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Sample records for a-run steelhead trout

  1. Microsatellite analyses of Alameda Creek Rainbow/Steelhead trout

    USGS Publications Warehouse

    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.

  2. A mathematical model of predator-prey interaction between seal-herring and steelhead trout

    NASA Astrophysics Data System (ADS)

    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.

  3. Coho salmon and steelhead trout of JDSF

    Treesearch

    Peter Cafferata; Karen Walton; Weldon Jones

    1989-01-01

    Spawning and rearing habitat for anadromous fish is the dominant use of Jackson Demonstration State Forest's (JDSF) many miles of streams. Both coho (silver) salmon and steelhead migrate from the ocean up our rivers in the fall and winter to spawn. About 90 miles of the Forest's streams have been classified as habitat for these fish.

  4. Spatial segregation of spawning habitat limits hybridization between sympatric native Steelhead and Coastal Cutthroat Trout

    USGS Publications Warehouse

    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.

  5. "Investigations of salmon and steelhead trout downstream migrations in Caspar Creek and Little River, Mendocino County, March-July, 1993"

    Treesearch

    Albert Rodriguez; Weldon Jones

    1993-01-01

    Abstract - This annual study has been conducted, since 1987, on two coastal streams, in order to observe the different trend patterns of juvenile out migrations for coho salmon and steelhead-trout, figure 1. Analysis of the 1993 trapping season indicates, at Little River, a decrease of steelhead-trout yearlings but an increase in coho ""y+"". Coho...

  6. Emergence of MD type infectious hematopoietic necrosis virus in Washington State coastal steelhead trout

    USGS Publications Warehouse

    Breyta, Rachel; Jones, Amelia; Stewart, Bruce; Brunson, Ray; Thomas, Joan; Kerwin, John; Bertolini, Jim; Mumford, Sonia; Patterson, Chris; Kurath, Gael

    2013-01-01

    Infectious hematopoietic necrosis virus (IHNV) occurs in North America as 3 major phylogenetic groups designated U, M, and L. In coastal Washington State, IHNV has historically consisted of U genogroup viruses found predominantly in sockeye salmon Oncorhynchus nerka. M genogroup IHNV, which has host-specific virulence for rainbow and steelhead trout O. mykiss, was detected only once in coastal Washington prior to 2007, in an epidemic among juvenile steelhead trout in 1997. Beginning in 2007 and continuing through 2011, there were 8 IHNV epidemics in juvenile steelhead trout, involving 7 different fish culture facilities in 4 separate watersheds. During the same time period, IHNV was also detected in asymptomatic adult steelhead trout from 6 coastal watersheds. Genetic typing of 283 recent virus isolates from coastal Washington revealed that the great majority were in the M genogroup of IHNV and that there were 2 distinct waves of viral emergence between the years 2007 and 2011. IHNV type mG110M was dominant in coastal steelhead trout during 2007 to 2009, and type mG139M was dominant between 2010 and 2011. Phylogenetic analysis of viral isolates indicated that all coastal M genogroup viruses detected in 1997 and 2007 to 2011 were part of the MD subgroup and that several novel genetic variants related to the dominant types arose in the coastal sites. Comparison of spatial and temporal incidence of coastal MD viruses with that of the rest of the Pacific Northwest indicated that the likely source of the emergent viruses was Columbia River Basin steelhead trout

  7. Seasonal habitat use of brook trout and juvenile steelhead in a Lake Ontario tributary

    USGS Publications Warehouse

    Johnson, James H.; Abbett, Ross; Chalupnicki, Marc A.; Verdoliva, Francis

    2016-01-01

    Brook trout (Salvelinus fontinalis) are generally restricted to headwaters in New York tributaries of Lake Ontario. In only a few streams are brook trout abundant in lower stream reaches that are accessible to adult Pacific salmonids migrating from the lake. Consequently, because of the rarity of native brook trout populations in these lower stream reaches it is important to understand how they use stream habitat in sympatry with juvenile Pacific salmonids which are now naturalized in several Lake Ontario tributaries. In this study, we examined the seasonal (spring, summer, and fall) habitat use of brook trout and juvenile steelhead (Oncorhynchus mykiss) in Hart Brook, a tributary of eastern Lake Ontario. We found interspecific, intraspecific, and seasonal variation in habitat use. Subyearling steelhead were associated with faster water velocities than subyearling brook trout and, overall, had the least habitat similarity to the other salmonid groups examined. Overyearling brook trout and yearling steelhead exhibited the greatest degree of habitat selection and habitat selection by all four salmonid groups was greatest in summer. The availability of pool habitat for overyearling salmonids may pose the largest impediment to these species in Hart Brook.

  8. STABLE ISOTOPE SIGNATURES OF MUCUS OF STEELHEAD TROUT IN A CONTROLLED DIET SWITCH EXPERIMENT

    EPA Science Inventory

    Our work has shown that fish mucus can serve as a very rapid indicator of diet switching in fish. We performed diet switching studies of steelhead trout in a controlled hatchery setting using specially formulated low delta 15N signature and high delta 15N signature diets. To ou...

  9. Response of steelhead/rainbow trout (Oncorhynchus mykiss) populations to debris flows

    Treesearch

    Jason L. White; Bret C. Harvey

    2017-01-01

    To better understand the effects of debris flows on salmonid populations, we studied juvenile steelhead/rainbow trout (Oncorhynchus mykiss) populations in six streams in the Klamath Mountains of northern California: three affected by debris flows on 01 January 1997 and three that experienced elevated streamflows but no debris flows. We surveyed...

  10. Use of streambed substrate as refuge by steelhead or rainbow trout Oncorhynchus mykiss during simulated freshets

    Treesearch

    F. K. Ligon; Rodney Nakamoto; Bret Harvey; P. F. Baker

    2016-01-01

    A flume was used to estimate the carrying capacity of streambed substrates for juvenile steelhead or rainbow trout Oncorhynchus mykiss seeking refuge from simulated freshets. The simulated freshets had mean water column velocities of c. 1·1 m s−1. The number of O. mykiss finding cover...

  11. Should I stay or should I go? Understanding the shapeshifting rainbow trout/steelhead

    Treesearch

    Geoff Koch; Gordon Reeves

    2015-01-01

    Steelhead are the sea-going form of Oncorhynchus mykiss. Rainbow trout,also O. mykiss, remain in freshwater. Each form, or life-history, can produce offspring of the other, but the mechanism for this and potential effects that climate change may have on the species are poorly understood.Forest...

  12. Demographic and phenotypic responses of juvenile steelhead trout to spatial predictability of food resources

    Treesearch

    Matthew R. Sloat; Gordon H. Reeves

    2014-01-01

    We manipulated food inputs among patches within experimental streams to determine how variation in foraging behavior influenced demographic and phenotypic responses of juvenile steelhead trout (Oncorhynchus mykiss) to the spatial predictability of food resources. Demographic responses included compensatory adjustments in fish abundance, mean fish...

  13. Fluvial rainbow trout contribute to the colonization of steelhead (Oncorhynchus mykiss) in a small stream

    USGS Publications Warehouse

    Weigel, Dana E.; Connolly, Patrick J.; Powell, Madison S.

    2013-01-01

    Life history polymorphisms provide ecological and genetic diversity important to the long term persistence of species responding to stochastic environments. Oncorhynchus mykiss have complex and overlapping life history strategies that are also sympatric with hatchery populations. Passive integrated transponder (PIT) tags and parentage analysis were used to identify the life history, origin (hatchery or wild) and reproductive success of migratory rainbow/steelhead for two brood years after barriers were removed from a small stream. The fluvial rainbow trout provided a source of wild genotypes to the colonizing population boosting the number of successful spawners. Significantly more parr offspring were produced by anadromous parents than expected in brood year 2005, whereas significantly more parr offspring were produced by fluvial parents than expected in brood year 2006. Although hatchery steelhead were prevalent in the Methow Basin, they produced only 2 parr and no returning adults in Beaver Creek. On average, individual wild steelhead produced more parr offspring than the fluvial or hatchery groups. Yet, the offspring that returned as adult steelhead were from parents that produced few parr offspring, indicating that high production of parr offspring may not be related to greater returns of adult offspring. These data in combination with other studies of sympatric life histories of O. mykiss indicate that fluvial rainbow trout are important to the conservation and recovery of steelhead and should be included in the management and recovery efforts.

  14. Histological assessment of organs in sexually mature and post-spawning steelhead trout and insights into iteroparity

    USGS Publications Warehouse

    Penney, Zachary L.; Moffitt, Christine M.

    2014-01-01

    Steelhead trout (Oncorhynchus mykiss) are anadromous and iteroparous, but repeat-spawning rates are generally low. Like other anadromous salmonids, steelhead trout fast during freshwater spawning migrations, but little is known about the changes that occur in vital organs and tissues. We hypothesized that fish capable of repeat-spawning would not undergo the same irreversible degeneration and cellular necrosis documented in semelparous salmon. Using Snake River steelhead trout as a model we used histological analysis to assess the cellular architecture in the pyloric stomach, ovary, liver, and spleen in sexually mature and kelt steelhead trout. We observed 38 % of emigrating kelts with food or fecal material in the gastrointestinal tract. Evidence of feeding was more likely in good condition kelts, and feeding was associated with a significant renewal of villi in the pyloric stomach. No vitellogenic oocytes were observed in sections of kelt ovaries, but perinucleolar and early/late stage cortical alveolus oocytes were present suggesting iteroparity was possible. We documented a negative correlation between the quantity of perinucleolar oocytes in ovarian tissues and fork length of kelts suggesting that larger steelhead trout may invest more into a single spawning event. Liver and spleen tissues of both mature and kelt steelhead trout had minimal cellular necroses. Our findings indicate that the physiological processes causing rapid senescence and death in semelparous salmon are not evident in steelhead trout, and recovery begins in fresh water. Future management efforts to increase iteroparity in steelhead trout and Atlantic salmon must consider the physiological processes that influence post-spawning recovery.

  15. Early marine migration patterns of wild coastal cutthroat trout (Oncorhynchus clarki clarki), steelhead trout (Oncorhynchus mykiss), and their hybrids.

    PubMed

    Moore, Megan E; Goetz, Fred A; Van Doornik, Donald M; Tezak, Eugene P; Quinn, Thomas P; Reyes-Tomassini, Jose J; Berejikian, Barry A

    2010-09-20

    Hybridization between coastal cutthroat trout (Oncorhynchus clarki clarki) and steelhead or rainbow trout (Oncorhynchus mykiss) has been documented in several streams along the North American west coast. The two species occupy similar freshwater habitats but the anadromous forms differ greatly in the duration of marine residence and migration patterns at sea. Intermediate morphological, physiological, and performance traits have been reported for hybrids but little information has been published comparing the behavior of hybrids to the pure species. This study used acoustic telemetry to record the movements of 52 cutthroat, 42 steelhead x cutthroat hybrids, and 89 steelhead smolts, all wild, that migrated from Big Beef Creek into Hood Canal (Puget Sound, Washington). Various spatial and temporal metrics were used to compare the behavior of the pure species to their hybrids. Median hybrid residence time, estuary time, and tortuosity values were intermediate compared to the pure species. The median total track distance was greater for hybrids than for either cutthroat or steelhead. At the end of each track, most steelhead (80%) were located near or north of the Hood Canal, as expected for this seaward migrating species, whereas most cutthroat (89%) were within 8 kilometers of the estuary. Most hybrids (70%) were detected leaving Hood Canal, though a substantial percentage (20%) remained near the Big Beef Creek estuary. More hybrids (7.5%) than pure cutthroat (4.5%) or steelhead (0.0%) were last detected in the southern reaches of Hood Canal. Given the similarity in freshwater ecology between the species, differences in marine ecology may play an important role in maintaining species integrity in areas of sympatry.

  16. Stress of formalin treatment in juvenile spring chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Salmo gairdneri)

    USGS Publications Warehouse

    Wedemeyer, Gary; Yasutake, W.T.

    1973-01-01

    The physiological stress of 200 ppm formalin treatments at 10 C is more severe in the juvenile steelhead trout (Salmo gairdneri) than in the spring chinook salmon (Oncorhynchus tshawytscha). In the steelhead, a marked hypochloremia follows a 1-hr treatment and recovery requires about 24 hr. During longer treatments, hypercholesterolemia together with reduced regulatory precision, hypercortisolemia, alkaline reserve depletion, and hypocapnia unaccompanied by a fall in blood pH occur — suggestive of compensated respiratory alkalosis. In the spring chinook, hypochloremia and reduced plasma cholesterol regulatory precision are the significant treatment side effects but recovery requires only a few hours.Formalin treatments also cause epithelial separation, hypertrophy, and necrosis in the gills of both fishes but again, consistent with the physiological dysfunctions, these are more severe in the steelhead.

  17. Genetic variation underlying resistance to infectious hematopoietic necrosis virus in a steelhead trout (Oncorhynchus mykiss) population

    USGS Publications Warehouse

    Brieuc, Marine S. O.; Purcell, Maureen K.; Palmer, Alexander D.; Naish, Kerry A.

    2015-01-01

    Understanding the mechanisms of host resistance to pathogens will allow insights into the response of wild populations to the emergence of new pathogens. Infectious hematopoietic necrosis virus (IHNV) is endemic to the Pacific Northwest and infectious to Pacific salmon and trout (Oncorhynchus spp.). Emergence of the M genogroup of IHNV in steelhead trout O. mykiss in the coastal streams of Washington State, between 2007 and 2011, was geographically heterogeneous. Differences in host resistance due to genetic change were hypothesized to be a factor influencing the IHNV emergence patterns. For example, juvenile steelhead trout losses at the Quinault National Fish Hatchery (QNFH) were much lower than those at a nearby facility that cultures a stock originally derived from the same source population. Using a classical quantitative genetic approach, we determined the potential for the QNFH steelhead trout population to respond to selection caused by the pathogen, by estimating the heritability for 2 traits indicative of IHNV resistance, mortality (h2 = 0.377 (0.226 - 0.550)) and days to death (h2 = 0.093 (0.018 - 0.203)). These results confirm that there is a genetic basis for resistance and that this population has the potential to adapt to IHNV. Additionally, genetic correlation between days to death and fish length suggests a correlated response in these traits to selection. Reduction of genetic variation, as well as the presence or absence of resistant alleles, could affect the ability of populations to adapt to the pathogen. Identification of the genetic basis for IHNV resistance could allow the assessment of the susceptibility of other steelhead populations.

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

    SciTech Connect

    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 amongmore » 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.« less

  19. Some physiological aspects of sublethal heat stress in the juvenile steelhead trout (Salmo gairdneri) and coho salmon (Oncorhynchus kisutch)

    USGS Publications Warehouse

    Wedemeyer, Gary

    1973-01-01

    A rapid (3 min) but sublethal temperature increase from 10 to 20 imposed a greater stress on juvenile coho salmon (Oncorhynchus kisutch) than on juvenile steelhead trout (Salmo gairdneri). Both species suffered hyperglycemia, hypocholesterolemia, increased blood hemoglobin, and decreased blood sugar regulatory precision, but the steelhead recovered more quickly. Acid–base equilibrium was essentially unaffected, and only the coho suffered any significant interrenal vitamin C depletion. Vitamin C normalization required about 24 hr.

  20. Identification of steelhead and resident rainbow trout progeny in the Deschutes River, Oregon, revealed with otolith microchemistry

    USGS Publications Warehouse

    Zimmerman, C.E.; Reeves, G.H.

    2002-01-01

    Comparisons of strontium:calcium (Sr:Ca) ratios in otolith primordia and freshwater growth regions were used to identify the progeny of steelhead Oncorhynchus mykiss (anadromous rainbow trout) and resident rainbow trout in the Deschutes River, Oregon. We cultured progeny of known adult steelhead and resident rainbow trout to confirm the relationship between Sr:Ca ratios in otolith primordia and the life history of the maternal parent. The mean (??SD) Sr:Ca ratio was significantly higher in the otolith primordia of the progeny of steelhead (0.001461 ?? 0.00029; n = 100) than in those of the progeny of resident rainbow trout (0.000829 ?? 0.000012; n = 100). We used comparisons of Sr:Ca ratios in the primordia and first-summer growth regions of otoliths to determine the maternal origin of unknown O. mykiss juveniles (n = 272) collected from rearing habitats within the main-stem Deschutes River and tributary rearing habitats and thus to ascertain the relative proportion of each life history morph in each rearing habitat. Resident rainbow trout fry dominated the bi-monthly samples collected from main-stem rearing habitats between May and November 1995. Steelhead fry dominated samples collected from below waterfalls on two tributaries in 1996 and 1998.

  1. The effect of diet on dorsal fin erosion in steelhead trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Lellis, W.A.; Barrows, F.T.

    1997-01-01

    A 2 X 2 factorial experiment of diet type (krill vs. fish meal) and steroid supplementation (0 vs. 30 ??g 17??-methyltestosterone kg-1) was conducted to determine the effects on dorsal fin erosion in steelhead trout. Triplicate tanks of 250 fry were fed one of the four diets at a rate calculated to produce 115 g fish in 34 weeks. Fish were transferred to larger tanks when mean density index reached 0.40. Dorsal fin index (DFI, measured as mean dorsal fin height X 100/total fish length) was greater (P < 0.001) among fish fed krill-based diets than for fish fed fish-based diets at weeks 12, 22, and 34 of the trial. Added testosterone decreased (p = 0.04) DFI among fish fed the krill diet at week 12 but otherwise had no effect on fin condition. Addition of testosterone to either diet type decreased (P = 0.02) critical thermal maximum, which is a measure of fish resistance to thermal stress. The results suggest that diet composition can influence the rate of dorsal fin erosion in steelhead trout through a metabolic, behavioral, or combined change.

  2. Effects of pyrethroid insecticides in urban runoff on Chinook salmon, steelhead trout, and their invertebrate prey.

    PubMed

    Weston, Donald P; Schlenk, Daniel; Riar, Navneet; Lydy, Michael J; Brooks, Marjorie L

    2015-03-01

    Pyrethroid insecticides can affect salmonids either indirectly through toxicity to their prey or directly by toxicity to the fish themselves. In support of a study on pyrethroid impacts to Chinook salmon and steelhead trout in the American River (Sacramento, California, USA), 96-h median effective concentration (EC50) and median lethal concentration (LC50) values for the pyrethroid bifenthrin were determined for taxa not traditionally used for toxicity testing but of interest as salmonid prey, including a chironomid, caddisflies, mayflies, and stoneflies. A laboratory was constructed on the banks of the American River to expose macroinvertebrates, Chinook salmon, and steelhead trout to flow-through river water containing urban runoff during storm events. Bifenthrin from urban runoff was found in river water following 5 rain events, reaching 14.6 ng/L. Mortality to the exposed salmonids was not observed, and sublethal effects were not seen in vitellogenin or sex steroid levels. Indirect effects via toxicity to salmonid prey are possible. Mortality to Hyalella azteca, a potential prey, was observed in every event tested, and peak bifenthrin concentrations were comparable to the 96-h EC50 of the caddisfly, Hydropsyche sp., the most important prey species on a biomass basis for American River Chinook salmon. The other invertebrates tested had EC50s exceeding bifenthrin concentrations seen in the American River, though could potentially be at risk at concentrations previously reported in smaller urban tributaries. Environ Toxicol Chem 2015;34:649-657. © 2014 SETAC. © 2014 SETAC.

  3. A comparison of susceptibility to Myxobolus cerebralis among strains of rainbow trout and steelhead in field and laboratory trials

    USGS Publications Warehouse

    Densmore, Christine L.; Blazer, V.S.; Cartwright, Deborah D.; Schill, W.B.; Schachte, J.H.; Petrie, C.J.; Batur, M.V.; Waldrop, T.B.; Mack, A.; Pooler, P.S.

    2001-01-01

    Three strains of rainbow trout and steelhead Oncorhynchus mykiss were evaluated for the presence of whirling disease in field and laboratory trials. In the field exposures, fingerling Salmon River steelhead and Cayuga Lake and Randolph strains of rainbow trout were placed in wire cages in an earthen, stream-fed pond in New York State that was known to harbor Myxobolus cerebralis. Control fish were held at another hatchery that was free of whirling disease. In the controlled trials at the National Fish Health Research Laboratory, fingerling steelhead and Cayuga Lake and Mount Lassen rainbow trout were exposed to triactinomyxons at low (200 triactinomyxons/fish) or high (2,000 triactinomyxons/fish) levels for 2 h. Controls of each group were sham-exposed. Following an incubation period of 154 d for laboratory trials and 180 d for field trials, cranial tissue samples were taken for spore enumeration (field and laboratory trials) and histological analyses (laboratory only). Clinical signs of disease, including whirling behavior, blacktail, and skeletal deformities, were recorded for each fish in the laboratory trial at the terminal sampling. No clinical evidence of disease was noted among fish in the field trials. Clinical signs were noted among all strains in the laboratory trials at both exposure levels, and these signs were consistently greatest for the Mount Lassen strain. Whirling and skeletal deformities were more evident in the steelhead than in the Cayuga Lake rainbow trout; blacktail was more common in the Cayuga Lake fish. In both field and laboratory trials, spore counts were significantly higher for Cayuga Lake rainbow trout than in steelhead. In laboratory trials, moderate to marked cranial tissue lesions predominated in all three strains.

  4. Successful mitigation of viral disease based on a delayed exposure rearing strategy at a large-scale steelhead trout conservation hatchery

    USGS Publications Warehouse

    Breyta, R.; Samson, Corie; Blair, Marilyn; Black, Allison; Kurath, Gael

    2015-01-01

    In 2009, the largest steelhead trout conservation hatchery in the state of Idaho, Dworshak National Fish Hatchery (NFH), lost over 50% of the juvenile steelhead trout (Oncorhynchus mykiss) population being reared for release. The causative agent of this high mortality was the viral pathogen infectious hematopoietic necrosis virus (IHNV). This was neither the first nor the worst epidemic of IHNV to occur at the hatchery, but it was the worst in over a decade. Genetic analysis of IHNV isolates taken from juveniles suffering epidemic IHN disease in 2009 revealed that the virus was of the M group of IHNV viruses, known to have high virulence for trout. The water supply for steelhead trout rearing at Dworshak NFH is untreated water taken directly from the Clearwater River. Further genetic analysis of IHNV isolates from adults spawned in 2009 indicated that adult steelhead trout in the river (in the hatchery water supply) were the most probable transmission source for the epidemic IHN disease in the juvenile fish. Previously, Dworshak NFH had been able to gain access to reservoir water from behind the Dworshak Dam for nursery egg incubation and the earliest stage of fry rearing, which nearly eliminated incidence of IHN disease in that stage of rearing. Additionally, the nearby Clearwater State Fish Hatchery (SFH), which operates entirely with reservoir water, has never had a case of IHN disease in juvenile steelhead trout. Therefore, staff at Dworshak NFH sought and obtained access to a limited supply of reservoir water for the first few months of outdoor rearing of juvenile steelhead trout, beginning in 2010. This strategy delayed the exposure of juvenile steelhead trout to river water for several months. The effects of this program change were: drastic reduction in IHN disease in juvenile steelhead trout; interruption in the transmission of highly virulent M group IHNV from adult steelhead trout; no interruption in the transmission of low virulent U group IHNV from

  5. Effect of short-term decrease in water temperature on body temperature and involvement of testosterone in steelhead and rainbow trout, Oncorhynchus mykiss.

    PubMed

    Miura, Go; Munakata, Arimune; Yada, Takashi; Schreck, Carl B; Noakes, David L G; Matsuda, Hiroyuki

    2013-09-01

    The Pacific salmonid species Oncorhynchus mykiss is separated into a migratory form (steelhead trout) and a non-migratory form (rainbow trout). A decrease in water temperature is likely a cue triggering downstream behavior in the migratory form, and testosterone inhibits onset of this behavior. To elucidate differences in sensitivity to water temperature decreases between the migratory and non-migratory forms and effect of testosterone on the sensitivity, we examined two experiments. In experiment 1, we compared changes in body temperature during a short-term decrease in water temperature between both live and dead steelhead and rainbow trout. In experiment 2, we investigated effects of testosterone on body temperature decrease in steelhead trout. Water temperature was decreased by 3°C in 30min. The body temperature of the steelhead decreased faster than that of the rainbow trout. In contrast, there was no significant difference in the decrease in body temperature between dead steelhead and rainbow trout specimens. The body temperature of the testosterone-treated steelhead trout decreased more slowly than that of control fish. Our results suggest that the migratory form is more sensitive to decreases in water temperature than the non-migratory form. Moreover, testosterone might play an inhibitory role in sensitivity to such decreases. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Genetic differences in growth and survival of juvenile hatchery and wild steelhead trout, Salmo gairdneri

    USGS Publications Warehouse

    Reisenbichler, R.R.; McIntyre, J.D.

    1997-01-01

    Relative growth and survival of offspring from matings of hatchery and wild Deschutes River (Oregon) summer steelhead trout, Salmo gairdneri, were measured to determine if hatchery fish differ genetically from wild fish in traits that can affect the stock–recruitment relationship of wild populations. Sections of four natural streams and a hatchery pond were each stocked with genetically marked (lactate dehydrogenase genotypes) eyed eggs or unfed swim-up fry from each of three matings: hatchery × hatchery (HH), hatchery × wild (HW), and wild × wild (WW). In streams, WW fish had the highest survival and HW fish the highest growth rates when significant differences were found; in the hatchery pond, HH fish had the highest survival and growth rates. The hatchery fish were genetically different from wild fish and when they interbreed with wild fish may reduce the number of smolts produced. Hatchery procedures can be modified to reduce the genetic differences between hatchery and wild fish.

  7. Genetic Architecture of Migration-Related Traits in Rainbow and Steelhead Trout, Oncorhynchus mykiss

    PubMed Central

    Hecht, Benjamin C.; Thrower, Frank P.; Hale, Matthew C.; Miller, Michael R.; Nichols, Krista M.

    2012-01-01

    Although migration plays a critical role in the evolution and diversification of species, relatively little is known of the genetic architecture underlying this life history in any species. Rainbow and steelhead trout (Oncorhynchus mykiss) naturally segregate for both resident and migratory life-history types, respectively, as do other members of the salmonid family of fishes. Using an experimental cross derived from wild resident rainbow and wild migratory steelhead trout from Southeast Alaska and high throughput restriction-site associated DNA (RAD) tag sequencing, we perform a quantitative trait locus (QTL) analysis to identify the number, position, and relative contribution of genetic effects on a suite of 27 physiological and morphological traits associated with the migratory life history in this species. In total, 37 QTL are localized to 19 unique QTL positions, explaining 4–13.63% of the variation for 19 of the 27 migration-related traits measured. Two chromosomal positions, one on chromosome Omy12 and the other on Omy14 each harbor 7 QTL for migration-related traits, suggesting that these regions could harbor master genetic controls for the migratory life-history tactic in this species. Another QTL region on Omy5 has been implicated in several studies of adaptive life histories within this species and could represent another important locus underlying the migratory life history. We also evaluate whether loci identified in this out-crossed QTL study colocalize to genomic positions previously identified for associations with migration-related traits in a doubled haploid mapping family. PMID:22973549

  8. Molecular characterization of a novel orthomyxovirus from rainbow and steelhead trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Batts, William N.; LaPatra, Scott E.; Katona, Ryan; Leis, Eric; Fei Fan Ng, Terry; Bruieuc, Marine S.O.; Breyta, Rachel; Purcell, Maureen; Waltzek, Thomas B.; Delwart, Eric; Winton, James

    2017-01-01

    A novel virus, rainbow trout orthomyxovirus (RbtOV), was isolated in 1997 and again in 2000 from commercially-reared rainbow trout (Oncorhynchus mykiss) in Idaho, USA. The virus grew optimally in the CHSE-214 cell line at 15°C producing a diffuse cytopathic effect; however, juvenile rainbow trout exposed to cell culture-grown virus showed no mortality or gross pathology. Electron microscopy of preparations from infected cell cultures revealed the presence of typical orthomyxovirus particles. The complete genome of RbtOV is comprised of eight linear segments of single-stranded, negative-sense RNA having highly conserved 5′ and 3′-terminal nucleotide sequences. Another virus isolated in 2014 from steelhead trout (also O. mykiss) in Wisconsin, USA, and designated SttOV was found to have eight genome segments with high amino acid sequence identities (89–99%) to the corresponding genes of RbtOV, suggesting these new viruses are isolates of the same virus species and may be more widespread than currently realized. The new isolates had the same genome segment order and the closest pairwise amino acid sequence identities of 16–42% with Infectious salmon anemia virus (ISAV), the type species and currently only member of the genus Isavirus in the family Orthomyxoviridae. However, pairwise comparisons of the predicted amino acid sequences of the 10 RbtOV and SttOV proteins with orthologs from representatives of the established orthomyxoviral genera and a phylogenetic analysis using the PB1 protein showed that while RbtOV and SttOV clustered most closely with ISAV, they diverged sufficiently to merit consideration as representatives of a novel genus. A set of PCR primers was designed using conserved regions of the PB1 gene to produce amplicons that may be sequenced for identification of similar fish orthomyxoviruses in the future.

  9. Molecular characterization of a novel orthomyxovirus from rainbow and steelhead trout (Oncorhynchus mykiss).

    PubMed

    Batts, William N; LaPatra, Scott E; Katona, Ryan; Leis, Eric; Ng, Terry Fei Fan; Brieuc, Marine S O; Breyta, Rachel B; Purcell, Maureen K; Conway, Carla M; Waltzek, Thomas B; Delwart, Eric; Winton, James R

    2017-02-15

    A novel virus, rainbow trout orthomyxovirus (RbtOV), was isolated in 1997 and again in 2000 from commercially-reared rainbow trout (Oncorhynchus mykiss) in Idaho, USA. The virus grew optimally in the CHSE-214 cell line at 15°C producing a diffuse cytopathic effect; however, juvenile rainbow trout exposed to cell culture-grown virus showed no mortality or gross pathology. Electron microscopy of preparations from infected cell cultures revealed the presence of typical orthomyxovirus particles. The complete genome of RbtOV is comprised of eight linear segments of single-stranded, negative-sense RNA having highly conserved 5' and 3'-terminal nucleotide sequences. Another virus isolated in 2014 from steelhead trout (also O. mykiss) in Wisconsin, USA, and designated SttOV was found to have eight genome segments with high amino acid sequence identities (89-99%) to the corresponding genes of RbtOV, suggesting these new viruses are isolates of the same virus species and may be more widespread than currently realized. The new isolates had the same genome segment order and the closest pairwise amino acid sequence identities of 16-42% with Infectious salmon anemia virus (ISAV), the type species and currently only member of the genus Isavirus in the family Orthomyxoviridae. However, pairwise comparisons of the predicted amino acid sequences of the 10 RbtOV and SttOV proteins with orthologs from representatives of the established orthomyxoviral genera and a phylogenetic analysis using the PB1 protein showed that while RbtOV and SttOV clustered most closely with ISAV, they diverged sufficiently to merit consideration as representatives of a novel genus. A set of PCR primers was designed using conserved regions of the PB1 gene to produce amplicons that may be sequenced for identification of similar fish orthomyxoviruses in the future. Published by Elsevier B.V.

  10. Inhibition of salt water survival and Na-K-ATPase elevation in steelhead trout (Salmo gairdneri) by moderate water temperatures

    USGS Publications Warehouse

    Adams, B.L.; Zaugg, W.S.; McLain, L. R.

    1975-01-01

    The steelhead trout metamorphosis from a freshwater parr to a sea water-tolerant smolt possessing the migration tendency was evaluated at six different growth temperatures ranging from 6 to 15 C during January through July. The highest temperature where a transformation was indicated was 11.3 C. By April fish reared at 6 C had elevated ATPase levels typical of smolts or migratory animals and showed 92% survival in sea water. Ten and 11.3 C-reared fish showed a short-lived elevation in ATPase in mid-April alone concurrently with 100% sea water survival at that time. Only in 6 C-reared animals did the salt water survival ability continue into May. High ATPase levels likewise were prolonged into May and June only in the 6 C-reared group. The data indicate that metamorphosis (and therefore successful migration) of juvenile steelhead trout is directly controlled by water temperature.

  11. Individual condition and stream temperature influence early maturation of rainbow and steelhead trout, ncorhynchus mykiss

    USGS Publications Warehouse

    McMillan, John R.; Dunham, Jason B.; Reeves, Gordon H.; Mills, Justin S.; Jordan, Chris E.

    2012-01-01

    Alternative male phenotypes in salmonine fishes arise from individuals that mature as larger and older anadromous marine-migrants or as smaller and younger freshwater residents. To better understand the processes influencing the expression of these phenotypes we examined the influences of growth in length (fork length) and whole body lipid content in rainbow trout (Oncorhynchus mykiss). Fish were sampled from the John Day River basin in northeast Oregon where both anadromous ("steelhead") and freshwater resident rainbow trout coexist. Larger males with higher lipid levels had a greater probability of maturing as a resident at age-1+. Among males, 38% were maturing overall, and the odds ratios of the logistic model indicated that the probability of a male maturing early as a resident at age-1+ increased 49% (95% confidence interval (CI) = 23-81%) for every 5 mm increase in length and 33% (95% CI = 10-61%) for every 0.5% increase in whole body lipid content. There was an inverse association between individual condition and water temperature as growth was greater in warmer streams while whole body lipid content was higher in cooler streams. Our results support predictions from life history theory and further suggest that relationships between individual condition, maturation, and environmental variables (e.g., water temperature) are shaped by complex developmental and evolutionary influences.

  12. Prevention and treatment of Nitrite toxicity in juvenile steelhead trout (Salmo gairdneri)

    USGS Publications Warehouse

    Wedemeyer, Gary A.; Yasutake, W.T.

    1978-01-01

    The efficacy of mineral salts, pH, and tetramethylthianine (methylene blue) treatment in reducing the acute toxicity of nitrite to fingerling steelhead trout (Salmo gairdneri) was determined using a static bioassay system at 10 °C. The acute toxicity (96-h LC50) was reduced by a factor of about 24 for 5-g steelhead and 13 for 10-g fish when the total water hardness was increased from 25 to 300 mg/L (as CaCO3). NaCl or CaCl2 additions (0–200 mg/L) reduced toxicity by a factor of up to 3 for NaCl and 50 for CaCl2. Increasing the pH from 6.0 to 8.0 decreased toxicity by a factor of about 8 for the smaller and 3 for the larger fish. Methylene blue at 0.1 or 1.0 mg/L was effective in decreasing acute toxicity. For alleviating methemoglobinemia, removing the fish to freshwater for 48 h was about as effective as 1.0 mg/L methylene blue. Chronic exposure in soft water to 0.03 mg/L NO2-N for 6 mo caused no significant growth reduction, gill histological changes, hematological dyscrasias, or impaired ability of the smolts to adapt to 30‰ seawater and grow for an additional 2 mo. Key words: nitrite, toxicity, fish, methylene blue, pH, salts, acute toxicity, chronic toxicity

  13. Population Structure of Columbia River Basin Chinook Salmon and Steelhead Trout, Technical Report 2001.

    SciTech Connect

    Brannon, E.L.; National Science Foundation

    2002-08-01

    The population structure of chinook salmon and steelhead trout is presented as an assimilation of the life history forms that have evolved in synchrony with diverse and complex environments over their Pacific range. As poikilotherms, temperature is described as the overwhelming environmental influence that determines what life history options occur and where they are distributed. The different populations represent ecological types referred to as spring-, summer-, fall, and winter-run segments, as well as stream- and ocean-type, or stream- and ocean-maturing life history forms. However, they are more correctly described as a continuum of forms that fall along a temporal clinemore » related to incubation and rearing temperatures that determine spawn timing and juvenile residence patterns. Once new habitats are colonized, members of the founding populations spread through adaptive evolution to assume complementary life history strategies. The related population units are collectively referred to as a metapopulation, and members most closely associated within common temporal and geographic boundaries are designated as first-order metapopulations. Population structure of chinook salmon and steelhead in the Columbia Basin, therefore, is the reflection of the genetic composition of the founding source or sources within the respective region, shaped by the environment, principally temperature, that defines life history evolutionary strategy to maximize fitness under the conditions delineated. The complexity of structure rests with the diversity of opportunities over the elevations that exist within the Basin. Consistent with natural selection, rather than simply attempting to preserve populations, the challenge is to provide opportunities to expand their range to new or restored habitat that can accommodate genetic adaptation as directional environmental changes are elaborated. Artificial propagation can have a critical role in this process, and the emphasis must be

  14. Differential susceptibility in steelhead trout populations to an emergent MD strain of infectious hematopoietic necrosis virus

    USGS Publications Warehouse

    Breyta, R.; Jones, Amelia; Kurath, Gael

    2014-01-01

    A significant emergence of trout-adapted MD subgroup infectious hematopoietic necrosis virus (IHNV) began in the coastal region of Washington State, USA, in 2007. This emergence event lasted until 2011 and caused both asymptomatic adult fish infection and symptomatic epidemic disease and mortality in juvenile fish. Incidence of virus during this emergence demonstrated a heterogeneous distribution among rivers of the coastal region, leaving fish populations of some rivers apparently untouched while others suffered significant and recurrent infection and mortality (Breyta et. al. 2013; Dis Aquat Org 104:179-195). In this study, we examined the possible contribution of variations in susceptibility of fish populations, age-related resistance, and virus virulence to the observed landscape heterogeneity. We found that the most significant variable was host susceptibility: by controlled experimental challenge studies steelhead trout populations with no history of IHNV infection were 1 to 3 orders of magnitude more sensitive than a fish population with a long history of IHNV infection. In addition, 2 fish populations from the same river, which descended relatively recently from a common ancestral population, demonstrated 1 to 2 orders of magnitude difference in susceptibility. Fish age-related development of resistance was most evident in the more susceptible of 2 related fish populations. Finally, the strain of virus involved in the 2007 coastal Washington emergence had high virulence but was within the range of other known M group viruses tested. These results suggest that one major driver of landscape heterogeneity in the 2007 coastal Washington IHNV emergence was variation in fish population susceptibility and that this trait may have a heritable component.

  15. Use of streambed substrate as refuge by steelhead or rainbow trout Oncorhynchus mykiss during simulated freshets.

    PubMed

    Ligon, F K; Nakamoto, R J; Harvey, B C; Baker, P F

    2016-04-01

    A flume was used to estimate the carrying capacity of streambed substrates for juvenile steelhead or rainbow trout Oncorhynchus mykiss seeking refuge from simulated freshets. The simulated freshets had mean water column velocities of c. 1·1 m s(-1). The number of O. mykiss finding cover within the interstices of the substrate was documented for different substrate sizes and levels of embeddedness. The availability of suitable refuges determined the carrying capacity of the substrate for O. mykiss. For the size of the O. mykiss tested [mean ± s.d. fork length (L(F)) = 122 ± 12.6 mm], the number of interstices with depths ≥200 mm measured with a 14.0 mm diameter flexible plastic tube was the best predictor of the number of O. mykiss able to find cover (r(2)  = 0.75). Oncorhynchus mykiss seeking refuge from freshets may need deeper interstices than those seeking concealment at autumn or winter base flows. The availability of interstices suitable as refuge from high flows may determine autumn and winter carrying capacity. © 2016 The Fisheries Society of the British Isles.

  16. Rapid discovery of SNPs differentiating hatchery steelhead trout from ESA-listed wild steelhead trout using a 57K SNP array

    USDA-ARS?s Scientific Manuscript database

    Natural-origin steelhead in the Pacific Northwest USA are threatened by a number of factors including habitat destruction, disease, decline in marine survival and a potential erosion of genetic viability due to introgression from hatchery strains. The major goal of this study was to use a recently ...

  17. Transmission routes maintaining a viral pathogen of steelhead trout within a complex multi-host assemblage

    USGS Publications Warehouse

    Breyta, Rachel; Brito, Ilana L.; Ferguson, Paige; Kurath, Gael; Naish, Kerry A.; Purcell, Maureen; Wargo, Andrew R.; LaDeau, Shannon L.

    2017-01-01

    This is the first comprehensive region wide, spatially explicit epidemiologic analysis of surveillance data of the aquatic viral pathogen infectious hematopoietic necrosis virus (IHNV) infecting native salmonid fish. The pathogen has been documented in the freshwater ecosystem of the Pacific Northwest of North America since the 1950s, and the current report describes the disease ecology of IHNV during 2000–2012. Prevalence of IHNV infection in monitored salmonid host cohorts ranged from 8% to 30%, with the highest levels observed in juvenile steelhead trout. The spatial distribution of all IHNV-infected cohorts was concentrated in two sub-regions of the study area, where historic burden of the viral disease has been high. During the study period, prevalence levels fluctuated with a temporal peak in 2002. Virologic and genetic surveillance data were analyzed for evidence of three separate but not mutually exclusive transmission routes hypothesized to be maintaining IHNV in the freshwater ecosystem. Transmission between year classes of juvenile fish at individual sites (route 1) was supported at varying levels of certainty in 10%–55% of candidate cases, transmission between neighboring juvenile cohorts (route 2) was supported in 31%–78% of candidate cases, and transmission from adult fish returning to the same site as an infected juvenile cohort was supported in 26%–74% of candidate cases. The results of this study indicate that multiple specific transmission routes are acting to maintain IHNV in juvenile fish, providing concrete evidence that can be used to improve resource management. Furthermore, these results demonstrate that more sophisticated analysis of available spatio-temporal and genetic data is likely to yield greater insight in future studies.

  18. The Response of a Steelhead Trout Population to Wildfire at the Landscape Scale

    NASA Astrophysics Data System (ADS)

    Boughton, D. A.

    2012-12-01

    Wildfire is a prevalent disturbance of watersheds that impacts stream habitats and fish abundance, by direct removal of riparian vegetation and indirect effects on sediment regimes and water quality. Individual studies at the reach scale of the fish Oncorhynchus mykiss (steelhead trout) after wildfire show that habitat- and population-response is highly context dependent, suggesting broad-scale heterogeneity in effects of wildfire, possibly linked to fluvial processes. Here I report the results of a novel study design that examined wildfire response of O. mykiss and its habitat condition at 26 reaches sampled from a stream system heavily burned during the 2008 Indians/Basin Complex Fire in the central California chaparral. Proportional decline in juvenile fish abundances in the year after the wildfire were large but spatially heterogeneous (ranging by 2 orders of magnitude). Influence diagrams suggested that the major impact of the fire on the fish was not direct impacts on riparian vegetation (which were quite minor), but indirect impacts via pulses of fine sediment into channels the following winter. Abundance at some sites increased after the fire; the largest increases were not outside (downstream of) the burned area, but rather were in headwater reaches inside the burned area. In the year after the wildfire, fish abundance rebounded, with magnitude of rebound nearly proportional to the previous year's decline at most sites, suggesting rapid recovery of habitat quality and population recruitment. This study illustrates the importance of spatial structure and fluvial-process diversity for the rapid recovery of a fish after an intense wildfire.

  19. Cold-acclimation leads to differential regulation of the steelhead trout (Oncorhynchus mykiss) coronary microcirculation

    PubMed Central

    Costa, Isabel A. S. F.; Hein, Travis W.

    2015-01-01

    The regulation of vascular resistance in fishes has largely been studied using isolated large conductance vessels, yet changes in tissue perfusion/vascular resistance are primarily mediated by the dilation/constriction of small arterioles. Thus we adapted mammalian isolated microvessel techniques for use in fish and examined how several agents affected the tone/resistance of isolated coronary arterioles (<150 μm ID) from steelhead trout (Oncorhynchus mykiss) acclimated to 1, 5, and 10°C. At 10°C, the vessels showed a concentration-dependent dilation to adenosine (ADE; 61 ± 8%), sodium nitroprusside (SNP; 35 ± 10%), and serotonin (SER; 27 ± 2%) (all values maximum responses). A biphasic response (mild contraction then dilation) was observed in vessels exposed to increasing concentrations of epinephrine (EPI; 34 ± 9% dilation) and norepinephrine (NE; 32 ± 7% dilation), whereas the effect was less pronounced with bradykinin (BK; 12.5 ± 3.5% constriction vs. 6 ± 6% dilation). Finally, a mild constriction was observed after exposure to acetylcholine (ACh; 6.5 ± 1.4%), while endothelin (ET)-1 caused a strong dose-dependent increase in tone (79 ± 5% constriction). Acclimation temperature had varying effects on the responsiveness of vessels. The dilations induced by EPI, ADE, SER, and SNP were reduced/eliminated at 5°C and/or 1°C as compared with 10°C. In contrast, acclimation to 5 and 1°C increased the maximum constriction induced by ACh and the sensitivity of vessels to ET-1 (but not the maximum response) at 1°C was greater. Acclimation temperature had no effect on the response to NE, and responsiveness to BK was variable. PMID:25715834

  20. Testing of male sockeye salmon (Oncorhynchus nerka) and steelhead trout (Salmo gairdneri) for infectious hematopoietic necrosis virus

    USGS Publications Warehouse

    Mulcahy, D.; Pascho, R.J.; Batts, W.N.

    1987-01-01

    Infectious hematopoietic necrosis (IHN) virus has been isolated only rarely from whole milt samples of male sockeye salmon (Oncorhynchus nerka). In 3 yr of testing, virus incidences in males ranged from 0 to 13% when milt was sampled but were 60–100% with spleen or kidney. When IHN virus was isolated from sockeye salmon milt at titers less than 3.00 log10 plaque-forming units (pfu)/mL, the level of virus in the kidney or spleen exceeded 7.00 log10 pfu/g. Higher rates of IHN virus isolation from kidney or spleen than from milt were also generally found in steelhead trout (Salmo gairdneri), although the differences were less pronounced than in sockeye salmon. Furthermore, virus was sometimes isolated from steelhead trout milt when the level of virus in kidney or spleen samples was very low, and was recovered from some milt samples when none was isolated from the corresponding spleen sample. When male salmonids are tested for IHN virus, kidney or spleen samples are superior to whole milt, but milt should be included for critical examinations.

  1. Relative contributions of neutral and non-neutral genetic differentiation to inform conservation of steelhead trout across highly variable landscapes

    PubMed Central

    Matala, Andrew P; Ackerman, Michael W; Campbell, Matthew R; Narum, Shawn R

    2014-01-01

    Mounting evidence of climatic effects on riverine environments and adaptive responses of fishes have elicited growing conservation concerns. Measures to rectify population declines include assessment of local extinction risk, population ecology, viability, and genetic differentiation. While conservation planning has been largely informed by neutral genetic structure, there has been a dearth of critical information regarding the role of non-neutral or functional genetic variation. We evaluated genetic variation among steelhead trout of the Columbia River Basin, which supports diverse populations distributed among dynamic landscapes. We categorized 188 SNP loci as either putatively neutral or candidates for divergent selection (non-neutral) using a multitest association approach. Neutral variation distinguished lineages and defined broad-scale population structure consistent with previous studies, but fine-scale resolution was also detected at levels not previously observed. Within distinct coastal and inland lineages, we identified nine and 22 candidate loci commonly associated with precipitation or temperature variables and putatively under divergent selection. Observed patterns of non-neutral variation suggest overall climate is likely to shape local adaptation (e.g., potential rapid evolution) of steelhead trout in the Columbia River region. Broad geographic patterns of neutral and non-neutral variation demonstrated here can be used to accommodate priorities for regional management and inform long-term conservation of this species. PMID:25067950

  2. Habitat utilization, density, and growth of steelhead trout, coho salmon, and Pacific giant salamander in relation to habitat types in a small coastal redwood stream

    Treesearch

    Michael Roy Lau

    1994-01-01

    Abstract - Small Pacific northwestern coastal streams are nurseries for populations of young of the year coho salmon, steelhead trout, and the Pacific giant salamander larvae. Previous field studies suggest that the habitats of the juveniles of these species were similar to one another. Few habitat utilization studies focus on the juvenile stages of these species...

  3. Willingness-to-pay for steelhead trout fishing: Implications of two-step consumer decisions with short-run endowments

    NASA Astrophysics Data System (ADS)

    McKean, John R.; Johnson, Donn; Taylor, R. Garth

    2010-09-01

    Choice of the appropriate model of economic behavior is important for the measurement of nonmarket demand and benefits. Several travel cost demand model specifications are currently in use. Uncertainty exists over the efficacy of these approaches, and more theoretical and empirical study is warranted. Thus travel cost models with differing assumptions about labor markets and consumer behavior were applied to estimate the demand for steelhead trout sportfishing on an unimpounded reach of the Snake River near Lewiston, Idaho. We introduce a modified two-step decision model that incorporates endogenous time value using a latent index variable approach. The focus is on the importance of distinguishing between short-run and long-run consumer decision variables in a consistent manner. A modified Barnett two-step decision model was found superior to other models tested.

  4. Some physiological consequences of handling stress in the juvenile coho salmon (Oncorhynchus kisutch) and steelhead trout (Salmo gairdneri)

    USGS Publications Warehouse

    Wedemeyer, Gary

    1972-01-01

    The stress of handling juvenile coho salmon (Oncorhynchus kisutch) and steelhead trout (Salmo gairdneri) in soft water and in water with added salts was evaluated using blood and tissue chemistry fluctuations as indices of metabolic and endocrine function. Changes in plasma glucose, chloride, calcium, and cholesterol levels indicated that significant osmoregulatory and metabolic dysfunctions can occur and persist for about 24 hr after handling in soft water. Pituitary activation, as judged by lack of interrenal ascorbate depletion, did not occur. Increasing the ambient NaCl and Ca++ levels to about 100 milliosmols and 75–120 ppm, respectively, partially or completely alleviated the hyperglycemia and hypochloremia indicating that the stress of handling had been reduced.

  5. Spatial partitioning and asymmetric hybridization among sympatric coastal steelhead trout (Oncorhynchus mykiss irideus), coastal cutthroat trout (O. clarki clarki) and interspecific hybrids

    USGS Publications Warehouse

    Ostberg, C.O.; Slatton, S.L.; Rodriguez, R.J.

    2004-01-01

    Hybridization between sympatric species provides unique opportunities to examine the contrast between mechanisms that promote hybridization and maintain species integrity. We surveyed hybridization between sympatric coastal steelhead (Oncorhynchus mykiss irideus) and coastal cutthroat trout (O. clarki clarki) from two streams in Washington State, Olsen Creek (256 individuals sampled) and Jansen Creek (431 individuals sampled), over a 3-year period. We applied 11 O. mykiss-specific nuclear markers, 11 O. c. clarki-specific nuclear markers and a mitochondrial DNA marker to assess spatial partitioning among species and hybrids and determine the directionality of hybridization. F1 and post-F1 hybrids, respectively, composed an average of 1.2% and 33.6% of the population sampled in Jansen Creek, and 5.9% and 30.4% of the population sampled in Olsen Creek. A modest level of habitat partitioning among species and hybrids was detected. Mitochondrial DNA analysis indicated that all F 1 hybrids (15 from Olsen Creek and five from Jansen Creek) arose from matings between steelhead females and cutthroat males implicating a sneak spawning behaviour by cutthroat males. First-generation cutthroat backcrosses contained O. c. clarki mtDNA more often than expected suggesting natural selection against F1 hybrids. More hybrids were backcrossed toward cutthroat than steelhead and our results indicate recurrent hybridization within these creeks. Age analysis demonstrated that hybrids were between 1 and 4 years old. These results suggest that within sympatric salmonid hybrid zones, exogenous processes (environmentally dependent factors) help to maintain the distinction between parental types through reduced fitness of hybrids within parental environments while divergent natural selection promotes parental types through distinct adaptive advantages of parental phenotypes.

  6. Novel molecular markers differentiate Oncorhynchus mykiss (rainbow trout and steelhead) and the O. clarki (cutthroat trout) subspecies

    USGS Publications Warehouse

    Ostberg, C.O.; Rodriguez, R.J.

    2002-01-01

    A suite of 26 PCR-based markers was developed that differentiates rainbow (Oncorhynchus mykiss) and coastal cutthroat trout (O. clarki clarki). The markers also differentiated rainbow from other cutthroat trout subspecies (O. clarki), and several of the markers differentiated between cutthroat trout subspecies. This system has numerous positive attributes, including: nonlethal sampling, high species-specificity and products that are easily identified and scored using agarose gel electrophoresis. The methodology described for developing the markers can be applied to virtually any system in which numerous markers are desired for identifying or differentiating species or subspecies.

  7. Divergence in expression of candidate genes for the smoltification process between juvenile resident rainbow and anadromous steelhead trout.

    PubMed

    Hecht, Benjamin C; Valle, Madeline E; Thrower, Frank P; Nichols, Krista M

    2014-12-01

    Rainbow and steelhead trout (Oncorhynchus mykiss), among other salmonid fishes, exhibit tremendous life history diversity, foremost of which is variation in migratory propensity. While some individuals possess the ability to undertake an anadromous marine migration, others remain resident in freshwater throughout their life cycle. Those that will migrate undergo tremendous physiological, morphological, and behavioral transformations in a process called smoltification which transitions freshwater-adapted parr to marine-adapted smolts. While the behavior, ecology, and physiology of smoltification are well described, our understanding of the proximate genetic mechanisms that trigger the process are not well known. Quantitative genetic analyses have identified several genomic regions associated with smoltification and migration-related traits within this species. Here we investigate the divergence in gene expression of 18 functional and positional candidate genes for the smoltification process in the brain, gill, and liver tissues of migratory smolts, resident parr, and precocious mature male trout at the developmental stage of out-migration. Our analysis reveals several genes differentially expressed between life history classes and validates the candidate nature of several genes in the parr-smolt transformation including Clock1α, FSHβ, GR, GH2, GHR1, GHR2, NDK7, p53, SC6a7, Taldo1, THRα, THRβ, and Vdac2.

  8. Using broad landscape level features to predict redd densities of steelhead trout (Oncorhynchus mykiss) and Chinook Salmon (Oncorhynchus tshawytscha) in the Methow River watershed, Washington

    USGS Publications Warehouse

    Romine, Jason G.; Perry, Russell W.; Connolly, Patrick J.

    2013-01-01

    We used broad-scale landscape feature variables to model redd densities of spring Chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Oncorhynchus mykiss) in the Methow River watershed. Redd densities were estimated from redd counts conducted from 2005 to 2007 and 2009 for steelhead trout and 2005 to 2009 for spring Chinook salmon. These densities were modeled using generalized linear mixed models. Variables examined included primary and secondary geology type, habitat type, flow type, sinuosity, and slope of stream channel. In addition, we included spring effect and hatchery effect variables to account for high densities of redds near known springs and hatchery outflows. Variables were associated with National Hydrography Database reach designations for modeling redd densities within each reach. Reaches were assigned a dominant habitat type, geology, mean slope, and sinuosity. The best fit model for spring Chinook salmon included sinuosity, critical slope, habitat type, flow type, and hatchery effect. Flow type, slope, and habitat type variables accounted for most of the variation in the data. The best fit model for steelhead trout included year, habitat type, flow type, hatchery effect, and spring effect. The spring effect, flow type, and hatchery effect variables explained most of the variation in the data. Our models illustrate how broad-scale landscape features may be used to predict spawning habitat over large areas where fine-scale data may be lacking.

  9. Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Pacific Northwest). Steelhead Trout.

    DTIC Science & Technology

    1986-08-01

    of oxygen concentration on Trans. Am. Fish. Soc. 109(2): the swming performance of juvenile 203-206. Pacific salmon at various temperatures...OREGON Figure 3. Major Washington State rivers that have sumuer-run steelhead. the back, and on the dorsal and caudal of natural habitat and increased...home LIFE HISTORY stream in various stages of maturation and spawn within the next few months Run and Stock Types after entering the river,

  10. Increased natural reproduction and genetic diversity one generation after cessation of a steelhead trout (Oncorhynchus mykiss) conservation hatchery program

    PubMed Central

    Van Doornik, Donald M.

    2018-01-01

    Spatial and temporal fluctuations in productivity and abundance confound assessments of captive propagation programs aimed at recovery of Threatened and Endangered populations. We conducted a 17 year before-after-control-impact experiment to determine the effects of a captive rearing program for anadromous steelhead trout (Oncorhynchus mykiss) on a key indicator of natural spawner abundance (naturally produced nests or ‘redds’). The supplemented population exhibited a significant (2.6-fold) increase in redd abundance in the generation following supplementation. Four non-supplemented (control) populations monitored over the same 17 year period exhibited stable or decreasing trends in redd abundance. Expected heterozygosity in the supplemented population increased significantly. Allelic richness increased, but to a lesser (non-significant) degree. Estimates of the effective number of breeders increased from a harmonic mean of 24.4 in the generation before supplementation to 38.9 after supplementation. Several non-conventional aspects of the captive rearing program may have contributed to the positive response in the natural population. PMID:29351326

  11. The role of beaver in shaping steelhead trout (Oncorhynchus mykiss) habitat complexity and thermal refugia in a central Oregon stream

    NASA Astrophysics Data System (ADS)

    Consolati, F.; Wheaton, J. M.; Neilson, B. T.; Bouwes, N.; Pollock, M. M.

    2012-12-01

    The incised and degraded habitat of Bridge Creek, tributary to the John Day River in central Oregon, is thought to be limiting the local population of ESA-listed steelhead trout (Oncorhynchus mykiss). Restoration efforts for this watershed are aimed to improve their habitat through reconnecting the channel with portions of its former floodplain (now terraces) to increase stream habitat complexity and the extent of riparian vegetation. This is being done via the installation of over a hundred beaver dam support (BDS) structures that are designed to either mimic beaver dams or support existing beaver dams. The overall objective of this study is to determine if the BDS structures have had an effect on stream channel habitat complexity and thermal refugia in selected sections of Bridge Creek. Analysis of stream temperature data in restoration treatment and control areas will show the effects of beaver dams on stream temperature. Analysis of aerial imagery and high resolution topographic data will exhibit how the number and types of geomorphic units have changed after the construction of beaver dams. Combined, the results of this research are aimed to increase our understanding of how beaver dams impact fish habitat and stream temperature.

  12. Increased natural reproduction and genetic diversity one generation after cessation of a steelhead trout (Oncorhynchus mykiss) conservation hatchery program.

    PubMed

    Berejikian, Barry A; Van Doornik, Donald M

    2018-01-01

    Spatial and temporal fluctuations in productivity and abundance confound assessments of captive propagation programs aimed at recovery of Threatened and Endangered populations. We conducted a 17 year before-after-control-impact experiment to determine the effects of a captive rearing program for anadromous steelhead trout (Oncorhynchus mykiss) on a key indicator of natural spawner abundance (naturally produced nests or 'redds'). The supplemented population exhibited a significant (2.6-fold) increase in redd abundance in the generation following supplementation. Four non-supplemented (control) populations monitored over the same 17 year period exhibited stable or decreasing trends in redd abundance. Expected heterozygosity in the supplemented population increased significantly. Allelic richness increased, but to a lesser (non-significant) degree. Estimates of the effective number of breeders increased from a harmonic mean of 24.4 in the generation before supplementation to 38.9 after supplementation. Several non-conventional aspects of the captive rearing program may have contributed to the positive response in the natural population.

  13. Individual condition and stream temperature influences early maturation of rainbow and steelhead trout, Oncorhynchus mykiss

    Treesearch

    John R. McMillan; Jason B. Dunham; Gordon H. Reeves; Justin S. Mills; Chris E. Jordan

    2012-01-01

    Alternative male phenotypes in salmonine fishes arise from individuals that mature as larger and older anadromous marine-migrants or as smaller and younger freshwater residents. To better understand the processes influencing the expression of these phenotypes we examined the influences of growth in length (fork length) and whole body lipid content in rainbow trout (...

  14. Performance of juvenile steelhead trout (Oncorhynchus mykiss) produced from untreated and cryopreserved milt

    USGS Publications Warehouse

    Hayes, Michael C.; Rubin, Stephen P.; Hensleigh, Jay E.; Reisenbichler, Reginald R.; Wetzel, Lisa A.

    2005-01-01

    Despite the expanding use of milt cryopreservation in aquaculture, the performance of fish produced from this technique has not been fully explored beyond initial rearing stages. We compared the performance of juvenile steelhead Oncorhynchus mykiss produced from untreated (UM) and cryopreserved milt (CM) and reared for 4–9 months. For the 1996 brood, CM alevins were heavier (∼ 1.7%, P < 0.01) than UM alevins and length was influenced by a significant milt-by-family interaction (P < 0.03) suggesting a greater treatment effect for some families. No significant differences were found in length or weight (P > 0.05) for 1997 brood alevins and percent yolk was similar for both broods (P > 0.34). In growth and survival experiment I (GSE-I, 1996), UM and CM juveniles reared in separate tanks and fed to satiation (130 days) showed no significant differences in survival, length or weight (P > 0.05) between milt groups. In contrast, for UM and CM siblings reared in the same tank for 210 days on a low food ration (GSE-II), survival was similar (P > 0.05), but length (UM 4% > CM, P < 0.05) and possibly weight (UM 15% > CM, P = 0.08), were influenced by cryopreservation. Fish from the 1997 brood (GSE-III) were reared for 313 days in a repeat of GSE-II and no differences were found in survival (P = 0.47), length (P = 0.75) or weight (P = 0.76) suggesting considerable heterogeneity between broods. Performance of the 1996 brood was also tested for response to stress and a disease challenge. Cortisol responses of juveniles exposed to acute stress were not significantly different (P = 0.19), but mean cortisol was consistently and significantly greater (P < 0.01) for CM than UM fish exposed to a 48-h stress (increased density). After exposure to three dosages of the bacteria, Listonella anguillarum, we found similar mortality proportions (P = 0.72) for UM and CM fish. Variable juvenile performance for the parameters tested indicated significant

  15. Evaluation of Fishway Designs for Downstream Passage of Spring Chinook Salmon and Steelhead Trout Smolts, 1987 Final Report.

    SciTech Connect

    Congleton, J.L.; Wagner, E.J.; Ringe, R.R.

    1988-03-01

    The stress response of chinook salmon and steelhead trout smolts to passage through three different flumes was tested by assaying plasma cortisol concentrations before and after flume passage. In addition, descaling of fish was recorded before and after flume passage, and the ability of the flumes to pass adult chinook salmon and debris was determined. The three flumes were a corrugated metal flume (CMF), a 4- foot wide baffled flume (BF4), and a 2-foot wide baffled flume (BF2). Each flume was tested under conditions: 1) at night, 2) during the day with a perforated metal cover, which reduced the amountmore » of light entering the flume by about half (partially darkened), and 3) during the day with the perforated cover and additional double layer of black plastic (completely darkened). Plasma cortisol concentrations were not significantly elevated in chinook salmon smolts after passage through any of the flumes (P>0.2, ANOVA). In daytime tests of partially and completely darkened flumes cortisol concentrations were consistently decreased following flume passage. We attribute this to pre-test stress (holding of fish in small tanks) and to the absence of a strong stress response to flume passage. Flume design did not have a significant effect on cortisol concentrations (P=0.9).Total darkening of the flumes during daytime was beneficial: cortisol concentrations were lower (P=0.03) in chinook salmon smolts passing through completely darkened flumes than in smolts passing through partially darkened flumes. 16 refs., 15 figs.« less

  16. Resistance of different stocks and transferrin genotypes of coho salmon, Oncorhynchus kisutch, and steelhead trout, Salmo gairdneri, to bacterial kidney disease and vibriosis

    USGS Publications Warehouse

    Winter , Gary W.; Schreck, Carl B.; McIntyre, John D.

    1979-01-01

    Juvenile coho salmon and steelhead trout ofdifferentstocks and three transferrin genotypes(AA, AC, and CCl, all reared in identical or similar environments, were experimentally infected with Corynebacterium sp., the causative agent ofbacterial kidney disease, or with Vibrio anguillarum, the causative agent of vibriosis. Mortality due to the pathogens was compared among stocks within a species and among transferrin genotypes within a stock to determine whetherthere was a geneticbasis for resistance to disease. Differences in resistance to bacterial kidney disease among coho salmon stocks had a genetic basis. Stock susceptibility to vibriosis was strongly influenced by environmental factors. Coho salmon orsteelhead trout of one stock may be resistant to one disease but susceptible to another. The importance of transferrin genotype of coho salmon in resistance to bacterial kidney disease was stock specific; in stocks that showed differential resistance of genotypes, the AA was the most susceptible. No differencesin resistance to vibriosis were observed among transferrin genotypes.

  17. Imprinting Hatchery Reared Salmon and Steelhead Trout for Homing, Volume I of III; Narrative, 1978-1983 Final Report.

    SciTech Connect

    Slatick, Emil; Gilbreath, Lyle G.; Harmon, Jerrel R.

    1988-02-01

    The National Marine Fisheries Service began conducting homing research on Pacific salmon and steelhead. Over 4 million juvenile salmon and steelhead were marked and released, and 23 individual experiments were conducted. The research had the following objectives: (1) develop the techniques for imprinting homing cues while increasing survival of hatchery reared salmonids and (2) provide fishery managers with the information necessary to increase the returns of salmon and steelhead to the Columbia River system and to effectively distribute these fish to the various user groups. Our imprint methods were grouped into three general categories: (1) natural migration imprint from amore » hatchery of origin or an alternate homing site (by allowing fish to volitionally travel downstream through the river on their seaward journey), (2) single exposure imprinting (cueing fish to a single unique water supply with or without mechanical stimuli prior to transport and release), and (3) sequential exposure imprinting (cueing fish to two or more water sources in a step-by-step process to establish a series of signposts for the route ''home''). With variations, all three techniques were used with all salmonid groups tested: coho salmon, spring and fall chinook salmon, and steelhead. For the single and sequential imprint, fish were transported around a portion of their normal migration route before releasing them into the Columbia River.« less

  18. The impact of small irrigation diversion dams on the recent migration rates of steelhead and redband trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Weigel, Dana E.; Connolly, Patrick J.; Powell, Madison S.

    2013-01-01

    Barriers to migration are numerous in stream environments and can occur from anthropogenic activities (such as dams and culverts) or natural processes (such as log jams or dams constructed by beaver (Castor canadensis)). Identification of barriers can be difficult when obstructions are temporary or incomplete providing passage periodically. We examine the effect of several small irrigation diversion dams on the recent migration rates of steelhead (Oncorhynchus mykiss) in three tributaries to the Methow River, Washington. The three basins had different recent migration patterns: Beaver Creek did not have any recent migration between sites, Libby Creek had two-way migration between sites and Gold Creek had downstream migration between sites. Sites with migration were significantly different from sites without migration in distance, number of obstructions, obstruction height to depth ratio and maximum stream gradient. When comparing the sites without migration in Beaver Creek to the sites with migration in Libby and Gold creeks, the number of obstructions was the only significant variable. Multinomial logistic regression identified obstruction height to depth ratio and maximum stream gradient as the best fitting model to predict the level of migration among sites. Small irrigation diversion dams were limiting population interactions in Beaver Creek and collectively blocking steelhead migration into the stream. Variables related to stream resistance (gradient, obstruction number and obstruction height to depth ratio) were better predictors of recent migration rates than distance, and can provide important insight into migration and population demographic processes in lotic species.

  19. Study 8: Prevalence and load of Nanophyetus salmincola infection in outmigrating steelhead trout from five Puget Sound rivers

    USGS Publications Warehouse

    Chen, M.F.; Stewart, B.A.; Senkvik, Kevin; Hershberger, Paul

    2015-01-01

    Nanophyetus salmincola is a parasitic trematode, or flatworm, that infects salmonid fishes in the Pacific Northwest, including Washington, Oregon, and portions of California. The adult worm lives in the intestine of fish-eating birds and mammals. Eggs shed into the water hatch into miracidia which penetrate the first intermediate host, one of two species of snail Juga plicifera or J. silicula. Asexual reproduction occurs within the snail. Free-swimming cercaria are released from the snail and penetrate the secondary intermediate host, often a salmonid fish, in fresh and brackish water. The cercaria encyst as metacercaria in various organs of the fish, including gills, muscle and heart, but favor the posterior kidney. Penetration and migration by the cercaria through the fish causes damage to nearly every organ system. Once encysted, metacercaria survive the ocean phase of salmonid life cycle. N. salmincola is a likely contributor to mortality of juvenile coho salmon (Oncorhynchus kisutch) during the early ocean rearing phase, and it is the most prevalent pathogen of outmigrating steelhead in the estuaries of the Pacific Northwest.A field survey was implemented from March-June 2014 to compare the prevalence and parasite load of N. salmincola infections in outmigrating steelhead from five Puget Sound watersheds and to assess changes in infection levels that occurred during the smolt out-migration through each watershed. N. salmincola infection prevalence and parasite loads were determined by counting metacercaria in posterior kidney samples. Tissue samples were collected and examined by standard histological methods.

  20. The effects of riverine physical complexity on anadromy and genetic diversity in steelhead or rainbow trout Oncorhynchus mykiss around the Pacific Rim.

    PubMed

    McPhee, M V; Whited, D C; Kuzishchin, K V; Stanford, J A

    2014-07-01

    This study explored the relationship between riverine physical complexity, as determined from remotely sensed metrics, and anadromy and genetic diversity in steelhead or rainbow trout Oncorhynchus mykiss. The proportion of anadromy (estimated fraction of individuals within a drainage that are anadromous) was correlated with riverine complexity, but this correlation appeared to be driven largely by a confounding negative relationship between drainage area and the proportion of anadromy. Genetic diversity decreased with latitude, was lower in rivers with only non-anadromous individuals and also decreased with an increasing ratio of floodplain area to total drainage area. Anadromy may be less frequent in larger drainages due to the higher cost of migration associated with reaches farther from the ocean, and the negative relationship between genetic diversity and floodplain area may be due to lower effective population size resulting from greater population fluctuations associated with higher rates of habitat turnover. Ultimately, the relationships between riverine physical complexity and migratory life history or genetic diversity probably depend on the spatial scale of analysis. © 2014 The Fisheries Society of the British Isles.

  1. Fatty-acid profiles of white muscle and liver in stream-maturing steelhead trout Oncorhynchus mykiss from early migration to kelt emigration

    USGS Publications Warehouse

    Penney, Zachary L.; Moffitt, Christine M.

    2015-01-01

    The profiles of specific fatty acids (FA) in white muscle and liver of fasting steelhead troutOncorhynchus mykiss were evaluated at three periods during their prespawning migration and at kelt emigration in the Snake–Columbia River of Washington, Oregon and Idaho, to improve the understanding of energy change. Twenty-seven FAs were identified; depletion of 10 of these was positively correlated in liver and white muscle of prespawning O. mykiss. To observe relative changes in FA content more accurately over sampling intervals, the lipid fraction of tissues was used to normalize the quantity of individual FA to an equivalent tissue wet mass. Saturated and monounsaturated FAs were depleted between upstream migration in September and kelt emigration in June, whereas polyunsaturated FAs were more conserved. Liver was depleted of FAs more rapidly than muscle. Three FAs were detected across all sampling intervals: 16:0, 18:1 and 22:6n3, which are probably structurally important to membranes. When structurally important FAs of O. mykiss are depleted to provide energy, physiological performance and survival may be affected.

  2. Effective population size of steelhead trout: influence of variance in reproductive success, hatchery programs, and genetic compensation between life-history forms.

    PubMed

    Araki, Hitoshi; Waples, Robin S; Ardren, William R; Cooper, Becky; Blouin, Michael S

    2007-03-01

    The effective population size is influenced by many biological factors in natural populations. To evaluate their relative importance, we estimated the effective number of breeders per year (Nb) and effective population size per generation (Ne) in anadromous steelhead trout (Oncorhynchus mykiss) in the Hood River, Oregon (USA). Using demographic data and genetic parentage analysis on an almost complete sample of all adults that returned to the river over 15 years (>15,000 individuals), we estimated Nb for 13 run years and Ne for three entire generations. The results are as follows: (i) the ratio of Ne to the estimated census population size (N) was 0.17-0.40, with large variance in reproductive success among individuals being the primary cause of the reduction in Ne/N; (ii) fish from a traditional hatchery program (Htrad: nonlocal, multiple generations in a hatchery) had negative effects on Nb, not only by reducing mean reproductive success but also by increasing variance in reproductive success among breeding parents, whereas no sign of such effects was found in fish from supplementation hatchery programs (Hsupp: local, single generation in a hatchery); and (iii) Nb was relatively stable among run years, despite the widely fluctuating annual run sizes of anadromous adults. We found high levels of reproductive contribution of nonanadromous parents to anadromous offspring when anadromous run size is small, suggesting a genetic compensation between life-history forms (anadromous and nonanadromous). This is the first study showing that reproductive interaction between different life-history forms can buffer the genetic impact of fluctuating census size on Ne.

  3. Little impact of hatchery supplementation that uses native broodstock on the genetic structure and diversity of steelhead trout revealed by a large-scale spatio-temporal microsatellite survey

    PubMed Central

    Gow, Jennifer L; Tamkee, Patrick; Heggenes, Jan; Wilson, Greg A; Taylor, Eric B

    2011-01-01

    Artificial breeding programs initiated to enhance the size of animal populations are often motivated by the desire to increase harvest opportunities. The introduction of non-native genotypes, however, can have negative evolutionary impacts. These may be direct, such as introgressive hybridization, or indirect via competition. Less is known about the effects of stocking with native genotypes. We assayed variation at nine microsatellite loci in 902 steelhead trout (Oncorhynchus mykiss) from five rivers in British Columbia, Canada. These samples were collected over 58 years, a time period that spanned the initiation of native steelhead trout broodstock hatchery supplementation in these rivers. We detected no changes in estimates of effective population size, genetic variation or temporal genetic structure within any population, nor of altered genetic structure among them. Genetic interactions with nonmigratory O. mykiss, the use of substantial numbers of primarily native broodstock with an approximate 1:1 male-to-female ratio, and/or poor survival and reproductive success of hatchery fish may have minimized potential genetic changes. Although no genetic changes were detected, ecological effects of hatchery programs still may influence wild population productivity and abundance. Their effects await the design and implementation of a more comprehensive evaluation program. PMID:25568021

  4. Life history diversity in Klamath River steelhead

    USGS Publications Warehouse

    Hodge, Brian W.; Wilzbach, Peggy; Duffy, Walter G.; Quinones, Rebecca M.; Hobbs, James A.

    2016-01-01

    Oncorhynchus mykiss exhibits a vast array of life histories, which increases its likelihood of persistence by spreading risk of extirpation among different pathways. The Klamath River basin (California–Oregon) provides a particularly interesting backdrop for the study of life history diversity in O. mykiss, in part because the river is slated for a historic and potentially influential dam removal and habitat recolonization project. We used scale and otolith strontium isotope (87Sr/86Sr) analyses to characterize life history diversity in wildO. mykiss from the lower Klamath River basin. We also determined maternal origin (anadromous or nonanadromous) and migratory history (anadromous or nonanadromous) of O. mykiss and compared length and fecundity at age between anadromous (steelhead) and nonanadromous (Rainbow Trout) phenotypes of O. mykiss. We identified a total of 38 life history categories at maturity, which differed in duration of freshwater and ocean rearing, age at maturation, and incidence of repeat spawning. Approximately 10% of adult fish sampled were nonanadromous. Rainbow Trout generally grew faster in freshwater than juvenile steelhead; however, ocean growth afforded adult steelhead greater length and fecundity than adult Rainbow Trout. Although 75% of individuals followed the migratory path of their mother, steelhead produced nonanadromous progeny and Rainbow Trout produced anadromous progeny. Overall, we observed a highly diverse array of life histories among Klamath River O. mykiss. While this diversity should increase population resilience, recent declines in the abundance of Klamath River steelhead suggest that life history diversity alone is not sufficient to stabilize a population. Our finding that steelhead and Rainbow Trout give rise to progeny of the alternate form (1) suggests that dam removal might lead to a facultatively anadromous O. mykiss population in the upper basin and (2) raises the question of whether both forms of

  5. Early ocean survival and marine movements of hatchery and wild steelhead trout ( Oncorhynchus mykiss) determined by an acoustic array: Queen Charlotte Strait, British Columbia

    NASA Astrophysics Data System (ADS)

    Welch, David W.; Ward, Bruce R.; Batten, Sonia D.

    2004-03-01

    Early ocean movements, residency, and survival of steelhead (Oncorhynchus mykiss) were examined in Queen Charlotte Strait, a large (20×100 km2) marine area separating Vancouver Island from the mainland. The results provide the first detailed data on the ocean biology of hatchery and wild steelhead smolts. Initial ocean movements were not strongly directed, with most smolts swimming in the range of 0.2-0.5 body length (BL) s-1. The majority (78%) vacated Queen Charlotte Strait within 1 week of release in freshwater. Relative marine survival of hatchery smolts surgically implanted 1 month prior to release was identical to that of wild smolts implanted on the day of release; survival of hatchery smolts transported to the study site, implanted, and released all on the same day was significantly lower. The results suggest that the early marine survival of hatchery and wild smolts may be fundamentally similar, but that the cumulative stress of transportation and surgery may reduce post-surgery survival. Hatchery smolts moved at higher average swimming speeds than wild smolts, but the difference was not statistically significant. Early marine survival within the study region appears to be relatively high (⩾55%), contradicting assumptions that the early marine phase is the critical period for determining salmon recruitment.

  6. Seasonal variation in habitat use of juvenile Steelhead in a tributary of Lake Ontario

    USGS Publications Warehouse

    Studdert, Emily W.; Johnson, James H.

    2015-01-01

    We examined seasonal-habitat use by subyearling and yearling Oncorhynchus mykiss (Rainbow Trout or Steelhead) in Trout Brook, a tributary of the Salmon River, NY. We determined daytime fish-habitat use and available habitat during August and October of the same year and observed differences in habitat selection among year classes. Water depth and cover played the greatest role in Steelhead habitat use. During summer and autumn, we found yearling Steelhead in areas with deeper water and more cover than where we observed subyearling Steelhead. Both year classes sought out areas with abundant cover during both seasons; this habitat was limited within the stream reach. Subyearling Steelhead were associated with more cover during autumn, even though available cover within the stream reach was greater during summer. Principal component analysis showed that variation in seasonal-habitat use was most pronounced for subyearling Steelhead and that yearling Steelhead were more selective in their habitat use than subyearling Steelhead. The results of this study contribute to a greater understanding of how this popular sportfish is adapting to a new environment and the factors that may limit juvenile Steelhead survival. Our findings provide valuable new insights into the seasonal-habitat requirements of subyearling and yearling Steelhead that can be used by fisheries managers to enhance and protect the species throughout the Great Lakes region.

  7. Monitoring and Evaluation of Smolt Migration in the Columbia River Basin : Volume VI : Evaluation of the 2000 Predictions of the Run-Timing of Wild Migrant Chinook Salmon and Steelhead Trout, and Hatchery Sockeye Salmon in the Snake River Basin, and Combined Wild Hatchery Salminids Migrating to Rock Island and McNary Dams using Program RealTime.

    SciTech Connect

    Burgess, Caitlin

    1998-07-01

    Program RealTime provided tracking and forecasting of the 2000 in season outmigration via the internet for stocks of wild PIT-tagged spring/summer chinook salmon. These stocks were ESUs from nineteen release sites above Lower Granite dam, including Bear Valley Creek, Big Creek, Camas Creek (new), Cape Horn Creek, Catherine Creek, Elk Creek, Herd Creek, Imnaha River, Johnson Creek (new), Lake Creek, Loon Creek, Lostine River, Marsh Creek, Minam River, East Fork Salmon River (new), South Fork Salmon River, Secesh River, Sulfur Creek and Valley Creek. Forecasts were also provided for two stocks of hatchery-reared PIT-tagged summer-run sockeye salmon, from Redfish Lakemore » and Alturas Lake (new); for a subpopulation of the PIT-tagged wild Snake River fall subyearling chinook salmon; for all wild Snake River PIT-tagged spring/summer yearling chinook salmon (new) and steelhead trout (new)detected at Lower Granite Dam during the 2000 outmigration. The 2000 RealTime project began making forecasts for combined wild- and hatchery-reared runs-at-large of subyearling and yearling chinook, coho, and sockeye salmon, and steelhead trout migrating to Rock Island and McNary Dams on the mid-Columbia River and the mainstem Columbia River. Due to the new (in 1999-2000) Snake River basin hatchery protocol of releasing unmarked hatchery-reared fish, the RealTime forecasting project no longer makes run-timing forecasts for wild Snake River runs-at-large using FPC passage indices, as it has done for the previous three years (1997-1999). The season-wide measure of Program RealTime performance, the mean absolute difference (MAD) between in-season predictions and true (observed) passage percentiles, improved relative to previous years for nearly all stocks. The average season-wide MAD of all (nineteen) spring/summer yearling chinook salmon ESUs dropped from 5.7% in 1999 to 4.5% in 2000. The 2000 MAD for the hatchery-reared Redfish Lake sockeye salmon ESU was the lowest recorded, at 6

  8. Colonization of steelhead in a natal stream after barrier removal

    USGS Publications Warehouse

    Weigel, Dana E.; Connolly, Patrick J.; Martens, Kyle D.; Powell, Madison S.

    2013-01-01

    Colonization of vacant habitats is an important process for supporting the long-term persistence of populations and species. We used a before–after experimental design to follow the process of colonization by steelhead Oncorhynchus mykiss (anadromous Rainbow Trout) at six monitoring sites in a natal stream, Beaver Creek, after the modification or removal of numerous stream passage barriers. Juvenile O. mykiss were collected at monitoring sites by using a backpack electrofisher. Passive integrated transponder tags and instream tag reading stations were used in combination with 16 microsatellite markers to determine the source, extent, and success of migrant O. mykiss after implementation of the barrier removal projects. Steelhead migrated into the study area during the first spawning season after passage was established. Hatchery steelhead, although comprising more than 80% of the adult returns to the Methow River basin, constituted a small proportion (23%) of the adult O. mykiss colonizing the study area. Adult steelhead and fluvial Rainbow Trout entered the stream during the first spawning season after barrier removal and were passing the uppermost tag reader (12 km upstream from the mouth) 3–4 years later. Parr that were tagged in Beaver Creek returned as adults, indicating establishment of the anadromous life history in the study area. Population genetic measures at the lower two monitoring sites (lower 4 km of Beaver Creek) significantly changed within one generation (4–5 years). Colonization and expansion of steelhead occurred more slowly than expected due to the low number of adults migrating into the study area.

  9. Ecological interactions between hatchery summer steelhead and wild Oncorhynchus mykiss in the Willamette River basin, 2014

    SciTech Connect

    Harnish, Ryan A.; Green, Ethan D.; Vernon, Christopher R.

    2014-12-01

    The purpose of this study was to determine the extent to which juvenile hatchery summer steelhead and wild winter steelhead overlap in space and time, to evaluate the extent of residualism among hatchery summer steelhead in the South Santiam River, and to evaluate the potential for negative ecological interactions among hatchery summer steelhead and wild winter steelhead. Because it is not possible to visually discern juvenile winter steelhead from resident rainbow trout, we treated all adipose-intact juvenile O. mykiss as one group that represented juvenile wild winter steelhead. The 2014 study objectives were to 1) estimate the proportion of hatcherymore » summer steelhead that residualized in the South Santiam River in 2014, 2) determine the extent to which hatchery and naturally produced O. mykiss overlapped in space and time in the South Santiam River, and 3) characterize the behavioral interactions between hatchery-origin juvenile summer steelhead and naturally produced O. mykiss. We used a combination of radio telemetry and direct observations (i.e., snorkeling) to determine the potential for negative interactions between hatchery summer and wild winter steelhead juveniles in the South Santiam River. Data collected from these two independent methods indicated that a significant portion of the hatchery summer steelhead released as smolts did not rapidly emigrate from the South Santiam River in 2014. Of the 164 radio-tagged steelhead that volitionally left the hatchery, only 66 (40.2%) were detected outside of the South Santiam River. Forty-four (26.8% of 164) of the radio-tagged hatchery summer steelhead successfully emigrated to Willamette Falls. Thus, the last known location of the majority of the tagged fish (98 of 164 = 59.8%) was in the South Santiam River. Thirty-three of the tagged hatchery steelhead were detected in the South Santiam River during mobile-tracking surveys. Of those, 21 were found to be alive in the South Santiam River over three

  10. Linking habitat quality with trophic performance of steelhead along forest gradients in the South Fork Trinity River watershed, California

    Treesearch

    Sarah G. McCarthy; Jeffrey J. Duda; John M. Emlen; Garth R. Hodgson; David A. Beauchamp

    2009-01-01

    We examined invertebrate prey, fish diet, and energy assimilation in relation to habitat variation for steelhead Oncorhynchus mykiss (anadromous rainbow trout) and rainbow trout in nine low-order tributaries of the South Fork Trinity River, northern California. These streams spanned a range of environmental conditions, which allowed us to use...

  11. California salmon and steelhead: Beyond the crossroads

    USGS Publications Warehouse

    Mills, Terry J.; McEwan, Dennis R.; Jennings, Mark R.; Stouder, Deanna J.; Bisson, Peter A.; Naiman, Robert J.

    1997-01-01

    trout (O. clarki), which are restricted to lowland drainages from the Eel River northward, are greatly depleted. Coho salmon (O. kisutch),which once probably numbered close to 1,000,000 fish per year in coastal California streams, have dwindled to —5,000 natural spawners per year. Chum salmon (O. keta), never a significant part of the state’s native fish fauna, are currently restricted to <10 spawners in three different streams in the Sacramento River basin and occasionally in the South Fork of the Trinity River. The historically small runs of pink salmon (O. gorbuscha) in the Sacramento and Russian rivers are probably now extirpated. Anadromous sockeye salmon (O. nerka) are only recorded as strays.In response to serious declines in salmon and steelhead stocks, numerous legislative and congressional actions have been undertaken and California has embarked on an ambitious planto restore riparian habitats, improve fish passage, and increase natural production. Additionally, many currently unlisted California salmon and steelhead stocks are potential candidates for protection under the Endangered Species Act. These include coho, chum, spring-run chinook, and San Joaquin fall-run chinook salmon, as well as summer steelhead and the southern race of winter steelhead.

  12. Effects of steelhead density on growth of Coho salmon in a small coastal California stream

    Treesearch

    Bret C. Harvey; Rodney J. Nakamoto

    1996-01-01

    Abstract - Weight change in age-0 coho salmon, Oncorhynchus kisutch at about natural density was negatively related to the density of juvenile steelhead (anadromous rainbow trout O. mykiss) in a 6-week experiment conducted in July-August 1993 in the north and south forks of Caspar Creek, California. The experiment used 12 enclosed stream sections, each containing a...

  13. Movement and feeding ecology of recently emerged steelhead in Lake Ontario tributaries

    USGS Publications Warehouse

    Johnson, James H.; McKenna, James E.; Douglass, Kevin A.

    2012-01-01

    Steelhead (Oncorhynchus mykiss) ascend several Lake Ontario tributaries to spawn and juveniles are often the most abundant salmonid where spawning is successful. Movement and diet of recently emerged subyearling steelhead were examined in three New York tributaries of Lake Ontario. Downstream movement occurred mainly at night and consisted of significantly smaller fry that were feeding at lower levels than resident fry. Fry fed at the highest rate during the day and chironomids and baetids were the main components of their diet. The diet composition of steelhead fry was closely associated with the composition of the benthos in Trout Brook but more similar to the composition of the drift in the other streams. Daily ration was similar among streams, ranging from 10.2 to 14.3%. These findings are consistent with previous findings on the ecology of steelhead fry, as well as fry of other salmonid species

  14. Environmental enrichment in steelhead (Oncorhynchus mykiss) hatcheries: Field evaluation of aggression, foraging, and territoriality in natural and hatchery fry

    USGS Publications Warehouse

    Tatara, C.P.; Riley, S.C.; Scheurer, J.A.

    2008-01-01

    Reforms for salmonid hatcheries include production of hatchery fish with behavioral characteristics similar to wild conspecifics. Enrichment of the hatchery environment has been proposed to achieve this goal. Field experiments of steelhead (i.e., sea-run rainbow trout, Oncorhynchus mykiss) fry from a common stock reared under natural (i.e., stream), enriched hatchery, and conventional hatchery conditions indicated no significant differences in the rates of foraging or aggression between rearing treatments. However, the rates of foraging and aggression of natural fry were significantly affected by the type of hatchery fry stocked with them. Natural steelhead fry fed at lower rates and exhibited higher rates of aggression when stocked with steelhead fry raised in enriched hatchery environments. Territory sizes of steelhead fry ranged from 0.015 to 0.801 m2; were significantly, positively related to body length; and were not significantly different between rearing treatments. We conclude that hatchery steelhead fry released into streams establish territories that are proportional to their body length and similar in size to territories of natural steelhead fry. Our results indicate that both conventional and enriched hatchery environments produce natural social behaviors in steelhead released as fry and that fry from enriched hatchery environments may alter the foraging and aggressive behavior of natural, resident steelhead fry. ?? 2008 NRC.

  15. The needs of salmon and steelhead in balancing their conservation and use

    USGS Publications Warehouse

    Burger, Carl V.; Knudsen, E. Eric; Steward, Cleveland R.; MacDonald, Donald D.; Williams, Jack E.; Reiser, Dudley W.

    1999-01-01

    Over the past 100 years, Pacific salmon Oncorhynchus spp. and steelhead trout O. mykiss populations in the Pacific Northwest have experienced dramatic declines as a result of human population growth and associated development of the region's natural resources. Any strategy to reverse those declines will depend on achieving consensus among a diverse group of stakeholders willing to (1) restore damaged habitats and watersheds; (2) consider the biological needs of salmonid fishes; and (3) understand, conserve, and manage existing levels of biodiversity within an ecosystem context. The objective of this chapter is to review and summarize the needs of Pacific salmon and steelhead trout from perspectives that promote their sustainability and perpetuity, and, within that context, provide a framework, for the development of a sustainable fisheries strategy. Although volumes of information are available on the life histories and habitat requirements of Pacific salmonids, new concepts have begun to address the importance of habitat complexity, genetic diversity among locally adapted populations, and the need for appropriate units of conservation. Habitat variability and complexity are the templates that produce diverse, locally adapted populations of Pacific salmon and steelhead trout. Molded by conditions in the environments they colonized, salmon and steelhead have unique adaptations they may have taken hundred i?? perhaps thousands i?? of years to evolve. Any strategy to reverse the declines of salmon and steelhead must focus on conserving both current levels of genetic diversity as well as restoration and maintenance of habitats compatible with the specific needs of individual populations. An argument can be made that we know enough already about the needs of our salmon and steelhead to allow us to make appropriate decisions. There is strong need to integrate what we know about local salmonid adaptations and habitat needs with conservation and management strategies that

  16. Microsatellite analyses of San Franciscuito Creek rainbow trout

    USGS Publications Warehouse

    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.

  17. Juvenile salmon and steelhead occupancy of stream pools treated and not treated with restoration structures, Entiat River, Washington

    Treesearch

    Karl M. Polivka; E. Ashley Steel; Jenni L. Novak; Bror Jonsson

    2015-01-01

    We observed habitat occupancy by juvenile Chinook salmon (Oncorhynchus tschawytscha) and steelhead trout (Oncorhynchus mykiss) at in-stream habitat restoration structures constructed in the Entiat River, Washington, USA. In 2009–2013, fish abundance measurements during rearing (July–October) showed high temporal variability in...

  18. Steelhead Spawning Surveys Near Locke Island, Hanford Reach of the Columbia River

    SciTech Connect

    Geist,; Mueller, RP

    1999-10-19

    In 1997, the National Marine Fisheries Service (NMFS) listed upper Columbia River steelhead trout (Oncorhynchus znykiss) as endangered. This action affected management of land-use activities along and within the Hanford Reach of the Columbia River, which flows through the U.S. Department of Energy (DOE) Hanford Site. Steelhead covered in this listing include all naturally spawned populations of steel-head and their progeny in streams in the Columbia River Basin upstream from the Yakima River to the United States/Canada border. The NMFS has identified a general listing of activities that could potentially result in harm to steelhead (62 FR 43937, August 18,more » 1997). One of these concerns includes land-use changes resulting in mass wasting or surface erosion. Landslide activity along the White Bluffs on the east ,side of Locke Island has redirected river flow into the island where substantial erosion has occurred. This erosion has exposed important anthropological and archaeological resources that were previously buried on the island. The DOE is working with affected tribes and other agencies to develop a plan for addressing the erosion of Locke Island. As part of this effort, the U.S. Army Corps of Engineers has prepared an assessment of potential alternatives to stabilize the erosion, including a no-action alternative. Steelhead historically spawned in the vicinity of Locke Island, but recent information on the occurrence of steelhead spawning or availability of spawning habitat was lacking. Therefore, the purpose of this study was to determine if steelhead spawned in the vicinity of Locke Island erosion and to evaluate the composition of substrate in the affected area. Surveys to document the occurrence of steelheads redds were conducted in Spring 1999. The surveys were conducted from the air as well as with the use of an underwater video camera. Neither aerial nor underwater surveys documented steelhead spawning within the survey area. Habitat surveys were

  19. Microsatellite diversity and conservation of a relic trout population: McCloud River redband trout.

    PubMed

    Nielsen, J L; Crow, K D; Fountain, M C

    1999-12-01

    Rainbow trout native to the McCloud River, California, USA (Oncorhynchus mykiss stonei) are thought to represent a relic, nonanadromous trout adapted to harsh, fragmented environments. These fish, commonly named McCloud River 'redband' trout, survive in their most primitive form in a small, spring-fed stream, Sheepheaven Creek, in the upper McCloud River drainage. Turn-of-the-century fisheries records document both coastal anadromous steelhead and freshwater resident trout within the McCloud River drainage. The phylogenetic position of the McCloud River redband trout within O. mykiss has been debated for over 50 years. Based on phenotypic evidence, these fish were first reported as 'southern Sierra golden trout' by Wales in 1939. Behnke (1970) considered them a relic subspecies of nonanadromous, fine-scaled trout. Allozyme and mitochondrial DNA evidence suggested a coastal lineage. In this study, we examined within- and among-basin genetic associations for Sheepheaven Creek redband trout using 11 microsatellite loci. Within-basin analyses supported unique genetic characteristics in Sheepheaven Creek's trout in comparisons with other McCloud River rainbow trout. Microsatellite data supported significant independence between Sheepheaven Creek fish and hatchery rainbow trout. Inter-basin genetic distance analyses positioned Sheepheaven Creek fish with samples collected from Lassen Creek, a geographically proximate stream containing inland redband trout. California's redband trout shared a close genetic association with Little Kern River golden trout (O.m. whitei) and isolated rainbow trout from Rio Santo Domingo, Baja, Mexico (O.m. nelsoni), suggesting a vicariant distribution of microsatellite diversity throughout the southern range of this species.

  20. Microsatellite diversity and conservation of a relic trout population: McCloud River redband trout

    USGS Publications Warehouse

    Nielsen, J.L.; Crow, K.D.; Fountain, Monique C.

    1999-01-01

    Rainbow trout native to the McCloud River, California, USA (Oncorhynchus mykiss stonei) are thought to represent a relic, nonanadromous trout adapted to harsh, fragmented environments. These fish, commonly named McCloud River ‘redband’ trout, survive in their most primitive form in a small, spring-fed stream, Sheepheaven Creek, in the upper McCloud River drainage. Turn-of-the-century fisheries records document both coastal anadromous steelhead and freshwater resident trout within the McCloud River drainage. The phylogenetic position of the McCloud River redband trout within O. mykiss has been debated for over 50 years. Based on phenotypic evidence, these fish were first reported as ‘southern Sierra golden trout’ by Wales in 1939. Behnke (1970) considered them a relic subspecies of nonanadromous, fine-scaled trout. Allozyme and mitochondrial DNA evidence suggested a coastal lineage. In this study, we examined within- and among-basin genetic associations for Sheepheaven Creek redband trout using 11 microsatellite loci. Within-basin analyses supported unique genetic characteristics in Sheepheaven Creek’s trout in comparisons with other McCloud River rainbow trout. Microsatellite data supported significant independence between Sheepheaven Creek fish and hatchery rainbow trout. Inter-basin genetic distance analyses positioned Sheepheaven Creek fish with samples collected from Lassen Creek, a geographically proximate stream containing inland redband trout. California’s redband trout shared a close genetic association with Little Kern River golden trout (O.m. whitei) and isolated rainbow trout from Rio Santo Domingo, Baja, Mexico (O.m. nelsoni), suggesting a vicariant distribution of microsatellite diversity throughout the southern range of this species.

  1. Water velocity influences prey detection and capture by drift-feeding juvenile coho salmon (Oncorhynchus kisutch) and steelhead (Oncorhynchus mykiss irideus)

    Treesearch

    John J. Piccolo; Nicholas F. Hughes; Mason D. Bryant

    2008-01-01

    We examined the effects of water velocity on prey detection and capture by drift-feeding juvenile coho salmon (Oncorhynchus kisutch) and steelhead (sea-run rainbow trout,Oncorhynchus mykiss irideus) in laboratory experiments. We used repeated-measures analysis of variance to test the effects of velocity, species, and the velocity x species interaction on prey capture...

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

    USGS Publications Warehouse

    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.

  3. Evaluation of Head-of-Reservoir Conditions for Downstream Migration of Juvenile Chinook Salmon and Steelhead at Shasta Lake, California

    NASA Astrophysics Data System (ADS)

    Clancey, K. M.; Saito, L.; Svoboda, C.; Bender, M. D.; Hannon, J.; Hellmann, K. M.

    2015-12-01

    Since completion of Shasta Dam, migration of Chinook salmon and steelhead trout in the Sacramento River has been blocked, causing loss of spawning and rearing habitat. This has been a factor leading to population declines of these fish species over several decades. Winter-run Chinook salmon, spring-run Chinook salmon and steelhead trout are now listed under the Endangered Species Act. A habitat assessment of the tributaries upstream of Shasta Dam showed that the Sacramento and McCloud tributaries have suitable habitat for reintroduction of adult salmon and steelhead for spawning. Such reintroduction would require downstream passage of juvenile Chinook salmon and steelhead past Shasta Dam. To evaluate the possibility of collecting and transporting juvenile Chinook salmon and steelhead past Shasta Dam, a CE-QUAL-W2 model of Shasta Lake and the Sacramento River, McCloud River, Pit River and Squaw Creek tributaries was used to assess where and when conditions were favorable at head-of-reservoir locations upstream of proposed temperature curtains to collect juvenile fish. Head-of-reservoir is the zone of transition between the river and the upstream end of the reservoir. Criteria for evaluating locations suitable to collect these fish included water temperature and velocities in the Sacramento and McCloud tributaries. Model output was analyzed during months of downstream migration under dry, median and wet year conditions. Potential for proposed temperature curtains, anchored and floating, to improve conditions for fish migration was also evaluated with the CE-QUAL-W2 model. Use of temperature curtains to assist fish migration is a novel approach that to our knowledge has not previously been assessed for recovery of Chinook salmon and steelhead populations. Providing safe passage conditions is challenging, however the study findings may assist in formulation of a juvenile fish passage alternative that is suitable for Shasta Lake.

  4. Sediment Dynamics and Southern Steelhead Habitat (Oncorhynchus mykiss) in the Matilija Creek Watershed, Southern California

    NASA Astrophysics Data System (ADS)

    Minear, J. T.; Kondolf, G. M.

    2003-12-01

    Matilija Creek, one of two principal forks of the Ventura River, drains 142 km2 in the Transverse Ranges of southern California. Thanks to rapid tectonic uplift and weak clastic rocks, sediment yields exceed 1200 m3/km2 annually. Matilija Dam was built in 1947 with an initial capacity of 8 million m3 and is now nearly full of sediment. The dam is structurally unsafe, blocks anadromous fish migration, and is being considered for removal. The Ventura River has one of the southernmost runs of steelhead trout (Oncorhynchus mykiss), with an average of approximately 2,500 annually migrating up Matilija Creek before the dam was built. The high sediment yields and highly variable flow regime have raised questions about the interactions among high flows, sediment transfer from lower order tributaries to the third order channels used by the fish, and fish life history. Previous studies in Southern California have documented sediment yields (especially following debris flows and fires, and mostly in the San Gabriel Mountains), but the interaction of geomorphic processes and aquatic habitat in this highly episodic environment is not well understood. We used a combination of mapping and survey techniques, sediment traps, grain size analysis, lithologic analysis and scour rods to study intra-annual geomorphic processes and sediment dynamics affecting Southern Steelhead habitat in the Matilija Creek area in 16 study pools over the 2002 and 2003 flow seasons (dry and "normal", respectively) and found little sediment was deposited or scoured from pools. However, other processes not previously recognized significantly affected the steelhead habitat in the study pools including tufa cementation (carbonate deposition) and alder root growth in spawning gravels, as well as seasonal desiccation of some reaches. Removal of Matilija Dam will reopen suitable habitat to steelhead trout, but managers should recognize that habitat quality is likely to vary considerably from year

  5. Evaluation of the Reproductive Success of Wild and Hatchery Steelhead in Hatchery and Natural and Hatchery Environments : Annual Report for 2008.

    SciTech Connect

    Quinn, Thomas P.; Seamons, todd; Hauser, Lorenz

    2008-12-05

    This report summarizes the field, laboratory, and analytical work from December 2007 through November 2008 on a research project that investigates interactions and comparative reproductive success of wild and hatchery origin steelhead (Oncorhynchus mykiss) trout in Forks Creek, a tributary of the Willapa River in southwest Washington. First, we continued to successfully sample hatchery and wild (i.e., naturally spawned) adult and wild smolt steelhead at Forks Creek. Second, we revealed microsatellite genotype data for adults and smolts through brood year 2008. Finally, four formal scientific manuscripts were published in 2008 and two are in press, one is in revision andmore » two are in preparations.« less

  6. Invertebrates of Meadow Creek, Union County, Oregon, and their use as food by trout.

    Treesearch

    Carl E. McLemore; William R. Meehan

    1988-01-01

    From 1976 to 1980, invertebrates were collected three times each year from several reaches of Meadow Creek in eastern Oregon. Five sampling methods were used: benthos, drift, sticky traps, water traps, and fish stomachs. A total of 372 taxa were identified, of which 239 were used as food by rainbow trout (steelhead; Salmo gairdneri Richardson). Of...

  7. Linking habitat quality with trophic performance of steelhead along forest gradients in the South Fork Trinity River Watershed, California

    USGS Publications Warehouse

    McCarthy, Sarah G.; Duda, Jeffrey J.; Emlen, John M.; Hodgson, Garth R.; Beauchamp, David A.

    2009-01-01

    We examined invertebrate prey, fish diet, and energy assimilation in relation to habitat variation for steelhead Oncorhynchus mykiss (anadromous rainbow trout) and rainbow trout in nine low-order tributaries of the South Fork Trinity River, northern California. These streams spanned a range of environmental conditions, which allowed us to use bioenergetics modeling to determine the relative effects of forest cover, stream temperature, season, and fish age on food consumption and growth efficiency. Evidence of seasonal shifts in reliance on aquatic versus terrestrial food sources was detected among forest cover categories and fish ages, although these categories were not robust indicators of O. mykiss condition and growth efficiency. Consumption estimates were generally less than 20% of maximum consumption, and fish lost weight in some streams during summer low-flow conditions when stream temperatures exceeded 15°C. Current 100-year climate change projections for California threaten to exacerbate negative growth patterns and may undermine the productivity of this steelhead population, which is currently not listed as endangered or threatened. To demonstrate the potential effect of global warming on fish growth, we ran three climate change scenarios in two representative streams. Simulated temperature increases ranging from 1.4°C to 5.5°C during the summer and from 1.5°C to 2.9C during the winter amplified the weight loss; estimated average growth for age-1 fish was 0.4–4.5 times lower than normal (low to high estimated temperature increase) in the warm stream and 0.05–0.8 times lower in the cool stream. We conclude that feeding rate and temperature during the summer currently limit the growth and productivity of steelhead and rainbow trout in low-order streams in the South Fork Trinity River basin and predict that climate change will have detrimental effects on steelhead growth as well as on macroinvertebrate communities and stream ecosystems in general.

  8. Toxicity of hydrogen peroxide treatments to rainbow trout eggs

    USGS Publications Warehouse

    Gaikowski, M.P.; Rach, J.J.; Olson, J.J.; Ramsay, R.T.

    1998-01-01

    Hydrogen peroxide treatments of 0, 500, 1,000, and 3,000 I?L/L, concentrations that were multiples of the Low Regulatory Priority limit of 500 I?L/L, were administered for 15 min every weekday (Mondaya??Friday) to eggs of rainbow trout Oncorhynchus mykiss and steelhead (anadromous rainbow trout) to determine the margin of safety existing for standard egg treatments. All untreated and treated eggs remained free of fungal infection throughout incubation. Hydrogen peroxide treatment reduced the mean percent hatch of rainbow trout eggs by 1.4a??5.9% among those treated at 500 I?L/L, 6.8a??15.4% among those treated at 1,000 I?L/L, and 13.2a??25.3% among those treated at 3,000 I?L/L. Mean percent hatch of rainbow trout eggs treated at 1,000 I?L H2O2/L was 7% lower than that for eggs treated at 500 I?L H2O2/L. Mean percent hatch of Skamania strain steelhead was significantly reduced by hydrogen peroxide treatment, whereas the mean percent hatch of Ganaraska strain steelhead was similar to the mean percent hatch of rainbow trout eggs. Daily percent mortality of rainbow trout eggs increased significantly from day 6 to day 10 (78a??135 daily temperature units, DTUsA?C) of incubation. Discontinuing hydrogen peroxide treatments to Skamania strain steelhead eggs from day 7 to day 11 (78a??105 DTUsA?C) of incubation significantly increased the probability of eggs reaching the eyed egg stage. The mean percent hatch of rainbow trout eggs treated with hydrogen peroxide at concentrations up to 1,000 I?L/L may be increased if no treatments are administered between 70 and 140 DTUsA?C. Mortality of sac fry was not observed at hydrogen peroxide concentrations of 1,000 I?L/L or lower. Fish culturists should be aware that other species or strains may be more sensitive than rainbow trout. Other species and strains should be initially treated with hydrogen peroxide at 500 I?L/L until monitoring of egg mortality identifies the presence or absence of a sensitive period.

  9. Size-conditional smolting and the response of Carmel River steelhead to two decades of conservation efforts

    PubMed Central

    Lopez Arriaza, Juan; Urquhart, Kevan; Mangel, Marc

    2017-01-01

    Threshold effects are common in ecosystems and can generate counterintuitive outcomes in management interventions. A threshold effect proposed for steelhead trout (Oncorhynchus mykiss) is size-conditional smolting and marine survival. Steelhead are anadromous, maturing in the ocean but migrating to freshwater to spawn, where their offspring reside for one or more years before smolting—physiologically transforming to a saltwater form—and migrating to the ocean. In conditional smolting, juveniles transform only if growth exceeds a threshold body size prior to migration season, and subsequent marine survival correlates with size at ocean entry. Conditional smolting suggests that efforts to improve freshwater survival of juveniles may reduce smolt success if they increase competition and reduce growth. Using model-selection techniques, we asked if this effect explained declining numbers of adult Carmel River steelhead. This threatened population has been the focus of two decades of habitat restoration, as well as active translocation and captive-rearing of juveniles stranded in seasonally dewatered channels. In the top-ranked model selected by information-theoretic criteria, adult decline was linked to reduced juvenile growth rates in the lower river, consistent with the conditional smolting hypothesis. According to model inference, since 2005 most returning adult steelhead were captively-reared. However, a lower-ranked model without conditional smolting also had modest support, and suggested a negative effect of captive rearing. Translocations of juvenile fish to perennial reaches may have reduced the steelhead run slightly by raising competition, but this effect is confounded in the data with effects of river flow on growth. Efforts to recover Carmel River steelhead will probably be more successful if they focus on conditions promoting rapid growth in the river. Our analysis clearly favored a role for size-conditional smolting and marine survival in the decline

  10. Behavior and movement of adult summer steelhead following collection and release, lower Cowlitz River, Washington, 2012--2013

    USGS Publications Warehouse

    Kock, Tobias J.; Liedtke, Theresa L.; Ekstrom, Brian K.; Rondorf, Dennis W.; Gleizes, Chris; Dammers, Wolf; Gibson, Scott; Murphy, Jamie

    2013-01-01

    radio-tags from recycled steelhead were detected near popular fishing areas, and 2 percent of the radio-tagged steelhead were never detected during the study period. We suspect that a large proportion of these fish may have been harvested and not reported, or died.Detection patterns of radio-tagged steelhead showed that most fish (82 percent) moved upstream from the release site and were detected at the Trout Hatchery and the Barrier Dam sites. The median time from release to detection at these sites was 3.7 d and many of these fish made multiple trips between the two sites. Nearly one-third (29 percent) of the recycled steelhead that were detected at the Trout Hatchery and the Barrier Dam made at least two trips between the sites and some fish made as many as six trips. Radio-tagged fish that remained in the lower Cowlitz River during the spawning period (December 2012–January 2013) were observed in the river reach between the mouth of Ostrander Creek (river mile 10) and the Trout Hatchery (river mile 44).During this study, we collected data on opercle punch regrowth rates to understand the temporal effectiveness of this marking technique. We took opercle measurements for a total of 190 fish during the study. Fresh opercle punches were measured for 63 fish at the time of marking, and the remaining 127 fish were measured when fish returned to the hatchery. We determined that opercle punches remained open for about 30 d. The holes appeared to regrow slowly in the first 20 d after marking, but regrowth accelerated during the 20–30 d post-marking period. After 30 d, all opercle punches that we observed had completely closed due to tissue regrowth.Our study showed that a large proportion (68 percent) of the recycled steelhead were removed from the lower Cowlitz River. These fish primarily entered the hatchery or were caught by anglers within 14 d of release, which suggests that they present minimal risk to wild fish in the system. However, the remaining fish (32 percent

  11. Monitoring and Evaluation of Smolt Migration in the Columbia Basin : Volume IX : Evaluation of the 2001 Predictions of the Run-Timing of Wild and Hatchery-Reared Migrant Salmon and Steelhead Trout Migrating to Lower Granite, Rock Island, McNary, and John Day Dams using Program RealTime.

    SciTech Connect

    Burgess, Caitlin; Skalski, John R.

    2001-12-01

    Program RealTime provided tracking and forecasting of the 2001 inseason outmigration via the internet for eighteen PIT-tagged stocks of wild salmon and steelhead to Lower Granite and/or McNary dams and eleven passage-indexed stocks to Rock Island, McNary, or John Day dams. Nine of the PIT-tagged stocks tracked this year were new to the project. Thirteen ESUs of wild subyearling and yearling chinook salmon and steelhead, and one ESU of hatchery-reared sockeye salmon were tracked and forecasted to Lower Granite Dam. Eight wild ESUs of subyearling and yearling chinook salmon, sockeye salmon and steelhead were tracked to McNary Dam for themore » first time this year. Wild PIT-tagged ESUs tracked to Lower Granite Dam included yearling spring/summer chinook salmon release-recovery stocks (from Bear Valley Creek, Catherine Creek, Herd Creek, Imnaha River, Johnson Creek, Lostine River, Minam River, South Fork Salmon River, Secesh River, and Valley Creek), PIT-tagged wild runs-at-large of yearling chinook salmon and steelhead, and a PIT-tagged stock of subyearling fall chinook salmon. The stock of hatchery-reared PIT-tagged summer-run sockeye salmon smolts outmigrating to Lower Granite Dam, consisted this year of a new stock of fish from Alturas Lake Creek, Redfish Lake Creek Trap and Sawtooth Trap. The passage-indexed stocks, counted using FPC passage indices, included combined wild- and hatchery-reared runs-at-large of subyearling and yearling chinook, coho, and sockeye salmon, and steelhead migrating to Rock Island and McNary dams, and, new this year, combined wild and hatchery subyearling chinook salmon to John Day Dam. Unusual run-timing and fish passage characteristics were observed in this low-flow, negligible-spill migration year. The period for the middle 80% of fish passage (i.e., progress from the 10th to the 90th percentiles) was unusually short for nine out of ten PIT-tagged yearling spring/summer chinook salmon stocks tracked to Lower Granite Dam. It was the

  12. Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2005-2006 Annual Report.

    SciTech Connect

    Branstetter, Ryan; Whiteaker, John; Hatch, Douglas R.

    2006-12-01

    Iteroparity, the ability to repeat spawn, is a natural life history strategy that is expressed by some species from the family Salmonidae. Estimated rates of repeat spawning for post-development Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the current expression of repeat spawning rates using fish culturing methods could be a viable technique to assist the recovery of depressed steelhead populations, and could help reestablishmore » this naturally occurring life history trait. Reconditioning is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to reinitiate feeding, growth, and redevelop mature gonads. Reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia River Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To test kelt steelhead reconditioning as a potential recovery tool, wild emigrating steelhead kelts were placed into one of four study groups (in river release, direct capture and transport, short-term reconditioning, or long-term reconditioning). Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Monitoring Facility (CJMF, located on the Yakima River at river kilometer 75.6) from 7 March to 8 June 2006. In total, 348 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 17.0% (348 of 2,002) of the entire 2005-2006 Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. Steelhead kelts were reconditioned in 20-foot circular tanks, and fed freeze-dried krill initially

  13. Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2005 Annual Report.

    SciTech Connect

    Branstetter, Ryan; Whiteaker, John; Hatch, Douglas R.

    2006-01-01

    Iteroparity, the ability to repeat spawn, is a natural life history strategy that is expressed by some species from the family Salmonidae. Estimated rates of repeat spawning for post-development Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the current expression of repeat spawning rates using fish culturing methods could be a viable technique to assist the recovery of depressed steelhead populations, and could help reestablishmore » this naturally occurring life history trait. Reconditioning is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to reinitiate feeding, growth, and redevelop mature gonads. Reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia River Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To test kelt steelhead reconditioning as a potential recovery tool, wild emigrating steelhead kelts were placed into one of four study groups (in river release, direct capture and transport, short-term reconditioning, or long-term reconditioning). Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Monitoring Facility (CJMF, located on the Yakima River at river kilometer 75.6) from 11 March to 23 June 2005. In total, 519 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 15.0% (519 of 3,451) of the entire 2004-2005 Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. Steelhead kelts were reconditioned in 20-foot circular tanks, and fed freeze-dried krill initially

  14. Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2003 Annual Report.

    SciTech Connect

    Hatch, Douglas R.; Branstetter, Ryan; Blodgett, Joe

    2004-03-01

    Repeat spawning is a life history strategy that is expressed by some species from the family Salmonidae. Rates of repeat spawning for post-development Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the natural expression of historical repeat spawning rates using fish culturing methods could be a viable technique to assist the recovery of depressed steelhead populations. Reconditioning is the process of culturing post-spawned fish (kelts)more » in a captive environment until they are able to reinitiate feeding, growth, and redevelop mature gonads. Kelt reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To test kelt steelhead reconditioning as a potential recovery tool, we captured wild emigrating steelhead kelts from the Yakima River and evaluated reconditioning (short and long-term) success and diet formulations at Prosser Hatchery on the Yakima River. Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Monitoring Facility (CJMF, located on the Yakima River at river kilometer 75.6) from 12 March to 28 May 2003. In total, 690 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 30.8% (690 of 2,235) of the entire 2002-2003 Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. All steelhead kelts were reconditioned in circular tanks, fed freeze-dried krill and received hw-wiegandt multi vit dietary supplement; long-term steelhead kelts also received Moore-Clark pellets

  15. Steelhead Supplementation Studies; Steelhead Supplementation in Idaho Rivers, Annual Report 2002.

    SciTech Connect

    Byrne, Alan

    2003-03-01

    The Steelhead Supplementation Study (SSS) has two broad objectives: (1) investigate the feasibility of supplementing depressed wild and natural steelhead populations using hatchery populations, and (2) describe the basic life history and genetic characteristics of wild and natural steelhead populations in the Salmon and Clearwater Basins. Idaho Department of Fish and Game (IDFG) personnel stocked adult steelhead from Sawtooth Fish Hatchery into Frenchman and Beaver creeks and estimated the number of age-1 parr produced from the outplants since 1993. On May 2, 2002, both Beaver and Frenchman creeks were stocked with hatchery adult steelhead. A SSS crew snorkeled the creeksmore » in August 2002 to estimate the abundance of age-1 parr from brood year (BY) 2001. I estimated that the yield of age-1 parr per female stocked in 2001 was 7.3 and 6.7 in Beaver and Frenchman creeks, respectively. SSS crews stocked Dworshak hatchery stock fingerlings and smolts from 1993 to 1999 in the Red River drainage to assess which life stage produces more progeny when the adults return to spawn. In 2002, Clearwater Fish Hatchery personnel operated the Red River weir to trap adults that returned from these stockings. Twelve PIT-tagged adults from the smolt releases and one PIT-tagged adult from fingerling releases were detected during their migration up the mainstem Columbia and Snake rivers, but none from either group were caught at the weir. The primary focus of the study has been monitoring and collecting life history information from wild steelhead populations. An adult weir has been operated annually since 1992 in Fish Creek, a tributary of the Lochsa River. The weir was damaged by a rain-on-snow event in April 2002 and although the weir remained intact, some adults were able to swim undetected through the weir. Despite damage to the weir, trap tenders captured 167 adult steelhead, the most fish since 1993. The maximum likelihood estimate of adult steelhead escapement was 242. A

  16. Effects of hatchery fish density on emigration, growth, survival, and predation risk of natural steelhead parr in an experimental stream channel

    USGS Publications Warehouse

    Tatara, Christopher P.; Riley, Stephen C.; Berejikian, Barry A.

    2011-01-01

    Hatchery supplementation of steelhead Oncorhynchus mykiss raises concerns about the impacts on natural populations, including reduced growth and survival, displacement, and increased predation. The potential risks may be density dependent.We examined how hatchery stocking density and the opportunity to emigrate affect the responses of natural steelhead parr in an experimental stream channel and after 15 d found no density-dependent effects on growth, emigration, or survival at densities ranging from 1-6 hatchery parr/m2. The opportunity for steelhead parr to emigrate reduced predation by coastal cutthroat trout O. clarkii clarkii on both hatchery and natural steelhead parr. The cutthroat trout exhibited a type-I functional response (constant predation rate with increased prey density) for the hatchery and composite populations. In contrast, the predation rate on natural parr decreased as hatchery stocking density increased. Supplementation with hatchery parr at any experimental stocking density reduced the final natural parr density. This decline was explained by increased emigration fromthe supplemented groups. Natural parr had higher mean instantaneous growth rates than hatchery parr. The proportion of parr emigrating decreased as parr size increased over successive experimental trials. Smaller parr had lower survival and suffered higher predation. The final density of the composite population, a measure of supplementation effectiveness, increased with the hatchery steelhead stocking rate. Our results indicate that stocking larger hatchery parr (over 50 d postemergence) at densities within the carrying capacity would have low short-term impact on the growth, survival, and emigration of natural parr while increasing the density of the composite population; in addition, a stocking density greater than 3 fish/m2 might be a good starting point for the evaluation of parr stocking in natural streams.

  17. Evaluation of the behavior and movement of adult summer steelhead in the lower Cowlitz River, Washington, following collection and release, 2013-2014

    USGS Publications Warehouse

    Kock, Tobias J.; Liedtke, Theresa L.; Ekstrom, Brian K.; Gleizes, Chris; Dammers, Wolf

    2014-01-01

    of the fish were harvested by anglers, and 32 percent of the fish were not known to have been removed from the river. During October–December 2012, only 9 percent of the radio-tagged steelhead remained in the lower Cowlitz River and none of these fish entered tributaries monitored by fixed-telemetry sites. The second year of the evaluation was conducted during 2013–2014. A total of 502 steelhead were recycled during June–August and releases were conducted weekly with group sizes that ranged from 30 to 76 fish. Results from 2013–2014 were similar to results from 2012–2013. Fifty percent (251 fish) of the recycled steelhead returned to the hatchery, 20 percent (100 fish) were harvested by anglers, and 30 percent (151 fish) were unaccounted for. The median elapsed time from release to hatchery return was 13 days, and the median elapsed time from release to capture by an angler was 11 days. The percentage of unaccounted-for steelhead in the general population was moderately high (30 percent), but detection records of radio-tagged fish suggest that few recycled steelhead were present in the lower Cowlitz River during the spawning period. A total of 109 steelhead were radio-tagged during 2013–2014, and most of these fish (88 percent) moved upstream following release and entered the Trout Hatchery–Salmon Hatchery reach (river miles 44–51). The median elapsed time from release to reach entry was 4.6 days (range of 0.5–65.5 days). After fish entered this reach, they spent a considerable amount of time near the Cowlitz Trout Hatchery (median residence time of 16.7 hours) or Cowlitz Salmon Hatchery (median residence time of 146.3 hours), or they moved back and forth between these two sites. Thirty radio-tagged steelhead made at least two trips between the sites and some fish made as many as seven trips. Detection records showed that 61 percent (66 fish) of the radio-tagged fish returned to the hatchery reach and 21 percent (23 fish) of the fish were captured

  18. Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2001 Annual Report.

    SciTech Connect

    Hatch, Douglas R.; Anders, Paul J., Evans, Allen F.

    2002-12-01

    Repeat spawning is a life history strategy that is expressed by some species from the family Salmonidae. Rates of repeat spawning for post-development Columbia River steelhead (Oncorhynchus mykiss) populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are artificially and in some cases severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the natural expression of historical repeat spawning rates using fish culturing means could be a viable technique to assist the recovery of depressed steelhead populations. Reconditioning is the processmore » of culturing post-spawned fish (kelts) in a captive environment until they are able to reinitiate feeding, growth, and again develop mature gonads. Kelt reconditioning techniques were initially developed for Atlantic salmon (Salmo salar) and sea-trout (S. trutta). The recent Endangered Species Act listing of many Columbia Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To address recovery, we captured wild emigrating steelhead kelts from the Yakima River and tested reconditioning and the effects of several diet formulations on its success at Prosser Hatchery on the Yakama Reservation. Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Evaluation Facility (CJEF, located at Yakima River kilometer 48) from 12 March to 5 July 2001. Kelts were reconditioned in circular tanks and fed a mixed diet of starter paste, adult sized trout pellets, and freeze-dried krill. Formalin was used to control outbreaks of fungus and we tested the use of Ivermectin{trademark}to control internal parasites (e.g., Salmincola spp.). Surviving specimens were released for natural spawning in two groups on 15 November 2001 and 18 January 2002. Overall success of the reconditioning process was

  19. Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2002 Annual Report.

    SciTech Connect

    Hatch, Douglas R.; Branstetter, Ryan; Blodgett, Joe

    2003-07-01

    Repeat spawning is a life history strategy that is expressed by some species from the family Salmonidae. Rates of repeat spawning for post-development Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the natural expression of historical repeat spawning rates using fish culturing means could be a viable technique to assist the recovery of depressed steelhead populations. Reconditioning is the process of culturing post-spawned fish (kelts)more » in a captive environment until they are able to reinitiate feeding, growth, and again develop mature gonads. Kelt reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To test kelt steelhead reconditioning as a potential recovery tool, we captured wild emigrating steelhead kelts from the Yakima River and evaluated reconditioning (short and long-term) success and diet formulations at Prosser Hatchery on the Yakima River. Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Evaluation Facility (CJEF, located at Yakima River kilometer 48) from March 12 to June 13, 2002. In total, 899 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 19.8% (899 of 4,525) of the entire 2001-2002 Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. Kelts were reconditioned in circular tanks and were fed freeze-dried krill, Moore-Clark pellets, altered Moore-Clark pellets (soaked in krill extract and dyed), or a combination of the altered Moore

  20. Movement of resident rainbow trout transplanted below a barrier to anadromy

    USGS Publications Warehouse

    Wilzbach, Margaret A.; Ashenfelter, Mark J.; Ricker, Seth J.

    2012-01-01

    We tracked the movement of resident coastal rainbow trout Oncorhynchus mykiss irideus that were experimentally transplanted below a migration barrier in a northern California stream. In 2005 and 2006, age-1 and older rainbow trout were captured above a 5-m-high waterfall in Freshwater Creek and individually marked with passive integrated transponder tags. Otolith microchemistry confirmed that the above-barrier trout were the progeny of resident rather than anadromous parents, and genetic analysis indicated that the rainbow trout were introgressed with cutthroat trout O. clarkii. At each of three sampling events, half of the tagged individuals (n = 22 and 43 trout in 2005 and 2006, respectively) were released 5 km downstream from the waterfall (approximately 10 km upstream from tidewater), and an equal number of tagged individuals were released above the barrier. Tagged individuals were subsequently relocated with stationary and mobile antennae or recaptured in downstream migrant traps, or both, until tracking ceased in October 2007. Most transplanted individuals remained within a few hundred meters of their release location. Three individuals, including one rainbow trout released above the waterfall, were last detected in the tidally influenced lower creek. Two additional tagged individuals released above the barrier were found alive in below-barrier reaches and had presumably washed over the falls. Two of seven tagged rainbow trout captured in downstream migrant traps had smolted and one was a presmolt. The smoltification of at least some individuals, coupled with above-barrier "leakage" of fish downstream, suggests that above-barrier resident trout have the potential to exhibit migratory behavior and to enter breeding populations of steelhead (anadromous rainbow trout) within the basin.

  1. Steelhead Supplementation in Idaho Rivers : 2001 Project Progress Report.

    SciTech Connect

    Byrne, Alan

    2002-03-01

    In 2001, Idaho Department of Fish and Game (IDFG) continued an assessment of the Sawtooth Hatchery steelhead Oncorhynchus mykiss stock to reestablish natural populations in Beaver and Frenchman creeks in the upper Salmon River. Crews stocked both streams with 20 pair of hatchery adults, and I estimated the potential smolt production from the 2000 adult outplants. n the Red River drainage, IDFG stocked Dworshak hatchery stock fingerlings and smolts from 1993 to 1999 to assess which life stage produces more progeny when the adults return to spawn. In 2001, IDFG operated the Red River weir to trap adults that returnedmore » from these stockings, but none were caught from either group. Wild steelhead populations in the Lochsa and Selway river drainages were assessed and the chinook salmon Oncorhynchus tshawytscha escapement was enumerated in Fish Creek. I estimated that 75 wild adult steelhead and 122 adult chinook salmon returned to Fish Creek in 2001. I estimated that slightly more than 30,000 juvenile steelhead migrated out of Fish Creek. This is the largest number of steelhead to migrate out of Fish Creek in a single year since I began estimating the yearly migration in 1994. Juvenile steelhead densities in Lochsa and Selway tributaries were somewhat higher in 2001 than those observed in 2000. Crews from IDFG collected over 4,800 fin samples from wild steelhead in 74 streams of the Clearwater, Snake, and Salmon river drainages and from five hatchery stocks during the summer of 2000 for a DNA analysis to assess Idaho's steelhead stock structure. The DNA analysis was subcontracted to Dr. Jennifer Nielsen, Alaska Biological Science Center, Anchorage. Her lab developed protocols to use for the analysis in 2001 and is continuing to analyze the samples. Dr. Nielsen plans to have the complete set of wild and hatchery stocks analyzed in 2002.« less

  2. Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2004 Annual Report.

    SciTech Connect

    Hatch, Douglas R.; Branstetter, Ryan; Whiteaker, John

    2004-11-01

    Iteroparity, the ability to repeat spawn, is a life history strategy that is expressed by some species from the family Salmonidae. Rates of repeat spawning for post-development Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the expression of historical repeat spawning rates using fish culturing methods could be a viable technique to assist the recovery of depressed steelhead populations, and could help reestablish this naturallymore » occurring life history trait. Reconditioning is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to reinitiate feeding, growth, and redevelop mature gonads. Kelt reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia River Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To test kelt steelhead reconditioning as a potential recovery tool, wild emigrating steelhead kelts were placed into one of three study groups (direct capture and transport, short-term reconditioning, or long-term reconditioning). Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Monitoring Facility (CJMF, located on the Yakima River at river kilometer 75.6) from 15 March to 21 June 2004. In total, 842 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 30.5% (842 of 2,755) of the entire 2003-2004 Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. All steelhead kelts were reconditioned in 20-foot circular tanks, and fed freeze-dried krill initially or for the duration of

  3. 77 FR 64316 - Endangered and Threatened Species; Recovery Plan South-Central California Coast Steelhead...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-19

    ... and Threatened Species; Recovery Plan South-Central California Coast Steelhead Distinct Population... Coast (SCCCS) (Oncorhynchus mykiss) Distinct Population (DPS). NMFS is soliciting review and comment... plan development. NMFS is hereby soliciting relevant information on SCCC Steelhead DPS populations and...

  4. Steelhead Supplementation in Idaho Rivers, 2000 Annual Report.

    SciTech Connect

    Byrne, Alan

    2001-01-01

    In 2000, we continued our assessment of the Sawtooth Hatchery steelhead stock to reestablish natural populations in Beaver and Frenchman creeks in the upper Salmon River. We stocked both streams with 15 pair of hatchery adults and estimated the potential smolt production from the 1999 outplant. I estimated that about nine smolts per female could be produced in both streams from the 1999 outplant. The smolt-to-adult return would need to exceed 20% to return two adults at this level of production. In the Red River drainage, we stocked Dworshak hatchery stock fingerlings and smolts, from 1993 to 1999, to assessmore » which life-stage produces more progeny when the adults return to spawn. In 2000, we operated the Red River weir to trap adults that returned from these stockings, but none were caught from either group. We continued to monitor wild steelhead populations in the Lochsa and Selway river drainages. We estimated that 26 wild adult steelhead returned to Fish Creek. This is the lowest adult escapement we have documented (when the weir was intact all spring) since we began monitoring Fish Creek in 1992. I estimated that nearly 25,000 juvenile steelhead migrated out of Fish Creek this year. Juvenile steelhead densities in Lochsa and Selway tributaries were similar to those observed in 1999. In 2000, we obtained funding for a DNA analysis to assess Idaho's steelhead stock structure. We collected fin samples from wild steelhead in 70 streams of the Clearwater, Snake, and Salmon River drainages and from our five hatchery stocks. The DNA analysis was subcontracted to Dr. Jennifer Nielsen, Alaska Biological Science Center, Anchorage, and will be completed in 2001.« less

  5. Children's Fitness. Managing a Running Program.

    ERIC Educational Resources Information Center

    Hinkle, J. Scott; Tuckman, Bruce W.

    1987-01-01

    A running program to increase the cardiovascular fitness levels of fourth-, fifth-, and sixth-grade children is described. Discussed are the running environment, implementation of a running program, feedback, and reinforcement. (MT)

  6. Habitat-dependent interactions between two size-classes of juvenile steelhead in a small stream

    Treesearch

    Bret C. Harvey; Rodney J. Nakamoto

    1997-01-01

    Abstract - The presence of small steelhead (Oncorhynchus mykiss; averaging 55 mm fork length) influenced the growth of larger juvenile steelhead (90 mm fork length) during a 6-week experiment conducted in North Fork Caspar Creek, California, in summer 1994. In fenced replicate deep stream sections in this small stream, growth of the larger steelhead was greater in...

  7. Temperature-dependent interactions between juvenile steelhead and Sacramento pikeminnow in laboratory streams

    Treesearch

    Carl D. Reese; Bret C. Harvey

    2002-01-01

    Abstract - We examined the temperature dependence of interactions between juvenile steelhead 'Oncorhynchus mykiss' and juvenile Sacramento pikeminnow 'Ptychocheilus grandis' in laboratory streams. Growth of dominant steelhead in water 20-23 degree C was reduced by more than 50% in trials with Sacramento pikeminnow compared with trials with steelhead...

  8. Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2000 Annual Report.

    SciTech Connect

    Evans, Allen F.; Beaty, Roy E.; Hatch, Douglas R.

    2001-12-01

    Repeat spawning is a life history strategy that is expressed by some species from the family salmonidae. Natural rates of repeat spawning for Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. Increasing this repeat spawning rate using fish culture techniques could assist the recovery of depressed steelhead populations. Reconditioning is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to grow and develop mature gonads. Kelt reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia Basin steelheadmore » populations has prompted interest in developing reconditioning methods for local populations. The primary purpose of this project in 2000 was to test the general feasibility of collecting, feeding, and treating steelhead kelts in a captive environment. Steelhead kelts were collected from the Yakima River at the Chandler Juvenile Evaluation Facility (Rkm 48) from 12 March to 13 June 2000. Kelts were reconditioned at adjacent Prosser Hatchery in both rectangular and circular tanks and fed a mixed diet of starter paste, adult sized trout pellets, and freeze-dried krill. Formalin was used to control outbreaks of fungus, and we tested the use of ivermectin to control internal parasites (e.g., Salmincola spp.). Some the kelts that died during the reconditioning process were analyzed via pathology and gonad histology to ascertain the possible cause of death and to describe their reproductive development at the time of death. All surviving specimens were released for natural spawning on 12 December 2000. Overall success of the reconditioning process was based on the proportion of fish that survived captivity, gained weight, and on the number of fish that successfully underwent gonadal recrudescence. Many of the reconditioned kelts were radio tagged to assess their spawning migration

  9. Idaho Steelhead Monitoring and Evaluation Studies : Annual Progress Report 2007.

    SciTech Connect

    Copeland, Timothy; Putnam, Scott

    2008-12-01

    The goal of Idaho Steelhead Monitoring and Evaluation Studies is to collect monitoring data to evaluate wild and natural steelhead populations in the Clearwater and Salmon river drainages. During 2007, intensive population data were collected in Fish Creek (Lochsa River tributary) and Rapid River (Little Salmon River tributary); extensive data were collected in other selected spawning tributaries. Weirs were operated in Fish Creek and Rapid River to estimate adult escapement and to collect samples for age determination and genetic analysis. Snorkel surveys were conducted in Fish Creek, Rapid River, and Boulder Creek (Little Salmon River tributary) to estimate parr density.more » Screw traps were operated in Fish Creek, Rapid River, Secesh River, and Big Creek to estimate juvenile emigrant abundance, to tag fish for survival estimation, and to collect samples for age determination and genetic analysis. The estimated wild adult steelhead escapement in Fish Creek was 81 fish and in Rapid River was 32 fish. We estimate that juvenile emigration was 24,127 fish from Fish Creek; 5,632 fish from Rapid River; and 43,674 fish from Big Creek. The Secesh trap was pulled for an extended period due to wildfires, so we did not estimate emigrant abundance for that location. In cooperation with Idaho Supplementation Studies, trap tenders PIT tagged 25,618 steelhead juveniles at 18 screw trap sites in the Clearwater and Salmon river drainages. To estimate age composition, 143 adult steelhead and 5,082 juvenile steelhead scale samples were collected. At the time of this report, 114 adult and 1,642 juvenile samples have been aged. Project personnel collected genetic samples from 122 adults and 839 juveniles. We sent 678 genetic samples to the IDFG Eagle Fish Genetics Laboratory for analysis. Water temperature was recorded at 37 locations in the Clearwater and Salmon river drainages.« less

  10. Steelhead Kelt Reconditioning and Reproductive Success, 2008 Annul Report.

    SciTech Connect

    Hatch, Douglas R.

    2009-04-02

    Iteroparity, the ability to repeat spawn, is a natural life history strategy that is expressed by some species from the family Salmonidae. Current rates of observed steelhead Oncorhynchus mykiss iteroparity rates in the Columbia River Basin are severely depressed due to anthropogenic development which includes operation of the hydropower system and other habitat degradations. Artificial reconditioning, which is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to reinitiate feeding, growth, and redevelop mature gonads, is evaluated in this study as method to restore depressed steelhead populations. To test the efficacy of steelhead keltmore » reconditioning as a management and recovery tool different scenarios were investigated ranging from very low intensity (collect and transport fish) to high intensity (collect and feed fish in captivity until rematuration). Examinations of gamete and progeny viability were performed for first-time spawners and reconditioned kelt steelhead. We have continued to examine reproductive success of reconditioned kelt steelhead in Omak Creek using microsatellite loci to perform parentage analysis on juvenile O. mykiss . The groundwork has also begun on developing a genetic analysis of the Yakima subbasin in order to determine steelhead kelt contribution by utilizing parentage analysis on a larger scale. A research and study plan has been developed cooperatively with the University of Idaho to determine the feasibility of steelhead kelt reconditioning program in the Snake River Basin. Analysis of management scenarios indicated that while no-term and short-term reconditioned kelts continue to perform well outmigrating to the ocean but returns from these groups have been low ranging from 0-12% during 2002-2008. Survival (56%) of fish in the long-term treatment in 2008 was the highest we have observed in this project. Analyzing the three different management scenarios within the Yakima River

  11. Hood River Steelhead Genetics Study; Relative Reproductive Success of Hatchery and Wild Steelhead in the Hood River, Final Report 2002-2003.

    SciTech Connect

    Blouin, Michael

    2003-05-01

    There is a considerable interest in using hatcheries to speed the recovery of wild populations. The Bonneville Power Administration (BPA), under the authority of the Northwest Power Planning Act, is currently funding several hatchery programs in the Columbia Basin as off-site mitigation for impacts to salmon and steelhead caused by the Columbia River federal hydropower system. One such project is located on the Hood River, an Oregon tributary of the Columbia. These hatchery programs cost the region millions of dollars. However, whether such programs actually improve the status of wild fish remains untested. The goal of this project was tomore » evaluate the effectiveness of the Hood River hatchery program as required by the Northwest Power Planning Council Fish and Wildlife Program, by the Oregon Plan for Coastal Salmonids, by NMFS ESA Section 4(d) rulings, and by the Oregon Department of Fish and Wildlife (ODFW) Wild Fish Management Policy (OAR 635-07-525 through 529) and the ODFW Hatchery Fish Gene Resource Management Policy (OAR 635-07-540 through 541). The Hood River supports two populations of steelhead, a summer run and a winter run. They spawn only above the Powerdale Dam, which is a complete barrier to all salmonids. Since 1991 every adult passed above the dam has been measured, cataloged and sampled for scales. Therefore, we have a DNA sample from every adult steelhead that went over the dam to potentially spawn in the Hood River from 1991 to the present. Similar numbers of hatchery and wild fish have been passed above the dam during the last decade. During the 1990's 'old' domesticated hatchery stocks of each run (multiple generations in the hatchery, out-of-basin origin; hereafter H{sub old}) were phased out, and conservation hatchery programs were started for the purpose of supplementing the two wild populations (hereafter 'new' hatchery stocks, H{sub new}). These samples gave us the unprecedented ability to estimate, via microsatellite-based pedigree

  12. Genetic investigation of natural hybridization between rainbow and coastal cutthroat trout in the copper River Delta, Alaska

    USGS Publications Warehouse

    Williams, I.; Reeves, G.H.; Graziano, S.L.; Nielsen, J.L.

    2007-01-01

    Molecular genetic methods were used to quantify natural hybridization between rainbow trout Oncorhynchus mykiss or steelhead (anadromous rainbow trout) and coastal cutthroat trout O. clarkii clarkii collected in the Copper River delta, Southeast Alaska. Eleven locations were sampled to determine the extent of hybridization and the distribution of hybrids. Four diagnostic nuclear microsatellite loci and four species-specific simple sequence repeat markers were used in combination with restriction fragment length polymorphism analyses of NADH dehydrogenase 5/6 (ND5/6) mitochondrial DNA (mtDNA) to investigate the genetic structure of trout from both species and identify putative interspecific hybrids. Hybrids were found in 7 of the 11 streams sampled in the Copper River delta, the extent of hybridization across all streams varying from 0% to 58%. Hybrid trout distribution appeared to be nonrandom, most individuals of mixed taxonomic ancestry being detected in streams containing rainbow trout rather than in streams containing coastal cutthroat trout. Genotypic disequilibrium was observed among microsatellite loci in populations with high levels of hybridization. We found no significant correlation between unique stream channel process groups and the number of hybrid fish sampled. Eighty-eight percent of fish identified as first-generation hybrids (F1) in two populations contained coastal cutthroat trout mtDNA, suggesting directionality in hybridization. However, dominance of coastal cutthroat trout mtDNA was not observed at a third location containing F1 hybrids, indicating that interspecific mating behavior varied among locations. Backcrossed individuals were found in drainages lacking F1 hybrids and in populations previously thought to contain a single species. The extent and distribution of backcrossed individuals suggested that at least some hybrids are reproductively viable and backcrossed hybrid offspring move throughout the system.

  13. Genetic variation in steelhead of Oregon and northern California

    USGS Publications Warehouse

    Reisenbichler, R.R.; McIntyre, J.D.; Solazzi, M.F.; Landino, S.W

    1992-01-01

    Steelhead Oncorhynchus mykiss from various sites between the Columbia River and the Mad River, California, were genetically characterized at 10 protein-coding loci or pairs of loci by starch gel electrophoresis. Fish from coastal streams differed from fish east of the Cascade Mountains and from fish of the Willamette River (a tributary of the Columbia River, west of the Cascade Mountains). Coastal steelhead from the northern part of the study area differed from those in the southern part. Genetic differentiation within and among drainages was not statistically significant; however, gene diversity analysis and the life history of steelhead suggested that fish from different drainages should be considered as separate populations. Genetic variation among fish in separate drainages was similar to that reported in northwestern Washington and less than that reported in British Columbia. Allele frequencies varied significantly among year-classes. Genetic variation within samples accounted for 98.3% of the total genetic variation observed in this study. Most hatchery populations differed from wild populations, suggesting that conservation of genetic diversity among and within wild populations could be facilitated by altering hatchery programs.

  14. Physiological indices of seawater readiness in postspawning steelhead kelts

    USGS Publications Warehouse

    Buelow, Jessica; Moffitt, Christine M.

    2015-01-01

    Management goals to improve the recovery of steelhead (Oncorhynchus mykiss) stocks at risk of extinction include increasing the proportion of postspawning fish that survive and spawn again. To be successful, postspawning steelhead (kelts) migrating downstream to the ocean must prepare physiologically and physically for a seawater transition. We sampled blood, gill filaments, and evaluated the external condition of migrating kelts from an ESA-listed population in the Snake/Columbia River system over two consecutive years to evaluate their physiological readiness for transition to seawater. We chose attributes often considered as measures of preparation for seawater in juveniles, including gill Na+,K+ ATPase activity, plasma electrolytes and hormones to consider factors related to external condition, size and sex. We found kelts in good external condition had plasma profiles similar to downstream-migrating smolts. In addition, we found more than 80% of kelts ranked in good external condition had smolt-like body silvering. We compared measures from migrating kelts with samples obtained from hatchery fish at the time of spawning to confirm that Na+, K+ ATPase activity in kelts was significantly elevated over spawning fish. We found significant differences in gill Na+, K+ ATPase activity in migrating kelts between the years of sampling, but little indication of influence of fish condition. We conclude that the postspawning steelhead sampled exhibited a suite of behaviours, condition and physiology characteristic of fish prepared for successful transition to a seawater environment.

  15. Chapter 5. Yellowstone cutthroat trout

    Treesearch

    Robert E. Gresswell

    1995-01-01

    The Yellowstone cutthroat trout is more abundant and inhabits a greater geographical range than does any other nonanadronnous subspecies of cutthroat trout (Varley and Gresswell 1988). The Yellowstone cutthroat trout was indigenous to the Snake River upstream from Shoshone Falls, Idaho, and the Yellowstone River above the Tongue River, Montana (Behnke 1992). Although...

  16. Bioenergetic response by steelhead to variation in diet, thermal habitat, and climate in the north Pacific Ocean

    USGS Publications Warehouse

    Atcheson, Margaret E.; Myers, Katherine W.; Beauchamp, David A.; Mantua, Nathan J.

    2012-01-01

    Energetic responses of steelhead Oncorhynchus mykiss to climate-driven changes in marine conditions are expected to affect the species’ ocean distribution, feeding, growth, and survival. With a unique 18-year data series (1991–2008) for steelhead sampled in the open ocean, we simulated interannual variation in prey consumption and growth efficiency of steelhead using a bioenergetics model to evaluate the temperature-dependent growth response of steelhead to past climate events and to estimate growth potential of steelhead under future climate scenarios. Our results showed that annual ocean growth of steelhead is highly variable depending on prey quality, consumption rates, total consumption, and thermal experience. At optimal growing temperatures, steelhead can compensate for a low-energy diet by increasing consumption rates and consuming more prey, if available. Our findings suggest that steelhead have a narrow temperature window in which to achieve optimal growth, which is strongly influenced by climate-driven changes in ocean temperature.

  17. Wild Steelhead and introduced spring Chinook Salmon in the Wind River, Washington: Overlapping populations and interactions

    USGS Publications Warehouse

    Jezorek, I.G.; Connolly, P.J.

    2010-01-01

    We investigated interactions of introduced juvenile spring Chinook salmon Oncorhynchus tshawytscha with wild juvenile steelhead O. mykiss in the upper Wind River watershed (rkm 24.6 to rkm 43.8), Washington. Our objective was to determine if the presence of introduced spring Chinook salmon influenced populations of wild juvenile steelhead and if other biotic or abiotic factors influenced distribution and populations of these species. We snorkeled to assess distribution and abundance in one to six stream reaches per year during 2001 through 2007. Juvenile steelhead were found in each sampled reach each year, but juvenile Chinook salmon were not. The upstream extent of distribution of juvenile Chinook salmon varied from rkm 29.7 to 42.5. Our analyses suggest that juvenile Chinook salmon distribution was much influenced by flow during the spawning season. Low flow appeared to limit access of escaped adult Chinook salmon to upper stream reaches. Abundance of juvenile Chinook salmon was also influenced by base flow during the previous year, with base flow occurring post spawn in late August or early September. There were no relationships between juvenile Chinook salmon abundance and number of Chinook salmon spawners, magnitude of winter flow that might scour redds, or abundance of juvenile steelhead. Abundance of age-0 steelhead was influenced primarily by the number of steelhead spawners the previous year, and abundance of age-1 steelhead was influenced primarily by abundance of age-0 steelhead the previous year. Juvenile steelhead abundance did not show a relationship with base or peak flows, nor with number of escaped Chinook salmon adults during the previous year. We did not detect a negative influence of the relatively low abundance of progeny of escaped Chinook salmon on juvenile steelhead abundance. This low abundance of juvenile Chinook salmon was persistent throughout our study and is likely a result of hatchery management and habitat conditions. Should one or

  18. Biological characteristics and population status of steelhead (Oncorhynchus mykiss) in southeast Alaska.

    Treesearch

    Samuel C. Lohr; Mason D. Bryant

    1999-01-01

    We reviewed existing data to determine the range and distribution of steelhead (Oncorhynchus mykiss) in southeast Alaska, summarized biological characteristics, and determined population status of steelhead stocks. Unique or sensitive stocks that may require consideration in planning land management activities are identified within the data...

  19. Monitoring and Evaluation of Smolt Migration in the Columbia Basin, Volume XIV; Evaluation of 2006 Prediction of the Run-Timing of Wild and Hatchery-Reared Salmon and Steelhead at Rock Island, Lower Granite, McNary, John Day and Bonneville Dams using Program Real Time, Technical Report 2006.

    SciTech Connect

    Griswold, Jim

    2007-01-01

    Program RealTime provided monitoring and forecasting of the 2006 inseason outmigrations via the internet for 32 PIT-tagged stocks of wild ESU chinook salmon and steelhead to Lower Granite and/or McNary dams, one PIT-tagged hatchery-reared ESU of sockeye salmon to Lower Granite Dam, and 20 passage-indexed runs-at-large, five each to Rock Island, McNary, John Day, and Bonneville Dams. Twenty-four stocks are of wild yearling chinook salmon which were captured, PIT-tagged, and released at sites above Lower Granite Dam in 2006, and have at least one year's historical migration data previous to the 2006 migration. These stocks originate in drainages of themore » Salmon, Grande Ronde and Clearwater Rivers, all tributaries to the Snake River, and are subsequently detected through the tag identification and monitored at Lower Granite Dam. In addition, seven wild PIT-tagged runs-at-large of Snake or Upper Columbia River ESU salmon and steelhead were monitored at McNary Dam. Three wild PIT-tagged runs-at-large were monitored at Lower Granite Dam, consisting of the yearling and subyearling chinook salmon and the steelhead trout runs. The hatchery-reared PIT-tagged sockeye salmon stock from Redfish Lake was monitored outmigrating through Lower Granite Dam. Passage-indexed stocks (stocks monitored by FPC passage indices) included combined wild and hatchery runs-at-large of subyearling and yearling chinook, coho, and sockeye salmon, and steelhead trout forecasted to Rock Island, McNary, John Day, and Bonneville Dams.« less

  20. Trout Creek 1999 Burn

    Treesearch

    Sherel Goodrich

    2008-01-01

    A small prescribed fire near the mouth of Trout Creek in Strawberry Valley, Wasatch County, Utah, on the Uinta National Forest provided an opportunity to compare production and vascular plant composition in unburned and burned areas. At four years post burn, production of herbaceous plants was about four times greater in the burned area than in the unburned area. Most...

  1. Analysis of Salmon and Steelhead Supplementation, 1990 Final Report.

    SciTech Connect

    Miller, William H.; Coley, Travis C.; Burge, Howard L.

    1990-09-01

    Supplementation or planting salmon and steelhead into various locations in the Columbia River drainage has occurred for over 100 years. All life stages, from eggs to adults, have been used by fishery managers in attempts to establish, rebuild, or maintain anadromous runs. This report summarizes and evaluates results of past and current supplementation of salmon and steelhead. Conclusions and recommendations are made concerning supplementation. Hatchery rearing conditions and stocking methods can affect post released survival of hatchery fish. Stress was considered by many biologists to be a key factor in survival of stocked anadromous fish. Smolts were the most commonmore » life stage released and size of smolts correlated positively with survival. Success of hatchery stockings of eggs and presmolts was found to be better if they are put into productive, underseeded habitats. Stocking time, method, species stocked, and environmental conditions of the receiving waters, including other fish species present, are factors to consider in supplementation programs. The unpublished supplementation literature was reviewed primarily by the authors of this report. Direct contact was made in person or by telephone and data compiled on a computer database. Areas covered included Oregon, Washington, Idaho, Alaska, California, British Columbia, and the New England states working with Atlantic salmon. Over 300 projects were reviewed and entered into a computer database. The database information is contained in Appendix A of this report. 6 refs., 9 figs., 21 tabs.« less

  2. Examining indirect effects of lake trout recovery

    EPA Science Inventory

    With the recovery of lake trout populations in Lake Superior, there are indications of decreased forage fish abundance and density-dependence in lake trout. In Lake Superior, lean lake trout historically occupied depths < 60 m, and siscowet lake trout occupied depths > 60 m...

  3. Embryotoxicity of an extract from Great Lakes lake trout to rainbow trout and lake trout

    SciTech Connect

    Wright, P.J.; Tillitt, D.E.

    1995-12-31

    Aquatic ecosystems such as the Great Lakes are known to be contaminated with chemicals that are toxic to fish. However, the role of these contaminants in reproductive failures of fishes, such as lake trout recruitment, has remained controvertible. It was the objective to evaluate dioxin-like embryotoxicity of a complex mixture of chemicals and predict their potential to cause the lack of recruitment in Great Lakes lake trout. Graded doses of a complex environmental extract were injected into eggs of both rainbow trout and lake trout. The extract was obtained from whole adult lake trout collected from Lake Michigan in 1988.more » The extract was embryotoxic in rainbow trout, with LD50 values for Arlee strain and Erwin strain of 33 eggEQ and 14 eggEQ respectively. The LOAEL for hemorrhaging, yolk-sac edema, and craniofacial deformities in rainbow trout were 2, 2, and 4 eggEQ, respectively. Subsequent injections of the extract into lake trout eggs were likewise embryotoxic, with an LD50 value of 7 eggEQ. The LOAEL values for the extract in lake trout for hemorrhaging, yolk-sac edema, and craniofacial deformities were 0.1, 1, and 2 eggEQ, respectively. The current levels of contaminants in lake trout eggs are above the threshold for hemorrhaging and yolk-sac edema. The results also support the use of an additive model of toxicity to quantify PCDDs, PCDFs, Non-o-PCBs, and Mono-o-PCBs in relation to early life stage mortality in Lake Michigan lake trout.« less

  4. Trout in the Classroom

    NASA Astrophysics Data System (ADS)

    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

  5. Relationship of external fish condition to pathogen prevalence and out-migration survival in juvenile steelhead

    USGS Publications Warehouse

    Hostetter, N.J.; Evans, A.F.; Roby, D.D.; Collis, K.; Hawbecker, M.; Sandford, B.P.; Thompson, D.E.; Loge, F.J.

    2011-01-01

    Understanding how the external condition of juvenile salmonids is associated with internal measures of health and subsequent out-migration survival can be valuable for population monitoring programs. This study investigated the use of a rapid, nonlethal, external examination to assess the condition of run-of-the-river juvenile steelhead Oncorhynchus mykiss migrating from the Snake River to the Pacific Ocean. We compared the external condition (e.g., body injuries, descaling, external signs of disease, fin damage, and ectoparasite infestations) with (1) the internal condition of a steelhead as measured by the presence of selected pathogens detected by histopathology and polymerase chain reaction analysis and (2) out-migration survival through the Snake and Columbia rivers as determined by passive integrated transponder (PIT) tag technology. The results from steelhead captured and euthanized (n = 222) at Lower Monumental Dam on the lower Snake River in 2008 indicated that external condition was significantly correlated with selected measures of internal condition. The odds of testing positive for a pathogen were 39.2, 24.3, and 5.6 times greater for steelhead with severe or moderate external signs of disease or more than 20% descaling, respectively. Capture-recapture models of 22,451 PIT-tagged steelhead released at Lower Monumental Dam in 2007-2009 indicated that external condition was significantly correlated with juvenile survival. The odds of outmigration survival for steelhead with moderate or severe external signs of disease, more than 20% descaling, or severe fin damage were 5.7, 4.9, 1.6, and 1.3 times lower, respectively, than those for steelhead without these external conditions. This study effectively demonstrated that specific measures of external condition were associated with both the internal condition and out-migration survival of juvenile steelhead. ?? American Fisheries Society 2011.

  6. Sluiceway Operations for Adult Steelhead Downstream Passage at The Dalles Dam, Columbia River, USA

    SciTech Connect

    Khan, Fenton; Royer, Ida M.; Johnson, Gary E.

    2013-10-01

    This study evaluated adult steelhead (Oncorhynchus mykiss; fallbacks and kelts) downstream passage at The Dalles Dam in the Columbia River, USA, during the late fall, winter, and early spring months between 2008 and 2011. The purpose of the study was to determine the efficacy of operating the dam’s ice-and-trash sluiceway during non-spill months to provide a relatively safe, non-turbine, surface outlet for overwintering steelhead fallbacks and downstream migrating steelhead kelts. We applied the fixed-location hydroacoustic technique to estimate fish passage rates at the sluiceway and turbines of the dam. The spillway was closed during our sampling periods, which generally occurredmore » in late fall, winter, and early spring. The sluiceway was highly used by adult steelhead (91–99% of total fish sampled passing the dam) during all sampling periods. Turbine passage was low when the sluiceway was not operated. This implies that lack of a sluiceway route did not result in increased turbine passage. However, when the sluiceway was open, adult steelhead used it to pass through the dam. The sluiceway may be operated during late fall, winter, and early spring to provide an optimal, non-turbine route for adult steelhead (fallbacks and kelts) downstream passage at The Dalles Dam.« less

  7. Influence of a Weak Field of Pulsed DC Electricity on the Behavior and Incidence of Injury in Adult Steelhead and Pacific Lamprey, Final Report.

    SciTech Connect

    Mesa, Matthew

    2009-02-13

    . Field electrofishing operations typically use high voltage and amperage settings and a variety of waveforms, pulse widths (PW), and pulse frequencies (PF), depending on conditions and target species. For example, when backpack electrofishing for trout in a small stream, one might use settings such as 500 V pulsed DC, a PW of 1 ms, and a PF of 60 Hz. In contrast, the electrical barrier proposed by SRI will produce electrical conditions significantly lower than those used in electrofishing, particularly for PW and PF (e.g., PW ranging from 300-1,000 {micro}s and PF from 2-3 Hz). Further, voltage gradients (in V/cm) are predicted to be lower in the electric barrier than those produced during typical electrofishing. Although the relatively weak, pulsed DC electric fields to be produced by the barrier may be effective at deterring pinnipeds, little, if anything, is known about the effects of such low intensity electrical fields on fish behavior. For this research, we evaluated the effects of weak, pulsed DC electric currents on the behavior of adult steelhead and Pacific lamprey and the incidence of injury in steelhead only. In a series of laboratory experiments, we: (1) documented the rate of passage of fish over miniature, prototype electric barriers when they were on and off; (2) determined some electric thresholds beyond which fish would not pass over the barrier; and (3) assessed the incidence and severity of injury in steelhead exposed to relatively severe electrical conditions. The results of this study should be useful for making decisions about whether to install electrical barriers in the lower Columbia River, or elsewhere, to reduce predation on upstream migrating salmonids and other fishes by marine pinnipeds.« less

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

    USGS Publications Warehouse

    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

  9. Coupled stream and population dynamics: Modeling the role beaver (Castor canadensis) play in generating juvenile steelhead (Oncorhynchus mykiss) habitat

    NASA Astrophysics Data System (ADS)

    Jordan, C.; Bouwes, N.; Wheaton, J. M.; Pollock, M.

    2013-12-01

    Over the past several centuries, the population of North American Beaver has been dramatically reduced through fur trapping. As a result, the geomorphic impacts long-term beaver occupancy and activity can have on fluvial systems have been lost, both from the landscape and from our collective memory such that physical and biological models of floodplain system function neither consider nor have the capacity to incorporate the role beaver can play in structuring the dynamics of streams. Concomitant with the decline in beaver populations was an increasing pressure on streams and floodplains through human activity, placing numerous species of stream rearing fishes in peril, most notably the ESA listing of trout and salmon populations across the entirety of the Western US. The rehabilitation of stream systems is seen as one of the primary means by which population and ecosystem recovery can be achieved, yet the methods of stream rehabilitation are applied almost exclusively with the expected outcome of a static idealized stream planform, occasionally with an acknowledgement of restoring processes rather than form and only rarely with the goal of a beaver dominated riverscape. We have constructed an individual based model of trout and beaver populations that allows the exploration of fish population dynamics as a function of stream habitat quality and quantity. We based the simulation tool on Bridge Creek (John Day River basin, Oregon) where we have implemented a large-scale restoration experiment using wooden posts to provide beavers with stable platforms for dam building and to simulate the dams themselves. Extensive monitoring captured geomorphic and riparian changes, as well as fish and beaver population responses; information we use to parameterize the model as to the geomorphic and fish response to dam building beavers. In the simulation environment, stream habitat quality and quantity can be manipulated directly through rehabilitation actions and indirectly

  10. PEPA-1* genotype affects return rate for hatchery steelhead

    USGS Publications Warehouse

    Reisenbichler, R.R.; Hayes, M.C.; Rubin, S.P.; Wetzel, L.A.; Baker, B.M.

    2006-01-01

    Allozymes continue to be useful as genetic markers in a variety of studies; however, their utility often hinges on the selective neutrality of the allelic variation. Our study tested for neutrality between the two most common alleles (*100 and *110) at the cytosol nonspecific dipeptidase locus (PEPA-1*) in steelhead Oncorhynchus mykiss from Dworshak National Fish Hatchery in Idaho. We tested for differential growth and survival among fish with the * 100/100, *100/ 110, and *110/110 genotypes rearing in a hatchery or a natural stream. We repeated the study for two year-classes, using heterozygous (*100/110) adults to make the experimental crosses. This design avoided differences in family contribution among genotypes because each cross produced all three genotypes. We divided the progeny from each family into two groups. One group was reared in a hatchery for 1 year and then released for migration to the sea and subsequent return to the hatchery as adults. The other group was released into a natural stream and monitored for 3 years. We found no significant differences in size or survival among PEPA-1* genotypes for either the naturally reared fish or the hatchery-reared fish immediately prior to release as smolts. For females, survival to returning adult also was similar among genotypes; however, hatchery-reared males with the *110/110 genotype returned at a higher rate than did males with the *100/ 100 genotype; heterozygous males were intermediate. These results indicate that selection occurs at the PEPA-1* locus or at one or more loci tightly linked to it. The finding of nearly equal frequencies for these two alleles in the source population suggests that selection differentials among genotypes reverse or vary from year to year; otherwise, steady directional selection would drive the *100 allele to low frequencies or extinction. Locus PEPA-1* seems inappropriate for genetic marks in studies of steelhead that span the full life cycle and probably should be avoided

  11. Assessing fish predation on migrating juvenile steelhead and a retrospective comparison to steelhead survival through the Priest Rapids Hydroelectric Project, Columbia River, Washington, 2009-11

    USGS Publications Warehouse

    Hardiman, Jill M.; Counihan, Timothy D.; Burgess, Dave S.; Simmons, Katrina E.; Holmberg, Glen S.; Rogala, Josh; Polacek, Rochelle

    2012-01-01

    The U.S. Geological Survey (USGS) and the Washington Department of Fish and Wildlife (WDFW) have been working with the Public Utility District No. 2 of Grant County, Washington (Grant PUD), to increase their understanding of predator-prey interactions in the Priest Rapids Hydroelectric Project (PRP), Columbia River, Washington. For this study, the PRP is defined as the area approximately 6 kilometers upstream of Wanapum Dam to the Priest Rapids Dam tailrace, 397.1 miles from the mouth of the Columbia River. Past year’s low survival numbers of juvenile steelhead (Oncorhynchus mykiss) through Wanapum and Priest Rapids Dams has prompted Grant PUD, on behalf of the Priest Rapids Coordinating Committee, to focus research efforts on steelhead migration and potential causal mechanisms for low survival. Steelhead passage survival in 2009 was estimated at 0.944 through the Wanapum Development (dam and reservoir) and 0.881 through the Priest Rapids Development and for 2010, steelhead survival was 0.855 for Wanapum Development and 0.904 for Priest Rapids Development. The USGS and WDFW implemented field collection efforts in 2011 for northern pikeminnow (Ptychocheilus oregonensis), smallmouth bass (Micropterus dolomieu), and walleye (Sander vitreus, formerly Stizostedion vitreum) and their diets in the PRP. For predator indexing, we collected 948 northern pikeminnow, 237 smallmouth bass, 18 walleye, and two largemouth bass (Micropterus salmoides). The intent of this study was to provide standardized predation indices within individual reaches of the PRP to discern spatial variability in predation patterns. Furthermore, the results of the 2011 study were compared to results of a concurrent steelhead survival study. Our results do not indicate excessively high predation of Oncorhynchus spp. occurring by northern pikeminnow or smallmouth bass in any particular reach throughout the study area. Although we found Oncorhynchus spp. in the predator diets, the relative

  12. Competition and predation as mechanisms for displacement of greenback cutthroat trout by brook trout

    Treesearch

    C. C. McGrath; W. M. Lewis

    2007-01-01

    Cutthroat trout Oncorhynchus clarkii frequently are displaced by nonnative brook trout Salvelinus fontinalis, but the ecological mechanisms of displacement are not understood. Competition for food and predation between greenback cutthroat trout O. c. stomias and brook trout were investigated in montane streams of...

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

    USGS Publications Warehouse

    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.

  14. Influence of costocking on growth of young-of-year brook trout and rainbow trout

    USGS Publications Warehouse

    Isely, J.J.; Kempton, C.

    2000-01-01

    We examined the effects of costocking on growth of hatchery-produced young-of-year brook trout Salvelinus fontinalis and rainbow trout Oncorhynchus mykiss in the laboratory. Fry of both species (brook trout = 0.16 ?? 0.01 g; rainbow trout = 0.18 ?? 0.01 g; mean weight ?? standard deviation) were stocked into 400-L recirculation raceways at a rate of 100 fish/raceway and were held at 12??C. Raceways received either rainbow trout only (n = 3), brook trout only (n = 3), or half brook trout and half rainbow trout (n = 3). Trout were fed a commercial trout feed three times per day at an initial rate of 10% body weight/d, which was reduced to 3% body weight/d by the 6th week of the study as a result of a buildup of excess feed. After 8 weeks of similar treatment, brook trout were significantly larger than rainbow trout (in terms of length and weight) when they were stocked alone. However, rainbow trout were significantly larger than brook trout (in terms of length and weight) in the costocked treatment. A second phase of the study was conducted to evaluate the effect of ration level on growth of costocked brook and rainbow trout using low (2% body weight/d), medium (4% body weight/d), and high (6% body weight/d) ration levels. After 8 weeks, rainbow trout were significantly larger than brook trout (in terms of length and weight) in all costocked feeding treatments. This suggests that behavioral interaction might have resulted in decreased growth of brook trout when they were costocked with rainbow trout.

  15. Individual condition, standard metabolic rate, and rearing temperature influence steelhead and rainbow trout (Oncorhynchus mykiss) life histories

    Treesearch

    Matthew R. Sloat; Gordon H. Reeves

    2014-01-01

    We reared juvenile Oncorhychus mykiss with low and high standard metabolic rates (SMR) under alternative thermal regimes to determine how these proximate factors influence life histories in a partially migratory salmonid fish. High SMR significantly decreased rates of freshwater maturation and increased rates of smoltification in females, but not...

  16. Mycobacterial infections in adult salmon and steelhead trout returning to the Columbia River Basin and other areas in 1957

    USGS Publications Warehouse

    1959-01-01

    The degree of incidence of acid -fast bacillus infections in adult salmonid fishes was determined. The disease was shown to be widely distributed in the area examined. It is believed the primary source of infection is derived from the hatchery practice of feeding infected salmon products to juvenile fish. One group of marked adults that had been hatchery reared for 370 days showed a 62 percent incidence of infection. A statistical analysis indicated that length of fish is independent of infection

  17. The effects of river impoundment and hatchery rearing on the migration behavior of juvenile steelhead in the Lower Snake River, Washington

    USGS Publications Warehouse

    Plumb, J.M.; Perry, R.W.; Adams, N.S.; Rondorf, D.W.

    2006-01-01

    We used radiotelemetry to monitor the migration behavior of juvenile hatchery and wild steelhead Oncorhynchus mykiss as they migrated through Lower Granite Reservoir and Dam on the lower Snake River, Washington. From 1996 to 2001, we surgically implanted radio transmitters in 1,540 hatchery steelhead and 1,346 wild steelhead. For analysis, we used the inverse Gaussian distribution to describe travel time distributions for cohorts (>50 fish) of juvenile steelhead as they migrated downriver. Mean travel rates were significantly related to reach- and discharge-specific water velocities. Also, mean travel rates near the dam were slower for a given range of water velocities than were mean travel rates through the reservoir, indicating that the presence of the dam caused delay to juvenile steelhead over and above the effect of water velocity. Hatchery steelhead took about twice as long as wild steelhead to pass the dam as a result of the higher proportions of hatchery steelhead traveling upriver from the dam. Because upriver travel and the resulting migration delay might decrease survival, it is possible that hatchery steelhead survive at lower rates than wild steelhead. Our analysis identified a discharge threshold (???2,400 m3/s) below which travel time and the percentage of fish traveling upriver from the dam increased rapidly, providing support for the use of minimum flow targets to mitigate for fish delay and possibly enhance juvenile steelhead survival.

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

    USGS Publications Warehouse

    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.

  19. Furunculosis in wild trout

    USGS Publications Warehouse

    Fish, F.F.

    1937-01-01

    Furunculosis, or as it has been more appropiately termed, "fish septicemia," is a disease primarily affecting salmon and trout. It is caused by the invasion and growth of Bacterium salmonicida Emmerich and Weibel, a Gram negative, non-spore forming, diplobacterium belonging to the family Bacteriaceae Cohn. After gaining entrance to the host, presumably by way of the digestive tract, the organism is spread by the blood stream and produces focal necrosis and subsequent liquefaction throughout the tissues. The more conspicuous gross lesions are those of the body musculature, characterized by the formation of deep seated "boils" or "bloody blotches"—blisters filled with liquefied muscle tissue and blood. Under favorable conditions, the muscle lesions enlarge rapidly and eventually rupture through the skin producing a characteristic, ragged, deep, undermining type of ulcer. Although the muscle lesions are most conspicuous, essentially the same progressive necrosis and liquefaction are to be found throughout the internal organs, particularly in the spleen and kidneys. The host has no adequate defense mechanism against this disease and no verified recovery from furunculosis has ever been recorded. Cases may be arrested by low water temperatures or other adverse factors, only to break out with renewed vigor when conditions again become favorable. The reader is referred to Plehn, Davis, Williamson, and Duff and Stewart for a more complete description of furunculosis.

  20. ASSESSING THE IMPORTANCE OF THERMAL REFUGE USE TO MIGRATING ADULT SALMON AND STEELHEAD

    EPA Science Inventory

    Salmon populations require river networks that provide water temperature regimes sufficient to support a diversity of salmonid life histories across space and time. The importance of cold water refuges for migrating adult salmon and steelhead may seem intuitive, and refuges are c...

  1. 77 FR 1669 - Endangered and Threatened Species; Recovery Plan for the Southern California Steelhead Distinct...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-11

    ... and Threatened Species; Recovery Plan for the Southern California Steelhead Distinct Population... (Oncorhynchus mykiss) Distinct Population Segment (DPS), which spawn and rear in coastal rivers from the Santa... testing confirmed that these O. mykiss were most closely related to the more northern populations of the...

  2. Development of a Willingness to Pay Survey for Willamette Basin Spring Chinook and Winter Steelhead Recovery

    EPA Science Inventory

    Salmon fisheries are a high-profile icon of the Pacific Northwest. Spring Chinook and winter-run steelhead are both listed as federally endangered species in the Willamette basin, the most populated and developed watershed in Oregon. Despite being a high profile issue, there are ...

  3. Characteristics of pools used by adult summer steelhead oversummering in the New River, California

    Treesearch

    Rodney J. Nakamoto

    1994-01-01

    Abstract - I assessed characteristics of pools used by oversummering adults of summer steelhead Oncorhynchus mykiss between July and October 1991 in the New River, northwestern California. Most fish occupied channel confluence pools and other pools of moderate size (200-1,200 m 2); these pools had less than 35% substrate embeddedness and mean water depths of about 1.0...

  4. Winter food habits of coastal juvenile steelhead and coho salmon in Pudding Creek, northern California

    Treesearch

    Heather Anne Pert

    1993-01-01

    The objectives of this study were to determine winter food sources, availability, and preferences for coho salmon (Oncorhynchus kisutch) and steelhead (Oncorhynchus mykiss) in Pudding Creek, California. The majority of research on overwintering strategies of salmonids on the West Coast has been done in cooler, northern climates studying primarily the role of habitat...

  5. Predicting the potential for historical coho, chinook and steelhead habitat in northern California.

    Treesearch

    A. Agrawal; R.S. Schick; E.P. Bjorkstedt; R.G. Szerlong; M.N. Goslin; B.C. Spence; T.H. Williams; K.M. Burnett

    2005-01-01

    Numerous Evolutionarily Significant Units (ESUs) of salmon and steelhead in California and the Pacific Northwest have been listed under the U.S. Endangered Species Act (ESA). In response, NOAA Fisheries convened Technical Recovery Teams (TRTs) to develop biological viability criteria for the listed ESUs. An understanding of biological structure is a critical first step...

  6. The effects of water depth on prey detection and capture by juvenile coho salmon and steelhead

    Treesearch

    J.J. Piccolo; N.F. Hughes; M.D. Bryant

    2007-01-01

    We used three-dimensional video analysis of feeding experiments to determine the effects of water depth on prey detection and capture by drift-feeding juvenile coho salmon (Oncorhynchus kisutch) and steelhead (0. mykiss irideus). Depth treatments were 0.15, 0.30, 0.45 and 0.60 m. Mean prey capture probabilities for both species...

  7. Development of a Progeny Marker for Steelhead; A Thesis submitted to Oregon State University.

    SciTech Connect

    Shippentower, Gene E.

    2009-04-15

    This study was undertaken to determine if strontium chloride could be used to create a trans-generational otolith mark in steelhead (Oncorhynchus mykiss). I completed two strontium injection trials and a survey of juvenile steelhead from various steelhead hatcheries. The two trials measured Sr:Ca ratios in otoliths in response to injections and the survey measured the natural variation in Sr:Ca ratios in otoliths of juvenile hatchery steelhead in response to the natural variation. In 2003, adult female Wallowa River, Oregon O. mykiss, were captured at the hatchery and evenly divided between a control group and two treatment groups. These females receivedmore » an intraperitoneal injection of 1cc/500 g of body weight of a physiologically isotonic solution (0.9% saline) containing concentrations of 0 (control), 1000, or 5000 parts per million (ppm) of strontium chloride hexahydrate (SrCl 2* 6H 2O). Females were housed in a single outdoor tank until spawned artificially, and a distinct external tag identified each female within each treatment group. In 2004, female steelhead were captured throughout the duration of the adult returns to the Umatilla River basin and injected with 0, 1000, 5000, or 20,000-ppm strontium. In both trials, progeny of fish treated with strontium had significantly higher Sr:Ca ratios in the primordial region of their otoliths as measured using an electron wavelength dispersive microprobe. There was no difference in fertilization rates of eggs and survival rates of fry among treatment groups. Progeny from treated mothers were on average larger than progeny of untreated mothers. The Sr:Ca ratios in otoliths collected from various populations of steelhead were greater than the control values measured in both injections studies. This study suggests that the marking technique works and the utility for such a technique could be used for empirical observations in determining the relative fitness of progeny of adult hatchery origin fish that spawn

  8. Winter Habitats of Atlantic Salmon, Brook Trout, Brown Trout and Rainbow Trout: A Literature Review

    DTIC Science & Technology

    1989-10-01

    streambedpacked with fine substrate river ice processes can be found in Ashton (1986). materials showed no indications of subcooling The ice can have some...gravels Brook trout Eggs/embryos* 0.3-5 Reiser & Wesche (1979) Fry 27-40 0.5-4.3 10-40 Cunjak & Power (1986) Juveniles/adults 40-95 4.6-17.8 - Cunjak...Power (1986) Adults - ᝿ sand/silt Chisholm et a!. (1987) Brown trout Eggs/embryos* >9 15-46 gravel Reiser & Wesche (1977) Fry 43-46 2.2-4.7 boulders

  9. Bigger is not always better for overwintering young-of-year steelhead

    USGS Publications Warehouse

    Connolly, P.J.; Petersen, J.H.

    2003-01-01

    Many fishes occur across broad ranges of latitude and elevation, where winter temperatures can vary from mild to harsh. We conducted a laboratory experiment with three sizes of age-0 steelhead Oncorhynchus mykiss to examine growth, condition, and energy reserves under low rations at three levels of water temperature typical of this species' distribution during winter. At the end of the 111-d experiment, all three starting sizes of age-0 steelhead (small, 2-3 g; medium, 3-4 g; large, 4-5 g) held in 3??C water had lower total lipid weight than those held in 6??C and 9??C water. Large fish had higher total lipid weight than small fish at the onset of the experiment and retained higher amounts at the end. However, large fish had either the lowest percentage increases or the highest percentage decreases in fork length, biomass, condition factor, total lipid weight, and percent lipids within all thermal treatments. The magnitude of the differences between small and large fish was highest in the warmest (9??C) water. We used bioenergetics simulations of juvenile steelhead growth to examine fish response to initial size, winter temperature, and food availability. Relatively warm water temperatures in winter, coupled with limited food availability, may present more of a physiological challenge to larger age-0 steelhead than to smaller fish. Our results suggest that achievement of large size before the start of a steelhead's first winter can have a cost under episodic conditions found across the wide ranges of latitude and elevation within this species' distribution.

  10. Effectiveness and retention of thiamine and its analogs administered to steelhead and landlocked Atlantic salmon

    USGS Publications Warehouse

    Ketola, H.G.; Isaacs, G.R.; Robins, J.S.; Lloyd, R.C.

    2008-01-01

    We investigated the feasibility of enhancing the reproduction of steelhead Oncorhynchus mykiss and landlocked Atlantic salmon Salmo salar in lakes where the consumption of alewives Alosa pseudoharengus and other forage fishes containing thiaminase can cause them to become thiamine deficient and thereby reduce the survival of their fry. We evaluated feeding fingerling steelhead excess thiamine hydrochloride (THCl) for 1 or 2 weeks or equimolar amounts of thiamine mononitrate, thiamine-tetrahydrofurfuryl-disulfide, benfotiamine, or dibenzoyl thiamine (DBT). We found minimal internal reserves of thiamine after 6 months. We also compared the ability of injections of thiamine and its analogs to prevent mortality in thiamine-deficient steelhead and Atlantic salmon sac fry and found all forms to be effective, although benfotiamine was the least effective on an equimolar basis. Further, we injected yearling steelhead and found that DBT was tolerated at approximately 11,200 nmol/g of body weight, about 10 times more than thiamine in any other form. When yearling steelhead were injected with near-maximal doses of thiamine hydrochloride and several analogs and then fed a thiamine-deficient diet, DBT was retained for approximately 2 years - in contrast to other forms, which were retained for less than about 6 months. Therefore, these results suggest that neither feeding nor injecting young hatchery salmonids with DBT is likely to enhance their reproduction for more than 2 years after stocking. However, injecting DBT in nearly mature fish (either cultured fish from hatcheries or wild fish captured in lakes) may provide them with enough thiamine to successfully spawn within 2 years even though they consume mainly thiaminase-containing forage fishes. ?? Copyright by the American Fisheries Society 2008.

  11. Chapter 4. Bonneville cutthroat trout

    Treesearch

    Jeffrey L. Kershner

    1995-01-01

    In this little stream, the trout are more abundant than we have yet seen them. One of our sober men took, this afternoon, upward of thirty pounds. These fish would probably average fifteen or sixteen inches in length, and weigh three-quarters of a pound; occasionally, however, a much larger one is seen." This passage from the journal of John Townsend, a trader...

  12. Chapter 1. Westslope cutthroat trout

    Treesearch

    John D. McIntyre; Bruce E. Rieman

    1995-01-01

    The westslope cutthroat trout inhabits streams on both sides of the Continental Divide. On the east side of the divide, they are distributed mostly in Montana but also occur in some headwaters in Wyoming and southern Alberta (Behnke 1992). They are in the Missouri Basin downstream to about 60 km below Great Falls and in the headwaters of the Judith, Milk, and Marias...

  13. Growth, morphology, and developmental instability of rainbow trout, Yellowstone cutthroat trout, and four hybrid generations

    USGS Publications Warehouse

    Ostberg, C.O.; Duda, J.J.; Graham, J.H.; Zhang, S.; Haywood, K. P.; Miller, B.; Lerud, T.L.

    2011-01-01

    Hybridization of cutthroat trout Oncorhynchus clarkii with nonindigenous rainbow trout O. mykiss contributes to the decline of cutthroat trout subspecies throughout their native range. Introgression by rainbow trout can swamp the gene pools of cutthroat trout populations, especially if there is little selection against hybrids. We used rainbow trout, Yellowstone cutthroat trout O. clarkii bouvieri, and rainbow trout × Yellowstone cutthroat trout F1 hybrids as parents to construct seven different line crosses: F1 hybrids (both reciprocal crosses), F2 hybrids, first-generation backcrosses (both rainbow trout and Yellowstone cutthroat trout), and both parental taxa. We compared growth, morphology, and developmental instability among these seven crosses reared at two different temperatures. Growth was related to the proportion of rainbow trout genome present within the crosses. Meristic traits were influenced by maternal, additive, dominant, overdominant, and (probably) epistatic genetic effects. Developmental stability, however, was not disturbed in F1 hybrids, F2 hybrids, or backcrosses. Backcrosses were morphologically similar to their recurrent parent. The lack of developmental instability in hybrids suggests that there are few genetic incompatibilities preventing introgression. Our findings suggest that hybrids are not equal: that is, growth, development, character traits, and morphology differ depending on the genomic contribution from each parental species as well as the hybrid generation.

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

    USGS Publications Warehouse

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

    2004-01-01

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

  15. Examination of the influence of juvenile Atlantic salmon on the feeding mode of juvenile steelhead in Lake Ontario tributaries

    USGS Publications Warehouse

    Johnson, James H.; Waldt, Emily M.

    2014-01-01

    We examined diets of 1204 allopatric and sympatric juvenile Atlantic salmon (Salmo salar) and steelhead (Oncorhynchus mykiss) in three tributaries of Lake Ontario. The diet composition of both species consisted primarily of ephemeropterans, trichopterans, and chironomids, although juvenile steelhead consumed more terrestrial invertebrates, especially at the sympatric sites. Subyearlings of both species consumed small prey (i.e. chironomids) whereas large prey (i.e. perlids) made up a higher percentage of the diet of yearlings. The diet of juvenile steelhead at the allopatric sites was more closely associated with the composition of the benthos than with the drift, but was about equally associated with the benthos and drift at the sympatric sites. The diet of both subyearling and yearling Atlantic salmon was more closely associated with the benthos than the drift at the sympatric sites. The evidence suggests that juvenile steelhead may subtly alter their feeding behavior in sympatry with Atlantic salmon. This behavioral adaptation may reduce competitive interactions between these species.

  16. A blood chemistry profile for lake trout

    USGS Publications Warehouse

    Edsall, Carol Cotant

    1999-01-01

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

  17. Characterize and Quantify Residual Steelhead in the Clearwater River, Idaho, 1999-2000 Progress Report.

    SciTech Connect

    Brostrom, Jody K.

    2006-08-01

    During 1999-2002 we determined whether size at release and release site influenced emigration success and survival of hatchery steelhead smolts raised at Dworshak National Fish Hatchery and released into the Clearwater River drainage. We marked 4,500 smolts each year with Passive Integrated Transponder Tags (PIT-tags) which enabled us to track emigration and estimate survival through mainstem Snake and Columbia river dams. Hatchery steelhead raised in System I freshwater were significantly smaller than those raised in warmer System II re-use water (196 mm, 206 mm, 198 mm and 201 mm System I; 215 mm, 213 mm, 206 mm and 209 mmmore » System II). However, there was no significant difference in detection rates to mainstem observation sites between the two groups (65%, 58%, 78% and 55% System I; 69%, 59%, 74% and 53% System II). Survival estimates to Lower Granite Dam were also not significant between the two groups (72%, 81%, 80% and 77% System I; 77%, 79%, 77%, and 72% System II). Smolts less than 180 mm FL were less likely to be detected than larger smolts. Hatchery steelhead smolts released into Clear Creek, the South Fork Clearwater River and the Clearwater River at Dworshak National Fish Hatchery had significantly different lengths each year, but there was no discernible pattern due to random egg takes and rearing systems. Detection rates to mainstem observation sites for smolts released into Clear Creek were significantly less than the other two groups in all years except 2002 (62%, 57%, 71%, and 57% Clear Creek; 68%, 63%, 73% and 61% South Fork Clearwater River; 70%, 59%, 78% and 55% Clearwater River). However, survival rates to Lower Granite Dam were not significantly different (73%, 65%, 78%, and 77% Clear Creek; 79%, 72%, 79% and 76% South Fork Clearwater River; 81%, 76%, 80% and 83% Clearwater River). Similar to the size at release group, smolts less than 180 mm FL were less likely to get detected than larger smolts. Smolts from both size at release and

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

    USGS Publications Warehouse

    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.

  19. Effect of brook trout removal from a spawning stream on an adfluvial population of Lahontan cutthroat trout

    USGS Publications Warehouse

    Scoppettone, G. Gary; Rissler, Peter H.; Shea, Sean P.; Somer, William

    2012-01-01

    Independence Lake (Nevada and Sierra counties, California) harbors the only extant native population of Lahontan cutthroat trout Oncorhynchus clarkii henshawi in the Truckee River system and one of two extant adfluvial populations in the Lahontan basin. The persistence of this population has been precarious for more than 50 years, with spawning runs consisting of only 30–150 fish. It is assumed that this population was much larger prior to the introduction of nonnative brook trout Salvelinus fontinalis. Brook trout overlap with cutthroat trout in upper Independence Creek, where the cutthroat trout spawn and their resulting progeny emigrate to Independence Lake. In 2005, we began removing brook trout from upper Independence Creek using electrofishers and monitored the cutthroat trout population. Stomach analysis of captured brook trout revealed cutthroat trout fry, and cutthroat trout fry survival increased significantly from 4% to 12% with brook trout removal. Prior to brook trout removal, the only Lahontan cutthroat trout progeny emigrating to Independence Lake were fry; with brook trout removal, juveniles were found entering the lake. In 2010, 237 potential spawners passed a prefabricated weir upstream of Independence Lake. Although the results of this study suggest that brook trout removal from upper Independence Creek has had a positive influence on the population dynamics of Independence Lake Lahontan cutthroat trout, additional years of removal are needed to assess the ultimate effect this action will have upon the cutthroat trout population.

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

    USGS Publications Warehouse

    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.

  1. Effects of seawater acclimation on mRNA levels of corticosteroid receptor genes in osmoregulatory and immune systems in trout

    USGS Publications Warehouse

    Yada, T.; Hyodo, S.; Schreck, C.B.

    2008-01-01

    Influence of environmental salinity on expression of distinct corticosteroid receptor (CR) genes, glucocorticoid receptor (GR)-1 and -2, and mineralcorticoid receptor (MR), was examined in osmoregulatory and hemopoietic organs and leucocytes of steelhead trout (Oncorhynchus mykiss). There was no significant difference in plasma cortisol levels between freshwater (FW)- or seawater (SW)-acclimated trout, whereas Na+, K+-ATPase was activated in gill of SW fish. Plasma lysozyme levels also showed a significant increase after acclimation to SW. In SW-acclimated fish, mRNA levels of GR-1, GR-2, and MR were significantly higher in gill and body kidney than those in FW. Head kidney and spleen showed no significant change in these CR mRNA levels after SW-acclimation. On the other hand, leucocytes isolated from head kidney and peripheral blood showed significant decreases in mRNA levels of CR in SW-acclimated fish. These results showed differential regulation of gene expression of CR between osmoregulatory and immune systems. ?? 2008 Elsevier Inc. All rights reserved.

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

    USGS Publications Warehouse

    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.

  3. Sulfonamide toxicity in brook trout

    USGS Publications Warehouse

    Wood, E.M.; Yasutake, W.T.; Snieszko, S.F.

    1954-01-01

    Sterility was observed in female brook trout that were treated with sulfamerazine at frequent intervals for 2 years to control endemic furunculosis. Feeding sulfamerazine for a period of 8 months caused massive kidney damage similar to that observed in humans who develop allergies to “sulfa” drugs. Kidney damage of the type observed would probably cause renal insufficiency which would handicap any physiological function including reproduction. Feeding sulfonamides for periods up to 13 weeks did not produce kidney damage.

  4. Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Pacific Southwest). Steelhead.

    DTIC Science & Technology

    1986-06-01

    Hunter 1973; Bovee 1978; Wesche and from there make their first upstream Rechard 1980). Intermittent streams migration as half-pounders. are often...young steelhead grew throughout the oxygen demand of organic material in winter (Reeves 1979). the gravel bed (Ponce 1974). Even if embryos hatch at low...Ritchie 1972). Ander- son (1971) reported that sediment The size of substrate material production in northern California has been related by numerous

  5. Potential fitness benefits of the half-pounder life history in Klamath River steelhead

    USGS Publications Warehouse

    Hodge, Brian W.; Wilzbach, Peggy; Duffy, Walter G.

    2014-01-01

    Steelhead Oncorhynchus mykiss from several of the world's rivers display the half-pounder life history, a variant characterized by an amphidromous (and, less often, anadromous) return to freshwater in the year of initial ocean entry. We evaluated factors related to expression of the half-pounder life history in wild steelhead from the lower Klamath River basin, California. We also evaluated fitness consequences of the half-pounder phenotype using a simple life history model that was parameterized with our empirical data and outputs from a regional survival equation. The incidence of the half-pounder life history differed among subbasins of origin and smolt ages. Precocious maturation occurred in approximately 8% of half-pounders and was best predicted by individual length in freshwater preceding ocean entry. Adult steelhead of the half-pounder phenotype were smaller and less fecund at age than adult steelhead of the alternative (ocean contingent) phenotype. However, our data suggest that fish of the half-pounder phenotype are more likely to spawn repeatedly than are fish of the ocean contingent phenotype. Models predicted that if lifetime survivorship were equal between phenotypes, the fitness of the half-pounder phenotype would be 17–28% lower than that of the ocean contingent phenotype. To meet the condition of equal fitness between phenotypes would require that first-year ocean survival be 21–40% higher among half-pounders in freshwater than among their cohorts at sea. We concluded that continued expression of the half-pounder phenotype is favored by precocious maturation and increased survival relative to that of the ocean contingent phenotype.

  6. Hydroacoustic Evaluation of Overwintering Summer Steelhead Fallback and Kelt Passage at The Dalles Dam, 2009-2010

    SciTech Connect

    Khan, Fenton; Johnson, Gary E.; Weiland, Mark A.

    2010-07-31

    This report presents the results of an evaluation of overwintering summer steelhead (Oncorhynchus mykiss) fallback and early out-migrating steelhead kelts downstream passage at The Dalles Dam (TDA) sluiceway and turbines during fall/winter 2009 through early spring 2010. The study was conducted by the Pacific Northwest National Laboratory (PNNL) for the U.S. Army Corps of Engineers, Portland District (USACE). The goal of this study was to characterize adult steelhead spatial and temporal distributions and passage rates at the sluiceway and turbines for fisheries managers and engineers to use in decision-making relative to sluiceway operations. The study was from November 1, 2009more » to April 10, 2010. The study was divided into three study periods: Period 1, November 1 - December 15, 2009 for a fall/winter sluiceway and turbine study; Period 2, December 16, 2009 - February 28, 2010 for a turbine only study; Period 3, March 1 - April 10, 2010 for a spring sluiceway and turbine study. Sluiceway operations were scheduled to begin on March 1 for this study; however, because of an oil spill cleanup near the sluice outfall, sluiceway operations were delayed until March 8, 2010, therefore the spring study period did not commence until March 8. The study objectives were to (1) estimate the number and distribution of overwintering summer steelhead fallbacks and kelt-sized acoustic targets passing into the sluiceway and turbines at TDA between November 1 and December 15, 2009 and March 1 and April 10, 2010, and (2) estimate the numbers and distribution of adult steelhead and kelt-sized targets passing into turbine units between December 16, 2009 and February 28, 2010. We obtained fish passage data using fixed-location hydroacoustics. For Period 1, overwintering summer steelhead fallback occurred throughout the 45-day study period. A total of 879 {+-} 165 (95% CI) steelhead targets passed through the powerhouse and sluiceway during November 1 to December 15, 2009. Ninety

  7. Hydroacoustic Evaluation of Overwintering Summer Steelhead Fallback and Kelt Passage at The Dalles Dam 2008-2009

    SciTech Connect

    Khan, Fenton; Johnson, Gary E.; Weiland, Mark A.

    2009-09-01

    This report presents the results of an evaluation of overwintering summer steelhead (Oncorhynchus mykiss) fallback and early out-migrating steelhead kelts downstream passage at The Dalles Dam (TDA) sluiceway and turbines during fall/winter 2008 and early spring 2009, respectively. The study was conducted by the Pacific Northwest National Laboratory (PNNL) for the U.S. Army Corps of Engineers, Portland District (USACE). Operating the sluiceway reduces the potential for hydropower production. However, this surface flow outlet may be the optimal non-turbine route for fallbacks in late fall after the sluiceway is typically closed for juvenile fish passage and for overwintering summer steelhead andmore » kelt passage in the early spring before the start of the voluntary spill season. The goal of this study was to characterize adult steelhead spatial and temporal distributions and passage rates at the sluiceway and turbines, and their movements in front of the sluiceway at TDA to inform fisheries managers’ and engineers’ decision-making relative to sluiceway operations. The study periods were from November 1 to December 15, 2008 (45 days) and from March 1 to April 9, 2009 (40 days). The study objectives were to 1) estimate the number and distribution of overwintering summer steelhead fallbacks and kelt-sized acoustic targets passing into the sluiceway and turbines at TDA during the two study periods, respectively, and 2) assess the behavior of these fish in front of sluice entrances. We obtained fish passage data using fixed-location hydroacoustics and fish behavior data using acoustic imaging. For the overwintering summer steelhead, fallback occurred throughout the 45-day study period. We estimated that a total of 1790 ± 250 (95% confidence interval) summer steelhead targets passed through the powerhouse intakes and operating sluices during November 1 to December 15, 2008. Ninety five percent of these fish passed through the sluiceway. Therefore, without the

  8. Genetic basis of adult migration timing in anadromous steelhead discovered through multivariate association testing

    PubMed Central

    Zendt, Joseph S.; Matala, Amanda R.; Narum, Shawn R.

    2016-01-01

    Migration traits are presumed to be complex and to involve interaction among multiple genes. We used both univariate analyses and a multivariate random forest (RF) machine learning algorithm to conduct association mapping of 15 239 single nucleotide polymorphisms (SNPs) for adult migration-timing phenotype in steelhead (Oncorhynchus mykiss). Our study focused on a model natural population of steelhead that exhibits two distinct migration-timing life histories with high levels of admixture in nature. Neutral divergence was limited between fish exhibiting summer- and winter-run migration owing to high levels of interbreeding, but a univariate mixed linear model found three SNPs from a major effect gene to be significantly associated with migration timing (p < 0.000005) that explained 46% of trait variation. Alignment to the annotated Salmo salar genome provided evidence that all three SNPs localize within a 46 kb region overlapping GREB1-like (an oestrogen target gene) on chromosome Ssa03. Additionally, multivariate analyses with RF identified that these three SNPs plus 15 additional SNPs explained up to 60% of trait variation. These candidate SNPs may provide the ability to predict adult migration timing of steelhead to facilitate conservation management of this species, and this study demonstrates the benefit of multivariate analyses for association studies. PMID:27170720

  9. Evaluation of angler reporting accuracy in an off-site survey to estimate statewide steelhead harvest

    USGS Publications Warehouse

    McCormick, J. L.; Whitney, D.; Schill, D. J.; Quist, Michael C.

    2015-01-01

    Accuracy of angler-reported data on steelhead, Oncorhynchus mykiss (Walbaum), harvest in Idaho, USA, was quantified by comparing data recorded on angler harvest permits to the numbers that the same group of anglers reported in an off-site survey. Anglers could respond to the off-site survey using mail or Internet; if they did not respond using these methods, they were called on the telephone. A majority of anglers responded through the mail, and the probability of responding by Internet decreased with increasing age of the respondent. The actual number of steelhead harvested did not appear to influence the response type. Anglers in the autumn 2012 survey overreported harvest by 24%, whereas anglers in the spring 2013 survey under-reported steelhead harvest by 16%. The direction of reporting bias may have been a function of actual harvest, where anglers harvested on average 2.6 times more fish during the spring fishery than the autumn. Reporting bias that is a function of actual harvest can have substantial management and conservation implications because the fishery will be perceived to be performing better at lower harvest rates and worse when harvest rates are higher. Thus, these findings warrant consideration when designing surveys and evaluating management actions.

  10. Genetic basis of adult migration timing in anadromous steelhead discovered through multivariate association testing.

    PubMed

    Hess, Jon E; Zendt, Joseph S; Matala, Amanda R; Narum, Shawn R

    2016-05-11

    Migration traits are presumed to be complex and to involve interaction among multiple genes. We used both univariate analyses and a multivariate random forest (RF) machine learning algorithm to conduct association mapping of 15 239 single nucleotide polymorphisms (SNPs) for adult migration-timing phenotype in steelhead (Oncorhynchus mykiss). Our study focused on a model natural population of steelhead that exhibits two distinct migration-timing life histories with high levels of admixture in nature. Neutral divergence was limited between fish exhibiting summer- and winter-run migration owing to high levels of interbreeding, but a univariate mixed linear model found three SNPs from a major effect gene to be significantly associated with migration timing (p < 0.000005) that explained 46% of trait variation. Alignment to the annotated Salmo salar genome provided evidence that all three SNPs localize within a 46 kb region overlapping GREB1-like (an oestrogen target gene) on chromosome Ssa03. Additionally, multivariate analyses with RF identified that these three SNPs plus 15 additional SNPs explained up to 60% of trait variation. These candidate SNPs may provide the ability to predict adult migration timing of steelhead to facilitate conservation management of this species, and this study demonstrates the benefit of multivariate analyses for association studies. © 2016 The Author(s).

  11. Electronic tags and genetics explore variation in migrating steelhead kelts (oncorhynchus mykiss), Ninilchik river, Alaska

    USGS Publications Warehouse

    Nielsen, J.L.; Turner, S.M.; Zimmerman, C.E.

    2011-01-01

    Acoustic and archival tags examined freshwater and marine migrations of postspawn steelhead kelts (Oncorhynchus mykiss) in the Ninilchik River, Alaska, USA. Postspawn steelhead were captured at a weir in 2002-2005. Scale analysis indicated multiple migratory life histories and spawning behaviors. Acoustic tags were implanted in 99 kelts (2002-2003), and an array of acoustic receivers calculated the average speed of outmigration, timing of saltwater entry, and duration of residency in the vicinity of the river mouth. Ocean migration data were recovered from two archival tags implanted in kelts in 2004 (one male and one female). Archival tags documented seasonal differences in maximum depth and behavior with both fish spending 97% of time at sea <6 m depth (day and night). All study fish were double tagged with passive integrated transponder (PIT) tags implanted in the body cavity. Less than 4% of PIT tags were retained in postspawn steelhead. Molecular genetics demonstrated no significant differences in genetic population structure across years or among spawning life history types, suggesting a genetically panmictic population with highly diverse life history characteristics in the Ninilchik River.

  12. Bull trout recovery: Monitoring and evaluation guidance

    Treesearch

    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...

  13. Some problems of private trout hatchery operators

    USGS Publications Warehouse

    Rucker, Robert R.

    1957-01-01

    Disease, nutritional, and environmental problems in commercial production of trout are discussed, including mortality and age of spawners, copepod and gyrodactylid infections, suitable water temperatures, diseases (especially red mouth and back peel) and inspection of fish. It is concluded that experiences with hatchery procedures have varied greatly and often the commercial trout producer must adjust methods to fit his particular needs and conditions.

  14. Conservation status of Colorado River cutthroat trout

    Treesearch

    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...

  15. Have brook trout (Salvelinus fontinalis) displaced bull trout (Salvelinus confluentus) along longitudinal gradients in central Idaho streams?

    Treesearch

    Bruce E. Rieman; James T. Peterson; Deborah L. Myers

    2006-01-01

    Invasions of non-native brook trout (Salvelinus fontinalis) have the potential for upstream displacement or elimination of bull trout (Salvelinus confluentus) and other native species already threatened by habitat loss. We summarized the distribution and number of bull trout in samples from 12 streams with and without brook trout...

  16. Capture, marking, and enumeration of juvenile bull trout and cutthroat trout in small, low-conductivity streams

    Treesearch

    Joseph L. Bonneau; Russell F. Thurow; Dennis L. Scarnecchia

    1995-01-01

    Relative efficiencies of sampling methods were evaluated for bull trout Salvefinus confluentus and cutthroat trout Oncorhynchus clarki in small, high-gradient streams with low conductivities. We compared day and nighttime observations by snorkelers to enumerate bull trout and cutthroat trout, and at night we also used a bank observer. Methods were developed for...

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

    Treesearch

    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...

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

    USGS Publications Warehouse

    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.

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

    SciTech Connect

    Olson, Jason; Maroney, Joseph R.; Andersen, Todd

    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)more » and westslope cutthroat trout (with Yellowstone cutthroat trout and rainbow trout) in the Priest Lake and Lower Pend Oreille subbasins will also be examined.« less

  20. Pettit and Kuipers in a run of the SPHERES ZR

    NASA Image and Video Library

    2012-01-23

    ISS030-E-047176 (23 Jan. 2012) --- In the International Space Station?s Kibo laboratory, NASA astronaut Don Pettit (left) and European Space Agency astronaut Andre Kuipers, both Expedition 30 flight engineers, support competing students on the ground in a run of the Synchronized Position Hold, Engage, Reorient, Experimental Satellites Zero Robotics (SPHERES ZR) experiment.

  1. Hydroacoustic Evaluation of Overwintering Summer Steelhead Fallback and Kelt Passage at The Dalles Dam Turbines, Early Spring 2011

    SciTech Connect

    Khan, Fenton; Royer, Ida M.

    2012-02-01

    This report presents the results of an evaluation of overwintering summer steelhead (Oncorhynchus mykiss) fallback and early out-migrating steelhead kelts downstream passage at The Dalles Dam turbines during early spring 2011. The study was conducted by Pacific Northwest National Laboratory (PNNL) for the U.S. Army Corps of Engineers, Portland District (USACE) to investigate whether adult steelhead are passing through turbines during early spring before annual sluiceway operations typically begin. The sluiceway surface flow outlet is the optimal non-turbine route for adult steelhead, although operating the sluiceway reduces hydropower production. This is a follow-up study to similar studies of adult steelheadmore » passage at the sluiceway and turbines we conducted in the fall/winter 2008, early spring 2009, fall/winter 2009, and early spring 2010. The goal of the 2011 study was to characterize adult steelhead passage rates at the turbines while the sluiceway was closed so fisheries managers would have additional information to use in decision-making relative to sluiceway operations. Sluiceway operations were not scheduled to begin until April 10, 2011. However, based on a management decision in late February, sluiceway operations commenced on March 1, 2011. Therefore, this study provided estimates of fish passage rates through the turbines, and not the sluiceway, while the sluiceway was open. The study period was March 1 through April 10, 2011 (41 days total). The study objective was to estimate the number and distribution of adult steelhead and kelt-sized targets passing into turbine units. We obtained fish passage data using fixed-location hydroacoustics with transducers deployed at all 22 main turbine units at The Dalles Dam. Adult steelhead passage through the turbines occurred on 9 days during the study (March 9, 12, 30, and 31 and April 2, 3, 5, 7, and 9). We estimated a total of 215 {+-} 98 (95% confidence interval) adult steelhead targets passed through

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

    USGS Publications Warehouse

    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.

  3. Behavior of steelhead fry in a laboratory stream is affected by fish density but not rearing environment

    USGS Publications Warehouse

    Riley, Stephen C.; Tatara, Christopher P.; Berejikian, Barry A.; Flagg, Thomas A.

    2009-01-01

    We quantified the aggression, feeding, dominance, position choice, and territory size of naturally reared steelhead Oncorhynchus mykiss fry stocked with two types of hatchery-reared fry (from conventional and enriched rearing environments) at two densities in experimental flumes to determine how rearing environment and fish density affect the behavior of steelhead fry. We found that fry density had a significant effect on most response variables but that rearing treatment did not. The rates of threats and attacks were positively correlated with fry density, but the overall feeding rate was negatively correlated. Naturally reared fry were dominant more often at low densities, and hatchery-reared fry were dominant more often at high densities. There were no significant effects of hatchery rearing treatment on aggression, feeding, dominance, or territory size. The only significant effect of rearing treatment was on the position of naturally reared fry, which occupied more upstream positions when stocked with conventional than with enriched hatchery-reared fry. Overall, rearing environment had relatively little influence on the behavior of steelhead fry. Our results indicate that stocking hatchery-reared steelhead fry at low densities may have effects on similar-size wild fish comparable to an equivalent increase in the density of wild fish. We suggest that releasing hatchery-reared steelhead fry as a supplementation strategy may have few direct negative ecological effects on wild fry.

  4. Evidence of sex-bias in gene expression in the brain transcriptome of two populations of rainbow trout (Oncorhynchus mykiss) with divergent life histories.

    PubMed

    Hale, Matthew C; McKinney, Garrett J; Thrower, Frank P; Nichols, Krista M

    2018-01-01

    Sex-bias in gene expression is a mechanism that can generate phenotypic variance between the sexes, however, relatively little is known about how patterns of sex-bias vary during development, and how variable sex-bias is between different populations. To that end, we measured sex-bias in gene expression in the brain transcriptome of rainbow trout (Oncorhynchus mykiss) during the first two years of development. Our sampling included from the fry stage through to when O. mykiss either migrate to the ocean or remain resident and undergo sexual maturation. Samples came from two F1 lines: One from migratory steelhead trout and one from resident rainbow trout. All samples were reared in a common garden environment and RNA sequencing (RNA-seq) was used to estimate patterns of gene expression. A total of 1,716 (4.6% of total) genes showed evidence of sex-bias in gene expression in at least one time point. The majority (96.7%) of sex-biased genes were differentially expressed during the second year of development, indicating that patterns of sex-bias in expression are tied to key developmental events, such as migration and sexual maturation. Mapping of differentially expressed genes to the O. mykiss genome revealed that the X chromosome is enriched for female upregulated genes, and this may indicate a lack of dosage compensation in rainbow trout. There were many more sex-biased genes in the migratory line than the resident line suggesting differences in patterns of gene expression in the brain between populations subjected to different forces of selection. Overall, our results suggest that there is considerable variation in the extent and identity of genes exhibiting sex-bias during the first two years of life. These differentially expressed genes may be connected to developmental differences between the sexes, and/or between adopting a resident or migratory life history.

  5. Lake trout rehabilitation in Lake Huron

    USGS Publications Warehouse

    Eshenroder, Randy L.; Payne, N. Robert; Johnson, James E.; Bowen, Charles; Ebener, Mark P.

    1995-01-01

    Efforts to restore lake trout (Salvelinus namaycush) in Lake Huron after their collapse in the 1940s were underway in the early 1970s with completion of the first round of lampricide applications in tributary streams and the stocking of several genotypes. We assess results of rehabilitation and establish a historical basis for comparison by quantifying the catch of spawning lake trout from Michigan waters in 1929-1932. Sixty-eight percent of this catch occurred in northern waters (MH-1) and most of the rest (15%) was from remote reefs in the middle of the main basin. Sea lampreys (Petromyzon marinus) increased in the early 1980s in the main basin and depressed spawning populations of lake trout. This increase was especially severe in northern waters and appeared to be associated with untreated populations in the St. Marys River. Excessive commercial fishing stemming from unresolved treaty rights also contributed to loss of spawning fish in northern Michigan waters. Seneca-strain lake trout did not appear to be attacked by sea lampreys until they reached a size > 532 mm. At sizes > 632 mm, Seneca trout were 40-fold more abundant than the Marquette strain in matched-planting experiments. Natural reproduction past the fry stage has occurred in Thunder Bay and South Bay, but prospects for self-sustaining populations of lake trout in the main basin are poor because sea lampreys are too abundant, only one side of the basin is stocked, and stocking is deferred to allow commercial gillnetting in areas where most of the spawning occurred historically. Backcross lake trout, a lake trout x splake (s. Fontinalis x s. Namaycush) hybrid, did not reproduce in Georgian Bay, but this genotype is being replaced with pure-strain lake trout, whose early performance appears promising.

  6. Diagnostic single nucleotide polymorphisms for identifying westslope cutthroat trout (Oncorhynchus clarki lewisi), Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) and rainbow trout (Oncorhynchus mykiss).

    PubMed

    Kalinowski, S T; Novak, B J; Drinan, D P; Jennings, R deM; Vu, N V

    2011-03-01

    We describe 12 diagnostic single nucleotide polymorphism (SNP) assays for use in species identification among rainbow and cutthroat trout: five of these loci have alleles unique to rainbow trout (Oncorhynchus mykiss), three unique to westslope cutthroat trout (O. clarkii lewisi) and four unique to Yellowstone cutthroat trout (O. clarkii bouvieri). These diagnostic assays were identified using a total of 489 individuals from 26 populations and five fish hatchery strains. © 2010 Blackwell Publishing Ltd.

  7. Ecosystem experiment reveals benefits of natural and simulated beaver dams to a threatened population of steelhead (Oncorhynchus mykiss).

    PubMed

    Bouwes, Nicolaas; Weber, Nicholas; Jordan, Chris E; Saunders, W Carl; Tattam, Ian A; Volk, Carol; Wheaton, Joseph M; Pollock, Michael M

    2016-07-04

    Beaver have been referred to as ecosystem engineers because of the large impacts their dam building activities have on the landscape; however, the benefits they may provide to fluvial fish species has been debated. We conducted a watershed-scale experiment to test how increasing beaver dam and colony persistence in a highly degraded incised stream affects the freshwater production of steelhead (Oncorhynchus mykiss). Following the installation of beaver dam analogs (BDAs), we observed significant increases in the density, survival, and production of juvenile steelhead without impacting upstream and downstream migrations. The steelhead response occurred as the quantity and complexity of their habitat increased. This study is the first large-scale experiment to quantify the benefits of beavers and BDAs to a fish population and its habitat. Beaver mediated restoration may be a viable and efficient strategy to recover ecosystem function of previously incised streams and to increase the production of imperiled fish populations.

  8. Ecosystem experiment reveals benefits of natural and simulated beaver dams to a threatened population of steelhead (Oncorhynchus mykiss)

    PubMed Central

    Bouwes, Nicolaas; Weber, Nicholas; Jordan, Chris E.; Saunders, W. Carl; Tattam, Ian A.; Volk, Carol; Wheaton, Joseph M.; Pollock, Michael M.

    2016-01-01

    Beaver have been referred to as ecosystem engineers because of the large impacts their dam building activities have on the landscape; however, the benefits they may provide to fluvial fish species has been debated. We conducted a watershed-scale experiment to test how increasing beaver dam and colony persistence in a highly degraded incised stream affects the freshwater production of steelhead (Oncorhynchus mykiss). Following the installation of beaver dam analogs (BDAs), we observed significant increases in the density, survival, and production of juvenile steelhead without impacting upstream and downstream migrations. The steelhead response occurred as the quantity and complexity of their habitat increased. This study is the first large-scale experiment to quantify the benefits of beavers and BDAs to a fish population and its habitat. Beaver mediated restoration may be a viable and efficient strategy to recover ecosystem function of previously incised streams and to increase the production of imperiled fish populations. PMID:27373190

  9. Angler harvest, hatchery return, and tributary stray rates of recycled adult summer steelhead Oncorhynchus mykiss in the Cowlitz River, Washington

    USGS Publications Warehouse

    Kock, Tobias J.; Perry, Russell W.; Gleizes, Chris; Dammers, Wolf; Liedtke, Theresa L.

    2016-01-01

    Hatchery ‘recycling’ programs have been used to increase angling opportunities by re-releasing fish into a river after they returned to a hatchery or fish trap. Recycling is intended to increase opportunities for fishermen, but this strategy could affect wild fish populations if some recycled fish remain in the river and interact with wild fish populations. To quantify hatchery return and angler harvest rates of recycled steelhead, we conducted a 2-year study on the Cowlitz River, Washington. A total of 1051 steelhead were recycled, including 218 fish that were radio-tagged. Fates of recycled steelhead were similar between years: 48.4% returned to the hatchery, 19.2% were reported captured by anglers, and 32.4% remained in the river. A multistate model quantified the effects of covariates on hatchery return and angler harvest rates, which were positively affected by river discharge and negatively affected by time since release. However, hatchery return rates increased and angler harvest rates decreased during periods of increasing discharge. A total of 21.1% (46 fish) of the radio-tagged steelhead failed to return to the hatchery or be reported by anglers, but nearly half of those fish (20 fish) appeared to be harvested and not reported. The remaining tagged fish (11.9% of the radio-tagged population) were monitored into the spawning period, but only five fish (2.3% of the radio-tagged population) entered tributaries where wild steelhead spawning occurs. Future research focused on straying behaviour, and spawning success of recycled steelhead may further advance the understanding of the effects of recycling as a management strategy.

  10. Transcription profiling in environmental diagnostics: health assessments in Columbia River basin steelhead (Oncorhynchus mykiss).

    PubMed

    Connon, Richard E; D'Abronzo, Leandro S; Hostetter, Nathan J; Javidmehr, Alireza; Roby, Daniel D; Evans, Allen F; Loge, Frank J; Werner, Inge

    2012-06-05

    The health condition of out-migrating juvenile salmonids can influence migration success. Physical damage, pathogenic infection, contaminant exposure, and immune system status can affect survival probability. The present study is part of a wider investigation of out-migration success in juvenile steelhead (Oncorhynchus mykiss) and focuses on the application of molecular profiling to assess sublethal effects of environmental stressors in field-collected fish. We used a suite of genes in O. mykiss to specifically assess responses that could be directly related to steelhead health condition during out-migration. These biomarkers were used on juvenile steelhead captured in the Snake River, a tributary of the Columbia River, in Washington, USA, and were applied on gill and anterior head kidney tissue to assess immune system responses, pathogen-defense (NRAMP, Mx, CXC), general stress (HSP70), metal-binding (metallothionein-A), and xenobiotic metabolism (Cyp1a1) utilizing quantitative polymerase chain reaction (PCR) technology. Upon capture, fish were ranked according to visual external physical conditions into good, fair, poor, and bad categories; gills and kidney tissues were then dissected and preserved for gene analyses. Transcription responses were tissue-specific for gill and anterior head kidney with less significant responses in gill tissue than in kidney. Significant differences between the condition ranks were attributed to NRAMP, MX, CXC, and Cyp1a1 responses. Gene profiling correlated gene expression with pathogen presence, and results indicated that gene profiling can be a useful tool for identifying specific pathogen types responsible for disease. Principal component analysis (PCA) further correlated these responses with specific health condition categories, strongly differentiating good, poor, and bad condition ranks. We conclude that molecular profiling is an informative and useful tool that could be applied to indicate and monitor numerous population

  11. Hepatic effects of acrylamide in rainbow trout.

    PubMed

    Petersen, D W; Lech, J J

    1987-06-30

    Acrylamide effects on hepatic mixed function oxidase activity were examined in rainbow trout exposed to waterborne acrylamide monomer (0-50 mg/liter) for 14 days. Acrylamide doses of 25 mg/liter and higher produced reversible dose-related histological lesions in the liver characterized by necrosis around the central vein. A profound selective decrease in ethoxyresorufin-O-deethylase activity was observed in hepatic microsomes from acrylamide-treated trout. However, in vitro preincubation of acrylamide with untreated rainbow trout hepatic microsomes with or without NADPH did not produce a similar decrease in ethoxyresorufin-O-deethylase activity. Structural analysis of a trout biliary metabolite of acrylamide, although not identified, revealed the presence of primary alcohol, carboxylic acid, and amide carbonyl functional groups.

  12. Longevity of Lake Superior lake trout

    USGS Publications Warehouse

    Schram, Stephen T.; Fabrizio, Mary C.

    1998-01-01

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

  13. Survival and Passage of Yearling and Subyearling Chinook Salmon and Steelhead at The Dalles Dam, 2010

    SciTech Connect

    Johnson, Gary E.; Skalski, J. R.; Carlson, Thomas J.

    2011-12-01

    The acoustic telemetry study reported here was conducted by researchers at Pacific Northwest National Laboratory (PNNL) and the University of Washington (UW) for the U.S. Army Corps of Engineers, Portland District (USACE). The purpose of the study was to estimate dam passage survival and other performance measures for yearling and subyearling Chinook salmon and steelhead at The Dalles Dam as stipulated by the 2008 Biological Opinion on operation of the Federal Columbia River Power System (FCRPS) and 2008 Columbia Basin Fish Accords.

  14. Genetic strategies for lake trout rehabilitation: a synthesis

    USGS Publications Warehouse

    Burnham-Curtis, Mary K.; Krueger, Charles C.; Schreiner, Donald R.; Johnson, James E.; Stewart, Thomas J.; Horrall, Ross M.; MacCallum, Wayne R.; Kenyon, Roger; Lange, Robert E.

    1995-01-01

    The goal of lake trout rehabilitation efforts in the Great Lakes has been to reestablish inshore lake trout (Salvelinus namaycush) populations to self-sustaining levels. A combination of sea lamprey control, stocking of hatchery-reared lake trout, and catch restrictions were used to enhance remnant lake trout stocks in Lake Superior and reestablish lake trout in Lakes Michigan, Huron, Erie, and Ontario. Genetic diversity is important for the evolution and maintenance of successful adaptive strategies critical to population restoration. The loss of genetic diversity among wild lake trout stocks in the Great Lakes imposes a severe constraint on lake trout rehabilitation. The objective of this synthesis is to address whether the particular strain used for stocking combined with the choice of stocking location affects the success or failure of lake trout rehabilitation. Poor survival, low juvenile recruitment, and inefficient habitat use are three biological impediments to lake trout rehabilitation that can be influenced by genetic traits. Evidence supports the hypothesis that the choices of appropriate lake trout strain and stocking locations enhance the survival of lake trout stocked into the Great Lakes. Genetic strategies proposed for lake trout rehabilitation include conservation of genetic diversity in remnant stocks, matching of strains with target environments, stocking a greater variety of lake trout phenotypes, and rehabilitation of diversity at all trophic levels.

  15. Movement and survival of brown trout and rainbow trout in an ozark tailwater river

    USGS Publications Warehouse

    Quinn, J.W.; Kwak, T.J.

    2011-01-01

    We evaluated the movement of adult brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss in relation to a catch-andrelease area in the White River downstream from Beaver Dam, Arkansas. Nine fish of each species were implanted with radio transmitters and monitored from July 1996 to July 1997. The 1.5- km river length of a catch-and-release area (closed to angler harvest) was greater than the total linear range of 72% of the trout (13 of 18 fish), but it did not include two brown trout spawning riffles, suggesting that it effectively protects resident fish within the catch-and-release area except during spawning. The total detected linear range of movement varied from 172 to 3,559 m for brown trout and from 205 to 3,023mfor rainbow trout. The movements of both species appeared to be generally similar to that in unregulated river systems. The annual apparent survival of both trout species was less than 0.40, and exploitation was 44%.Management to protect fish on spawning riffles may be considered if management for wild brown trout becomes a priority. ?? American Fisheries Society 2011.

  16. Patterns of hybridization among cutthroat trout and rainbow trout in northern Rocky Mountain streams

    Treesearch

    Kevin S. McKelvey; Michael K. Young; Taylor M. Wilcox; Daniel M. Bingham; Kristine L. Pilgrim; Michael K. Schwartz

    2016-01-01

    Introgressive hybridization between native and introduced species is a growing conservation concern. For native cutthroat trout and introduced rainbow trout in western North America, this process is thought to lead to the formation of hybrid swarms and the loss of monophyletic evolutionary lineages. Previous studies of this phenomenon, however, indicated that...

  17. Livestock Grazing, Golden Trout, and Streams in the Golden Trout Wilderness, California: Impacts and Management Implications

    Treesearch

    R. Knapp; K. Matthews

    1996-01-01

    Impacts of livestock grazing on California golden trout Oncorhynchus rnykiss aguabonita and their habitat were studied inside and outside of livestock exclosures in the Golden Trout Wilderness, California. In two consecutive years, the majority of stream physical characteristics showed large differences between grazed and ungrazed areas, and the directions of these...

  18. 1-D blood flow modelling in a running human body.

    PubMed

    Szabó, Viktor; Halász, Gábor

    2017-07-01

    In this paper an attempt was made to simulate blood flow in a mobile human arterial network, specifically, in a running human subject. In order to simulate the effect of motion, a previously published immobile 1-D model was modified by including an inertial force term into the momentum equation. To calculate inertial force, gait analysis was performed at different levels of speed. Our results show that motion has a significant effect on the amplitudes of the blood pressure and flow rate but the average values are not effected significantly.

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

    USGS Publications Warehouse

    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.

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

    USGS Publications Warehouse

    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.

  1. Feed characteristics alter growth efficiency of cutthroat trout

    USDA-ARS?s Scientific Manuscript database

    The shift in commercial Rainbow Trout Oncorhynchus mykiss diet formulations toward formulations with more plant ingredient inclusion, and specifically increased soy product inclusion, may have negative implications for less domesticated trout species fed these modern diets. Therefore, the objective ...

  2. Scale-dependent seasonal pool habitat use by sympatric Wild Brook Trout and Brown Trout populations

    USGS Publications Warehouse

    Davis, Lori A.; Wagner, Tyler

    2016-01-01

    Sympatric populations of native Brook Trout Salvelinus fontinalis and naturalized Brown Trout Salmo truttaexist throughout the eastern USA. An understanding of habitat use by sympatric populations is of importance for fisheries management agencies because of the close association between habitat and population dynamics. Moreover, habitat use by stream-dwelling salmonids may be further complicated by several factors, including the potential for fish to display scale-dependent habitat use. 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) assess the sensitivity of inferred habitat use to changes in the spatial scale of the assumed available habitat. Trout exhibited an overall preference for pool habitats over nonpool habitats; however, the use of pools was nonlinear over time. Brook Trout displayed a greater preference for deep residual pool habitats than for shallow pool and nonpool habitats, whereas Brown Trout selected for all pool habitat categories similarly. Habitat use by both species was found to be scale dependent. At the smallest spatial scale (50 m), habitat use was primarily related to the time of year and fish weight. However, at larger spatial scales (250 and 450 m), habitat use varied over time according to the study stream in which a fish was located. Scale-dependent relationships in seasonal habitat use by Brook Trout and Brown Trout highlight the importance of considering scale when attempting to make inferences about habitat use; fisheries managers may want to consider identifying the appropriate spatial scale when devising actions to restore and protect Brook Trout populations and their habitats.

  3. 2016 Lake Michigan Lake Trout Working Group Report

    USGS Publications Warehouse

    Madenjian, Charles P.; Breidert, Brian; Boyarski, David; Bronte, Charles R.; Dickinson, Ben; Donner, Kevin; Ebener, Mark P.; Gordon, Roger; Hanson, Dale; Holey, Mark; Janssen, John; Jonas, Jory; Kornis, Matthew; Olsen, Erik; Robillard, Steve; Treska, Ted; Weldon, Barry; Wright, Greg D.

    2017-01-01

    This report provides a review on the progression of lake trout rehabilitation towards meeting the Salmonine Fish Community Objectives (FCOs) for Lake Michigan (Eshenroder et. al. 1995) and the interim goal and evaluation objectives articulated in A Fisheries Management Implementation Strategy for the Rehabilitation of Lake Trout in Lake Michigan (Dexter et al. 2011); we also include data describing lake trout stocking and mortality to portray the present state of progress towards lake trout rehabilitation.

  4. Monitoring of Juvenile Yearling Chinook Salmon and Steelhead Survival and Passage at Bonneville Dam, Spring 2010

    SciTech Connect

    Ploskey, Gene R.; Faber, Derrek M.; Weiland, Mark A.

    2012-09-01

    The purpose of this study was to estimate the survival for yearling Chinook salmon and steelhead smolts during spring 2010 in a portion of the Columbia River that includes Bonneville Dam. The study estimated smolt survival from a virtual release at Bonneville Dam to a survival array 81 km downstream of Bonneville Dam. We also estimated median forebay residence time, median tailrace egress time, and spill passage efficiency (SPE), as required in the Columbia Basin Fish Accords. A single release design was used to estimate survival from Bonneville Dam to a primary array located 81 km downstream of Bonneville. Themore » approach did not include a reference tailrace release. Releases of acoustic-tagged smolts above John Day Dam to Hood River contributed to the formation of virtual releases at a Bonneville Dam forebay entrance array and at the face of the dam. A total of 3,880 yearling Chinook salmon and 3,885 steelhead smolts were tagged and released in the investigation. The Juvenile Salmon Acoustic Telemetry System (JSATS) tag model number ATS-156dB, weighing 0.438 g in air, was used in this investigation.« less

  5. Monitoring of Juvenile Yearling Chinook Salmon and Steelhead Survival and Passage at Bonneville Dam, Spring 2010

    SciTech Connect

    Ploskey, Gene R.; Faber, Derrek M.; Weiland, Mark A.

    2011-02-01

    The purpose of this study was to estimate the survival for yearling Chinook salmon and steelhead smolts during spring 2010 in a portion of the Columbia River that includes Bonneville Dam. The study estimated smolt survival from a virtual release at Bonneville Dam to a survival array 81 km downstream of Bonneville Dam. We also estimated median forebay residence time, median tailrace egress time, and spill passage efficiency (SPE), as required in the Columbia Basin Fish Accords. A single release design was used to estimate survival from Bonneville Dam to a primary array located 81 km downstream of Bonneville. Themore » approach did not include a reference tailrace release. Releases of acoustic-tagged smolts above John Day Dam to Hood River contributed to the formation of virtual releases at a Bonneville Dam forebay entrance array and at the face of the dam. A total of 3,880 yearling Chinook salmon and 3,885 steelhead smolts were tagged and released in the investigation. The Juvenile Salmon Acoustic Telemetry System (JSATS) tag model number ATS-156dB, weighing 0.438 g in air, was used in this investigation.« less

  6. Broodstock History Strongly Influences Natural Spawning Success in Hatchery Steelhead (Oncorhynchus mykiss).

    PubMed

    Ford, Michael J; Murdoch, Andrew R; Hughes, Michael S; Seamons, Todd R; LaHood, Eric S

    2016-01-01

    We used genetic parentage analysis of 6200 potential parents and 5497 juvenile offspring to evaluate the relative reproductive success of hatchery and natural steelhead (Onchorhynchus mykiss) when spawning in the wild between 2008 and 2011 in the Wenatchee River, Washington. Hatchery fish originating from two prior generation hatchery parents had <20% of the reproductive success of natural origin spawners. In contrast, hatchery females originating from a cross between two natural origin parents of the prior generation had equivalent or better reproductive success than natural origin females. Males originating from such a cross had reproductive success of 26-93% that of natural males. The reproductive success of hatchery females and males from crosses consisting of one natural origin fish and one hatchery origin fish was 24-54% that of natural fish. The strong influence of hatchery broodstock origin on reproductive success confirms similar results from a previous study of a different population of the same species and suggests a genetic basis for the low reproductive success of hatchery steelhead, although environmental factors cannot be entirely ruled out. In addition to broodstock origin, fish size, return time, age, and spawning location were significant predictors of reproductive success. Our results indicate that incorporating natural fish into hatchery broodstock is clearly beneficial for improving subsequent natural spawning success, even in a population that has a decades-long history of hatchery releases, as is the case in the Wenatchee River.

  7. Evaluation of strobe lights to reduce turbine entrainment of juvenile steelhead (Oncorhynchus mykiss) at Cowlitz Falls Dam, Washington

    USGS Publications Warehouse

    Kock, Tobias J.; Evans, Scott D.; Liedtke, Theresa L.; Rondorf, Dennis W.; Kohn, Mike

    2009-01-01

    We conducted a radiotelemetry evaluation to determine if strobe lights could be used to decrease turbine entrainment of juvenile steelhead (Oncorhynchus mykiss) at Cowlitz Falls Dam, Washington. We found that radio-tagged juvenile steelhead approached and entered two spillbays (one lighted, one unlighted) in equal proportions. However, the presence of strobe lights was associated with decreased spillbay residence time of juvenile steelhead and increased passage through induction slots (secondary turbine intakes located upstream of the ogee on the spillway). Mean residence time of tagged fish inside the lighted spillbay was 14 min compared to 62 min inside the unlighted spillbay. Radio-tagged steelhead passed through induction slots at a higher proportion in the lighted spillbay (55%) than in the unlighted spillbay (26%). Recent studies have suggested that strobe lights can induce torpor in juvenile salmonids. We believe that strobe light exposure affected fish in our study at a location where they were susceptible to high flows thereby reducing mean residence time and increasing the proportion of tagged fish entering induction slots in the lighted spillbay. Our results suggest that factors such as deployment location, exposure, and flow are important variables that should be considered when evaluating strobe lights as a potential fish-deterring management tool.

  8. Microsatellite diversity in sympatric reproductive ecotypes of pacific steelhead (Oncorhynchus mykiss) from the Middle Fork Eel River, California

    USGS Publications Warehouse

    Nielsen, J.L.; Fountain, Monique C.

    1999-01-01

    Genetic differentiation between two reproductive ecotypes of anadromous steelhead found in the Middle Fork Eel River in northern California was tested using 16 microsatellite loci. Twelve of these loci showed significant differences in allelic frequency between the two Middle Fork Eel River steelhead populations (Fisher's exact P<0.05). Fisher's combined test for independence also supported significant genetic separation between the two reproductive ecotype (P<0.001). Analysis of molecular variance indicated that only 1% of the overall microsatellite allelic variation contributed to differences between summer- and winter-run steelhead in the Middle Fork Eel River. Variation found among individuals within the two runs equaled 18.2%. Analyses showed less genetic distance between the two populations of steelhead in the Middle Fork Eel River than in comparisons made with geographically proximate coastal winter-run fish. Divergence time based on genetic distance for the two within-basin reproductive ecotypes was estimated to be 16,000-28,000 years ago.

  9. Compliance Monitoring of Juvenile Yearling Chinook Salmon and Steelhead Survival and Passage at The Dalles Dam, Spring 2011

    SciTech Connect

    Skalski, John R.; Townsend, Richard L.; Seaburg, Adam

    2012-06-12

    The study estimated dam passage survival at The Dalles Dam as stipulated by the 2008 Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp) and provided additional performance measures as stipulated in the Columbia Basin Fish Accords. This summary report focuses on spring run stocks, yearling Chinook salmon and steelhead.

  10. Compliance Monitoring of Juvenile Yearling Chinook Salmon and Steelhead Survival and Passage at The Dales Dam, Spring 2011

    SciTech Connect

    Skalski, John R.; Townsend, Richard L.; Seaburg, Adam

    2012-02-01

    The study estimated dam passage survival at The Dalles Dam as stipulated by the 2008 Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp) and provided additional performance measures as stipulated in the Columbia Basin Fish Accords. This summary report focuses on spring run stocks, yearling Chinook salmon and steelhead.

  11. 50 CFR 226.212 - Critical habitat for 13 Evolutionarily Significant Units (ESUs) of salmon and steelhead...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Critical habitat for 13 Evolutionarily Significant Units (ESUs) of salmon and steelhead (Oncorhynchus spp.) in Washington, Oregon and Idaho. 226.212 Section 226.212 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF...

  12. Biology and management of threatened and endangered western trouts

    Treesearch

    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

    USDA-ARS?s Scientific Manuscript database

    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. Performance of a surface bypass structure to enhance juvenile steelhead passage and survival at Lower Granite Dam, Washington

    USGS Publications Warehouse

    Adams, Noah S.; Plumb, John M.; Perry, Russell W.; Rondorf, Dennis W.

    2014-01-01

    An integral part of efforts to recover stocks of Pacific salmon Oncorhynchus spp. and steelhead O. mykiss in Pacific Northwest rivers is to increase passage efficacy and survival of juveniles past hydroelectric dams. As part of this effort, we evaluated the efficacy of a prototype surface bypass structure, the removable spillway weir (RSW), installed in a spillbay at Lower Granite Dam, Washington, on the Snake River during 2002, 2003, 2005, and 2006. Radio-tagged juvenile steelhead were released upstream from the dam and their route of passage through the turbines, juvenile bypass, spillway, or RSW was recorded. The RSW was operated in an on-or-off condition and passed 3–13% of the total discharge at the dam when it was on. Poisson rate models were fit to the passage counts of hatchery- and natural-origin juvenile steelhead to predict the probability of fish passing the dam. Main-effect predictor variables were RSW operation, diel period, day of the year, proportion of flow passed by the spillway, and total discharge at the dam. The combined fish passage through the RSW and spillway was 55–85% during the day and 37–61% during the night. The proportion of steelhead passing through nonturbine routes was <88% when the RSW was off during the day and increased to >95% when the RSW was on during the day. The ratio of the proportion of steelhead passed to the proportion of water passing the RSW was from 6.3:1 to 10.0:1 during the day and from 2.7:1 to 5.2:1 during the night. Steelhead passing through the RSW exited the tailrace about 15 min faster than fish passing through the spillway. Mark–recapture single-release survival estimates for steelhead passing the RSW ranged from 0.95 to 1.00. The RSW appeared to be an effective bypass structure compared with other routes of fish passage at the dam.

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

    USGS Publications Warehouse

    Benjamin, Joseph R.; Heltzel, Jeannie; Dunham, Jason B.; 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

  16. Snorkeling as an alternative to depletion electrofishing for assessing cutthroat trout and brown trout in stream pools

    USGS Publications Warehouse

    Joyce, M.P.; Hubert, W.A.

    2003-01-01

    We compared abundance and length structure estimates of cutthroat trout (Oncorhynchus clarki) and brown trout (Salmo trutta) of 15 cm total length or greater obtained by snorkeling in stream pools with estimates obtained by depletion electrofishing. We sampled 12 pools in each of two streams formed by large springs in the Salt River Valley of western Wyoming. Snorkeling counts provided a relatively accurate index of depletion electrofishing estimates of abundance of cutthroat trout, but not brown trout. Linear regression analysis showed that snorkeling counts were significantly related to depletion electrofishing estimates for both cutthroat trout (P < 0.001) and brown trout (P = 0.002), but the coefficient of determination for brown trout (r2 = 0.33) was low compared to cutthroat trout (r2 = 0.95). Frequencies of fish in three length classes observed by snorkeling and depletion electrofishing were close to being significantly different for cutthroat trout (P = 0.066) and substantially different for brown trout (P = 0.005). Snorkeling frequently failed to observe fish in the shortest length class (15-29 cm total length) of both cutthroat trout and brown trout.

  17. A Floating Bridge Disrupts Seaward Migration and Increases Mortality of Steelhead Smolts in Hood Canal, Washington State

    PubMed Central

    Moore, Megan; Berejikian, Barry A.; Tezak, Eugene P.

    2013-01-01

    Background Habitat modifications resulting from human transportation and power-generation infrastructure (e.g., roads, dams, bridges) can impede movement and alter natural migration patterns of aquatic animal populations, which may negatively affect survival and population viability. Full or partial barriers are especially problematic for migratory species whose life histories hinge on habitat connectivity. Methodology/Principal Findings The Hood Canal Bridge, a floating structure spanning the northern outlet of Hood Canal in Puget Sound, Washington, extends 3.6 meters underwater and forms a partial barrier for steelhead migrating from Hood Canal to the Pacific Ocean. We used acoustic telemetry to monitor migration behavior and mortality of steelhead smolts passing four receiver arrays and several single receivers within the Hood Canal, Puget Sound, and Strait of Juan de Fuca. Twenty-seven mortality events were detected within the vicinity of the Hood Canal Bridge, while only one mortality was recorded on the other 325 receivers deployed throughout the study area. Migrating steelhead smolts were detected at the Hood Canal Bridge array with greater frequency, on more receivers, and for longer durations than smolts migrating past three comparably configured arrays. Longer migration times and paths are likely to result in a higher density of smolts near the bridge in relation to other sites along the migration route, possibly inducing an aggregative predator response to steelhead smolts. Conclusions/Significance This study provides strong evidence of substantial migration interference and increased mortality risk associated with the Hood Canal Bridge, and may partially explain low early marine survival rates observed in Hood Canal steelhead populations. Understanding where habitat modifications indirectly increase predation pressures on threatened populations helps inform potential approaches to mitigation. PMID:24039937

  18. A floating bridge disrupts seaward migration and increases mortality of steelhead smolts in Hood Canal, Washington state.

    PubMed

    Moore, Megan; Berejikian, Barry A; Tezak, Eugene P

    2013-01-01

    Habitat modifications resulting from human transportation and power-generation infrastructure (e.g., roads, dams, bridges) can impede movement and alter natural migration patterns of aquatic animal populations, which may negatively affect survival and population viability. Full or partial barriers are especially problematic for migratory species whose life histories hinge on habitat connectivity. The Hood Canal Bridge, a floating structure spanning the northern outlet of Hood Canal in Puget Sound, Washington, extends 3.6 meters underwater and forms a partial barrier for steelhead migrating from Hood Canal to the Pacific Ocean. We used acoustic telemetry to monitor migration behavior and mortality of steelhead smolts passing four receiver arrays and several single receivers within the Hood Canal, Puget Sound, and Strait of Juan de Fuca. Twenty-seven mortality events were detected within the vicinity of the Hood Canal Bridge, while only one mortality was recorded on the other 325 receivers deployed throughout the study area. Migrating steelhead smolts were detected at the Hood Canal Bridge array with greater frequency, on more receivers, and for longer durations than smolts migrating past three comparably configured arrays. Longer migration times and paths are likely to result in a higher density of smolts near the bridge in relation to other sites along the migration route, possibly inducing an aggregative predator response to steelhead smolts. This study provides strong evidence of substantial migration interference and increased mortality risk associated with the Hood Canal Bridge, and may partially explain low early marine survival rates observed in Hood Canal steelhead populations. Understanding where habitat modifications indirectly increase predation pressures on threatened populations helps inform potential approaches to mitigation.

  19. Massage Efficacy Beliefs for Muscle Recovery from a Running Race

    PubMed Central

    Moraska, Albert

    2013-01-01

    Background Belief in efficacy of CAM therapies has been sparsely reported and may be different than reported use of the therapy. Purpose The aim of this study was to identify efficacy beliefs of massage for muscle recovery following a 10-km running race. Setting Finish zone of a 10-km race. Research Design Participants completed a brief survey regarding running race characteristics, prior use of massage, and belief in efficacy of massage regarding muscle recovery from the race. Participants The subject pool consisted of 745 individuals who completed a running race and were within 60 minutes of race completion. Main Outcome Measures Subjects reported demographic information (age, gender), race information (finish time, perceived exertion, muscle soreness, fatigue), prior use of massage, and belief regarding efficacy of massage for postrace muscle recovery. Results Most study participants believed that massage would benefit muscle recovery following the running race (80.0%), even though only 43.9% had received a massage previously. Those who had received at least one massage were significantly more likely to believe that massage would benefit muscle recovery (91.9% vs. 70.4%, p < .001). Females were more likely than males to have had a massage (52.3% vs. 36.0%, p < .001) and to believe it would benefit recovery (83.1% vs. 77.1%, p = .046). Conclusions Massage is well-accepted as a muscle recovery aid following a running race, but females and those who have used massage were significantly more likely to perceive it as advantageous. Belief in a therapeutic value of massage for muscle recovery exceeds its reported use. PMID:23730395

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

    USGS Publications Warehouse

    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.

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

    USGS Publications Warehouse

    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.

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

    USGS Publications Warehouse

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

    2007-01-01

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

  3. Critical swimming speeds of wild bull trout

    USGS Publications Warehouse

    Mesa, M.G.; Weiland, L.K.; Zydlewski, G.B.

    2004-01-01

    We estimated the critical swimming speeds (Ucrit) of wild bull trout at 6??, 11??, and 15??C in laboratory experiments. At 11??C, 5 fish ranging from 11 to 19 cm in length had a mean Ucrit of 48.24 cm/s or 3.22 body lengths per second (BL/s). Also at 11??C , 6 fish from 32 to 42 cm had a mean Ucrit of 73.99 cm/s or 2.05 BL/s. At 15??C, 5 fish from 14 to 23 cm had a mean Ucrit of 54.66 cm/s or 2.88 BL/s. No fish successfully swam at 6??C. Swim speed was significantly influenced by fish length. Many bull trout performed poorly in our enclosed respirometers: of 71 Ucrit tests we attempted, only the 16 described above were successful. Bull trout that refused to swim held station within tunnels by using their pectoral fins as depressors, or they rested and later became impinged against a downstream screen. Several common techniques did not stimulate consistent swimming activity in these fish. Our estimates of U crit for bull trout provide an understanding of their performance capacity and will be useful in modeling efforts aimed at improving fish passage structures. We recommend that fishway or culvert designers concerned with bull trout passage maintain velocities within their structures at or below our estimates of Ucrit, thus taking a conservative approach to ensuring that these fish can ascend migratory obstacles safely.

  4. The trout fishery in Shenandoah National Park

    USGS Publications Warehouse

    Lennon, Robert E.

    1961-01-01

    Populations of brook trout in streams of Shenandoah National Park were reduced drastically early in the past decade by a succession of unusually severe droughts and floods. The drying of stream beds, predation, and scouring were principal factors in the loss of fish. The park was closed to fishing in 1954 and 1955 to protect survivors. The small numbers of survivors quickly repopulated the streams after drought conditions abated. The stocking of hatchery-reared fingerling trout in selected waters failed to augment the recovery of populations. Survival and growth of young, wild trout were especially good. Their redistribution through miles of previously dry streams was rapid. The park was opened again to fishing in 1956 under regulations which restrict the take but afford an increase in sporting opportunity. Two streams were placed under fishing-for-fun-only regulations in 1961.The welfare of the trout populations is dependent mostly on the weather cycle . Fish may be abundant in wet years but very scarc e in dry ones. Thus, the stream must be managed a s marginal for trout.

  5. RNA-seq reveals differential gene expression in the brains of juvenile resident and migratory smolt rainbow trout (Oncorhynchus mykiss).

    PubMed

    Hale, Matthew C; McKinney, Garrett J; Thrower, Frank P; Nichols, Krista M

    2016-12-01

    Many migratory traits are heritable, but there is a paucity of evidence identifying the molecular mechanisms underlying differentiation in alternative migratory tactics, or in linking variation in gene expression to migratory behaviors. To that end, we examined differential gene expression in the brain transcriptome between young steelhead trout that had undergone the smoltification process, and resident rainbow trout (Oncorhynchus mykiss) from Sashin Creek, Alaska. Samples were sequenced from two time points: immediately before (at 20months of age) and during (2years of age) the presumed peak of smoltification. Smolt and resident individuals came from two genetic crosses, one where both parents were migratory, and another where both parents were residents. A total of 533 (1.9%) genes were differentially expressed between crosses, or between smolt and resident samples. These genes include some candidate migratory genes (such as POMC), as well as genes with no previous known involvement in the migratory process. Progeny from resident parents showed more upregulated genes than progeny from migrant parents at both time points. Pathway analysis showed enrichment in 227 biological pathways between cross type, and 171 biological pathways were enriched between residents and smolts. Enriched pathways had connections to many biofunctions, and most were only enriched in one contrast. However, pathways connected to phototransduction were enriched between both cross type and migratory tactics in 11 out of 12 contrasts, suggesting there are fundamental differences in how smolts and residents process light in the brain. The genes and pathways described herein constitute an a priori candidate list for future studies of migration in other populations of O. mykiss, and other migratory species. Published by Elsevier Inc.

  6. Innocent until proven guilty? Stable coexistence of alien rainbow trout and native marble trout in a Slovenian stream

    NASA Astrophysics Data System (ADS)

    Vincenzi, Simone; Crivelli, Alain J.; Jesensek, Dusan; Rossi, Gianluigi; de Leo, Giulio A.

    2011-01-01

    To understand the consequences of the invasion of the nonnative rainbow trout Oncorhynchus mykiss on the native marble trout Salmo marmoratus, we compared two distinct headwater sectors where marble trout occur in allopatry (MTa) or sympatry (MTs) with rainbow trout (RTs) in the Idrijca River (Slovenia). Using data from field surveys from 2002 to 2009, with biannual (June and September) sampling and tagging from June 2004 onwards, we analyzed body growth and survival probabilities of marble trout in each stream sector. Density of age-0 in September over the study period was greater for MTs than MTa and very similar between MTs and RTs, while density of trout ≥age-1 was similar for MTa and MTs and greater than density of RTs. Monthly apparent survival probabilities were slightly higher in MTa than in MTs, while RTs showed a lower survival than MTs. Mean weight of marble and rainbow trout aged 0+ in September was negatively related to cohort density for both marble and rainbow trout, but the relationship was not significantly different between MTs and MTa. No clear depression of body growth of sympatric marble trout between sampling intervals was observed. Despite a later emergence, mean weight of RTs cohorts at age 0+ in September was significantly higher than weight of both MTs and MTa. The establishment of a self-sustaining population of rainbow trout does not have a significant impact on body growth and survival probabilities of sympatric marble trout. The numerical dominance of rainbow trout in streams at lower altitudes seem to suggest that while the low summer flow pattern of Slovenian streams is favorable for rainbow trout invasion, the adaptation of marble trout to headwater environments may limit the invasion success of rainbow trout in headwaters.

  7. Fate of Tetracapsuloides bryosalmonae (Myxozoa) after infection of brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss

    PubMed Central

    Kumar, Gokhlesh; Abd-Elfattah, Ahmed; Saleh, Mona; El-Matbouli, Mansour

    2014-01-01

    Tetracapsuloides bryosalmonae (Myxozoa) is the causative agent of proliferative kidney disease in salmonids. We assessed differences in intensity of T. bryosalmonae infection between brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss from the clinical phase of infection onwards. Specific pathogen-free fish were exposed to T. bryosalmonae spores under controlled laboratory conditions and sampled at 6, 8, 10, 12, 14, and 17 wk post exposure (wpe), and the transmission of T. bryosalmonae from infected fish to the bryozoan Fredericella sultana was observed. Parasite load was determined in fish kidneys by quantitative real-time PCR (qRT-PCR), and parasite stages were detected in kidney, liver, and spleen tissues at different time points by immunohistochemistry. T. bryosalmonae was successfully transmitted from infected brown trout to F. sultana colonies but not from infected rainbow trout. Body length and weight of infected brown trout did not differ significantly from control brown trout during all time points, while length and weight of infected rainbow trout differed significantly compared to controls from 10 to 17 wpe. qRT-PCR revealed that parasite load was significantly higher in kidneys of brown trout compared with rainbow trout. Immunohistochemistry showed high numbers of intra-luminal stages (sporogonic stages) in kidneys of brown trout with low numbers of pre-sporogonic stages. Sporogonic stages were not seen in kidneys of rainbow trout; only high numbers of pre-sporogonic stages were detected. Numbers of pre-sporogonic stages were low in the spleen and liver of brown trout but high in rainbow trout. These data confirmed that there are differences in the development and infection progress of T. bryosalmonae between brown trout and rainbow trout. PMID:24270019

  8. Spatial patterns in PCB concentrations of Lake Michigan lake trout

    USGS Publications Warehouse

    Madenjian, Charles P.; DeSorcie, Timothy J.; Stedman, Ralph M.; Brown, Edward H.; Eck, Gary W.; Schmidt, Larry J.; Hesselberg, Robert J.; Chernyak, Sergei M.; Passino-Reader, Dora R.

    1999-01-01

    Most of the PCB body burden in lake trout (Salvelinus namaycush) of the Great Lakes is from their food. PCB concentrations were determined in lake trout from three different locations in Lake Michigan during 1994–1995, and lake trout diets were analyzed at all three locations. The PCB concentrations were also determined in alewife (Alosa pseudoharengus), rainbow smelt (Osmerus mordax), bloater (Coregonus hoyi), slimy sculpin (Cottus cognatus), and deepwater sculpin (Myoxocephalus thompsoni), five species of prey fish eaten by lake trout in Lake Michigan, at three nearshore sites in the lake. Despite the lack of significant differences in the PCB concentrations of alewife, rainbow smelt, bloater, slimy sculpin, and deepwater sculpin from the southeastern nearshore site near Saugatuck (Michigan) compared with the corresponding PCB concentrations from the northwestern nearshore site near Sturgeon Bay (Wisconsin), PCB concentrations in lake trout at Saugatuck were significantly higher than those at Sturgeon Bay. The difference in the lake trout PCB concentrations between Saugatuck and Sturgeon Bay could be explained by diet differences. The diet of lake trout at Saugatuck was more concentrated in PCBs than the diet of Sturgeon Bay lake trout, and therefore lake trout at Saugatuck were more contaminated in PCBs than Sturgeon Bay lake trout. These findings were useful in interpreting the long-term monitoring series for contaminants in lake trout at both Saugatuck and the Wisconsin side of the lake.

  9. A comparison of the survival and migratory behavior of hatchery-reared and naturally reared steelhead smolts in the Alsea river and estuary, Oregon, using acoustic telemetry

    EPA Science Inventory

    We tracked three groups of steelhead Oncorhynchus mykiss smolts implanted with acoustic transmitters to determine whether the degree of hatchery domestication or the juvenile rearing environment (hatchery raceway versus natural stream) influenced migration timing and survival in ...

  10. Emigration of Natural and Hatchery Chinook Salmon and Steelhead Smolts from the Imnaha River, Oregon, Progress Report 2000-2002.

    SciTech Connect

    Cleary, Peter; Kucera, Paul; Blenden, Michael

    2003-12-01

    This report summarizes the emigration studies of the Nez Perce Tribe in the Imnaha River subbasin during the 2001 and 2002 migration years. A migration year for the Imnaha River is defined here as beginning July 31 of the previous year and ending July 30 the following year. The conclusion of the studies at the end of migration year 2002 marked the 11th year of the Nez Perce Tribe's Lower Snake River Emigration Studies. The Nez Perce Tribe has participated in the Fish Passage Center's Smolt Monitoring Program for nine of the 11 years. These studies collect and tag juvenilemore » chinook salmon and steelhead at two locations in the fall, rkm 74 and rkm 7, and at rkm 7 during the spring. Data from captured and tagged fish provide an evaluation of hatchery production and releases strategies, post release survival of hatchery chinook salmon, abundance of natural chinook salmon, and downstream survival and arrival timing of natural and hatchery chinook salmon and steelhead. The hydrologic conditions that migrating fish encountered in 2001 were characterized as a drought and conditions in 2002 were characterized as below average. Hatchery chinook salmon had a mean fork length that was 34 mm greater in 2001 and 35 mm greater in 2002 than the mean fork length of natural chinook smolts. Hatchery steelhead smolt mean fork lengths were 39 mm greater than natural steelhead smolts in 2001 and 44 mm greater than natural steelhead smolt fork lengths in 2002. A significant difference (p < 0.05) between hatchery and natural chinook salmon and steelhead fork lengths has been documented by these emigration studies from 1997 to 2002. Hatchery chinook salmon were volitionally released in 2001 and 2002 and the 90% arrivals for 2001 and 2002 at the lower rkm 7 trap were within the range of past observations of 22 to 38 days observed in 1999 and 2000. We estimated that 93.9% of the 123,014 hatchery chinook salmon released in 2001 survived to the lower trap and 90.2% of the 303

  11. Biotic and abiotic influences on abundance and distribution of nonnative Chinook salmon and native ESA-listed steelhead in the Wind River, Washington

    USGS Publications Warehouse

    Jezorek, Ian G.; Connolly, Patrick J.

    2015-01-01

    Biotic and abiotic factors influence fish populations and distributions. Concerns have been raised about the influence of hatchery fish on wild populations. Carson National Fish Hatchery produces spring Chinook salmon Oncorhynchus tshawytscha in the Wind River, Washington, and some spawn in the river. Managers were concerned that Chinook salmon could negatively affect wild steelhead O. mykiss and that a self-sustaining population of Chinook salmon may develop. Our objectives were to assess: 1) the distribution and populations of juvenile spring Chinook salmon and juvenile steelhead in the upper Wind River; 2) the influence of stream flow and of each population on the other; and 3) if Chinook salmon populations were self-sustaining. We snorkeled to determine distribution and abundance. Flow in the fall influenced upstream distribution and abundance of juvenile Chinook salmon. Juvenile Chinook salmon densities were consistently low (range 0.0 to 5.7 fish 100 m-2) and not influenced by number of spawners, winter flow magnitude, or steelhead abundance. Juvenile steelhead were distributed through the study section each year. Age-0 and age-1 steelhead densities (age-0 range: 0.04 to 37.0 fish 100 m-2; age-1 range: 0.02 to 6.21 fish 100 m-2) were consistently higher than for juvenile Chinook salmon. Steelhead spawner abundance positively influenced juvenile steelhead abundance. During this study, Chinook salmon in the Wind River appear to have had little effect on steelhead. Low juvenile Chinook salmon abundance and a lack of a spawner-to-juvenile relationship suggest Chinook salmon are not self-sustaining and potential for such a population is low under current conditions.

  12. Microsatellite analyses of the trout of northwest Mexico

    USGS Publications Warehouse

    Nielsen, J.L.; Sage, G.K.

    2001-01-01

    The trout of northwest Mexico represent an undescribed group of fish considered part of the Oncorhynchus mykiss (Pacific trout) complex of species and subspecies. Recent genetic studies have shown these fish to have important genetic diversity and a unique evolutionary history when compared to coastal rainbow trout. Increased levels of allelic diversity have been found in this species at the southern extent of its range. In this study we describe the trout in the Sierra Madre Occidental from the rios Yaqui, Mayo, Casas Grandes and de Bavispe, and their relationship to the more southern distribution of Mexican golden trout (O. chrysogaster) using 11 microsatellite loci. Microsatellite allelic diversity in Mexican trout was high with a mean of 6.6 alleles/locus, average heterozygosity = 0.35, and a mean Fst = 0.43 for all loci combined. Microsatellite data were congruent with previously published mtDNA results showing unique panmictic population structure in the Rio Yaqui trout that differs from Pacific coastal trout and Mexican golden trout. These data also add support for the theory of headwaters transfer of trout across the Continental Divide from tributaries of the Rio de Bavispe into the Rio Casas Grandes. Rio Mayo trout share a close genetic relationship to trout in Rio Yaqui, but sample sizes from the Rio Mayo prevent significant comparisons in this study. Microsatellite analyses show significant allelic frequency differences between Rio Yaqui trout and O. chrysogaster in Sinaloa and Durango Mexico, adding further support for a unique evolutionary status for this group of northwestern Mexican trout.

  13. Laboratory evaluation of a lake trout bioenergetics model

    USGS Publications Warehouse

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

    1999-01-01

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

  14. Genetic variation in steelhead (Salmo gairdneri) from the north coast of Washington

    USGS Publications Warehouse

    Reisenbichler, R.R.; Phelps, S.R.

    1989-01-01

    Steelhead (Salmo gairdneri) collected from various sites in nine drainages in northwestern Washington were genetically characterized at 65 protein-coding loci by starch-gel electrophoresis. Genetic differentiation within and among drainages was not significant, and genetic variation among drainages was much less than that reported in British Columbia; these results may be the consequence of gene flow from hatchery stocks that have been released in Washington since the 1940's. Allele frequencies varied significantly among year-classes (hence, genetic characterization studies must include data from several year-classes), and also between hatchery fish (including a stock developed with local wild fish) and wild fish, indicating that few wild fish have been successfully and routinely included in hatchery brood stocks. Conservation of genetic diversity along the north coast of Washington should be facilitated by reducing the numbers of hatchery fish that spawn in streams and by including wild fish in hatchery brood stocks.

  15. A non-lethal measure of smolt status of juvenile steelhead based on body morphology

    USGS Publications Warehouse

    Beeman, John W.; Rondorf, D.W.; Tilson, M.E.; Venditti, D.A.

    1995-01-01

    A nonlethal morphometric method to assess smolt status of juvenile steelhead Oncorhynchus mykiss was validated. Fish were collected from hatcheries before release and during their seaward migration in a large river system. Fifteen anatomical landmarks were digitized from photographs of each fish, resulting in 34 morphometric characters based on a truss network. Principal component and canonical discriminant function analyses were used to assess smolt status. A single canonical variate was significantly correlated with gill Na+,K+-ATPase activity, a commonly used measure of smolt status. This nonlethal method may be a useful measure of smolt status when sacrificing fish is not desirable or possible; it requires little training to perform, but it does require a larger sample size than some other methods.

  16. Natural selection after release from a hatchery leads to domestication in steelhead, Oncorhynchus mykiss

    USGS Publications Warehouse

    Leber, K.M.; Kitada, S.; Blankenship, H.L.; Svåsand, T.

    2004-01-01

    Genetic theory and data suggest that sea ranching of anadromous salmonids (Oncorhynchus spp. and Salmo spp.) results in domestication (increased fitness in the hatchery program) accompanied by a loss of fitness for natural production. We tested for genetic differences in growth, survival, and downstream migration of hatchery and wild steelhead (O. mykiss) reared together in a hatchery. We found little or no difference in survival during hatchery rearing but substantial differences in growth and subsequent downstream migration. Intense natural selection after release from the hatchery favored fish that had performed well (e.g. grew fast) in the hatchery. This selection in the natural environment genetically changes (domesticates) the population because at least some of the performance traits are heritable. Domestication should improve the economic efficiency for producing adult hatchery fish but compromise conservation of wild populations when hatchery fish interbreed with wild fish.

  17. Restricted gene flow between resident Oncorhynchus mykiss and an admixed population of anadromous steelhead

    USGS Publications Warehouse

    Matala, Andrew P.; Allen, Brady; Narum, Shawn R.; Harvey, Elaine

    2017-01-01

    The species Oncorhynchus mykiss is characterized by a complex life history that presents a significant challenge for population monitoring and conservation management. Many factors contribute to genetic variation in O. mykiss populations, including sympatry among migratory phenotypes, habitat heterogeneity, hatchery introgression, and immigration (stray) rates. The relative influences of these and other factors are contingent on characteristics of the local environment. The Rock Creek subbasin in the middle Columbia River has no history of hatchery supplementation and no dams or artificial barriers. Limited intervention and minimal management have led to a dearth of information regarding the genetic distinctiveness of the extant O. mykiss population in Rock Creek and its tributaries. We used 192 SNP markers and collections sampled over a 5‐year period to evaluate the temporal and spatial genetic structures of O. mykissbetween upper and lower watersheds of the Rock Creek subbasin. We investigated potential limits to gene flow within the lower watershed where the stream is fragmented by seasonally dry stretches of streambed, and between upper and lower watershed regions. We found minor genetic differentiation within the lower watershed occupied by anadromous steelhead (FST = 0.004), and evidence that immigrant influences were prevalent and ubiquitous. Populations in the upper watershed above partial natural barriers were highly distinct (FST = 0.093) and minimally impacted by apparent introgression. Genetic structure between watersheds paralleled differences in local demographics (e.g., variation in size), migratory restrictions, and habitat discontinuity. The evidence of restricted gene flow between putative remnant resident populations in the upper watershed and the admixed anadromous population in the lower watershed has implications for local steelhead productivity and regional conservation.

  18. Lake trout in northern Lake Huron spawn on submerged drumlins

    USGS Publications Warehouse

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

    2014-01-01

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

  19. Role of stream ice on fall and winter movements and habitat use by bull trout and cutthroat trout in Montana headwater streams

    Treesearch

    Michael J. Jakober; Thomas E. McMahon; Russell F. Thurow; Christopher G. Clancy

    1998-01-01

    We used radiotelemetry and underwater observation to assess fall and winter movements and habitat use by bull trout Salvelinus confluentus and westslope cutthroat trout Oncorhynchus clarki lewisi in two headwater streams in the Bitterroot River drainage, Montana, that varied markedly in habitat availability and stream ice conditions. Bull trout and cutthroat trout made...

  20. Conservation assessment for inland cutthroat trout

    Treesearch

    Michael K. Young

    1995-01-01

    This document focuses on the state of the science for five subspecies of cutthroat trout found largely on public lands in the Rocky Mountain and Intermountain West. These subspecies are restricted to a fragment of their former range, and primarily occupy small, high-elevation streams. Little is known about the three rarest subspecies (Bonneville, Colorado River, and...

  1. Brook Trout Back in Aaron Run

    EPA Pesticide Factsheets

    Following a series of acid mine drainage (AMD) projects funded largely by EPA’s Clean Water Act Section 319 non-point source program, the pH level in Aaron Run is meeting Maryland’s water quality standard – and the brook trout are back.

  2. Development of bull trout sampling protocols

    Treesearch

    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...

  3. Protocol for determining bull trout presence

    Treesearch

    James Peterson; Jason B. Dunham; Philip Howell; Russell Thurow; Scott Bonar

    2002-01-01

    The Western Division of the American Fisheries Society was requested to develop protocols for determining presence/absence and potential habitat suitability for bull trout. The general approach adopted is similar to the process for the marbled murrelet, whereby interim guidelines are initially used, and the protocols are subsequently refined as data are collected....

  4. Chapter 3. Rio Grande cutthroat trout

    Treesearch

    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...

  5. Chapter 2. Colorado River cutthroat trout

    Treesearch

    Michael K. Young

    1995-01-01

    The Colorado River cutthroat trout historically occupied portions of the Colorado River drainage in Wyoming, Colorado, Utah, Arizona, and New Mexico (Behnke 1992). Though it is now restricted to headwater streams and lakes, its original distribution probably included portions of larger streams, such as the Green (Simon 1935), Yampa, White, Colorado, and San Juan rivers...

  6. Genetic differences in growth, migration, and survival between hatchery and wild steelhead and Chinook salmon: Introduction and executive summary

    USGS Publications Warehouse

    Rubin, Steve P.; Reisenbichler, Reginald; Wetzel, Lisa A.; Hayes, Michael C.

    2012-01-01

    This report presents results of studies testing for genetically based differences in performance (growth, migration, and survival) between hatchery and wild populations of steelhead and Chinook salmon (Project Number 90-052). The report is organized into 10 chapters with a general study introduction preceding the first chapter. A growing body of data shows that domestication and a resulting loss of fitness for natural rearing occur in hatchery populations of anadromous salmonids; however, the magnitude of domestication will vary among species and hatchery programs. Better information on domestication is needed to accurately predict the consequences when hatchery and wild fish interbreed. The intent of hatchery supplementation is to increase natural production through introduction of hatchery fish into natural production areas. The goal of this study was to provide managers with information on the genetic risks of hatchery supplementation to wild populations of Columbia River Basin summer steelhead and spring Chinook salmon.

  7. Escapement and Productivity of Spring Chinook and Summer Steelhead in the John Day River Basin, Technical Report 2004-2005.

    SciTech Connect

    Wilson, Wayne

    2007-04-01

    The objectives are: (1) Estimate number and distribution of spring Chinook salmon Oncorhynchus tshawytscha redds and spawners in the John Day River subbasin; and (2) Estimate smolt-to-adult survival rates (SAR) and out-migrant abundance for spring Chinook and summer steelhead O. mykiss and life history characteristics of summer steelhead. Spawning ground surveys for spring (stream-type) Chinook salmon were conducted in four main spawning areas (Mainstem, Middle Fork, North Fork, and Granite Creek System) and seven minor spawning areas (South Fork, Camas Creek, Desolation Creek, Trail Creek, Deardorff Creek, Clear Creek, and Big Creek) in the John Day River basin during Augustmore » and September of 2005. Census surveys included 298.2 river kilometers (88.2 rkm within index, 192.4 rkm additional within census, and 17.6 rkm within random survey areas) of spawning habitat. We observed 902 redds and 701 carcasses including 227 redds in the Mainstem, 178 redds in the Middle Fork, 420 redds in the North Fork, 62 redds in the Granite Creek System, and 15 redds in Desolation Creek. Age composition of carcasses sampled for the entire basin was 1.6% age 3, 91.2% age 4, and 7.1% age 5. The sex ratio was 57.4% female and 42.6% male. Significantly more females than males were observed in the Granite Creek System. During 2005, 82.3% of female carcasses sampled had released all of their eggs. Significantly more pre-spawn mortalities were observed in Granite Creek. Nine (1.3%) of 701 carcasses were of hatchery origin. Of 298 carcasses examined, 4.0% were positive for the presence of lesions. A significantly higher incidence of gill lesions was found in the Granite Creek System when compared to the rest of the basin. Of 114 kidney samples tested, two (1.8%) had clinical BKD levels. Both infected fish were age-4 females in the Middle Fork. All samples tested for IHNV were negative. To estimate spring Chinook and summer steelhead smolt-to-adult survival (SAR) we PIT tagged 5

  8. Determination of habitat requirements for Apache Trout

    USGS Publications Warehouse

    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.

  9. Lake trout rehabilitation in Lake Ontario

    USGS Publications Warehouse

    Elrod, Joseph H.; O'Gorman, Robert; Schneider, Clifford P.; Eckert, Thomas H.; Schaner, Ted; Bowlby, James N.; Schleen, Larry P.

    1995-01-01

    Attempts to maintain the native lake trout (Salvelinus namaycush) population in Lake Ontario by stocking fry failed and the species was extirpated by the 1950s. Hatchery fish stocked in the 1960s did not live to maturity because of sea lamprey (Petromyzon marinus) predation and incidental commercial harvest. Suppression of sea lampreys began with larvicide treatments of Lake Ontario tributaries in 1971 and was enhanced when the tributaries of Oneida Lake and Lake Erie were treated in the 1980s. Annual stocking of hatchery fish was resumed with the 1972 year class and peaked at about 1.8 million yearlings and 0.3 million fingerlings from the 1985–1990 year classes. Survival of stocked yearlings declined over 50% in the 1980 s and was negatively correlated with the abundance of lake trout > 550 mm long (r = −0.91, P < 0.01, n = 12). A slot length limit imposed by the State of New York for the 1988 fishing season reduced angler harvest. Angler harvest in Canadian waters was 3 times higher in eastern Lake Ontario than in western Lake Ontario. For the 1977–1984 year classes, mean annual survival rate of lake trout age 6 and older was 0.45 (range: 0.35–0.56). In U.S. waters during 1985–1992, the total number of lake trout harvested by anglers was about 2.4 times greater than that killed by sea lampreys. The number of unmarked lake trout < 250 mm long in trawl catches in 1978–1992 was not different from that expected due to loss of marks and failure to apply marks at the hatchery, and suggested that recruitment of naturally-produced fish was nil. However, many of the obstacles which may have impeded lake trout rehabilitation in Lake Ontario during the 1980s are slowly being removed, and there are signs of a general ecosystem recovery. Significant recruitment of naturally produced lake trout by the year 2000, one interim objective of the rehabilitation plan for the Lake, may be achieved.

  10. Embryotoxicity of Great Lakes lake trout extracts to developing rainbow trout

    USGS Publications Warehouse

    Wright, Peggy J.; Tillitt, Donald E.

    1999-01-01

    Planar halogenated hydrocarbons (PHHs), such as polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls are present in aquatic systems, and are known to produce adverse effects in fish. This study investigated the embryotoxicity of PHH mixtures through the nanoinjection of environmental extracts into newly fertilized eggs from two strains of rainbow trout. Organic extracts were obtained from whole adult lake trout collected from Lake Michigan in 1988 and Lake Superior in 1994. The graded doses of the final extracts used for injection were quantified as 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic-equivalents (TEQs) based on the concentrations of dioxins, furans and non-o-PCBs in each, and as equivalent amounts found in the eggs of the original lake trout (eggEQ). Total TEQs in the lake trout were 14.7 pg TEQ/g in the Lake Michigan sample and 7.3 pg TEQ/g in the Lake Superior sample. The extract of the Lake Michigan lake trout was embryotoxic to rainbow trout; LD50 values were 35 eggEQ (15–90, 95% F.L.) in the Arlee strain and 14 eggEQ (5–99, 95% F.L.) in the Erwin strain of rainbow trout. The LD50 values of the Lake Michigan extract in either of these strains of rainbow trout fall within the actual range of TCDD LD50values based on TEQs. This indicates that an additive model of toxicity is appropriate to quantify PHHs in relation to early life stage mortality in fish. Gross lesions characteristic of exposure to PHHs (i.e. yolk-sac edema, craniofacial deformities, and hemorrhaging) increased in a dose-related manner. The lowest observable adverse effect concentrations (LOAEC) for these gross lesions and cumulative mortalities suggests that current concentrations of PHHs in lake trout from Lake Michigan are above a threshold for adverse effects and these compounds may have implications on the lack of recruitment in certain Great Lakes lake trout populations.

  11. Infectious pancreatic necrosis the trout farmers' dilemma

    USGS Publications Warehouse

    Parisot, T.J.

    1965-01-01

    Induction of the innate immune pathways is critical for early anti-viral defense but there is limited understanding of how teleost fish recognize viral molecules and activate these pathways. In mammals, Toll-like receptors (TLR) 7 and 8 bind single-stranded RNA of viral origin and are activated by synthetic anti-viral imidazoquinoline compounds. Herein, we identify and describe the rainbow trout (Oncorhynchus mykiss) TLR7 and TLR8 gene orthologs and their mRNA expression. Two TLR7/8 loci were identified from a rainbow trout bacterial artificial chromosome (BAC) library using DNA fingerprinting and genetic linkage analyses. Direct sequencing of two representative BACs revealed intact omTLR7and omTLR8a1 open reading frames (ORFs) located on chromosome 3 and a second locus on chromosome 22 that contains an omTLR8a2 ORF and a putative TLR7pseudogene. We used the omTLR8a1/2 nomenclature for the two trout TLR8 genes as phylogenetic analysis revealed that they and all the other teleost TLR8 genes sequenced to date are similar to the zebrafish TLR8a, but are distinct from the zebrafish TLR8b. The duplicated trout loci exhibit conserved synteny with other fish genomes extending beyond the tandem of TLR7/8 genes. The trout TLR7 and 8a1/2 genes are composed of a single large exon similar to all other described TLR7/8 genes. The omTLR7 ORF is predicted to encode a 1049 amino acid (aa) protein with 84% similarity to the Fugu TLR7and a conserved pattern of predicted leucine-rich repeats (LRR). The omTLR8a1 andomTLR8a2 are predicted to encode 1035- and 1034-aa proteins, respectively, and have 86% similarity to each other. omTLR8a1 is likely the ortholog of the only Atlantic salmonTLR8 gene described to date as they have 95% aa sequence similarity. The tissue expression profiles of omTLR7, omTLR8a1 and omTLR8a2 in healthy trout were highest in spleen tissue followed by anterior and then posterior kidney tissues. Rainbow trout anterior kidney leukocytes produced elevated levels of

  12. Who's your momma? Recognizing maternal origin of juvenile steelhead using injections of strontium chloride to create transgenerational marks

    USGS Publications Warehouse

    Shippentower, Gene E.; Schreck, Carl B.; Heppell, Scott A.

    2011-01-01

    We sought to determine whether a strontium chloride injection could be used to create a transgenerational otolith mark in steelhead Oncorhynchus mykiss. Two strontium injection trials and a survey of strontium: calcium (Sr:Ca) ratios in juvenile steelhead from various steelhead hatcheries were conducted to test the feasibility of the technique. In both trials, progeny of fish injected with strontium had significantly higher Sr:Ca ratios in the primordial region of their otoliths, as measured by an electron wavelength dispersive microprobe. In trial 1, the 5,000-mg/L treatment level showed that 56.8% of the otoliths were correctly classified, 12.2% being misclassified as belonging to the 0-mg/L treatment. In trial 2, the 20,000-mg/L treatment level showed that 30.8% of the otoliths were correctly classified, 13.5% being misclassified as belonging to the 0-mg/L treatment. There were no differences in the fertilization rates of eggs or survival rates of fry between the treatment and control groups. The Sr:Ca ratios in otoliths collected from various hatchery populations of steelhead varied and were greater than those found in otoliths from control fish in both of our injection trials. This study suggests that the marking technique led to recognizable increases in Sr:Ca ratios in some otoliths collected from fry produced by injected females. Not all progeny showed such increases, however, suggesting that the method holds promise but requires further refinement to reduce variation. Overall, there was a correct classification of about 40% across all treatments and trials; the variation in Sr:Ca ratios found among experimental trials and hatcheries indicates that care must be taken if the technique is employed where fish from more than one hatchery could be involved.

  13. The Effect of Hatchery Release Strategy on Marine Migratory Behaviour and Apparent Survival of Seymour River Steelhead Smolts (Oncorhynchus mykiss)

    PubMed Central

    Balfry, Shannon; Welch, David W.; Atkinson, Jody; Lill, Al; Vincent, Stephen

    2011-01-01

    Early marine migratory behaviour and apparent survival of hatchery-reared Seymour River steelhead (Oncorhynchus mykiss) smolts was examined over a four year period (2006–2009) to assess the impact of various management strategies on improving early marine survival. Acoustically tagged smolts were released to measure their survival using estuary and coastal marine receivers forming components of the Pacific Ocean Shelf Tracking (POST) array. Early marine survival was statistically indistinguishable between releases of summer run and winter run steelhead races, night and day releases, and groups released 10 days apart. In 2009, the survival of summer run steelhead released into the river was again trialed against groups released directly into the ocean at a distance from the river mouth. Apparent survival was improved significantly for the ocean released groups. The health and physiological status of the various release groups were monitored in years 2007–2009, and results indicate that the fish were in good health, with no clinical signs of disease at the time of release. The possibility of a disease event contributing to early marine mortality was further examined in 2009 by vaccinating half of the released fish against common fish diseases (vibriosis, furunculosis). The results suggest that marine survival may be enhanced using this approach, although not to the extent observed when the smolts were transported away from the river mouth before release. In summary, direct experimental testing of different release strategies using the POST array to measure ocean survival accelerated the scientific process by allowing rapid collection of data which enabled the rejection of several existing theories and allowed tentative identification of several new alternative approaches that might improve early marine survival of Seymour River steelhead. PMID:21468320

  14. Factors affecting route selection and survival of steelhead kelts at Snake River dams in 2012 and 2013

    SciTech Connect

    Harnish, Ryan A.; Colotelo, Alison H. A.; Li, Xinya

    2015-03-31

    In 2012 and 2013, Pacific Northwest National Laboratory (PNNL) conducted a study that summarized the passage route proportions and route-specific survival rates of steelhead kelts that passed through Federal Columbia River Power System (FCRPS) dams. To accomplish this, a total of 811 steelhead kelts were tagged with Juvenile Salmon Acoustic Telemetry System (JSATS) transmitters. Acoustic receivers, both autonomous and cabled, were deployed throughout the FCRPS to monitor the downstream movements of tagged kelts. Kelts were also tagged with passive integrated transponder tags to monitor passage through juvenile bypass systems (JBS) and detect returning fish. The current study evaluated data collectedmore » in 2012 and 2013 to identify environmental, temporal, operational, individual, and behavioral variables that were related to forebay residence time, route of passage, and survival of steelhead kelts at FCRPS dams on the Snake River. Multiple approaches, including 3-D tracking, bivariate and multivariable regression modeling, and decision tree analyses were used to identify the environmental, temporal, operational, individual, and behavioral variables that had the greatest effect on forebay residence time, route of passage, and route-specific and overall dam passage survival probabilities for tagged kelts at Lower Granite (LGR), Little Goose (LGS), and Lower Monumental (LMN) dams. In general, kelt behavior and discharge appeared to work independently to affect forebay residence times. Kelt behavior, primarily approach location, migration depth, and “searching” activities in the forebay, was found to have the greatest influence on their route of passage. The condition of kelts was the single most important factor affecting their survival. The information gathered in this study may be used by dam operators and fisheries managers to identify potential management actions to improve in-river survival of kelts or collection methods for kelt reconditioning programs

  15. Survival and Passage of Yearling and Subyearling Chinook Salmon and Juvenile Steelhead at McNary Dam, 2012

    SciTech Connect

    Hughes, James S.; Weiland, Mark A.; Woodley, Christa M.

    2013-12-23

    The study was designed to evaluate the passage and survival of yearling and subyearling Chinook salmon and juvenile steelhead at McNary Dam as stipulated by the 2008 Biological Opinion and Fish Accords and to assess performance measures including route-specific fish passage proportions, travel times, and survival based upon a virtual/paired-release model. This study supports the USACE’s continual effort to improve conditions for juvenile anadromous fish passing through Columbia River dams.

  16. Compliance Monitoring of Juvenile Yearling Chinook Salmon and Steelhead Survival and Passage at the Dalles Dam, Spring 2010

    DTIC Science & Technology

    2010-10-01

    if applicable): Not applicable; this is a compliance study Fish: Implant Procedure: Species-race: yearling Chinook salmon (CH1), steelhead ( STH ...Surgical: Yes Injected: No Source: John Day Dam fish collection facility Size (median): CH1 STH Sample Size: CH1 STH Weight: 31.4 g 78.1 g...conditions and survival for downstream migrants. Survival and Passage Estimates (value & SE): CH1 STH Dam survival 0.9641 (SE = 0.0096) 0.9534

  17. Productivity of Spring Chinook Salmon and Summer Steelhead in the John Day River Basin, 2008 Annual Technical Report.

    SciTech Connect

    Wilson, Wayne H.; Schricker, Jaym'e; Ruzychi, James R.

    2009-02-13

    The John Day River subbasin supports one of the last remaining intact wild populations of spring Chinook salmon and summer steelhead in the Columbia River Basin. These populations remain depressed relative to historic levels and limited information is available for steelhead life history. Numerous habitat protection and rehabilitation projects have been implemented in the basin to improve salmonid freshwater production and survival. However, these projects often lack effectiveness monitoring. While our monitoring efforts outlined here will not specifically measure the effectiveness of any particular project, they will provide much needed programmatic or watershed (status and trend) information to help evaluatemore » project-specific effectiveness monitoring efforts as well as meet some data needs as index stocks. Our continued monitoring efforts to estimate salmonid smolt abundance, age structure, SAR, smolts/redd, freshwater habitat use, and distribution of critical life states will enable managers to assess the long-term effectiveness of habitat projects and to differentiate freshwater and ocean survival. Because Columbia Basin managers have identified the John Day subbasin spring Chinook population as an index population for assessing the effects of alternative future management actions on salmon stocks in the Columbia Basin (Schaller et al. 1999) we continue our ongoing studies. This project is high priority based on the level of emphasis by the NWPPC Fish and Wildlife Program, Independent Scientific Advisory Board (ISAB), Independent Scientific Review Panel (ISRP), NOAA National Marine Fisheries Service (NMFS), and the Oregon Plan for Salmon and Watersheds (OWEB). Each of these groups have placed priority on monitoring and evaluation to provide the real-time data to guide restoration and adaptive management in the region. The objective is to estimate smolt-to-adult survival rates (SAR) and out-migrant abundance for spring Chinook Oncorhynchus tshawytscha and

  18. Effect of dietary salt on migration and survival of yearling steelhead produced at Iron Gate Hatchery, Klamath River, 2009

    USGS Publications Warehouse

    Juhnke, S.; Hansel, H.; Wright,; Hetrick,

    2011-01-01

    We surgically implanted radio transmitters into 30 hatchery yearling steelhead (Oncorhynchus mykiss) released from Iron Gate Hatchery during the spring of 2009 to improve our understanding of the effect of dietary salt on their out-migration and survival. Steelhead yearlings were divided into two feed treatments to test the efficacy of a salt-enriched feed in promoting out-migration. Fish were fed either their regular diet (control treatment) or a salt-enriched diet (test treatment) for 38 d prior to their release. We implanted 15 fish of each treatment with radio transmitters for a total of 30 tagged individuals. Nine of the radio-tagged steelhead (four of the control treatment; five of the test treatment) completed their downstream migration to the estuary within the 60-d operational period of the tags. Tagged fish migrated from the hatchery release site to the estuary in an average of 45 d. Neither migration nor survival differed between diet treatments, but small sample size and the relatively short duration of this study limit the conclusiveness of our findings.

  19. Mink predation on brown trout in a Black Hills stream

    USGS Publications Warehouse

    Davis, Jacob L.; Wilhite, Jerry W.; Chipps, Steven R.

    2016-01-01

    In the early 2000’s, declines in the brown trout (Salmo trutta) fishery in Rapid Creek, South Dakota, caused concern for anglers and fisheries managers. We conducted a radio telemetry study in 2010 and 2011 to identify predation mortality associated with mink, using hatchery-reared (2010) or wild (2011) brown trout. Estimated predation rates by mink (Mustela vison) on radio-tagged brown trout were 30% for hatchery fish and 32% for wild fish. Size frequency analysis revealed that the size distribution of brown trout lost to predation was similar to that of other, radio-tagged brown trout. In both years, a higher proportion of predation mortality (83–92%) occurred during spring, consistent with seasonal fish consumption by mink. Predation by mink appeared to be a significant source of brown trout mortality in our study.

  20. Rainbow trout embryotoxicity of a complex contaminant mixture extracted from Lake Michigan lake trout

    USGS Publications Warehouse

    Wilson, P.J.; Tillitt, D.E.

    1996-01-01

    Persistent Hydrophobic contaminants such as poly chlorinated dibenzo-p-dioxins, dibenzofurans and biphenyl congeners are present in aquatic systems, and are known to produce adverse effects in fish. Reproductive failure in fish populations has been observed in aquatic systems contaminated with persistent hydrophobic compounds. In order to mimic maternal transfer of environmental contaminants to newly fertilized fish eggs, a complex environmental extract was tested for embryotoxicity in a nanoinjection bioassay with embryos of rainbow trout. The extract was obtained from whole adult lake trout collected from Lake Michigan in 1988. The tissue extraction involved blending and dehydration with sodium sulfate, column extraction, dialysis separation, reactive cleanup and, finally, high-performance gel permeation chromatography. Egg gram-equivalent doses (g tissue/g egg normalized for egg % lipid) of the final extract (0.02, 0.10, 0.20, 1.0, 2.0, 4.0, 10.0, 20.0 eggEQ) were injected into newly fertilized rainbow trout eggs using triolein as the vehicle. The extract of the lake trout was embryotoxic to rainbow trout, with an LD50 of 35 eggEQ, based on total cumulative mortality. Gross physical abnormalities characteristic of dioxin exposure, such as hemorrhaging, yolk-sac edema and craniofacial deformities, were observed and showed significant dose-related increases. Sublethal effects in the rainbow trout, such as delayed time to hatch, mild hemorrhaging and moderate yolk-sac edema, resulted from estimated total PCB exposure as low as 8.8 ng/g, and this may have significant implications on Great Lakes lake trout fry and juvenile mortality.

  1. Production and evaluation of YY-male Brook Trout to eradicate nonnative wild brook trout populations

    USGS Publications Warehouse

    Kennedy, Patrick; Schill, Daniel J.; Meyer, Kevin A.; Campbell, Matthew R.; Vu, Ninh V.; Hansen, Michael J.

    2017-01-01

    Nonnative Brook Trout Salvelinus fontinalis were introduced throughout western North America in the early 1900s, resulting in widespread self-sustaining populations that are difficult to eradicate and often threaten native salmonid populations. A novel approach for their eradication involves use of YY male (MYY) Brook Trout (created in the hatchery by feminizing XY males and crossing them with normal XY males). If MYY Brook Trout survive after stocking, and reproduce successfully with wild females, in theory this could eventually drive the sex ratio of the wild population to 100% males, at which point the population would not be able to reproduce and would be eradicated. This study represents the first successful development of a FYY and MYY salmonid broodstock, which was produced in four years at relatively low cost. Field trials demonstrated that stocked hatchery MYY Brook Trout survived and produced viable MYY offspring in streams, although reproductive fitness appeared to have been lower than their wild conspecifics. Even if reduced fitness is the norm in both streams and alpine lakes, our population simulations suggest that eradication can be achieved in reasonable time periods under some MYY stocking scenarios, especially when wild Brook Trout are simultaneously suppressed in the population.

  2. Viability criteria for steelhead of the south-central and southern California coast

    USGS Publications Warehouse

    Boughton, David A.; Adams, Peter B.; Anderson, Eric; Fusaro, Craig; Keller, Edward A.; Kelley, Elsie; Lentsch, Leo; Nielsen, Jennifer L.; Perry, Katie; Regan, Helen; Smith, Jerry; Swift, Camm C.; Thompson, Lisa; Watson, Fred

    2007-01-01

    Recovery planning for threatened and endangered steelhead requires measurable, objective criteria for determining an acceptably low risk of extinction. Here we propose viability criteria for two levels of biological organization: individual populations, and groups of populations within the SouthCentral/Southern California Coast Steelhead Recovery Planning Domain. For populations, we adapt criteria commonly used by the IUCN (The World Conservation Union) for identifying at-risk species. For groups of populations we implement a diversity-based “representation and redundancy rule,” in which diversity includes both life-history diversity and biogeographic groupings of populations. The resulting criteria have the potential for straightforward assessment of the risks posed by evolutionary, demographic, environmental, and catastrophic factors; and are designed to use data that are readily collected. However, our prescriptive approach led to one criterion whose threshold could not yet be specified due to inadequate data, and others in which the simplicity of the criteria may render them inefficient for populations with stable run sizes or stable life-history polymorphisms. Both of these problems could likely be solved by directed programs of research and monitoring aimed at developing more efficient (but equally risk-averse) “performance-based criteria.” Of particular utility would be data on the natural fluctuations of populations, research into the stabilizing influence of life-history polymorphisms, and research on the implications of drought, wildfires, and fluvial sediment regimes. Research on estuarine habitat could also yield useful information on the generality and reliability of its role as nursery habitat. Currently, risk assessment at the population level is not possible due to data deficiency, highlighting the need to implement a comprehensive effort to monitor run sizes, anadromous fractions, spawner densities and perhaps marine survival. Assessment at

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

    USGS Publications Warehouse

    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.

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

    USGS Publications Warehouse

    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.

  5. Aggression and feeding of hatchery-reared and naturally reared steelhead (Oncorhynchus mykiss) fry in a laboratory flume and a comparison with observations in natural streams

    USGS Publications Warehouse

    Riley, S.C.; Tatara, C.P.; Scheurer, J.A.

    2005-01-01

    We quantified the aggression and feeding of naturally reared steelhead (Oncorhynchus mykiss) fry stocked into a laboratory flume with naturally reared fry or hatchery-reared fry from conventional and enriched rearing environments at three densities in the presence and absence of predators, and compared the aggression and feeding observed in the flume to that observed in two streams. Steelhead fry attack rate increased with density and was reduced in the presence of predators, but was not affected by rearing treatment. Threat rate appeared to increase with density and was significantly affected by rearing treatment combination, but was not significantly affected by predator presence. Feeding rate was not affected by density or rearing treatment, but was reduced in the presence of predators. The rate of aggression by steelhead fry in two streams was lower than that observed in the laboratory and did not increase with density. Rates of aggression and feeding of hatchery-reared and wild steelhead fry were not significantly different in the streams. Overall, we found no evidence that hatchery rearing environments caused higher aggression in steelhead fry. Laboratory observations of salmonid aggression, particularly at high density, may not reflect aggression levels in the wild. ?? 2005 NRC.

  6. Trout hepatoma--a preliminary report

    USGS Publications Warehouse

    Rucker, R.R.; Yasutake, W.T.; Wolf, H.

    1961-01-01

    Fish pathology and its role in fish culture were brought into prominence in the spring of 1960 by the disclosure of a high incidence of hepatomas in hatchery-reared rainbow trout. The current problem came to light as the result of a routine inspection of live trout shipments at a California border fish-disease checking station. This service is performed by personnel of the California Department of Fish and Game to preclude the introduction or further spread of communicable fish diseases into California watersheds. Collaborative studies which followed revealed the nationwide distribution of the disease. This unusual disease soon attracted the attention of the Bureau of Sport Fisheries and Wildlife, the Food and Drug Administration, Public Health Service, and several western State health and conservation agencies.

  7. Factors influencing brown trout reproductive success in Ozark tailwater rivers

    USGS Publications Warehouse

    Pender, D.R.; Kwak, T.J.

    2002-01-01

    The reproductive success of brown trout Salmo trutta in White River, Arkansas, tailwater reaches is highly variable, resulting in the need for supplemental stocking. A better understanding of the physical and biotic factors affecting reproduction and survival would enhance the contribution of wild fish. We compared fecundity, reproductive chronology, physical habitat, water quality, trout density, food availability, diet, predation, and competitive interactions among four tailwater reaches to identify factors influencing brown trout reproductive success. The fecundity and condition factor of prespawning brown trout were significantly lower at Beaver Tailwater, a reach known for reproductive failure, than at other sites, among which no differences were found. Brown trout spawning was observed from 11 October to 23 November 1996, and juvenile emergence began on 28 February 1997. Significant among-site differences were detected for spawning and juvenile microhabitat variables, but the variables fell within or near suitable or optimal ranges reported in the literature for this species. Age-0 brown trout density differed significantly among sites, but growth and condition did not. Predation by Ozark sculpin Cottus hypselurus on trout eggs or age-0 trout of any species was not observed among the 418 stomachs examined. Ozark sculpin density and diet overlap with age-0 brown trout were highest and invertebrate food availability and water fertility were lowest at Beaver Tailwater relative to the other reaches. Our findings indicate that differences in trophic conditions occur among tailwater reaches, and a lower system productive capacity was identified at Beaver Tailwater. We suggest that management efforts include refining the multispecies trout stocking regime to improve production efficiency, enhancing flow regulation, and increasing habitat complexity to increase invertebrate and fish productivity. Such efforts may lead to improved natural reproduction and the

  8. Survival and growth of age-0 steelhead after surgical implantation of 23-mm passive integrated transponders

    USGS Publications Warehouse

    Bateman, D.S.; Gresswell, R.E.

    2006-01-01

    Little information is available on the effects of implanting 23-mm passive integrated transponder (PIT) tags in salmonids less than 90 mm fork length (FL). Using juvenile steelhead Oncorhynchus mykiss (range, 73–97 mm FL), we compared instantaneous growth rates and survival among three experimental groups: control, surgery with no tag, and surgery with tag. Survival rate was lower for tagged fish (86%) than for control and surgery−no tag fish (virtually 100% in each group). Approximately 90% of the mortalities occurred during days 1–3. Growth rate for the tagged group was lower for the first two 10-d measurement intervals; however, during the third 10-d interval, growth rates for tagged fish equaled or exceeded values for the other groups. These results suggest that tagged fish recovered by day 20. Growth rates for the control and surgery−no tag groups did not differ from one another during any measurement interval. Tag retention rate was 97% over the 30-d period of the study. It appears that the combination of fish length and tag size in this study resulted in short-term negative effects on growth rate and survival; however, 23-mm PIT tags may still be useful for studies of salmonids 80–90 mm FL when survival is not the parameter of interest.

  9. Physiological comparisons of plasma and tissue metrics of selected inland and coastal steelhead kelts.

    USGS Publications Warehouse

    Penney, Zachary L.; Moffitt, Christine M.; Jones, Bryan; Marston, Brian

    2016-01-01

    The physiological status of migrating steelhead kelts (Oncorhynchus mykiss) from the Situk River, Alaska, and two tributaries of the Clearwater River, Idaho, was evaluated to explore potential differences in post-spawning survival related to energy reserves. Blood plasma samples were analyzed for metrics related to nutritional and osmotic status, and samples of white muscle tissue collected from recent mortalities at weirs were analyzed for proximate constituents. Female kelts from the Situk River had significantly higher plasma cholesterol, triglycerides, glucose and calcium concentrations, all of which suggested higher lipid and energy stores. Additional support for energy limitation in kelts was provided by evaluating the presence of detectable proteins in the plasma. Most all kelts sampled from the Situk River populations had detectable plasma proteins, in contrast to kelts sampled from the Clearwater River tributary populations where 27 % of kelts from one tributary, and 68 % of the second tributary were below the limits of detection. We found proximate constituents of kelt mortalities were similar between the Situk and Clearwater River populations, and the lipid fraction of white muscle averaged 0.1 and 0.2 %. Our findings lend support to the hypothesis that energetic limitations likely affect post-spawn survival in the Clearwater River kelts.

  10. Movements and behavior of largemouth bass (Micropterus salmoides) and steelhead (Salmo gairdneri) determined by radio telemetry

    SciTech Connect

    Winter, J.D.

    1976-08-01

    The organization of this thesis reflects the development of underwater radio tracking methodology for monitoring movements of freshwater fish. Equipment and techniques developed during this research are described in Part I and represent a cooperative effort between the author and the University of Minnesota's Cedar Creek engineering staff. In 1970, the equipment and techniques were tested and perfected during a study of largemouth bass movements in Mary Lake. The bass project provided an ideal situation to test the system. Since Mary Lake was small and the bass exhibited localized movements, the fish could be found easily; consequently, the performance ofmore » the system could be continually analyzed and problems could be quickly solved. The home range movements of the bass are described in Part II. After establishing the reliability and usefulness of the system, a much more difficult project was attempted. In 1971, a program was initiated to study the movements and behavior of steelhead in western Lake Superior. Results of this project (1971 to 1974) are presented in Part III.« less

  11. Induction, isolation and a characterization of the lipid content of plasma vitellogenin from two Salmo species: rainbow trout (Salmo gairdneri) and sea trout (Salmo trutta).

    PubMed

    Norberg, B; Haux, C

    1985-01-01

    Vitellogenin synthesis is induced in juvenile rainbow trout (Salmo gairdneri) and juvenile sea trout (Salmo trutta) by estradiol-17 beta. A purification procedure for vitellogenin from trout plasma by precipitation with MgCl2-EDTA and subsequent anion exchange chromatography on DEAE-Sephacel is described. The total lipid contents of purified rainbow trout and sea trout vitellogenins are 18 and 19%, respectively. Approximately 2/3 of the lipids are phospholipids, while the remainder consists of triglycerides and cholesterol. Phosphorus determinations on delipidated vitellogenin yield a phosphorus content of 0.63% in rainbow trout and 0.58% in sea trout vitellogenin. Native (dimeric) vitellogenins from rainbow trout and sea trout both have an apparent molecular weight of 440,000, when estimated by gel filtration on Sepharose 6B.

  12. Brook trout passage performance through culverts

    USGS Publications Warehouse

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

    2016-01-01

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

  13. Spatial modeling to project Southern Appalachian Trout distribution in warmer climate

    Treesearch

    Patrica A. Flebbe; Laura D. Roghair; Jennifer L. Bruggink

    2006-01-01

    In the southern Appalachian Mountains, the distributions of native brook trout Salvelinus fontinalis and introduced rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta are presently limited by temperature and are expected to be limited further by a warmer climate. To estimate trout habitat in a future...

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

    Treesearch

    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

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

    USGS Publications Warehouse

    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.

  16. A watershed-scale monitoring protocol for bull trout

    Treesearch

    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...

  17. Greenback cutthroat trout (Oncorhynchus clarkii stomias): A technical conservation assessment

    Treesearch

    Michael K. Young

    2009-01-01

    Greenback cutthroat trout (Oncorhynchus clarkii stomias) was once presumably distributed throughout the colder waters of the South Platte and Arkansas River basins in Colorado and southeastern Wyoming. Primarily a fluvial species, greenback cutthroat trout may have occupied 10,614 to 13,231 km of streams above 1,800 m in these basins. Nevertheless,...

  18. Population Genetics of Boise Basin Bull Trout (Salvelinus confluentus)

    Treesearch

    A.R. Whiteley; P. Spruell; F.W. Allendorf

    2003-01-01

    We analyzed the population genetic structure of bull trout (Salvelinus confluentus) in the Boise River Basin, Idaho. We determined the influence of contemporary (including anthropogenic) and historic factors on genetic structure, taking into accountexisting data on bull trout habitat patches in this basin. We tested three models of the organization of genetic structure...

  19. Maturity schedules of lake trout in Lake Michigan

    USGS Publications Warehouse

    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.

  20. Status of the rainbow trout genome reference sequence assembly

    USDA-ARS?s Scientific Manuscript database

    Rainbow trout (Oncorhynchus mykiss) are the most cultivated cold water fish in the U.S. In addition to interests associated with aquaculture and sport fisheries, the rainbow trout serves as a model research organism for studies related to carcinogenesis, toxicology, comparative immunology, disease ...

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

    USGS Publications Warehouse

    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.

  2. The near extinction of lake trout in Lake Michigan

    USGS Publications Warehouse

    Eschmeyer, Paul H.

    1957-01-01

    Comparisons in 1949 and 1950 of numbers of legal-sized lake trout caught in large-mesh nets with numbers of small fish taken in chub nets showed that both large and small lake trout declined over the same period, and that by these years the decline may have been greater among small than among legal-sized fish.

  3. Ecological segregation moderates a climactic conclusion to trout hybridization

    Treesearch

    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...

  4. Demographic and habitat requirements for conservation of bull trout

    Treesearch

    Bruce E. Rieman; John D. Mclntyre

    1993-01-01

    Elements in bull trout biology, population dynamics, habitat, and biotic interactions important to conservation of the species are identified. Bull trout appear to have more specific habitat requirements than other salmonids, but no critical thresholds of acceptable habitat condition were found. Size, temporal variation, and spatial distribution are likely to influence...

  5. Weissellosis – An important emerging disease in farmed rainbow trout

    USDA-ARS?s Scientific Manuscript database

    Since 2007, disease outbreaks associated with Weissella sp. bacteria in cultured rainbow trout have been reported on farms in China and Brazil. In the summer and fall of 2011, we visited two trout farms in North Carolina to investigate reports of severe, prolonged mortalities in larger fish approach...

  6. Seasonal movement of brown trout in a southern Appalachian river

    Treesearch

    Kyle H. Burrell; J. Jeffery Isely; David B. Bunnell; David H. Van Lear; C. Andrew Dolloff

    2000-01-01

    Radio telemetry was used to evaluate the seasonal movement, activity level, and home range size of adult brown trout Salmo trutta in the Chattooga River watershed, one of the southernmost coldwater stream systems in the United States. In all, 27 adult brown trout (262-452 mm total length) were successfully monitored from 16 November 1995 to 15...

  7. A Runs-Test Algorithm: Contingent Reinforcement and Response Run Structures

    ERIC Educational Resources Information Center

    Hachiga, Yosuke; Sakagami, Takayuki

    2010-01-01

    Four rats' choices between two levers were differentially reinforced using a runs-test algorithm. On each trial, a runs-test score was calculated based on the last 20 choices. In Experiment 1, the onset of stimulus lights cued when the runs score was smaller than criterion. Following cuing, the correct choice was occasionally reinforced with food,…

  8. Metals-contaminated benthic invertebrates in the Clark Fork River, Montana: Effects on age-0 brown trout and rainbow trout

    USGS Publications Warehouse

    Woodward, Daniel F.; Farag, Aïda M.; Bergman, Harold L.; Delonay, Aaron J.; Little, Edward E.; Smiths, Charlie E.; Barrows, Frederic T.

    1995-01-01

    Benthic organisms in the upper Clark Fork River have recently been implicated as a dietary source of metals that may be a chronic problem for young-of-the-year rainbow trout (Oncorhynchus mykiss). In this present study, early life stage brown trout (Salmo trutta) and rainbow trout were exposed for 88 d to simulated Clark Fork River water and a diet of benthic invertebrates collected from the river. These exposures resulted in reduced growth and elevated levels of metals in the whole body of both species. Concentrations of As, Cd, Cu, and Pb increased in whole brown trout; in rainbow trout, As and Cd increased in whole fish, and As also increased in liver. Brown trout on the metals-contaminated diets exhibited constipation, gut impaction, increased cell membrane damage (lipid peroxidation), decreased digestive enzyme production (zymogen), and a sloughing of intestinal mucosal epithelial cells. Rainbow trout fed the contaminated diets exhibited constipation and reduced feeding activity. We believe that the reduced standing crop of trout in the Clark Fork River results partly from chronic effects of metals contamination in benthic invertebrates that are important as food for young-of-the-year fish.

  9. Golden trout habitat selection and movement patterns in degraded and recovering sites within the Golden Trout Wilderness, California

    Treesearch

    K.R. Matthews

    1996-01-01

    Abstract.—I used radio transmitters to determine habitat selection and movement patterns of California golden trout Oncorhynchus mykiss aguabonita in two areas defined by their different levels of habitat recovery in the Golden Trout Wilderness, California. Study areas were differentiated by the amount of streamside vegetation (low or high coverage of beaked sedge...

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

    USGS Publications Warehouse

    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.

  11. Compliance Monitoring of Juvenile Yearling Chinook Salmon and Steelhead Survival and Passage at The Dalles Dam, Spring 2010

    SciTech Connect

    Carlson, Thomas J.; Skalski, John R.

    2010-10-01

    The purpose of this compliance study was to estimate dam passage survival of yearling Chinook salmon and steelhead smolts at The Dalles Dam during spring 2010. Under the 2008 Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp), dam passage survival should be greater than or equal to 0.96 and estimated with a standard error (SE) less than or equal 0.015. The study also estimated smolt passage survival from the forebay boat-restricted zone (BRZ) to the tailrace BRZ at The Dalles Dam, as well as the forebay residence time, tailrace egress, and spill passage efficiency (SPE), as required in themore » Columbia Basin Fish Accords. A virtual/paired-release design was used to estimate dam passage survival at The Dalles Dam. The approach included releases of acoustic-tagged smolts above John Day Dam that contributed to the formation of a virtual release at the face of The Dalles Dam. A survival estimate from this release was adjusted by a paired release below The Dalles Dam. A total of 4,298 yearling Chinook salmon and 4,309 steelhead smolts were tagged and released in the investigation. The Juvenile Salmon Acoustic Telemetry System (JSATS) tag model number ATS-156dB, weighing 0.438 g in air, was used in this investigation. The dam passage survival results are summarized as follows: Yearling Chinook Salmon 0.9641 (SE = 0.0096) and Steelhead 0.9535 (SE = 0.0097).« less

  12. Migration depths of juvenile Chinook salmon and steelhead relative to total dissolved gas supersaturation in a Columbia River reservoir

    USGS Publications Warehouse

    Beeman, J.W.; Maule, A.G.

    2006-01-01

    The in situ depths of juvenile salmonids Oncorhynchus spp. were studied to determine whether hydrostatic compensation was sufficient to protect them from gas bubble disease (GBD) during exposure to total dissolved gas (TDG) supersaturation from a regional program of spill at dams meant to improve salmonid passage survival. Yearling Chinook salmon O. tshawytscha and juvenile steelhead O. mykiss implanted with pressure-sensing radio transmitters were monitored from boats while they were migrating between the tailrace of Ice Harbor Dam on the Snake River and the forebay of McNary Dam on the Columbia River during 1997-1999. The TDG generally decreased with distance from the tailrace of the dam and was within levels known to cause GBD signs and mortality in laboratory bioassays. Results of repeated-measures analysis of variance indicated that the mean depths of juvenile steelhead were similar throughout the study area, ranging from 2.0 m in the Snake River to 2.3 m near the McNary Dam forebay. The mean depths of yearling Chinook salmon generally increased with distance from Ice Harbor Dam, ranging from 1.5 m in the Snake River to 3.2 m near the forebay. Juvenile steelhead were deeper at night than during the day, and yearling Chinook salmon were deeper during the day than at night. The TDG level was a significant covariate in models of the migration depth and rates of each species, but no effect of fish size was detected. Hydrostatic compensation, along with short exposure times in the area of greatest TDG, reduced the effects of TDG exposure below those generally shown to elicit GBD signs or mortality. Based on these factors, our results indicate that the TDG limits of the regional spill program were safe for these juvenile salmonids.

  13. Variation in the Early Marine Survival and Behavior of Natural and Hatchery-Reared Hood Canal Steelhead

    PubMed Central

    Moore, Megan; Berejikian, Barry A.; Tezak, Eugene P.

    2012-01-01

    Background Hatchery-induced selection and direct effects of the culture environment can both cause captively bred fish populations to survive at low rates and behave unnaturally in the wild. New approaches to fish rearing in conservation hatcheries seek to reduce hatchery-induced selection, maintain genetic resources, and improve the survival of released fish. Methodology/Principal Findings This study used acoustic telemetry to compare three years of early marine survival estimates for two wild steelhead populations to survival of two populations raised at two different conservation hatcheries located within the Hood Canal watershed. Steelhead smolts from one conservation hatchery survived with probabilities similar to the two wild populations (freshwater: 95.8–96.9%, early marine: 10.0–15.9%), while smolts from the other conservation hatchery exhibited reduced freshwater and early marine survival (freshwater: 50.2–58.7%, early marine: 2.6–5.1%). Freshwater and marine travel rates did not differ significantly between wild and hatchery individuals from the same stock, though hatchery smolts did display reduced migration ranges within Hood Canal. Between-hatchery differences in rearing density and vessel geometry likely affected survival and behavior after release and contributed to greater variation between hatcheries than between wild populations. Conclusions/Significance Our results suggest that hatchery-reared smolts can achieve early marine survival rates similar to wild smolt survival rates, and that migration performance of hatchery-reared steelhead can vary substantially depending on the environmental conditions and practices employed during captivity. PMID:23185393

  14. Proposed standard-weight (W(s)) equations for kokanee, golden trout and bull trout

    USGS Publications Warehouse

    Hyatt, M.H.; Hubert, W.A.

    2000-01-01

    We developed standard-weight (W(s)) equations for kokanee (lacustrine Oncorhynchus nerka), golden trout (O. aguabonita), and bull trout (Salvelinus confluentus) using the regression-line-percentile technique. The W(s) equation for kokanee of 120-550 mm TL is log10 W(s) = -5.062 + 3.033 log10 TL, when W(s) is in grams and TL is total length in millimeters; the English-unit equivalent is log10 W(s) = -3.458 + 3.033 log10 TL, when W(s) is in pounds and TL is total length in inches. The W(s) equation for golden trout of 120-530 mm TL is log10 W(s) = -5.088 + 3.041 log10 TL, with the English-unit equivalent being log10 W(s) = -3.473 + 3.041 log10 TL. The W(s) equation for bull trout of 120-850 mm TL is log10 W(s) = -5.327 + 3.115 log10 TL, with the English-unit equivalent being log10 W(s) = -3.608 + 3.115 log10 TL.

  15. Natural Reproductive Success and Demographic Effects of Hatchery-Origin Steelhead in Abernathy Creek, Washington : Annual Report 2008.

    SciTech Connect

    U.S. Fish & Wildlife Service, Abernathy Fish Technology Center

    2008-12-01

    Many hatchery programs for steelhead pose genetic or ecological risks to natural populations because those programs release or outplant fish from non-native stocks. The goal of many steelhead programs has been to simply provide 'fishing opportunities' with little consideration given to conservation concerns. For example, the Washington Department of Fish and Wildlife (WDFW) has widely propagated and outplanted one stock of winter-run steelhead (Chambers Creek stock) and one stock of summer-run steelhead (Skamania stock) throughout western Washington. Biologists and managers now recognize potential negative effects can occur when non-native hatchery fish interact biologically with native populations. Not only do non-nativemore » stocks pose genetic and ecological risks to naturally spawning populations, but non-native fish stray as returning adults at a much higher rate than do native fish (Quinn 1993). Biologists and managers also recognize the need to (a) maintain the genetic resources associated with naturally spawning populations and (b) restore or recover natural populations wherever possible. As a consequence, the U.S. Fish & Wildlife Service (USFWS) and the NOAA Fisheries have been recommending a general policy that discourages the use of non-native hatchery stocks and encourages development of native broodstocks. There are two primary motivations for these recommendations: (1) reduce or minimize potential negative biological effects resulting from genetic or ecological interactions between hatchery-origin and native-origin fish and (2) use native broodstocks as genetic repositories to potentially assist with recovery of naturally spawning populations. A major motivation for the captive-rearing work described in this report resulted from NOAA's 1998 Biological Opinion on Artificial Propagation in the Columbia River Basin. In that biological opinion (BO), NOAA concluded that non-native hatchery stocks of steelhead jeopardize the continued existence of U

  16. Compliance Monitoring of Yearling and Subyearling Chinook Salmon and Juvenile Steelhead Survival and Passage at John Day Dam, 2012

    SciTech Connect

    Skalski, J. R.; Townsend, Richard L.; Seaburg, Adam

    2013-05-01

    The purpose of this compliance study was to estimate dam passage survival of yearling and subyearling Chinook salmon and steelhead smolts at John Day Dam during the spring and summer outmigrations in 2012. Under the 2008 Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp), dam passage survival should be greater than or equal to 0.96 for spring migrants and greater than or equal to 0.93 for summer migrants, estimated with a standard error (SE) less than or equal to 0.015. The study also estimated smolt passage survival from the forebay 2 km upstream of the dam to the tailracemore » 3 km downstream of the dam, as well as the forebay residence time, tailrace egress time, spill passage efficiency (SPE), and fish passage efficiency (FPE), as required in the Columbia Basin Fish Accords (Fish Accords). A virtual/paired-release design was used to estimate dam passage survival at John Day Dam. The approach included releases of smolts, tagged with acoustic micro-transmitters, above John Day Dam that contributed to the formation of a virtual release at the face of John Day Dam. A survival estimate from this release was adjusted by a paired release below John Day Dam. A total of 3376 yearling Chinook salmon, 5726 subyearling Chinook salmon, and 3239 steelhead smolts were used in the virtual releases. Sample sizes for the below-dam paired releases (R2 and R3, respectively) were 997 and 995 for yearling Chinook salmon smolts, 986 and 983 for subyearling Chinook salmon smolts, and 1000 and 1000 for steelhead smolts. The Juvenile Salmon Acoustic Telemetry System (JSATS) tags were manufactured by Advanced Telemetry Systems. Model SS300 tags, weighing 0.304 g in air, were surgically implanted in yearling and subyearling Chinook salmon, and Model SS130 tag, weighing 0.438 g in air, were surgically implanted in juvenile steelhead for this investigation. The intent of the spring study was to estimate dam passage survival during both 30% and 40% spill conditions. The

  17. Protocol for determining bull trout presence

    USGS Publications Warehouse

    Peterson, James; Dunham, Jason B.; Howell, Philip; Thurow, Russell; Bonar, Scott

    2002-01-01

    The Western Division of the American Fisheries Society was requested to develop protocols for determining presence/absence and potential habitat suitability for bull trout. The general approach adopted is similar to the process for the marbled murrelet, whereby interim guidelines are initially used, and the protocols are subsequently refined as data are collected. Current data were considered inadequate to precisely identify suitable habitat but could be useful in stratifying sampling units for presence/absence surveys. The presence/absence protocol builds on previous approaches (Hillman and Platts 1993; Bonar et al. 1997), except it uses the variation in observed bull trout densities instead of a minimum threshold density and adjusts for measured differences in sampling efficiency due to gear types and habitat characteristics. The protocol consists of: 1. recommended sample sizes with 80% and 95% detection probabilities for juvenile and resident adult bull trout for day and night snorkeling and electrofishing adjusted for varying habitat characteristics for 50m and 100m sampling units, 2. sampling design considerations, including possible habitat characteristics for stratification, 3. habitat variables to be measured in the sampling units, and 3. guidelines for training sampling crews. Criteria for habitat strata consist of coarse, watershed-scale characteristics (e.g., mean annual air temperature) and fine-scale, reach and habitat-specific features (e.g., water temperature, channel width). The protocols will be revised in the future using data from ongoing presence/absence surveys, additional research on sampling efficiencies, and development of models of habitat/species occurrence.

  18. NITRO MUSK ADDUCTS OF RAINBOW TROUT ...

    EPA Pesticide Factsheets

    Rainbow trout and other fish species can serve as 'sentinel' species for the assessment of ecological status and the presence of certain environmental contaminants. As such they act as bioindicators of exposure. Here we present seminal data regarding dose-response and toxicokinetics of trout hemoglobin adduct formation from exposure to nitro musks that are frequently used as fragrance ingredients in formulations of personal care products. Hemoglobin adducts serve as biomarkers of exposure of the sentinel species as we have shown in previous studies of hemoglobin adducts formed in trout and environmental carp exposed to musk xylene (MX) and musk ketone (MK). Gas chromatography-electron capture negative ion chemical ionization-mass spectrometry (GC-NICI-MS) employing selected ion monitoring is used to measure 4-amino-MX (4-AMX), 2-amino-MX (2-AMX), and 2-amino-MK (2-AMK) released by alkaline hydrolysis from the sulfinamide adducts of hemoglobin. Dose-response and toxicokinetics were investigated using this sensitive method for analysis of these metabolites. In the dose-response investigation, the concentrations of 4-AMX and 2-2AMX are observed to pass through a maximum at 0.10 mg/g. In the case of 2-AMK, the adduct concentration is almost the same at dosages in the range of 0.030 to 0.10 mg/g. For toxicokinetics, the concentration of the metabolites in the Hb reaches a maximum in the 3-day sample after administration of MX or MK. Further elimination of the metabo

  19. Reevaluation of lake trout and lake whitefish bioenergetics models

    USGS Publications Warehouse

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

    2013-01-01

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

  20. Lake trout rehabilitation in Lake Erie: a case history

    USGS Publications Warehouse

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

    1995-01-01

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

  1. The chemical disinfection of trout ponds

    USGS Publications Warehouse

    Fish, F.F.

    1933-01-01

    The need for knowledge concerning the prevention and control of fish diseases has never been greater than it is in this present era of economy when two fish must be raised in the same water which once supported but one. Fish pathologists have contributed a great deal to our knowledge of fish diseases, but there is still much to be learned, particularly concerning better methods of preventing and eliminating diseases among our trout. In this era of circular pools and raceways, our disease elimination is way back in the early days of standard troughs.

  2. An obscure disease of rainbow trout

    USGS Publications Warehouse

    Rucker, R.R.; Yasutake, W.T.; Wedemeyer, G.

    1970-01-01

    An annul mortality among Rainbow Trout (Salmo gairdneri) has plagued the Shelton Hatchery of the Washington State Department of Game for the last several years. No infectious agent could be isolated from the moribund fish, but histopathologica1 changes in the liver of 1-month-old fish suggested the presence of a toxic substance. Scoliosis in 3-month-old fish suggested a possible deficiency in vitamin C. With this background in mind, we designed studies to determine the nature and source of possible toxicants and the role of vitamin C deficiency in the etiology of this disease.

  3. Introduced brown trout alter native acanthocephalan infections in native fish.

    PubMed

    Paterson, Rachel A; Townsend, Colin R; Poulin, Robert; Tompkins, Daniel M

    2011-09-01

    1. Native parasite acquisition provides introduced species with the potential to modify native host-parasite dynamics by acting as parasite reservoirs (with the 'spillback' of infection increasing the parasite burdens of native hosts) or sinks (with the 'dilution' of infection decreasing the parasite burdens of native hosts) of infection. 2. In New Zealand, negative correlations between the presence of introduced brown trout (Salmo trutta) and native parasite burdens of the native roundhead galaxias (Galaxias anomalus) have been observed, suggesting that parasite dilution is occurring. 3. We used a multiple-scale approach combining field observations, experimental infections and dynamic population modelling to investigate whether native Acanthocephalus galaxii acquisition by brown trout alters host-parasite dynamics in native roundhead galaxias. 4. Field observations demonstrated higher infection intensity in introduced trout than in native galaxias, but only small, immature A. galaxii were present in trout. Experimental infections also demonstrated that A. galaxii does not mature in trout, although parasite establishment and initial growth were similar in the two hosts. Taken together, these results support the hypothesis that trout may serve as an infection sink for the native parasite. 5. However, dynamic population modelling predicts that A. galaxii infections in native galaxias should at most only be slightly reduced by dilution in the presence of trout. Rather, model exploration indicates parasite densities in galaxias are highly sensitive to galaxias predation on infected amphipods, and to relative abundances of galaxias and trout. Hence, trout presence may instead reduce parasite burdens in galaxias by either reducing galaxias density or by altering galaxias foraging behaviour. © 2011 The Authors. Journal of Animal Ecology © 2011 British Ecological Society.

  4. Route-Specific Passage and Survival of Steelhead Kelts at The Dalles and Bonneville Dams, 2012 - Final Report

    SciTech Connect

    Rayamajhi, Bishes; Ploskey, Gene R.; Woodley, Christa M.

    2013-07-31

    This study was mainly focused on evaluating the route-specific passage and migration success of steelhead kelts passing downstream through The Dalles Dam (TDA) and Bonneville Dam (BON) at Columbia River (CR) river kilometers 309 and 234 respectively. Oregon Department of Fish and Wildlife (ODFW) personnel collected, tagged and released out-migrating steelhead kelts in the tributaries of the Deschutes River, 15 Mile Creek and Hood River between April 14 and June 4, 2012. A PIT tag was injected into each kelt’s dorsal sinus whereas a Juvenile Salmon Acoustic Telemetry System (JSATS) acoustic micro-transmitter was attached to an external FLoy T-bar tagmore » and inserted into the dorsal back musculature using a Floy tagging gun. JSATS cabled arrays were deployed at TDA and BON and autonomous node arrays were deployed near Celilo, Oregon (CR325); the BON forebay (CR236); the BON tailrace (CR233); near Knapp, Washington (CR156); and near Kalama, Washington (CR113) to monitor the kelts movement while passing through the dams and above mentioned river cross-sections.« less

  5. The evolutionary history of steelhead (Oncorhynchus mykiss) along the US Pacific Coast: Developing a conservation strategy using genetic diversity

    USGS Publications Warehouse

    Nielsen, J.L.

    1999-01-01

    Changes in genetic variation across a species range may indicate patterns of population structure resulting from past ecological and demographic events that are otherwise difficult to infer and thus provide insight into evolutionary development. Genetic data is used, drawn from 11 microsatellite loci amplified from anadromous steelhead (Oncorhynchus mykiss) sampled throughout its range in the eastern Pacific Ocean, to explore population structure at the southern edge in California. Steelhead populations in this region represent less than 10% of their reported historic abundance and survive in very small populations found in fragmented habitats. Genetic data derived from three independent molecular systems (allozymes, mtDNA, and microsatellites) have shown that the southernmost populations are characterized by a relatively high genetic diversity. Two hypothetical models supporting genetic population substructure such as observed were considered: (1) range expansion with founder-flush effects and subsequent population decline; (2) a second Pleistocene radiation from the Gulf of California. Using genetic and climatic data, a second Pleistocene refugium contributing to a southern ecotone seems more feasible. These data support strong conservation measures based on genetic diversity be developed to ensure the survival of this uniquely diverse gene pool.

  6. Vaccination of rainbow trout against infectious hematopoietic necrosis (IHN) by using attenuated mutants selected by neutralizing monoclonal antibodies

    USGS Publications Warehouse

    Roberti, K.A.; Rohovec, J.S.; Winton, J.R.

    1998-01-01

    A neutralizing monoclonal antibody against infectious hematopoietic necrosis virus (IHNV) was used to select neutralization-resistant mutants from isolates of virus obtained from adult steelhead Oncorhynchus mykiss returning to the Round Butte Hatchery (RB mutants) on the Deschutes River in Oregon, USA, and from rainbow trout (nonanadromous O. mykiss) at a commercial hatchery in the Hagerman Valley of Idaho, USA (193-110 mutants). Two of the mutants, RB-1 and 193-110-4, were significantly (P 0.05) in protection among fish exposed to the RB-1 vaccine strain at a dose of 1 x 105 TCID50/mL for periods of either 1, 12, or 24 h, held for 14 d, and then challenged with the wild-type RB isolate, although the 1-h exposure seemed to be somewhat less effective. Fish were vaccinated with the RB-1 strain at 1 x 103-1 x 105 TCID50/mL for 24 h then challenged after 1, 7, 14, or 21 d with the wild-type RB isolate. No significant (P > 0.1) protection was observed at 1 d postvaccination, but the relative percent survival increased progressively at each subsequent challenge period, becoming statistically significant by day 7 (P < 0.001) and beyond. These results suggested that resistance to challenge with wild-type virus resulted from development of IHNV-specific immunity and not from viral interference or interferon induction, and they reinforce the potential of an attenuated vaccine to control this important disease.

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

    USGS Publications Warehouse

    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.

  8. Diel movement and habitat use of the golden trout Oncorhynchus mykiss aguabonita in their native habitat on the Golden Trout Wilderness, California

    Treesearch

    K.R. Matthews

    1996-01-01

    Abstract.—I used radio transmitters to determine the diel habitat use and movement patterns of California golden trout Oncorhynchus mykiss aquabonita inside and outside cattle exclosures on the South Fork Kern River, Golden Trout Wilderness, California. Twenty-three golden trout were monitored from September 10 to 19, 1993, during 216 diel-tracking hours at four study...

  9. Behavioral and histological effects of acrylamide in rainbow trout.

    PubMed

    Petersen, D W; Cooper, K R; Friedman, M A; Lech, J J

    1987-01-01

    A histological and behavioral study was used to assess whether acrylamide produced neurotoxic effects in rainbow trout. Swimming performance of trout exposed to 0, 12.5, or 25 mg/liter acrylamide for 15 days was unaffected. Swimming performance of animals exposed to 50 mg/liter acrylamide for a similar time period was compromised by morbidity and mortality of the animals in this treatment group. The absence of dose-related histological lesions in central neurons, peripheral neurons or muscle suggested that the observed deficit in swimming performance was due to a generalized toxic response. Acrylamide treatment produced dose-related lesions in the gill and liver of rainbow trout.

  10. Ice processes affect habitat use and movements of adult cutthroat trout and brook trout in a Wyoming foothills stream

    USGS Publications Warehouse

    Lindstrom, J.W.; Hubert, W.A.

    2004-01-01

    Habitat use and movements of 25 adult cutthroat trout Oncorhynchus clarkii and 25 adult brook trout Salvelinus fontinalis from fall through winter 2002-2003 were assessed by means of radiotelemetry in a 7-km reach of a Rocky Mountains foothills stream. Temporal dynamics of winter habitat conditions were evaluated by regularly measuring the features of 30 pools and 5 beaver Castor canadensis ponds in the study reach. Groundwater inputs at three locations raised mean daily water temperatures in the stream channel during winter to 0.2-0.6??C and kept at least 250 m of the downstream channel free of ice, but the lack of surface ice further downstream led to the occurrence of frazil ice and anchor ice in pools and unstable habitat conditions for trout. Pools in segments that were not affected by groundwater inputs and beaver ponds tended to be stable and snow accumulated on the surface ice. Pools throughout the study reach tended to become more stable as snow accumulated. Both cutthroat trout and brook trout selected beaver ponds as winter progressed but tended to use lateral scour pools in proportion to their availability. Tagged fish not in beaver ponds selected lateral scour pools that were deeper than average and stable during winter. Movement frequencies by tagged fish decreased from fall through winter, but some individuals of both species moved during winter. Ice processes affected both the habitat use and movement patterns of cutthroat trout and brook trout in this foothills stream.

  11. Genetic characterization of hybridization and introgression between anadromous rainbow trout (oncorhynchus mykiss irideus) and coastal cutthroat trout (o. clarki clarki)

    USGS Publications Warehouse

    Young, W.P.; Ostberg, C.O.; Keim, P.; Thorgaard, G.H.

    2001-01-01

    Interspecific hybridization represents a dynamic evolutionary phenomenon and major conservation problem in salmonid fishes. In this study we used amplified fragment length polymorphisms (AFLP) and mitochondrial DNA (mtDNA) markers to describe the extent and characterize the pattern of hybridization and introgression between coastal rainbow trout (Oncorhynchus mykiss irideus) and coastal cutthroat trout (O. clarki clarki). Hybrid individuals were initially identified using principle coordinate analysis of 133 polymorphic AFLP markers. Subsequent analysis using 23 diagnostic AFLP markers revealed the presence of F1, rainbow trout backcross, cutthroat trout backcross and later-generation hybrids. mtDNA analysis demonstrated equal numbers of F1 hybrids with rainbow and cutthroat trout mtDNA indicating reciprocal mating of the parental types. In contrast, rainbow and cutthroat trout backcross hybrids always exhibited the mtDNA from the recurrent parent, indicating a male hybrid mating with a pure female. This study illustrates the usefulness of the AFLP technique for generating large numbers of species diagnostic markers. The pattern of hybridization raises many questions concerning the existence and action of reproductive isolating mechanisms between these two species. Our findings are consistent with the hypothesis that introgression between anadromous populations of coastal rainbow and coastal cutthroat trout is limited by an environment-dependent reduction in hybrid fitness.

  12. Factors Affecting Route Selection and Survival of Steelhead Kelts at Snake River Dams in 2012 and 2013

    SciTech Connect

    Harnish, Ryan A.; Colotelo, Alison HA; Li, Xinya

    2014-12-01

    In 2012 and 2013, Pacific Northwest National Laboratory conducted a study that summarized the passage proportions and route-specific survival rates of steelhead kelts that passed through Federal Columbia River Power System (FCRPS) dams. To accomplish this, a total of 811 steelhead kelts were tagged with Juvenile Salmon Acoustic Telemetry System (JSATS) transmitters. Acoustic receivers, both autonomous and cabled, were deployed throughout the FCRPS to monitor the downstream movements of tagged-kelts. Kelts were also tagged with Passive Integrated Transponder tags to monitor passage through juvenile bypass systems and detect returning fish. The current study evaluated data collected in 2012 and 2013more » to identify individual, behavioral, environmental and dam operation variables that were related to passage and survival of steelhead kelts that passed through FCRPS dams. Bayesian model averaging of multivariable logistic regression models was used to identify the environmental, temporal, operational, individual, and behavioral variables that had the highest probability of influencing the route of passage and the route-specific survival probabilities for kelts that passed Lower Granite (LGR), Little Goose (LGS), and Lower Monumental (LMN) dams in 2012 and 2013. The posterior probabilities of the best models for predicting route of passage ranged from 0.106 for traditional spill at LMN to 0.720 for turbine passage at LGS. Generally, the behavior (depth and near-dam searching activity) of kelts in the forebay appeared to have the greatest influence on their route of passage. Shallower-migrating kelts had a higher probability of passing via the weir and deeper-migrating kelts had a higher probability of passing via the JBS and turbines than other routes. Kelts that displayed a higher level of near-dam searching activity had a higher probability of passing via the spillway weir and those that did less near-dam searching had a higher probability of passing via the JBS

  13. The effects of increased stream temperatures on juvenile steelhead growth in the Yakima River Basin based on projected climate change scenarios

    USGS Publications Warehouse

    Hardiman, Jill M.; Mesa, Matthew G.

    2013-01-01

    Stakeholders within the Yakima River Basin expressed concern over impacts of climate change on mid-Columbia River steelhead (Oncorhynchus mykiss), listed under the Endangered Species Act. We used a bioenergetics model to assess the impacts of changing stream temperatures—resulting from different climate change scenarios—on growth of juvenile steelhead in the Yakima River Basin. We used diet and fish size data from fieldwork in a bioenergetics model and integrated baseline and projected stream temperatures from down-scaled air temperature climate modeling into our analysis. The stream temperature models predicted that daily mean temperatures of salmonid-rearing streams in the basin could increase by 1–2°C and our bioenergetics simulations indicated that such increases could enhance the growth of steelhead in the spring, but reduce it during the summer. However, differences in growth rates of fish living under different climate change scenarios were minor, ranging from about 1–5%. Because our analysis focused mostly on the growth responses of steelhead to changes in stream temperatures, further work is needed to fully understand the potential impacts of climate change. Studies should include evaluating changing stream flows on fish activity and energy budgets, responses of aquatic insects to climate change, and integration of bioenergetics, population dynamics, and habitat responses to climate change.

  14. Status and distribution of chinook salmon and steelhead in the interior Columbia River basin and portions of the Klamath River basin [Chapter 12

    Treesearch

    Russell F. Thurow; Danny C. Lee; Bruce E. Rieman

    2000-01-01

    This chapter summarizes information on presence, absence, current status, and probable historical distribution of steelhead Oncorhynchus mykiss and stream-type (age-1 migrant) and ocean type (age-0 migrant) chinook salmon O. tshawytscha in the interior Columbia River basin and portions of the Klamath River basin. Data were compiled from existing sources and via surveys...

  15. Seasonal use of small tributary and main-stem habitats by juvenile steelhead, coho salmon, and Dolly Varden in a southeastern Alaska drainage basin.

    Treesearch

    R.G. Bramblett; M.D. Bryant; B.E. Wright; R.G. White

    2002-01-01

    The movement of juvenile salmonids between small tributaries and main-stem habitats in southeast Alaska watersheds is poorly understood. We observed movements of steelhead Oncorhynchus mykiss, coho salmon O. kisutch, and Dolly Varden Salvelinus malma between mainstem and tributary habitats at weirs located...

  16. Seasonal variation in diel behaviour and habitat use by age 1+ steelhead (Oncorhynchus mykiss) in Coast and Cascade Range streams in Oregon, U.S.A

    Treesearch

    Gordon H. Reeves; Jon B. Grunbaum; Dirk W. Lang

    2009-01-01

    The seasonal diel behaviour of age 1+ steelhead from Coast and Cascade Range streams in Oregon was examined in the field and in laboratory streams. During the summer, fish from both areas were active during the day in natural streams: they held position in the water column in moderate velocities and depths. At night, fish were in slower water, closer to the bottom...

  17. Spatial ecological processes and local factors predict the distribution and abundance of spawning by steelhead (Oncorhynchus mykiss) across a complex riverscape

    Treesearch

    Jeffrey A. Falke; Jason B. Dunham; Christopher E. Jordan; Kristina M. McNyset; Gordon H. Reeves

    2013-01-01

    Processes that influence habitat selection in landscapes involve the interaction of habitat composition and configuration and are particularly important for species with complex life cycles. We assessed the relative influence of landscape spatial processes and local habitat characteristics on patterns in the distribution and abundance of spawning steelhead (...

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

    USGS Publications Warehouse

    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. Toxicokinetics of perfluorooctanoate (PFOA) in rainbow trout ...

    EPA Pesticide Factsheets

    Perfluoroalkyl acids (PFAAs) are widely used as stain resistant coatings for cloth, paper, and leather, and as surfactants, fire-fighting foams, and photographic developers. Individual PFAAs have been shown to accumulate in fish and wildlife; however, the extent of this accumulation varies widely. In general, the tendency of individual PFAAs to accumulate in fish is directly related to the length of a compound’s fluorinated carbon chain as well as the identity of the terminal group (sulfonate or carboxylate) which confers to the molecule its amphipathic character. Presently, however the mechanisms that underly these observations remain poorly understood. In the present study we investigated the kinetics of perfluorooctanoic acid (PFOA) in rainbow trout. PFOA is not accumulated by fish. We also know that it is eliminated by mammals in urine. Our hypothesis, therefore, was that renal elimination of PFOA limits its accumulation in fish. Trout injected with an intra-arterial dose of PFOA were sampled to obtain concentration time-course data for plasma, urine, and expired water. The data were then analyzed by compartmental modeling to estimate rates of renal and branchial clearance. Averaged across all animals, the renal clearance rate was about ten times higher than the branchial clearance rate, confirming our hypothesis. The results of this effort provide a clear explanation for the observed absence of PFOA accumulation in fish. Moreover, these results suggest th

  20. Bi-parentally inherited species-specific markers identify hybridization between rainbow trout and cutthroat trout subspecies

    USGS Publications Warehouse

    Ostberg, C.O.; Rodriguez, R.J.

    2004-01-01

    Eight polymerase chain reaction primer sets amplifying bi-parentally inherited species-specific markers were developed that differentiate between rainbow trout (Oncorhynchus mykiss) and various cutthroat trout (O. clarki) subspecies. The primers were tested within known F1 and first generation hybrid backcrosses and were shown to amplify codominantly within hybrids. Heterozygous individuals also amplified a slower migrating band that was a heteroduplex, caused by the annealing of polymerase chain reaction products from both species. These primer sets have numerous advantages for native cutthroat trout conservation including statistical genetic analyses of known crosses and simple hybrid identification.

  1. View west of reserve basin of submarine trout and frigate ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View west of reserve basin of submarine trout and frigate Edward E. McDonnell - Naval Base Philadelphia-Philadelphia Naval Shipyard, Reserve Basin & Marine Railway, League Island, Philadelphia, Philadelphia County, PA

  2. Metabolism of 7-ethyoxycoumarin by Isolated Perfused Rainbow Trout Livers

    EPA Science Inventory

    Isolated trout livers were perfused using methods designed to preserve tissue viability and function. Liver performance was evaluated by measuring O2 consumption, vascular resistance, K+ leakage, glucose flux, lactate flux, alanine aminotransferase leakage, and metabolic clearanc...

  3. Comparison of biochemical parameters of rainbow trout (Oncorhynchus mykiss) reared in two different trout farms'

    NASA Astrophysics Data System (ADS)

    Karatas, Tayfun

    2016-04-01

    The aim of this study was to compare biochemical parameters of cultured rainbow trouts (Oncorhynchus mykiss, Walbaum, 1972) reared in two different trout farms' (Agri and Erzurum). The average weights of fish were 150±10gr for first station (Agri), 230±10gr for second station (Erzurum). Fishes used in research were randomly caught from pools, and fifteen pieces were used for each group. Fishes were fed with commercial trout feed with 45-50% crude protein twice a day. The levels of AST, ALT, LDL, total cholesterol and triglyceride in the second station (Erzurum) were found to be higher (p<0.05) than that of first station (Agri). Whereas, the levels of HDL in the second station (Erzurum) were found to be lower (p<0.05) than that of first station (Agri). Differences in the levels of total cholesterol and AST, ALT, HDL, LDL, triglyceride may be associated with size, sex, sexual maturity and environmental conditions (temperature, pH, hardness and dissolved oxygen).

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

    USGS Publications Warehouse

    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. Conservation of native Pacific trout diversity in western North America

    USGS Publications Warehouse

    Penaluna, Brooke E.; Abadía-Cardoso, Alicia; Dunham, Jason B.; García de León, Francisco J; Gresswell, Robert E.; Luna, Arturo Ruiz; Taylor, Eric B.; Shepard, Bradley B.; Al-Chokhachy, Robert K.; Muhlfeld, Clint C.; Bestgen, Kevin R.; Rogers, Kevin H.; Escalante, Marco A; Keeley, Ernest R; Temple, Gabriel; Williams, Jack E.; Matthews, Kathleen; Pierce, Ron; Mayden, Richard L.; Kovach, Ryan; Garza, John Carlos; Fausch, Kurt D.

    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 the state of knowledge on these important issues, focusing on Pacific trout in the genus Oncorhynchus. Although most research on salmonid fishes emphasizes Pacific salmon, we focus on Pacific trout because they share a common evolutionary history, and many taxa in western North America have not been formally described, particularly in the southern extent of their ranges. Research in recent decades has led to the revision of many hypotheses concerning the origin and diversification of Pacific trout throughout their range. Although there has been significant success at addressing past threats to Pacific trout, contemporary and future threats represented by nonnative species, land and water use activities, and climate change pose challenges and uncertainties. Ultimately, conservation of Pacific trout depends on how well these issues are understood and addressed, and on solutions that allow these species to coexist with a growing scope of human influences.

  6. Seasonal movement of brown trout in the Clinch River, Tennessee

    USGS Publications Warehouse

    Bettinger, J.M.; Bettoli, P.W.

    2004-01-01

    We used radiotelemetry to monitor the seasonal movements of trophy-size brown trout Salmo trutta in the Clinch River below Norris Dam, Tennessee, to determine whether establishing a special-regulation reach to reduce fishing mortality was a viable management option. Fifteen brown trout (size range, 430-573 mm total length) collected from the river were implanted with radio transmitters between November 1997 and May 1998. Forty-seven percent of these fish died or expelled their transmitters within 50 d postsurgery. The range of movement for surviving brown trout was significantly larger in fall (geometric mean range = 5,111 m) than in any other season. Four brown trout that were monitored for more than 1 year exhibited a limited range of movement (5 km) during the fall season, presumably to spawn. Brown trout also moved more during the fall than in any other season. Harvest restrictions applied to a specific reach of the Clinch River would reduce the exploitation of brown trout in that reach for most of the year but not during the fall, when many fish undertake extensive spawning migrations.

  7. Virulence of Flavobacterium columnare genomovars in rainbow trout Oncorhynchus mykiss.

    PubMed

    Evenhuis, Jason P; LaFrentz, Benjamin R

    2016-08-09

    Flavobacterium columnare is the causative agent of columnaris disease and is responsible for significant economic losses in aquaculture. F. columnare is a Gram-negative bacterium, and 5 genetic types or genomovars have been described based on restriction fragment length polymorphism of the 16S rRNA gene. Previous research has suggested that genomovar II isolates are more virulent than genomovar I isolates to multiple species of fish, including rainbow trout Oncorhynchus mykiss. In addition, improved genotyping methods have shown that some isolates previously classified as genomovar I, and used in challenge experiments, were in fact genomovar III. Our objective was to confirm previous results with respect to genomovar II virulence, and to determine the susceptibility of rainbow trout to other genomovars. The virulence of 8 genomovar I, 4 genomovar II, 3 genomovar II-B, and 5 genomovar III isolates originating from various sources was determined through 3 independent challenges in rainbow trout using an immersion challenge model. Mean cumulative percent mortality (CPM) of ~49% for genomovar I isolates, ~1% for genomovar II, ~5% for the II-B isolates, and ~7% for the III isolates was observed. The inability of genomovar II isolates to produce mortalities in rainbow trout was unanticipated based on previous studies, but may be due to a number of factors including rainbow trout source and water chemistry. The source of fish and/or the presence of sub-optimal environment may influence the susceptibility of rainbow trout to different F. columnare genomovars.

  8. Delineation of sympatric morphotypes of lake trout in Lake Superior

    USGS Publications Warehouse

    Moore, Seth A.; Bronte, Charles R.

    2001-01-01

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

  9. The floodplain food web mosaic: a study of its importance to salmon and steelhead with implications for their recovery

    USGS Publications Warehouse

    Bellmore, J. Ryan; Baxter, Colden V.; Martens, Kyle; Connolly, Patrick J.

    2013-01-01

    Although numerous studies have attempted to place species of interest within the context of food webs, such efforts have generally occurred at small scales or disregard potentially important spatial heterogeneity. If food web approaches are to be employed to manage species, studies are needed that evaluate the multiple habitats and associated webs of interactions in which these species participate. Here, we quantify the food webs that sustain rearing salmon and steelhead within a floodplain landscape of the Methow River, Washington, USA, a location where restoration has been proposed to restore side channels in an attempt to recover anadromous fishes. We combined year-long measures of production, food demand, and diet composition for the fish assemblage with estimates of invertebrate prey productivity to quantify food webs within the main channel and five different, intact, side channels; ranging from channels that remained connected to the main channel at low flow to those reduced to floodplain ponds. Although we found that habitats within the floodplain had similar invertebrate prey production, these habitats hosted different local food webs. In the main channel, 95% of total prey consumption flowed to fishes that are not the target of proposed restoration. These fishes consumed 64% and 47% of the prey resources that were found to be important to fueling chinook and steelhead production in the main channel, respectively. Conversely, in side channels, a greater proportion of prey was consumed by anadromous salmonids. As a result, carrying capacity estimates based on food were 251% higher, on average, for anadromous salmonids in side channels than the main channel. However, salmon and steelhead production was generally well below estimated capacity in both the main and side channels, suggesting these habitats are under-seeded with respect to food, and that much larger populations could be supported. Overall, this study demonstrates that floodplain heterogeneity is

  10. MicroTrout: A comprehensive, genome-wide miRNA target prediction framework for rainbow trout, Oncorhynchus mykiss.

    PubMed

    Mennigen, Jan A; Zhang, Dapeng

    2016-12-01

    Rainbow trout represent an important teleost research model and aquaculture species. As such, rainbow trout are employed in diverse areas of biological research, including basic biological disciplines such as comparative physiology, toxicology, and, since rainbow trout have undergone both teleost- and salmonid-specific rounds of genome duplication, molecular evolution. In recent years, microRNAs (miRNAs, small non-protein coding RNAs) have emerged as important posttranscriptional regulators of gene expression in animals. Given the increasingly recognized importance of miRNAs as an additional layer in the regulation of gene expression and hence biological function, recent efforts using RNA- and genome sequencing approaches have resulted in the creation of several resources for the construction of a comprehensive repertoire of rainbow trout miRNAs and isomiRs (variant miRNA sequences that all appear to derive from the same gene but vary in sequence due to post-transcriptional processing). Importantly, through the recent publication of the rainbow trout genome (Berthelot et al., 2014), mRNA 3'UTR information has become available, allowing for the first time the genome-wide prediction of miRNA-target RNA relationships in this species. We here report the creation of the microtrout database, a comprehensive resource for rainbow trout miRNA and annotated 3'UTRs. The comprehensive database was used to implement an algorithm to predict genome-wide rainbow trout-specific miRNA-mRNA target relationships, generating an improved predictive framework over previously published approaches. This work will serve as a useful framework and sequence resource to experimentally address the role of miRNAs in several research areas using the rainbow trout model, examples of which are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Comparative susceptibility of Atlantic salmon, lake trout and rainbow trout to Myxobolus cerebralis in controlled laboratory exposures

    USGS Publications Warehouse

    Blazer, V.S.; Densmore, Christine L.; Schill, W.B.; Cartwright, Deborah D.; Page, S.J.

    2004-01-01

    The susceptibility of lake trout Salvelinus namaycush, rainbow trout Oncorhynchus mykiss and Atlantic salmon Salmo salar to Myxobolus cerebralis, the causative agent of whirling disease, was compared in controlled laboratory exposures. A total of 450 (225 for each dose) fry for each species were exposed to a low (200 spores per fish) or high (2000 spores per fish) dose of the infective triactinomyxon. At 22 wk post-exposure, 60 fish from each group, as well as controls for each species, were examined for clinical signs (whirling behavior, blacktail, deformed heads and skeletal deformities), microscopic lesions, and presence of spores. Rainbow trout were highly susceptible to infection, with 100% being positive for spores and with microscopic pathological changes in both exposure groups. Rainbow trout were the only species to show whirling behavior and blacktail. Atlantic salmon were less susceptible, with only 44 and 61% being positive for spores, respectively, in the low and high dose groups, while 68 and 75%, respectively, had microscopic pathology associated with cartilage damage. Rainbow trout heads contained mean spore concentrations of 2.2 (low dose) or 4.0 (high dose) ?? 106 spores g tissue-1. The means for positive Atlantic salmon (not including zero values) were 1.7 (low) and 7.4 (high) ?? 104 spores g tissue-1. Lake trout showed no clinical signs of infection, were negative for spores in both groups and showed no histopathological signs of M. cerebralis infection.

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

    USGS Publications Warehouse

    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.

  13. Determination of benzocaine in rainbow trout plasma

    USGS Publications Warehouse

    Bernardy, Jeffery A.; Coleman, K.S.; Stehly, G.R.; Gingerich, William H.

    1996-01-01

    A liquid chromatographic method is described for analysis of benzocaine (BZ), a proposed fish anesthetic, in rainbow trout plasma, Mean recoveries of BZ from plasma samples fortified at 44-10 100 ng/mL were 96-100%. The method detection limit is 10 ng/mL, and the limit of quantitation is 37 ng/mL. Acetylation of BZ occurs in whole blood after storage at room temperature (i.e., 21 degrees C) for 10 min. However, no acetylation of BZ was detected in plasma samples held at room temperature for 4 h, Mean method precision for plasma samples with incurred BZ residue is similar to that for fortified samples in the same concentration range (relative standard deviations of 0.9 and 1.2%, respectively).

  14. Glucosensing capacity of rainbow trout telencephalon.

    PubMed

    Otero-Rodiño, C; Rocha, A; Álvarez-Otero, R; Ceinos, R M; López-Patiño, M A; Míguez, J M; Cerdá-Reverter, J M; Soengas, J L

    2018-03-01

    To assess the hypothesis of glucosensing systems present in fish telencephalon, we first demonstrated in rainbow trout, by in situ hybridisation, the presence of glucokinase (GK). Then, we assessed the response of glucosensing markers in rainbow trout telencephalon 6 hours after i.c.v. treatment with glucose or 2-deoxyglucose (inducing glucoprivation). We evaluated the response of parameters related to the mechanisms dependent on GK, liver X receptor (LXR), mitochondrial activity, sweet taste receptor and sodium-glucose linked transporter 1 (SGLT-1). We also assessed mRNA abundance of neuropeptides involved in the metabolic control of food intake (agouti-related protein, neuropeptide Y, pro-opiomelanocortin, and cocaine- and amphetamine-related transcript), as well as the abundance and phosphorylation status of proteins possibly involved in linking glucosensing with neuropeptide expression, such as protein kinase B (AkT), AMP-activated protein kinase (AMPK), mechanistic target of rapamycin and cAMP response element-binding protein (CREB). The responses obtained support the presence in the telencephalon of a glucosensing mechanism based on GK and maybe one based on LXR, although they do not support the presence of mechanisms dependent on mitochondrial activity and SGLT-1. The mechanism based on sweet taste receptor responded to glucose but in a converse way to that characterised previously in the hypothalamus. In general, systems responded only to glucose but not to glucoprivation. Neuropeptides did not respond to glucose or glucoprivation. By contrast, the presence of glucose activates Akt and inhibits AMPK, CREB and forkhead box01. This is the first study in any vertebrate species in which the response to glucose of putative glucosensing mechanisms is demonstrated in the telencephalon. Their role might relate to processes other than homeostatic control of food intake, such as the hedonic and reward system. © 2018 British Society for Neuroendocrinology.

  15. Progress toward lake trout restoration in Lake Michigan

    USGS Publications Warehouse

    Holey, Mark E.; Rybicki, Ronald W.; Eck, Gary W.; Brown, Edward H.; Marsden, J. Ellen; Lavis, Dennis S.; Toneys, Michael L.; Trudeau, Tom N.; Horrall, Ross M.

    1995-01-01

    Progress toward lake trout restoration in Lake Michigan is described through 1993. Extinction of the native lake trout fishery by sea lamprey predation, augmented by exploitation and habitat destruction, resulted in an extensive stocking program of hatchery-reared lake trout that began in 1965. Sea lamprey abundance was effectively controlled using selective chemical toxicants. The initial stocking produced a measurable wild year class of lake trout by 1976 in Grand Traverse Bay, but failed to continue probably due to excessive exploitation. The overall lack of successful reproduction lakewide by the late 1970s led to the development and implementation in 1985 of a focused inter-agency lakewide restoration plan by a technical committee created through the Lake Committee structure of the Great Lakes Fishery Commission. Strategies implemented in 1985 by the plan included setting a 40% total mortality goal lakewide, creating two large refuges designed to encompass historically the most productive spawning habitat and protect trout stocked over their home range, evaluating several lake trout strains, and setting stocking priorities throughout the lake. Target levels for stocking in the 1985 Plan have never been reached, and are much less than the estimated lakewide recruitment of yearlings by the native lake trout stocks. Since 1985, over 90% of the available lake trout have been stocked over the best spawning habitat, and colonization of the historically productive offshore reefs has occurred. Concentrations of spawning lake trout large enough for successful reproduction, based on observations of successful hatchery and wild stocks, have developed at specific reefs. Continued lack of recruitment at these specific sites suggests that something other than stotk abundance has limited success. Poor survival of lake trout eggs, assumed to be related to contaminant burden, occurred in the late 1970s and early 1980s, but survival has since increased to equal survival in the

  16. Monitoring of Juvenile Yearling Chinook Salmon and Steelhead Survival and Passage at John Day Dam, Spring 2010

    SciTech Connect

    Weiland, Mark A.; Ploskey, Gene R.; Hughes, James S.

    2012-11-15

    The purpose of this study was to compare dam passage survival, at two spill treatment levels, of yearling Chinook salmon and steelhead smolts at John Day Dam during spring 2010. The two treatments were 30% and 40% spill out of total project discharge. Under the 2008 Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp), dam passage survival should be greater than or equal to 0.96 and estimated with a standard error (SE) less than or equal 0.015. The study also estimated forebay residence time, tailrace egress time, and spill passage efficiency (SPE), as required in the Columbia Basin Fishmore » Accords. However, by agreement among the stakeholders, this study was not an official BiOp compliance test because the long-term passage measures at John Day Dam have yet to be finalized and another year of spill-treatment testing was desired.« less

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

    USGS Publications Warehouse

    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.

  18. 48 CFR 227.7009-4 - Additional clauses-contracts providing for payment of a running royalty.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...-contracts providing for payment of a running royalty. 227.7009-4 Section 227.7009-4 Federal Acquisition... clauses—contracts providing for payment of a running royalty. The clauses set forth below are examples... desired to cover the subject matter thereof and the contract provides for payment of a running royalty. (a...

  19. 48 CFR 227.7009-4 - Additional clauses-contracts providing for payment of a running royalty.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...-contracts providing for payment of a running royalty. 227.7009-4 Section 227.7009-4 Federal Acquisition... clauses—contracts providing for payment of a running royalty. The clauses set forth below are examples... desired to cover the subject matter thereof and the contract provides for payment of a running royalty. (a...

  20. 48 CFR 227.7009-4 - Additional clauses-contracts providing for payment of a running royalty.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...-contracts providing for payment of a running royalty. 227.7009-4 Section 227.7009-4 Federal Acquisition... clauses—contracts providing for payment of a running royalty. The clauses set forth below are examples... desired to cover the subject matter thereof and the contract provides for payment of a running royalty. (a...

  1. 48 CFR 227.7009-4 - Additional clauses-contracts providing for payment of a running royalty.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...-contracts providing for payment of a running royalty. 227.7009-4 Section 227.7009-4 Federal Acquisition... clauses—contracts providing for payment of a running royalty. The clauses set forth below are examples... desired to cover the subject matter thereof and the contract provides for payment of a running royalty. (a...

  2. Sex-biased survivorship and differences in migration of wild steelhead (Oncorhynchus mykiss) smolts from two coastal Oregon rivers

    USGS Publications Warehouse

    Thompson, Neil F.; Leblanc, Camille A.; Romer, Jeremy D.; Schreck, Carl B.; Blouin, Michael S.; Noakes, David L. G.

    2016-01-01

    In salmonids with partial migration, females are more likely than males to undergo smoltification and migrate to the ocean (vs. maturing in freshwater). However, it is not known whether sex affects survivorship during smolt migration (from fresh water to entry into the ocean). We captured wild steelhead (Oncorhynchus mykiss) smolts in two coastal Oregon rivers (USA) and collected fin tissue samples for genetic sex determination (2009; N = 70 in the Alsea and N = 69 in the Nehalem, 2010; N = 25 in the Alsea). We implanted acoustic tags and monitored downstream migration and survival until entry in to the Pacific Ocean. Survival was defined as detection at an estuary/ocean transition array. We found no effect of sex on smolt survivorship in the Nehalem River in 2009, or in the Alsea River in 2010. However, males exhibited significantly lower survival than females in the Alsea River during 2009. Residency did not influence this result as an equal proportion of males and females did not reach the estuary entrance (11% of males, 9% of females). The sexes did not differ in timing or duration of migration, so those variables seem unlikely to explain sex-biased survivorship. Larger males had higher odds of survival than smaller males in 2009, but the body size of females did not affect survivorship. The difference in survivorship between years in the Alsea River could be due to flow conditions, which were higher in 2010 than in 2009. Our findings suggest that sex may affect steelhead smolt survival during migration, but that the difference in survivorship may be weak and not a strong factor influencing adult sex ratios.

  3. Sex biased survival and differences in migration of wild steelhead (Oncorhynchus mykiss) smolts from two coastal Oregon rivers

    USGS Publications Warehouse

    Thompson, Neil F.; Leblanc, Camille A.; Romer, Jeremy D.; Schreck, Carl B.; Blouin, Michael S.; Noakes, David L. G.

    2016-01-01

    In salmonids with partial migration, females are more likely than males to undergo smoltification and migrate to the ocean (vs. maturing in freshwater). However, it is not known whether sex affects survivorship during smolt migration (from fresh water to entry into the ocean). We captured wild steelhead (Oncorhynchus mykiss) smolts in two coastal Oregon rivers (USA) and collected fin tissue samples for genetic sex determination (2009; N = 70 in the Alsea and N = 69 in the Nehalem, 2010; N = 25 in the Alsea). We implanted acoustic tags and monitored downstream migration and survival until entry in to the Pacific Ocean. Survival was defined as detection at an estuary/ocean transition array. We found no effect of sex on smolt survivorship in the Nehalem River in 2009, or in the Alsea River in 2010. However, males exhibited significantly lower survival than females in the Alsea River during 2009. Residency did not influence this result as an equal proportion of males and females did not reach the estuary entrance (11% of males, 9% of females). The sexes did not differ in timing or duration of migration, so those variables seem unlikely to explain sex-biased survivorship. Larger males had higher odds of survival than smaller males in 2009, but the body size of females did not affect survivorship. The difference in survivorship between years in the Alsea River could be due to flow conditions, which were higher in 2010 than in 2009. Our findings suggest that sex may affect steelhead smolt survival during migration, but that the difference in survivorship may be weak and not a strong factor influencing adult sex ratios.

  4. Monitor and Evaluate the Genetic Characteristics of Supplemented Salmon and Steelhead, 2006-2007 Progress Report.

    SciTech Connect

    Berntson, Ewann; Waples, Robin S.; Moran, Paul

    2008-11-20

    This progress report offers a summary of genetic monitoring and evaluation research related to artificial propagation of Chinook salmon and steelhead in the Snake River basin. Our principal goal has been to characterize the relative (and net) reproductive success of hatchery fish spawning in the wild in multiple sub-basins. We address a critical uncertainty identified in essentially all tribal, state, and federal recovery planning efforts. Beyond simple description of those patterns of differential reproductive success, we seek to understand the biotic and abiotic factors that contribute to our observations, including genetic and environmental elements, and the real time effects ofmore » hatchery reform. We adopt two fundamentally different approaches that capture processes operating at different geographic scales. Our tier 2 design monitors changes in gene frequency through time in hatchery and wild populations. These studies monitor spatial and temporal genetic change over broad river basins and sub-basins. Tier 3 studies, by contrast, are able to construct pedigrees in naturally spawning populations that include hatchery and wild fish. We can then use actual matings to infer the fitness of hatchery versus wild individuals, based on the numbers of offspring we observe in our progeny samples. We get extraordinary detail from the tier 3 studies but only for a single river system. Thus, tier 2 studies provide breadth of information, whereas tier 3 studies offer unparalleled depth of insight for single discrete systems. We exceeded our goals in almost all areas for both tier 2 and tier 3 studies, and, where we did not, we offer an explanation of why, and what future action will be taken (Lessons Learned). All subcontracts were let as expected, providing smolt trapping, tissue sampling, genotyping, and analysis. Our inter-laboratory standardization efforts with tribal, state, and federal agencies were highly successful in this period. These standardization

  5. IN VIVO MEASUREMENT OF PHENYLGLUCUCURONIDE IN RAINBOW TROUT BY ON-LINE INJECTION MICRODIALYSIS

    EPA Science Inventory

    Phenylglucuronide (PG) was measured in vivo in arterial blood of rainbow trout using on-line injection microdialysis. A microdialysis probe was surgically implanted in the dorsal aorta of spinally-transected trout. The trout were dosed continuously with PG for 24 h using a ventra...

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

    EPA Science Inventory

    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...

  7. Spawning and movement behavior of migratory coastal cutthroat trout on the western Copper River delta, Alaska.

    Treesearch

    D.A. Saiget; M.R. Sloat; Reeves. G.H.

    2007-01-01

    We studied the movement patterns of migratory coastal cutthroat trout Oncorhynchus clarkii clarkii in the western Copper River delta, Alaska, near the northern extent of the subspecies' distribution. Life history information for coastal cutthroat trout is scarce within this region. Movement of coastal cutthroat trout was monitored from 1994 to...

  8. Estimate of net trophic transfer efficiency of PCBs to Lake Michigan lake trout from their prey

    USGS Publications Warehouse

    Madenjian, Charles P.; Hesselberg, Robert J.; DeSorcie, Timothy J.; Schmidt, Larry J.; Stedman, Ralph M.; Quintal, Richard T.; Begnoche, Linda J.; Passino-Reader, Dora R.

    1998-01-01

    Most of the polychlorinated biphenyl (PCB) body burden accumulated by lake trout (Salvelinus namaycush) from the Laurentian Great Lakes is from their food. We used diet information, PCB determinations in both lake trout and their prey, and bioenergetics modeling to estimate the efficiency with which Lake Michigan lake trout retain PCBs from their food. Our estimates were the most reliable estimates to date because (a) the lake trout and prey fish sampled during our study were all from the same vicinity of the lake, (b) detailed measurements were made on the PCB concentrations of both lake trout and prey fish over wide ranges in fish size, and (c) lake trout diet was analyzed in detail over a wide range of lake trout size. Our estimates of net trophic transfer efficiency of PCBs to lake trout from their prey averaged from 0.73 to 0.89 for lake trout between the ages of 5 and 10 years old. There was no evidence of an upward or downward trend in our estimates of net trophic transfer efficiency for lake trout between the ages of 5 and 10 years old, and therefore this efficiency appeared to be constant over the duration of the lake trout's adult life in the lake. On the basis of our estimtes, lake trout retained 80% of the PCBs that are contained within their food.

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

    Treesearch

    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...

  10. The use of hoop nets seeded with mature brook trout to capture conspecifics

    Treesearch

    James A. Lamansky; Ernest R. Keeley; Michael K. Young; Kevin A. Meyer

    2009-01-01

    The brook trout Salvelinus fontinalis, a native of eastern North America, is considered an invasive species in the western United States because it has been implicated in the decline of many native trout species there. Current methods for controlling brook trout are usually time-consuming and expensive and are sometimes harmful to nontarget species....

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

    USGS Publications Warehouse

    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.

  12. Movements of nonnative brook trout in relation to stream channel slope

    Treesearch

    Susan B. Adams; Christopher A. Frissell; Bruce E. Rieman

    2000-01-01

    Abstract.We provide new insights on the ability of naturalized brook trout Salvelinus fontinalis to ascend steep, headwater streams in the western USA. We tested hypotheses that upstream movements by brook trout are limited or absent in reaches of steep streams and are more prevalent and longer in gradually sloping streams. We compared brook trout...

  13. Global climate change and fragmentation of native brook trout distribution in the southern Appalachian Mountains

    Treesearch

    Patricia A. Flebbe

    1997-01-01

    Current distributions of native brook trout (Salvelinus fontinalis) in the Southern Appalachians are restricted to upper elevations by multiple factors, including habitat requirements, introduced rainbow (Oncorhynchus mykiss) and brown (Salmo trutta) trout, and other human activities. Present-day distribution of brook trout habitat is already fragmented. Increased...

  14. Introgression and susceptibility to disease in a wild population of rainbow trout

    USGS Publications Warehouse

    Currens, K.P.; Hemmingsen, A.R.; French, R.A.; Buchanan, D.V.; Schreck, C.B.; Li, H.W.

    1997-01-01

    We examined susceptibility of wild rainbow trout Oncorhynchus mykiss from the Metolius River, a tributary of the Deschutes River, Oregon, to genetic introgression and ceratomyxosis as a result of stocking nonnative hatchery rainbow trout. Ceratomyxa shasta, an enzootic myxosporean parasite that can be lethal to nonnative hatchery rainbow trout, might have been limiting the interbreeding of hatchery and wild rainbow trout in the river. However, rainbow trout from the Metolius River had allozyme frequencies intermediate between those of wild and hatchery fish at LDH-B2* and sSOD-1*, two diagnostic genetic loci that allow the inland subspecies of rainbow trout to be distinguished from hatchery strains of coastal origin. They also had notable frequencies of ADA-1*85, an allele documented in hatchery rainbow trout but rarely seen in wild populations. We also found that rainbow trout in the Metolius River averaged 138.9 scales in the lateral series, intermediate between the counts for 9 coastal or nonnative hatchery populations, which always had fewer than 140 scales, and 10 inland populations, which always had more than 140 scales. Disease challenges revealed that rainbow trout from the Metolius River had much greater susceptibility to C. shasta than rainbow trout from the Deschutes River, which have genetic resistance to the lethal disease. Based on these data, we concluded that introgression with nonnative hatchery rainbow trout has reduced the abilities of wild rainbow trout in the Metolius River to survive when conditions for ceratomyxosis infection occur.

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

    USGS Publications Warehouse

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

    2015-01-01

    Our results indicate that YOY abundance is a key driver of brook trout population dynamics that is mediated by seasonal weather patterns. A reliable assessment of climate change impacts on brook trout needs to account for how alternations in seasonal weather patterns impact YOY abundance and how such relationships may differ across the range of brook trout distribution.

  16. Brook trout movement within a high-elevation watershed: Consequences for watershed restoration

    Treesearch

    Jeff L. Hansbarger; J. Todd Petty; Patricia M. Mazik

    2010-01-01

    We used radio-telemetry to quantify brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta) movements in the Shavers Fork of the Cheat River, West Virginia, and an adjacent second-order tributary (Rocky Run). Our objectives were to quantify the overall rate of trout movement, assess spatial and temporal variation in...

  17. Patterns and dynamics of vegetation recovery following grazing cessation in the California golden trout habitat

    Treesearch

    Sébastien Nusslé; Kathleen R. Matthews; Stephanie M. Carlson

    2017-01-01

    In 1978, the Golden Trout Wilderness area was established to protect the California golden trout (Oncorhynchus mykiss aguabonita)—a vulnerable subspecies of the rainbow trout that is endemic to California—and its habitat, which is currently restricted to a few streams within high-elevation meadows in the Sierra Nevada Mountain Range....

  18. Winter feeding success of stream trout under different streamflow and turbidity conditions

    Treesearch

    Jason L. White; Bret C. Harvey

    2007-01-01

    To investigate the relationship between turbidity and trout feeding success in natural systems, we sampled the stomach contents of resident rainbow trout Oncorhynchus mykiss and coastal cutthroat trout O. clarkii clarkii under different streamflow and turbidity conditions during winter in two northwestern California streams (total sample size¼161). Feeding success...

  19. Cool Water Formation and Trout Habitat Use in a Deep Pool in the Sierra Nevada, California

    Treesearch

    KATHLEEN R. MATTHEWS; NEIL H. BERG; AZUMA DAVID L.

    1994-01-01

    We documented temperature stratification in a deep bedrock pool in the North Fork of the American River, described the diel movement of rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta. and determined whether these trout used cooler portions of the pool.From July 30 to October 10, 1992, the main study pool and an adjacent pool were stratified(temperature...

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

    USGS Publications Warehouse

    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.

  1. Rainbow trout responses to water temperature and dissolved oxygen stress in two southern California stream pools

    Treesearch

    K.R. Matthews; N.H. Berg

    1997-01-01

    Habitat use by rainbow trout Oncorhynchus mykiss is described for a southern California stream where the summer water temperatures typically exceed the lethal limits for trout (>25) C). During August 1994, water temperature, dissolved oxygen (DO), and trout distribution were monitored in two adjacent pools in Sespe Creek, Ventura County, where summer water...

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

    Treesearch

    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...

  3. Evaluation of an Unsuccessful Brook Trout Electrofishing Removal Project in a Small Rocky Mountain Stream.

    SciTech Connect

    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 brookmore » 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.« less

  4. Stream pH as an abiotic gradient influencing distributions of trout in Pennsylvania streams

    USGS Publications Warehouse

    Kocovsky, P.M.; Carline, R.F.

    2005-01-01

    Elevation and stream slope are abiotic gradients that limit upstream distributions of brook trout Salvelinus fontinalis and brown trout Salmo trutta in streams. We sought to determine whether another abiotic gradient, base-flow pH, may also affect distributions of these two species in eastern North America streams. We used historical data from the Pennsylvania Fish and Boat Commission's fisheries management database to explore the effects of reach elevation, slope, and base-flow pH on distributional limits to brook trout and brown trout in Pennsylvania streams in the Appalachian Plateaus and Ridge and Valley physiographic provinces. Discriminant function analysis (DFA) was used to calculate a canonical axis that separated allopatric brook trout populations from allopatric brown trout populations and allowed us to assess which of the three independent variables were important gradients along which communities graded from allopatric brook trout to allopatric brown trout. Canonical structure coefficients from DFA indicated that in both physiographic provinces, stream base-flow pH and slope were important factors in distributional limits; elevation was also an important factor in the Ridge and Valley Province but not the Appalachian Plateaus Province. Graphs of each variable against the proportion of brook trout in a community also identified apparent zones of allopatry for both species on the basis of pH and stream slope. We hypothesize that pH-mediated interspecific competition that favors brook trout in competition with brown trout at lower pH is the most plausible mechanism for segregation of these two species along pH gradients. Our discovery that trout distributions in Pennsylvania are related to stream base-flow pH has important implications for brook trout conservation in acidified regions. Carefully designed laboratory and field studies will be required to test our hypothesis and elucidate the mechanisms responsible for the partitioning of brook trout and

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

    PubMed

    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).

  6. Acute and chronic toxicity studies with monochlorobenzene in rainbow trout

    USGS Publications Warehouse

    Dahlich, G.M.; Larson, R.E.; Gingerich, W.H.

    1982-01-01

    The toxicity of monochlorobenzene (CB) was investigated in rainbow trout following acute intraperitoneal (i.p.) administration and chronic exposure via the water in a continuously flowing system for 15 or 30 days. In the acute study overt toxicity and hepatotoxicity were monitored over a 96-h time period. Variables measured to assess toxicity included weight changes, liver weight to body weight ratios, behavioral changes, alanine aminotransferase activity (GPT), sulfobromophthalein (BSP) retention, total plasma protein concentration and liver histopathology. In the chronic study the same measures of toxicity were followed as well as food consumption and alkaline phosphatase (AP) activity. Upon acute i.p. exposure the toxicant (9.8 mmol/kg) caused behavioral changes in the fish which were consistent with the known anesthetic properties of CB in mammals. Elevations in BSP retention and GPT activity, and histopathology indicated that CB was hepatotoxic in fish. The LC50 of CB in trout exposed via the water for 96 h was 4.7 mg/l. Chronic exposure of trout to 2 or 3 mg/l CB resulted in similar behavioral changes as seen in the acute study. Liver toxicity was evident from elevations in GPT activity. BSP retention and AP activity appeared to be affected by the nutritional status of the trout as much as by the CB treatment. After 30 days of exposure to 3 mg/l CB, trout appeared to have developed some tolerance to the toxic effects.

  7. Predicting presence and absence of trout (Salmo trutta) in Iran.

    PubMed

    Mostafavi, Hossein; Pletterbauer, Florian; Coad, Brian W; Mahini, Abdolrassoul Salman; Schinegger, Rafaela; Unfer, Günther; Trautwein, Clemens; Schmutz, Stefan

    2014-03-01

    Species distribution modelling, as a central issue in freshwater ecology, is an important tool for conservation and management of aquatic ecosystems. The brown trout ( Salmo trutta ) is a sensitive species which reacts to habitat changes induced by human impacts. Therefore, the identification of suitable habitats is essential. This study explores the potential distribution of brown trout by a species distribution modelling approach for Iran. Furthermore, modelling results are compared to the distribution described in the literature. Areas outside the currently known distribution which may offer potential habitats for brown trout are identified. The species distribution modelling was based on five different modelling techniques: Generalised Linear Model, Generalised Additive Model, Generalised Boosting Model, Classification Tree Analysis and Random Forests, which are finally summarised in an ensemble forecasting approach. We considered four environmental descriptors at the local scale (slope, bankfull width, wetted width, and elevation) and three climatic parameters (mean air temperature, range of air temperature and annual precipitation) which were extracted on three different spatial extents (1/5/10 km). The performance of all models was excellent (≥0.8) according to the TSS (True Skill Statistic) criterion. Slope, mean and range of air temperature were the most important variables in predicting brown trout occurrence. Presented results deepen the knowledge about distribution patterns of brown trout in Iran. Moreover, this study gives a basic background for the future development of assessment methods for riverine ecosystems in Iran.

  8. Cortisol kinetics and fluid distribution in brook trout (Salvelinus fontinalis).

    PubMed

    Nichols, D J; Weisbart, M; Quinn, J

    1985-10-01

    Cortisol kinetics were examined in brook trout (Salvelinus fontinalis) to assess possible relationships with body fluid distribution during acclimation to sea water (SW). The disappearance curve of [3H]cortisol in plasma, after a bolus injection, was analysed by compartmental analysis using a three-pool mammillary model. The results indicated that only approximately 10% of the total exchangeable cortisol was located in the plasma pool. Over 75% of the total cortisol was associated with a large slowly exchanging pool and the remaining cortisol was located in a second extravascular tissue pool which was in rapid exchange with the plasma pool. Two days after transfer of trout from fresh water to SW, when plasma chloride concentration was at a new steady state, body weight, intracellular fluid volume, haematocrit and inulin clearance rate were lowered but plasma, blood and extracellular volumes were unaltered. Cortisol plasma clearance rate was unaltered but plasma cortisol concentration, cortisol secretion rate, total cortisol pool size and interpool transport rates were increased. These results are consistent with an acute role for cortisol in SW adaptation of brook trout. The fraction of the total cortisol cleared was smaller and the average time that cortisol spent in the tissue pools was slightly longer in trout after transfer to SW, possibly reflecting altered fluid dynamics. The fractional disappearance rate was larger at higher plasma cortisol concentrations in the SW trout. This relationship is compatible with the hypothesis that cortisol protein binding protects cortisol from metabolism.

  9. Spatial Ecological Processes and Local Factors Predict the Distribution and Abundance of Spawning by Steelhead (Oncorhynchus mykiss) across a Complex Riverscape

    PubMed Central

    Falke, Jeffrey A.; Dunham, Jason B.; Jordan, Christopher E.; McNyset, Kristina M.; Reeves, Gordon H.

    2013-01-01

    Processes that influence habitat selection in landscapes involve the interaction of habitat composition and configuration and are particularly important for species with complex life cycles. We assessed the relative influence of landscape spatial processes and local habitat characteristics on patterns in the distribution and abundance of spawning steelhead (Oncorhynchus mykiss), a threatened salmonid fish, across ∼15,000 stream km in the John Day River basin, Oregon, USA. We used hurdle regression and a multi-model information theoretic approach to identify the relative importance of covariates representing key aspects of the steelhead life cycle (e.g., site access, spawning habitat quality, juvenile survival) at two spatial scales: within 2-km long survey reaches (local sites) and ecological neighborhoods (5 km) surrounding the local sites. Based on Akaike’s Information Criterion, models that included covariates describing ecological neighborhoods provided the best description of the distribution and abundance of steelhead spawning given the data. Among these covariates, our representation of offspring survival (growing-season-degree-days, °C) had the strongest effect size (7x) relative to other predictors. Predictive performances of model-averaged composite and neighborhood-only models were better than a site-only model based on both occurrence (percentage of sites correctly classified = 0.80±0.03 SD, 0.78±0.02 vs. 0.62±0.05, respectively) and counts (root mean square error = 3.37, 3.93 vs. 5.57, respectively). The importance of both temperature and stream flow for steelhead spawning suggest this species may be highly sensitive to impacts of land and water uses, and to projected climate impacts in the region and that landscape context, complementation, and connectivity will drive how this species responds to future environments. PMID:24265762

  10. Spatial ecological processes and local factors predict the distribution and abundance of spawning by steelhead (Oncorhynchus mykiss) across a complex riverscape

    USGS Publications Warehouse

    Falke, Jeffrey A.; Dunham, Jason B.; Jordan, Christopher E.; McNyset, Kris M.; Reeves, Gordon H.

    2013-01-01

    Processes that influence habitat selection in landscapes involve the interaction of habitat composition and configuration and are particularly important for species with complex life cycles. We assessed the relative influence of landscape spatial processes and local habitat characteristics on patterns in the distribution and abundance of spawning steelhead (Oncorhynchus mykiss), a threatened salmonid fish, across ~15,000 stream km in the John Day River basin, Oregon, USA. We used hurdle regression and a multi-model information theoretic approach to identify the relative importance of covariates representing key aspects of the steelhead life cycle (e.g., site access, spawning habitat quality, juvenile survival) at two spatial scales: within 2-km long survey reaches (local sites) and ecological neighborhoods (5 km) surrounding the local sites. Based on Akaike’s Information Criterion, models that included covariates describing ecological neighborhoods provided the best description of the distribution and abundance of steelhead spawning given the data. Among these covariates, our representation of offspring survival (growing-season-degree-days, °C) had the strongest effect size (7x) relative to other predictors. Predictive performances of model-averaged composite and neighborhood-only models were better than a site-only model based on both occurrence (percentage of sites correctly classified = 0.80±0.03 SD, 0.78±0.02 vs. 0.62±0.05, respectively) and counts (root mean square error = 3.37, 3.93 vs. 5.57, respectively). The importance of both temperature and stream flow for steelhead spawning suggest this species may be highly sensitive to impacts of land and water uses, and to projected climate impacts in the region and that landscape context, complementation, and connectivity will drive how this species responds to future environments.

  11. Size-selective mortality of steelhead during freshwater and marine life stages related to freshwater growth in the Skagit River, Washington

    USGS Publications Warehouse

    Thompson, Jamie N.; Beauchamp, David A.

    2014-01-01

    We evaluated freshwater growth and survival from juvenile (ages 0–3) to smolt (ages 1–5) and adult stages in wild steelhead Oncorhynchus mykiss sampled in different precipitation zones of the Skagit River basin, Washington. Our objectives were to determine whether significant size-selective mortality (SSM) in steelhead could be detected between early and later freshwater stages and between each of these freshwater stages and returning adults and, if so, how SSM varied between these life stages and mixed and snow precipitation zones. Scale-based size-at-annulus comparisons indicated that steelhead in the snow zone were significantly larger at annulus 1 than those in the mixed rain–snow zone. Size at annuli 2 and 3 did not differ between precipitation zones, and we found no precipitation zone × life stage interaction effect on size at annulus. Significant freshwater and marine SSM was evident between the juvenile and adult samples at annulus 1 and between each life stage at annuli 2 and 3. Rapid growth between the final freshwater annulus and the smolt migration did not improve survival to adulthood; rather, it appears that survival in the marine environment may be driven by an overall higher growth rate set earlier in life, which results in a larger size at smolt migration. Efforts for recovery of threatened Puget Sound steelhead could benefit by considering that SSM between freshwater and marine life stages can be partially attributed to growth attained in freshwater habitats and by identifying those factors that limit growth during early life stages.

  12. Refrigeration of rainbow trout gametes and embryos.

    PubMed

    Babiak, Igor; Dabrowski, Konrad

    2003-12-01

    Prolonged access to early embryos composed of undifferentiated, totipotent blastomeres is desirable in situations when multiple collections of gametes are not possible. The objective of the present study is to examine whether the refrigeration of rainbow trout Oncorhynchus mykiss gametes and early embryos would be a suitable, reliable, and efficient tool for prolonging the availability of early developmental stages up to the advanced blastula stage. The study was conducted continuously during fall, winter, and spring spawning seasons. In all, more than 500 experimental variants were performed involving individual samples from 26 females and 33 males derived from three strains. These strains represented three possible circumstances. In optimal one, gametes from good quality donors were obtained soon after ovulation. In the two non-optimal sources, either donors were of poor genetic quality or gametes were collected from a distant location and transported as unfertilized gametes. A highly significant effect of variability of individual sample quality on efficiency of gamete and embryo refrigeration was revealed. The source of gametes significantly affected viability of refrigerated oocytes and embryos, but not spermatozoa. On average, oocytes from optimal source retained full fertilization viability for seven days of chilled storage, significantly longer than from non-optimal sources. Spermatozoa, regardless of storage method, retained full fertilization ability for the first week of storage. Refrigeration of embryos at 1.4+/-0.4 degrees C significantly slowed the development. Two- week-old embryos were still in blastula stage. Average survival rate of embryos refrigerated for 10 days and then transferred to regular incubation temperatures of 9-14 degrees C was 92% in optimal and 51 and 71% in non-optimal source variants. No effect of gamete and embryo refrigeration on the occurrence of developmental abnormalities was observed. Cumulative refrigeration of oocytes and

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

    USGS Publications Warehouse

    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.

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

    USGS Publications Warehouse

    Eschmeyer, Paul H.; Phillips, Arthur M.

    1965-01-01

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

  15. Ultrastructural changes in the hepatocytes of juvenile rainbow trout and mature brown trout exposed to copper or zinc

    USGS Publications Warehouse

    Leland, H.V.

    1983-01-01

    Morphological changes in hepatocytes of mature brown trout (Salmo trutta Linnaeus) and juvenile rainbow trout (Salmo gairdneri Richardson), accompanying chronic exposures to copper and zinc, were examined by transmission electron microscopy. At a concentration of copper not inhibitory to the final stages of gonadal development or spawning of brown trout, structural alterations included contraction of mitochondria and a tendency for nuclei to be slightly enlarged. Concentrations of copper or zinc lethal to a small fraction (10% and 4%, respectively) of a population of juvenile rainbow trout exposed for 42 d during larval and early juvenile development caused hepatocyte changes in survivors indicative of a reduction in ability to maintain intracellular water and cation balance and possible intranuclear metal sequestering. Specific structural alterations included increased vesiculation of rough endoplasmic reticulum, an increase in the abundance of electron-dense particles in the nucleus, increases in the numbers of multilaminar and globular inclusions, pooling of glycogen, increased autophagocytic activity and an increase in the number of necrotic cells. At advanced stages of toxicosis (concentrations of copper or zinc lethal to approximately 50% of the juveniles exposed for 42 d during development), loss in integrity of mitochondrial membranes, rupturing of plasma and nuclear membranes, separation of granular and fibrillar nuclear components, fragmentation of endoplasmic reticulum, and extensive autophagic vacuolization were significant features of hepatocytes of surviving juvenile rainbow trout. ?? 1983.

  16. Stocking and hooking mortality of planted rainbow trout in Jocassee Reservoir, South Carolina

    USGS Publications Warehouse

    Barwick, D. Hugh

    1985-01-01

    Attempts to establish a 'put-grow-and-take' fishery for rainbow trout (Salmo gairdneri) in Jocassee Reservoir, South Carolina failed despite plantings of 200,000 fish in 1972-1979 because few of the stocked fish survived to legal size. At the same time, a fishery for brown trout (Salmo trutta) was established successfully by planting far fewer fish. Experiments were conducted to determine if stress at stocking and injuries and stress associated with catch and release of fish by shoreline anglers were responsible for the poor survival of rainbow trout. Only 1 of the 606 rainbow trout stocked in floating wire cages anchored in the reservoir died during the first 3 days, and fewer rainbow trout than brown trout died as a result of catch-and-release fishing during the first 11 days after stocking. Thus, these factors were not responsible for the lack of success in establishing a rainbow trout fishery in this reservoir.

  17. Lake trout demographics in relation to burbot and coregonine populations in the Algonquin Highlands, Ontario

    USGS Publications Warehouse

    Carl, L.M.

    2008-01-01

    The objective of the study was to test the hypothesis that lake trout populations change in relation to cisco, lake whitefish, round whitefish and burbot populations in lakes in the Algonquin Highlands region of Ontario. Lake trout population change is greatest where cisco and lake whitefish are present. Lake trout populations in lakes without either coregonine tend to have small adults and many juveniles. Where cisco or lake whitefish are present, adult lake trout are large, juvenile abundance is low, and the stock-recruit relationship appears to be uncoupled likely due to a larval bottleneck. Lake trout populations in these lakes may be sensitive to overfishing and recruitment failure. Lake trout populations do not appear to change in relation to round whitefish. There appears to be an indirect positive change on juvenile lake trout abundance through reductions in the density of benthic coregonines in the presence of large, hypolimnetic burbot. ?? 2007 Springer Science+Business Media B.V.

  18. Factors affecting feeding behavior and survival of juvenile lake trout in the Great Lakes

    USGS Publications Warehouse

    Savino, Jacqueline F.; Henry, Mary G.; Kincaid, Harold L.

    1993-01-01

    We explored the importance of experience with feeding on live prey, of cataracts, of strain, and of maternally transferred contaminants for the feeding rate and predator avoidance behavior of young lake trout Salvelinus namaycush. Hatchery-reared and feral juvenile lake trout were tested separately as predators on lake trout fry in tanks with artificial cobble reefs. Feral fish captured more prey per day and more prey per strike than did hatchery lake trout. The predatory performance of hatchery and feral fish did not improve significantly with experience. Feeding rates did not differ between lake trout with unilateral cataracts and normal-eyed fish, but significantly diminished for lake trout with bilateral cataracts. Neither strain nor contaminant background affected the ability of fry to feed or to avoid predators. Of the factors studied, previous experience with live food under natural conditions (i.e., the experience of feral fish) was the most important factor affecting feeding behavior of young lake trout.

  19. Crayfish (Orconectes virilis) feeding on young lake trout (Salvelinus namaycush): effect of rock size

    USGS Publications Warehouse

    Savino, Jacqueline F.; Miller, John E.

    1991-01-01

    In laboratory studies, we quantified predation rates of crayfish (Orconectes virilis) on the eggs and sac fry of lake trout (Salvelinus namaycush) and a surrogate species, rainbow trout (Oncorhynchus mvkiss), dispersed among different sized substrates (bare bottom, gravel, cobble, large rocks). Predation was most severe when no rocks were present. Feeding rate then decreased as the substrate changed from large rocks to cobble to gravel. Crayfish predation rate did not change with prey type—rainbow trout and lake trout eggs or sac fry. Crayfish foraging in large tanks containing cobble averaged about two eggs or sac fry per day. In most instances, crayfish would have little impact on lake trout egg survival. Only in lake trout spawning grounds with relatively low egg densities, large crayfish populations, and cobble or large rock substrate, would crayfish be expected to have some impact on lake trout egg survival.

  20. Hybridization and cytonuclear associations among native westslope cutthroat trout, introduced rainbow trout, and their hybrids within the Stehekin River drainage, North Cascades National Park

    USGS Publications Warehouse

    Ostberg, C.O.; Rodriguez, R.J.

    2006-01-01

    Historic introductions of nonnative rainbow trout Oncorhynchus mykiss into the native habitats of cutthroat trout O. clarkii have impacted cutthroat trout populations through introgressive hybridization, creating challenges and concerns for cutthroat trout conservation. We examined the effects of rainbow trout introductions on the native westslope cutthroat trout O. c. lewisii within the Stehekin River drainage, North Cascades National Park, Washington, by analyzing 1,763 salmonid DNA samples from 18 locations with nine diagnostic nuclear DNA markers and one diagnostic mitochondrial DNA (mtDNA) marker. Pure westslope cutthroat trout populations only occurred above upstream migration barriers in the Stehekin River and Park Creek. Two categories of rainbow trout admixture were observed: (1) less than 10% within the Stehekin River drainage above the Bridge Creek confluence and the middle and upper Bridge Creek drainage and (2) greater than 30% within the Stehekin River below the Bridge Creek confluence and in lower Bridge Creek. Hybrid indices and multilocus genotypes revealed an absence of rainbow trout and reduced hybrid diversity within the Stehekin River above the Bridge Creek confluence relative to hybrid diversity in the Stehekin River below the confluence and within lower Bridge Creek. Cytonuclear disequilibrium statistics revealed assortative mating between westslope cutthroat and rainbow trout but not among hybrids within the same locations. This suggests that a randomly mating hybrid swarm does not currently exist. However, continual migration of parental genotypes into the study location could also create significant cytonuclear disequilibria. The Stehekin River represents a novel and unique example of a dynamic hybridization zone where the invasion of rainbow trout alleles into the Stehekin River westslope cutthroat trout population above the Bridge Creek confluence appears to be impeded, suggesting that divergent ecological or evolutionary mechanisms

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

    USGS Publications Warehouse

    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.

  2. Comparison of the macroparasite communities of wild and stocked brown trout (Salmo trutta L.) in the west of Ireland.

    PubMed

    Byrne, C J; Holland, C V; Poole, R; Kennedy, C R

    2002-04-01

    The aim of the present study was to compare the helminth infra and component communities of wild and stocked brown trout in Lough Feeagh, in the west of Ireland, and also to examine the establishment and development of helminth communities in stocked brown trout. Fish were sampled in May, August and November 1997 and 1998 and an additional sample of wild brown trout was examined in April 1997. In total 217 wild trout and 122 stocked trout were examined. The acanthocephalans Acanthocephalus clavula and Pomphorhynchus laevis were the first parasite species to infect stocked trout in May 1997. In May 1998 both acanthocephalan species along with the trout specialists Eubothrium crassum and Crepidostomumfarionis were the first to infect trout. Mean species richness values for stocked trout increased from May to November, in 1997 and 1998. For wild trout, mean species richness values increased from April to November, in 1997 and decreased from May to November in 1998. The parasite communities of wild trout were richer than those of stocked trout in May of both years. In August the parasite communities recorded for wild and stocked trout were similar in terms of the number of species present but differed in terms of structure, and in November the parasite communities of stocked trout were richer than those of wild trout.

  3. Gyrodactylid Ectoparasites in a Population of Rainbow Trout (Oncorhynchus mykiss)

    PubMed Central

    Garcia, Rachel L; Hansen, Adam G; Chan, Maia M; Sanders, George E

    2014-01-01

    A colony of rainbow trout (Oncorhynchus mykiss) in a decentralized aquatic animal facility was noted to have an increase in morbidity and mortality (from 4 or 5 fish each month to 3 or 4 fish daily) approximately 2 wk after experimental procedures began. The primary clinical signs were erratic swimming behavior and ‘flashing’ of fish against surfaces within housing enclosures. Moribund and normal rainbow trout were presented alive for diagnostic evaluation; samples of water from housing enclosures were provided for water quality assessment. The trout were determined to be infected with gyrodactylids, a common monogenean ectoparasite of the skin and gills in both marine and freshwater fish. This case report describes the diagnosis, pathology, and treatment of gyrodactylids and husbandry modifications associated with the resolution of this clinical aquatic-animal case. PMID:24411786

  4. Comparative bioenergetics modeling of two Lake Trout morphotypes

    USGS Publications Warehouse

    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

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

    PubMed

    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

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

    PubMed Central

    2013-01-01

    Background 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. Results 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. Conclusions Chromosome rearrangements suppressed recombination in the hybrids. This result

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

    USGS Publications Warehouse

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

    2009-01-01

    Efforts to restore self-sustaining lake trout (Salvelinus namaycush) populations in the Laurentian Great Lakes have had widespread success in Lake Superior; but in other Great Lakes, populations of lake trout are maintained by stocking. Recruitment bottlenecks may be present at a number of stages of the reproduction process. To study eggs and fry, it is necessary to identify spawning locations, which is difficult in deep water. Acoustic sampling can be used to rapidly locate aggregations of fish (like spawning lake trout), describe their distribution, and estimate their abundance. To assess these capabilities for application to lake trout, we conducted an acoustic survey covering 22 km2 at Sheboygan Reef, a deep reef (<40 m summit) in southern Lake Michigan during fall 2005. Data collected with remotely operated vehicles (ROV) confirmed that fish were large lake trout, that lake trout were 1–2 m above bottom, and that spawning took place over specific habitat. Lake trout density exhibited a high degree of spatial structure (autocorrelation) up to a range of ~190 m, and highest lake trout and egg densities occurred over rough substrates (rubble and cobble) at the shallowest depths sampled (36–42 m). Mean lake trout density in the area surveyed (~2190 ha) was 5.8 fish/ha and the area surveyed contained an estimated 9500–16,000 large lake trout. Spatial aggregation in lake trout densities, similarity of depths and substrates at which high lake trout and egg densities occurred, and relatively low uncertainty in the lake trout density estimate indicate that acoustic sampling can be a useful complement to other sampling tools used in lake trout restoration research.

  8. Trout piscivory in the Colorado River, Grand Canyon: Effects of turbidity, temperature, and fish prey availability

    USGS Publications Warehouse

    Yard, Michael D.; Coggins,, Lewis G.; Baxter, Colden V.; Bennett, Glenn E.; Korman, Josh

    2011-01-01

    Introductions of nonnative salmonids, such as rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta, have affected native fishes worldwide in unforeseen and undesirable ways. Predation and other interactions with nonnative rainbow trout and brown trout have been hypothesized as contributing to the decline of native fishes (including the endangered humpback chub Gila cypha) in the Colorado River, Grand Canyon. A multiyear study was conducted to remove nonnative fish from a 15-km segment of the Colorado River near the Little Colorado River confluence. We evaluated how sediment, temperature, fish prey availability, and predator abundance influenced the incidence of piscivory (IP) by nonnative salmonids. Study objectives were addressed through spatial (upstream and downstream of the Little Colorado River confluence) and temporal (seasonal and annual) comparisons of prey availability and predator abundance. Data were then evaluated by modeling the quantity of fish prey ingested by trout during the first 2 years (2003–2004) of the mechanical removal period. Field effort resulted in the capture of 20,000 nonnative fish, of which 90% were salmonids. Results indicated that the brown trout IP was higher (8–70%) than the rainbow trout IP (0.5–3.3%); however, rainbow trout were 50 times more abundant than brown trout in the study area. We estimated that during the study period, over 30,000 fish (native and nonnative species combined) were consumed by rainbow trout (21,641 fish) and brown trout (11,797 fish). On average, rainbow trout and brown trout ingested 85% more native fish than nonnative fish in spite of the fact that native fish constituted less than 30% of the small fish available in the study area. Turbidity may mediate piscivory directly by reducing prey detection, but this effect was not apparent in our data, as rainbow trout IP was greater when suspended sediment levels (range = 5.9–20,000 mg/L) were higher.

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

    USGS Publications Warehouse

    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 (<250 mm TL, 250–400 mm TL, >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.

  10. Residues of oxytetracycline in cultured rainbow trout.

    PubMed

    Sharafati-Chaleshtori, R; Mardani, G; Rafieian-Kopaei, M; Sharafati-Chaleshtori, A; Drees, F

    2013-11-01

    Nowadays, antibiotics are widely used in aquatic animals to control and treatment of infections or as food supplement for growth increase and animal output. With increasing use of veterinary drugs in food production, there is global consideration about the consumption of antimicrobial residues in aquatic foods and their effects on human health. This study was aimed to evaluate the Oxytetracycline (OTC) residues in Rainbow trout meat in Shahre-kord (Iran) markets before and after frying. After randomized collection of 50 samples of fish in Shahre-kord markets in a six months period were examined. The prepared samples were examined for OTC residues using HPLC analytical method before and after frying. Results showed that 3 (6%) of the samples before frying and 12 (24%) after frying were having lower than Maximum residual limits (MRLs) in Codex alimentarius. However, mean OTC residues before and after frying samples were above MRLs. The mean amounts of OTC were 2260 +/- 1090 and 1110 +/- 930 ng g(-1) before and after frying, respectively. These findings show that the frying of fish reduces OTC residual. Nevertheless, the usage of OTC should be reduced to an acceptable level in fishery industry.

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

    SciTech Connect

    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 movedmore » 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

  12. Evidence of spring spawning lake trout in Lake Superior

    USGS Publications Warehouse

    Bronte, Charles R.

    1993-01-01

    In 1992, the U. S. Fish and Wildlife Service began research on the life history, population dynamics, and stock delineation of siscowet lake trout Salvelinus namaycush siscowet in Lake Superior. Siscowet were captured with gill nets in 80-150 m of water on 23-26 April 1992 north of the Apostle Islands in western Lake Superior. Of 91 captured siscowets, one male had fully developed testes in nearly ripe condition and one female had eggs running from the vent. This observation represents the earliest dates that lake trout of any morphotype have been found in spawning or near-spawning condition.

  13. Residue dynamics of quinaldine and TFM in rainbow trout

    USGS Publications Warehouse

    Hunn, J.B.; Allen, J.L.

    1975-01-01

    Study of the residue dynamics of 2-methylquinoline (quinaldine) and 3- trifluoromethy1-4-nitrophenol (TFM) in rainbow trout yielded the following findings: (1) Uptake and distribution of TFM by trout was influenced by the biotransformation of the lipid-soluble free phenol. No such effect was observed with quinaldine. (2) Disappearance of quinaldine and TFM from gallbladder bile was slower than from plasma or muscle during 24 hr of withdrawal in fresh water. (3) The conc of TFM conjugate may exceed that of free TFM in bile by a factor of 10 Super(3).

  14. Ecological segregation moderates a climactic conclusion to trout hybridization.

    PubMed

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

    2017-12-01

    For decades, it has been assumed that introgressive hybridization between introduced rainbow trout and native cutthroat trout in western North America will lead to genomic extinction of the latter. A broad-scale re-examination of their interaction indicates that ecological differences between these species and demographic processes are dictating the location and extent of their hybrid zones, and that runaway introgression between these taxa is unlikely. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  15. Investigations into the Early Life-history of Naturally Produced Spring Chinook Salmon and Summer Steelhead in the Grande Ronde River Basin, Annual Report 2001.

    SciTech Connect

    Reischauer, Alyssa; Monzyk, Frederick; Van Dyke, Erick

    2003-06-01

    We determined migration timing and abundance of juvenile spring chinook salmon Oncorhynchus tshawytscha and juvenile steelhead/rainbow trout Oncorhynchus mykiss using rotary screw traps on four streams in the Grande Ronde River basin during the 2001 migratory year (MY 2001) from 1 July 2000 through 30 June 2001. Based on migration timing and abundance, two distinct life-history strategies of juvenile spring chinook and O. mykiss could be distinguished. An 'early' migrant group left upper rearing areas from 1 July 2000 through 29 January 2001 with a peak in the fall. A 'late' migrant group descended from upper rearing areas from 30more » January 2001 through 30 June 2001 with a peak in the spring. The migrant population of juvenile spring chinook salmon in the upper Grande Ronde River in MY 2001 was very low in comparison to previous migratory years. We estimated 51 juvenile spring chinook migrated out of upper rearing areas with approximately 12% of the migrant population leaving as early migrants to overwinter downstream. In the same migratory year, we estimated 16,067 O. mykiss migrants left upper rearing areas with approximately 4% of these fish descending the upper Grande Ronde River as early migrants. At the Catherine Creek trap, we estimated 21,937 juvenile spring chinook migrants in MY 2001. Of these migrants, 87% left upper rearing areas early to overwinter downstream. We also estimated 20,586 O. mykiss migrants in Catherine Creek with 44% leaving upper rearing areas early to overwinter downstream. At the Lostine River trap, we estimated 13,610 juvenile spring chinook migrated out of upper rearing areas with approximately 77% migrating early. We estimated 16,690 O. mykiss migrated out of the Lostine River with approximately 46% descending the river as early migrants. At the Minam River trap, we estimated 28,209 juvenile spring chinook migrated out of the river with 36% migrating early. During the same period, we estimated 28,113 O. mykiss with

  16. Passage Distribution and Federal Columbia River Power System Survival for Steelhead Kelts Tagged Above and at Lower Granite Dam, Year 2

    SciTech Connect

    Colotelo, Alison H.A.; Harnish, Ryan A.; Jones, Bryan W.

    2014-12-15

    Steelhead (Oncorhynchus mykiss) populations have declined throughout their range in the last century and many populations, including those of the Snake River Basin are listed under the Endangered Species Act of 1973. The reasons for their decline are many and complex, but include habitat loss and degradation, overharvesting, and dam construction. The 2008 Biological Opinion calls for an increase in the abundance of female steelhead through an increase in iteroparity (i.e., repeat spawning) and this can be realized through a combination of reconditioning and in-river survival of migrating kelts. The goal of this study is to provide the data necessarymore » to inform fisheries managers and dam operators of Snake River kelt migration patterns, survival, and routes of dam passage. Steelhead kelts (n = 487) were captured and implanted with acoustic transmitters and passive integrated transponder (PIT)-tags at the Lower Granite Dam (LGR) Juvenile Fish Facility and at weirs located in tributaries of the Snake and Clearwater rivers upstream of LGR. Kelts were monitored as they moved downstream through the Federal Columbia River Power System (FCRPS) by 15 autonomous and 3 cabled acoustic receiver arrays. Cabled receiver arrays deployed on the dam faces allowed for three-dimensional tracking of fish as they approached the dam face and were used to determine the route of dam passage. Overall, 27.3% of the kelts tagged in this study successfully migrated to Martin Bluff (rkm 126, as measured from the mouth of the Columbia River), which is located downstream of all FCRPS dams. Within individual river reaches, survival per kilometer estimates ranged from 0.958 to 0.999; the lowest estimates were observed in the immediate forebay of FCRPS dams. Steelhead kelts tagged in this study passed over the spillway routes (spillway weirs, traditional spill bays) in greater proportions and survived at higher rates compared to the few fish passed through powerhouse routes (turbines and

  17. Passage Distribution and Federal Columbia River Power System Survival for Steelhead Kelts Tagged Above and at Lower Granite Dam, Year 2

    SciTech Connect

    Colotelo, Alison HA; Harnish, Ryan A.; Jones, Bryan W.

    2014-03-28

    Steelhead (Oncorhynchus mykiss) populations have declined throughout their range in the last century and many populations, including those of the Snake River Basin are listed under the Endangered Species Act of 1973. The reasons for their decline are many and complex, but include habitat loss and degradation, overharvesting, and dam construction. The 2008 Biological Opinion calls for an increase in the abundance of female steelhead through an increase in iteroparity (i.e., repeat spawning) and this can be realized through a combination of reconditioning and in-river survival of migrating kelts. The goal of this study is to provide the data necessarymore » to inform fisheries managers and dam operators of Snake River kelt migration patterns, survival, and routes of dam passage. Steelhead kelts (n = 487) were captured and implanted with acoustic transmitters and passive integrated transponder (PIT)-tags at the Lower Granite Dam (LGR) Juvenile Fish Facility and at weirs located in tributaries of the Snake and Clearwater rivers upstream of LGR. Kelts were monitored as they moved downstream through the Federal Columbia River Power System (FCRPS) by 15 autonomous and 3 cabled acoustic receiver arrays. Cabled receiver arrays deployed on the dam faces allowed for three-dimensional tracking of fish as they approached the dam face and were used to determine the route of dam passage. Overall, 27.3% of the kelts tagged in this study successfully migrated to Martin Bluff (rkm 126, as measured from the mouth of the Columbia River), which is located downstream of all FCRPS dams. Within individual river reaches, survival per kilometer estimates ranged from 0.958 to 0.999; the lowest estimates were observed in the immediate forebay of FCRPS dams. Steelhead kelts tagged in this study passed over the spillway routes (spillway weirs, traditional spill bays) in greater proportions and survived at higher rates compared to the few fish passed through powerhouse routes (turbines and

  18. Cannibalism in non-native brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss stream-dwelling populations.

    PubMed

    Musseau, C; Vincenzi, S; Jesenšek, D; Crivelli, A J

    2017-12-01

    Introduced and allopatric populations of brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss were sampled in Slovenia for stable isotope analysis to assess dietary niche shifts through ontogeny and estimate the propensity for cannibalism. Both S. trutta and O. mykiss are cannibals, with higher average relative contribution of conspecific assimilated energy for S. trutta (27·9%) compared with O. mykiss (7·7%). The smallest cannibal was 166 mm in the S. trutta population and 247 mm in the O. mykiss population. © 2017 The Fisheries Society of the British Isles.

  19. The fishing and natural mortality of large, piscivorous Bull Trout and Rainbow Trout in Kootenay Lake, British Columbia (2008-2013).

    PubMed

    Thorley, Joseph L; Andrusak, Greg F

    2017-01-01

    Estimates of fishing and natural mortality are important for understanding, and ultimately managing, commercial and recreational fisheries. High reward tags with fixed station acoustic telemetry provides a promising approach to monitoring mortality rates in large lake recreational fisheries. Kootenay Lake is a large lake which supports an important recreational fishery for large Bull Trout and Rainbow Trout. Between 2008 and 2013, 88 large (≥500 mm) Bull Trout and 149 large (≥500 mm) Rainbow Trout were marked with an acoustic transmitter and/or high reward ($100) anchor tags in Kootenay Lake. The subsequent detections and angler recaptures were analysed using a Bayesian individual state-space Cormack-Jolly-Seber (CJS) survival model with indicator variable selection. The final CJS survival model estimated that the annual interval probability of being recaptured by an angler was 0.17 (95% CRI [0.11-0.23]) for Bull Trout and 0.14 (95% CRI [0.09-0.19]) for Rainbow Trout. The annual interval survival probability for Bull Trout was estimated to have declined from 0.91 (95% CRI [0.76-0.97]) in 2009 to just 0.46 (95% CRI [0.24-0.76]) in 2013. Rainbow Trout survival was most strongly affected by spawning. The annual interval survival probability was 0.77 (95% CRI [0.68-0.85]) for a non-spawning Rainbow Trout compared to 0.41 (95% CRI [0.30-0.53]) for a spawner. The probability of spawning increased with the fork length for both species and decreased over the course of the study for Rainbow Trout. Fishing mortality was relatively low and constant while natural mortality was relatively high and variable. The results indicate that angler effort is not the primary driver of short-term population fluctations in the Rainbow Trout abundance. Variation in the probability of Rainbow Trout spawning suggests that the spring escapement at the outflow of Trout Lake may be a less reliable index of abundance than previously assumed. Multi-species stock assessment models need to

  20. Interspecific interactions between brown trout and slimy sculpin in stream enclosures

    USGS Publications Warehouse

    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.

  1. Brook trout movement in response to temperature, flow, and thermal refugia within a complex Appalachian riverscape

    USGS Publications Warehouse

    Petty, J. Todd; Hansbarger, Jeff L.; Huntsman, Brock M.; Mazik, Patricia M.

    2012-01-01

    We quantified movements of brook trout Salvelinus fontinalis and brown trout Salmo trutta in a complex riverscape characterized by a large, open-canopy main stem and a small, closed-canopy tributary in eastern West Virginia, USA. Our objectives were to quantify the overall rate of trout movement and relate movement behaviors to variation in streamflow, water temperature, and access to coldwater refugia. The study area experienced extremely high seasonal, yearly, and among-stream variability in water temperature and flow. The relative mobility of brook trout within the upper Shavers Fork watershed varied significantly depending on whether individuals resided within the larger main stem or the smaller tributary. The movement rate of trout inhabiting the main stem during summer months (50 m/d) was an order of magnitude higher than that of tributary fish (2 m/d). Movement rates of main-stem-resident brook trout during summer were correlated with the maximum water temperature experienced by the fish and with the fish's initial distance from a known coldwater source. For main-stem trout, use of microhabitats closer to cover was higher during extremely warm periods than during cooler periods; use of microhabitats closer to cover during warm periods was also greater for main-stem trout than for tributary inhabitants. Main-stem-resident trout were never observed in water exceeding 19.5°C. Our study provides some of the first data on brook trout movements in a large Appalachian river system and underscores the importance of managing trout fisheries in a riverscape context. Brook trout conservation in this region will depend on restoration and protection of coldwater refugia in larger river main stems as well as removal of barriers to trout movement near tributary and main-stem confluences.

  2. Influence of landscape-scale factors in limiting brook trout populations in Pennsylvania streams

    USGS Publications Warehouse

    Kocovsky, P.M.; Carline, R.F.

    2006-01-01

    Landscapes influence the capacity of streams to produce trout through their effect on water chemistry and other factors at the reach scale. Trout abundance also fluctuates over time; thus, to thoroughly understand how spatial factors at landscape scales affect trout populations, one must assess the changes in populations over time to provide a context for interpreting the importance of spatial factors. We used data from the Pennsylvania Fish and Boat Commission's fisheries management database to investigate spatial factors that affect the capacity of streams to support brook trout Salvelinus fontinalis and to provide models useful for their management. We assessed the relative importance of spatial and temporal variation by calculating variance components and comparing relative standard errors for spatial and temporal variation. We used binary logistic regression to predict the presence of harvestable-length brook trout and multiple linear regression to assess the mechanistic links between landscapes and trout populations and to predict population density. The variance in trout density among streams was equal to or greater than the temporal variation for several streams, indicating that differences among sites affect population density. Logistic regression models correctly predicted the absence of harvestable-length brook trout in 60% of validation samples. The r 2-value for the linear regression model predicting density was 0.3, indicating low predictive ability. Both logistic and linear regression models supported buffering capacity against acid episodes as an important mechanistic link between landscapes and trout populations. Although our models fail to predict trout densities precisely, their success at elucidating the mechanistic links between landscapes and trout populations, in concert with the importance of spatial variation, increases our understanding of factors affecting brook trout abundance and will help managers and private groups to protect and

  3. Genetic Structure of Pacific Trout at the Extreme Southern End of Their Native Range

    PubMed Central

    Abadía-Cardoso, Alicia; Garza, John Carlos; Mayden, Richard L.; García de León, Francisco Javier

    2015-01-01

    Salmonid fishes are cold water piscivores with a native distribution spanning nearly the entire temperate and subarctic northern hemisphere. Trout in the genus Oncorhynchus are the most widespread salmonid fishes and are among the most important fish species in the world, due to their extensive use in aquaculture and valuable fisheries. Trout that inhabit northwestern Mexico are the southernmost native salmonid populations in the world, and the least studied in North America. They are unfortunately also facing threats to their continued existence. Previous work has described one endemic species, the Mexican golden trout (O. chrysogaster), and one endemic subspecies, Nelson’s trout (O. mykiss nelsoni), in Mexico, but previous work indicated that there is vastly more biodiversity in this group than formally described. Here we conducted a comprehensive genetic analysis of this important group of fishes using novel genetic markers and techniques to elucidate the biodiversity of trout inhabiting northwestern Mexico, examine genetic population structure of Mexican trout and their relationships to other species of Pacific trout, and measure introgression from non-native hatchery rainbow trout. We confirmed substantial genetic diversity and extremely strong genetic differentiation present in the Mexican trout complex, not only between basins but also between some locations within basins, with at least four species-level taxa present. We also revealed significant divergence between Mexican trout and other trout species and found that introgression from non-native rainbow trout is present but limited, and that the genetic integrity of native trout is still maintained in most locations. This information will help to guide effective conservation strategies for this important group of fishes. PMID:26509445

  4. Starvation resistance in lake trout fry

    USGS Publications Warehouse

    Edsall, Thomas A.; Manny, Bruce A.; Kennedy, Gregory W.

    2003-01-01

    Newly hatched fry were acclimated to 7 or 12A?C and either fed daily (controls) or denied food for varying lengths of time and then fed daily until the end of the study (day 91 at 7A?C and day 43 at 12A?C). Growth was reduced by delays in the onset of feeding of 27 or more days at 7A?C and 7 or more days at 12A?C. Mortality of fry unfed for more than 34 days at 7A?C, or more than 21 days at 12A?C, was higher than among controls. Daily mortality increased with the length of the food deprivation period and did not cease immediately when food was made available, but reached zero by the end of the study. Mortality among unfed fry reached 50% in about 59 days at 7A?C and 32 days at 12A?C. Study results permitted calculation of the 'point-of-no-return' (PNR) mortality, which included the mortality that occurred during the period of food deprivation, and also the delayed component of mortality that was directly attributable to starvation and that occurred after food was made available. The PNR for 50% mortality for food-deprived fry occurred after 52 days at 7A?C and 24 days at 12A?C. Thus, both measures of mortality indicate that lake trout fry would be highly resistant to death by starvation in the thermal habitat they would be expected to occupy in the Great Lakes. We conclude that a more likely adverse effect of reduced food availability would result from a reduction in growth rate that extends the length of time fry remain small and vulnerable to predation by adult alewives and other non-native fishes with which they associate.

  5. Habitat suitability index models: Cutthroat trout

    USGS Publications Warehouse

    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.

  6. Guidelines for monitoring and adaptively managing restoration of Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) on the Elwha River

    USGS Publications Warehouse

    Peters, R.J.; Duda, J.J.; Pess, G.R.; Zimmerman, M.; Crain, P.; Hughes, Z.; Wilson, A.; Liermann, M.C.; Morley, S.A.; McMillan, J.; Denton, K.; Warheit, K.

    2014-01-01

    The restoration of the migration route to spawning and rearing habitats upstream of the former Glines Canyon Dam represents a great opportunity for salmon on the Olympic Peninsula. By removing two aging structures, it will be possible for all 5 species of salmon and steelhead to return to wild stretches of the Elwha River and major floodplain habitat characterized by multiple channels, as well as significant portions of numerous tributaries. Measuring the progress of restoration, from the perspective of both salmon populations and the ecosystem upon which they depend, is a great test for a collaborative team of scientists. The normally challenging conditions of working in a steep gradient, high velocity wilderness river are exacerbated by the release of millions of cubic yards of sediment that had accumulated in the reservoirs. After the first two years of the dam decommissioning process, this release has changed the ecology of the river, estuary, and nearshore habitats downstream of the dams. Our goal in developing the guidelines described is to provide a roadmap for tracking what hopefully will become a successful outcome. If successfully implemented, this information should prove useful as others begin planning for the removal, alteration, or reconstruction of dams throughout North America and elsewhere, an inevitable outcome of an aging dam infrastructure.

  7. Environmental Factors Affecting Brook Trout Occurrence in Headwater Stream Segments

    Treesearch

    Yoichiro Kanno; Benjamin H. Letcher; Ana L. Rosner; Kyle P. O' Neil; Keith H. Nislow

    2015-01-01

    We analyzed the associations of catchment-scale and riparian-scale environmental factors with occurrence of Brook Trout Salvelinus fontinalis in Connecticut headwater stream segments with catchment areas of 15 < km2. A hierarchical Bayesian approach was applied to a statewide stream survey data set, in which Brook...

  8. Fine Sediment Effects on Brook Trout Eggs in Laboratory Streams

    Treesearch

    David G. Argent; Patricia A. Flebbe

    1999-01-01

    This study was designed to determine effects of different fine sediments (0.43-0.85 mm in diameter) on survival of brook trout (Salvelinus fontinalis) eggs during early developmental stages under laboratory conditions. Intragravel permeability and dissolved oxygen declined with increasing fine sediment amounts. Survival at each developmental stage...

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

    Treesearch

    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...

  10. Lake Michigan lake trout PCB model forecast post audit

    EPA Science Inventory

    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...

  11. Cryopreservation of sperm of the endangered gila trout, Oncorhynchus gilae

    USDA-ARS?s Scientific Manuscript database

    Gila trout, Oncorhynchus gilae, are native to the headwaters of the Gila River drainage in New Mexico and Arizona and the headwaters of the Verde River drainage in Arizona. The species is currently protected as endangered under the Endangered Species Act. Cryopreservation of sperm is now a widely us...

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

    Treesearch

    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....

  13. Weissellosis: An Emerging Disease Of Farmed Rainbow Trout

    USDA-ARS?s Scientific Manuscript database

    Weissella ceti is a gram positive bacterium associated with Weissellosis, an emerging disease of farmed rainbow trout. This disease can result in high mortality in large fish (0.5-1.0 kg) and hence can cause significant economic loss. In the summer of 2011, severe Weissellosis outbreaks were identif...

  14. Selective breeding of food sized rainbow trout against Flavobacteriosis

    USDA-ARS?s Scientific Manuscript database

    Selective breeding of rainbow trout is an important component of an integrated fish health management program. The current goals of our selective breeding program are to improve disease resistance, growth and survival in a reuse water environment. To improve these traits, data are recorded on thousa...

  15. Identification of commercial rainbow trout strains using a SNP panel

    USDA-ARS?s Scientific Manuscript database

    Assessment of population genetic differentiation is critical for selective breeding of rainbow trout, and identification of fish strains is often required to address production issues arising on fish farms. The objectives of this study were: (1) to characterize the genetic differentiation of the eig...

  16. Selective breeding of food size rainbow trout against Flavobacteriosis

    USDA-ARS?s Scientific Manuscript database

    Selective breeding of rainbow trout is an important component of an integrated fish health management program. The current goals of our selective breeding program are to improve disease resistance, growth and survival in a reuse water environment. To improve these traits, data are recorded on thousa...

  17. Optimization of a UDP-glucuronosyltransferase assay for trout ...

    EPA Pesticide Factsheets

    An existing assay for hepatic UDP-glucuronosyltransferase (UGT) activity was optimized for use with trout liver S9 fractions. Individual experiments were conducted to determine the time dependence of UGT activity as well as optimal levels of S9 protein, uridine 5’-diphosphoglucuronic acid (UDPGA; a necessary cofactor), alamethicin (a pore-forming agent added to eliminate latency), and substrate (p-nitrophenol). Addition of Mg2+ (to 1 mM) or bovine serum albumin (BSA; to 2% w/v) had variable effects on activity, but these effects were minor. Eliminating alamethicin from the system resulted in very low levels of activity. A portion of this activity could be recovered by adding Triton X-100 or Brij 58; however, the optimal concentration range for either detergent was very narrow. All studies were performed under physiological conditions (pH 7.8, 11 °C) to support ongoing development of methods for extrapolating in vitro rates of biotransformation to the intact animal. When expressed on a pmol/min/g liver basis, UGT activities determined using this updated assay were substantially higher than those reported previously for uninduced trout. The purpose of the present study was to optimize an existing in vitro assay for hepatic UGT activity in rainbow trout. The original assay, adapted here for use with trout S9 fractions, was updated by incorporating a membrane disrupting agent (alamethicin) to reduce latency. Additional experiments were conducted to evaluate

  18. Conservation of native Pacific trout diversity in Western North America

    Treesearch

    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...

  19. Toxicokinetics of perfluorooctane sulfonate in rainbow trout (Oncorhynchus mykiss)

    EPA Science Inventory

    Rainbow trout (Oncorhynchus mykiss) confined to respirometer-metabolism chambers were dosed with perfluorooctane sulfonate (PFOS) by intra-arterial injection and sampled to obtain concentration time-course data for plasma, and either urine or expired water. The data were then an...

  20. DIFFERENTIATING MECHANISMS OF REACTIVE CHEMICAL TOXICITY IN ISOLATED TROUT HEPATOCYTES

    EPA Science Inventory

    The toxicity of four quinones, 2,3-dimethoxy-1,4-naphthoquinone (DMONQ), 2-methyl 1,4-naphthoquinone (MNQ ),1,4-naphthoquinone (NQ), and 1,4-benzoquinone (BQ), which redox cycle or arlyate in mammalian cells, was determined in isolated trout (Oncorhynchus mykiss) hepatocytes. Mor...

  1. METHOXYCHLOR METABOLISM AND VITELLOGENESIS IN MALE RAINBOW TROUT LIVER SLICES

    EPA Science Inventory

    Induction of vitellogenin (VTG) in male fish has become an accepted biomarker to xenoestrogenicity. This study utilized the male rainbow trout liver slice model to determine the estrogenicity of parent compound, methoxychlor (MXC) and metabolites, di-hydroxy methoxychlor (HPTE) a...

  2. Colorado River cutthroat trout: a technical conservation assessment

    Treesearch

    Michael K. Young

    2008-01-01

    The Colorado River cutthroat trout (Oncorhynchus clarkii pleuriticus) was once distributed throughout the colder waters of the Colorado River basin above the Grand Canyon. About 8 percent of its historical range is occupied by unhybridized or ecologically significant populations. It has been petitioned for listing under the Endangered Species Act...

  3. DNA Fingerprinting of Trout Lilies: A High School Student Project.

    ERIC Educational Resources Information Center

    Vann, Carolyn N.; Saxon, Herbert L.; Brblic, Tom; Elliades, Stacie; Lambert, Scott; Shaw, Jake; Smith, Ryan; Inman, Megan

    1998-01-01

    Reports on a student's research project on the degree of genetic diversity within the trout lily species. Enables a rough prediction of the continuance of the species and provides insight into how to manage plants that might be endangered. Contains 16 references. (DDR)

  4. Angler specialization among salmon and trout anglers on Lake Ontario

    Treesearch

    Chad P. Dawson

    1995-01-01

    The angler specialization concept was studied using the expectancy model of motivation. An exploratory study of' Lake Ontario salmon and trout anglers was conducted to test the relationships between the variables of the expectancy model of motivation and actual angling participation.

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

    USGS Publications Warehouse

    Schwindt, Adam R.; Truelove, Nathan; Schreck, Carl B.; Fournie, John W.; Landers, Dixon H.; Kent, Michael L.

    2006-01-01

    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 occur in salmonids but are poorly organized, irregularly shaped, and are generally smaller than those in derived teleosts. These features complicate quantification, and thus these fishes have seldom been used in studies correlating MAs with environmental stressors. To alleviate these complications, we developed color filtering algorithms for use with the software package ImagePro Plus® (Media Cybernetics) that select and quantify pigmented area (i.e. colors ranging from gold to brown to black) in tissue sections. Image analysis results compared well with subjective scoring when tested on brook trout Salvelinus fontinalis and rainbow trout Oncorhynchus mykiss captured from high-elevation lakes or hatcheries. Macrophage aggregate pigments correlated positively with age and negatively with condition factor. Within individual fish, pigmentation correlated positively among organs, suggesting that the kidney, liver or spleen are suitable indicator organs. In age-matched fishes, MA pigments were not different between hatcheries and lakes in the organs examined. Between lakes, differences in pigments were observed in the kidney and spleen, but were not explained by age, condition factor, sex or maturation state. Our results indicate that quantification of the area occupied by MA pigments is an efficient and accurate means of evaluating MAs in salmonid organs and that organ pigmentation correlates with age and condition factor, as seen in studies with more derived fishes. 

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

    SciTech Connect

    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 kmmore » (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

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

    USGS Publications Warehouse

    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. Initiation, promotion, and inhibition of carcinogenesis in rainbow trout

    SciTech Connect

    Bailey, G.; Selivonchick, D.; Hendricks, J.

    1987-04-01

    The identification of etiological agents in feral fish neoplasia epizootics has been hampered in part by the lack of suitable fish models, and complicated by the likely existence of environmental agents which can act to stimulate or reduce population responses to genotoxin insult. The response of fish to tumor inhibitors and promoters, and the underlying mechanisms of modulation, have been studied in the rainbow trout model. Dietary treatment of trout with the compounds indole-3-carbinol (I3C), ..beta..-napthroflavone (BNF), or the polychlorinated biphenyl (PCB) complex Aroclor 1254, before and during exposure to aflatoxin B/sub 1/ (AFB1), was shown to reduce the finalmore » incidence of hepatocellular carcinoma after 12 months, compared to fish receiving AFB1 only. By contrast, treatment of trout with BNF or I3C following AFB1 initiation led to a significant enhancement of ultimate tumor response, Similarly, simultaneous treatment of trout with PCB and the carcinogen N-nitrosodiethylamine led to syncarcinogenic enhancement, rather than inhibition, of tumor response. Mechanisms of inhibition of AFB1 carcinogenesis by PCB, BNF, and I3C were investigated. PCB and BNF, but not I3C, are known to be strong inducers of trout cytochrome P448 and associated activities. Dietary induction by BNF or PCB was shown to be accompanied in solvated hepatocytes by considerably altered AFB1 metabolism, and by significantly reduced rates of DNA adduct formation for all three agents. All agents differentially altered in vivo AFB1 pharmacokinetics, enhanced bile elimination of AFB1 as the aflatoxicol-M1 glucuronide, and significantly reduced peak levels of liver DNA adduct formation.« less

  9. Analyzing tradeoffs between the threat of invasion by brook trout and effects of intentional isolation for native westslope cutthroat trout

    Treesearch

    Douglas P. Peterson; Bruce E. Rieman; Jason B. Dunham; Kurt D. Fausch; Michael K. Young

    2007-01-01

    Native fishes often face simultaneous threats from habitat fragmentation and invasion by nonnative trout. 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 most appropriate. We developed a Bayesian belief...

  10. Temporal genetic monitoring of hybridization between native westslope cutthroat trout and introduced rainbow trout in the Stehekin River, Washington

    USGS Publications Warehouse

    Ostberg, Carl O.; Chase, Dorothy M.

    2012-01-01

    Introgressive hybridization with introduced rainbow trout (RBT) (Oncorhynchus mykiss) has led to the loss of native cutthroat trout species (O. clarkii) throughout their range, creating conservation concerns. Monitoring temporal hybridization trends provides resource managers with a tool for determining population status and information for establishing conservation goals for native cutthroat trout. In this study, we re-sampled six locations in 2010 within the Stehekin River watershed, North Cascades National Park, which were originally sampled between 1999 and 2003. We used genetic markers to monitor changes in hybridization levels between sampling periods in the native westslope cutthroat trout (WCT) (O. c. lewisi) stemming from past RBT introductions. Additionally, two new locations from the lower Stehekin drainage were added to the baseline data. We found that the frequency of WCT, RBT, and their hybrids was not significantly different between monitoring periods, but that RBT allele frequencies decreased in two locations and increased in one location. We also found a consistent, substantial reduction in the frequency of RBT alleles over the monitoring period in the Stehekin River upstream of Bridge Creek (SR3) compared to the Stehekin River downstream of Bridge Creek (SR1 -2) and within lower Bridge Creek (BR1) although these three locations are confined to a small geographic area (approximately 5 km). Ecological and/or evolutionary processes likely restrict the dispersal of RBT alleles in the Stehekin River upstream of Bridge Creek.

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

    USGS Publications Warehouse

    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.

  12. Accumulation of PCBs by lake trout (Salvelinus namaycush): an individual-based model approach

    USGS Publications Warehouse

    Madenjian, Charles P.; Carpenter, Stephen R.; Eck, Gary W.; Miller, Michael A.

    1993-01-01

    To explain the variation in growth and in concentration of polychlorinated biphenyls (PCBs) among individual fish, an individual-based model (IBM) was applied to the lake trout (Salvelinus namaycush) population in Lake Michigan. The IBM accurately represented the variation in growth exhibited by the different age classes of lake trout. Uncertainty analysis of the IBM revealed that mean PCB concentration for the lake trout population was most sensitive to PCB concentration in their prey. The variability in PCB concentration among lake trout individuals was not adequately explained by the IBM, unless variation in prey fish PCBs was included in the model. To accomplish this, the simulated lake trout population was divided into subsets subjected to different levels of PCB concentration in the prey fish. Thus, model results indicated that variability in prey fish PCB concentration was an important component of the variation in PCB concnetration observed among individual lake trout comprising the Lake Michigan population.

  13. The role of encoding in reality monitoring: a running memory test with Alzheimer's type dementia.

    PubMed

    Mammarella, Nicola; Fairfield, Beth

    2006-10-01

    Reality monitoring refers to the discrimination between memories of internal and external events (e.g., Johnson & Raye, 1981). A total of 28 healthy older adults and 28 older adults with Alzheimer's type dementia (DAT) were asked to perform or to imagine performing simple action statements in a running memory test. This task required participants to tell whether the action statement had been carried out or imagined, or whether it was new at unpredictable intervals. The results indicated that older adults with DAT had greater difficulty in reality monitoring than did the healthy control group. The finding is discussed in terms of the role of working memory functions in reality monitoring.

  14. 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)

    USGS Publications Warehouse

    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.

  15. Potential population and assemblage influences of non-native trout on native nongame fish in Nebraska headwater streams

    USGS Publications Warehouse

    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.

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

    USGS Publications Warehouse

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

    2011-01-01

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

  17. Summer microhabitat use of fluvial bull trout in Eastern Oregon streams

    USGS Publications Warehouse

    Al-Chokhachy, R.; Budy, P.

    2007-01-01

    The management and recovery of populations of bull trout Salvelinus confluentus requires a comprehensive understanding of habitat use across different systems, life stages, and life history forms. To address these needs, we collected microhabitat use and availability data in three fluvial populations of bull trout in eastern Oregon. We evaluated diel differences in microhabitat use, the consistency of microhabitat use across systems and size-classes based on preference, and our ability to predict bull trout microhabitat use. Diel comparisons suggested bull trout continue to use deeper microhabitats with cover but shift into significantly slower habitats during nighttime periods; however, we observed no discrete differences in substrate use patterns across diel periods. Across life stages, we found that both juvenile and adult bull trout used slow-velocity microhabitats with cover, but the use of specific types varied. Both logistic regression and habitat preference analyses suggested that adult bull trout used deeper habitats than juveniles. Habitat preference analyses suggested that bull trout habitat use was consistent across all three systems, as chi-square tests rejected the null hypotheses that microhabitats were used in proportion to those available (P < 0.0001). Validation analyses indicated that the logistic regression models (juvenile and adult) were effective at predicting bull trout absence across all tests (specificity values = 100%); however, our ability to accurately predict bull trout absence was limited (sensitivity values = 0% across all tests). Our results highlight the limitations of the models used to predict microhabitat use for fish species like bull trout, which occur at naturally low densities. However, our results also demonstrate that bull trout microhabitat use patterns are generally consistent across systems, a pattern that parallels observations at both similar and larger scales and across life history forms. Thus, our results, in

  18. Molecular analysis of population genetic structure and recolonization of rainbow trout following the Cantara spill

    USGS Publications Warehouse

    Nielsen, J.L.; Heine, Erika L.; Gan, Christina A.; Fountain, Monique C.

    2000-01-01

    Mitochondrial DNA (mtDNA) sequence and allelic frequency data for 12 microsatellite loci were used to analyze population genetic structure and recolonization by rainbow trout, Oncorhynchus mykiss, following the 1991 Cantara spill on the upper Sacramento River, California. Genetic analyses were performed on 1,016 wild rainbow trout collected between 1993 and 1996 from the mainstem and in 8 tributaries. Wild trout genotypes were compared to genotypes for 79 Mount Shasta Hatchery rainbow trout. No genetic heterogeneity was found 2 years after the spill (1993) between tributary populations and geographically proximate mainstem fish, suggesting recolonization of the upper mainstem directly from adjacent tributaries. Trout collections made in 1996 showed significant year-class genetic variation for mtDNA and microsatellites when compared to fish from the same locations in 1993. Five years after the spill, mainstem populations appeared genetically mixed with no significant allelic frequency differences between mainstem populations and geographically proximate tributary trout. In our 1996 samples, we found no significant genetic differences due to season of capture (summer or fall) or sampling technique used to capture rainbow trout, with the exception of trout collected by electrofishing and hook and line near Prospect Avenue. Haplotype and allelic frequencies in wild rainbow trout populations captured in the upper Sacramento River and its tributaries were found to differ genetically from Mount Shasta Hatchery trout for both years, with the notable exception of trout collected in the lower mainstem river near Shasta Lake, where mtDNA and microsatellite data both suggested upstream colonization by hatchery fish from the reservoir. These data suggest that the chemical spill in the upper Sacramento River produced significant effects over time on the genetic population structure of rainbow trout throughout the entire upper river basin.

  19. Lake trout population dynamics in the Northern Refuge of Lake Michigan: implications for future rehabilitation

    USGS Publications Warehouse

    Madenjiana, Charles P.; DeSorcie, Timothy J.

    2010-01-01

    The Northern Refuge was established in 1985 as part of the lake trout Salvelinus namaycush rehabilitation effort for Lake Michigan. To evaluate progress toward lake trout rehabilitation in the Northern Refuge, we conducted annual (1991–2008) gill-net surveys in the fall to assess the adult population and beam trawl surveys in the spring to assess naturally reproduced age-0 lake trout. Our criteria for evaluating progress included the density of “wild” age-0 fish within the Northern Refuge, the proportion of wild fish within the adult population, density of spawners, adult survival, growth, and wounding rate by sea lampreys Petromyzon marinus. No wild age-0 lake trout were caught in the Northern Refuge during 1991–2008. Overall, wild lake trout did not recruit to the adult population to any detectable degree. The mean density of spawning lake trout decreased from 45 fish·305 m of gill net−1·d−1 during 1991–1999 to only 4 fish·305 m−1·d−1 during 2000–2008. Although the sea lamprey wounding rate more than doubled between these two time periods, catch curve analysis revealed that mortality of adult lake trout actually decreased between the two periods. Therefore, the 90% decrease in abundance of spawning lake trout between the two periods could not be attributed to increased sea lamprey predation but instead was probably due in part to the reduced lake trout stocking rate during 1995–2005. The paucity of natural reproduction in the Northern Refuge during 1991–2008 most likely resulted from alewife Alosa pseudoharengus interference with lake trout reproduction and from the relatively low lake trout spawner density during 2000–2008. Our results suggest that the annual stocking rate of lake trout yearlings should be increased to at least 250,000 fish/reef to achieve greater densities of spawners.

  20. Effect on tricaine methanesulfonate (MS-222) on hematocrit values in rainbow trout (Salmo gairdneri)

    USGS Publications Warehouse

    Reinitz, G.L.; Rix, J.

    1977-01-01

    1. Anesthesia of rainbow trout (Salmo gairdneri) with 70 ppm tricaine methanesulfonate (MS-222) for 3-9 min resulted in a linear increase in hematocrit.2. Handling of unanesthetized trout caused a higher and more variable hematocrit reading than did exposure to MS-222 for up to 3 min.3. The range and standard error of hematocrit readings was smallest in trout treated with MS-222 for 1 min.

  1. Assessment of lake trout spawning habitat quality in central Lake Huron by submarine

    USGS Publications Warehouse

    Manny, Bruce A.; Edsall, Thomas A.

    1989-01-01

    Interstitial water quality was measured using a submersible at seven locations on Six Fathom Bank. Historically, the bank was an important lake trout spawning ground. It is currently the focus of coordinated, interagency efforts to rehabilitate lake trout in Lake Huron. Water quality, evaluated from measurements of biochemical oxygen demand, dissolved oxygen, ammonia, and hydrogen sulfide among the rocks, would not prevent lake trout eggs from hatching successfully on the bank.

  2. Experimental evaluation of rainbow trout Oncorhynchus mykiss predation on longnose dace Rhinichthys cataractae

    USGS Publications Warehouse

    Turek, Kelly C.; Pegg, Mark A.; Pope, Kevin L.

    2014-01-01

    Laboratory and in-stream enclosure experiments were used to determine whether rainbow trout Oncorhynchus mykiss influence survival of longnose dace Rhinichthys cataractae. In the laboratory, adult rainbow trout preyed on longnose dace in 42% of trials and juvenile rainbow trout did not prey on longnose dace during the first 6 h after rainbow trout introduction. Survival of longnose dace did not differ in the presence of adult rainbow trout previously exposed to active prey and those not previously exposed to active prey ( = 0.28, P = 0.60). In field enclosures, the number of longnose dace decreased at a faster rate in the presence of rainbow trout relative to controls within the first 72 h, but did not differ between moderate and high densities of rainbow trout (F2,258.9 = 3.73, P = 0.03). Additionally, longnose dace were found in 7% of rainbow trout stomachs after 72 h in enclosures. Rainbow trout acclimated to the stream for longer periods had a greater initial influence on the number of longnose dace remaining in enclosures relative to those acclimated for shorter periods regardless of rainbow trout density treatment (F4,148.5 = 2.50, P = 0.04). More research is needed to determine how predation rates will change in natural environments, under differing amounts of habitat and food resources and in the context of whole assemblages. However, if rainbow trout are introduced into the habitat of longnose dace, some predation on longnose dace is expected, even when rainbow trout have no previous experience with active prey.

  3. Ontogenic and spatial patterns in diet and growth of lake trout in Lake Michigan

    USGS Publications Warehouse

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

    1998-01-01

    Lake trout Salvelinus namaycush in nearshore waters of Lake Michigan grow faster than lake trout residing offshore on Sheboygan Reef, which is in midlake. We examined the stomachs of lake trout, spanning ages 1 through 16, caught in both nearshore and offshore environments of Lake Michigan during 1994 and 1995 to determine whether diet differences may be responsible for the difference in growth rate. A comparison of the diets, coupled with bioenergetics modeling, indicated that juvenile lake trout on Sheboygan Reef experienced slow growth due to low food availability rather than to cold water temperatures. The availability of appropriate-size prey appeared to regulate lake trout growth. Small prey fish were probably not readily available to small (200- to 399-mm total length) lake trout on Sheboygan Reef, a substantial portion of whose diet consisted of invertebrates; in contrast, nearshore juveniles had a nearly 100% fish diet. Growth rate on the reef remained slow through intermediate lake trout sizes (400-599 mm total length), presumably due to low availability of rainbow smelt Osmerus mordax on the reef. Once lake trout achieved total lengths of approximately 600 mm, they grew slightly faster on Sheboygan Reef than near shore, indicating that large (>170-mm total length) prey fish were readily available to lake trout in the reef area. On a wet-weight basis, alewife Alosa pseudoharengus dominated the diet of large (a?Y 600 mm total length) lake trout from both the nearshore and offshore regions of the lake, although bloater Coregonus hoyi composed over 30% of the diet on Sheboygan Reef and in southeastern nearshore Lake Michigan. Size of alewife prey increased with lake trout size. The bloater population currently represents the bulk of the biomass of the adult prey fish community, so our diet analysis suggests that large lake trout are continuing to select alewives.

  4. Passage survival of juvenile steelhead, coho salmon, and Chinook salmon in Lake Scanewa and at Cowlitz Falls Dam, Cowlitz River, Washington, 2010–16

    USGS Publications Warehouse

    Liedtke, Theresa L.; Kock, Tobias J.; Hurst, William

    2018-04-03

    A multi-year evaluation was conducted during 2010–16 to evaluate passage survival of juvenile steelhead (Oncorhynchus mykiss), Chinook salmon (O. tshawytscha), and coho salmon (O. kisutch) in Lake Scanewa, and at Cowlitz Falls Dam in the upper Cowlitz River Basin, Washington. Reservoir passage survival was evaluated in 2010, 2011, and 2016, and included the tagging and release of 1,127 juvenile salmonids. Tagged fish were released directly into the Cowlitz and Cispus Rivers, 22.3 and 8.9 km, respectively, upstream of the reservoir, and were monitored as they moved downstream into, and through the reservoir. A single release-recapture survival model was used to analyze detection records and estimate reservoir passage survival, which was defined as successful passage from reservoir entry to arrival at Cowlitz Falls Dam. Tagged fish generally moved quickly downstream of the release sites and, on average, arrived in the dam forebay within 2 d of release. Median travel time from release to first detection at the dam ranged from 0.23 to 0.96 d for juvenile steelhead, from 0.15 to 1.11 d for juvenile coho salmon, and from 0.18 to 1.89 d for juvenile Chinook salmon. Minimum reservoir passage survival probabilities were 0.960 for steelhead, 0.855 for coho salmon and 0.900 for Chinook salmon.Dam passage survival was evaluated at the pilot-study level during 2013–16 and included the tagging and release of 2,512 juvenile salmonids. Juvenile Chinook salmon were evaluated during 2013–14, and juvenile steelhead and coho salmon were evaluated during 2015–16. A paired-release study design was used that included release sites located upstream and downstream of Cowlitz Falls Dam. The downstream release site was positioned at the downstream margin of the dam’s tailrace, which allowed dam passage survival to be measured in a manner that included mortality that occurred in the passage route and in the dam tailrace. More than one-half of the tagged Chinook salmon (52 percent

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

    USGS Publications Warehouse

    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.

  6. Regulation of an unexploited brown trout population in Spruce Creek, Pennsylvania

    USGS Publications Warehouse

    Carline, R.F.

    2006-01-01

    The purpose of this paper is to describe the annual variations in the density of an unexploited population of lotic brown trout Salmo trutta that has been censused annually for 19 years and to explore the importance of density-independent and density-dependent processes in regulating population size. Brown trout density and indices of stream discharge and water temperature were related to annual variations in natural mortality, recruitment, and growth. Annual mortality of age-1 and older (age-1+) brown trout ranged from 0.30 to 0.75 and was best explained by discharge during spring and by brown trout density. Recruitment to age 1 varied fivefold. Density of age-1 brown trout was inversely related to spawner density and positively related to discharge during the fall spawning period. The median length of age-1 brown trout was positively related to discharge during summer and fall. Relative weight was inversely related to the density of age-2+ brown trout. The interactive effects of discharge and brown trout density accounted for most of the annual variation in mortality, recruitment, and growth during the first year of life. Annual trends in the abundance of age-1+ brown trout were largely dictated by natural mortality. ?? Copyright by the American Fisheries Society 2006.

  7. Influence of Didymosphenia geminata blooms on prey composition and associated diet and growth of Brown Trout

    USGS Publications Warehouse

    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.

  8. Temporary Restoration of Bull Trout Passage at Albeni Falls Dam

    SciTech Connect

    Paluch, Mark; Scholz, Allan; McLellan, Holly

    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 acousticmore » 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

  9. Changes in native bull trout and non-native brook trout distributions in the upper Powder River basin after 20 years, relationships to water temperature and implications of climate change

    Treesearch

    Philip J. Howell

    2017-01-01

    Many bull trout populations have declined from non-native brook trout introductions, habitat changes (e.g. water temperature) and other factors. We systematically sampled the distribution of bull trout and brook trout in the upper Powder River basin in Oregon in the 1990s and resampled it in 2013–2015, examined temperature differences in the habitats of the two species...

  10. Surgically Implanted JSATS Micro-Acoustic Transmitters Effects on Juvenile Chinook Salmon and Steelhead Tag Expulsion and Survival, 2010

    SciTech Connect

    Woodley, Christa M.; Carpenter, Scott M.; Carter, Kathleen M.

    2011-09-16

    The purpose of this study was to evaluate survival model assumptions associated with a concurrent study - Acoustic Telemetry Evaluation of Dam Passage Survival and Associated Metrics at John Day, The Dalles, and Bonneville Dams, 2010 by Thomas Carlson and others in 2010 - in which the Juvenile Salmonid Acoustic Telemetry System (JSATS) was used to estimate the survival of yearling and subyearling Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) migrating through the Federal Columbia River Power System (FCRPS). The micro-acoustic transmitter used in these studies is the smallest acoustic transmitter model to date (12 mm long x 5more » mm wide x 4 mm high, and weighing 0.43 g in air). This study and the 2010 study by Carlson and others were conducted by researchers from the Pacific Northwest National Laboratory and the University of Washington for the U.S. Army Corps of Engineers, Portland District, to meet requirements set forth by the 2008 FCRPS Biological Opinion. In 2010, we compared survival, tag burden, and tag expulsion in five spring groups of yearling Chinook salmon (YCH) and steelhead (STH) and five summer groups of subyearling Chinook salmon (SYC) to evaluate survival model assumptions described in the concurrent study. Each tagging group consisted of approximately 120 fish/species, which were collected and implanted on a weekly basis, yielding approximately 600 fish total/species. YCH and STH were collected and implanted from late April to late May (5 weeks) and SYC were collected and implanted from mid-June to mid-July (5 weeks) at the John Day Dam Smolt Monitoring Facility. The fish were collected once a week, separated by species, and assigned to one of three treatment groups: (1) Control (no surgical treatment), (2) Sham (surgical implantation of only a passive integrated transponder [PIT] tag), and (3) Tagged (surgical implantation of JSATS micro-acoustic transmitter [AT] and PIT tags). The test fish were held for 30 days in

  11. Growth of juvenile steelhead Oncorhynchus mykiss under size-selective pressure limited by seasonal bioenergetic and environmental constraints

    USGS Publications Warehouse

    Thompson, Jamie N.; Beauchamp, David A.

    2016-01-01

    Increased freshwater growth of juvenile steelhead Oncorhynchus mykiss improved survival to smolt and adult stages, thus prompting an examination of factors affecting growth during critical periods that influenced survival through subsequent life stages. For three tributaries with contrasting thermal regimes, a bioenergetics model was used to evaluate how feeding rate and energy density of prey influenced seasonal growth and stage-specific survival of juvenile O. mykiss. Sensitivity analysis examined target levels for feeding rate and energy density of prey during the growing season that improved survival to the smolt and adult stages in each tributary. Simulated daily growth was greatest during warmer months (1 July to 30 September), whereas substantial body mass was lost during cooler months (1 December to 31 March). Incremental increases in annual feeding rate or energy density of prey during summer broadened the temperature range at which faster growth occurred and increased the growth of the average juvenile to match those that survived to smolt and adult stages. Survival to later life stages could be improved by increasing feeding rate or energy density of the diet during summer months, when warmer water temperatures accommodated increased growth potential. Higher growth during the summer period in each tributary could improve resiliency during subsequent colder periods that lead to metabolic stress and weight loss. As growth and corresponding survival rates in fresh water are altered by shifting abiotic regimes, it will be increasingly important for fisheries managers to better understand the mechanisms affecting growth limitations in rearing habitats and what measures might maintain or improve growth conditions and survival.

  12. Growth of juvenile steelhead Oncorhynchus mykiss under size-selective pressure limited by seasonal bioenergetic and environmental constraints.

    PubMed

    Thompson, J N; Beauchamp, D A

    2016-09-01

    Increased freshwater growth of juvenile steelhead Oncorhynchus mykiss improved survival to smolt and adult stages, thus prompting an examination of factors affecting growth during critical periods that influenced survival through subsequent life stages. For three tributaries with contrasting thermal regimes, a bioenergetics model was used to evaluate how feeding rate and energy density of prey influenced seasonal growth and stage-specific survival of juvenile O. mykiss. Sensitivity analysis examined target levels for feeding rate and energy density of prey during the growing season that improved survival to the smolt and adult stages in each tributary. Simulated daily growth was greatest during warmer months (1 July to 30 September), whereas substantial body mass was lost during cooler months (1 December to 31 March). Incremental increases in annual feeding rate or energy density of prey during summer broadened the temperature range at which faster growth occurred and increased the growth of the average juvenile to match those that survived to smolt and adult stages. Survival to later life stages could be improved by increasing feeding rate or energy density of the diet during summer months, when warmer water temperatures accommodated increased growth potential. Higher growth during the summer period in each tributary could improve resiliency during subsequent colder periods that lead to metabolic stress and weight loss. As growth and corresponding survival rates in fresh water are altered by shifting abiotic regimes, it will be increasingly important for fisheries managers to better understand the mechanisms affecting growth limitations in rearing habitats and what measures might maintain or improve growth conditions and survival. © 2016 The Fisheries Society of the British Isles.

  13. Monitor and Protect Wigwam River Bull Trout for Koocanusa Reservoir; White River Bull Trout Enumeration Project Summary, Progress Report 2003.

    SciTech Connect

    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 indexmore » 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

  14. Kootenai River Fisheries Investigations; Rainbow and Bull Trout Recruitment, 2003-2004 Annual Report.

    SciTech Connect

    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 juvenilemore » 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

  15. Comparison of prehatch C-start responses in rainbow trout and lake trout embryos by means of a tactile stimulus test

    USGS Publications Warehouse

    Wright, P.J.; Noltie, Douglas B.; Tillitt, D.E.

    2003-01-01

    The C-start in teleost fishes, a type of startle response, mediates the ability to respond to abrupt, unexpected stimuli and is characterized by a short-latency, C-type fast start acceleration. In prehatch fish embryos, the C-start appears necessary for mechanical breakdown of the egg chorion and successful hatching by way of increased embryo movement and distribution of the hatching enzymes. In later stages, the C-start plays an important role in predator avoidance. Using tactile stimulation, we evaluated the C-start response in rainbow trout Oncorhynchus mykiss at 170 degree-days, when 6.6% of embryos exhibited C-starts, and lake trout Salvelinus namaycush embryos at 320 degree-days, when 23% of embryos exhibited C-starts. Triplicate groups of embryos were later tested at three developmental stages: early (220 and 360 degree-days for rainbow trout and lake trout, respectively), middle (260 and 480 degree-days, respectively), and late (320 and 560 degree-days, respectively). The proportion of trout embryos exhibiting C-start increased through time, such that 100% had responded by the late stage, just prior to hatching. C-starts could be obtained by repeated stimulation, and the relative activity of the embryos (based on the number of flexures per stimulus) also increased over time. Rainbow trout and lake trout showed very similar C-start responses at parallel developmental stages, and these patterns of response were similar to those reported in other fish species.

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

    USGS Publications Warehouse

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

    1992-01-01

    Attempts to reestablish self-sustaining stocks of lake trout (Salvelinus namaycush) in the lower four Great Lakes, where the species was extinguished in the 1950s and 1960s, have been largely unsuccessful. To avoid many of the problems believed to be contributing to this failure, the fishery management community recently established several sanctuaries in the offshore waters of the Great Lakes where the development and protection of self-sustaining stocks of lake trout would be a primary management objective. One of these, the Six Fathom Bank-Yankee Reef sanctuary, was created in the south-central portion of Lake Huron. This sanctuary covers 168,000 ha and includes the shallower portions of the Six Fathom and Ipperwash scarps, which are major bathymetric features in the southern half of the lake. Historical accounts describe Six Fathom Bank as the most important lake trout spawning ground in the lake. Here we present the results of lake bed surveys conducted in the sanctuary with side-scan sonar, underwater videocamera systems, and a small research submarine. Our observations of the lake bed are consistent with what is known of the bedrock stratigraphy, glacial history, and karst geomorphology of the Lake Huron basin. Most of the loose rock we found seemed to be derived from local carbonate bedrock formations, although non-carbonate rock probably from Precambrian sources to the north was also present in some areas. Much of the bedrock and loose rock displayed karst solution features described for the Bruce Peninsula on the Ontario shoreline. Our surveys revealed substantial areas of lake bed at water depths of 20–36 m that resembled suitable spawning and fry production habitat for the shallow-water strains of lake trout that are the focus of the rehabilitation effort. Low mid-lake nutrient levels documented recently by others and the extremely high abundance of Mysis relicta (an important item in the diet of young lake trout) that we documented on Yankee Reef

  17. Evaluation of angler effort and harvest of rainbow trout (Oncorhynchus mykiss), Lake Scanewa, Washington, 2010

    USGS Publications Warehouse

    Liedtke, Theresa L.; Kock, Tobias J.; Ekstrom, Brian K.; Tomka, Ryan G.; Rondorf, Dennis W.

    2011-01-01

    A creel evaluation was conducted in Lake Scanewa, a reservoir on the Cowlitz River, to monitor catch rates of rainbow trout (Oncorhynchus mykiss) and determine if the trout fishery was having negative impacts on juvenile anadromous salmon (Oncorhynchus spp.) in the system. The trout fishery, which is supported by releases of 20,000 fish (2 fish per pound) per year from June to August, was developed to mitigate for the construction of the Cowlitz Falls Dam in 1994. The trout fishery has a target catch rate of at least 0.50 fish per hour. Interviews with 1,214 anglers during the creel evaluation found that most anglers targeted rainbow trout (52 percent) or Chinook and coho salmon (48 percent). The interviewed anglers caught a total of 1,866 fish, most of which were rainbow trout (1,213 fish; 78 percent) or coho salmon (311 fish; 20 percent). We estimated that anglers spent 17,365 hours fishing in Lake Scanewa from June to November 2010. Catch rates for boat anglers (1.39 fish per hour) exceeded the 0.50 fish per hour target, whereas catch rates for shore anglers (0.35 fish per hour) fell short of the goal. The combined catch rates for all trout anglers in the reservoir were 0.96 fish per hour. We estimated that anglers harvested 7,584 (95 percent confidence interval = 2,795-12,372 fish) rainbow trout during the study period and boat anglers caught more fish than shore anglers (5,975 and 1,609 fish, respectively). This estimate suggests that more than 12,000 of the 20,000 rainbow trout released into Lake Scanewa during 2010 were not harvested, and could negatively impact juvenile salmon in the reservoir through predation or competition. We examined 1,236 stomach samples from rainbow trout and found that 2.1 percent (26 fish) of these samples contained juvenile fish. Large trout (greater than 300 millimeters) had a higher incidence of predation than small trout (less than 300 millimeters; 8.50 and 0.06 percent, respectively). A total of 39 fish were found in rainbow

  18. Lake trout (Salvelinus namaycush) populations in Lake Superior and their restoration in 1959-1993

    USGS Publications Warehouse

    Hansen, Michael J.; Peck, James W.; Schorfhaar, Richard G.; Selgeby, James H.; Schreiner, Donald R.; Schram, Stephen T.; Swanson, Bruce L.; MacCallum, Wayne R.; Burnham-Curtis, Mary K.; Curtis, Gary L.; Heinrich, John W.; Young, Robert J.

    1995-01-01

    Naturally-reproducing populations of lake trout (Salvelinus namaycush) have been reestablished in most of Lake Superior, but have not been restored to 1929-1943 average abundance. Progress toward lake trout restoration in Lake Superior is described, management actions are reviewed, and the effectiveness of those actions is evaluated; especially stocking lake trout as a tool for building spawning stocks, and subsequently, populations of wild recruits. Widespread destruction of lake trout stocks in the 1950s due to an intense fishery and sea lamprey (Petromyzon marinus) predation resulted in lower overall phenotypic diversity than was previously present. Stocking of yearling lake trout, begun in the 1950s, produced high densities of spawners that reproduced wherever inshore spawning habitat was widespread. Sea lampreys were greatly reduced, beginning in 1961, using selective chemical toxicants and barrier dams, but continue to exert substantial mortality. Fishery regulation was least effective in Wisconsin, where excessive gillnet effort caused high by-catch of lake trout until 1991, and in eastern Michigan, where lake trout restoration was deferred in favor of a tribal fishery for lake whitefish (Coregonus clupeaformis) in 1985. Restoration of stocks was quicker in offshore areas where remnant wild lake trout survived and fishing intensity was low, and was slower in inshore areas where stocked lake trout reproduced successfully and fishing intensity was high. Inshore stocks of wild lake trout are currently about 61 % of historic abundance in Michigan and 53% in Wisconsin. Direct comparison of modern and historic abundances of inshore lake trout stocks in Minnesota and Ontario is impossible due to lack of historic stock assessment data. Stocks in Minnesota are less abundant at present than in Michigan or Wisconsin, and stocks in Ontario are similar to those in Michigan. Further progress in stock recovery can only be achieved if sea lampreys are depressed and if

  19. Relying on fin erosion to identify hatchery-reared brown trout in a Tennessee river

    USGS Publications Warehouse

    Meerbeek, Jonathan R.; Bettoli, Phillip William

    2012-01-01

    Hatchery-induced fin erosion can be used to identify recently stocked catchable-size brown trout Salmo trutta during annual surveys to qualitatively estimate contributions to a fishery. However, little is known about the longevity of this mark and its effectiveness as a short-term (≤ 1 year) mass-marking technique. We evaluated hatchery-induced pectoral fin erosion as a mass-marking technique for short-term stocking evaluations by stocking microtagged brown trout in a tailwater and repeatedly sampling those fish to observe and measure their pectoral fins. At Dale Hollow National Fish Hatchery, 99.1% (228 of 230) of microtagged brown trout in outdoor concrete raceways had eroded pectoral fins 1 d prior to stocking. Between 34 and 68 microtagged and 26-35 wild brown trout were collected during eight subsequent electrofishing samples. In a blind test based on visual examination of pectoral fins at up to 322 d poststocking, one observer correctly identified 91.7% to 100.0% (mean of 96.9%) of microtagged brown trout prior to checking for microtags. In the laboratory, pectoral fin length and width measurements were recorded to statistically compare the fin measurements of wild and microtagged hatchery brown trout. With only one exception, all pectoral fin measurements on each date averaged significantly larger for wild trout than for microtagged brown trout. Based on the number of pectoral fin measurements falling below 95% prediction intervals, 93.7% (148 of 158) of microtagged trout were correctly identified as hatchery fish based on regression models up to 160 d poststocking. Only 72.2% (70 of 97) of microtagged trout were identified correctly after 160 d based on pectoral fin measurements and the regression models. We concluded that visual examination of pectoral fin erosion was a very effective way to identify stocked brown trout for up to 322 d poststocking.

  20. Growth performance, fillet quality, and reproductive maturity of rainbow trout (Oncorhynchus mykiss) cultured to 5 kilograms within freshwater recirculating systems

    USDA-ARS?s Scientific Manuscript database

    Rainbow trout are commonly cultured within aquaculture systems to one pound or less and marketed as pan-sized fillets. Production of larger rainbow trout provides a distinguishable product. Research that describes the growth performance and fillet quality of large rainbow trout is limited, particula...

  1. HIGA: A Running History Information Guided Genetic Algorithm for Protein-Ligand Docking.

    PubMed

    Guan, Boxin; Zhang, Changsheng; Zhao, Yuhai

    2017-12-15

    Protein-ligand docking is an essential part of computer-aided drug design, and it identifies the binding patterns of proteins and ligands by computer simulation. Though Lamarckian genetic algorithm (LGA) has demonstrated excellent performance in terms of protein-ligand docking problems, it can not memorize the history information that it has accessed, rendering it effort-consuming to discover some promising solutions. This article illustrates a novel optimization algorithm (HIGA), which is based on LGA for solving the protein-ligand docking problems with an aim to overcome the drawback mentioned above. A running history information guided model, which includes CE crossover, ED mutation, and BSP tree, is applied in the method. The novel algorithm is more efficient to find the lowest energy of protein-ligand docking. We evaluate the performance of HIGA in comparison with GA, LGA, EDGA, CEPGA, SODOCK, and ABC, the results of which indicate that HIGA outperforms other search algorithms.

  2. Short-duration electrical immobilization of lake trout

    USGS Publications Warehouse

    Gaikowski, Mark P.; Gingerich, William H.; Gutreuter, Steve

    2001-01-01

    Chemical anesthetics induce stress responses, and most leave residues in fish tissues that require a certain withdrawal time before the animal can be released into the environment. Therefore, alternatives are needed in cases when fish must be released immediately, for example, during egg-collecting operations or after implanting elastomer tags. To evaluate pulsed direct current as an alternative method of immobilization, individual lake trout Salvelinus namaycush were electrically immobilized using various pulsed-DC voltage gradients and shock durations. Duration of opercular recovery and narcosis were measured for individual fish. Fish were euthanized 24 h after electrical immobilization and processed for lateral radiograph analysis and assessment of perivertebral hemorrhaging by dissection. Survival of lake trout after electrical immobilization at 0.6 V/cm for 30 or 40 s or 0.8 V/cm for 5 or 15 s was monitored for 81 or 84 d after immobilization. Mean narcosis duration increased with voltage gradient and shock duration. Larger fish had longer periods of narcosis at the same combination of voltage gradient and shock duration. Radiological evaluation indicated that 9 of 28 fish in the oldest age-class tested had detectable injuries of the vertebral column, but all but one were in the lowest injury category. Although vertebral column injuries were observed in most small fish, the majority of vertebral column injuries were minor compressions involving two to seven vertebrae. Of the 82 lake trout electrically immobilized to assess long-term survival, only 5 died (6%). Our data suggest that lake trout could be electrically immobilized for a sufficient period to allow field workers to collect length and weight data and implant visible implant tags or colored elastomer tags. The technique we used, however, is probably not appropriate for procedures that require immobilization for more than 2a??3 min.

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

    USGS Publications Warehouse

    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.

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

    USGS Publications Warehouse

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

    2016-01-01

    Developing fishing regulations for previously unexploited populations presents numerous challenges, many of which stem from a scarcity of baseline information about abundance, population productivity, and expected angling pressure. We used simulation models to test the effect of six management strategies (catch and release; trophy, minimum, and maximum length limits; and protected and exploited slot length limits) on an unexploited population of Lake Trout Salvelinus namaycush in Follensby Pond, a 393-ha lake located in New York State’s Adirondack Park. We combined field and literature data and mark–recapture abundance estimates to parameterize an age-structured population model and used the model to assess the effects of each management strategy on abundance, catch per unit effort (CPUE), and harvest over a range of angler effort (0–2,000 angler-days/year). Lake Trout density (3.5 fish/ha for fish ≥ age 13, the estimated age at maturity) was similar to densities observed in other unexploited systems, but growth rate was relatively slow. Maximum harvest occurred at levels of effort ≤ 1,000 angler-days/year in all the scenarios considered. Regulations that permitted harvest of large postmaturation fish, such as New York’s standard Lake Trout minimum size limit or a trophy size limit, resulted in low harvest and high angler CPUE. Regulations that permitted harvest of small and sometimes immature fish, such as a protected slot or maximum size limit, allowed high harvest but resulted in low angler CPUE and produced rapid declines in harvest with increases in effort beyond the effort consistent with maximum yield. Management agencies can use these results to match regulations to management goals and to assess the risks of different management options for unexploited Lake Trout populations and other fish species with similar life history traits.

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

    USGS Publications Warehouse

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

    2011-01-01

    Restoration stocking of hatchery-reared lake trout Salvelinus namaycush has occurred in Lake Ontario since 1973. In U.S. waters, fish stocked through 1990 survived well and built a large adult population. Survival of yearlings stocked from shore declined during 1990–1995, and adult numbers fell during 1998–2005. Offshore stocking of lake trout was initiated in the late 1990s in response to its successful mitigation of predation losses to double-crested cormorants Phalacrocorax auritus and the results of earlier studies that suggested it would enhance survival in some cases. The current study was designed to test the relative effectiveness of three stocking methods at a time when poststocking survival for lake trout was quite low and losses due to fish predators was a suspected factor. The stocking methods tested during 2000–2002 included May offshore, May onshore, and June onshore. Visual observations during nearshore stockings and hydroacoustic observations of offshore stockings indicated that release methods were not a direct cause of fish mortality. Experimental stockings were replicated for 3 years at one site in the southwest and for 2 years at one site in the southeast. Offshore releases used a landing craft to transport hatchery trucks from 3 to 6 km offshore out to 55–60-m-deep water. For the southwest site, offshore stocking significantly enhanced poststocking survival. Among the three methods, survival ratios were 1.74 : 1.00 : 1.02 (May offshore : May onshore : June onshore). Although not statistically significant owing to the small samples, the trends were similar for the southeast site, with survival ratios of 1.67 : 1.00 : 0.72. Consistent trends across years and sites indicated that offshore stocking of yearling lake trout during 2000–2002 provided nearly a twofold enhancement in survival; however, this increase does not appear to be great enough to achieve the 12-fold enhancement necessary to return population abundance to restoration

  6. A hematopoietic virus disease of rainbow trout and sockeye salmon

    USGS Publications Warehouse

    Amend, Donald F.; Yasutake, William T.; Mead, Robert W.

    1969-01-01

    A previously undescribed virus disease epizootic of hatchery rainbow trout (Salmo gairdneri) in British Columbia, Canada is presented. In the same locality, a similar virus disease was experienced among hatchery sockeye salmon (Oncorhynchus nerka). Typical symptoms included flashing, fecal casts, hemorrhagic areas at the base of fins, and petechial hemorrhages on the visceral fat and membranes in the abdominal cavity. Histopathologic changes were typified by extensive degeneration and necrosis in the hematopoietic tissues of the kidney and spleen. A virus was isolated from both species of fish on tissue culture and the viruses showed cross-infectivity. Based upon the pathological changes in the hematopoietic tissue and the demonstration of a vital infection, a tentative descriptive name was designated Infectious Hematopoietic Necrosis. The isolated viruses were distinctly different from the infectious pancreatic necrosis or viral hemorrhagic septicemia viruses of trout, but did show similarities to the Oregon sockeye and Sacramento River chinook viruses. Positive identification awaits further tests. The significance of these observations is the reporting of a new viral disease of rainbow trout and the extension of the geographic range of sockeye salmon viruses.

  7. Energy budget for yearling lake trout, Salvelinus namaycush

    USGS Publications Warehouse

    Rottiers, Donald V.

    1993-01-01

    Components of the energy budget of yearling lake trout (Salvelinus namaycush) were derived from data gathered in laboratory growth and metabolism studies; values for energy lost as waste were estimated with previously published equations. Because the total caloric value of food consumed by experimental lake trout was significantly different during the two years in which the studies were done, separate annual energy budgets were formulated. The gross conversion efficiency in yearling lake trout fed ad libitum rations of alewives at 10A?C was 26.6% to 41%. The distribution of energy with temperature was similar for each component of the energy budget. Highest conversion efficiencies were observed in fish fed less than ad libitum rations; fish fed an amount of food equivalent to about 4% of their body weight at 10A?C had a conversion efficiency of 33% to 45.1%. Physiologically useful energy was 76.1-80.1% of the total energy consumed. Estimated growth for age-I and -II lake fish was near that observed for laboratory fish held at lake temperatures and fed reduced rations.

  8. Development and evaluation of 200 novel SNP assays for population genetic studies of westslope cutthroat trout and genetic identification of related taxa

    Treesearch

    N. R. Campbell; S. J. Amish; V. L. Prichard; K. M. McKelvey; M. K. Young; M. K. Schwartz; J. C. Garza; G. Luikart; S. R. Narum

    2012-01-01

    DNA sequence data were collected and screened for single nucleotide polymorphisms (SNPs) in westslope cutthroat trout (Oncorhynchus clarki lewisi) and also for substitutions that could be used to genetically discriminate rainbow trout (O. mykiss) and cutthroat trout, as well as several cutthroat trout subspecies. In total, 260 expressed sequence tag-derived loci were...

  9. Influence of a weak field of pulsed DC electricity on the behavior and incidence of injury in adult Steelhead and Pacific Lamprey

    USGS Publications Warehouse

    Mesa, Matthew G.; Copeland, Elizabeth S.

    2009-01-01

    Predation by pinnipeds, such as California sea lions Zalophus californianus, Pacific harbor seals Phoca vitulina, and Stellar sea lions Eumetopias jubatus on adult Pacific salmon Oncorhynchus spp in the lower Columbia River has become a serious concern for fishery managers trying to conserve and restore runs of threatened and endangered fish. As a result, Smith-Root, Incorporated (SRI; Vancouver, Washington), manufacturers of electrofishing and closely-related equipment, proposed a project to evaluate the potential of an electrical barrier to deter marine mammals and reduce the amount of predation on adult salmonids (SRI 2007). The objectives of their work were to develop, deploy, and evaluate a passive, integrated sonar and electric barrier that would selectively inhibit the upstream movements of marine mammals and reduce predation, but would not injure pinnipeds or impact anadromous fish migrations. However, before such a device could be deployed in the field, concerns by regional fishery managers about the potential effects of such a device on the migratory behavior of Pacific salmon, steelhead O. mykiss, Pacific lampreys Entoshpenus tridentata, and white sturgeon Acipenser transmontanus, needed to be addressed. In this report, we describe the results of laboratory research designed to evaluate the effects of prototype electric barriers on adult steelhead and Pacific lampreys.

  10. Behavior patterns and fates of adult steelhead, Chinook salmon, and coho salmon released into the upper Cowlitz River Basin, 2005–09 and 2012, Washington

    USGS Publications Warehouse

    Kock, Tobias J.; Ekstrom, Brian K.; Liedtke, Theresa L.; Serl, John D.; Kohn, Mike

    2016-08-26

    A multiyear radiotelemetry evaluation was conducted to monitor adult steelhead (Oncorhynchus mykiss), Chinook salmon (O. tshawytscha), and coho salmon (O. kisutch) behavior and movement patterns in the upper Cowlitz River Basin. Volitional passage to this area was eliminated by dam construction in the mid-1960s, and a reintroduction program began in the mid-1990s. Fish are transported around the dams using a trap-and-haul program, and adult release sites are located in Lake Scanewa, the uppermost reservoir in the system, and in the Cowlitz and Cispus Rivers. Our goal was to estimate the proportion of tagged fish that fell back downstream of Cowlitz Falls Dam before the spawning period and to determine the proportion that were present in the Cowlitz and Cispus Rivers during the spawning period. Fallback is important because Cowlitz Falls Dam does not have upstream fish passage, so fish that pass the dam are unable to move back upstream and spawn. A total of 2,051 steelhead and salmon were tagged for the study, which was conducted during 2005–09 and 2012, and 173 (8.4 percent) of these regurgitated their transmitter prior to, or shortly after release. Once these fish were removed from the dataset, the final number of fish that was monitored totaled 1,878 fish, including 647 steelhead, 770 Chinook salmon, and 461 coho salmon.Hatchery-origin (HOR) and natural-origin (NOR) steelhead, Chinook salmon, and coho salmon behaved differently following release into Lake Scanewa. Detection records showed that the percentage of HOR fish that moved upstream and entered the Cowlitz River or Cispus River after release was relatively low (steelhead = 38 percent; Chinook salmon = 67 percent; coho salmon = 41 percent) compared to NOR fish (steelhead = 84 percent; Chinook salmon = 82 percent; coho salmon = 76 percent). The elapsed time from release to river entry was significantly lower for NOR fish than for HOR fish for all three species. Tagged fish entered the Cowlitz River in

  11. 75 FR 29316 - Marine Mammals; File No. 13599

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-25

    ... under NMFS jurisdiction including Chinook (Oncorhynchus tshawytscha), chum (Oncorhynchus keta), coho (Oncorhynchus kisutch) and sockeye (Oncorhynchus nerka) salmon, steelhead trout (Oncorhynchus mykiss), green...

  12. 75 FR 52964 - Revision of Information Collection; Non-Use Valuation Survey, Klamath Basin

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-30

    ... revision. The Klamath River provides habitat for fall and spring run Chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), steelhead trout (Oncorhynchus mykiss), green sturgeon...

  13. 78 FR 32622 - Endangered Species; File Nos. 17557 and 17273

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-31

    ... white (Haliotis sorenseni) abalone, chinook (Oncorhynchus tshawytscha), chum (Oncorhynchus keta), coho (Oncorhynchus kisutch) and sockeye (Oncorhynchus nerka) salmon, steelhead trout (Oncorhynchus mykiss), and...

  14. Behavior and dam passage of juvenile Chinook salmon and juvenile steelhead at Detroit Reservoir and Dam, Oregon, March 2012-February 2013

    USGS Publications Warehouse

    Beeman, John W.; Hansel, Hal C.; Hansen, Amy C.; Evans, Scott D.; Haner, Philip V.; Hatton, Tyson W.; Kofoot, Eric E.; Sprando, Jamie M.; Smith, Collin D.

    2014-01-01

    The in-reservoir movements and dam passage of individual juvenile Chinook salmon (Oncorhynchus tshawytscha) and juvenile steelhead (Oncorhynchus mykiss) were studied at Detroit Reservoir and Dam, near Detroit, Oregon, during 2012 and 2013. The goal of the study was to provide data to inform decisions about future downstream passage alternatives and factors affecting downstream passage rates with the existing dam configuration. In 2012, 468 juvenile Chinook salmon and 200 juvenile steelhead were tagged and released during a 3-month period in the spring, and another 514 juvenile Chinook salmon were tagged and released during a 3-month period in the fall. The fish were surgically implanted with a small acoustic transmitter with an expected life of about 3 months and a passive integrated transponder tag with an indefinite life, and were released into the two main tributaries several kilometers upstream of the reservoir. Juvenile Chinook salmon migrated from the release sites to the reservoir in a greater proportion than juvenile steelhead, but once in the reservoir, juvenile steelhead migrated to the forebay faster and had a higher dam passage rate than juvenile Chinook salmon. The routes available for passing water and fish varied throughout the year, with low reservoir elevations in winter and high reservoir elevations in summer in accordance with the flood-control purpose of the dam. Most dam passage was through the spillway during the spring and summer, when the reservoir elevation was high and the spillway and powerhouse were the most common routes in operation, and via the powerhouse during the fall and winter period, when the reservoir elevation was low and the regulating outlet and powerhouse were the most common routes in operation. Few tagged fish passed when the powerhouse was the only route in operation. Dam passage rates during the spring and summer were greatest at night, increased with dam discharge, and were greater when water was passed freely over the

  15. Assessing the consequences of nonnative trout in headwater ecosystems in western North America

    Treesearch

    Jason B. Dunham; David S. Pilliod; Michael K. Young

    2004-01-01

    Intentional introductions of nonnative trout into headwater lakes and streams can have numerous effects on the receiving ecosystems, potentially threatening native species and disrupting key ecological processes. In this perspective, we focus on seven key issues for assessing the biological and economic consequences of nonnative trout in headwater ecosystems: (1)...

  16. An environmental DNA marker for detecting nonnative brown trout (Salmo trutta)

    Treesearch

    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...

  17. Brook trout movement during and after recolonization of a naturally defaunated stream reach

    Treesearch

    Craig N. Roghair; C. Andrew Dolloff

    2005-01-01

    In june 1995 a debris flow associated with a massive streamwide flood completely eliminated brook trout Salvelinus fontinalis from the lower 1.9 km of the Staunton River in Shenandoah National Park, Virginia. Biannual diver counts revealed that brook trout moved several hundred meters into the debris-flow-affected area each year, resulting in...

  18. Evaluation of long-chain n3 fatty acid content in diploid and triploid rainbow trout

    USDA-ARS?s Scientific Manuscript database

    Intake of long chain n3 fatty acids (LCn3), eicosapentaenoic acid (EPA; 20:5 n3) and docosahexaenoic acid (DHA; 22:6 n3), is associated with reduced cardiovascular disease. There is growing interest in farmed fish like rainbow trout, Oncorhynchus mykiss, as sources of LCn3. The trout industry raises...

  19. Ecology and population status of trout-perch (Percopsis omiscomaycus) in western Lake Erie

    USGS Publications Warehouse

    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.

  20. Aquatic and terrestrial invertebrate drift in southern Appalachian Mountain streams: implications for trout food resources

    Treesearch

    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...

  1. Sensory analysis of rainbow trout, oncorhynchus mykiss, fed enriched black soldier fly prepupae, hermetia illucens

    USDA-ARS?s Scientific Manuscript database

    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...

  2. Population-level analysis and validation of an individual-based cutthroat trout model

    Treesearch

    Steven F. Railsback; Bret C. Harvey; Roland H. Lamberson; Derek E. Lee; Claasen Nathan J.; Shuzo Yoshihara

    2002-01-01

    Abstract - An individual-based model of stream trout is analyzed by testing its ability to reproduce patterns of population-level behavior observed in real trout: (1) "self-thinning," a negative power relation between weight and abundance; (2) a "critical period" of density-dependent mortality in young-of-the-year; (3) high and age-speci...

  3. Performance of Yellowstone and Snake River Cutthroat Trout Fry Fed Seven Different Diets.

    USDA-ARS?s Scientific Manuscript database

    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...

  4. Fatty acid partitioning varies across fillet regions during sexual maturation in female rainbow trout (Oncorhynchus mykiss)

    USDA-ARS?s Scientific Manuscript database

    Rainbow trout (Oncorhynchus mykiss) are commonly reared as diploids (2N, two sets of chromosomes) or triploids (3N, three sets of chromosomes). Sexual maturation in 2N has negative effects on production efficiency, nutrient retention, and fillet quality. On the other hand, 3N female rainbow trout ...

  5. Prey selection by trout in a spring-fed stream:terrestrial versus aquatic invertebrates

    USGS Publications Warehouse

    Laudon, M.C.; Vondracek, B.; Zimmerman, J.K.H.

    2005-01-01

    We evaluated the prey sources that contributed to the diets of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) in Valley Creek, Minnesota during the summer of 2003. We collected drift before dawn and in the afternoon on five dates in June, July, and August 2003 in three sequential riffles. Immediately following drift sampling, we collected brown and rainbow trout, 13-20 cm in length, in pools immediately below the riffles where drift was collected. Terrestrial invertebrates numerically comprised about 3% of the drift across times and dates but made up approximately 10% by number of the overall diet of brown and rainbow trout. Trout were size-selective, preferring larger invertebrates by both length (7.0-12.9 mm) and biomass. Gammarus pseudolimnaeus made up about 75% of the diet of brown trout and about 60% of the diet of rainbow trout based on biomass. Diet overlap was >60% for both trout in relation to total individuals, length, and biomass of invertebrate prey.

  6. Virulence and molecular variation of Flavobacterium columnare affecting rainbow trout in ID, USA

    USDA-ARS?s Scientific Manuscript database

    Columnaris disease is an emerging problem in the rainbow trout (Oncorhychus mykiss) aquaculture industry of Idaho. The epidemiology of this pathogen in the area, and for rainbow trout, is all isolates taken from disease outbreaks are genomovar I and similar based on basic typing protocols. Virulence...

  7. Use of naturally occurring mercury to determine the importance of cutthroat trout to Yellowstone grizzly bears

    USGS Publications Warehouse

    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.

  8. Local-Habitat, Watershed, and Biotic Features Associated with Bull Trout Occurrence in Montana Streams

    Treesearch

    C.F. Rich; T.E. McMahon; B.E. Rieman; W.L. Thompson

    2003-01-01

    We evaluated the association of local-habitat features, large-scale watershed factors, the presence of nonnative brook trout Salvelinus fontinalis, and connectivity to neighboring populations with patterns of occurrence of threatened bull trout S. confluentus in 112 first-order to fourthorder streams in the Bitterroot River drainage in western Montana. Species presence...

  9. Larval long-toed salamanders incur nonconsumptive effects in the presence of nonnative trout

    USGS Publications Warehouse

    Kenison, Erin K.; Litt, Andrea R.; Pilliod, David S.; 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.

  10. Effects of phytoestrogens on growth-related and lipogenic genes in rainbow trout (Oncorhynchus mykiss)

    USDA-ARS?s Scientific Manuscript database

    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...

  11. Effects of cooking techniques on fatty acid and oxylipin content of farmed rainbow trout (Oncorhynchus mykiss)

    USDA-ARS?s Scientific Manuscript database

    Rainbow trout is an excellent source of long chain omega-3 polyunsaturated fatty acids (PUFA) which have beneficial health effects. We determined the fatty acid and oxylipin content of 2-year old rainbow trout fillets that were raw, baked, broiled, microwaved, or pan-fried in corn (CO), canola (CaO...

  12. Individual-based model formulation for cutthroat trout, Little Jones Creek, California

    Treesearch

    Steven F. Railsback; Bret C. Harvey

    2001-01-01

    This report contains the detailed formulation of an individual-based model (IBM) of cutthroat trout developed for three study sites on Little Jones Creek, Del Norte County, in northwestern California. The model was designed to support research on relations between habitat and fish population dynamics, the importance of small tributaries to trout populations, and the...

  13. Biology, population structure, and estimated forage requirements of lake trout in Lake Michigan

    USGS Publications Warehouse

    Eck, Gary W.; Wells, LaRue

    1983-01-01

    Data collected during successive years (1971-79) of sampling lake trout (Salvelinus namaycush) in Lake Michigan were used to develop statistics on lake trout growth, maturity, and mortality, and to quantify seasonal lake trout food and food availability. These statistics were then combined with data on lake trout year-class strengths and age-specific food conversion efficiencies to compute production and forage fish consumption by lake trout in Lake Michigan during the 1979 growing season (i.e., 15 May-1 December). An estimated standing stock of 1,486 metric tons (t) at the beginning of the growing season produced an estimated 1,129 t of fish flesh during the period. The lake trout consumed an estimated 3,037 t of forage fish, to which alewives (Alosa pseudoharengus) contributed about 71%, rainbow smelt (Osmerus mordax) 18%, and slimy sculpins (Cottus cognatus) 11%. Seasonal changes in bathymetric distributions of lake trout with respect to those of forage fish of a suitable size for prey were major determinants of the size and species compositions of fish in the seasonal diet of lake trout.

  14. A hedonic price analysis of the outfitter market for trout fishing in the Rocky Mountain West

    Treesearch

    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...

  15. Indirect effects of introduced trout on Cascades frogs (Rana cascadae) via shared aquatic prey

    Treesearch

    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)

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

    Treesearch

    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...