation (BR) - and the development of major flysch-molasse successions in the foreland basins of the collisional fold and thrust belts. Important major contrasts between these two mountain ranges reside in their colliding blocks and their post-orogenic histories. Alpine orogenesis was driven by continent-continent collision, closing out a young, narrow ocean, whereas Brooks Range deformation appears to have originated by arc-continent collision, closing out an older, broad (.)ocean. Younger Cenozoic deformation is extensional and strike-slip in the Eastern Alps, producing disjunctive basins, but Cenozoic deformation in the Brooks Range is diverse and includes compression in the east and extension in the far west.

  4. Linking movement and reproductive history of brook trout to assess habitat connectivity in a heterogeneous stream network

    Science.gov (United States)

    Kanno, Yoichiro; Letcher, Benjamin H.; Coombs, Jason A.; Nislow, Keith H.; Whiteley, Andrew R.

    2013-01-01

    1. Defining functional connectivity between habitats in spatially heterogeneous landscapes is a particular challenge for small-bodied aquatic species. Traditional approaches (e.g. mark–recapture studies) preclude an assessment of animal movement over the life cycle (birth to reproduction), and movement of individuals may not represent the degree of gene movement for fecund species.

  5. Linking movement and reproductive history of brook trout to assess habitat connectivity in a heterogeneous stream network

    Science.gov (United States)

    Yoichiro Kanno; Benjamin H. Letcher; Jason A. Coombs; Keith H. Nislow; Andrew R. Whiteley

    2014-01-01

    Defining functional connectivity between habitats in spatially heterogeneous landscapes is a particular challenge for small-bodied aquatic species. Traditional approaches (e.g. mark-recapture studies) preclude an assessment of animal movement over the life cycle (birth to reproduction), and movement of individuals may not represent the degree of gene movement for...

  6. [Obituary] In memoriam: Mortimer Brooke Meanley, Jr., 1915-2007

    Science.gov (United States)

    Perry, Matthew C.

    2008-01-01

    Mortimer Brooke Meanley, Jr., was born at Riderwood, Baltimore County, Maryland, on 19 January 1915, and died at home in Maine on 19 August 2007. He was always called “Brooke” as an adult. Much of his youth was spent in birding and other natural-history activities, interest he credits to the Boy Scouts and his teachers. These activities directed him toward a professional career in wildlife biology. He was educated at McDonogh High School in Owings Mill, Maryland – at the time a private, semimilitary school for boys – and graduated in 1934.

  7. Brooks/Jackson’s level Cleopatra: production and reception

    Directory of Open Access Journals (Sweden)

    José Roberto O’Shea

    2000-07-01

    Full Text Available The influence which current views on dramatic theory and technique have exercised upon theatrical productions has long been the object of scholarly inquiry. Peter Brook’s The Empty Space (1968; rpt. 1990, for instance, can be a helpful tool in the study of Brook’s own 1978 Royal Shakespeare Company production of Antony and Cleopatra, with Glenda Jackson and Alan Howard in the title roles. The production followed by eight years the now legendary “circus” Midsummer Night’s Dream which Brook had staged for the RSC in 1970, and reviewers were virtually unanimous in praising the production’s innovative, swiftly-paced set.

  8. The Why, What, and Impact of GPA at Oxford Brookes University

    Science.gov (United States)

    Andrews, Matthew

    2016-01-01

    This paper examines the introduction at Oxford Brookes University of a Grade Point Average (GPA) scheme alongside the traditional honours degree classification. It considers the reasons for the introduction of GPA, the way in which the scheme was implemented, and offers an insight into the impact of GPA at Brookes. Finally, the paper considers…

  9. Brown Trout removal effects on short-term survival and movement of Myxobolus cerebralis-resistant rainbow trout

    Science.gov (United States)

    Fetherman, Eric R.; Winkelman, Dana L.; Bailey, Larissa L.; Schisler, George J.; Davies, K.

    2015-01-01

    Following establishment of Myxobolus cerebralis (the parasite responsible for salmonid whirling disease) in Colorado, populations of Rainbow Trout Oncorhynchus mykissexperienced significant declines, whereas Brown Trout Salmo trutta densities increased in many locations across the state, potentially influencing the success of M. cerebralis-resistant Rainbow Trout reintroductions. We examined the effects of Brown Trout removal on the short-term (3-month) survival and movement of two crosses of reintroduced, M. cerebralis-resistant Rainbow Trout in the Cache la Poudre River, Colorado. Radio frequency identification passive integrated transponder tags and antennas were used to track movements of wild Brown Trout and stocked Rainbow Trout in reaches where Brown Trout had or had not been removed. Multistate mark–recapture models were used to estimate tagged fish apparent survival and movement in these sections 3 months following Brown Trout removal. A cross between the German Rainbow Trout and Colorado River Rainbow Trout strains exhibited similar survival and movement probabilities in the reaches, suggesting that the presence of Brown Trout did not affect its survival or movement. However, a cross between the German Rainbow Trout and Harrison Lake Rainbow Trout exhibited less movement from the reach in which Brown Trout had been removed. Despite this, the overall short-term benefits of the removal were equivocal, suggesting that Brown Trout removal may not be beneficial for the reintroduction of Rainbow Trout. Additionally, the logistical constraints of conducting removals in large river systems are substantial and may not be a viable management option in many rivers.

  10. Bull Trout Spawning Surveys: Kootenai National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Bull trout are listed as threatened under the Endangered Species Act and Myrtle Creek was designated as critical habitat for bull trout this year. Myrtle Creek flows...

  11. Microsatellites variation in two different populations of Brown trout (Salmo trutta, morpha fario, Linnaeus, 1758 from Făgăraş Mountains

    Directory of Open Access Journals (Sweden)

    Miad Khalaf

    2015-05-01

    Full Text Available Salmonids are members of the Salmonidae family which includes the subfamily Coregoninae, subfamily Thymallinae and subfamily Salmoninae. This family includes fish of interest for aquaculture and sport fishing. The salmonids from the natural environment on Romanian territory are Salmo trutta fario, Salmo labrax, Salvelinus fontinalis fontinalis, Hucho hucho, and Thymallus thymallus. Gene flow from fishery populations to those in the natural habitat may create substantial problems to natural species which leads to a reduction of inherited genetic diversity and of environment adjustment due to a loss of natural capacity to adapt. Due their characteristics, microsatellites prove themselves usefull in population genetics studies. In our study we analyzed the polymorphism of nine microsatellite loci (BS131, Str60, Str73, Str15, Str543, OmyFGT, Ssa85, Ssa197, Strutta12 in two brown trout population from Făgăraş Mountains. We successfully amplified all microsatellite loci obtaining allele peaks of different sizes. The number of allele ranged beetwen 1 (Str73 and 26 (OmyFGT. The analyzed trout populations show a relatively high degree of genetic diversity, being also characterized by a low level of inbreeding among individuals. This technology has great potential for investigating the genetic diversity of the wild population and, also, might be extended to aquaculture studies.

  12. Biology and management of threatened and endangered western trouts

    Science.gov (United States)

    R. J. Behnke; Mark Zarn

    1976-01-01

    Discusses taxonomy, reasons for decline, life history and ecology, and suggestions for preservation and management of six closely related trouts native to western North America: Colorado River cutthroat, Salmo clarki pleuriticus; greenback trout, S. c. stomias; Lahontan cutthroat, S. c. henshawi; Paiute trout,...

  13. Evaluation of dietary soy sensitivity in snake river cutthroat trout

    Science.gov (United States)

    Hatchery-cultured cutthroat trout fed some commercially available rainbow trout feeds display slow growth and increased mortality. Feed characteristics such as buoyancy and texture alter feed acceptance in some fish species but their effects have not been adequately addressed in cutthroat trout. Th...

  14. Factors influencing the spawning migration of female anadromous brown trout

    DEFF Research Database (Denmark)

    Svendsen, Jon Christian; Koed, Anders; Aarestrup, Kim

    2004-01-01

    Radio telemetry was employed to study movements of adult female anadromous brown trout Salmo trutta (sea trout) during upstream spawning migration and following spawning in a stream with tributaries. Sea trout were monitored by manual tracking and by automatic listening stations. The latter sugge...

  15. Use of microsatellite markers for identification of indigenous brown trout in a geographical region heavily influenced by stocked domesticated trout

    DEFF Research Database (Denmark)

    Fritzner, Niels G.; Møller Hansen, Michael; Madsen, Steffen

    2001-01-01

    Based on estimates of genetic differentiation between populations, assignment tests and analysis of isolation by distance, stocked populations of brown trout Salmo trutta of Funen Island, Denmark, had been genetically affected by domesticated trout, whereas the stocking of wild exogenous trout in...

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

    Science.gov (United States)

    Lisa A. Eby; Olga Helmy; Lisa M. Holsinger; Michael K. Young

    2014-01-01

    Many freshwater fish species are considered vulnerable to stream temperature warming associated with climate change because they are ectothermic, yet there are surprisingly few studies documenting changes in distributions. Streams and rivers in the U.S. Rocky Mountains have been warming for several decades. At the same time these systems have been experiencing an...

  17. Observer error structure in bull trout redd counts in Montana streams: Implications for inference on true redd numbers

    Science.gov (United States)

    Muhlfeld, Clint C.; Taper, Mark L.; Staples, David F.; Shepard, Bradley B.

    2006-01-01

    Despite the widespread use of redd counts to monitor trends in salmonid populations, few studies have evaluated the uncertainties in observed counts. We assessed the variability in redd counts for migratory bull trout Salvelinus confluentus among experienced observers in Lion and Goat creeks, which are tributaries to the Swan River, Montana. We documented substantially lower observer variability in bull trout redd counts than did previous studies. Observer counts ranged from 78% to 107% of our best estimates of true redd numbers in Lion Creek and from 90% to 130% of our best estimates in Goat Creek. Observers made both errors of omission and errors of false identification, and we modeled this combination by use of a binomial probability of detection and a Poisson count distribution of false identifications. Redd detection probabilities were high (mean = 83%) and exhibited no significant variation among observers (SD = 8%). We applied this error structure to annual redd counts in the Swan River basin (1982–2004) to correct for observer error and thus derived more accurate estimates of redd numbers and associated confidence intervals. Our results indicate that bias in redd counts can be reduced if experienced observers are used to conduct annual redd counts. Future studies should assess both sources of observer error to increase the validity of using redd counts for inferring true redd numbers in different basins. This information will help fisheries biologists to more precisely monitor population trends, identify recovery and extinction thresholds for conservation and recovery programs, ascertain and predict how management actions influence distribution and abundance, and examine effects of recovery and restoration activities.

  18. Stony Brook's Graduate Courses in Clear, Vivid, Conversational Communication

    Science.gov (United States)

    Bass, E.

    2011-12-01

    Graduate students in the sciences at Stony Brook University are taking for-credit courses to learn to communicate more effectively about science with people outside their disciplines, including public officials, the press, students, potential funders and employers, colleagues in other fields, and the general public. Five Communicating Science courses are offered; two more will be added in January, 2012. The courses are offered by the School of Journalism and developed by the Center for Communicating Science (CCS). This interdisciplinary center was founded in 2009, with the participation of Alan Alda, the actor, writer, director and longtime advocate for science, who is a Visiting Professor at Stony Brook. At the core of the program are three 1-credit (14-hour) modules that rely on experiential learning, repeated practice and immediate, interactive feedback. In Distilling Your Message, students practice speaking clearly, vividly and conversationally about their work at different levels of complexity and formality to different audiences, using storytelling techniques where appropriate. In Writing for the Public, they extend these skills into writing. In Improvisation for Scientists, the most unconventional of the courses, students play improvisational theater games to help themselves connect more directly, personally and responsively with their audiences. In their first two semesters, the courses are expected to serve about 90 students, taking a total of about 180 credits. Most of the courses have filled quickly, mixing master's and doctoral students from more than a dozen fields, including marine and atmospheric sciences. Three to six credits of Communicating Science courses are required for students in two programs, an MA in Marine Conservation and Policy and an Advanced Certificate in Health Communications. The content and methods of the courses are based largely on lessons learned from evaluations of all-day workshops that CCS has conducted for more than 250

  19. Geological mapping in Doonerak Fenster, Central Brooks Range, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Mull, C.C.; Adams, K.E.; Dillon, J.T.

    1985-04-01

    Mapping of the north flank of the Doonerak fenster has traced the Amawk thrust, the sole fault of the Endicott Mountains allochthon, from the North Fork of the Koyukuk River - Mount Doonerak area eastward for more than 40 km (25 mi) to the east plunge of the Doonerak anticline at Koyuktuvuk Creek near the Dietrich River. Mapping has concentrated on the structural style of the area and on the autochthonous or parautochthonous Carboniferous Lisburne Group, Kayak shale, Kekiktuk Conglomerate - which are present along most of the anticline - and Triassic Karen Creek Sandstone, Triassic Shublik Formation, and Permian-Triassic Sadlerochit Group - which are present only in the west. This Triassic to Mississippian section closely resembles the coeval autochthonous to Parautochthonous Ellesmerian section of the subsurface to the north and in the Brooks Range to the northeast.

  20. Microsatellite analyses of Alameda Creek Rainbow/Steelhead trout

    Science.gov (United States)

    Nielsen, Jennifer L.; Fountain, Monique C.

    1999-01-01

    Microsatellite genetic diversity found in Alameda Creek rainbow trout support a close genetic relationship with coastal trout found in Lagunitas Creek, Marin County, California. No significant genotypic or allelic frequencies associations could be drawn among Alameda Creek trout and fish collected from the four primary rainbow trout hatchery strains in use in California, Whitney, Mount Shasta, Coleman, and Hot Creek strains, indeed, genetic distance analyses (δμ2) supported genetic separation among Alameda Creek trout and hatchery trout with greater than 50% bootstrap values in 1000 replicate neighbor-joining trees. Fish collected for this study from Palo Seco and Sheppard Creeks shared allelic frequencies with both the fish in Alameda Creek and those found in Scott Creek in Santa Cruz County. Fish collected in Horseshoe Creek or San Lorenzo Creek (Alameda County) did not share this unique genetic relationship between Alameda Creek fish and putative wild coastal trout. These two streams had allelic frequencies similar to some hatchery trout strains and to wild trout captured in the Central Valley. These data suggest that there are two possible steelhead ESUs using the tributaries of San Francisco Bay (one coastal and one Central Valley) or that hatchery trout supplementation has impacted some, but not all streams with a subsequent loss of locally adapted genetic characteristics. These data support the implementation of conservation management of rainbow trout in the Alameda Creek drainage as part of the central California coastal steelhead ESU.

  1. Structural architecture of the central Brooks Range foothills, Alaska

    Science.gov (United States)

    Moore, Thomas E.; Potter, Christopher J.; O'Sullivan, Paul B.

    2002-01-01

    Five structural levels underlie the Brooks Range foothills, from lowest to highest: (1) autochthon, at a depth of ~9 km; (2) Endicott Mountains allochthon (EMA), thickest under the northern Brooks Range (>15 km) and wedging out northward above the autochthon; (3) higher allochthons (HA), with a composite thickness of 1.5+ km, wedging out northward at or beyond the termination of EMA; (4) Aptian-Albian Fortress Mountain Formation (FM), deposited unconformably on deformed EMA and HA and thickening northward into a >7-km-thick succession of deformed turbidites (Torok Formation); (5) gently folded Albian-Cenomanian deltaic deposits (Nanushuk Group). The dominant faulting pattern in levels 2-3 is thin-skinned thrusting and thrust-related folds formed before deposition of Cretaceous strata. These structures are cut by younger steeply south-dipping reverse faults that truncate and juxtapose structural levels 1-4 and expose progressively deeper structural levels to the south. Structural levels 4-5 are juxtaposed along a north-dipping zone of south-vergent folds and thrusts. Stratigraphic and fission-track age data suggest a kinematic model wherein the foothills belt was formed first, by thrusting of HA and EMA as deformational wedges onto the regionally south-dipping authochon at 140-120Ma. After deposition of FM and Torok during mid-Cretaceous hinterland extension and uplift, a second episode of contractional deformation at 60 Ma shortened the older allochthonous deformational wedges (EMA, HA) and overlying strata on north-vergent reverse faults. To the north, where the allochthons wedge out, shortening caused duplexing in the Torok and development of a triangle zone south of the Tuktu escarpment.

  2. Evolution of adaptive diversity and genetic connectivity in Arctic charr (Salvelinus alpinus) in Iceland

    Science.gov (United States)

    Kapralova, K H; Morrissey, M B; Kristjánsson, B K; Ólafsdóttir, G Á; Snorrason, S S; Ferguson, M M

    2011-01-01

    The ecological theory of adaptive radiation predicts that the evolution of phenotypic diversity within species is generated by divergent natural selection arising from different environments and competition between species. Genetic connectivity among populations is likely also to have an important role in both the origin and maintenance of adaptive genetic diversity. Our goal was to evaluate the potential roles of genetic connectivity and natural selection in the maintenance of adaptive phenotypic differences among morphs of Arctic charr, Salvelinus alpinus, in Iceland. At a large spatial scale, we tested the predictive power of geographic structure and phenotypic variation for patterns of neutral genetic variation among populations throughout Iceland. At a smaller scale, we evaluated the genetic differentiation between two morphs in Lake Thingvallavatn relative to historically explicit, coalescent-based null models of the evolutionary history of these lineages. At the large spatial scale, populations are highly differentiated, but weakly structured, both geographically and with respect to patterns of phenotypic variation. At the intralacustrine scale, we observe modest genetic differentiation between two morphs, but this level of differentiation is nonetheless consistent with strong reproductive isolation throughout the Holocene. Rather than a result of the homogenizing effect of gene flow in a system at migration-drift equilibrium, the modest level of genetic differentiation could equally be a result of slow neutral divergence by drift in large populations. We conclude that contemporary and recent patterns of restricted gene flow have been highly conducive to the evolution and maintenance of adaptive genetic variation in Icelandic Arctic charr. PMID:21224880

  3. [Phylogeny of charrs of the genus Salvelinus based on mitochondrial DNA data].

    Science.gov (United States)

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

    2015-01-01

    Charrs of the genus Salvelinus (including Salvethymus) represent a monophyletic group of salmonid fishes that diverged from the common ancestor without subdivision into subgenera. The phylogenesis of the genus is characterized by four cycles of mitochondrial genome divergence. The first one, belonging to the Late Miocene--the border between Miocene and Pliocene (6 to 4 million years ago)--was associated with the consecutive divergence of the S. fontinalis, S. namaycush, S. levanidovi, and S. leucomaenis basal branches. Two divergence events, including separation of the ancestral lineage of western Pacific group of S. m. krascheninnikovi and the following segregation of the common ancestor into two mitochondrial phyla, happened within the period of 3 to 2 million years ago. The next cycle is attributed to the time interval of about 1 million years ago and includes the divergence of both phyla. In one phylum, a relatively quick isolation of Arctic and eastern Pacific phylogroups, along with the divergence of the latter phylogroup into S. confluentus and S. m. lordi lineages, took place. At the same time, the second phylum diverged into the S. m. malma and S. alpinus phylogenetic groups. At the final stage (Middle to Late Pleistocene), differentiation of the taxa within the phylogenetic groups took place.

  4. Residency and movement patterns of Arctic charr Salvelinus alpinus relative to major estuaries.

    Science.gov (United States)

    Spares, A D; Stokesbury, M J W; Dadswell, M J; O'Dor, R K; Dick, T A

    2015-06-01

    Estuarine residency and marine movements of 43 anadromous Arctic charr Salvelinus alpinus (mean ± s.d. fork length = 523 ± 97 mm) were examined using acoustic tracking in inner Frobisher Bay (IFB; 63° N; 68° W), Canada, from July to September 2008 and 2009. A mean ± s.d. migration duration of 63 ± 7 days occurred from late June to early September. Detected S. alpinus were either continuously (maximum 34 days) or intermittently present in estuarine zones, on average residing approximately one third of time tracked and returning once every 9 days. Significantly higher estuarine residency during the final 15 migration days suggested that a transition phase may occur prior to freshwater re-entry. Low travel rates during flood tide suggested individuals staged before accessing intertidal and estuarine zones. Although the two main estuaries were c. 22 km apart, 19% of tagged individuals used both. Individuals remained relatively close to freshwater overwintering systems, although late-migration inter-estuarine movements may have indicated natal homing. Approximately half of the individuals exhibited extra-estuarine travel, mostly during mid-migration, but remained within 3 km of shore ranging estuaries and (2) had a restricted marine distribution within 30 km SLD of the river mouths. © 2015 The Fisheries Society of the British Isles.

  5. Genome incompatibility between rainbow trout (Oncorhynchus mykiss) and sea trout (Salmo trutta) and induction of the interspecies gynogenesis.

    Science.gov (United States)

    Polonis, Marcin; Fujimoto, Takafumi; Dobosz, Stefan; Zalewski, Tomasz; Ocalewicz, Konrad

    2018-02-01

    Rainbow trout (Oncorhynchus mykiss Walbaum) and sea trout (Salmo trutta Linnaeus, 1758) show large karyotypic differences and their hybrid offspring is not viable due to unstable karyotype and chromosome fragmentation. However, gametes from these two species were used to induce gynogenetic development. Rainbow trout eggs activated by UV-irradiated sea trout sperm were subjected to high hydrostatic pressure (HHP) shock to prevent release of the 2nd polar body (early shock) or to inhibit the first cleavage (late shock) in order to produce diploid meiotic gynogenotes and gynogenetic doubled haploids (DHs), respectively. Cytogenetic analysis proved fish that development was induced by the sea trout spermatozoa were rainbow trout. In turn, molecular examination confirmed homozygosity of the gynogenetic DHs. Presumed appearance of the recessive alleles resulted in lower survival of the gynogenetic DH larvae (~25%) when compared to survival of the heterozygous (meiotic) gynogenotes (c. 50%). Our results proved that genomic incompatibilities between studied trout species result in the hybrid unviability. However, artificial gynogenesis including activation of rainbow trout eggs with UV-irradiated sea trout spermatozoa was successfully induced. As both species are unable to cross, application of the UV-irradiated sea trout spermatozoa to activate rainbow trout development assures only maternal inheritance with no contamination by the residues of the paternal chromosomes.

  6. Olemuse teater. Kantor ja Brook / Jan Kott ; tõlk. Eva-Liisa Linder

    Index Scriptorium Estoniae

    Kott, Jan

    2004-01-01

    T. Kantori lavastustest "Surnud klass" ja "Wielopole Wielopole" ning P. Brooki "Carmeni" lavastusest. Tõlgitud raamatust : Jan Kott. The Theatre of Essence: Kantor and Brook.- The Theatre of Essence and other Essays. Evanston, Northwestern University Press, 1984, lk. 159-165

  7. CRED 5 m Gridded bathymetry of Brooks Banks, Northwestern Hawaiian Islands, USA (NetCDF format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry (5m) of the shelf and slope environments of Brooks Banks, Hawaii, USA. The netCDF grid includes multibeam bathymetry from the Simrad EM300, Simrad...

  8. Making a Difference: The 1982 Humane Education Teacher of the Year-- Dr. Arlene Brooks.

    Science.gov (United States)

    Savesky, Kathy

    1982-01-01

    Profiles Dr. Arlene Brooks (1982 Humane Education Teacher of the Year) and four other teachers named as finalists. Discusses accomplishments, responsibilities, and humane education experiences/activities of these five individuals. (JN)

  9. CRED 5 m Gridded bathymetry of Brooks Banks, Hawaii, USA (Arc ASCII format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry (5m) of the shelf and slope environments of Brooks Banks, Hawaii, USA. The ASCII includes multibeam bathymetry from the Simrad EM300, Simrad...

  10. WATER QUALITY OF OLARIAS BROOKS AND THIS IMPACT IN THE PROJECTED DIKE.

    Directory of Open Access Journals (Sweden)

    Alysson Stefan Martins

    2010-11-01

    Full Text Available In Ponta Grossa city, in the attempt of revitalization of some spaces, start the construction of dikes in brooks, like what projected for the Olarias area. The aim oh this work, was to appraise and to monitor the quality oh water this brook, since the first mark the open sky until the local of possible dike, behind the determination the ions Cl-, PO43-, K+, NO3-, NH4+ and yet dissolved oxygen (DO, biochemical oxygen demand (BOD, consumed oxygen (CO, total and fecal coliforms. The analysis results, show that the brook contamination to domestic drain there is found mainly in the first levy mark; showing to be derived from downtown and that happen a gradual recovery of the brook, what indicate the addiction oh drain over it´s curse is less intense, but, his water arrives into the dike area, in similar conditions there is some that is founded in many lakes, whose water are eutrophizades.

  11. Microsatellite analyses of San Franciscuito Creek rainbow trout

    Science.gov (United States)

    Nielsen, Jennifer L.

    2000-01-01

    Microsatellite genetic diversity found in San Francisquito Creek rainbow trout support a close genetic relationship with rainbow trout (Oncorhynchus mykiss) from another tributary of San Francisco Bay, Alameda Creek, and coastal trout found in Lagunitas Creek, Marin County, California. Fish collected for this study from San Francisquito Creek showed a closer genetic relationship to fish from the north-central California steelhead ESU than for any other listed group of O. mykiss. No significant genotypic or allelic frequency associations could be drawn between San Francisquito Creek trout and fish collected from the four primary rainbow trout hatchery strains in use in California, i.e. Whitney, Mount Shasta, Coleman, and Hot Creek hatchery fish. Indeed, genetic distance analyses (δµ2) supported separation between San Francisquito Creek trout and all hatchery trout with 68% bootstrap values in 1000 replicate neighbor-joining trees. Not surprisingly, California hatchery rainbow trout showed their closest evolutionary relationships with contemporary stocks derived from the Sacramento River. Wild collections of rainbow trout from the Sacramento-San Joaquin basin in the Central Valley were also clearly separable from San Francisquito Creek fish supporting separate, independent ESUs for two groups of O. mykiss (one coastal and one Central Valley) with potentially overlapping life histories in San Francisco Bay. These data support the implementation of management and conservation programs for rainbow trout in the San Francisquito Creek drainage as part of the central California coastal steelhead ESU.

  12. Chapter 3. Rio Grande cutthroat trout

    Science.gov (United States)

    John N. Rinne

    1995-01-01

    The Rio Grande cutthroat trout was once widespread in the upper Rio Grande and Canadian River basins of northern New Mexico and south-central Colorado and in the headwaters of the Pecos River, New Mexico (Sublette et al. 1990; Behnke 1992). It may have occurred as far south as Chihuahua, Mexico (Behnke 1992). Currently, it is restricted primarily to headwater...

  13. Molecular characterization of rainbow trout, Oncorhynchus mykiss ...

    Indian Academy of Sciences (India)

    Microsatellite markers in combination with recent statistical approaches represent a useful tool for genetic characteriza- tion which ultimately supports the management of cultured stocks. These markers have been successfully used to eva- luate the wild and farm stocks of rainbow trout in western. Australia (Ward et al.

  14. Molecular characterization of rainbow trout, Oncorhynchus mykiss

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 94; Online resources. Molecular characterization of rainbow trout, Oncorhynchus mykiss (Walbaum, 1792) stocks in India. Ashoktaru Barat Prabhati K. Sahoo Rohit Kumar Javaid I. Mir Shahnawaz Ali Rabindar S. Patiyal Atul K. Singh. Volume 94 Online resources 2015 pp e13- ...

  15. Learning to Communicate Science: Stony Brook University's Approach

    Science.gov (United States)

    Bass, E.

    2012-12-01

    Stony Brook University offers an unusual series of short courses to help science graduate students learn to communicate more effectively about science with people outside their disciplines, including the public, public officials, potential funders and employers, students, the press, and colleagues in other fields. The courses include six 1-credit (14-hour) modules in oral and written communication that rely on practice and interactive feedback. More than 120 master's and PhD students, from more than 16 departments, have taken at least one of the courses since spring 2011. Most students who try one module end up taking two or three. An additional course for medical and nursing students was added in fall 2012. The courses are offered in the School of Journalism and were developed by the Center for Communicating Science (CCS). CCS was founded in 2009, with the participation of Alan Alda, the actor, writer, and longtime advocate for science, who is a Visiting Professor at Stony Brook. The Communicating Science courses have received strong institutional support and enthusiastic reviews. They are required by two programs, an MA in Marine Conservation and Policy and an Advanced Certificate in Health Communications. Two successive Provosts have subsidized course costs for PhD students, and Graduate School leaders are working to establish a steady funding stream to allow expansion of the program. Our aspiration at CCS is for every science graduate student to receive some training in communicating about science to the public. Several factors have helped in establishing the program: --CCS' multidisciplinary nature helped build support, with participation by faculty from across the campus, including not only the natural sciences, engineering, and medicine, but journalism, theatre arts, and the Writing Program, as well as nearby Brookhaven National Laboratory and Cold Spring Harbor Laboratory. --Before offering courses, CCS conducted all-day workshops and high

  16. Stocking impact and migration pattern in an anadromous brown trout ( Salmo trutta ) complex: where have all the stocked spawning sea trout gone?

    DEFF Research Database (Denmark)

    Ruzzante, D.E.; Hansen, Michael Møller; Meldrup, Dorte

    2004-01-01

    abandoned in the early 1990s, the proportion of sea trout of domestic origin was only 8.5%. Interestingly, for all three regional sea trout groups, virtually no sea trout of hatchery origin were found among the spawning individuals, which were on average larger than the nonspawning sea trout. These results...

  17. Determination of habitat requirements for Apache Trout

    Science.gov (United States)

    Petre, Sally J.; Bonar, Scott A.

    2017-01-01

    The Apache Trout Oncorhynchus apache, a salmonid endemic to east-central Arizona, is currently listed as threatened under the U.S. Endangered Species Act. Establishing and maintaining recovery streams for Apache Trout and other endemic species requires determination of their specific habitat requirements. We built upon previous studies of Apache Trout habitat by defining both stream-specific and generalized optimal and suitable ranges of habitat criteria in three streams located in the White Mountains of Arizona. Habitat criteria were measured at the time thought to be most limiting to juvenile and adult life stages, the summer base flow period. Based on the combined results from three streams, we found that Apache Trout use relatively deep (optimal range = 0.15–0.32 m; suitable range = 0.032–0.470 m) pools with slow stream velocities (suitable range = 0.00–0.22 m/s), gravel or smaller substrate (suitable range = 0.13–2.0 [Wentworth scale]), overhead cover (suitable range = 26–88%), and instream cover (large woody debris and undercut banks were occupied at higher rates than other instream cover types). Fish were captured at cool to moderate temperatures (suitable range = 10.4–21.1°C) in streams with relatively low maximum seasonal temperatures (optimal range = 20.1–22.9°C; suitable range = 17.1–25.9°C). Multiple logistic regression generally confirmed the importance of these variables for predicting the presence of Apache Trout. All measured variables except mean velocity were significant predictors in our model. Understanding habitat needs is necessary in managing for persistence, recolonization, and recruitment of Apache Trout. Management strategies such as fencing areas to restrict ungulate use and grazing and planting native riparian vegetation might favor Apache Trout persistence and recolonization by providing overhead cover and large woody debris to form pools and instream cover, shading streams and lowering temperatures.

  18. Simulating the effect of climate change on stream temperature in the Trout Lake Watershed, Wisconsin

    Energy Technology Data Exchange (ETDEWEB)

    Selbig, William R., E-mail: wrselbig@usgs.gov

    2015-07-15

    The potential for increases in stream temperature across many spatial and temporal scales as a result of climate change can pose a difficult challenge for environmental managers, especially when addressing thermal requirements for sensitive aquatic species. This study evaluates simulated changes to the thermal regime of three northern Wisconsin streams in response to a projected changing climate using a modeling framework and considers implications of thermal stresses to the fish community. The Stream Network Temperature Model (SNTEMP) was used in combination with a coupled groundwater and surface water flow model to assess forecasts in climate from six global circulation models and three emission scenarios. Model results suggest that annual average stream temperature will steadily increase approximately 1.1 to 3.2 °C (varying by stream) by the year 2100 with differences in magnitude between emission scenarios. Daily mean stream temperature during the months of July and August, a period when cold-water fish communities are most sensitive, showed excursions from optimal temperatures with increased frequency compared to current conditions. Projections of daily mean stream temperature, in some cases, were no longer in the range necessary to sustain a cold water fishery. - Highlights: • A stream temperature model was calibrated for three streams in northern Wisconsin. • The effect of climate change on stream temperature was simulated in each stream. • Annual average stream temperature was projected to rise from 1 to 3 °C by 2100. • Forecasts of stream temperature exceeded optimal ranges for brook trout.

  19. Submarine Groundwater Discharge in Stony Brook Harbor, NY

    Science.gov (United States)

    Durand, J. M.; Young, C.; Wong, T.; Hanson, G. N.

    2012-12-01

    As nutrients can significantly impact coastal ecosystems, understanding their path to embayments and oceans is crucial. In Stony Brook Harbor (Long Island, NY), submarine groundwater discharge (SGD) is the only significant contribution of freshwater and thus constitutes the main pathway for nutrients, which may eventually reach Long Island Sound. Subterranean estuaries have been shown to be highly reactive zones where nitrogen attenuation can occur. Understanding the fate of nitrogen in Stony Brook Harbor requires knowing the volume of groundwater entering the bay as well as the amount of denitrification, in the context of the hydrogeological framework. This is achieved by combining electrical resistivity survey, water sampling in piezometers, point conductivity and seepage measurements. A Trident probe inserted 60 cm deep into the sediments allows measuring the conductivity and temperature of the sediments and the overlying seawater. In spring 2011, five Trident transects spreading across the head of the harbor were used as a preliminary study to reveal potential locations for SGD. Locations with significant difference between sediment and seawater temperature and/or conductivities were further investigated using an AGI SuperSting 8-channel receiver resistivity meter. Two ultrasonic seepage meters were deployed in May and July 2011 about 20 m below the low tide mark. Five piezometers were aligned parallel to one resistivity survey. Our resistivity data indicate superficial mixing in the intertidal zone. The freshwater extends quite far under the seafloor, above 67 meters after the low tide mark for one location. The freshwater/saltwater interface seems to be almost horizontal. The piezometer data agree relatively well with the resistivity data. The preliminary average seepage rates observed vary from 3 to 60 cm/d. The resistivity sections reveal the presence of a thin layer of high conductivity above the low tide mark. This matches the observation of a superficial

  20. Impact of forest harvesting on trophic structure of eastern Canadian Boreal Shield lakes: insights from stable isotope analyses.

    Science.gov (United States)

    Glaz, Patricia; Sirois, Pascal; Archambault, Philippe; Nozais, Christian

    2014-01-01

    Perturbations on ecosystems can have profound immediate effects and can, accordingly, greatly alter the natural community. Land-use such as forestry activities in the Canadian Boreal region have increased in the last decades, raising concerns about their potential impact on aquatic ecosystems. The objective of this study was to evaluate the impact of forest harvesting on trophic structure in eastern Canadian Boreal Shield lakes. We measured carbon and nitrogen stable isotopes values for aquatic primary producers, terrestrial detritus, benthic macroinvertebrates, zooplankton and brook trout (Salvelinus fontinalis) over a three-year period in eight eastern Boreal Shield lakes. Four lakes were studied before, one and two years after forest harvesting (perturbed lakes) and compared with four undisturbed reference lakes (unperturbed lakes) sampled at the same time. Stable isotope mixing models showed leaf-litter to be the main food source for benthic primary consumers in both perturbed and unperturbed lakes, suggesting no logging impact on allochthonous subsidies to the littoral food web. Brook trout derived their food mainly from benthic predatory macroinvertebrates in unperturbed lakes. However, in perturbed lakes one year after harvesting, zooplankton appeared to be the main contributor to brook trout diet. This change in brook trout diet was mitigated two years after harvesting. Size-related diet shift were also observed for brook trout, indicating a diet shift related to size. Our study suggests that carbon from terrestrial habitat may be a significant contribution to the food web of oligotrophic Canadian Boreal Shield lakes. Forest harvesting did not have an impact on the diet of benthic primary consumers. On the other hand, brook trout diet composition was affected by logging with greater zooplankton contribution in perturbed lakes, possibly induced by darker-colored environment in these lakes one year after logging.

  1. THEOLOGY AS CREATIVE LANGUAGE. THE CASE OF THOMAS BROOKS

    Directory of Open Access Journals (Sweden)

    Ciprian SIMUȚ

    2015-12-01

    Full Text Available The problem of theological language has been a hindrance in coming closer to God, ever since complex patterns of thought have combined with the theological inquiry. The conclusion that helped Protestantism gain ground was bringing the theological message of the Bible to the understanding of every-day believer. An effort was made to explain how God works in history, and how to become more like Christ in one’s every-day life. However, mere copying was not the foundation of Christianity. Inner conviction born out of understanding the explanation from the Biblical message was crucial. Thomas Brooks was one of the protestant theologians who aimed to explain how the Devil and evil work against the believer, in order to create chaos, disorder, sorrow, hatred, deception, and ignorance. He did this by transforming the theological message into creative language, using every-day images in order to create a relation between theology and praxis. This paper will analyze some of the aspects found in Brooks’ theological presentation, in order to show how theology could be used for the benefit of the individual believer, as well as for the benefit of society.

  2. Patterns of streamwater acidity in Lye Brook Wilderness, Vermont, USA.

    Science.gov (United States)

    Campbell, John L; Eagar, Christopher; McDowell, William H

    2002-08-01

    Under the United States Clean Air Act Amendments of 1977, a class I designation safeguards wilderness areas from the negative effects of new sources of air pollution. We monitored streamwater chemistry in the class I Lye Brook Wilderness in southwestern Vermont from May 1994 through August 1995. Stream samples were collected biweekly at nine sampling locations throughout the wilderness and were analyzed for major cations and anions, dissolved organic carbon, pH, and acid-neutralizing capacity. Eight of nine sites sampled had mean annual acid neutralizing capacity values below zero. During the study period, decreases in streamwater acid neutralizing capacity values were caused primarily by SO(4)(2-). At some sites, however, NO(3) (-) and naturally occurring, weak organic acids were seasonally important. During high discharge, the low pH and high concentrations of inorganic monomeric Al were at levels that are toxic to acid-sensitive aquatic species. Watershed mass balances were calculated to determine annual gains or losses for measured ions. These budgets indicate that S inputs and outputs were nearly equal, there was a net loss of base cations, and a net gain in N. How long these watersheds can continue to assimilate additional N inputs is unknown.

  3. Sensitivity of Trout to Chronic Acute Exposure to Selenium

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Gissel; Nielsen, M. Gissel

    1978-01-01

    Trout were exposed to selenite (Na2SeO3) solutions of varying concentrations (0.1-100 ppm Se) for periods of up to 4 wk. A chronic exposure to 0.1 ppm Se or less is non-lethal to trout. Lethality at higher concentrations depends on the length of exposure. Trout that survive for 10 days in tap-wat...

  4. Correlation between Leukocyte Numbers and Body Size of Rainbow Trout

    DEFF Research Database (Denmark)

    Mohammad, Rezkar Jaafar; Otani, Maki; Kania, Per Walter

    2016-01-01

    Immune cells in rainbow trout Oncorhynchus mykiss comprise granulocytes (neutrophils, basophils and eosinophils), macrophages/monocytes and lymphocytes (B- and T-cells). These cellular elements occur early during the ontogenetic development of trout and allow both innate and adaptive responses...... wild and cultured fish and we show that the size of the leukocyte population increases exponentially with body size of rainbow trout. Four groups (5 fish/group) of naive rainbow trout (Oncorhynchus mykiss) with a mean body weight of 2 - 4 g (group I), 4 - 6 g (group II), 25 - 30 g (group III), and 650...

  5. Production of trout offspring from triploid salmon parents.

    Science.gov (United States)

    Okutsu, Tomoyuki; Shikina, Shinya; Kanno, Megumi; Takeuchi, Yutaka; Yoshizaki, Goro

    2007-09-14

    Many salmonids have become at risk of extinction. For teleosts whose eggs cannot be cryopreserved, developing techniques other than egg cryopreservation to save genetic resources is imperative. In this study, spermatogonia from rainbow trout were intraperitoneally transplanted into newly hatched sterile triploid masu salmon. Transplanted trout spermatogonia underwent spermatogenesis and oogenesis in male and female recipients, respectively. At 2 years after transplantation, triploid salmon recipients only produced trout sperm and eggs. With use of these salmon as parents, we successfully produced only donor-derived trout offspring. Thus, by transplanting cryopreserved spermatogonia into sterile xenogeneic recipients, we can generate individuals of a threatened species.

  6. 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.

  7. A trial of two trouts: Comparing the impacts of rainbow and brown trout on a native galaxiid

    Science.gov (United States)

    Young, K.A.; Dunham, J.B.; Stephenson, J.F.; Terreau, A.; Thailly, A.F.; Gajardo, G.; de Leaniz, C. G.

    2010-01-01

    Rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta are the world's two most widespread exotic fishes, dominate the fish communities of most cold-temperate waters in the southern hemisphere and are implicated in the decline and extirpation of native fish species. Here, we provide the first direct comparison of the impacts of rainbow and brown trout on populations of a native fish by quantifying three components of exotic species impact: range, abundance and effect. We surveyed 54 small streams on the island of Chilo?? in Chilean Patagonia and found that the rainbow trout has colonized significantly more streams and has a wider geographic range than brown trout. The two species had similar post-yearling abundances in allopatry and sympatry, and their abundances depended similarly on reach-level variation in the physical habitat. The species appeared to have dramatically different effects on native drift-feeding Aplochiton spp., which were virtually absent from streams invaded by brown trout but shared a broad sympatric range with rainbow trout. Within this range, the species' post-yearling abundances varied independently before and after controlling for variation in the physical habitat. In the north of the island, Aplochiton spp. inhabited streams uninvaded by exotic trouts. Our results provide a context for investigating the mechanisms responsible for apparent differences in rainbow and brown trout invasion biology and can help inform conservation strategies for native fishes in Chilo?? and elsewhere. ?? 2010 The Authors. Journal compilation ?? 2010 The Zoological Society of London.

  8. HPLC and ELISA analyses of larval bile acids from Pacific and western brook lampreys.

    Science.gov (United States)

    Yun, Sang-Seon; Scott, Alexander P; Bayer, Jennifer M; Seelye, James G; Close, David A; Li, Weiming

    2003-08-01

    Comparative studies were performed on two native lamprey species, Pacific lamprey (Lampetra tridentata) and western brook lamprey (Lampetra richardsoni) from the Pacific coast along with sea lamprey (Petromyzon marinus) from the Great Lakes, to investigate their bile acid production and release. HPLC and ELISA analyses of the gall bladders and liver extract revealed that the major bile acid compound from Pacific and western brook larval lampreys was petromyzonol sulfate (PZS), previously identified as a migratory pheromone in larval sea lamprey. An ELISA for PZS has been developed in a working range of 20 pg-10 ng per well. The tissue concentrations of PZS in gall bladder were 127.40, 145.86, and 276.96 micro g/g body mass in sea lamprey, Pacific lamprey, and western brook lamprey, respectively. Releasing rates for PZS in the three species were measured using ELISA to find that western brook and sea lamprey released PZS 20 times higher than Pacific lamprey did. Further studies are required to determine whether PZS is a chemical cue in Pacific and western brook lampreys.

  9. HPLC and ELISA analyses of larval bile acids from Pacific and western brook lampreys

    Science.gov (United States)

    Yun, S.-S.; Scott, A.P.; Bayer, J.M.; Seelye, J.G.; Close, D.A.; Li, W.

    2003-01-01

    Comparative studies were performed on two native lamprey species, Pacific lamprey (Lampetra tridentata) and western brook lamprey (Lampetra richardsoni) from the Pacific coast along with sea lamprey (Petromyzon marinus) from the Great Lakes, to investigate their bile acid production and release. HPLC and ELISA analyses of the gall bladders and liver extract revealed that the major bile acid compound from Pacific and western brook larval lampreys was petromyzonol sulfate (PZS), previously identified as a migratory pheromone in larval sea lamprey. An ELISA for PZS has been developed in a working range of 20pg-10ng per well. The tissue concentrations of PZS in gall bladder were 127.40, 145.86, and 276.96??g/g body mass in sea lamprey, Pacific lamprey, and western brook lamprey, respectively. Releasing rates for PZS in the three species were measured using ELISA to find that western brook and sea lamprey released PZS 20 times higher than Pacific lamprey did. Further studies are required to determine whether PZS is a chemical cue in Pacific and western brook lampreys. ?? 2003 Elsevier Inc. All rights reserved.

  10. Science in Flux: NASA's Nuclear Program at Plum Brook Station 1955-2005

    Science.gov (United States)

    Bowles, Mark D.

    2006-01-01

    Science in Flux traces the history of one of the most powerful nuclear test reactors in the United States and the only nuclear facility ever built by NASA. In the late 1950's NASA constructed Plum Brook Station on a vast tract of undeveloped land near Sandusky, Ohio. Once fully operational in 1963, it supported basic research for NASA's nuclear rocket program (NERVA). Plum Brook represents a significant, if largely forgotten, story of nuclear research, political change, and the professional culture of the scientists and engineers who devoted their lives to construct and operate the facility. In 1973, after only a decade of research, the government shut Plum Brook down before many of its experiments could be completed. Even the valiant attempt to redefine the reactor as an environmental analysis tool failed, and the facility went silent. The reactors lay in costly, but quiet standby for nearly a quarter-century before the Nuclear Regulatory Commission decided to decommission the reactors and clean up the site. The history of Plum Brook reveals the perils and potentials of that nuclear technology. As NASA, Congress, and space enthusiasts all begin looking once again at the nuclear option for sending humans to Mars, the echoes of Plum Brook's past will resonate with current policy and space initiatives.

  11. 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. © 2014 The Fisheries Society of the British Isles.

  12. LopheliaII2012: Coral Research on Oil Rigs in the Gulf of Mexico on TDI-Brooks Vessel Brooks McCall between 2012-07-12 and 2012-07-24

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The final year of a multi-year effort to study Lophelia coral communities in the Gulf of Mexico is occurring on the TDI-Brooks research vessel, Brooks McCall,...

  13. Field report: Exploring the Doonerak fenster of the central Brooks Range, Alaska, USA

    Directory of Open Access Journals (Sweden)

    Justin V. Strauss

    2017-07-01

    Full Text Available Arctic Alaska is a ‘suspect’ terrane that encompasses approximately 20% of Alaska, stretching from the southern Brooks Range all the way to the continental shelves of the Chukchi and Beaufort Seas. Although the origin and subsequent travels of this large crustal fragment are debated among geologists, most researchers agree upon its composite nature and exotic origin. To constrain the early geological history of this terrane, we describe a recent expedition to the Doonerak fenster of the central Brooks Range. This area has long been regarded as a key locality for understanding the structural evolution of the Mesozoic–Cenozoic Brooks Range orogen; however, our target was different: a unique sequence of volcanic and siliciclastic rocks (Apoon assemblage exposed beneath a profound pre-Mississippian unconformity, which we argue is of key importance to understanding the early Paleozoic tectonic history of northern Alaska and the greater Arctic.

  14. 75 FR 52374 - National Environmental Policy Act; NASA Glenn Research Center Plum Brook Station Wind Farm Project

    Science.gov (United States)

    2010-08-25

    ... Environmental Policy Act; NASA Glenn Research Center Plum Brook Station Wind Farm Project AGENCY: National... scoping and prepare an Environmental Impact Statement (EIS) for the NASA GRC Plum Brook Station Wind Farm... scoping is for NASA to obtain public comments on construction and operation of the wind farm. The purpose...

  15. Chemistry of precipitation, streamwater, and lakewater from the Hubbard Brook Ecosystem Study: a record of sampling protocols and analytical procedures

    Science.gov (United States)

    Donald C. Buso; Gene E. Likens; John S. Eaton

    2000-01-01

    The Hubbard Brook Ecosystem Study (HBES), begun in 1963, is a long-term effort to understand the structure, function and change in forest watersheds and associated aquatic ecosystems at the Hubbard Brook Experimental Forest in New Hampshire. Chemical analyses of streamwater and precipitation collections began in 1963, and analyses of lakewater collections began in 1967...

  16. Ecological segregation moderates a climactic conclusion to trout hybridization

    Science.gov (United States)

    Michael K. Young; Daniel J. Isaak; Kevin S. McKelvey; Taylor M. Wilcox; Matthew R. Campbell; Matthew P. Corsi; Dona Horan; Michael K. Schwartz

    2017-01-01

    Invasive hybridization, in which an introduced species may introgressively hybridize with a native taxon and threaten its persistence, is prominently featured in the conservation literature. One of the most frequently cited examples of this phenomenon involves interactions between native westslope cutthroat trout Oncorhynchus clarkii lewisi and introduced rainbow trout...

  17. Communications: Blood chemistry of laboratory-reared Golden trout

    Science.gov (United States)

    Hunn, Joseph B.; Wiedmeyer, Ray H.; Greer, Ivan E.; Grady, Andrew W.

    1992-01-01

    Golden trout Oncorhynchus aguabonita obtained from a wild stock as fertilized eggs were reared in the laboratory for 21 months. The laboratory-reared golden trout in our study reached sexual maturity earlier and grew more rapidly than wild golden trout do (according to the scientific literature). Male fish averaged 35.6 cm in total length and 426 g in weight, and females averaged 36.2 cm and 487 g. All golden trout were sexually mature when used for hematological analysis. The hematological profile (hematocrit, red blood cells, white blood cells, and thrombocytes) of golden trout was similar to that reported elsewhere for other trout species. Male and female golden trout did not have significantly different thrombocyte counts; however, the immobilization treatment used on the fish (anesthesia versus a blow to the head) resulted in significant treatment differences in thrombocyte numbers and interaction effect of sex in treatment for hematocrits. Gravid female golden trout had significantly higher plasma protein and calcium levels than did males. The ionic compositions of plasma (sodium, potassium, calcium, magnesium, copper, zinc, iron, and chloride) and gallbladder bile (calcium and chloride) were similar to those reported for other salmonids.

  18. SuchThatCast Episode 3: J.D. Trout

    NARCIS (Netherlands)

    Soraker, Johnny

    2012-01-01

    SuchThatCast goes mobile in the third episode, as I interview J.D. Trout on the appr. 2 hour train ride between Enschede and Schiphol airport. Trout received his PhD in Philosophy at Cornell University and is currently Professor of Philosophy and Psychology at Loyola University Chicago. He was

  19. Secondary immune response of rainbow trout following repeated immersion vaccination

    DEFF Research Database (Denmark)

    Jaafar, R. M.; Al-Jubury, Azmi; Chettri, Jiwan Kumar

    2018-01-01

    vaccination of fish raises a secondary immune response, consisting of rapid, accelerated and increased antibody reaction. This study reports how rainbow trout responds to repeated immersion vaccination against yersiniosis (ERM) caused by the bacterial pathogen Yersinia ruckeri. It was found that rainbow trout...

  20. Secondary immune response of rainbow trout following repeated immersion vaccination

    DEFF Research Database (Denmark)

    Jaafar, R. M.; Al-Jubury, A.; Chettri, J. K.

    2017-01-01

    vaccination of fish raises a secondary immune response, consisting of rapid, accelerated and increased antibody reaction. This study reports how rainbow trout responds to repeated immersion vaccination against yersiniosis (ERM) caused by the bacterial pathogen Yersinia ruckeri. It was found that rainbow trout...

  1. Influence of waterfalls on patterns of association between trout and ...

    African Journals Online (AJOL)

    Relative abundances of trout and tadpoles of Natal cascade frogs were assessed after sampling using electrofishing. Habitat templates were compared for above- versus below-waterfall sites. Trout predation is the most likely causative agent for an observed abrupt decline in H. natalensis tadpole abundance occurring ...

  2. A watershed-scale monitoring protocol for bull trout

    Science.gov (United States)

    Dan Isaak; Bruce Rieman; Dona Horan

    2009-01-01

    Bull trout is a threatened species native to the Pacific Northwest that has been selected as Management Indicator Species on several national forests. Scientifically defensible procedures for monitoring bull trout populations are necessary that can be applied to the extensive and remote lands managed by the U.S. Forest Service. Distributional monitoring focuses...

  3. Otter ( Lutra lutra ) predation on stocked brown trout ( Salmo trutta ) in two Danish lowland rivers

    DEFF Research Database (Denmark)

    Jacobsen, Lene

    2005-01-01

    This study aimed to evaluate otter predation on stocked trout. Large hatchery-reared trout (16-30 cm) were stocked into two Danish rivers with different fish populations. Otter diet before and after trout stocking was determined by analysing 685 spraints, collected regularly during the 35-day study...... the lengths of stocked trout, indicating that newly stocked trout were preferred to wild trout. In River Skals, dominated by cyprinids, there was no change in otter diet after stocking of hatchery trout, i.e., these were ignored by otter. Otter predation should be taken into account together with fish...

  4. William Keith Brooks and the naturalist's defense of Darwinism in the late-nineteenth century.

    Science.gov (United States)

    Nash, Richard

    2015-06-01

    William Keith Brooks was an American zoologist at Johns Hopkins University from 1876 until his death in 1908. Over the course of his career, Brooks staunchly defended Darwinism, arguing for the centrality of natural selection in evolutionary theory at a time when alternative theories, such as neo-Lamarckism, grew prominent in American biology. In his book The Law of Heredity (1883), Brooks addressed problems raised by Darwin's theory of pangenesis. In modifying and developing Darwin's pangenesis, Brooks proposed a new theory of heredity that sought to avoid the pitfalls of Darwin's hypothesis. In so doing he strengthened Darwin's theory of natural selection by undermining arguments for the inheritance of acquired characteristics. In later attacks on neo-Lamarckism, Brooks consistently defended Darwin's theory of natural selection on logical grounds, continued to challenge the idea of the inheritance of acquired characteristics, and argued that natural selection best explained a wide range of adaptations. Finally, he critiqued Galton's statistical view of heredity and argued that Galton had resurrected an outmoded typological concept of species, one which Darwin and other naturalists had shown to be incorrect. Brooks's ideas resemble the "biological species concept" of the twentieth century, as developed by evolutionary biologist Ernst Mayr and others. The late-nineteenth century was not a period of total "eclipse" of Darwinism, as biologists and historians have hitherto seen it. Although the "Modern Synthesis" refers to the reconciliation of post-Mendelian genetics with evolution by natural selection, we might adjust our understanding of how the synthesis developed by seeing it as the culmination of a longer discussion that extends back to the late-nineteenth century.

  5. 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.

  6. Do low-mercury terrestrial resources subsidize low-mercury growth of stream fish? Differences between species along a productivity gradient.

    Science.gov (United States)

    Ward, Darren M; Nislow, Keith H; Folt, Carol L

    2012-01-01

    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.

  7. Streptococcus iniae expresses a cell surface non-immune trout immunoglobulin-binding factor when grown in normal trout serum.

    Science.gov (United States)

    Barnes, Andrew C; Horne, Michael T; Ellis, Anthony E

    2003-11-01

    Three capsulated isolates of S. iniae representing serotype I and II and being arginine dihydrolase positive, negative or variable (AD+ve, AD-ve, AD+-ve) were investigated for their ability to bind rainbow trout serum immunoglobulin by the Fc region. Using a coagglutination assay with bacteria grown in Todd-Hewitt broth (THB), no evidence of non-specific Fc-binding of trout immunoglobulin (Ig) was obtained. However, when grown in normal trout serum, all isolates produced similar protein patterns in SDS-PAGE, but they were markedly different from the patterns of the bacteria grown in THB. Some bands with MW 70 kDa and over 100 kDa were very intense in the profiles of the serum-grown isolates. In Western blots, these bands of all isolates were immunostained with the conjugated goat antiserum to trout Ig, after blocking with normal goat serum, demonstrating that the bacteria had bound the trout Ig during growth in the serum. When the isolates were grown overnight in trout antiserum against Lactococcus garvieae they coagglutinated with L. garvieae cells but S. iniae isolates grown in normal trout serum did not. These data indicate that S. iniae grown in serum express surface factors which can bind trout Ig by the Fc-region.

  8. Effects of water temperature and fish size on predation vulnerability of juvenile humpback chub to rainbow trout and brown trout

    Science.gov (United States)

    Ward, David L.; Morton-Starner, Rylan

    2015-01-01

    Predation on juvenile native fish by introduced Rainbow Trout and Brown Trout is considered a significant threat to the persistence of endangered Humpback Chub Gila cypha in the Colorado River in the Grand Canyon. Diet studies of Rainbow Trout and Brown Trout in Glen and Grand canyons indicate that these species do eat native fish, but impacts are difficult to assess because predation vulnerability is highly variable, depending on prey size, predator size, and the water temperatures under which the predation interactions take place. We conducted laboratory experiments to evaluate how short-term predation vulnerability of juvenile native fish changes in response to fish size and water temperature using captivity-reared Humpback Chub, Bonytail, and Roundtail Chub. Juvenile chub 45–90 mm total length (TL) were exposed to adult Rainbow and Brown trouts at 10, 15, and 20°C to measure predation vulnerability as a function of water temperature and fish size. A 1°C increase in water temperature decreased short-term predation vulnerability of Humpback Chub to Rainbow Trout by about 5%, although the relationship is not linear. Brown Trout were highly piscivorous in the laboratory at any size > 220 mm TL and at all water temperatures we tested. Understanding the effects of predation by trout on endangered Humpback Chub is critical in evaluating management options aimed at preserving native fishes in Grand Canyon National Park.

  9. The effect of Cu2+ on osmoregulation in rainbow trout (Oncorhynchus mykiss) assayed by changes in plasma salinity and gill lipid metabolism

    DEFF Research Database (Denmark)

    Hansen, Heinz J.M.; Olsen, Allan Gylling; Rosenkilde, Per

    1993-01-01

    Zoofysiologi, Osmoregulation, Lipid metabolism, Ecotoxicology, Rainbow trout, Oncorhynchus mykiss.......Zoofysiologi, Osmoregulation, Lipid metabolism, Ecotoxicology, Rainbow trout, Oncorhynchus mykiss....

  10. Analysis of nitrogen dynamics in the Lye Brook Wilderness Area, Vermont, USA

    Science.gov (United States)

    John L. Campbell; Christopher Eagar; William H. McDowell; James W. Hornbeck

    2000-01-01

    Nitrogen (N) deposition and its impact on terrestrial and aquatic ecosystems is a concern facing federal land managers at the Lye Brook Wilderness in Vermont and other protected areas throughout the northeastern United States. In this study, we compared N production in soils with N concentrations and outputs in leachates to determine how forest cover types differ in...

  11. On the identity of Cervus nigricans Brooke, 1877, with remarks upon other deer from the Philippines

    NARCIS (Netherlands)

    Dobroruka, L.J.

    1971-01-01

    A great number of papers deal with the deer of the Philippine Islands but in spite of this fact the taxonomy and the nomenclature are still not clear. The first author who recapitulated all known facts about the Philippine deer was Brooke (1877), who also described a new species, Cervus nigricans.

  12. Effects of temperature on survival and development of early life stage Pacific and western brook lampreys

    Science.gov (United States)

    Meeuwig, M.H.; Bayer, J.M.; Seelye, J.G.

    2005-01-01

    We examined the effects of temperature (10, 14, 18, and 22??C) on survival and development of Pacific lampreys Lampetra tridentata and western brook lampreys L. richardsoni during embryological and early larval stages. The temperature for zero development was estimated for each species, and the response to temperature was measured as the proportion of individuals surviving to hatch, surviving to the larval stage, and exhibiting abnormalities at the larval stage (i.e., malformations of the body). The estimated temperature for zero development was 4.850C for Pacific lampreys and 4.97??C for western brook lampreys. Survival was greatest at 18??C, followed by 14, 10, and 22??C, significant differences being observed between 22??C and the other temperatures. Overall survival was significantly greater for western brook lampreys than for Pacific lampreys; however, the overall difference in proportion of individuals surviving was only 0.02. Overall survival significantly decreased from the time of hatch (proportion surviving = 0.85) to the larval stage (0.82; i.e., during the free-embryo stage). The proportion of individuals exhibiting abnormalities at the larval stage was greatest at 22??C, followed by 18, 10, and 14??C, significant differences being observed between 22??C and the other temperatures. These data provide baseline information on the thermal requirements of early life stage Pacific and western brook lampreys and will aid in assessment and prediction of suitable spawning and rearing habitats for these species.

  13. Elevation dependent sensitivity of northern hardwoods to Ca addition at Hubbard Brook Experimental Forest, NH USA

    Science.gov (United States)

    Rakesh Minocha; Stephanie Long; Palaniswamy Thangavel; Subhash C. Minocha; Christopher Eagar; Charles T. Driscoll

    2010-01-01

    Acidic deposition has caused a depletion of calcium (Ca) in the northeastern forest soils. Wollastonite (Ca silicate) was added to watershed 1 (WS1) at the Hubbard Brook Experimental Forest (HBEF) in 1999 to evaluate its effects on various functions of the HBEF ecosystem. The effects of Ca addition on foliar soluble (extractable in 5% HClO4) ions...

  14. Long-term trends from ecosystem research at the Hubbard Brook Experimental Forest

    Science.gov (United States)

    John L. Campbell; Charles T. Driscoll; Christopher Eagar; Gene E. Likens; Thomas G. Siccama; Chris E. Johnson; Timothy J. Fahey; Steven P. Hamburg; Richard T. Holmes; Amey S. Bailey; Donald C. Buso

    2007-01-01

    Summarizes 52 years of collaborative, long-term research conducted at the Hubbard Brook (NH) Experimental Forest on ecosystem response to disturbances such as air pollution, climate change, forest disturbance, and forest management practices. Also provides explanations of some of the trends and lists references from scientific literature for further reading.

  15. Modeling ecohydrologic processes at Hubbard Brook: Initial results for Watershed 6 stream discharge and chemistry

    Science.gov (United States)

    The Hubbard Brook Long Term Ecological Research site has produced some of the most extensive and long-running databases on the hydrology, biology and chemistry of forest ecosystem responses to climate and forest harvest. We used these long-term databases to calibrate and apply G...

  16. A useful single-solution polychrome stain for plant material...Brook Cyte-Chrome I.

    Science.gov (United States)

    Stanley L Krugman; Julia F. Littlefield

    1968-01-01

    Fresh and chemically fixed sectioned plant material can be quickly stained by applying a Brook Cyte Chrome I polychrome stain. Staining time averaged only about 10 minutes. And exact timing of staining and de-staining is not as critical as with most of the commonly used stains. The overall quality is comparable to that of the traditional stains.

  17. 77 FR 63897 - Notice of License Terminations for National Aeronautics and Space Administration; Plum Brook...

    Science.gov (United States)

    2012-10-17

    ... confirmatory surveys, the NRC has concluded that the decommissioning process is complete and the facility and... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY... Reactor and Plum Brook Mock-Up Reactor The U.S. Nuclear Regulatory Commission (NRC or the Commission) is...

  18. Chip Frazier named Thomas M. Brooks Professor of Wood Science and Forest Products

    OpenAIRE

    Davis, Lynn

    2007-01-01

    Charles E. "Chip" Frazier of Blacksburg, professor of wood science and forest products in the College of Natural Resources at Virginia Tech, has been appointed the Thomas M. Brooks Professor of Wood Science and Forest Products by the Virginia Tech Board of Visitors during the board's quarterly meeting March 26.

  19. EXPERIMENTAL ACIDIFICATION CAUSES SOIL BASE-CATION DEPLETION AT THE BEAR BROOK WATERSHED IN MAINE

    Science.gov (United States)

    There is concern that changes in atmospheric deposition, climate, or land use have altered the biogeochemistry of forests causing soil base-cation depletion, particularly Ca. The Bear Brook Watershed in Maine (BBWM) is a paired watershed experiment with one watershed subjected to...

  20. IMPACTS OF MARINE AEROSOLS ON SURFACE WATER CHEMISTRY AT BEAR BROOK WATERSHED, MAINE USA

    Science.gov (United States)

    The East Bear catchment at Bear Brook Watershed, Maine receives moderate (for the eastern U.S.) amounts of Cl- in wet and dry deposition. In 1989, Cl- in precipitation ranged from 2 to 55 eq/L. Dry, occult, and wet deposition plus evapotranspiration resulted in stream Cl- averagi...

  1. SOIL ALUMINUM DISTRIBUTION IN THE NEAR-STREAM ZONE AT THE BEAR BROOK WATERSHED IN MAINE

    Science.gov (United States)

    Near-stream and upslope soil chemical properties were analyzed to infer linkages between soil and surface water chemistry at the Bear Brook Watershed in Maine [BBWM]. Organic and mineral soil samples were collected along six 20 m transects perpendicular to the stream and one 200 ...

  2. Linking water age and solute dynamics in streamflow at the Hubbard Brook Experimental Forest, NH, USA

    Science.gov (United States)

    Paolo Benettin; Scott W. Bailey; John L. Campbell; Mark B. Green; Andrea Rinaldo; Gene E. Likens; Kevin J. McGuire; Gianluca Botter

    2015-01-01

    We combine experimental and modeling results from a headwater catchment at the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA, to explore the link between stream solute dynamics and water age. A theoretical framework based on water age dynamics, which represents a general basis for characterizing solute transport at the catchment scale, is here applied to...

  3. Estimating thermal regimes of bull trout and assessing the potential effects of climate warming on critical habitats

    Science.gov (United States)

    Jones, Leslie A.; Muhlfeld, Clint C.; Marshall, Lucy A.; McGlynn, Brian L.; Kershner, Jeffrey L.

    2013-01-01

    Understanding the vulnerability of aquatic species and habitats under climate change is critical for conservation and management of freshwater systems. Climate warming is predicted to increase water temperatures in freshwater ecosystems worldwide, yet few studies have developed spatially explicit modelling tools for understanding the potential impacts. We parameterized a nonspatial model, a spatial flow-routed model, and a spatial hierarchical model to predict August stream temperatures (22-m resolution) throughout the Flathead River Basin, USA and Canada. Model comparisons showed that the spatial models performed significantly better than the nonspatial model, explaining the spatial autocorrelation found between sites. The spatial hierarchical model explained 82% of the variation in summer mean (August) stream temperatures and was used to estimate thermal regimes for threatened bull trout (Salvelinus confluentus) habitats, one of the most thermally sensitive coldwater species in western North America. The model estimated summer thermal regimes of spawning and rearing habitats at <13 C° and foraging, migrating, and overwintering habitats at <14 C°. To illustrate the useful application of such a model, we simulated climate warming scenarios to quantify potential loss of critical habitats under forecasted climatic conditions. As air and water temperatures continue to increase, our model simulations show that lower portions of the Flathead River Basin drainage (foraging, migrating, and overwintering habitat) may become thermally unsuitable and headwater streams (spawning and rearing) may become isolated because of increasing thermal fragmentation during summer. Model results can be used to focus conservation and management efforts on populations of concern, by identifying critical habitats and assessing thermal changes at a local scale.

  4. Physicochemical Analysis of Water Quality of Brook Kuruçay

    Directory of Open Access Journals (Sweden)

    Ekrem Mutlu

    2016-11-01

    Full Text Available In this study, through the analyses of water samples taken from 9 stations on the brook between July 2012 and June 2013, we aimed to determine the monthly and seasonal changes in water quality parameters of Brook Kuruçay, to determine the water quality properties, to reveal the pollution problems, to determine the suitability level in terms of aquatic life and to classify the quality of water in accordance with Surface Water Quality Management Regulation’s Inland Surface Water Classes criteria. The study area is located southeast of the Hafik District of Sivas city and the altitude is 2608 m. The water samples were collected from 9 stations established on the brook, and some physicochemical parameters and heavy metal concentrations were analyzed in water samples. The cleaning and maintenance of all of the equipment, land-type measurement tools, and glass sampling containers to be used in sampling were made 1 day before sampling. Sampling tubes were immersed into 15 cm below the water surface for taking water samples. Heavy metal concentrations were determined in the Sivas Provincial Control Laboratory in the same day with sampling (within 5 hours. The total alkalinity, total hardness, ammonium nitrogen, nitrite, nitrate, ammonium azote, phosphate, sulfite, sulfate, chloride, sodium, potassium, suspended solid matter (SSM, chemical oxygen demand (COD, biological oxygen demand (BOD, calcium, magnesium, ferrous, lead, copper, zinc, nickel, mercury and cadmium analyses of water samples were performed. As a result of the analyses, it was determined that, since Brook Kuruçay falls into the water resource class, which is the most sensitive to pollution, the water quality of the brook should be monitored regularly.

  5. ERM booster vaccination of Rainbow trout using diluted bacterin

    DEFF Research Database (Denmark)

    Schmidt, Jacob Günther; Henriksen, Niels H.; Buchmann, Kurt

    2016-01-01

    Enteric Red Mouth Disease ERM caused by Yersinia ruckeri infection is associated with morbidity and mortality in salmonid farming but immersion vaccination of fry may confer some protection for a number of months. Revaccination of rainbow trout, even by use of diluted ERM immersion vaccine, can......:10) in April 2015 was followed 3 months later (July 2015) by 1 h bathing of rainbow trout in bacterin (diluted 1:650 or 1:1700) in order to evaluate if this time saving vaccination methodology can improve immunity and protection. Trout were subjected in farms to natural Y. ruckeri exposure in June and July...

  6. TOPMODEL simulations of streamflow and depth to water table in Fishing Brook Watershed, New York, 2007-09

    Science.gov (United States)

    Nystrom, Elizabeth A.; Burns, Douglas A.

    2011-01-01

    TOPMODEL, a physically based, variable-source area rainfall-runoff model, was used to simulate streamflow and depth to water table for the period January 2007-September 2009 in the 65.6 square kilometers of Fishing Brook Watershed in northern New York. The Fishing Brook Watershed is located in the headwaters of the Hudson River and is predominantly forested with a humid, cool continental climate. The motivation for applying this model at Fishing Brook was to provide a simulation that would be effective later at this site in modeling the interaction of hydrologic processes with mercury dynamics.

  7. Admixture analysis of stocked brown trout populations using mapped microsatellite DNA markers: indigenous trout persist in introgressed populations

    DEFF Research Database (Denmark)

    Hansen, Michael Møller; Mensberg, Karen-Lise Dons

    2009-01-01

    a high number of microsatellite DNA markers (50) and making use of linkage map information, we achieve clear identification of admixed and non-admixed trout. Moreover, despite strong population-level admixture by hatchery strain trout in one of the populations (70.8%), non-admixed individuals...... nevertheless persist (7 out of 53 individuals). These remnants of the indigenous population are characterized by later spawning time than the majority of the admixed individuals. We hypothesize that isolation by time mediated by spawning time differences between wild and hatchery strain trout is a major factor...

  8. Brown Trout Distribution, Pacific Northwest (updated March, 2006)

    Data.gov (United States)

    Pacific States Marine Fisheries Commission — This dataset is a record of fish distribution and activity for BROWN TROUT contained in the StreamNet database. This feature class was created based on linear event...

  9. Rainbow Trout Distribution, Pacific Northwest (updated March, 2006)

    Data.gov (United States)

    Pacific States Marine Fisheries Commission — This dataset is a record of fish distribution and activity for RAINBOW TROUT contained in the StreamNet database. This feature class was created based on linear...

  10. Yellowstone Cutthroat Trout Distribution, Pacific Northwest (updated March, 2006)

    Data.gov (United States)

    Pacific States Marine Fisheries Commission — This dataset is a record of fish distribution and activity for YELLOWSTONE CUTTHROAT TROUT contained in the StreamNet database. This feature class was created based...

  11. Redband Trout Distribution, Pacific Northwest (updated March, 2006)

    Data.gov (United States)

    Pacific States Marine Fisheries Commission — This dataset is a record of fish distribution and activity for REDBAND TROUT contained in the StreamNet database. This feature class was created based on linear...

  12. Westslope Cutthroat Trout Distribution, Pacific Northwest (updated March, 2006)

    Data.gov (United States)

    Pacific States Marine Fisheries Commission — This dataset is a record of fish distribution and activity for WESTSLOPE CUTTHROAT TROUT contained in the StreamNet database. This feature class was created based on...

  13. Bull Trout Distribution, Pacific Northwest (updated March, 2006)

    Data.gov (United States)

    Pacific States Marine Fisheries Commission — This dataset is a record of fish distribution and activity for BULL TROUT contained in the StreamNet database. This feature class was created based on linear event...

  14. Lahontan Cutthroat Trout Distribution, Pacific Northwest (updated March, 2006)

    Data.gov (United States)

    Pacific States Marine Fisheries Commission — This dataset is a record of fish distribution and activity for LAHONTAN CUTTHROAT TROUT contained in the StreamNet database. This feature class was created based on...

  15. 2006 Reson 8101ER Multibeam Sonar Data from Cruise AHI-06-12 - Brooks Bank, Northwestern Hawaiian Islands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Reson 8101ER multibeam Data were collected between 13-15 October 2006 aboard NOAA Survey Launch Acoustic Habitat Investigator (AHI) Brooks Banks in the Northwestern...

  16. CRED 20 m Gridded bathymetry of Brooks Banks and St. Rogatien Bank, Hawaii, USA (Arc ASCII format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry (20m) of the shelf and slope environments of Brooks Banks and St. Rogatien, Hawaii, USA. The ASCII includes multibeam bathymetry from the Simrad...

  17. A Comparison of Some Aspects of Two Extinct Mammals, Mammuthus Brookes, 1828 (Proboscidea: Elephantidae) and Mammut Blumenbach, 1799 (Proboscidea: Mammutidae)

    National Research Council Canada - National Science Library

    Pankaj S. Bhatnagar

    2013-01-01

    The present study aims at extracting the fossil database www.paleodb.org to compare extinct megafauna genera, Mammuthus Brookes, 1828 and Mammut Blumenbach, 1799 along with its close reletive, Zygolophodon (Vacek, 1877...

  18. Nonnative trout invasions combined with climate change threaten persistence of isolated cutthroat trout populations in the southern Rocky Mountains

    Science.gov (United States)

    Roberts, James J.; Kurt D. Fausch,; Hooten, Mevin B.; Peterson, Douglas P.

    2017-01-01

    Effective conservation of Cutthroat Trout Oncorhynchus clarkii lineages native to the Rocky Mountains will require estimating effects of multiple stressors and directing management toward the most important ones. Recent

  19. AEROMONAS SALMONICIDA INFECTION IN VACCINATED RAINBOW TROUT

    DEFF Research Database (Denmark)

    Chettri, Jiwan Kumar; Skov, Jakob; Mohammad, Rezkar Jaafar

    to that of the commercial vaccine with lower side effects as observed by the Speilberg scoring system. Gene expression analysis did not show a clear trend for Th1 or Th2 response in the vaccinated fish. Exposure of fish to saltwater increased the IgT production. Overall, the immune response in vaccinated fish, the side......In vivo testing of any candidate vaccine is influenced by the choice of challenge method and the external environmental conditions. In the present study, a comparative challenge study was performed to evaluate the efficacy of different vaccines against the bacterial pathogen Aeromonas salmonicida...... causing furunculosis. Rainbow trout (Oncorhynchus mykiss) were vaccinated with two trivalent adjuvanted experimental vaccines containing formalin-killed A. salmonicida, Vibrio anguillarum O1 and O2a and a commercial corresponding vaccine (Alpha Ject 3000). Fish were challenged by i.p. injection...

  20. Effects of hybridization between nonnative Rainbow Trout and native Westslope Cutthroat Trout on fitness-related traits

    Science.gov (United States)

    Drinan, Daniel P.; Webb, Molly A. H.; Naish, Kerry A.; Kalinowski, Steven T.; Boyer, Matthew C.; Steed, Amber C.; Shepard, Bradley B.; Muhlfeld, Clint C.

    2015-01-01

    Hybridization between introduced and native fauna is a risk to native species and may threaten the long-term persistence of numerous taxa. Rainbow Trout Oncorhynchus mykiss has been one of the most widely introduced species around the globe and often hybridizes with native Cutthroat Trout O. clarkii in the Rocky Mountains. Previous work has shown that hybridization negatively affects reproductive success, but identification of the traits contributing to that reduction has been elusive. In this study, we used a combination of field and laboratory techniques to assess how hybridization with Rainbow Trout affects seven traits during several stages of Westslope Cutthroat Trout development: embryonic survival, ova size, ova energy concentration, sperm motility, juvenile weight, juvenile survival, and burst swimming endurance. Rainbow Trout admixture was correlated with an increase in embryonic survival and ova energy concentration but with a decrease in juvenile weight and burst swimming endurance. These correlations differed from previously observed patterns of reproductive success and likely do not explain the declines in reproductive success associated with admixture. Future investigation of additional, unstudied traits and the use of different environments may shed light on the traits responsible for reproductive success in admixed Cutthroat Trout.

  1. Intracellular diffusion restrictions in isolated cardiomyocytes from rainbow trout

    Directory of Open Access Journals (Sweden)

    Birkedal Rikke

    2009-12-01

    Full Text Available Abstract Background Restriction of intracellular diffusion of adenine nucleotides has been studied intensively on adult rat cardiomyocytes. However, their cause and role in vivo is still uncertain. Intracellular membrane structures have been suggested to play a role. We therefore chose to study cardiomyocytes from rainbow trout (Oncorhynchus mykiss, which are thinner and have fewer intracellular membrane structures than adult rat cardiomyocytes. Previous studies suggest that trout permeabilized cardiac fibers also have diffusion restrictions. However, results from fibers may be affected by incomplete separation of the cells. This is avoided when studying permeabilized, isolated cardiomyocytes. The aim of this study was to verify the existence of diffusion restrictions in trout cardiomyocytes by comparing ADP-kinetics of mitochondrial respiration in permeabilized fibers, permeabilized cardiomyocytes and isolated mitochondria from rainbow trout heart. Experiments were performed at 10, 15 and 20°C in the absence and presence of creatine. Results Trout cardiomyocytes hypercontracted in the solutions used for mammalian cardiomyocytes. We developed a new solution in which they retained their shape and showed stable steady state respiration rates throughout an experiment. The apparent ADP-affinity of permeabilized cardiomyocytes was different from that of fibers. It was higher, independent of temperature and not increased by creatine. However, it was still about ten times lower than in isolated mitochondria. Conclusions The differences between fibers and cardiomyocytes suggest that results from trout heart fibers were affected by incomplete separation of the cells. However, the lower ADP-affinity of cardiomyocytes compared to isolated mitochondria indicate that intracellular diffusion restrictions are still present in trout cardiomyocytes despite their lower density of intracellular membrane structures. The lack of a creatine effect indicates that

  2. X-linked mental retardation syndrome: Three brothers with the Brooks-Wisniewski-Brown syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Morava, E.; Storcz, J.; Kosztolanyi, G. [Univ. Medical School, Pecs (Hungary)

    1996-07-12

    We report on 3 brothers with growth and mental retardation, bifrontal narrowness, short palpebral fissures, deeply set eyes with entropion, wide bulbous nose, small mouth, myopia, and spastic diplegia. The patients were born to normal and non-consanguineous parents. The similarity of our cases with those recently reported by Brooks et al. supports their suggestion that these patients are representative of a distinct entity. 8 refs., 3 figs., 1 tab.

  3. Field performance of timber bridges. 10, Sanborn Brook stress-laminated deck bridge

    Science.gov (United States)

    P. D. Hilbrich Lee; J. P. Wacker; M. A. Ritter

    The Sanborn Brook bridge was constructed in August 1991, 10 miles northeast of Concord, New Hampshire, as part of the demonstration timber bridge program of the USDA Forest Service. The bridge is a simple-span, double-lane, stress-laminated deck superstructure constructed from Southern Pine lumber and is approximately 25 ft long and 28 ft wide with a skew of 14 degrees...

  4. Focus on: University Hospital & Health Sciences Center SUNY at Stony Brook Biomedical Engineering Department.

    Science.gov (United States)

    Dyro, J F

    1993-01-01

    Clinical Engineering is practiced within the Biomedical Engineering Department (BME) at University Hospital, a modern, 536-bed, tertiary care teaching hospital. The 30-member department delivers a full range of clinical engineering services within the Stony Brook academic medical center. Major clinical engineering advances have been made in the areas of technology management, productivity and cost effectiveness, medical device safety, education, and research. University Hospital provides care for 2.5 million people in Suffolk County and other parts of Long Island.

  5. Age and correlation of the Otuk formation, North-Central Brooks Range, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Bodnar, K.A.; Mull, C.G.

    1985-04-01

    Allochthonous Triassic rocks of the north-central Brooks Range thrust belt were originally mapped as part of the Middle to Upper Triassic Shublik Formation. Recently, these strata were named the Otuk Formation. Detailed paleontologic studies of 11 measured sections more precisely document the age of the Otuk and show that its base is older than the base of the Shublik and that its top is younger than the top of the Shublik. Megafossils (pelecypods and ammonites) and microfossils (radiolaria, conodonts, and foraminifers) indicate an age range of Early Triassic (Dienerian-Smithian or older) to Middle Jurassic (Bajocian). The lithology consists of 120 m (390 ft) of interbedded, very fine-grained rocks (shale, limestone, and chert) representative of very slow deposition, below wave base in an open marine environment. The Otuk formation does not contain suitable reservoir rocks, but organic geochemical data indicate that the shales are possible oil source rocks. The Otuk formation is disconformable with both the underlying Permian (Wolfcampian-Guadalupian) Siksikpuk Formation and overlying Lower Cretaceous (Valanginian) coquinoid limestone and shale. These unconformities are correlative with similar unconformities in the northeastern Brooks Range and subsurface of the North Slope. Thus, the Otuk formation is a condensed, deeper water, more distal equivalent of the Ivishak and Shublik Formations, Karen Creek Sandstone, and lower Kingak Shale of the northeastern Brooks Range and equivalent subsurface units of the North Slope.

  6. Amoxicillin pulsatile - MiddleBrook: APC 111, APC-111, PULSYS-enhanced amoxicillin.

    Science.gov (United States)

    2007-01-01

    MiddleBrook Pharmaceuticals (formerly Advancis Pharmaceutical) is developing an improved version of amoxicillin using its pulsatile oral drug delivery technology, called PULSYS. Amoxicillin PULSYS is intended to provide a lower treatment dose, once-daily alternative to currently approved amoxicillin and penicillin regimens for the treatment of adolescents/adults with pharyngitis and/or tonsillitis. If amoxicillin PULSYS is approved, it will be the first and only once-daily amoxicillin therapy approved for use in the US. Regulatory submissions for the treatment of pharyngitis/tonsillitis have been made in the US. Amoxicillin PULSYS is in clinical development for the treatment of pharyngitis and/or tonsillitis due to group A streptococcal infections in adolescents/adults as a tablet formulation. MiddleBrook was conducting clinical development of a sprinkle formulation for children. However, this has been put on hold for financial reasons. MiddleBrook is seeking regulatory approval for this product as a 505(b)(2) product, which is one that is not considered to be a completely new product, but is also not a generic product. It is a product with some differences from a previously approved product and clinical data to support such differences are required; however, the basic safety and efficacy studies may have been conducted by other organisations. In June 2007, Advancis Pharmaceutical was renamed as MiddleBrook Pharmaceuticals, Inc. MiddleBrook and Par Pharmaceuticals entered a co-promotion agreement for this product in June 2004. Par was to fund future development in exchange for co-exclusive marketing rights and exclusive rights to sell amoxicillin PULSYS. MiddleBrook retained responsibility for the manufacturing programme and also retained all patents and brand names and was responsible for their enforcement. However, this collaboration was subsequently terminated in August 2005 by Par Pharmaceutical. MiddleBrook received the US $4.75 million R&D reimbursement

  7. Restoration of Soldier Spring: an isolated habitat for native Apache trout

    Science.gov (United States)

    Jonathan W. Long; B. Mae Burnette; Alvin L. Medina; Joshua L. Parker

    2004-01-01

    Degradation of streams is a threat to the recovery of the Apache trout, an endemic fish of the White Mountains of Arizona. Historic efforts to improve trout habitat in the Southwest relied heavily on placement of in-stream log structures. However, the effects of structural interventions on trout habitat and populations have not been adequately evaluated. We treated an...

  8. Exploring trends, causes, and consequences of declining lipids in Lake Superior lake trout

    Science.gov (United States)

    The ability of lake trout to forage in deepwater habitats is facilitated by high lipid content, which affords buoyancy. In Lake Superior, lean lake trout historically occupied depths < 80 m, and siscowet lake trout occupied depths > 80 m. Siscowets have been known f...

  9. A value orientation approach to assess and compare climate change risk perception among trout anglers in Georgia, USA

    Science.gov (United States)

    Ramesh Paudyal; Neelam C. Poudyal; J.M. Bowker; Adrienne M. Dorison; Stanley J. Zarnoch; Gary T. Green

    2015-01-01

    Trout in Georgia could experience early impacts from climate change as the streams in the region are located at the southern most edge of their North American home range. This study surveyed trout anglers in Georgia to understand how anglers perceive the potential impact of climate change on trout, and whether and how their perception and response to declines in trout...

  10. Central ventilatory and cardiovascular actions of trout gastrin-releasing peptide (GRP in the unanesthetized trout

    Directory of Open Access Journals (Sweden)

    Jean-Claude Le Mével

    2013-07-01

    Gastrin-releasing peptide (GRP, a neuropeptide initially isolated from porcine stomach, shares sequence similarity with bombesin. GRP and its receptors are present in the brains and peripheral tissues of several species of teleost fish, but little is known about the ventilatory and cardiovascular effects of this peptide in these vertebrates. The goal of this study was to compare the central and peripheral actions of picomolar doses of trout GRP on ventilatory and cardiovascular variables in the unanesthetized rainbow trout. Compared to vehicle, intracerebroventricular (ICV injection of GRP (1–50 pmol significantly elevated the ventilation rate (ƒV and the ventilation amplitude (VAMP, and consequently the total ventilation (VTOT. The maximum hyperventilatory effect of GRP (VTOT: +225%, observed at a dose of 50 pmol, was mostly due to its stimulatory action on VAMP (+170% rather than ƒV (+20%. In addition, ICV GRP (50 pmol produced a significant increase in mean dorsal aortic blood pressure (PDA (+35% and in heart rate (ƒH (+25%. Intra-arterial injections of GRP (5–100 pmol were without sustained effect on the ventilatory variables but produced sporadic and transient increases in ventilatory movement at doses of 50 and 100 pmol. At these doses, GRP elevated PDA by +20% but only the 50 pmol dose significantly increased HR (+15%. In conclusion, our study suggests that endogenous GRP within the brain of the trout may act as a potent neurotransmitter and/or neuromodulator in the regulation of cardio-ventilatory functions. In the periphery, endogenous GRP may act as locally-acting and/or circulating neurohormone with an involvement in vasoregulatory mechanisms.

  11. 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.

  12. Characterization of p53 expression in rainbow trout.

    Science.gov (United States)

    Liu, Michelle; Tee, Catherine; Zeng, Fanxing; Sherry, James P; Dixon, Brian; Bols, Niels C; Duncker, Bernard P

    2011-11-01

    The tumour suppressor protein p53 is a critical component of cell cycle checkpoint responses. It upregulates the expression of cyclin-dependent kinase inhibitors in response to DNA damage and other cellular perturbations, and promotes apoptosis when DNA repair pathways are overwhelmed. Given the high incidence of p53 mutations in human cancers, it has been extensively studied, though only a small fraction of these investigations have been in non-mammalian systems. For the present study, an anti-rainbow trout p53 polyclonal antibody was generated. A variety of rainbow trout (Oncorhynchus mykiss) tissues and cell lines were examined through western blot analysis of cellular protein extracts, which revealed relatively high p53 levels in brain and gills. To evaluate the checkpoint response of rainbow trout p53, RTbrain-W1 and RTgill-W1 cell lines were exposed to varying concentrations of the DNA damaging agent bleomycin and ribonucleotide reductase inhibitor hydroxyurea. In contrast to mammals, these checkpoint-inducing agents provoked no apparent increase in rainbow trout p53 levels. These results infer the presence of alternate DNA damage checkpoint mechanisms in rainbow trout cells. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. Indirect benefits for female salmon from mating with brown trout.

    Science.gov (United States)

    Castillo, Ana G F; Beall, Edward; Morán, Paloma; Martinez, Jose L; Garcia-Vazquez, Eva

    2010-01-01

    By genetic analysis of 1625 samples from 10 south European rivers, we have found that Atlantic salmon Salmo salar hybridize with sympatric brown trout S. trutta in the wild and provide the female in most heterospecific crosses. Hybrids exhibit reduced fertility and could be considered a wasted reproductive effort by salmon females. In 7 experiments involving salmon females, large brown trout males, and small salmon male sneakers, reproductive success of Atlantic salmon females mating with brown trout males was not significantly different from that of 5 experiments of females mating with conspecific males because small Atlantic salmon sneakers fertilized most ova (mean 93%) in salmon x trout matings. Although egg retention tended to be higher in heterospecific than in conspecific crosses (mean 5.7% vs. 20.5% respectively), mean offspring survival was 24.4% and 30.3%, respectively (t = 1.5 x 10(-8), not significant). Brown trout males taking on a courting role may benefit late-maturing females in absence or scarcity of anadromous salmon males because they play a protective role against disturbances from other fishes (including cannibal sneakers).

  14. 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

  15. Unraveling the Timing of Fluid Migration and Trap Formation in the Brooks Range Foothills: A Key to Discovering Hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Catherine L. Hanks

    2008-12-31

    Naturally occurring fractures can play a key role in the evolution and producibility of a hydrocarbon accumulation. Understanding the evolution of fractures in the Brooks Range/Colville basin system of northern Alaska is critical to developing a better working model of the hydrocarbon potential of the region. This study addressed this problem by collecting detailed and regional data on fracture distribution and character, structural geometry, temperature, the timing of deformation along the Brooks Range rangefront and adjacent parts of the Colville basin, and the in situ stress distribution within the Colville basin. This new and existing data then were used to develop a model of how fractures evolved in northern Alaska, both spatially and temporally. The results of the study indicate that fractures formed episodically throughout the evolution of northern Alaska, due to a variety of mechanisms. Four distinct fracture sets were observed. The earliest fractures formed in deep parts of the Colville basin and in the underlying Ellesmerian sequence rocks as these rocks experienced compression associated with the growing Brooks Range fold-and-thrust belt. The orientation of these deep basin fractures was controlled by the maximum in situ horizontal stress in the basin at the time of their formation, which was perpendicular to the active Brooks Range thrust front. This orientation stayed consistently NS-striking for most of the early history of the Brooks Range and Colville basin, but changed to NW-striking with the development of the northeastern Brooks Range during the early Tertiary. Subsequent incorporation of these rocks into the fold-and-thrust belt resulted in overprinting of these deep basin fractures by fractures caused by thrusting and related folding. The youngest fractures developed as rocks were uplifted and exposed. While this general order of fracturing remains consistent across the Brooks Range and adjacent Colville basin, the absolute age at any one

  16. The marine life of sea trout (Salmo trutta)

    DEFF Research Database (Denmark)

    Del Villar, Diego

    -smolts as well as on the fish returning to freshwater after the marine stage. The results of my experiments increase the current knowledge of specific behavioural traits that sea trout displays during their marine life. Additionally, it provides new information on the early and late marine survival which......During my PhD. research project I have studied the marine migratory behaviour and survival of wild sea trout (Salmo trutta L.) juveniles when moving from freshwater to saltwater (i.e. smolts/post-smolts) in two different fjord systems. These studies are focused on the initial marine stage of post...... is needed for comprehensive management of sea trout populations in the area. The principal method used was telemetry (acoustic and PIT-telemetry) which enable studying migratory patterns of fish in the fjord (i.e. acoustic telemetry) and detecting the transitions from the marine to the riverine environments...

  17. Epidermal response of rainbow trout to Ichthyobodo necator

    DEFF Research Database (Denmark)

    Chettri, Jiwan Kumar; Kuhn, Jesper Andreas; Mohammad, Rezkar Jaafar

    2014-01-01

    Infections with the parasitic flagellate Ichthyobodo necator (Henneguy, 1883) cause severe skin and gill disease in rainbow trout Oncorhynchus mykiss (Walbaum, 1792) juveniles. The epidermal disturbances including hyperplasia and mucous cell exhaustion caused by parasitization are known, but no d......Infections with the parasitic flagellate Ichthyobodo necator (Henneguy, 1883) cause severe skin and gill disease in rainbow trout Oncorhynchus mykiss (Walbaum, 1792) juveniles. The epidermal disturbances including hyperplasia and mucous cell exhaustion caused by parasitization are known...... an experimental infection of juvenile rainbow trout. The course of infection was followed by sampling for parasite enumeration, immunohistochemistry (IHC) and quantitative PCR (qPCR) on days 0, 5, 9 and 14 post-infection. IHC showed a significant increase in the occurrence of IgM-positive cells in the skin...

  18. 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.

  19. The developmental transcriptome of contrasting Arctic charr (Salvelinus alpinus morphs [version 2; referees: 1 approved, 2 approved with reservations

    Directory of Open Access Journals (Sweden)

    Johannes Gudbrandsson

    2016-04-01

    Full Text Available Species and populations with parallel evolution of specific traits can help illuminate how predictable adaptations and divergence are at the molecular and developmental level. Following the last glacial period, dwarfism and specialized bottom feeding morphology evolved rapidly in several landlocked Arctic charr Salvelinus alpinus populations in Iceland.   To study the genetic divergence between small benthic morphs and limnetic morphs, we conducted RNA-sequencing charr embryos at four stages in early development. We studied two stocks with contrasting morphologies: the small benthic (SB charr from Lake Thingvallavatn and Holar aquaculture (AC charr. The data reveal significant differences in expression of several biological pathways during charr development. There was also an expression difference between SB- and AC-charr in genes involved in energy metabolism and blood coagulation genes. We confirmed differing expression of five genes in whole embryos with qPCR, including lysozyme and natterin-like which was previously identified as a fish-toxin of a lectin family that may be a putative immunopeptide. We also verified differential expression of 7 genes in the developing head that associated consistently with benthic v.s.limnetic morphology (studied in 4 morphs. Comparison of single nucleotide polymorphism (SNP frequencies reveals extensive genetic differentiation between the SB and AC-charr (~1300 with more than 50% frequency difference. Curiously, three derived alleles in the otherwise conserved 12s and 16s mitochondrial ribosomal RNA genes are found in benthic charr. The data implicate multiple genes and molecular pathways in divergence of small benthic charr and/or the response of aquaculture charr to domestication. Functional, genetic and population genetic studies on more freshwater and anadromous populations are needed to confirm the specific loci and mutations relating to specific ecological traits in Arctic charr.

  20. The developmental transcriptome of contrasting Arctic charr (Salvelinus alpinus morphs [version 3; referees: 1 approved, 2 approved with reservations

    Directory of Open Access Journals (Sweden)

    Johannes Gudbrandsson

    2016-12-01

    Full Text Available Species and populations with parallel evolution of specific traits can help illuminate how predictable adaptations and divergence are at the molecular and developmental level. Following the last glacial period, dwarfism and specialized bottom feeding morphology evolved rapidly in several landlocked Arctic charr Salvelinus alpinus populations in Iceland.   To study the genetic divergence between small benthic morphs and limnetic morphs, we conducted RNA-sequencing charr embryos at four stages in early development. We studied two stocks with contrasting morphologies: the small benthic (SB charr from Lake Thingvallavatn and Holar aquaculture (AC charr. The data reveal significant differences in expression of several biological pathways during charr development. There was also an expression difference between SB- and AC-charr in genes involved in energy metabolism and blood coagulation genes. We confirmed differing expression of five genes in whole embryos with qPCR, including lysozyme and natterin-like which was previously identified as a fish-toxin of a lectin family that may be a putative immunopeptide. We also verified differential expression of 7 genes in the developing head that associated consistently with benthic v.s.limnetic morphology (studied in 4 morphs. Comparison of single nucleotide polymorphism (SNP frequencies reveals extensive genetic differentiation between the SB and AC-charr (~1300 with more than 50% frequency difference. Curiously, three derived alleles in the otherwise conserved 12s and 16s mitochondrial ribosomal RNA genes are found in benthic charr. The data implicate multiple genes and molecular pathways in divergence of small benthic charr and/or the response of aquaculture charr to domestication. Functional, genetic and population genetic studies on more freshwater and anadromous populations are needed to confirm the specific loci and mutations relating to specific ecological traits in Arctic charr.

  1. Developing a food web-based transfer factor of radiocesium for fish, whitespotted char (Salvelinus leucomaenis) in headwater streams.

    Science.gov (United States)

    Haque, Md Enamul; Gomi, Takashi; Sakai, Masaru; Negishi, Junjiro N

    2017-06-01

    We developed a food web-based transfer factor (TFweb) to study contaminant movements from multiple prey items to a predator based on the dietary contributions of prey items with their respective contamination levels. TFweb was used to evaluate the transfer of 137Cs into whitespotted char (Salvelinus leucomaenis) from the trophic structure of a stream-riparian ecosystem in headwater streams draining a Japanese cedar forest. We also examined the applicability of this method by comparing sites with different contamination levels but similar surrounding environments in Fukushima and Gunma. All samples were collected from August 2012 to May 2013. The dietary contributions from both aquatic and terrestrial prey items to whitespotted char were analyzed using stable carbon and nitrogen isotope ratios. 137Cs activity concentrations in char ranged from 704 to 6082 Bq kg-1-dry in Fukushima and from 193 to 618 Bq kg-1-dry in Gunma. Dominant prey taxa such as mayflies (Ephemera japonica), spider crickets (Rhaphidosphoridae gen. spp.), and freshwater crabs (Geothelphusa dehaani), each of them accounted for 3-12% of the fish diet, based on lower and upper estimates, respectively. TFweb ranged from 1.12 to 3.79 in Fukushima and from 1.30 to 4.30 in Gunma, which suggested bioaccumulation from prey items to predator. Widely used ecological parameters TFs by media-char and TTF by single prey-char showed high variability with both dilution and accumulation. TFweb is applicable for 137Cs transfer in predator-prey systems with complex food web structures of stream-riparian ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. A new species of Potamotrygonocestus Brooks & Thorson, 1976 (Eucestoda: Tetraphyllidea) from Plesiotrygon iwamae Rosa, Castello & Thorson (Mylliobatoidea: Potamotrygonidae) and a redescription of Potamotrygonocestus chaoi Marques, Brooks & Araujo, 2003.

    Science.gov (United States)

    Luchetti, N M; Marques, F P L; Charvet-Almeida, P

    2008-06-01

    Potamotrygonocestus Brooks & Thorson, 1976 is currently represented by six recognised species of tetraphyllidean cestodes inhabiting Neotropical freshwater stingrays. Potamotrygonid stingrays examined to date have included only a single specimen of Plesiotrygon iwamae. Only one species of tetraphyllidean, Potamotrygonocestus chaoi Marques, Brooks & Araujo, 2003, has been described from this host, and this description was based on limited material. New efforts to document the diversity in this host species resulted in the collection of eight additional specimens of P. iwamae, one of these from the upper Rio Solimões, at São Paulo de Olivença Amazonas during September, 2003, and seven from the Baía do Marajó, Pará, during November, 2003. The specimen from the upper Solimões was found to be infected with P. chaoi. Voucher material from this stingray was used for the redescription of this cestode, which is characterized by strobila 8.78-22.83 mm long and a great number of proglottides, 58-93; the new material provided strobilar length and proglottis counts for complete worms. Potamotrygonocestus marajoara n. sp. is the second species of this genus reported from Plesiotrygon iwamae, although it appears to be restricted to the lower Amazon. This new species resembles P. chaoi in possessing filitriches and blade-like spinitriches on the scolex, cephalic peduncle and cirrus, but differs from other species of the genus in the number of testes, which is 44 on average per proglottis, and by having apical sucker measuring 95-175 microm in length. Additional data on the distribution and morphology of the microtriches and a detailed description of the female reproductive system are also provided in this study.

  3. A first generation integrated map of the rainbow trout genome

    Directory of Open Access Journals (Sweden)

    Tabet-Canale Kamila

    2011-04-01

    Full Text Available Abstract Background Rainbow trout (Oncorhynchus mykiss are the most-widely cultivated cold freshwater fish in the world and an important model species for many research areas. Coupling great interest in this species as a research model with the need for genetic improvement of aquaculture production efficiency traits justifies the continued development of genomics research resources. Many quantitative trait loci (QTL have been identified for production and life-history traits in rainbow trout. An integrated physical and genetic map is needed to facilitate fine mapping of QTL and the selection of positional candidate genes for incorporation in marker-assisted selection (MAS programs for improving rainbow trout aquaculture production. Results The first generation integrated map of the rainbow trout genome is composed of 238 BAC contigs anchored to chromosomes of the genetic map. It covers more than 10% of the genome across segments from all 29 chromosomes. Anchoring of 203 contigs to chromosomes of the National Center for Cool and Cold Water Aquaculture (NCCCWA genetic map was achieved through mapping of 288 genetic markers derived from BAC end sequences (BES, screening of the BAC library with previously mapped markers and matching of SNPs with BES reads. In addition, 35 contigs were anchored to linkage groups of the INRA (French National Institute of Agricultural Research genetic map through markers that were not informative for linkage analysis in the NCCCWA mapping panel. The ratio of physical to genetic linkage distances varied substantially among chromosomes and BAC contigs with an average of 3,033 Kb/cM. Conclusions The integrated map described here provides a framework for a robust composite genome map for rainbow trout. This resource is needed for genomic analyses in this research model and economically important species and will facilitate comparative genome mapping with other salmonids and with model fish species. This resource will also

  4. Chromosome rearrangements, recombination suppression, and limited segregation distortion in hybrids between Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) and rainbow trout (O. mykiss).

    Science.gov (United States)

    Ostberg, Carl O; Hauser, Lorenz; Pritchard, Victoria L; Garza, John C; Naish, Kerry A

    2013-08-22

    Introgressive hybridization is an important evolutionary process that can lead to the creation of novel genome structures and thus potentially new genetic variation for selection to act upon. On the other hand, hybridization with introduced species can threaten native species, such as cutthroat trout (Oncorhynchus clarkii) following the introduction of rainbow trout (O. mykiss). Neither the evolutionary consequences nor conservation implications of rainbow trout introgression in cutthroat trout is well understood. Therefore, we generated a genetic linkage map for rainbow-Yellowstone cutthroat trout (O. clarkii bouvieri) hybrids to evaluate genome processes that may help explain how introgression affects hybrid genome evolution. The hybrid map closely aligned with the rainbow trout map (a cutthroat trout map does not exist), sharing all but one linkage group. This linkage group (RYHyb20) represented a fusion between an acrocentric (Omy28) and a metacentric chromosome (Omy20) in rainbow trout. Additional mapping in Yellowstone cutthroat trout indicated the two rainbow trout homologues were fused in the Yellowstone genome. Variation in the number of hybrid linkage groups (28 or 29) likely depended on a Robertsonian rearrangement polymorphism within the rainbow trout stock. Comparison between the female-merged F₁ map and a female consensus rainbow trout map revealed that introgression suppressed recombination across large genomic regions in 5 hybrid linkage groups. Two of these linkage groups (RYHyb20 and RYHyb25_29) contained confirmed chromosome rearrangements between rainbow and Yellowstone cutthroat trout indicating that rearrangements may suppress recombination. The frequency of allelic and genotypic segregation distortion varied among parents and families, suggesting few incompatibilities exist between rainbow and Yellowstone cutthroat trout genomes. Chromosome rearrangements suppressed recombination in the hybrids. This result supports several previous

  5. Spatial and temporal consumption dynamics of trout in catch-and-release areas in Arkansas tailwaters

    Science.gov (United States)

    Flinders, John M.; Magoulick, Daniel D.

    2017-01-01

    Restrictive angling regulations in tailwater trout fisheries may be unsuccessful if food availability limits energy for fish to grow. We examined spatial and temporal variation in energy intake and growth in populations of Brown Trout Salmo trutta and Rainbow Trout Oncorhynchus mykiss within three catch-and-release (C-R) areas in Arkansas tailwaters to evaluate food availability compared with consumption. Based on bioenergetic simulations, Rainbow Trout fed at submaintenance levels in both size-classes (≤400 mm TL, >400 mm TL) throughout most seasons. A particular bottleneck in food availability occurred in the winter for Rainbow Trout when the daily ration was substantially below the minimum required for maintenance, despite reduced metabolic costs associated with lower water temperatures. Rainbow Trout growth rates followed a similar pattern to consumption with negative growth rates during the winter periods. All three size-classes (400 mm TL) of Brown Trout experienced high growth rates and limited temporal bottlenecks in food availability. We observed higher mean densities for Rainbow Trout (47–342 fish/ha) than for Brown Trout (3–84 fish/ha) in all C-R areas. Lower densities of Brown Trout coupled with an ontogenetic shift towards piscivory may have allowed for higher growth rates and sufficient consumption rates to meet energetic demands. Brown Trout at current densities were more effective in maintaining adequate growth rates and larger sizes in C-R areas than were Rainbow Trout. Bioenergetic simulations suggest that reducing stocking levels of Rainbow Trout in the tailwaters may be necessary in order to achieve increased catch rates of larger trout in the C-R areas.

  6. Animal welfare in brown trout farming: hematological results

    Directory of Open Access Journals (Sweden)

    G. Forneris

    2010-01-01

    Full Text Available The effect of stress resulting from fish farming has received considerable attention in this last period and fish welfare in aquaculture is a relevant topic, very important for the future of aquaculture (Watson et al., 2004; Klinger et al., 1996; Peres et al., 2004; Ron et al., 1995;Wagner et al., 1995;Watson et al., 1998. Brown trout farming is less developed then rainbow trout farming, but this kind of fish farming is increasing, mainly for fish conservation and restocking aquaculture.

  7. Immunity to rhabdoviruses in rainbow trout: the antibody response

    DEFF Research Database (Denmark)

    Lorenzen, Niels; Lapatra, S.E.

    1999-01-01

    to their occasional detrimental effect on rainbow trout farming. Research efforts have been focused on understanding the mechanisms involved in protective immunity. Several specific and nonspecific cellular and humoral parameters are believed to be involved, but only the antibody response has been characterised......, have demonstrated that rainbow trout can produce specific and highly functional antibodies that are able to neutralise virus pathogenicity in vitro as well as in vivo. The apparently more restricted antibody response to IHNV and VHSV antigens in fish compared to mammals could possibly be explained...

  8. Thermal Vacuum Testing of ICPTA RCS at Plum Brook B-2

    Science.gov (United States)

    Atwell, M. J.; Hurlbert, E. A.; Melcher, J. C.; Morehead, R. L.

    2017-01-01

    Vacuum and thermal vacuum testing of the Integrated Cryogenic Propulsion Test Article (ICPTA) was performed at the Plum Brook B-2 facility as a part of a system checkout and facility characterization effort. Multiple test objectives included: integrated Reaction Control System (RCS) characterization, cold helium pressurization system characterization, modal propellant gaging experiment (Orion), CFM propellant loading experiments, main engine characterization. The ICPTA is a test bed for LOX/LCH4 technologies built in 2016 using new components and hardware from the former Morpheus vehicle and other projects.

  9. Systematics and diversification of Anindobothrium Marques, Brooks & Lasso, 2001 (Eucestoda: Rhinebothriidea).

    Science.gov (United States)

    Trevisan, Bruna; Primon, Juliana F; Marques, Fernando P L

    2017-01-01

    Tapeworms of the genus Anindobothrium Marques, Brooks & Lasso, 2001 are found in both marine and Neotropical freshwater stingrays of the family Potamotrygonidae. The patterns of host association within the genus support the most recent hypothesis about the history of diversification of potamotrygonids, which suggests that the ancestor of freshwater lineages of the Potamotrygonidae colonized South American river systems through marine incursion events. Despite the relevance of the genus Anindobothrium to understand the history of colonization and diversification of potamotrygonids, no additional efforts were done to better investigate the phylogenetic relationship of this taxon with other lineages of cestodes since its erection. This study is a result of recent collecting efforts to sample members of the genus in marine and freshwater potamotrygonids that enabled the most extensive documentation of the fauna of Anindobothrium parasitizing species of Styracura de Carvalho, Loboda & da Silva, Potamotrygon schroederi Fernández-Yépez, P. orbignyi (Castelnau) and P. yepezi Castex & Castello from six different countries, representing the eastern Pacific Ocean, Caribbean Sea, and river basins in South America (Rio Negro, Orinoco, and Maracaibo). The newly collected material provided additional specimens for morphological studies and molecular samples for subsequent phylogenetic analyses that allowed us to address the phylogenetic position of Anindobothrium and provide molecular and morphological evidence to recognize two additional species for the genus. The taxonomic actions that followed our analyses included the proposition of a new family, Anindobothriidae fam. n., to accommodate the genus Anindobothrium in the order Rhinebothriidea Healy, Caira, Jensen, Webster & Littlewood, 2009 and the description of two new species-one from the eastern Pacific Ocean, A. carrioni sp. n., and the other from the Caribbean Sea, A. inexpectatum sp. n. In addition, we also present a

  10. A new 10Be chronology of the LGM in the Brooks Range, Arctic Alaska

    Science.gov (United States)

    Ceperley, E. G.; Pendleton, S. L.; Briner, J. P.; Zimmerman, S. R.

    2013-12-01

    Unlike most of the Arctic, Alaska was glaciated by mountain glaciers rather than an ice sheet during the Last Glacial Maximum (LGM). Reconstructing past mountain-glacier fluctuations in the Brooks Range can shed light on past climatic change on both regional and global scales, such as the history of temperature and moisture availability as well as the synchronicity of glaciation throughout the Arctic. The existing LGM chronology in the Brooks Range is based on 14C ages in outwash sequences, which bracket the timing of glacier advance and retreat. Interestingly, the existing chronology suggests that the local LGM occurred ~29-27 ka in the Brooks Range, which is prior to the global LGM (~26-19 ka). We aim to test the outwash radiocarbon chronology by directly dating LGM moraines using cosmogenic 10Be exposure dating. We collected nine samples from large moraine boulders resting on an LGM (locally termed the Itkillik II glaciation) terminal moraine sequence in Alapah Valley in the north-central Brooks Range. In addition, we collected five boulders from a second moraine upvalley associated with Itkillik III glacial phase, thought by previous workers to be Late Glacial in age. The samples from the Itkillik II moraine are awaiting AMS analysis at the time of this writing. The 10Be ages from the Itkillik III moraine average 17.2×1.0 ka. The Itkillik III moraine is 70 km upvalley from Itkillik II moraines, implying considerable retreat between the LGM terminal moraine and the 17 ka moraine. This contrasts with lower latitudes where glaciers remained near their LGM position until ~17 ka or even later. The 10Be ages we have obtained from the Itkillik III moraine correlate with the established glacial record based on radiocarbon-dated outwash deposits. If the existing 14C chronology in outwash is correct, it implies a relatively early local LGM followed by significant glacier recession between ~27 and ~17 ka, during the global LGM. This implies relative warmth or reduced

  11. Systematics and diversification of Anindobothrium Marques, Brooks & Lasso, 2001 (Eucestoda: Rhinebothriidea.

    Directory of Open Access Journals (Sweden)

    Bruna Trevisan

    Full Text Available Tapeworms of the genus Anindobothrium Marques, Brooks & Lasso, 2001 are found in both marine and Neotropical freshwater stingrays of the family Potamotrygonidae. The patterns of host association within the genus support the most recent hypothesis about the history of diversification of potamotrygonids, which suggests that the ancestor of freshwater lineages of the Potamotrygonidae colonized South American river systems through marine incursion events. Despite the relevance of the genus Anindobothrium to understand the history of colonization and diversification of potamotrygonids, no additional efforts were done to better investigate the phylogenetic relationship of this taxon with other lineages of cestodes since its erection. This study is a result of recent collecting efforts to sample members of the genus in marine and freshwater potamotrygonids that enabled the most extensive documentation of the fauna of Anindobothrium parasitizing species of Styracura de Carvalho, Loboda & da Silva, Potamotrygon schroederi Fernández-Yépez, P. orbignyi (Castelnau and P. yepezi Castex & Castello from six different countries, representing the eastern Pacific Ocean, Caribbean Sea, and river basins in South America (Rio Negro, Orinoco, and Maracaibo. The newly collected material provided additional specimens for morphological studies and molecular samples for subsequent phylogenetic analyses that allowed us to address the phylogenetic position of Anindobothrium and provide molecular and morphological evidence to recognize two additional species for the genus. The taxonomic actions that followed our analyses included the proposition of a new family, Anindobothriidae fam. n., to accommodate the genus Anindobothrium in the order Rhinebothriidea Healy, Caira, Jensen, Webster & Littlewood, 2009 and the description of two new species-one from the eastern Pacific Ocean, A. carrioni sp. n., and the other from the Caribbean Sea, A. inexpectatum sp. n. In addition, we

  12. Two stages of deformation and fluid migration in the central Brooks Range fold-and-thrust belt

    Science.gov (United States)

    Moore, Thomas E.; Potter, Christopher J.; O'Sullivan, Paul B.; Shelton, Kevin L.; Underwood, Michael B.

    2004-01-01

    The Brooks Range is a north-directed fold and thrust belt that forms the southern boundary of the North Slope petroleum province in northern Alaska. Field-based studies have long recognized that large-magnitude, thin-skinned folding and thrusting in the Brooks Range occurred during arc-continent collision in the Middle Jurassic to Early Cretaceous (Neocomian). Folds and thrusts, however, also deform middle and Upper Cretaceous strata of the Colville foreland basin and thus record a younger phase of deformation that apatite fission-track data have shown to occur primarily during the early Tertiary (~60 and ~45 Ma). A structural and kinematic model that reconciles these observations is critical to understanding the petroleum system of the Brooks Range fold and thrust belt.

  13. Past and future effects of atmospheric deposition on the forest ecosystem at the Hubbard Brook Experimental Forest: simulations with the dynamic model ForSAFE

    Science.gov (United States)

    Salim Belyazid; Scott Bailey; Harald. Sverdrup

    2010-01-01

    The Hubbard Brook Ecosystem Study presents a unique opportunity for studying long-term ecosystem responses to changes in anthropogenic factors. Following industrialisation and the intensification of agriculture, the Hubbard Brook Experimental Forest (HBEF) has been subject to increased loads of atmospheric deposition, particularly sulfur and nitrogen. The deposition of...

  14. Seasonally dynamic diel vertical migrations of Mysis diluviana, coregonine fishes, and siscowet lake trout in the pelagia of western Lake Superior

    Science.gov (United States)

    Ahrenstorff, Tyler D.; Hrabik, Thomas R.; Stockwell, Jason D.; Yule, Daniel L.; Sass, Greg G.

    2011-01-01

    Diel vertical migrations are common among many aquatic species and are often associated with changing light levels. The underlying mechanisms are generally attributed to optimizing foraging efficiency or growth rates and avoiding predation risk (μ). The objectives of this study were to (1) assess seasonal and interannual changes in vertical migration patterns of three trophic levels in the Lake Superior pelagic food web and (2) examine the mechanisms underlying the observed variability by using models of foraging, growth, and μ. Our results suggest that the opossum shrimp Mysis diluviana, kiyi Coregonus kiyi, and siscowet lake trout Salvelinus namaycush migrate concurrently during each season, but spring migrations are less extensive than summer and fall migrations. In comparison with M. diluviana, kiyis, and siscowets, the migrations by ciscoes C. artedi were not as deep in the water column during the day, regardless of season. Foraging potential and μ probably drive the movement patterns of M. diluviana, while our modeling results indicate that movements by kiyis and ciscoes are related to foraging opportunity and growth potential and receive a lesser influence from μ. The siscowet is an abundant apex predator in the pelagia of Lake Superior and probably undertakes vertical migrations in the water column to optimize foraging efficiency and growth. The concurrent vertical movement patterns of most species are likely to facilitate nutrient transport in this exceedingly oligotrophic ecosystem, and they demonstrate strong linkages between predators and prey. Fishery management strategies should use an ecosystem approach and should consider how altering the densities of long-lived top predators produces cascading effects on the nutrient cycling and energy flow in lower trophic levels.

  15. 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

  16. Habitat suitability index models: Cutthroat trout

    Science.gov (United States)

    Hickman, Terry J.; Raleigh, Robert F.

    1982-01-01

    Cutthroat trout, Salmo clarki, are a polytypic species consisting of several geographically distinct forms with a broad distribution and a great amount of genetic diversity (Hickman 1978; Behnke 1979). Behnke (1979) recognized 13 extant subspecies: Coastal cutthroat (S. c. clarki) in coastal streams from Prince William Sound, Alaska to the Eel Rlver in California; mountain cutthroat (~. ~. alpestris) in upper Columbia and F~Dser River drainages of British Columbia; west slope cutthroat (S. c. lewisi) in the upper Columbia, Salmon, Clearwater, South Saskatchewan and upper Missouri drainages of Montana and Idaho; an undescribed subspecies in the Alvord basin, Oregon; Lahonton cutthroat (S. c ..henshawi), Pauite cutthroat (S. c. seleniris), and an undescribed- subspecies in the Humboldt River drafnage of the Lahontan basin of Nevada and California; Yellowstone cutthroat (S. c. bouvieri) in the Yellowstone drainage of Wyoming and Montana and the Snake River drainage of Wyoming, Idaho, and Nevada; an undescribed subspecies (fine spotted) in the upper Snake River, Wyoming; Bonneville cutthroat (S. c. utah) in the Bonneville basin in Utah, Nevada, Idaho, and Wyoming; Colorado River cutthroat (~. ~. pleuriticus) in the Colorado River drainage in Wyoming, Utah, New Mexico, and Colorado; greenback cutthroat (S. c. stomias) in the South Platte and Arkansas River systems; and Rio Grande cutthroat (~. ~. virginalis) in the Rio Grande River drainage of Colorado and New Mexico. Many of these 13 subspecies are included on Federal or State endangered or threatened species lists.Temperature and chemical preferences, migration, and other ecological and life history attributes vary among cutthroat subspecies (Behnke 1979). Differences in growth rate (Carlander 1969; Scott and Crossman 1973; Behnke 1979) and food preferences have also been reported (Trojnar and Behnke 1974) between some subspecies.

  17. BIOMASS AND DENSITY OF BROWN AND RAINBOW TROUT IN NEW MEXICO STREAMS

    Directory of Open Access Journals (Sweden)

    Srečko Lainer

    1995-03-01

    Full Text Available Mean stream numerical density of the brown trout (Salmo trutta m. fario Linnaeus, 1758 and the rainbow trout (Onchorhynchus mykiss Walbaum, 1792 was 0.090 fish/m2 of which brown trout averaged 69% (72% in total biomass in 15 high-elevation New Mexico streams (1,661-2,560 m above sea level. Total trout density varied from 0.008/m2 in 1988 and 1989. Mean trout density ranged between 0.023-0.121 fish/m2 at site s open to public fishing. Considerably higher densities (0.142-0.409 fish/m2 were observed at sites closed for fishing. In the seven selected streams shared by both species, brown trout density exceeded rainbow trout density except at the two sites closed to fishing. Brown trout were stocked only as fingerlings (average 7,000 fish/stream/year while rainbow trout were stocked only in harvestable sizes (11,000 fish/stream/year. Reported total trout yield rates exceeded the total number of fish estimated to be in the stream by 1.01 to 11.63 in most small streams open to fishing. The proportional stock density (PSD ranged between O and 50 percent. Streams with low to moderate intensities of fishing had the highest PSD.

  18. Interspecific interactions between brown trout and slimy sculpin in stream enclosures

    Science.gov (United States)

    Ruetz, C. R.; Hurford, A.L.; Vondracek, B.

    2003-01-01

    We conducted a 30-d manipulative experiment in Valley Creek, Minnesota, to examine interspecific interactions between juvenile brown trout Salmo trutta and adult slimy sculpin Cottus cognatus. We measured the instantaneous growth of each species in the presence and absence of the other in 1-m2 enclosures. We tested single-species (three slimy sculpins/m2 or three brown trout/m2) and combined-species (three sculpins/m2 and three trout/m2) combinations in each of six riffles. We placed a clay tile in each enclosure to evaluate the effects of fish combinations on benthic macroinvertebrates. Growth of brown trout was unaffected by the presence of slimy sculpins (P = 0.647, power [to detect 50% increase in growth] = 0.92), whereas slimy sculpin growth was less in the presence of brown trout (P = 0.038). Densities of total benthic macroinvertebrates, Chironomidae, Trichoptera, and Physa did not differ among fish combinations (P > 0.3). However, densities of Gammarus pseudolimnaeus were significantly less in the presence of brown trout irrespective of the presence of slimy sculpins (P = 0.024), which could be a causal factor underlying the interaction between brown trout and slimy sculpins. We found asymmetrical competition between brown trout and slimy sculpins in stream enclosures, with brown trout being the superior competitor. Nevertheless, the size of enclosures may have biased our results, making it more likely to detect an effect of brown trout on slimy sculpins than vice versa.

  19. Conservation of native Pacific trout diversity in Western North America

    Science.gov (United States)

    Brooke E. Penaluna; Alicia Abadía-Cardoso; Jason B. Dunham; Francisco J. García-Dé León; Robert E. Gresswell; Arturo Ruiz Luna; Eric B. Taylor; Bradley B. Shepard; Robert Al-Chokhachy; Clint C. Muhlfeld; Kevin R. Bestgen; Kevin Rogers; Marco A. Escalante; Ernest R. Keeley; Gabriel M. Temple; Jack E. Williams; Kathleen R. Matthews; Ron Pierce; Richard L. Mayden; Ryan P. Kovach; John Carlos Garza; Kurt D. Fausch

    2016-01-01

    Pacific trout Oncorhynchus spp. in western North America are strongly valued in ecological, socioeconomic, and cultural views, and have been the subject of substantial research and conservation efforts. Despite this, the understanding of their evolutionary histories, overall diversity, and challenges to their conservation is incomplete. We review...

  20. Lake Michigan lake trout PCB model forecast post audit

    Science.gov (United States)

    Scenario forecasts for total PCBs in Lake Michigan (LM) lake trout were conducted using the linked LM2-Toxics and LM Food Chain models, supported by a suite of additional LM models. Efforts were conducted under the Lake Michigan Mass Balance Study and the post audit represents th...

  1. Influence of waterfalls on patterns of association between trout and ...

    African Journals Online (AJOL)

    Current literature suggests that little, if any, research has been conducted in South Africa to determine the impact of alien trout on indigenous amphibian biodiversity. The aim of this study was to establish whether waterfalls in the uKhahlamba Drakensberg Park, South Africa, are seasonally important in conserving ...

  2. Estrogenic response of bisphenol A in rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Lindholst, Christian; Pedersen, Knud Ladegaard; Pedersen, Søren Nørby

    2000-01-01

    Bisphenol A (BPA) previously shown to possess xenoestrogenic activities was administered to rainbow trout (Oncorhynchus mykiss) through a continuos flow system. The estrogenic response expressed as the induction of vitellogenin (VTG) synthesis was measured during 12 days of exposure, using a direct...

  3. Rainbow trout offspring with different resistance to viral haemorrhagic septicaemia

    DEFF Research Database (Denmark)

    Slierendrecht, W.J.; Olesen, Niels Jørgen; Juul-Madsen, H.R.

    2001-01-01

    To study immunological and immunogenetical parameters related to resistance against viral haemorrhagic septicaemia (VHS), attempts to make gynogenetic strains of rainbow trout selected for high and low resistance to VHS were initiated in 1988. The first gynogenetic generation of inbreeding resulted...

  4. Studies on the motility and cryopreservation of rainbow trout

    African Journals Online (AJOL)

    Studies on the motility and cryopreservation of rainbow trout (Salmo gairdnerl) spermatozoa. G. van der Horst, H.M. Dott and G.C. Foster. ARC, Institute of Animal Physiology, Animal Research Station, Cambridge, United Kingdom. The very short duration of vigorous movement (1'12 to 7 min) in fresh water and physiological ...

  5. Feeding ecology of Brook Silverside, Golden Shiner, and Subyearling Pumpkinseed in a Lake Ontario embayment

    Science.gov (United States)

    Johnson, James H.; Chalupnicki, Marc; Abbett, Ross; Diaz, Avriel R; Nack, Christopher C

    2017-01-01

    Fish feeding ecology has been shown to vary over a 24-h period in terms of the prey consumed and feeding intensity. Consequently, in order to best determine the interspecific feeding associations within a fish community, examination of the diet at multiple times over a 24-h period is often necessary. We examined the diel feeding ecology of three fish species that were numerically dominant in a Lake Ontario embayment during summer. The diet of each of the three species, young-of-year Pumpkinseed Lepomis gibbosus, Golden Shiner Notemigonus crysoleucas, and Brook Silverside Labidesthes sicculus, was distinct with no significant overlap in diet composition occurring within any of the 4-h time intervals. The diet composition of each species suggested that Brook Silverside were feeding at the surface (terrestrial invertebrates and aquatic surface dwelling hemipterans), whereas young-of-year Pumpkinseed (amphipods) and Golden Shiner (tipulids) were feeding on different benthic prey. Differences in feeding periodicity were most pronounced for young-of-year Pumpkinseed. Our findings provide valuable insights on interspecific feeding associations among these three fish species during summer in a Lake Ontario embayment.

  6. Northeastern Brooks Range, Alaska: new evidence for complex thin-skinned thrusting

    Energy Technology Data Exchange (ETDEWEB)

    Rattey, R.P.

    1985-04-01

    Extensive fieldwork has shed new light on the style of deformation in the Franklin, Ramanzof, and British Mountains of the northeastern Brooks Range. Bedding-parallel thrusting controls the structure, and two major decollements are recognized. In the mountain belt, the lower one lies in the Lower Carboniferous Kayak Formation but often steps down to the base of the Upper Devonian Kanayut or Lower Carboniferous Kekiktuk Conglomerates. Near the Sadlerochit and Shublik Mountains, it steps down to its deepest level to the base of the Cambrian to Middle Devonian Katakturuk Dolomite. The upper decollement is poorly exposed in the mountains and lies in the Jurassic Kingak Shale. Locally, these are removed by Early Cretaceous erosion and the decollement steps unsequence. The two decollements separate three tectonic sequences that deform differently. First, basement below the lower decollement deforms into a set of thrust duplexes. The core of these is well exposed in the Franklin Mountains. The Sagavanirktok sidewall ramp is a major basement structure that causes the northern swing in the mountain front between the central and northeastern Brooks Range. Second, the lower cover between the two decollements deforms more complexly than basement by both passive drape over the underlying duplexes and by active thrust stacking. Large-scale buckle folding occurs in a shear zone above the Sagavanirktok sidewall ramp. Third, the upper cover above the upper decollement is poorly preserved in the mountains as allochthonous klippe in depressions in the basement and lower cover duplexes.

  7. Structural provinces of the northeastern Brooks Range, Arctic National Wildlife Refuge, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, W.K.; Hanks, C.L. (Univ. of Alaska, Fairbanks (USA))

    1990-07-01

    The dominant Cenozoic structures of the northeastern Brooks Range are anticlinoria with cores of sub-Mississippian rocks, reflecting a regional north-vergent duplex with a floor thrust in the sub-Mississippian sequence and a roof thrust in the Mississippian Kayak Shale. The number of horses forming each anticlinorium and the structural style of the overlying Mississippian and younger cover sequence varies regionally, providing a basis for dividing the northeastern Brooks Range into structural provinces. In the western province, each anticlinorium contains a single horse, and shortening above the Kayak Shale was accommodated mainly by detachment folds. To the north in the Sadlerochit Mountains, the Kayak Shale is depositionally discontinuous and rocks elsewhere separated by this detachment deformed together. In the eastern province, each anticlinorium contains multiple horses, and shortening above the Kayak Shale was accommodated largely by thrust duplication of Mississippian through Triassic rocks. In the narrow central province, the Devonian Okpilak batholith was detached from its roots, internally shortened along shear zones and by penetrative strain, and transported northward. Because the Kayak Shale is locally absent, the Mississippian and younger cover sequence deformed in part penetratively along with the batholith. 13 figs.

  8. NASA's Hydrogen Outpost: The Rocket Systems Area at Plum Brook Station

    Science.gov (United States)

    Arrighi, Robert S.

    2016-01-01

    "There was pretty much a general knowledge about hydrogen and its capabilities," recalled former researcher Robert Graham. "The question was, could you use it in a rocket engine? Do we have the technology to handle it? How will it cool? Will it produce so much heat release that we can't cool the engine? These were the questions that we had to address." The National Aeronautics and Space Administration's (NASA) Glenn Research Center, referred to historically as the Lewis Research Center, made a concerted effort to answer these and related questions in the 1950s and 1960s. The center played a critical role transforming hydrogen's theoretical potential into a flight-ready propellant. Since then NASA has utilized liquid hydrogen to send humans and robots to the Moon, propel dozens of spacecraft across the universe, orbit scores of satellite systems, and power 135 space shuttle flights. Rocket pioneers had recognized hydrogen's potential early on, but its extremely low boiling temperature and low density made it impracticable as a fuel. The Lewis laboratory first demonstrated that liquid hydrogen could be safely utilized in rocket and aircraft propulsion systems, then perfected techniques to store, pump, and cleanly burn the fuel, as well as use it to cool the engine. The Rocket Systems Area at Lewis's remote testing area, Plum Brook Station, played a little known, but important role in the center's hydrogen research efforts. This publication focuses on the activities at the Rocket Systems Area, but it also discusses hydrogen's role in NASA's space program and Lewis's overall hydrogen work. The Rocket Systems Area included nine physically modest test sites and three test stands dedicated to liquid-hydrogen-related research. In 1962 Cleveland Plain Dealer reporter Karl Abram claimed, "The rocket facility looks more like a petroleum refinery. Its test rigs sprout pipes, valves and tanks. During the night test runs, excess hydrogen is burned from special stacks in the best

  9. Sanctuaries for lake trout in the Great Lakes

    Science.gov (United States)

    Stanley, Jon G.; Eshenroder, Randy L.; Hartman, Wilbur L.

    1987-01-01

    Populations of lake trout, severely depleted in Lake Superior and virtually extirpated from the other Great Lakes because of sea lamprey predation and intense fishing, are now maintained by annual plantings of hatchery-reared fish in Lakes Michigan, Huron, and Ontario and parts of Lake Superior. The extensive coastal areas of the Great Lakes and proximity to large populations resulted in fishing pressure on planted lake trout heavy enough to push annual mortality associated with sport and commercial fisheries well above the critical level needed to reestablish self-sustaining stocks. The interagency, international program for rehabilitating lake trout includes controlling sea lamprey abundance, stocking hatchery-reared lake trout, managing the catch, and establishing sanctuaries where harvest is prohibited. Three lake trout sanctuaries have been established in Lake Michigan: the Fox Island Sanctuary of 121, 500 ha, in the Chippewa-Ottawa Treaty fishing zone in the northern region of the lake; the Milwaukee Reef Sanctuary of 160, 000 ha in midlake, in boundary waters of Michigan and Wisconsin; and Julian's Reef Sanctuary of 6, 500 ha, in Illinois waters. In northern Lake Huron, Drummond Island Sanctuary of 55, 000 ha is two thirds in Indian treaty-ceded waters in Michigan and one third in Ontario waters of Canada. A second sanctuary, Six Fathom Bank-Yankee Reef Sanctuary, in central Lake Huron contains 168, 000 ha. Sanctuary status for the Canadian areas remains to be approved by the Provincial government. In Lake Superior, sanctuaries protect the spawning grounds of Gull Island Shoal (70, 000 ha) and Devils Island Shoal (44, 000 ha) in Wisconsin's Apostle Island area. These seven sanctuaries, established by the several States and agreed upon by the States, Indian tribes, the U.S. Department of the Interior, and the Province of Ontario, contribute toward solving an interjurisdictional fishery problem.

  10. Microsatellite and mitochondrial DNA polymorphism reveals life history dependent interbreeding between hatchery and wild brown trout ( Salmo trutta L.)

    DEFF Research Database (Denmark)

    Hansen, Michael Møller; Ruzzante, D.E.; Eg Nielsen, Einar

    2000-01-01

    The effects of stocking hatchery trout into wild populations were studied in a Danish river, using microsatellite and mitochondrial DNA (mtDNA) markers. Baseline samples were taken from hatchery trout and wild trout assumed to be unaffected by previous stocking. Also, samples were taken from...... resident and sea trout from a stocked section of the river. Genetic differentiation between the hatchery strain and the local wild population was modest (microsatellite F-ST = 0.06). Using assignment tests, more than 90% of individuals from the baseline samples were classified correctly. Assignment tests...... involving samples from the stocked river section suggested that the contribution by hatchery trout was low among sea trout (

  11. Occurrence and effects of the parasitic copepod Salmincola carpionis on salmonids in the Nikko District, central Japan

    Science.gov (United States)

    Nagasawa, Kazuya; Ikuta, Kazumasa; Nakamura, Hidefumi; Shikama, Toshio; Kitamura, Shoji

    1998-06-01

    Salmincola carpionis (Krøyer, 1837) occurred on brook trout ( Salvelinus fontinalis) and whitespotted charr ( Salvelinus leucomaenis) reared at a fisheries research institute in the Nikko District, central Japan, and also on a wild population of the latter species that had returned for spawning from a lake to streams near the institute. Its infection levels on these salmonids were associated with age and size of fish and the location of rearing ponds, older (larger) fish reared in the lower-located ponds being more frequently and heavily infected than smaller (younger) fish from the upper-located ponds. Swellings were observed at sites where the bulla of S. carpionis was deeply implanted. The condition factor of heavily infected (>50 copepods) fish was lower than those of lightly infected fish (1-18 copepods). Salmincola carpionis did not occur on lake trout ( Salvelinus namaycush) which belong to the subgenus Cristivomer, as well as on salmonids of the genera Oncorhynchus and Salmo, possibly due strict host specificity.

  12. A mathematical model of predator-prey interaction between seal-herring and steelhead trout

    Science.gov (United States)

    Triharyuni, S.; Aldila, D.

    2017-07-01

    A mathematical model of predator-prey interaction between Seal, Herring and Steelhead Trout will be introduced in this article. The population of Steelhead Trout is divided into two subpopulations according to their living ecosystem, i.e in freshwater and sea ecosystem. Therefore, the model will be developed as a four-dimensional system of differential equation. The migration of Steelhead Trout is assumed to take place all over the year as a constant parameter as well as the harvesting rate in Herring and Steelhead Trout population. Mathematical analysis of the equilibrium points and local stability criteria was done. Some numerical simulation to give an interpretation about the analytical results has been conducted. The result shown that harvesting steelhead trout in fresh water has a significant impact to the ecosystem. Having the periodic harvesting strategy on the steelhead trout allows the population to recover and to ensure the sustainable harvest.

  13. Media Literacy, News Literacy, or News Appreciation? A Case Study of the News Literacy Program at Stony Brook University

    Science.gov (United States)

    Fleming, Jennifer

    2014-01-01

    This case study provides practical and theoretical insights into the Stony Brook news literacy program, which is one of the most ambitious and well-funded curricular experiments in modern journalism education and media literacy. Analysis of document, interview, and observation data indicates that news literacy educators sought to teach students…

  14. On Conceptual Metaphor and the Flora and Fauna of Mind: Commentary on Brookes and Etkina; and Jeppsson, Haglund, and Amin

    Science.gov (United States)

    Sherin, Bruce

    2015-01-01

    In this commentary, the author presents his thoughts on two papers appearing in this special issue. The first, "The Importance of Language in Students' Reasoning about Heat in Thermodynamic Processes," by David T. Brookes and Eugenia Etkina (See: EJ1060728), and the second, "Varying Use of Conceptual Metaphors Across Levels of…

  15. A Comparison of Some Aspects of Two Extinct Mammals, Mammuthus Brookes, 1828 (Proboscidea: Elephantidae) and Mammut Blumenbach, 1799 (Proboscidea: Mammutidae)

    OpenAIRE

    Pankaj S. Bhatnagar

    2013-01-01

    The present study aims at extracting the fossil database www.paleodb.org to compare extinct megafauna genera, Mammuthus Brookes, 1828 and Mammut Blumenbach, 1799 along with its close reletive, Zygolophodon (Vacek, 1877). Taxon count indicated 9 species for the former genus, and a dozen species for the latter two genera taken together. Mammuthus scored higher than Mammut and Zygolophodon in occurrences. ...

  16. Enrichment Programs and Professional Development in the Geosciences: Best Practices and Models (OEDG Research Report, Stony Brook University)

    Science.gov (United States)

    Gafney, Leo

    2017-01-01

    This report is based on several evaluations of NSF-funded geoscience projects at Stony Brook University on Long Island, NY. The report reviews the status of K-12 geoscience education, identifying challenges posed by the Next Generation Science Standards (NGSS), the experiences of university faculty engaged in teacher preparation, state…

  17. Variation in chemistry of stream water and bulk deposition across the Hubbard Brook Valley, New Hampshire, USA

    Science.gov (United States)

    Gene E. Likens; Donald C. Buso; James W. Hornbeck

    2002-01-01

    Chemistry and volume of precipitation and stream water have been measured in south-facing watersheds of the Hubbard Brook Experimental Forest (HBEF), continuously for 37 years. These long-term data have provided important insights into the bio-geochemistry of these watershed ecosystems and the region (e.g. LIKENS & BORMANN 1995).

  18. What Do Facts Have to Do with It? Exploring Instructional Emphasis in Stony Brook News Literacy Curriculum

    Science.gov (United States)

    Fleming, Jennifer

    2015-01-01

    An analytic matrix comprised of multiple media literacy teaching and learning principles is conceptualized to examine a model of news literacy developed by journalism educators at Stony Brook University. The multidimensional analysis indicates that news literacy instructors focus on teaching students how to question and assess the veracity of news…

  19. Potential population and assemblage influences of non-native trout on native nongame fish in Nebraska headwater streams

    Science.gov (United States)

    Turek, Kelly C.; Pegg, Mark A.; Pope, Kevin L.; Schainost, Steve

    2014-01-01

    Non-native trout are currently stocked to support recreational fisheries in headwater streams throughout Nebraska. The influence of non-native trout introductions on native fish populations and their role in structuring fish assemblages in these systems is unknown. The objectives of this study were to determine (i) if the size structure or relative abundance of native fish differs in the presence and absence of non-native trout, (ii) if native fish-assemblage structure differs in the presence and absence of non-native trout and (iii) if native fish-assemblage structure differs across a gradient in abundances of non-native trout. Longnose dace Rhinichthys cataractae were larger in the presence of brown trout Salmo trutta and smaller in the presence of rainbow trout Oncorhynchus mykiss compared to sites without trout. There was also a greater proportion of larger white suckers Catostomus commersonii in the presence of brown trout. Creek chub Semotilus atromaculatus and fathead minnow Pimephales promelas size structures were similar in the presence and absence of trout. Relative abundances of longnose dace, white sucker, creek chub and fathead minnow were similar in the presence and absence of trout, but there was greater distinction in native fish-assemblage structure between sites with trout compared to sites without trout as trout abundances increased. These results suggest increased risk to native fish assemblages in sites with high abundances of trout. However, more research is needed to determine the role of non-native trout in structuring native fish assemblages in streams, and the mechanisms through which introduced trout may influence native fish populations.

  20. Quality effect of freeze-chilling in cod and rainbow trout

    DEFF Research Database (Denmark)

    Jensen, Louise Helene Søgaard; Nielsen, Jette; Jørgensen, Bo

    are known to differ among fish species, the present study included the popular species cod (Gadus Morhua) and rainbow trout (Oncorhynchus Mykiss). Principal component analysis of the sensory results clearly showed that after frozen storage at -30 °C for 1 month and subsequent chill storage at +2 °C, trout...... is practically applicable and cod and rainbow trout seem potential candidates for freeze-chilled meal elements....

  1. A single rainbow trout cobalamin-binding protein stands in for three human binders

    DEFF Research Database (Denmark)

    Greibe, Eva; Fedosov, Sergey; Sorensen, Boe S

    2012-01-01

    -binding proteins of the rainbow trout (Oncorhynchus mykiss) and to compare their properties with those of the three human cobalamin-binding proteins. High cobalamin-binding capacity was found in trout stomach (210 pmol/g), roe (400 pmol/g), roe fluid (390 nmol/liter), and plasma (2500 nmol/liter). In all cases...... affinity for the cobalamin analog cobinamide. Like haptocorrin and transcobalamin, the trout cobalamin-binding protein was present in plasma and recognized ligands with altered nucleotide moiety. Like intrinsic factors, the trout cobalamin-binding protein was present in the stomach and resisted degradation...

  2. Identifying footprints of selection in stocked brown trout populations: a spatio-temporal approach

    DEFF Research Database (Denmark)

    Hansen, Michael Møller; Meier, Kristian; Mensberg, Karen-Lise Dons

    2010-01-01

    Studies of interactions between farmed and wild salmonid fishes have suggested reduced fitness of farmed strains in the wild, but evidence for selection at the genic level is lacking. We studied three brown trout populations in Denmark which have been significantly admixed with stocked hatchery...... trout. In the most strongly admixed population, however, there was no evidence for selection, possibly because of immigration by stocked trout overcoming selection against hatchery-derived alleles or supportive breeding practices allowing hatchery strain trout to escape natural selection. To our...

  3. Influence of Didymosphenia geminata blooms on prey composition and associated diet and growth of Brown Trout

    Science.gov (United States)

    James, Daniel A.; Chipps, Steven R.

    2016-01-01

    We compared diet, stomach fullness, condition, and growth of Brown Trout Salmo trutta among streams with or without blooms of the benthic diatom Didymosphenia geminata in the Black Hills, South Dakota. In Rapid Creek, where D. geminata blooms covered ∼30% of the stream bottom, Brown Trout consumed fewer ephemeropterans (6–8% by weight) than individuals from two stream sections that have not had D. geminatablooms (Castle and Spearfish creeks; 13–39% by weight). In contrast, dipterans (primarily Chironomidae) represented a larger percentage of Brown Trout diets from Rapid Creek (D. geminata blooms present; 16–28% dry weight) compared with diets of trout from streams without D. geminata blooms (6–19% dry weight). Diets of small Brown Trout (100–199 mm TL) reflected the invertebrate species composition in benthic stream samples; in Rapid Creek, ephemeropterans were less abundant whereas dipterans were more abundant than in streams without D. geminata blooms. Stomach fullness and condition of Brown Trout from Rapid Creek were generally greater than those of Brown Trout from other populations. Linkages among invertebrate availability, diet composition, and condition of Brown Trout support the hypothesis that changes in invertebrate assemblages associated with D. geminata (i.e., more Chironomidae) could be contributing to high recruitment success for small Brown Trout in Rapid Creek.

  4. Deformation and the timing of gas generation and migration in the eastern Brooks Range foothills, Arctic National Wildlife Refuge, Alaska

    Science.gov (United States)

    Parris, T.M.; Burruss, R.C.; O'Sullivan, P. B.

    2003-01-01

    Along the southeast border of the 1002 Assessment Area in the Arctic National Wildlife Refuge, Alaska, an explicit link between gas generation and deformation in the Brooks Range fold and thrust belt is provided through petrographic, fluid inclusion, and stable isotope analyses of fracture cements integrated with zircon fission-track data. Predominantly quartz-cemented fractures, collected from thrusted Triassic and Jurassic rocks, contain crack-seal textures, healed microcracks, and curved crystals and fluid inclusion populations, which suggest that cement growth occurred before, during, and after deformation. Fluid inclusion homogenization temperatures (175-250??C) and temperature trends in fracture samples suggest that cements grew at 7-10 km depth during the transition from burial to uplift and during early uplift. CH4-rich (dry gas) inclusions in the Shublik Formation and Kingak Shale are consistent with inclusion entrapment at high thermal maturity for these source rocks. Pressure modeling of these CH4-rich inclusions suggests that pore fluids were overpressured during fracture cementation. Zircon fission-track data in the area record postdeposition denudation associated with early Brooks Range deformation at 64 ?? 3 Ma. With a closure temperature of 225-240??C, the zircon fission-track data overlap homogenization temperatures of coeval aqueous inclusions and inclusions containing dry gas in Kingak and Shublik fracture cements. This critical time-temperature relationship suggests that fracture cementation occurred during early Brooks Range deformation. Dry gas inclusions suggest that Shublik and Kingak source rocks had exceeded peak oil and gas generation temperatures at the time structural traps formed during early Brooks Range deformation. The timing of hydrocarbon generation with respect to deformation therefore represents an important exploration risk for gas exploration in this part of the Brooks Range fold and thrust belt. The persistence of gas high at

  5. The Impact of Climate Change on Past and Future Streamflow at the Hubbard Brook Experimental Forest, New Hampshire, USA

    Science.gov (United States)

    Campbell, J. L.; Driscoll, C. T.; Pourmokhtarian, A.

    2009-12-01

    Long-term data from the Hubbard Brook Experimental Forest show that air temperature has increased by 1-1.5 °C over the last half century. While more variable, annual precipitation has also increased by 19-26% during the same period. These changes in climate influence streamflow, which provides an integrated climate signal that incorporates physical (snowpack, evaporation) and biological (evapotranspiration) responses. Unlike the western United States, water is generally abundant in the Northeast. However, changes in flow could nevertheless affect stream ecosystem services in the region, such as drinking water, irrigation, recreation, wastewater assimilation, and hydropower. We analyzed long-term data at the Hubbard Brook Experimental Forest to determine if past changes in climate have affected the distribution and quantity of streamflow. We also analyzed future changes in streamflow using the forest ecosystem model, PnET-BGC driven by climate input scenarios generated using downscaled AOGCM output. Past streamflow data indicate that the timing of streamflow has changed at Hubbard Brook. The winter/spring center of streamwater volume is occurring 0.18-0.25 days earlier each year, and streamflow increases during snowmelt have become less extreme over the 50 year record. Despite declines in snowmelt runoff, the number of high flow days per year has increased, due to increases in precipitation. Similarly, greater precipitation amounts have resulted in fewer low flow days. The overall amount of annual streamflow has increased significantly over the last 50 years, consistent with an increase in precipitation and no change in evapotranspiration. Future climate projections for Hubbard Brook show that air temperature and precipitation will continue to increase during the 21st century. Unlike historical data, preliminary PnET-BGC results indicate that projected increases in evapotranspiration will balance increases in precipitation, resulting in no significant change in

  6. Temporary Restoration of Bull Trout Passage at Albeni Falls Dam

    Energy Technology Data Exchange (ETDEWEB)

    Paluch, Mark; Scholz, Allan; McLellan, Holly [Eastern Washington University Department of Biology; Olson, Jason [Kalispel Tribe of Indians Natural Resources Department

    2009-07-13

    This study was designed to monitor movements of bull trout that were provided passage above Albeni Falls Dam, Pend Oreille River. Electrofishing and angling were used to collect bull trout below the dam. Tissue samples were collected from each bull trout and sent to the U. S. Fish and Wildlife Service Abernathy Fish Technology Center Conservation Genetics Lab, Washington. The DNA extracted from tissue samples were compared to a catalog of bull trout population DNA from the Priest River drainage, Lake Pend Oreille tributaries, and the Clark Fork drainage to determine the most probable tributary of origin. A combined acoustic radio or radio tag was implanted in each fish prior to being transported and released above the dam. Bull trout relocated above the dam were able to volitionally migrate into their natal tributary, drop back downstream, or migrate upstream to the next dam. A combination of stationary radio receiving stations and tracking via aircraft, boat, and vehicle were used to monitor the movement of tagged fish to determine if the spawning tributary it selected matched the tributary assigned from the genetic analysis. Seven bull trout were captured during electrofishing surveys in 2008. Of these seven, four were tagged and relocated above the dam. Two were tagged and left below the dam as part of a study monitoring movements below the dam. One was immature and too small at the time of capture to implant a tracking tag. All four fish released above the dam passed by stationary receivers stations leading into Lake Pend Oreille and no fish dropped back below the dam. One of the radio tags was recovered in the tributary corresponding with the results of the genetic test. Another fish was located in the vicinity of its assigned tributary, which was impassable due to low water discharge at its mouth. Two fish have not been located since entering the lake. Of these fish, one was immature and not expected to enter its natal tributary in the fall of 2008. The other

  7. 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]).

  8. Status of rainbow trout in tributaries of the upper King Salmon River, Becharof National Wildlife Refuge, Alaska, 1990-92

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Rainbow trout were monitored in Gertrude Creek and four other tributaries using hook and line during May-September 1990-1991 and May-June 1992. Rainbow trout were...

  9. Rainbow trout estrogen receptor (ER) competitive bindng and vitellogenin induction agonism/antagonism data for 94 chemicals

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset is from screening 94 diverse chemicals for estrogen receptor (ER) activation in a competitive rainbow trout ER binding assay and a trout liver slice...

  10. Incidence of pigmented skin tumors in a population of wild Montseny brook newt (Calotriton arnoldi).

    Science.gov (United States)

    Martínez-Silvestre, Albert; Amat, Fèlix; Bargalló, Ferran; Carranza, Salvador

    2011-04-01

    We report the presence of pigmented skin tumors in three populations of the endangered amphibian Montseny brook newt, Calotriton arnoldi, one of the European amphibian species with the smallest distribution range (40 km(2) in the Montseny Natural Park, Catalonia, Spain). Examination of one of the tumors by light microscopy was consistent with chromatophoroma and was most suggestive of a melanophoroma. Tumors were not found in juveniles. In adults, only two of three populations were affected. The proportions of males and females affected were not significantly different, but there was a positive correlation between body size and presence of tumors in both sexes. The etiology of chromatophoromas remains unknown but, in our study, they do not appear to have been caused by water quality or Ultraviolet B.

  11. Effects of coal pile leachate on Taylor Brook in western Massachusetts

    Energy Technology Data Exchange (ETDEWEB)

    Tan, B.; Coler, R.A.

    1986-01-01

    The metals in Taylor Brook, a second-order stream that receives the runoff and leachate from a coal pile, were analyzed and evaluated for toxicity. Al, Fe and Mn levels were highest immediately downstream from the coal pile at site 4, where the pH was 4.9. The water at this site was soft (41 ppm). Ca and Mg were predominantly unbound, yet maximum binding with organic acids occurred. The increase in SO/sub 4/ concentrations (fourfold) and HCO/sub 3/:SO/sub 4/ ratios indicated little or no buffer capacity but the SO/sub 4/:NO/sub 3/:Cl ratios showed that the effect was local rather than a consequence of acid precipitation alone. The 96-h LC50 values for guppies in water from sites 4 and 3 were 26 and 100%, respectively. The increase of Al (80-fold) was inversely proportional to pH, but this proportionality was more pronounced at site 4 than at site 3. The 36-h LC50 values obtained on the addition of Al and acidity to water from site 3 at the levels measured in water from site 4 were 24% and greater than 100%, respectively. When compared with the values (17% and 49%) derived for site 4 water, the data indicate that the toxicity was principally exerted by aluminium. Residual oxygen data also suggest that fish mortality was primarily a function of Al. Additions of Al (0.3 ppm) to Taylor Brook control site water resulted in increased toxicity to guppies, while added acidity (pH 4.5) has no marked effect. 18 references.

  12. Assessing the potential for rainbow trout reproduction in tributaries of the Mountain Fork River below Broken Bow Dam, southeastern Oklahoma

    Science.gov (United States)

    Long, James M.; Starks, Trevor A.; Farling, Tyler; Bastarache, Robert

    2016-01-01

    Stocked trout (Salmonidae) in reservoir tailwater systems in the Southern United States have been shown to use tributary streams for spawning and rearing. The lower Mountain Fork of the Little River below Broken Bow Dam is one of two year-round tailwater trout fisheries in Oklahoma, and the only one with evidence of reproduction by stocked rainbow trout (Oncorhynchus mykiss). Whether stocked trout use tributaries in this system for spawning is unknown. Furthermore, an

  13. Oxidative stress and partial migration in brown trout (Salmo trutta)

    DEFF Research Database (Denmark)

    Birnie-Gauvin, Kim; Peiman, K. S.; Larsen, Martin Hage

    2017-01-01

    During migration, animals are typically limited by their endogenous energetic resources which must be allocated to the physiological costs associated with locomotion, as well as avoiding and/or compensating for oxidative stress. To date, there have been few attempts to understand the role...... oxidative stress and migration. Using the brown trout, we obtained blood samples from juveniles from a coastal stream in Denmark in the fall prior to peak seaward migration which occurs in the spring, and assayed for antioxidant capacity (oxygen radical absorbance capacity) and oxidative stress levels...... of oxidative status in migration biology, particularly in fish. Semi-anadromous brown trout (Salmo trutta, Linnaeus 1758) exhibit partial migration, where some individuals smoltify and migrate to sea, and others become stream residents, providing us with an excellent model to investigate the link between...

  14. Testing experimental subunit furunculosis vaccines for rainbow trout

    DEFF Research Database (Denmark)

    Marana, Moonika H.; Chettri, Jiwan Kumar; Skov, Jakob

    2016-01-01

    Aeromonas salmonicida subsp. salmonicida (AS) is the etiological agent of typical furunculosis in salmonid fish. The disease causes bacterial septicemia and is a major fish health problem in salmonid aquaculture worldwide, inducing high morbidity and mortality. In this study we vaccinated rainbow...... trout with subunit vaccines containing protein antigens that were selected based on an in silico antigen discovery approach. Thus, the proteome of AS strain A449 was analyzed by an antigen discovery platform and its proteins consequently ranked by their predicted ability to evoke protective immune...... response against AS. Fourteen proteins were prepared in 3 different experimental subunit vaccine combinations and used to vaccinate rainbow trout by intraperitoneal (i.p.) injection. We tested the proteins for their ability to elicit antibody production and protection. Thus, fish were exposed to virulent...

  15. Watershed boundaries and geographic isolation: patterns of diversification in cutthroat trout from western North America

    Directory of Open Access Journals (Sweden)

    Loxterman Janet L

    2012-03-01

    Full Text Available Abstract Background For wide-ranging species, intraspecific variation can occur as a result of reproductive isolation from local adaptive differences or from physical barriers to movement. Cutthroat trout (Oncorhynchus clarkii, a widely distributed fish species from North America, has been divided into numerous putative subspecies largely based on its isolation in different watersheds. In this study, we examined mtDNA sequence variation of cutthroat trout to determine the major phylogenetic lineages of this polytypic species. We use these data as a means of testing whether geographic isolation by watershed boundaries can be a primary factor organizing intraspecific diversification. Results We collected cutthroat trout from locations spanning almost the entire geographic range of this species and included samples from all major subspecies of cutthroat trout. Based on our analyses, we reveal eight major lineages of cutthroat trout, six of which correspond to subspecific taxonomy commonly used to describe intraspecific variation in this species. The Bonneville cutthroat trout (O. c. utah and Yellowstone cutthroat trout (O. c. bouvieri did not form separate monophyletic lineages, but instead formed an intermixed clade. We also document the geographic distribution of a Great Basin lineage of cutthroat trout; a group typically defined as Bonneville cutthroat trout, but it appears more closely related to the Colorado River lineage of cutthroat trout. Conclusion Our study indicates that watershed boundaries can be an organizing factor isolating genetic diversity in fishes; however, historical connections between watersheds can also influence the template of isolation. Widely distributed species, like cutthroat trout, offer an opportunity to assess where historic watershed connections may have existed, and help explain the current distribution of biological diversity across a landscape.

  16. Production of Homozygous Transgenic Rainbow Trout with Enhanced Disease Resistance

    OpenAIRE

    Chiou, Pinwen Peter; Chen, Maria J.; Lin, Chun-Mean; Khoo, Jenny; Larson, Jon; Holt, Rich; Leong, Jo-Ann; Thorgarrd, Gary; Chen, Thomas T.

    2013-01-01

    Previous studies conducted in our laboratory showed that transgenic medaka expressing cecropin B transgenes exhibited resistant characteristic to fish bacterial pathogens, Pseudomonas fluorescens and Vibrio anguillarum. To confirm whether antimicrobial peptide gene will also exhibit anti-bacterial and anti-viral characteristics in aquaculture important fish species, we produced transgenic rainbow trout expressing cecropin P1 or a synthetic cecropin B analog, CF-17, transgene by sperm-mediated...

  17. A second generation genetic map for rainbow trout (Oncorhynchus mykiss

    Directory of Open Access Journals (Sweden)

    Gahr Scott A

    2008-11-01

    Full Text Available Abstract Background Genetic maps characterizing the inheritance patterns of traits and markers have been developed for a wide range of species and used to study questions in biomedicine, agriculture, ecology and evolutionary biology. The status of rainbow trout genetic maps has progressed significantly over the last decade due to interest in this species in aquaculture and sport fisheries, and as a model research organism for studies related to carcinogenesis, toxicology, comparative immunology, disease ecology, physiology and nutrition. We constructed a second generation genetic map for rainbow trout using microsatellite markers to facilitate the identification of quantitative trait loci for traits affecting aquaculture production efficiency and the extraction of comparative information from the genome sequences of model fish species. Results A genetic map ordering 1124 microsatellite loci spanning a sex-averaged distance of 2927.10 cM (Kosambi and having 2.6 cM resolution was constructed by genotyping 10 parents and 150 offspring from the National Center for Cool and Cold Water Aquaculture (NCCCWA reference family mapping panel. Microsatellite markers, representing pairs of loci resulting from an evolutionarily recent whole genome duplication event, identified 180 duplicated regions within the rainbow trout genome. Microsatellites associated with genes through expressed sequence tags or bacterial artificial chromosomes produced comparative assignments with tetraodon, zebrafish, fugu, and medaka resulting in assignments of homology for 199 loci. Conclusion The second generation NCCCWA genetic map provides an increased microsatellite marker density and quantifies differences in recombination rate between the sexes in outbred populations. It has the potential to integrate with cytogenetic and other physical maps, identifying paralogous regions of the rainbow trout genome arising from the evolutionarily recent genome duplication event, and

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

    DEFF Research Database (Denmark)

    Brodersen, Jacob; Malmquist, H.J.; Landkildehus, F.

    2012-01-01

    a less benthic diet as compared to trout living in allopatry or in sympatry with charr. Furthermore, we found individual habitat specialization between littoral/benthic and pelagic trout in deep lakes. Hence, our findings indicate that for trout populations interspecific competition can drive shifts...

  19. Genetic diversity in Chilean populations of rainbow trout, Oncorhynchus mykiss

    Directory of Open Access Journals (Sweden)

    Claudia B Cárcamo

    2015-03-01

    Full Text Available The rainbow trout Oncorhynchus mykiss, was first introduced in Chile between 1905 and 1920 and is currently widely distributed in Chile from Antofagasta (23°S to Patagonia (55°S. The broad range of the geographic and climatic distributions of this species in Chile offers a unique opportunity to study the effect of naturalization of an introduced species on its genetic variability. It is of particular importance to observe the genetic variability of populations in the northern range of this species distribution, in a transition zone where a Mediterranean-type climate changes to an arid climate. The present study analyzed allozymic variability and distribution within and between populations of O. mykiss from the river basins of Elqui and Limari rivers, and six culture strains, using starch-gel protein electrophoresis. Populations were found to be in Hardy-Weinberg equilibrium and the average values of He (0.045, polymorphism (13.9% and allele per locus (1.19 are similar to rainbow trout in its native distributional range. About 77.8% of the genetic variability was within population, similar to the variability reported for wild populations in the northern hemisphere. However, a marked genetic differentiation between wild populations was also found. This is likely to be the consequence of initial founder effects followed by subsequent introgression of resident populations caused by reseeding with trout of different origins in both basins.

  20. NUTRITIVE VALUE OF TROUT (ONCORHYNCHUS MYKISS FARMED IN ADRIATIC SEA

    Directory of Open Access Journals (Sweden)

    Tibor Janči

    2013-01-01

    Full Text Available The aim of this study was to determine the chemical composition of fresh and cold smoked rainbow trout fillets (Oncorhynchus mykiss farmed in the Adriatic sea by measuring water, fat, protein, salt and ash content, fatty acid profile with an emphasis on eicosapentaenoic (EPA and docosahexaenoic (DHA fatty acids. Physical characteristics were determined by pH and color measurements. Analysis was performed on homogenized fish muscles without skin and bones. Determination of moisture, ash, fat and protein was conducted according to AOAC (1995. Determination of fatty acid content of previously prepared methyl esters (HRN EN ISO 5509, 2004 was conducted by gas chromatography according to HRN EN ISO 5508 (1999. Results showed that fresh rainbow trout farmed in the Adriatic sea is an excellent protein source (21.21% but has slightly lower fat (5.21% and omega-3 fatty acid content (12.52 % compared to the results of other studies. Fat and omega-3 fatty acid content was not decreased by the process of cold smoking. Overall, fresh and smoked trout farmed in the Adriatic may be regarded as food high in nutritional value.

  1. Indirect effects of introduced trout on Cascades frogs (Rana cascadae) via shared aquatic prey

    Science.gov (United States)

    Maxwell B. Joseph; Jonah Piovia-Scott; Sharon P. Lawler; Karen L. Pope

    2010-01-01

    1. The introduction of trout to montane lakes has negatively affected amphibian populations across the western United States. In northern California’s Klamath–Siskiyou Mountains, introduced trout have diminished the distribution and abundance of a native ranid frog, Rana (=Lithobates)

  2. Sensory analysis of rainbow trout, oncorhynchus mykiss, fed enriched black soldier fly prepupae, hermetia illucens

    Science.gov (United States)

    A growth trial and fillet sensory analysis were conducted to examine the effects of replacing dietary fish meal with black soldier fly (BSF) prepupae, Hermetia illucens, in rainbow trout, Oncorhynchus mykiss. A practical-type trout diet was formulated to contain 45% protein; four test diets were dev...

  3. Spinal deformities in triploid all-female rainbow trout ( Oncorhynchus mykiss )

    DEFF Research Database (Denmark)

    Madsen, Lone; Arnbjerg, J.; Dalsgaard, Inger

    2000-01-01

    A batch of experimental rainbow trout was found to have a high level of spinal deformities. An equal deformity level was found in fish from the same batch, but reared at the fish farm from where the fry originated, suggesting that the all-female triploid status of the rainbow trout might account...... for the high level of deformity....

  4. Performance of Yellowstone and Snake River Cutthroat Trout Fry Fed Seven Different Diets.

    Science.gov (United States)

    Five commercial diets and two formulated feeds were fed to initial-feeding Yellowstone cutthroat trout Oncorhynchus clarkii bouvieri fry and Snake River cutthroat trout O. clarkii spp. (currently being petitioned for classification as O. clarkii behnkei) fry for 18 weeks to evaluate fish performance...

  5. Use of naturally occurring mercury to determine the importance of cutthroat trout to Yellowstone grizzly bears

    Science.gov (United States)

    Felicetti, L.A.; Schwartz, C.C.; Rye, R.O.; Gunther, K.A.; Crock, J.G.; Haroldson, M.A.; Waits, L.; Robbins, C.T.

    2004-01-01

    Spawning cutthroat trout (Oncorhynchus clarki (Richardson, 1836)) are a potentially important food resource for grizzly bears (Ursus arctos horribilis Ord, 1815) in the Greater Yellowstone Ecosystem. We developed a method to estimate the amount of cutthroat trout ingested by grizzly bears living in the Yellowstone Lake area. The method utilized (i) the relatively high, naturally occurring concentration of mercury in Yellowstone Lake cutthroat trout (508 ± 93 ppb) and its virtual absence in all other bear foods (6 ppb), (ii) hair snares to remotely collect hair from bears visiting spawning cutthroat trout streams between 1997 and 2000, (iii) DNA analyses to identify the individual and sex of grizzly bears leaving a hair sample, (iv) feeding trials with captive bears to develop relationships between fish and mercury intake and hair mercury concentrations, and (v) mercury analyses of hair collected from wild bears to estimate the amount of trout consumed by each bear. Male grizzly bears consumed an average of 5 times more trout/kg bear than did female grizzly bears. Estimated cutthroat trout intake per year by the grizzly bear population was only a small fraction of that estimated by previous investigators, and males consumed 92% of all trout ingested by grizzly bears.

  6. Impacts of Northern Pike on stocked Rainbow Trout in Pactola Reservoir, South Dakota

    Science.gov (United States)

    Scheibel, Natalie C.; Dembkowski, Daniel J.; Davis, Jacob L.; Chipps, Steven R.

    2016-01-01

    Establishment of nonnative Northern Pike Esox lucius in Pactola Reservoir, South Dakota, has prompted concern among biologists about the influence of this species on the lake’s intensively managed salmonid fisheries. Ancedotal information suggests that catch rates of Rainbow Trout Oncorhynchus mykiss have declined while mean size and abundance of Northern Pike has increased, although quantitative information on diet and growth of the Northern Pike population is lacking. To address potential interactions between Northern Pike and Rainbow Trout, we assessed size-dependent predation by Northern Pike on Rainbow Trout and determined the relative energetic contribution of stocked Rainbow Trout to Northern Pike growth using bioenergetics modeling. Stable isotopes combined with traditional diet analyses revealed that smaller Northern Pike (accounted for 56% of their annual energy consumption. Combining estimates of Northern Pike predation with production costs of catchable-size Rainbow Trout revealed that annual economic losses ranged from US$15,259 to $24,801 per year. Over its lifespan, an age-10 Northern Pike was estimated to consume ~117 Rainbow Trout worth approximately $340. Thus, Northern Pike predation substantially influences salmonid management initiatives and is likely a primary factor contributing to reduced Rainbow Trout abundance and return to anglers in Pactola Reservoir. Strategies for reducing Northern Pike predation on Rainbow Trout include increasing the size of stocked fish or altering the timing and spatial distribution of stocking events.

  7. Heavy metal contamination and hepatic toxicological responses in brown trout (Salmo trutta from the Kerguelen Islands

    Directory of Open Access Journals (Sweden)

    Ali Jaffal

    2015-09-01

    Full Text Available The Kerguelen Islands include various species of freshwater fish such as brown trout (Salmo trutta. These trout are among the most isolated from direct anthropogenic impact worldwide. This study was designed to analyse cadmium (Cd and copper (Cu concentrations in the liver of Kerguelen brown trout, and to assess the possible impacts of these metals on hepatic histopathology and oxidative stress parameters (superoxide dismutase and catalase activity and glutathione levels. Trout were caught in the Château River, the Studer Lakes and the Ferme Pond, close to the scientific station of the Kerguelen Islands, corresponding to three morphotypes (river, lake and station. Kerguelen trouts’ hepatic concentrations of Cd and Cur were similar to those reported in previous studies in salmonids populations from areas under anthropological impacts. Clear hepatic disturbances (fibrosis, nuclear alteration, increased immune response, melanomacrophage centres [MMCs] were observed in all tested trout. A similar histo-pathological trend was observed among the trout from the three morphotypes but anti-oxidative responses were higher in the trout from the “station” morphotype. Hepatic alterations and the presence of MMCs in the livers of Kerguelen brown trout may be related to the high levels of Cd and Cu measured in this fish at all sampling sites.

  8. Larval long-toed salamanders incur nonconsumptive effects in the presence of nonnative trout

    Science.gov (United States)

    Kenison, Erin K.; Litt, Andrea R.; Pilliod, David; McMahon, Thomas E.

    2016-01-01

    Predators can influence prey directly through consumption or indirectly through nonconsumptive effects (NCEs) by altering prey behavior, morphology, and life history. We investigated whether predator-avoidance behaviors by larval long-toed salamanders (Ambystoma macrodactylum) in lakes with nonnative trout result in NCEs on morphology and development. Field studies in lakes with and without trout were corroborated by experimental enclosures, where prey were exposed only to visual and chemical cues of predators. We found that salamanders in lakes with trout were consistently smaller than in lakes without trout: 38% lower weight, 24% shorter body length, and 29% shorter tail length. Similarly, salamanders in protective enclosures grew 2.9 times slower when exposed to visual and olfactory trout cues than when no trout cues were present. Salamanders in trout-free lakes and enclosures were 22.7 times and 1.48 times, respectively, more likely to metamorphose during the summer season than those exposed to trout in lakes and/or their cues. Observed changes in larval growth rate and development likely resulted from a facultative response to predator-avoidance behavior and demonstrate NCEs occurred even when predation risk was only perceived. Reduced body size and growth, as well as delayed metamorphosis, could have ecological consequences for salamander populations existing with fish if those effects carry-over into lower recruitment, survival, and fecundity.

  9. Spawning migration of sea trout ( Salmo trutta (L)) in a Danish river

    DEFF Research Database (Denmark)

    Aarestrup, Kim; Jepsen, Niels

    1998-01-01

    trout ascended the river. They were tracked every third day, for up to six months, until death or descent. Great variation was found in migration pattern and duration of river residence. Some fish spawned and left the river, some died after spawning, while others died unspent. The sea trout preferred...... of a fish ladder...

  10. Daytime habitat selection for juvenile parr brown trout (Salmo trutta) in small lowland streams

    DEFF Research Database (Denmark)

    Conallin, J.; Boegh, E.; Olsen, M.

    2014-01-01

    Physical habitat is important in determining the carrying capacity of juvenile brown trout, and within freshwater management. Summer daytime physical habitat selection for the parr lifestage (7-20 cm) juvenile brown trout (Salmo trutta) was assessed in 6 small lowland streams. Habitat preference ...

  11. Conservation of Yellowstone Cutthroat Trout in Yellowstone National Park: A Case Study

    Science.gov (United States)

    Duncan, Michael B.; Murphy, Brian R.; Zale, Alexander V.

    2009-01-01

    The Yellowstone cutthroat trout (YCT; "Oncorhynchus clarki bouvieri") has become a species of special concern for Yellowstone National Park (YNP) fisheries biologists. Although this subspecies formerly occupied a greater area than any other inland cutthroat trout, the current distribution of YCT is now limited to several watersheds within the…

  12. Organic diets are equally good for rainbow trout fry as conventional diets

    DEFF Research Database (Denmark)

    Madsen, Lone; Ingerslev, Hans Christian; Dalsgaard, Inger

    2014-01-01

    Rainbow trout (Oncorhynchus mykiss) is the dominant fish species in Danish freshwater aquaculture and the annual production is about 30.000 tonnes. Only a minor part of this production is organic, but the proportion of farmed organic rainbow trout is continuously increasing. The aim of the projec...

  13. Effects of phytoestrogens on growth-related and lipogenic genes in rainbow trout (Oncorhynchus mykiss)

    Science.gov (United States)

    The objective of the current study was to determine whether estradiol (E2) or the primary soy phytoestrogens genistein and daidzein regulate expression of growth-related and lipogenic genes in rainbow trout. Juvenile rainbow trout (5 mon, 65.8 ± 1.8 g) received intraperitoneal injections of E2, gen...

  14. Estrogenic effect of propylparaben (propylhydroxybenzoate) in rainbow trout Oncorhynchus mykiss after exposure via food and water

    DEFF Research Database (Denmark)

    Bjerregaard, Poul; Andersen, Dorthe N; Pedersen, Knud L

    2003-01-01

    The estrogenic effect of propylparaben was investigated in a rainbow trout Oncorhynchus mykiss test system. Propylparaben was administered orally to sexually immature rainbow trout every second day for up to 10 days in doses between 7 and 1830 mg kg(-1) 2 d(-1) and in the water at 50 and 225 micr...

  15. Yersiniosis outbreak in rainbow trout at fish farm in Oromia Regional ...

    African Journals Online (AJOL)

    This study presents the results of an investigation conducted on an outbreak of Yersiniosis (Enteric red mouth disease) caused by Yersinia ruckeri at a rainbow trout farm situated at Adaba, Oromia Regional State, Ethiopia. Seven diseased rainbow trout fish having average weight 80 - 100 grams and aged 9 months, were ...

  16. A hedonic price analysis of the outfitter market for trout fishing in the Rocky Mountain West

    Science.gov (United States)

    Heidi M. Pitts; Jennifer A. Thacher; Patricia A. Champ; Robert P. Berrens

    2012-01-01

    Trout is the most popular sport fish in Montana, Wyoming, Colorado, and New Mexico where fishing outfitters bring revenues to many rural economies. This article uses the hedonic pricing method on a monopolistically competitive outfitter market in those four states to examine angler values for trout fishing characteristics. A total of 1,685 fishing trip observations...

  17. Aquatic and terrestrial invertebrate drift in southern Appalachian Mountain streams: implications for trout food resources

    Science.gov (United States)

    Eric D. Romaniszyn; John J. Jr. Hutchens; J. Bruce Wallance

    2007-01-01

    We characterised aquatic and terrestrial invertebrate drift in six south-western North Carolina streams and their implications for trout production. Streams of this region typically have low standing stock and production of trout because of low benthic productivity. However, little is known about the contribution of terrestrial invertebrates entering drift, the factors...

  18. Estrogenic effect of dietary 4-tert-octylphenol in rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Pedersen, Kristine H; Pedersen, Søren N; Pedersen, Knud L

    2003-01-01

    The estrogenic effect of dietary 4-tert-octylphenol (octylphenol) in rainbow trout Oncorhynchus mykiss was investigated. Octylphenol was administered orally to sexually immature rainbow trout every second day for 11 days in doses between 0.4 and 50 mgkg(-1)2 d(-1). Plasma vitellogenin was measured...

  19. The global impact of alien trout species — a review; with reference ...

    African Journals Online (AJOL)

    Rainbow and brown trout have been introduced into at least 82 countries, where they have significantly impacted indigenous fish, aquatic invertebrates and amphibians. In many studies the second, and sometimes the first, most serious identified threat to indigenous aquatic fauna is introduced fish species. Brown trout ...

  20. California golden trout and climate change: Is their stream habitat vulnerable to climate warming?

    Science.gov (United States)

    Kathleen R. Matthews

    2010-01-01

    The California golden trout (CGT) Oncorhynchus mykiss aguabonita is one of the few native high-elevation fish in the Sierra Nevada. They are already in trouble because of exotic trout, genetic introgression, and degraded habitat, and now face further stress from climate warming. Their native habitat on the Kern Plateau meadows mostly in the Golden...

  1. An environmental DNA marker for detecting nonnative brown trout (Salmo trutta)

    Science.gov (United States)

    K. J. Carim; T. M. Wilcox; M. Anderson; D. Lawrence; Michael Young; Kevin McKelvey; Michael Schwartz

    2016-01-01

    Brown trout (Salmo trutta) are widely introduced in western North America where their presence has led to declines of several native species. To assist conservation efforts aimed at early detection and eradication of this species, we developed a quantitative PCR marker to detect the presence of brown trout DNA in environmental samples. The marker strongly...

  2. Ecology and population status of trout-perch (Percopsis omiscomaycus) in western Lake Erie

    Science.gov (United States)

    Kocovsky, Patrick; Stoneman, Andrea T.; Kraus, Richard T.

    2014-01-01

    Trout-perch Percopsis omiscomaycus is among the most abundant benthic species in Lake Erie, but comparatively little is known about its ecology. Although others have conducted extensive studies on trout-perch ecology, those efforts predated invasions of white perch Morone americana, Dreissena spp., Bythotrephes longimanus and round goby Neogobius melanostomus, suggesting the need to revisit past work. Trout-perch were sampled with bottom trawls at 56 sites during June and September 2010. We examined diets, fecundity, average annual mortality, sex ratio, and long-term population trends at sites sampled since 1961. Trout-perch abundance fluctuated periodically, with distinct shorter- (4-year) and longer-term (over period of 50 years) fluctuations. Males had higher average annual mortality than females. Both sexes were equally abundant at age 0, but females outnumbered males 4:1 by age 2. Diets of trout-perch were dominated by macroinvertebrates, particularly chironomids and Hexagenia sp. Size distributions of trout-perch eggs varied widely and exhibited multiple modes indicative of protracted batch spawning. A review of the few other studies of trout-perch revealed periodic fluctuations in sex ratio of adults, which in light of our evidence of periodicity in abundance suggests the potential for sex-ratio-mediated intrinsic population regulation. Despite the introduction of numerous invasive species in Lake Erie, trout-perch remain one of the most abundant benthic invertivores and the population is relatively stable.

  3. Preliminary study of food habits in the Japanese clawed salamander larvae (Onychodactylus japonicus) in a mountain brook of the Kiso River system

    OpenAIRE

    Teruhiko, Takahara; Motomi, Genkai-Kato; Hitoshi, MIYASAKA; Yukihiro, Kohmatsu

    2011-01-01

    To evaluate food habits of the Japanese clawed salamander larvae (Onychodactylus japonicus), we examined stomach contents of 22 individuals collected from a natural mountain brook in a tributary of the Kurokawa River in Kiso Fukushima, Nagano Prefecture, central Japan. Their diet composition did not differ between fast and slow current conditions. The diet reflected the natural benthos communities of the brook, in which mayfly nymphs and caddisfly larvae accounted for 70–88%. The salamander l...

  4. Influence of small hydropower plants on brown trout (Salmo trutta L. population in Mislinja River

    Directory of Open Access Journals (Sweden)

    Blaž Cokan

    2013-12-01

    Full Text Available The brown trout (Salmo trutta L. in the Mislinja River has been endangered for years because of small hydroelectric power plants. To find out how they are affecting the population of the brown trout in the Mislinja River, we conducted a sampling of the brown trout, using a generating set. We measured the length and weight of all caught specimens and analysed the obtained data. The results are presented in this paper, e.g., biomass, estimations of abundance, average weight, average length and number of captured brown trout. We discovered that the population of the brown trout has decreased in all the sections where water has been taken away for small hydroelectric power plants.

  5. The influence of social status on hepatic glucose metabolism in rainbow trout Oncorhynchus mykiss.

    Science.gov (United States)

    Gilmour, Kathleen M; Kirkpatrick, Sheryn; Massarsky, Andrey; Pearce, Brenda; Saliba, Sarah; Stephany, Céleste-Élise; Moon, Thomas W

    2012-01-01

    The effects of chronic social stress on hepatic glycogen metabolism were examined in rainbow trout Oncorhynchus mykiss by comparing hepatocyte glucose production, liver glycogen phosphorylase (GP) activity, and liver β-adrenergic receptors in dominant, subordinate, control, fasted, and cortisol-treated fish. Hepatocyte glucose production in subordinate fish was approximately half that of dominant fish, reflecting hepatocyte glycogen stores in subordinate trout that were just 16% of those in dominant fish. Fasting and/or chronic elevation of cortisol likely contributed to these differences based on similarities among subordinate, fasted, and cortisol-treated fish. However, calculation of the "glycogen gap"--the difference between glycogen stores used and glucose produced--suggested an enhanced gluconeogenic potential in subordinate fish that was not present in fasted or cortisol-treated trout. Subordinate, fasted, and cortisol-treated trout also exhibited similar GP activities (both total activity and that of the active or a form), and these activities were in all cases significantly lower than those in control trout, perhaps reflecting an attempt to protect liver glycogen stores or a modified capacity to activate GP. Dominant trout exhibited the lowest GP activities (20%-24% of the values in control trout). Low GP activities, presumably in conjunction with incoming energy from feeding, allowed dominant fish to achieve the highest liver glycogen concentrations (double the value in control trout). Liver membrane β-adrenoceptor numbers (assessed as the number of (3)H-CGP binding sites) were significantly lower in subordinate than in dominant trout, although this difference did not translate into attenuated adrenergic responsiveness in hepatocyte glucose production in vitro. Transcriptional regulation, likely as a result of fasting, was indicated by significantly lower β(2)-adrenoceptor relative mRNA levels in subordinate and fasted trout. Collectively, the data

  6. Assessing effects of stocked trout on nongame fish assemblages in southern Appalachian Mountain streams

    Science.gov (United States)

    Weaver, D.; Kwak, Thomas J.

    2013-01-01

    Fisheries managers are faced with the challenge of balancing the management of recreational fisheries with that of conserving native species and preserving ecological integrity. The negative effects that nonnative trout species exert on native trout are well documented and include alteration of competitive interactions, habitat use, and production. However, the effects that nonnative trout may exert on nongame fish assemblages are poorly understood. Our objectives were to quantify the effects of trout stocking on native nongame fish assemblages intensively on one newly stocked river, the North Toe River, North Carolina, and extensively on other southern Appalachian Mountain streams that are annually stocked with trout. In the intensive study, we adopted a before-after, control-impact (BACI) experimental design to detect short-term effects on the nongame fish assemblage and found no significant differences in fish density, species richness, species diversity, or fish microhabitat use associated with trout stocking. We observed differences in fish microhabitat use between years, however, which suggests there is a response to environmental changes, such as the flow regime, which influence available habitat. In the extensive study, we sampled paired stocked and unstocked stream reaches to detect long-term effects from trout stocking; however, we detected no differences in nongame fish density, species richness, species diversity, or population size structure between paired sites. Our results revealed high inherent system variation caused by natural and anthropogenic factors that appear to overwhelm any acute or chronic effect of stocked trout. Furthermore, hatchery-reared trout may be poor competitors in a natural setting and exert a minimal or undetectable impact on native fish assemblages in these streams. These findings provide quantitative results necessary to assist agencies in strategic planning and decision making associated with trout fisheries, stream

  7. Comparison of pigment cell ultrastructure and organisation in the dermis of marble trout and brown trout, and first description of erythrophore ultrastructure in salmonids

    Science.gov (United States)

    Djurdjevič, Ida; Kreft, Mateja Erdani; Sušnik Bajec, Simona

    2015-01-01

    Skin pigmentation in animals is an important trait with many functions. The present study focused on two closely related salmonid species, marble trout (Salmo marmoratus) and brown trout (S. trutta), which display an uncommon labyrinthine (marble-like) and spot skin pattern, respectively. To determine the role of chromatophore type in the different formation of skin pigment patterns in the two species, the distribution and ultrastructure of chromatophores was examined with light microscopy and transmission electron microscopy. The presence of three types of chromatophores in trout skin was confirmed: melanophores; xanthophores; and iridophores. In addition, using correlative microscopy, erythrophore ultrastructure in salmonids was described for the first time. Two types of erythrophores are distinguished, both located exclusively in the skin of brown trout: type 1 in black spot skin sections similar to xanthophores; and type 2 with a unique ultrastructure, located only in red spot skin sections. Morphologically, the difference between the light and dark pigmentation of trout skin depends primarily on the position and density of melanophores, in the dark region covering other chromatophores, and in the light region with the iridophores and xanthophores usually exposed. With larger amounts of melanophores, absence of xanthophores and presence of erythrophores type 1 and type L iridophores in the black spot compared with the light regions and the presence of erythrophores type 2 in the red spot, a higher level of pigment cell organisation in the skin of brown trout compared with that of marble trout was demonstrated. Even though the skin regions with chromatophores were well defined, not all the chromatophores were in direct contact, either homophilically or heterophilically, with each other. In addition to short-range interactions, an important role of the cellular environment and long-range interactions between chromatophores in promoting adult pigment pattern

  8. Low-angle normal faults in the south-central Brooks Range fold and thrust belt, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Gottschalk, R.R.; Oldow, J.S.

    1988-05-01

    A north-south structural transect through the south-central Brooks Range, Alaska, exposes three lithologically distinct, fault-bounded packages of rock, all regionally metamorphosed during the Late Jurassic to Early Cretaceous contractional deformation that formed much of the Brooks Range fold and thrust belt. These are, from south to north and structurally highest to lowest, (1) the prehnite-pumpellyite facies ophiolitic rocks of the Angayucham terrane, (2) the low-grade metasedimentary rocks of the Rosie Creek allochthon, and (3) pumpellyite-actinolite to glaucophane-epidote facies metamorphic rocks of the schist belt. The presence of rocks metamorphosed and deformed at shallow levels of the fold and thrust belt (the Angayucham terrane and Rosie Creek allochthon) lying structurally above rocks representing the deepest exposed levels of the fold and thrust belt (the schist belt) indicates that the imbricate stack is disrupted by south-dipping, low-angle normal faults along the southern margin of the Brooks Range. The authors propose that normal faults developed in response to the uplift of the schist belt and the overlying metasedimentary and ophiolitic allochthons by north-directed thrusting in the late Early Cretaceous. Thrusting resulting in the oversteepening of the imbricate stack, causing compensatory normal faulting along the southern flank of the ramp structure. Normal faults may have provided at least local structural control of the locus of Albian and younger sedimentation in the Koyukuk basin. 34 references.

  9. Stratigraphic controls on lateral variations in the structural style of northeastern Brooks Range, Arctic National Wildlife Refuge, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, W.K.; Hanks, C.L.

    1988-01-01

    The structural style of the range-front region of the northeastern Brooks Range in Arctic National Wildlife Refuge (ANWR) is strongly controlled by (1) the existence of detachment horizons in both pre-Mississippian rocks and the unconformably overlying Mississippian to Lower Cretaceous cover sequence, and (2) lithology and structural competency of the pre-Mississippian rocks. These variables strongly influence lateral changes in structural style. The Brooks Range of northwestern ANWR is dominated by a series of narrow linear anticlinoria, whereas in northeastern ANWR the Brooks Range is characterized by only two broad and strongly arcuate anticlinoria. In both areas, the anticlinoria are controlled by the geometry of a duplex bounded by a floor thrust in pre-Mississippian rocks and a roof thrust in the Kayak Shale, near the base of the cover sequence. In the west, where the pre-Mississippian partially consists of structurally competent carbonates, each anticlinorium marks a single horse in the duplex. However, in the east, pre-Mississippian rocks are relatively incompetent and each anticlinorium is cored by multiple horses. In the west, shortening above the roof thrust is by detachment folding, except where the shale detachment horizon is depositionally absent. In contrast, in eastern ANWR shortening above the roof thrust is by major thrust duplication of the entire cover sequence, perhaps due to lithology and thickness changes within the detachment horizon.

  10. Appraisal of the water resources of the Big Sioux aquifer, Brookings, Deuel, and Hamlin Counties, South Dakota

    Science.gov (United States)

    Koch, Neil C.

    1980-01-01

    A finite-difference method digital model was used to simulate steady-state conditions of the Big Sioux aquifer in Brookings, Deuel, and Hamlin Counties, S. Dak. Average annual water levels in the Big Sioux aquifer and average base flow discharge 58 cubic feet per second on the Big Sioux River near Brookings were based on the period 1970 through 1976. The computer model was used to model transient conditions by simulating monthly periods from April through August 1976. Evapotranspiration and pumpage changes were made for each month. A computer simulation was made without irrigation pumpage which resulted in an increase in the base flow from 0.66 to 9 cubic feet per second for August 1976 in the Big Sioux River near Brookings. Two transient simulations , one with the drought conditions of 1976 and one using all the pumpage allowed by irrigation permits approved by the State as of February 1979 showed, as a result of pumpage, that there was a decrease in evapotranspiration and a decrease in discharge to streams which amounts to 26 and 31% of the total groundwater pumped. Groundwater and surface water in the study area are primarily calcium bicarbonate types and are chemically suitable for irrigation with respect to sodium hazard. Sepcific conductance of groundwater ranged from 407 to 1,790 micromhos per centimeter at 25 Celsius. (USGS)

  11. Selective breeding provides an approach to increase resistance of rainbow trout ( Onchorhynchus mykiss ) to the diseases, enteric redmouth disease, rainbow trout fry syndrome, and viral haemorrhagic septicaemia

    DEFF Research Database (Denmark)

    Henryon, M.; Berg, P.; Olesen, Niels Jørgen

    2005-01-01

    In this study, we reasoned that if we challenged rainbow trout with the causative agents of enteric redmouth disease (ERM), rainbow trout fry syndrome (RTFS), and viral haemorrhagic septicaemia (VHS), we would: 1) detect additive genetic variation for resistance to ERM, RTFS, and VHS; and 2) find......, RTFS, and VHS will be successful, providing a complementary approach to control these diseases. The weak genetic correlations suggest that it should be relatively easy to improve resistance to each of the diseases simultaneously.......In this study, we reasoned that if we challenged rainbow trout with the causative agents of enteric redmouth disease (ERM), rainbow trout fry syndrome (RTFS), and viral haemorrhagic septicaemia (VHS), we would: 1) detect additive genetic variation for resistance to ERM, RTFS, and VHS; and 2) find...... that resistance of the trout to ERM and RTFS are favourably correlated genetically, while resistance to VHS is unfavourably correlated with resistance to ERM and RTFS. We tested these premises by challenging 63 full-sib families of rainbow trout (50 sires, 38 dams) with Yersinia ruckeri, Flavobacterium...

  12. Streambed-material characteristics and surface-water quality, Green Pond Brook and tributaries, Picatinny Arsenal, New Jersey, 1983-90

    Science.gov (United States)

    Storck, D.A.; Lacombe, Pierre

    1996-01-01

    This report presents the results of a study designed to determine whether Green Pond Brook and its tributaries contain contaminated streambed sediments and to characterize the quaity of water in the brook. Results of previous investigations at Picatinny Arsenal, Morris County, New Jersey, indicate that significant contamination of ground water, surface water, and soil is present at the arsenal. Forty-five streambed-material samples were collected for analysis to determine whether contaminants have migrated to the brook from the surrounding area. Samples were analyzed for trace elements, base/neutral- and acid-etractable compounds, insecticides, and other constituents. Results of an electromagnetic-conductivity and natural-gamma-ray survey were used to describe the distribution of particle sizes in streambed and substreambed sediments. Historical results of analyses of streambed-material and surface-water samples also are presented. Samples of streambed material from three areas in Green Pond Brook and its tributaries contained organic and (or) inorganic constituents in concentrations greater than those typically found at the arsenal. These areas are Green Pond Brook, from the area near the outflow of Picatinny Lake downstream to Farley Avenue; Bear Swamp Brook, from the area near building 241 downstream to the confluence with Green Pond Brook; and Green Pond Brook, from the open burning area downstream to the dam near building 1178. Contaminants identified include trace elements, polynuclear aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine insecticides. Surface water in Green Pond Brook contained several volatile organic compounds, including trichloroethylene, tetrachloroethylene, and 1,2-dichloroethylene, at maximum concen- trations of 3.8, 4.6, and 11 micrograms per liter, respectively. Volatilization is expected to remove volatile organic compounds in the steep, fast- flowing reaches of the brook. No organic or inorganic constituents were

  13. Effects of stream enclosures on drifting invertebrates and fish growth

    Science.gov (United States)

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

    2006-01-01

    Stream ecologists often use enclosure experiments to investigate predator-prey interactions and competition within and among fish species. The design of enclosures, manipulation of species densities, and method of replication may influence experimental results. We designed an experiment with enclosure cages (1 m2, 6-mm mesh) to examine the relative influence of fish size, density, and prey availability on growth of brown trout (Salmo trutta), brook trout (Salvelinus fontinalis), and slimy sculpin (Cottus cognatus) within enclosures in Valley Creek, Minnesota. In addition, we examined water flow and invertebrate drift entering enclosures and in open riffles to investigate whether enclosures reduced the supply of invertebrate prey. Growth of small (age-0) brook and brown trout was not influenced by fish density, but growth of larger (age-1) trout generally decreased as density increased. Sculpin growth was not related to fish size or density, but increased with mean size of invertebrates in the drift. Enclosures reduced water flow and tended to reduce invertebrate drift rate, although total drift rate (ind./min), total drift density (ind./m3), and mean size of invertebrates were not significantly different inside enclosures compared to adjacent stream riffles. Enclosures had no effect on drift rate or size of Gammarus pseudolimnaeus, the main prey item for trout and sculpin in Valley Creek. Overall, our analyses indicated that reductions of prey availability by enclosures did not influence fish growth. Trout growth may have been limited at larger sizes and densities because of increased activity costs of establishing and defending territories, whereas sculpin growth was related to availability of large prey, a factor not influenced by enclosures. ?? 2006 by The North American Benthological Society.

  14. Biology, status, and management of the yellowstone cutthroat trout

    Science.gov (United States)

    Gresswell, R.E.

    2011-01-01

    Yellowstone cutthroat trout Oncorhynchus clarkii bouvieri were historically distributed in the Yellowstone River drainage (Montana and Wyoming) and the Snake River drainage (Wyoming, Idaho, Utah, Nevada, and probably Washington). Individual populations evolved distinct life history characteristics in response to the diverse environments in which they were isolated after the last glaciation. Anthropogenic activities have resulted in a substantial decline (42% of the historical range is currently occupied; 28% is occupied by core [genetically unaltered] populations), but the number of extant populations, especially in headwater streams, has precluded listing of this taxon under the Endangered Species Act. Primary threats to persistence of Yellowstone cutthroat trout include (1) invasive species, resulting in hybridization, predation, disease, and interspecific competition; (2) habitat degradation from human activities such as agricultural practices, water diversions, grazing, dam construction, mineral extraction, grazing, timber harvest, and road construction; and (3) climate change, including an escalating risk of drought, wildfire, winter flooding, and rising temperatures. Extirpation of individual populations or assemblages has led to increasing isolation and fragmentation of remaining groups, which in turn raises susceptibility to the demographic influences of disturbance (both human and stochastic) and genetic factors. Primary conservation strategies include (1) preventing risks associated with invasive species by isolating populations of Yellowstone cutthroat trout and (2) connecting occupied habitats (where possible) to preserve metapopulation function and the expression of multiple life histories. Because persistence of isolated populations may be greater in the short term, current management is focused on isolating individual populations and restoring habitats; however, this approach implies that humans will act as dispersal agents if a population is

  15. Hydropedology at Hubbard Brook: Differentiating soil functional units with shallow ground water response data

    Science.gov (United States)

    Gannon, J. P.; McGuire, K. J.; Bailey, S. W.

    2011-12-01

    Headwater catchments dominate the drainage basins of larger rivers and determine the water quality of downstream water bodies. In these catchments, hydrology strongly influences soil development and soil chemistry, thereby determining stream water quality. This study aims to explain spatial and temporal variations in stream water chemistry at the headwater catchment scale utilizing a hydropedological approach. Hydropedologic units (HPUs), defined by differing soil morphological characteristics and hypothesized to be indicative of different hydrologic flow regimes, provide a framework for describing the function of different soil types in a catchment. Relationships between HPUs and shallow groundwater responses measured by 10-minute water level data were examined for 50 wells throughout the 41 ha watershed 3 at Hubbard Brook Experimental Forest. Relationships between hydropedological units and observed water table fluctuations are presented. Comparisons were made between descriptive statistics of each time series as well as rainfall-response analyses. When grouped by HPU, wells in the catchment were shown to exhibit statistically significant differences in overall water table dynamics as well as distinct threshold responses to precipitation and antecedent wetness. As HPUs are hypothesized to occur in predictable landscape positions, the results of this study suggest a hydropedological approach may be a useful approach for describing catchment runoff response as well as spatial patterns in soil moisture, soil chemistry, and therefore stream water chemistry.

  16. Mercury speciation comparison. BrooksApplied Laboratories and Eurofins Frontier Global Sciences

    Energy Technology Data Exchange (ETDEWEB)

    Bannochie, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Wilmarth, W. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-12-16

    The Savannah River National Laboratory (SRNL) was tasked with preparing and shipping samples for Hg speciation by Eurofins Frontier Global Sciences (FGS), Inc. in Bothell, WA on behalf of the Savannah River Remediation (SRR) Mercury Program Team. These samples were analyzed for seven species including: total mercury, dissolved mercury, inorganic mercury ((Hg(I) and Hg(II)), elemental mercury, methylmercury, ethylmercury, and dimethylmercury, with an eighth species, particulate mercury, calculated from the difference between total and dissolved mercury after subtracting the elemental mercury. The species fraction of total mercury measured has ranged broadly from a low of 32% to a high of 146%, though the vast majority of samples have been <100%. This can be expected since one is summing multiple values that each have at least a ± 20% measurement uncertainty. Two liquid waste tanks particularly important to understanding the distribution of mercury species in the Savannah River Site (SRS) Tank Farm were selected for a round robin analysis by Eurofins FGS and BrooksApplied Laboratories (BAL). The analyses conducted by BAL on the Tank 22 and 38 samples and their agreement with those obtained from Eurofins FGS for total mercury, dissolved mercury, methylmercury, ethylmercury, and dimethylmercury provide a strong degree of confidence in these species measurements

  17. NASA Plum Brook's B-2 Test Facility: Thermal Vacuum and Propellant Test Facility

    Science.gov (United States)

    Kudlac, Maureen T.; Weaver, Harold F.; Cmar, Mark D.

    2012-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) Plum Brook Station (PBS) Spacecraft Propulsion Research Facility, commonly referred to as B-2, is NASA's third largest thermal vacuum facility. It is the largest designed to store and transfer large quantities of liquid hydrogen and liquid oxygen, and is perfectly suited to support developmental testing of upper stage chemical propulsion systems as well as fully integrated stages. The facility is also capable of providing thermal-vacuum simulation services to support testing of large lightweight structures, Cryogenic Fluid Management (CFM) systems, electric propulsion test programs, and other In-Space propulsion programs. A recently completed integrated system test demonstrated the refurbished thermal vacuum capabilities of the facility. The test used the modernized data acquisition and control system to monitor the facility. The heat sink provided a uniform temperature environment of approximately 77 K. The modernized infrared lamp array produced a nominal heat flux of 1.4 kW/sq m. With the lamp array and heat sink operating simultaneously, the thermal systems produced a heat flux pattern simulating radiation to space on one surface and solar exposure on the other surface.

  18. Reconstructing the demographic history of divergence between European river and brook lampreys using approximate Bayesian computations

    Directory of Open Access Journals (Sweden)

    Quentin Rougemont

    2016-04-01

    Full Text Available Inferring the history of isolation and gene flow during species divergence is a central question in evolutionary biology. The European river lamprey (Lampetra fluviatilis and brook lamprey (L. planeri show a low reproductive isolation but have highly distinct life histories, the former being parasitic-anadromous and the latter non-parasitic and freshwater resident. Here we used microsatellite data from six replicated population pairs to reconstruct their history of divergence using an approximate Bayesian computation framework combined with a random forest model. In most population pairs, scenarios of divergence with recent isolation were outcompeted by scenarios proposing ongoing gene flow, namely the Secondary Contact (SC and Isolation with Migration (IM models. The estimation of demographic parameters under the SC model indicated a time of secondary contact close to the time of speciation, explaining why SC and IM models could not be discriminated. In case of an ancient secondary contact, the historical signal of divergence is lost and neutral markers converge to the same equilibrium as under the less parameterized model allowing ongoing gene flow. Our results imply that models of secondary contacts should be systematically compared to models of divergence with gene flow; given the difficulty to discriminate among these models, we suggest that genome-wide data are needed to adequately reconstruct divergence history.

  19. Pillow basalts of the Angayucham terrane: oceanic plateau and island crust accreted to the Brooks Range

    Science.gov (United States)

    Pallister, J.S.; Budahn, J.R.; Murchey, B.L.

    1989-01-01

    The Angayucham Mountains (north margin of the Yukon-Koyukuk province) are made up of an imbricate stack of four to eight east-west trending, steeply dipping, fault slabs composed of Paleozoic, Middle to Late Triassic, and Early Jurassic oceanic upper crustal rocks. Field relations and geochemical characteristics of the basaltic rocks suggest that the fault slabs were derived from an oceanic plateau or island setting and were emplaced onto the Brooks Range continental margin. The basalts are variably metamorphosed to prehnite-pumpellyite and low-greenschist facies. Major element analyses suggest that many are hypersthene-normative olivine tholeiites. The Triassic and Jurassic basalts are geochemically most akin to modern oceanic plateau and island basalts. Field evidence also favors an oceanic plateau or island setting. The great composite thickness of pillow basalt probably resulted from obduction faulting, but the lack of fault slabs of gabbro or peridotite suggests that obduction faults did not penetrate below oceanic layer 2, a likely occurrence if layer 2 were anomalously thick, as in the vicinity of an oceanic island. -from Authors

  20. Risk factors in schizophrenia: the Stony Brook High-Risk Project.

    Science.gov (United States)

    Weintraub, S

    1987-01-01

    The goals of the Stony Brook High-Risk Project are to identify precursor patterns, environmental stressors, and protective factors that are differentially predictive of psychopathology. In phase I we assessed 219 families and 544 children aged 7-15, including 31 families and 80 children with a schizophrenic parent, 70 families and 154 children with a unipolar depressed parent, 58 families and 134 children with a bipolar parent, and 60 normal control families with 176 children. A 3-year followup was conducted on 84 percent of the sample, and an additional followup is underway. Our data include measures of: (1) psychological functioning of the parents; (2) the environment, including family functioning, marital adjustment, and parenting practices; (3) child adjustment, including peer, or teacher, parent, and self-ratings; (4) early signs or precursors to the development of schizophrenia or affective disorder, including cognitive slippage, attentional deficits, hedonic capacity, depressogenic attributional styles, and subsyndromal affective patterns. Considerable deviance in family functioning, expressed in conflict, marital discord, and parenting skills, was characteristic of the families with an ill parent, and this discord was related to child adjustment. Children with a schizophrenic parent showed multiple and extensive cognitive, attentional, and social impairments, and at the 18+ followup, 22.8 percent of them compared with 9.6 percent of the normal controls were assigned a DSM-III diagnosis.

  1. Lateral continuity of the Blarney Creek Thrust, Doonerak Windown, Central Brooks Range, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Seidensticker, C.M.; Julian, F.E.; Phelps, J.C.; Oldow, J.S.; Avellemant, H.G.

    1985-04-01

    The contact between Carboniferous and lower Paleozoic rocks, exposed along the northern margin of the Doonerak window in the central Brooks Range, is a major thrust fault called the Blarney Creek thrust (BCT). The BCT has been traced over a distance of 25 km, from Falsoola Mountain to Wien Mountain. The tectonic nature of this contact is demonstrated by: (1) omission of stratigraphic units above and below the BCT; (2) large angular discordance in orientation of first-generation cleavage at the BCT; (3) numerous thrust imbricates developed in the upper-plate Carboniferous section that sole into the BCT; and (4) truncation of an upper-plate graben structure at the BCT. Lack of evidence for pre-Carboniferous deformation in the lower plate casts doubt on the interpretation of the contact as an angular unconformity. However, the localized presence below the BCT of Mississippian Kekiktuk Conglomerate and Kayak Shale, in apparent depositional contact with lower Paleozoic rocks, suggests that the BCT follows an originally disconformable contact between the Carboniferous and lower Paleozoic rocks. The juxtaposition of younger over older rocks at the BCT is explained by calling upon the BCT to act as the upper detachment surface of a duplex structure. Duplex development involves initial imbrication of the Carboniferous section using the BCT as a basal decollement, followed by formation of deeper thrusts in the lower Paleozoic section, which ramp up and merge into the BCT.

  2. Pipeline corridors through wetlands -- Impacts on plant communities: Norris Brook Crossing Peabody, Massachusetts

    Energy Technology Data Exchange (ETDEWEB)

    Shem, L.M.; Van Dyke, G.D.; Zimmerman, R.E. [Argonne National Lab., IL (United States)

    1994-12-01

    The goal of the Gas Research Institute Wetland Corridors Program is to document impacts of existing pipelines on the wetlands they traverse. To accomplish this goal, 12 existing wetland crossings were surveyed. These sites varied in elapsed time since pipeline construction, wetland type, pipeline installation techniques, and right-of-way (ROW) management practices. This report presents the results of a survey conducted August 17--19, 1992, at the Norris Brook crossing in the town of Peabody, Essex County, Massachusetts. The pipeline at this site was installed during September and October 1990. A backhoe was used to install the pipeline. The pipe was assembled on the adjacent upland and slid into the trench, after which the backhoe was used again to fill the trench and cover the pipeline. Within two years after pipeline construction, a dense vegetative community, composed predominantly of native perennial species, had become established on the ROW. Compared with adjacent natural areas undisturbed by pipeline installation, there was an increase in purple loosestrife and cattail within the ROW, while large woody species were excluded from the ROW. As a result of the ROW`s presence, habitat diversity, edge-type habitat, and species diversity increased within the site. Crooked-stem aster, Aster prenanthoides (a species on the Massasschusetts list of plants of special concern), occurred in low numbers in the adjacent natural areas and had reinvaded the ROW in low numbers.

  3. Effect of electric barrier on passage and physical condition of juvenile and adult rainbow trout

    Science.gov (United States)

    Layhee, Megan J.; Sepulveda, Adam; Shaw, Amy; Smuckall, Matthew; Kapperman, Kevin; Reyes, Alejandro

    2016-01-01

    Electric barriers can inhibit passage and injure fish. Few data exist on electric barrier parameters that minimize these impacts and on how body size affects susceptibility, especially to nontarget fish species. The goal of this study was to determine electric barrier voltage and pulse-width settings that inhibit passage of larger bodied rainbow trout Oncorhynchus mykiss (215–410 mm fork length) while allowing passage of smaller bodied juvenile rainbow trout (52–126 mm) in a static laboratory setting. We exposed rainbow trout to 30-Hz pulsed-direct current voltage gradients (0.00–0.45 V cm−1) and pulse widths (0.0–0.7 ms) and recorded their movement, injury incidence, and mortality. No settings tested allowed all juveniles to pass while impeding all adult passage. Juvenile and adult rainbow trout avoided the barrier at higher pulse widths, and fewer rainbow trout passed the barrier at 0.7-ms pulse width compared to 0.1 ms and when the barrier was turned off. We found no effect of voltage gradient on fish passage. No mortality occurred, and we observed external bruising in 5 (7%) juvenile rainbow trout and 15 (21%) adult rainbow trout. This study may aid managers in selecting barrier settings that allow for increased juvenile passage.

  4. Glycated hemoglobin is not an accurate indicator of glycemia in rainbow trout.

    Science.gov (United States)

    Santin, A E; Searle, A J; Winston, V D; Powell, M S; Hardy, R W; Rodnick, K J

    2013-07-01

    Glycation occurs when glucose reacts non-enzymatically with proteins. This reaction depends upon time, ambient glucose concentration, and the molecular conformation of reactive amino acids. Little is known about protein glycation in fishes and the main objective of this study was to measure glycated hemoglobin (GHb) in rainbow trout, a glucose-intolerant species, under normoglycemic and hyperglycemic conditions. We also identified GHb isoforms in vivo and analyzed the structural environment surrounding potential glycation sites. Despite similar glycemia to healthy humans, GHb was an order of magnitude lower in rainbow trout (0.6%) compared with humans (6%) and was not affected by long-term hyperglycemia. Species differences in GHb appear to be related to differences in erythrocyte glucose, and differential expression and glycation of hemoglobin (Hb) isoforms may explain intraspecific differences in rainbow trout GHb. Computer analysis of glucose isomers (ringed-open and α- and β-pyranoses) interacting with the β-chain of rainbow trout HbI and HbIV, and human HbA did not reveal structural or energetic constraints for glucose binding (the initial step of glycation) for rainbow trout Hbs. Overall, there are significant differences between Hb glycation in humans and rainbow trout, and GHb does not appear to be an accurate indicator of glycemia over time in rainbow trout. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Selenium Bioaccumulation in Stocked Fish as an Indicator of Fishery Potential in Pit Lakes on Reclaimed Coal Mines in Alberta, Canada

    Science.gov (United States)

    Miller, L. L.; Rasmussen, J. B.; Palace, V. P.; Sterling, G.; Hontela, A.

    2013-07-01

    Pit lakes are a common reclamation strategy for open pit mines; however, there is a concern about their water quality and suitability as fish habitat because they are often contaminated by metals or metalloids. This study assessed the exposure of fish and invertebrates to selenium (Se) and other metals and metalloids in pit lakes formed by open pit coal mining in Tertiary (thermal coal) and in Cretaceous (metallurgical coal) bedrock. Juvenile hatchery rainbow trout, Oncorhynchus mykiss, and brook trout, Salvelinus fontinalis, were stocked into two thermal coal pit lakes (water Se water Se) and two metallurgical coal pit lakes (water Se > 15 μg/L, high water Se). Se accumulation in stocked fish and concentrations in invertebrates were characterized over a period of 2 years. In the metallurgical pits, invertebrates had higher Se concentrations and fish accumulated Se to higher levels (exceeding USEPA tissue Se guidelines) than biota in the thermal pits. Rainbow and brook trout accumulated similar concentrations of Se in their muscle and exhibited a similar relationship between whole-body and muscle Se concentrations. These results may be used by resource managers to assess compliance with whole-body tissue Se guidelines and to determine if pit lakes in coal mining areas pose a significant Se risk to wildlife or human health. The high Se exposure in metallurgical coal pits indicates that under the current mining and reclamation strategy, these lakes are not suitable for management as recreational "put and take" fisheries.

  6. Spatial segregation of spawning habitat limits hybridization between sympatric native Steelhead and Coastal Cutthroat Trout

    Science.gov (United States)

    Buehrens, T.W.; Glasgow, J.; Ostberg, Carl O.; Quinn, T.P.

    2013-01-01

    Native Coastal Cutthroat Trout Oncorhynchus clarkii clarkii and Coastal Steelhead O. mykiss irideus hybridize naturally in watersheds of the Pacific Northwest yet maintain species integrity. Partial reproductive isolation due to differences in spawning habitat may limit hybridization between these species, but this process is poorly understood. We used a riverscape approach to determine the spatial distribution of spawning habitats used by native Coastal Cutthroat Trout and Steelhead as evidenced by the distribution of recently emerged fry. Molecular genetic markers were used to classify individuals as pure species or hybrids, and individuals were assigned to age-classes based on length. Fish and physical habitat data were collected in a spatially continuous framework to assess the relationship between habitat and watershed features and the spatial distribution of parental species and hybrids. Sampling occurred in 35 reaches from tidewaters to headwaters in a small (20 km2) coastal watershed in Washington State. Cutthroat, Steelhead, and hybrid trout accounted for 35%, 42%, and 23% of the fish collected, respectively. Strong segregation of spawning areas between Coastal Cutthroat Trout and Steelhead was evidenced by the distribution of age-0 trout. Cutthroat Trout were located farther upstream and in smaller tributaries than Steelhead were. The best predictor of species occurrence at a site was the drainage area of the watershed that contributed to the site. This area was positively correlated with the occurrence of age-0 Steelhead and negatively with the presence of Cutthroat Trout, whereas hybrids were found in areas occupied by both parental species. A similar pattern was observed in older juveniles of both species but overlap was greater, suggesting substantial dispersal of trout after emergence. Our results offer support for spatial reproductive segregation as a factor limiting hybridization between Steelhead and Coastal Cutthroat Trout.

  7. Determining vaccination frequency in farmed rainbow trout using Vibrio anguillarum O1 specific serum antibody measurements.

    Directory of Open Access Journals (Sweden)

    Lars Holten-Andersen

    Full Text Available BACKGROUND: Despite vaccination with a commercial vaccine with a documented protective effect against Vibrio anguillarum O1 disease outbreaks caused by this bacterium have been registered among rainbow trout at Danish fish farms. The present study examined specific serum antibody levels as a valid marker for assessing vaccination status in a fish population. For this purpose a highly sensitive enzyme-linked immunosorbent assay (ELISA was developed and used to evaluate sera from farmed rainbow trout vaccinated against V. anguillarum O1. STUDY DESIGN: Immune sera from rainbow trout immunised with an experimental vaccine based on inactivated V. anguillarum O1 bacterin in Freund's incomplete adjuvant were used for ELISA optimisation. Subsequently, sera from farmed rainbow trout vaccinated with a commercial vaccine against V. anguillarum were analysed with the ELISA. The measured serum antibody levels were compared with the vaccine status of the fish (vaccinated/unvaccinated as evaluated through visual examination. RESULTS: Repeated immunisation with the experimental vaccine lead to increasing levels of specific serum antibodies in the vaccinated rainbow trout. The farmed rainbow trout responded with high antibody levels to a single injection with the commercial vaccine. However, the diversity in responses was more pronounced in the farmed fish. Primary visual examinations for vaccine status in rainbow trout from the commercial farm revealed a large pool of unvaccinated specimens (vaccination failure rate=20% among the otherwise vaccinated fish. Through serum analyses using the ELISA in a blinded set-up it was possible to separate samples collected from the farmed rainbow trout into vaccinated and unvaccinated fish. CONCLUSIONS: Much attention has been devoted to development of new and more effective vaccines. Here we present a case from a Danish rainbow trout farm indicating that attention should also be directed to the vaccination procedure in

  8. Predicting spatial distribution of postfire debris flows and potential consequences for native trout in headwater streams

    Science.gov (United States)

    Sedell, Edwin R; Gresswell, Bob; McMahon, Thomas E.

    2015-01-01

    Habitat fragmentation and degradation and invasion of nonnative species have restricted the distribution of native trout. Many trout populations are limited to headwater streams where negative effects of predicted climate change, including reduced stream flow and increased risk of catastrophic fires, may further jeopardize their persistence. Headwater streams in steep terrain are especially susceptible to disturbance associated with postfire debris flows, which have led to local extirpation of trout populations in some systems. We conducted a reach-scale spatial analysis of debris-flow risk among 11 high-elevation watersheds of the Colorado Rocky Mountains occupied by isolated populations of Colorado River Cutthroat Trout (Oncorhynchus clarkii pleuriticus). Stream reaches at high risk of disturbance by postfire debris flow were identified with the aid of a qualitative model based on 4 primary initiating and transport factors (hillslope gradient, flow accumulation pathways, channel gradient, and valley confinement). This model was coupled with a spatially continuous survey of trout distributions in these stream networks to assess the predicted extent of trout population disturbances related to debris flows. In the study systems, debris-flow potential was highest in the lower and middle reaches of most watersheds. Colorado River Cutthroat Trout occurred in areas of high postfire debris-flow risk, but they were never restricted to those areas. Postfire debris flows could extirpate trout from local reaches in these watersheds, but trout populations occupy refugia that should allow recolonization of interconnected, downstream reaches. Specific results of our study may not be universally applicable, but our risk assessment approach can be applied to assess postfire debris-flow risk for stream reaches in other watersheds.

  9. Temporary Restoration of Bull Trout Passage at Albeni Falls Dam, 2008 Progress Report.

    Energy Technology Data Exchange (ETDEWEB)

    Bellgraph, Brian J. [Pacific Northwest National Laboratory

    2009-03-31

    The goal of this project is to provide temporary upstream passage of bull trout around Albeni Falls Dam on the Pend Oreille River, Idaho. Our specific objectives are to capture fish downstream of Albeni Falls Dam, tag them with combination acoustic and radio transmitters, release them upstream of Albeni Falls Dam, and determine if genetic information on tagged fish can be used to accurately establish where fish are located during the spawning season. In 2007, radio receiving stations were installed at several locations throughout the Pend Oreille River watershed to detect movements of adult bull trout; however, no bull trout were tagged during that year. In 2008, four bull trout were captured downstream of Albeni Falls Dam, implanted with transmitters, and released upstream of the dam at Priest River, Idaho. The most-likely natal tributaries of bull trout assigned using genetic analyses were Grouse Creek (N = 2); a tributary of the Pack River, Lightning Creek (N = 1); and Rattle Creek (N = 1), a tributary of Lightning Creek. All four bull trout migrated upstream from the release site in Priest River, Idaho, were detected at monitoring stations near Dover, Idaho, and were presumed to reside in Lake Pend Oreille from spring until fall 2008. The transmitter of one bull trout with a genetic assignment to Grouse Creek was found in Grouse Creek in October 2008; however, the fish was not found. The bull trout assigned to Rattle Creek was detected in the Clark Fork River downstream from Cabinet Gorge Dam (approximately 13 km from the mouth of Lightning Creek) in September but was not detected entering Lightning Creek. The remaining two bull trout were not detected in 2008 after detection at the Dover receiving stations. This report details the progress by work element in the 2008 statement of work, including data analyses of fish movements, and expands on the information reported in the quarterly Pisces status reports.

  10. Thymocyte plasma membrane of the rainbow trout, Salmo gairdneri: Associated immunoglobulin and heteroantigens

    Science.gov (United States)

    Warr, G.W.; DeLuca, D.; Anderson, D.P.

    1983-01-01

    1. Thymic lymphocytes of the rainbow trout, S. gairdneri were disrupted and a plasma membrane containing fraction isolated by differential and buoyant density centrifugation.2. Radioiodine introduced into the membrane by the lactoperoxidase catalyzed reaction and immunoglobulin (identified by radioimmunoassay with monoclonal antibody) both copurified in the plasma membrane fraction.3. Rabbit antibody raised to the plasma membrane fraction showed a strong reaction with trout lymphocytes in immunofluorescence, was mitogenic for trout lymphocytes, and recognized lymphocyte membrane heteroantigens of molecular weight > 70,000 in the thymus and 45,000–95,000 in the head kidney.

  11. Identifying potential virulence determinants in viral haemorrhagic septicaemia virus (VHSV) for rainbow trout

    DEFF Research Database (Denmark)

    Campbell, Scott; Collet, Bertrand; Einer-Jensen, Katja

    2009-01-01

    We identified viral haemorrhagic septicaemia virus (VHSV) isolates classified within Genotype Ib which are genetically similar (>99.4% glycoprotein amino acid identity) yet, based on their isolation history, were suspected to differ in virulence in juvenile rainbow trout. The virulence...... of an isolate recovered in 2000 from a viral haemorrhagic septicaemia disease episode in a marine rainbow trout farm in Sweden (SE-SVA-1033) was evaluated in juvenile rainbow trout via intraperitoneal injection and immersion challenge alongside 3 isolates recovered from wild-caught marine fish (DK-4p37, DK-5e59...

  12. Toxicity of Microcystis aeruginosa peptide toxin to yearling rainbow trout (Oncorhynchus mykiss)

    OpenAIRE

    Tencalla, Francesca G.; Dietrich, Daniel R.; Schlatter, Christian

    1994-01-01

    The effects of the blue-green algae (cyanobacterial) toxin microcystin-LR on yearling rainbow trout were studied in a series of intraperitoneal injection tests, gavage trials and exposures to waterborne algae. Concentrations of the microcystin-producing algae Microcystis aeruginosa known to occur during algae blooms (8 16 mg freeze-dried algae/L, i.e. approximately 1 2 × 1011 cells/L) were shown to be non-toxic to trout when present in aquarium water. On the other hand, trout died within 96 h...

  13. Infectious Pancreatic Necrosis (IPN), a New Threat of Cultured Rainbow Trout in Iran

    DEFF Research Database (Denmark)

    Ghasemi, Mohaddes; Olesen, Niels Jørgen; Skall, Helle Frank

    Background: Infectious pancreatic necrosis virus (IPNV), a member of the virus family Birnaviridae, causes an acute, contagious disease with high mortality rate in a number of economically important fi sh species specially salmonids. During April 2009, one Rainbow trout farm, situated in Gilan...... province, north of Iran, reported unusually high losses of reared rainbow trout fry with average weight of 560 mg. same mortality were reported from 4 other farms in fryes under 1 gram weight in 2010. Clinical signs included darkening, exophthalmia, distended abdomen, fecal cast and a spiral swimming...... rainbow trout fry in Iran....

  14. ATP release and extracellular nucleotidase activity in erythrocytes and coronary circulation of rainbow trout

    DEFF Research Database (Denmark)

    Jensen, Frank B; Agnisola, Claudio; Novak, Ivana

    2009-01-01

    The present study tested the hypothesis that rainbow trout erythrocytes release ATP upon deoxygenation, a mechanism that enables mammalian erythrocytes to produce local vasodilation. We also investigated ATP release and ectonucleotidase activity in the coronary circulation of the isolated trout......-perfused coronary circulation, [ATP] increased as the perfusate moved through the vessels in the presence of ARL 67156. When ATP was added to the inflowing saline, most ATP disappeared during passage of the coronary bed when ARL 67156 was absent but not when it was present. We conclude that rainbow trout...

  15. Estrogen receptor mRNA in mineralized tissues of rainbow trout: calcium mobilization by estrogen.

    Science.gov (United States)

    Armour, K J; Lehane, D B; Pakdel, F; Valotaire, Y; Graham, R; Russell, R G; Henderson, I W

    1997-07-07

    RT-PCR was undertaken on total RNA extracts from bone and scales of the rainbow trout, Oncorhynchus mykiss. The rainbow trout estrogen receptor (ER)-specific primers used amplified a single product of expected size from each tissue which, using Southern blotting, strongly hybridized with a 32P-labelled rtER probe under stringent conditions. These data provide the first in vivo evidence of ER mRNA in bone and scale tissues of rainbow trout and suggest that the effects of estrogen observed in this study (increased bone mineral and decreased scale mineral contents, respectively) may be mediated directly through ER.

  16. Wild Estonian and Russian sea trout (Salmo trutta) in Finnish coastal sea trout catches: results of genetic mixed-stock analysis.

    Science.gov (United States)

    Koljonen, Marja-Liisa; Gross, Riho; Koskiniemi, Jarmo

    2014-12-01

    For responsible fisheries management of threatened species, it is essential to know the composition of catches and the extent to which fisheries exploit weak wild populations. The threatened Estonian, Finnish and Russian sea trout populations in the Gulf of Finland are targets of mixed-stock fisheries. The fish may originate from rivers with varying production capacities, from different countries, and they may also have either a wild or hatchery origin. In order to resolve the composition of Finnish coastal sea trout catches, we created a standardized baseline dataset of 15 DNA microsatellite loci for 59 sea trout populations around the Gulf of Finland and tested its resolution for mixed-stock analysis of 1372 captured fish. The baseline dataset provided sufficient resolution for reliable mixture analysis at regional group level, and also for most of the individual rivers stocks. The majority (76-80%) of the total catch originated from Finnish sea trout populations, 6-9% came from Russian and 12-15% from Estonian populations. Nearly all Finnish trout in the catch were of hatchery origin, while the Russian and Estonian trout were mostly of wild origin. The proportion of fish in the Finnish catches that originated from rivers with natural production was at least one fifth (22%, 19-23%). Two different spotting patterns were observed among the captured trout, with a small and sparsely spotted form being markedly more common among individuals of Russian (28%) and Estonian origin (22%) than among fish assigned to a Finnish origin (0.7%). © 2015 The Authors.

  17. Hybridization between Yellowstone cutthroat trout and rainbow trout alters the expression of muscle growth-related genes and their relationships with growth patterns

    Science.gov (United States)

    Ostberg, Carl O.; Chase, Dorothy M.; Hauser, Lorenz

    2015-01-01

    Hybridization creates novel gene combinations that may generate important evolutionary novelty, but may also reduce existing adaptation by interrupting inherent biological processes, such as genotype-environment interactions. Hybridization often causes substantial change in patterns of gene expression, which, in turn, may cause phenotypic change. Rainbow trout (Oncorhynchus mykiss) and cutthroat trout (O. clarkii) produce viable hybrids in the wild, and introgressive hybridization with introduced rainbow trout is a major conservation concern for native cutthroat trout. The two species differ in body shape, which is likely an evolutionary adaptation to their native environments, and their hybrids tend to show intermediate morphology. The characterization of gene expression patterns may provide insights on the genetic basis of hybrid and parental morphologies, as well as on the ecological performance of hybrids in the wild. Here, we evaluated the expression of eight growth-related genes (MSTN-1a, MSTN-1b, MyoD1a, MyoD1b, MRF-4, IGF-1, IGF-2, and CAST-L) and the relationship of these genes with growth traits (length, weight, and condition factor) in six line crosses: both parental species, both reciprocal F1 hybrids, and both first-generation backcrosses (F1 x rainbow trout and F1 x cutthroat trout). Four of these genes were differentially expressed among rainbow, cutthroat, and their hybrids. Transcript abundance was significantly correlated with growth traits across the parent species, but not across hybrids. Our findings suggest that rainbow and cutthroat trout exhibit differences in muscle growth regulation, that transcriptional networks may be modified by hybridization, and that hybridization disrupts intrinsic relationships between gene expression and growth patterns that may be functionally important for phenotypic adaptations.

  18. Hybridization between Yellowstone Cutthroat Trout and Rainbow Trout Alters the Expression of Muscle Growth-Related Genes and Their Relationships with Growth Patterns.

    Directory of Open Access Journals (Sweden)

    Carl O Ostberg

    Full Text Available Hybridization creates novel gene combinations that may generate important evolutionary novelty, but may also reduce existing adaptation by interrupting inherent biological processes, such as genotype-environment interactions. Hybridization often causes substantial change in patterns of gene expression, which, in turn, may cause phenotypic change. Rainbow trout (Oncorhynchus mykiss and cutthroat trout (O. clarkii produce viable hybrids in the wild, and introgressive hybridization with introduced rainbow trout is a major conservation concern for native cutthroat trout. The two species differ in body shape, which is likely an evolutionary adaptation to their native environments, and their hybrids tend to show intermediate morphology. The characterization of gene expression patterns may provide insights on the genetic basis of hybrid and parental morphologies, as well as on the ecological performance of hybrids in the wild. Here, we evaluated the expression of eight growth-related genes (MSTN-1a, MSTN-1b, MyoD1a, MyoD1b, MRF-4, IGF-1, IGF-2, and CAST-L and the relationship of these genes with growth traits (length, weight, and condition factor in six line crosses: both parental species, both reciprocal F1 hybrids, and both first-generation backcrosses (F1 x rainbow trout and F1 x cutthroat trout. Four of these genes were differentially expressed among rainbow, cutthroat, and their hybrids. Transcript abundance was significantly correlated with growth traits across the parent species, but not across hybrids. Our findings suggest that rainbow and cutthroat trout exhibit differences in muscle growth regulation, that transcriptional networks may be modified by hybridization, and that hybridization disrupts intrinsic relationships between gene expression and growth patterns that may be functionally important for phenotypic adaptations.

  19. Hybridization between Yellowstone Cutthroat Trout and Rainbow Trout Alters the Expression of Muscle Growth-Related Genes and Their Relationships with Growth Patterns.

    Science.gov (United States)

    Ostberg, Carl O; Chase, Dorothy M; Hauser, Lorenz

    2015-01-01

    Hybridization creates novel gene combinations that may generate important evolutionary novelty, but may also reduce existing adaptation by interrupting inherent biological processes, such as genotype-environment interactions. Hybridization often causes substantial change in patterns of gene expression, which, in turn, may cause phenotypic change. Rainbow trout (Oncorhynchus mykiss) and cutthroat trout (O. clarkii) produce viable hybrids in the wild, and introgressive hybridization with introduced rainbow trout is a major conservation concern for native cutthroat trout. The two species differ in body shape, which is likely an evolutionary adaptation to their native environments, and their hybrids tend to show intermediate morphology. The characterization of gene expression patterns may provide insights on the genetic basis of hybrid and parental morphologies, as well as on the ecological performance of hybrids in the wild. Here, we evaluated the expression of eight growth-related genes (MSTN-1a, MSTN-1b, MyoD1a, MyoD1b, MRF-4, IGF-1, IGF-2, and CAST-L) and the relationship of these genes with growth traits (length, weight, and condition factor) in six line crosses: both parental species, both reciprocal F1 hybrids, and both first-generation backcrosses (F1 x rainbow trout and F1 x cutthroat trout). Four of these genes were differentially expressed among rainbow, cutthroat, and their hybrids. Transcript abundance was significantly correlated with growth traits across the parent species, but not across hybrids. Our findings suggest that rainbow and cutthroat trout exhibit differences in muscle growth regulation, that transcriptional networks may be modified by hybridization, and that hybridization disrupts intrinsic relationships between gene expression and growth patterns that may be functionally important for phenotypic adaptations.

  20. Estimating the value of a positive change in trout fly-fishing quality in the Rhodes trout fishery, Eastern Cape, South Africa

    Directory of Open Access Journals (Sweden)

    Mario Du Preez

    2010-12-01

    Full Text Available The Rhodes trout fishery, located in the North Eastern Cape, is one of South Africa’s premier fly-fishing destinations. The integrity of the fishery is, however, under threat due to various land-use practices, which could weaken its appeal as a tourist attraction. The aim of this study is to estimate the amount recreational users are willing to pay for a project to improve the trout habitat of waters managed by the Wild Trout Association (WTA in this fishery in order to improve its fish population density by 100 per cent. Data were collected from a biased sample of 96 respondents via a questionnaire during September 2006 to September 2007. The median estimated willingness-to-pay (WTP for the project was R245 per annum per person, and the total WTP was estimated at R171 500 per annum. A valuation function to predict WTP responses was also estimated, and showed that gross annual pre-tax income and the number of visits per annum were positive determinants of WTP. The results of this study show that policy-makers should take heed of the importance trout fly fishers attach to this fishery when declaring trout zones in the upper catchments of South Africa. The aggregate WTP estimation, however, constitutes only a partial analysis of value. A number of other factors and environmental value streams need to be analysed and compared with the value estimates generated by this study if adequate holistic decision-making is to take place with regard to trout stream improvement. More specifically, the aggregate WTP estimated in this study must be viewed as only one input into a comprehensive social cost-benefit analysis to determine the desirability of trout stream improvement for wider society.