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Sample records for steelhead trout production

  1. Compendium of Low-Cost Pacific Salmon and Steelhead Trout Production Facilities and Practices in the Pacific Northwest.

    Energy Technology Data Exchange (ETDEWEB)

    Senn, Harry G.

    1984-09-01

    The purpose was to research low capital cost salmon and steelhead trout production facilities and identify those that conform with management goals for the Columbia Basin. The species considered were chinook salmon (Oncorhynchus tshawytscha), coho salmon (O. kisutch), sockeye salmon (O. nerka), and steelhead trout (Salmo gairdneri). This report provides a comprehensive listing of the facilities, techniques, and equipment used in artificial production in the Pacific Northwest. (ACR)

  2. Evaluation and monitoring of wild/natural steelhead trout production: project progress report, 1996; ANNUAL

    International Nuclear Information System (INIS)

    Leth, Brian D.; Holubetz, Terry; Nemeth, Doug

    2000-01-01

    This project was initiated to provide additional, and more definitive, information regarding wild steelhead Oncorhynchus mykiss populations in Idaho. Important streams for wild steelhead production were identified and selected for monitoring. Monitoring activities employed among streams varied, but generally included: aerial redd counts, placement of adult weirs, enumeration of juveniles through mask and snorkel counts, and emigrant trapping. This report details activities during the 1996 field season

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

    Science.gov (United States)

    Buehrens, T.W.; Glasgow, J.; Ostberg, Carl O.; Quinn, T.P.

    2013-01-01

    Native Coastal Cutthroat Trout Oncorhynchus clarkii clarkii and Coastal Steelhead O. mykiss irideus hybridize naturally in watersheds of the Pacific Northwest yet maintain species integrity. Partial reproductive isolation due to differences in spawning habitat may limit hybridization between these species, but this process is poorly understood. We used a riverscape approach to determine the spatial distribution of spawning habitats used by native Coastal Cutthroat Trout and Steelhead as evidenced by the distribution of recently emerged fry. Molecular genetic markers were used to classify individuals as pure species or hybrids, and individuals were assigned to age-classes based on length. Fish and physical habitat data were collected in a spatially continuous framework to assess the relationship between habitat and watershed features and the spatial distribution of parental species and hybrids. Sampling occurred in 35 reaches from tidewaters to headwaters in a small (20 km2) coastal watershed in Washington State. Cutthroat, Steelhead, and hybrid trout accounted for 35%, 42%, and 23% of the fish collected, respectively. Strong segregation of spawning areas between Coastal Cutthroat Trout and Steelhead was evidenced by the distribution of age-0 trout. Cutthroat Trout were located farther upstream and in smaller tributaries than Steelhead were. The best predictor of species occurrence at a site was the drainage area of the watershed that contributed to the site. This area was positively correlated with the occurrence of age-0 Steelhead and negatively with the presence of Cutthroat Trout, whereas hybrids were found in areas occupied by both parental species. A similar pattern was observed in older juveniles of both species but overlap was greater, suggesting substantial dispersal of trout after emergence. Our results offer support for spatial reproductive segregation as a factor limiting hybridization between Steelhead and Coastal Cutthroat Trout.

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

    Science.gov (United States)

    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...

  5. Stock Identification of Columbia River Chinook Salmon and Steelhead Trout, 1986 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Schreck, Carl B.; Li, Hiran W.; Hjort, Randy C.

    1986-08-01

    For the first time genetic similarities among chinook salmon and among steelhead trout stocks of the Columbia River were determined using a holistic approach including analysis of life history, biochemical, body shape and meristic characters. We examined between year differences for each of the stock characteristics and we also correlated the habitat characteristics with the wild stock characteristics. The most important principle for managing stocks of Columbia River chinook salmon and steelhead trout is that geographically proximal stocks tend to be like each other. Run timing and similarity of the stream systems should be taken into account when managing stocks. There are similarities in the classifications derived for chinook salmon and steelhead trout. Steelhead trout or chinook salmon tend to be genetically similar to other steelhead or chinook stocks, respectively, that originate from natal streams that are geographically close, regardless of time of freshwater entry. The primary exception Lo this trend is between stocks of spring and fall chinook in the upper Columbia River where fish with the different run timings are dissimilar, though geographically proximate stocks within a run form are generally very similar. Spring chinook stocks have stronger affinities to other spring chinook stocks that originate in the same side of the Cascade Range than to these Spring chinook stock: spawned on the other side of the Cascade Range. Spring chinook from west of the Cascades are more closely related to fall chinook than they are to spring chinook from east of the Cascades. Summer chinook can be divided into two main groups: (1) populations in the upper Columbia River that smolt as subyearlings and fall chinook stocks; and (2) summer chinook stocks from the Salmon River, Idaho, which smolt as yearlings and are similar to spring chinook stocks from Idaho. Fall chinook appear to comprise one large diverse group that is not easily subdivided into smaller subgroups. In

  6. Stock Identification of Columbia River Chinook Salmon and Steelhead Trout, 1984-1985 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Schreck, Carl B.; Sharpe, Cameron; Li, Hiram W. (Oregon State University, Oregon Cooperative Fishery Research Unit, Corvallis, OR)

    1985-09-21

    Fish were collected from 60 stocks of chinook salmon and 62 stocks of steelhead trout. Electrophoretic analyses were completed on 43 stocks of chinook salmon and 41 stocks of steelhead trout and meristic counts were completed on 43 stocks of chinook and 41 stocks of steelhead. Statistical comparisons between year classes of our electrophoretic data indicate that most enzyme systems are stable over time but some may be dynamic and should be used with caution in our analyses. We also compared neighboring stocks of both spring chinook and steelhead trout. These comparisons were between stocks of the same race from adjacent stream systems and/or hatcheries. Differences in isozyme gene frequencies can be used to estimate genetic segregation between pairs of stocks. Analysis of the chinook data suggests that, as expected, the number of statistically significant differences in isozyme gene frequencies increases as the geographic distance between stocks increases. The results from comparisons between adjacent steelhead stocks were inconclusive and must await final analysis with more data. Cluster analyses using either isozyme gene frequencies or meristic characters both tended to group the chinook and steelhead stocks by geographic areas and by race and both methods resulted in generally similar grouping patterns. However, cluster analyses using isozyme gene frequencies produced more clusters than the analyses using meristic characters probably because of the greater number of electrophoretic characters compared to the number of meristic characters. Heterozygosity values for each stock were computed using the isozyme gene frequencies. The highest heterozygosity values for chinook were observed in summer chinook and the hatchery stocks while the lowest values were observed in the spring chinook and wild stocks. The results of comparisons of heterozygosity values among areas were inconclusive. The steelhead heterozygosity values were higher in the winter stocks than in the

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Underwood, Keith D.

    1995-01-01

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

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

    International Nuclear Information System (INIS)

    Underwood, K.D.; Martin, S.W.; Schuck, M.L.; Scholz, A.T.

    1995-01-01

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

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

    International Nuclear Information System (INIS)

    Underwood, K.D.; Martin, S.W.; Schuck, M.L.; Scholz, A.T.

    1995-01-01

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

  14. Spring outmigration of wild and hatchery chinook salmon and steelhead trout smolts from the Imnaha River: March 1, 1994--June 15, 1994; TOPICAL

    International Nuclear Information System (INIS)

    Ashe, B.L.; Miller, A.C.; Kucera, P.A.; Blenden, M.L.

    1995-01-01

    In 1994, the Nez Perce Tribe began a smolt monitoring study on the Imnaha River in cooperation with the Fish Passage Center (FPC). A rotary screw trap was used to collect emigrating wild and hatchery chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Oncorhynchus mykiss) smolts from March 1 to June 15, 1994. We PIT tagged and released 956 wild chinook salmon, 661 hatchery chinook salmon, 1,432 wild steelhead trout and 2,029 hatchery steelhead trout. Cumulative interrogation rates at mainstem Snake and Columbia River dams were 62.2% for wild chinook salmon, 45.2% for hatchery chinook salmon, 51.3% for wild steelhead trout, and 34.3% for hatchery steelhead trout

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

    Science.gov (United States)

    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.

  16. Spring outmigration of wild and hatchery chinook salmon and steelhead trout smolts from the Imnaha River, Oregon, February 23--June 24, 1996. Annual report 1996

    International Nuclear Information System (INIS)

    Blendon, M.L.; Rocklage, S.J.; Kucera, P.A.

    1997-04-01

    For the third consecutive year, the Nez Perce Tribe, in conjunction with the Fish Passage Center, participated in the smolt monitoring program in the Imnaha River. A rotary screw trap was used to collect emigrating wild and hatchery chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Oncorhynchus mykiss) smolts from February 23 to June 24, 1996. A total of 1,797 wild chinook salmon, 11,896 hatchery chinook salmon, 3,786 wild steelhead trout, and 31,094 hatchery steelhead trout smolts were captured during outmigration studies on the Imnaha River in 1996. Mortality associated with trapping, handling and tagging was low, being 1.4% for wild chinook, 0.18% for hatchery chinook, 0.21% for wild steelhead and 0.28% for hatchery steelhead trout smolts

  17. Spring outmigration of wild and hatchery chinook salmon and steelhead trout smolts from the Imnaha River, Oregon, February 23--June 24, 1996. Annual report 1996; ANNUAL

    International Nuclear Information System (INIS)

    Blendon, M.L.; Rocklage, S.J.; Kucera, P.A.

    1997-01-01

    For the third consecutive year, the Nez Perce Tribe, in conjunction with the Fish Passage Center, participated in the smolt monitoring program in the Imnaha River. A rotary screw trap was used to collect emigrating wild and hatchery chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Oncorhynchus mykiss) smolts from February 23 to June 24, 1996. A total of 1,797 wild chinook salmon, 11,896 hatchery chinook salmon, 3,786 wild steelhead trout, and 31,094 hatchery steelhead trout smolts were captured during outmigration studies on the Imnaha River in 1996. Mortality associated with trapping, handling and tagging was low, being 1.4% for wild chinook, 0.18% for hatchery chinook, 0.21% for wild steelhead and 0.28% for hatchery steelhead trout smolts

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Steven W.

    1992-07-01

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

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Brannon, E.L.; National Science Foundation (U.S.)

    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 cline 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 placed on

  2. Adaptive trade-offs in juvenile salmonid metabolism associated with habitat partitioning between coho salmon and steelhead trout in coastal streams.

    Science.gov (United States)

    Van Leeuwen, Travis E; Rosenfeld, Jordan S; Richards, Jeffrey G

    2011-09-01

    1. Adaptive trade-offs are fundamental to the evolution of diversity and the coexistence of similar taxa and occur when complimentary combinations of traits maximize efficiency of resource exploitation or survival at different points on environmental gradients. 2. Standard metabolic rate (SMR) is a key physiological trait that reflects adaptations to baseline metabolic performance, whereas active metabolism reflects adaptations to variable metabolic output associated with performance related to foraging, predator avoidance, aggressive interactions or migratory movements. Benefits of high SMR and active metabolism may change along a resource (productivity) gradient, indicating that a trade-off exists among active metabolism, resting metabolism and energy intake. 3. We measured and compared SMR, maximal metabolic rate (MMR), aerobic scope (AS), swim performance (UCrit) and growth of juvenile hatchery and wild steelhead and coho salmon held on high- and low-food rations in order to better understand the potential significance of variation in SMR to growth, differentiation between species, and patterns of habitat use along a productivity gradient. 4. We found that differences in SMR, MMR, AS, swim performance and growth rate between steelhead trout and coho salmon were reduced in hatchery-reared fish compared with wild fish. Wild steelhead had a higher MMR, AS, swim performance and growth rate than wild coho, but adaptations between species do not appear to involve differences in SMR or to trade-off increased growth rate against lower swim performance, as commonly observed for high-growth strains. Instead, we hypothesize that wild steelhead may be trading off higher growth rate for lower food consumption efficiency, similar to strategies adopted by anadromous vs. resident brook trout and Atlantic salmon vs. brook trout. This highlights potential differences in food consumption and digestion strategies as cryptic adaptations ecologically differentiating salmonid species

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

    Science.gov (United States)

    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.

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

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    Barry A Berejikian

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  6. Spring outmigration of wild and hatchery chinook salmon and steelhead trout smolts from the Imnaha River, Oregon, February 6, 1995--June 20, 1995

    International Nuclear Information System (INIS)

    Blenden, M.L.; Osborne, R.S.; Kucera, P.A.

    1996-01-01

    For the second consecutive year, the Nez Perce Tribe, in conjunction with the Fish Passage Center, participated in the smolt monitoring program in the Imnaha River. A rotary screw trap was used to collect emigrating wild and hatchery chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Oncorhynchus mykiss) smolts from February 6 to June 20, 1995. We PIT tagged and released 421 wild chinook salmon smolts, 747 hatchery chinook salmon smolts (445 HxW and 302 HxH), 227 wild steelhead trout smolts and 1,296 hatchery steelhead trout smolts. Cumulative interrogation rates at mainstem Snake and Columbia River dams were 78.4% for wild chinook salmon, 58.9% for hatchery chinook salmon (HxW), 56.6% for hatchery chinook salmon (HxH), 76.2% for wild steelhead trout, and 69.2% for hatchery steelhead trout. Peak outmigration of NPT tagged wild Imnaha River chinook salmon smolts occurred from early to mid-May at Lower Granite, Little Goose, and Lower Monumental Dams. Median and 90% passage dates for wild chinook salmon smolts at Lower Granite Dam were May 1 and May 11, respectively. Continuous spill at Lower Granite Dam was initiated on May 3 and lasted for 51 days. The 90% passage date of wild chinook salmon smolts at Lower Granite Dam (May 11) preceded peak Snake River and Lower Granite (June 6) flows by 26 days. Although hatchery chinook salmon exhibited a shorter outmigration period through the Snake River than their wild counterparts, peak arrival for both groups occurred at approximately the same time. Median and 90% passage dates at Lower Granite Dam for other PIT tagged groups were: hatchery chinook salmon (NPT-HxW) - May 2 and May 13; hatchery chinook salmon (FPC-HxH) - May 8 and May 15; wild steelhead trout - May 2 and May 9; and hatchery steelhead trout (NPT and FPC) - May 31 and June 16. Hatchery steelhead trout displayed small peaks in arrival timing at Lower Granite and Little Goose Dams in mid-May to mid-June

  7. Steelhead Supplementation Studies in Idaho Rivers: To evaluate the feasibility of using artificial production to increase natural steelhead populations and to collect baseline life history, genetic, and disease data from natural steelhead populations. 1993 Annual report

    International Nuclear Information System (INIS)

    Byrne, A.

    1996-01-01

    The Steelhead Supplementation Study was designed to evaluate the feasibility of using artificial production to increase natural steelhead Oncorhynchus mykiss populations and to collect baseline life history, genetic, and disease data from natural steelhead populations. To evaluate supplementation, the authors focused their experimental design on post-release survival, reproductive success, long-term fitness, and ecological interactions. They began field experiments in 1993 by outplanting hatchery adults and fingerlings to assess reproductive fitness and long-term survival. They snorkeled eight streams to estimate juvenile steelhead densities, recorded temperatures in 17 streams, and tagged natural steelhead in six streams with Passive Integrated Transponder (PIT) tags

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

    Science.gov (United States)

    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.

  9. Lewis Steelhead Genetics - Lewis River Steelhead Reintroduction

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Rainbow trout and steelhead consist of the same species and often inhabit the similar habitat types within the same watershed. Although their life histories differ...

  10. Assembling a dual purpose TaqMan-based panel of single-nucleotide polymorphism markers in rainbow trout and steelhead (Oncorhynchus mykiss) for association mapping and population genetics analysis

    DEFF Research Database (Denmark)

    Hansen, Mette H H; Young, Sewall; Jørgensen, Hanne Birgitte Hede

    2011-01-01

    We establish a TaqMan-based assay panel for genotyping single-nucleotide polymorphisms in rainbow trout and steelhead (Oncorhynchus mykiss). We develop 22 novel single-nucleotide polymorphism markers based on new steelhead sequence data and on assays from sister taxa. Additionally, we adapt 154 p...

  11. Smolt Monitoring Program, Volume II, Migrational Characteristics of Columbia Basin Salmon and Steelhead Trout, 1986 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Fish Passage Center

    1987-02-01

    Smolt Monitoring Program Annual Report, 1986, Volume I, describes the results of travel time monitoring and other migrational characteristics of yearling and sub-yearling chinook salmon (Oncorhynchus tshawytscha), sockeye salmon (Oncorhynchus nerka), and steelhead trout (Salmo gairdneri). This volume presents the data from Fish Passage Center freeze brands used in the analysis of travel time for Lewiston, Lower Granite, Lower Monumental, Rock Island, McNary, and John Day dams. Summary of data collection procedures and explanation of data listings are presented in conjunction with the mark recapture data. Data for marked fish not presented in this report will be provided upon request. Daily catch statistics (by species), flow, and sample parameters for the smolt monitoring sites, Clearwater, Lewiston, Lower Granite, Lower Monumental, Rock Island, McNary, John Day, and Bonneville also will be provided upon request.

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

    Science.gov (United States)

    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.

  13. 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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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 (...

  16. Migration of steelhead - Genetic basis of migratory tendency and life history plasticity in Oncorhynchus mykiss

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Steelhead and rainbow trout are the same species. However, their life histories diverge - with steelhead undertaking an anadromous life cycle whereas rainbow trout...

  17. Rapid Diagnosis of IHN Virus Infection in Salmon and Steelhead Trout, Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Leong, JoAnn Ching

    1984-12-01

    The main objective for this study was the development of a rapid diagnostic method for IHN virus in fish tissue samples. The rationale for developing new techniques for diagnosing IHNV infection was that present methods were time consuming and dependent on virus neutralization by specific antisera, a reagent that was not readily available or reliable. Fish pathologists required a rapid detection method which was sensitive enough to detect virus strain differences so that they could provide data for effective management decisions in controlling the spread of IHNV. Bonneville Power Administration's (BPA) role in efforts in fish diseases and more generically the protection, mitigation, and enhancement of Columbia River salmon and steelhead populations, is mandated by Congress through the Pacific Northwest Electric Power Planning and Conservation Act (Regional Act), Pub. L. 96-501. Section 4 (h) of the Regional Act directs the Northwest Power Planning Council to develop a Fish and Wildlife Program. BPA's Administrator is authorized in Section 4 (h) (10) (A) to ''use funds and the authorities available to the extent affected by the development and operation of any hydroelectric project of the Columbia River and its tributaries''. The fund is to be used to implement measures that are consistent with the Council's Fish and Wildlife Program. The research detailed in this final report is consistent with these objectives. This final report has been prepared as part of BPA's policy to encourage the preservation and dissemination of research results by publication in scientific journals.

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

    Science.gov (United States)

    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 (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

  19. Isolation and characterization of rhamnose-binding lectins from eggs of steelhead trout (Oncorhynchus mykiss) homologous to low density lipoprotein receptor superfamily.

    Science.gov (United States)

    Tateno, H; Saneyoshi, A; Ogawa, T; Muramoto, K; Kamiya, H; Saneyoshi, M

    1998-07-24

    Two L-rhamnose-binding lectins named STL1 and STL2 were isolated from eggs of steelhead trout (Oncorhynchus mykiss) by affinity chromatography and ion exchange chromatography. The apparent molecular masses of purified STL1 and STL2 were estimated to be 84 and 68 kDa, respectively, by gel filtration chromatography. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization time of flight mass spectrometry of these lectins revealed that STL1 was composed of noncovalently linked trimer of 31.4-kDa subunits, and STL2 was noncovalently linked trimer of 21.5-kDa subunits. The minimum concentrations of STL1, a major component, and STL2, a minor component, needed to agglutinate rabbit erythrocytes were 9 and 0.2 microg/ml, respectively. The most effective saccharide in the hemagglutination inhibition assay for both STL1 and STL2 was L-rhamnose. Saccharides possessing the same configuration of hydroxyl groups at C2 and C4 as that in L-rhamnose, such as L-arabinose and D-galactose, also inhibited. The amino acid sequence of STL2 was determined by analysis of peptides generated by digestion of the S-carboxamidomethylated protein with Achromobacter protease I or Staphylococcus aureus V8 protease. The STL2 subunit of 195 amino acid residues proved to have a unique polypeptide architecture; that is, it was composed of two tandemly repeated homologous domains (STL2-N and STL2-C) with 52% internal homology. These two domains showed a sequence homology to the subunit (105 amino acid residues) of D-galactoside-specific sea urchin (Anthocidaris crassispina) egg lectin (37% for STL2-N and 46% for STL2-C, respectively). The N terminus of the STL1 subunit was blocked with an acetyl group. However, a partial amino acid sequence of the subunit showed a sequence similarity to STL2. Moreover, STL2 also showed a sequence homology to the ligand binding domain of the vitellogenin receptor. We have also employed surface plasmon resonance biosensor

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  3. Idaho Habitat/Natural Production Monitoring Part I, 1995 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hall-Griswold, J.A.; Petrosky, C.E. (Idaho Department of Fish and Game, Boise, ID)

    1996-12-01

    The Idaho Department of Fish and Game (IDFG) has been monitoring trends in juvenile spring and summer chinook salmon, Oncorhynchus tshawytscha, and steelhead trout, O. mykiss, populations in the Salmon, Clearwater, and lower Snake River drainages for the past 12 years. This work is the result of a program to protect, mitigate, and enhance fish and wildlife affected by the development and operation of hydroelectric power plants on the Columbia River. Project 91-73, Idaho Natural Production Monitoring, consists of two subprojects: General Monitoring and Intensive Monitoring. This report updates and summarizes data through 1995 for the General Parr Monitoring (GPM) database to document status and trends of classes of wild and natural chinook salmon and steelhead trout populations. A total of 281 stream sections were sampled in 1995 to monitor trends in spring and summer chinook salmon Oncorhynchus tshawytscha and steelhead trout O. mykiss parr populations in Idaho. Percent carrying capacity and density estimates were summarized for 1985--1995 by different classes of fish: wild A-run steelhead trout, wild B-run steelhead trout, natural A-run steelhead trout, natural B-run steelhead trout, wild spring and summer chinook salmon, and natural spring and summer chinook salmon. The 1995 data were also summarized by subbasins as defined in Idaho Department of Fish and Game`s 1992--1996 Anadromous Fish Management Plan.

  4. Idaho habitat/natural production monitoring: Part 1. Annual report 1995

    International Nuclear Information System (INIS)

    Hall-Griswold, J.A.; Petrosky, C.E.

    1996-11-01

    The Idaho Department of Fish and Game (IDFG) has been monitoring trends in juvenile spring and summer chinook salmon, Oncorhynchus tshawytscha, and steelhead trout, O. mykiss, populations in the Salmon, Clearwater, and lower Snake River drainages for the past 12 years. This work is the result of a program to protect, mitigate, and enhance fish and wildlife affected by the development and operation of hydroelectric power plants on the Columbia River. Project 91-73, Idaho Natural Production Monitoring, consists of two subprojects: General Monitoring and Intensive Monitoring. This report updates and summarizes data through 1995 for the General Parr Monitoring (GPM) database to document status and trends of classes of wild and natural chinook salmon and steelhead trout populations. A total of 281 stream sections were sampled in 1995 to monitor trends in spring and summer chinook salmon Oncorhynchus tshawytscha and steelhead trout O. mykiss parr populations in Idaho. Percent carrying capacity and density estimates were summarized for 1985--1995 by different classes of fish: wild A-run steelhead trout, wild B-run steelhead trout, natural A-run steelhead trout, natural B-run steelhead trout, wild spring and summer chinook salmon, and natural spring and summer chinook salmon. The 1995 data were also summarized by subbasins as defined in Idaho Department of Fish and Game's 1992--1996 Anadromous Fish Management Plan

  5. Lyons Ferry Hatchery - Summer Steelhead, Final Report

    International Nuclear Information System (INIS)

    Watson, M.

    1996-05-01

    This report presents the findings of the independent audit of the Lyons Ferry Hatchery (Summer Steelhead). Lyons Ferry Hatchery is located downstream of the confluence of the Palouse and Snake rivers, about 7 miles west of Starbuck, Washington. The hatchery is used for adult collection of fall chinook and summer steelhead, egg incubation of fall chinook, spring chinook, steelhead, and rainbow trout and rearing of fall chinook, spring chinook, summer steelhead, and rainbow trout. The audit was conducted in April 1996 as part of a two-year effort that will include 67 hatcheries and satellite facilities located on the Columbia and Snake River system in Idaho, Oregon, and Washington. The hatchery operating agencies include the US Fish and Wildlife Service, Idaho Department of Fish and Game, Oregon Department of Fish and Wildlife, and Washington Department of Fish and Wildlife

  6. A Practical Approach to Rainbow Trout (Oncorhynchus mykiss) Seed Production

    OpenAIRE

    , Orhan Çakır

    2002-01-01

    Rainbow trout (Oncorhynchus mykiss) grows faster and has great disease resistance. Therefore this species has been preferred to culture for years. Fry production, feeding and management of broodstock are explained practically in order to increase profitability.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Wayne H.; Schricker, Jaym' e; Ruzychi, James R. (Oregon Department of Fish and Wildlife)

    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 evaluate 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 summer

  8. Influence of sex, migration distance, and latitude on life history expression in steelhead and rainbow trout (Oncorhynchus mykiss)

    Science.gov (United States)

    Ohms, Haley A.; Sloat, Matthew R.; Reeves, Gordon H.; Jordan, Chris E.; Dunham, Jason B.

    2014-01-01

    Abstract:In partially migratory species, such as Oncorhynchus mykiss, the emergence of life history phenotypes is often attributed to fitness trade-offs associated with growth and survival. Fitness trade-offs can be linked to reproductive tactics that vary between the sexes, as well as the influence of environmental conditions. We found that O. my kiss outmigrants are more likely to be female in nine populations throughout western North America (grand mean 65% female), in support of the hypothesis that anadromy is more likely to benefit females. This bias was not related to migration distance or freshwater productivity, as indicated by latitude. Within one O. my kiss population we also measured the resident sex ratio and did not observe a male bias, despite a high female bias among out migrants in that system. We provide a simulation to demonstrate the relationship between sex ratios and

  9. Imprinting Hatchery Reared Salmon and Steelhead Trout for Homing, Volume III of III; Disease and Physiology Supplements, 1978-1983 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Slatick, Emil; Gilbreath, Lyle G.; Harmon, Jerrel R. (Northwest and Alaska Fisheries Science Centr, Coastal Zone and Estuarine Studies Division, Seattle, WA)

    1988-02-03

    The main functions of the National Marine Fisheries Service (NMFS) Aquaculture Task biologists and contractual scientists involved in the 1978 homing studies were primarily a surveillance of fish physiology, disease, and relative survival during culture in marine net-pens, to determine if there were any unusual factors that might affect imprinting and homing behavior. The studies were conducted with little background knowledge of the implications of disease and physiology on imprinting and homing in salmonids. The health status of the stocks was quite variable as could be expected. The Dworshak and Wells Hatcheries steelhead suffered from some early stresses in seawater, probably osmoregulatory. The incidences of latent BKD in the Wells and Chelan Hatcheries steelhead and Kooskia Hatchery spring chinook salmon were extremely high, and how these will affect survival in the ocean is not known. Gill enzyme activity in the Dworshak and Chelan Hatcheries steelhead at release was low. Of the steelhead, survival in the Tucannon Hatchery stock will probably be the highest, with Dworshak Hatchery stock the lowest. This report contains five previously published papers.

  10. AFSC/ABL: 1996 Brood year Steelhead growth and early life-history transitions

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Heritabilities of growth, precocious maturation and smolting were measured in 75 families of juvenile steelhead or rainbow trout Oncorhynchus mykiss, progeny of...

  11. Study of Disease and Physiology in the 1979 Homing Study Hatchery Stocks: A Supplement to "Imprinting Salmon and Steelhead Trout for Homing", 1979 by Slatick, Gilbreath, and Walch.

    Energy Technology Data Exchange (ETDEWEB)

    Novotny, Anthony J.; Zaugg, Waldo S.

    1981-09-01

    The National Marine Fisheries Service (NMFS), under contract to the Bonneville Power Administration, is conducting research on imprinting salmon and steelhead for homing (Slatick et al. 1979, 1980; Novotny and Zaugg 1979). The studies were begun with little background knowledge of the effects of disease or certain physiological functions on imprinting and homing in salmonids. Consequently, work aimed at filling this void was begun by the authors in 1978 (Novotny and Zaugg 1979) and continued in 1979. In 1979, we examined random samples of normal populations of homing test fish at the hatcheries to determine the physiological readiness to migrate and adapt to seawater and general fish health. At the Manchester Marine Experimental Station, Manchester, Washington, we determined the survival of samples of the test fish maintained in marine net-pens after release from the hatcheries. Hatcheries and stocks sampled are listed in Table 1.

  12. Wild steelhead studies. 1993 Annual report

    International Nuclear Information System (INIS)

    Holubetz, T.B.

    1995-11-01

    Significant progress was attained in implementing the complex and challenging studies of wild steelhead Oncorhynchus mykiss production in Idaho. Study sites were selected and techniques were developed to collect the needed data in remote wilderness locations. Cursory examination of existing data provides indication that most wild steelhead stocks are under escaped, especially the Group B stocks. Abundance of wild steelhead is generally declining in recent years. The portable weir concept and electronic fish counting developed through this project have been well received by land owners and reviewing governmental agencies with less impact to the land, stream, and fishery resources than conventional permanent weirs

  13. Summer Steelhead Distribution [ds341

    Data.gov (United States)

    California Natural Resource Agency — Summer Steelhead Distribution October 2009 Version This dataset depicts observation-based stream-level geographic distribution of anadromous summer-run steelhead...

  14. Sex-specific vitellogenin production in immature rainbow trout

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, D.B.; Williams, D.E.

    1999-10-01

    Many xenobiotics interact with hormone systems of animals, potentially leading to a phenomenon commonly called endocrine disruption. Much attention has focused on steroid hormone systems and corresponding receptor proteins, particularly estrogens. Vitellogenin (Vg) was measured in sexually immature rainbow trout (Oncorhynchus mykiss) exposed to 17{beta}-estradiol (E{sub 2}) in the diet. Mixed-sex populations of trout aged 3, 6, 12, or 18 months were maintained separately and fed E{sub 2} at 0.05 or 2.5 mg/kg for 7d. Females fed E{sub 2} at 0.05 mg/kg consistently produced three- to fourfold greater amounts of Vg than similarly aged males. Age- and sex-matched fish fed E{sub 2} at 2.5 mg/kg produced equivalent amounts of Vg. Sex differences in Vg production were apparent only at a dose of E{sub 2} (0.05 mg/kg) that results in submaximal Vg induction. Their results document the importance of considering the sex of juvenile fish when using Vg production as a marker of xenoestrogen exposure.

  15. Biological and Physical Inventory of the Streams within the Nez Perce Reservation; Juvenile Steelhead Survey and Factors that Affect Abundance in Selected Streams in the Lower Clearwater River Basin, Idaho, 1983-1984 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Kucera, Paul A.; Johnson, David B. (Nez Perce Tribe, Lapwai, ID)

    1986-08-01

    A biological and physical inventory of selected tributaries in the lower Clearwater River basin was conducted to collect information for the development of alternatives and recommendations for the enhancement of the anadromous fish resources in streams on the Nez Perce Reservation. Five streams within the Reservation were selected for study: Bedrock and Cottonwood Creeks were investigated over a two year period (1983 to 1984) and Big Canyon, Jacks and Mission Creeks were studied for one year (1983). Biological information was collected and analyzed on the density, biomass, production and outmigration of juvenile summer steelhead trout. Physical habitat information was collected on available instream cover, stream discharge, stream velocity, water temperature, bottom substrate, embeddedness and stream width and depth. The report focuses on the relationships between physical stream habitat and juvenile steelhead trout abundance.

  16. Idaho Habitat/Natural Production Monitoring Part I, 1994 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hall-Griswold, Judy A.; Leitzinger, Eric J.; Petrosky, C.E. (Idaho Department of Fish and Game, Boise, ID

    1995-11-01

    A total of 333 stream sections were sampled in 1994 to monitor in chinook salmon and steelhead trout parr populations in Idaho. Percent carry capacity and density estimates were summarized by different classes of fish: wild A-run steelhead trout, wild B-run steelhead trout, natural A-run steelhead trout, natural B-run steelhead trout, wild spring and summer chinook salmon. These data were also summarized by cells and subbasins as defined in Idaho Department of Fish and Game`s 1992-1996 Anadromous Fish Management Plan.

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

    Energy Technology Data Exchange (ETDEWEB)

    Harnish, Ryan A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Green, Ethan D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Vernon, Christopher R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mcmichael, Geoffrey A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    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 hatchery 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 months after

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

    Science.gov (United States)

    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.

  19. Hood Canal Steelhead - Hood Canal Steelhead Supplementation Experiment

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Hood Canal Steelhead Project is a 17-year before-after-control-impact experiment that tests the effects of supplementation on natural steelhead populations in...

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

    Energy Technology Data Exchange (ETDEWEB)

    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 August 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 5,138 juvenile

  1. GROWTH, MORTALITY AND PRODUCTION OF BROWN AND RAINBOW TROUT IN NEW MEXICO STREAMS

    Directory of Open Access Journals (Sweden)

    S Leiner

    1995-06-01

    Full Text Available Thirty-two representative trout sites in 15 high elevation New Mexico streams (1,661 - 2560 m above sea level were sampled in 1988 and 1989. Fish was captured by consecutive removal via electrofishing in net-blocked segments from 65 to 160 m long. Maximum estimated trout length (Lm.ax was related inversely to yield (r2 = 0.351; p = 0.055. Instantaneous rate of mortality was also marginally related to yield (r2 = 0.294. The production index ranged from 1,38 to 32.02 g/m2/year. Variation in production was highly correlated to trout biomass (r2 = 0.910. Trout growth and production were best defined by the relationships where: cover, stream width, water temperature, yield by anglers, LMAX, and nitrate-nitrogen concentration were included.

  2. Effects of Temperature on Production and Specificity of Antibodies in Rainbow Trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Mikkelsen, Heidi; Nielsen, Michael Engelbrecht; Lindenstrom, Thomas

    2006-01-01

    The effect of temperature on production and affinity of antibodies against antigens from the parasitic ciliate Ichthyophthirius multifiliis were studied in rainbow trout (Oncorhynchus mykiss). Fish were immunized with I. multifiliis antigens and reared at three different temperatures, 5, 12, and 20...... reared at 5 C was similar to fish reared at 12 and 20 C. However, when samples were assayed at 12 and 20 C, the measured antibody response tended to be higher for the samples from trout reared at 12 and 20 C. Additionally, it was found that rainbow trout reared at 5 C showed a delayed but not hampered...

  3. Wild Steelhead Studies, Salmon and Clearwater Rivers, 1994 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Holubetz, Terry B; Leth, Brian D.

    1997-05-01

    To enumerate chinook salmon Oncorhynchus tshawytscha and steelhead O. mykiss adult escapements, weirs were operated in Marsh, Chamberlain, West Fork Chamberlain, and Running creeks. Beginning in late July 1994, a juvenile trap was installed in Running Creek to estimate juvenile outmigrants. Plans have been completed to install a weir in Rush Creek to enumerate steelhead adult escapement beginning in spring 1995. Design and agreements are being developed for Johnson Creek and Captain John Creek. Data collected in 1993 and 1994 indicate that spring chinook salmon and group-B steelhead populations and truly nearing extinction levels. For example, no adult salmon or steelhead were passed above the West Fork Chamberlain Creek weir in 1984, and only 6 steelhead and 16 chinook salmon were passed into the important spawning area on upper Marsh Creek. Group-A steelhead are considerably below desirable production levels, but in much better status than group-B stocks. Production of both group-A and group-B steelhead is being limited by low spawning escapements. Studies have not been initiated on wild summer chinook salmon stocks.

  4. Estimation of waste generated by the production of rainbow trout in Lake Tota, Colombia

    Directory of Open Access Journals (Sweden)

    Nixon Hernán Torres-Barrera

    2017-05-01

    Full Text Available In this study, the total waste from the production of rainbow trout, Oncorhynchus mykiss ( Wa l b a u m (Salmoniformes: Salmonidae in Lake Tota freshwater ecosystem, located in the Department of Boyacá, Colombia, and its potential impact on the lake was estimated. This economic activity has been carried out intensively since 2005 using submerged cages in the lake. With data obtained from the National Authority for Aquaculture and Fisheries (Aunap, the Autonomous Regional Corporation of Boyacá (Corpoboyacá, and the Chamber of Commerce of Sogamoso, fish farmers, their geographical location on the lake, production by these farms were identified, and with this information the amount of waste produced, including the amounts of nitrogen and phosphorus generated in this process was calculated. The results indicate that the lake is polluted due to intensive trout production. It is recommended to improve or modify trout production methods that will minimize water pollution.

  5. Escapement and Productivity of Spring Chinook Salmon and Summer Steelhead in the John Day River Basin, 2005-2006 Annual Technical Report.

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, Terra Lang; Wilson, Wayne H.; Ruzycki, James R. [Oregon Department of Fish and Wildlife

    2009-04-10

    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. 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, however, remain depressed relative to historic levels. Between the completion of the life history and natural escapement study in 1984 and the start of this project in 1998, spring Chinook spawning surveys did not provide adequate information to assess age structure, progeny-to-parent production values, smolt-to-adult survival (SAR), or natural spawning escapement. Further, only very limited information is available for steelhead life history, escapement, and productivity measures in the John Day subbasin. Numerous habitat protection and rehabilitation projects to improve salmonid freshwater production and survival have also been implemented in the basin and are in need of effectiveness monitoring. While our monitoring efforts outlined here will not specifically measure the effectiveness of any particular project, they will provide much needed background information for developing context for project-specific effectiveness monitoring efforts. To meet the data needs as index stocks, to assess the long-term effectiveness of habitat projects, and to differentiate freshwater and ocean survival, sufficient annual estimates of spawner escapement, age structure, SAR, egg-to-smolt survival, smolt-per-redd ratio, and freshwater habitat use are essential. We have begun to meet this need through spawning ground surveys initiated for spring Chinook salmon in 1998 and smolt PIT-tagging efforts initiated in 1999. Additional sampling and analyses to meet these goals

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

    Science.gov (United States)

    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...

  7. Steelhead Critical Habitat, Coast - NOAA [ds122

    Data.gov (United States)

    California Department of Resources — This layer depicts areas designated for Steelhead Critical Habitat as well as habitat type and quality in the Coastal California Steelhead ESUs (evolutionarily...

  8. Study of Disease and Physiology in the 1978 Homing Study Hatchery Stocks: A Supplement to "Imprinting Salmon and Steelhead Trout for Homing" by Slatick, Novotny, and Gilbreath, January 1979.

    Energy Technology Data Exchange (ETDEWEB)

    Novotny, Anthony J.; Zaugg, Waldo S.

    1979-11-01

    The main functions of the National Marine Fisheries Service (NMFS) Aquaculture Task biologists and contractual scientists involved in the 1978 homing studies were primarily a surveillance of fish physiology, disease, and relative survival during culture in marine net-pens, to determine if there were any unusual factors that might effect imprinting and homing behavior. The studies were conducted with little background knowledge of the implications of disease and physiology on imprinting and homing in salmonids. Hatcheries and stocks sampled are listed in Table 1. The health status of the stocks was quite variable as could be expected. The Dworshak and Wells Hatcheries steelhead suffered from some early stresses in seawater, probably osmoregulatory. The incidences of latent BKD in the Wells and Chelan Hatcheries steelhead and Kooskia Hatchery spring chinook salmon were extremely high, and how these will effect survival in the ocean is not known. Gill enzyme activity in the Dworshak and Chelan Hatcheries steelhead at release was low. Of the steelhead, survival in the Tucannon Hatchery stock will probably be the highest, with Dworshak Hatchery stock the lowest. The analyses conducted by the veterinary pathologist indicate that overall there was no evidence of serious pathological conditions that might be disastrous to any given stock, but at this time it is also difficult to interpret the results of certain types of clinical pathology that have either not been previously reported or extensively studied. For example, if the 77% incidence of basophillic granular organisms in the gills of the Carson coho salmon does represent an infestation of microsporidian protozoan parasites, is the intensity of infestation severe enough to cause irreparable damage that might affect survival? The results of the viral assays are questionable because the Rangen Laboratory is the only one that found evidence of viruses in these stocks (however, the veterinary pathologist did find evidence

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

    Science.gov (United States)

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

    2018-01-01

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

  10. Productive characteristics of age-3 brood brown trout (Salmo trutta reared in the conditions industrial aquaculture

    Directory of Open Access Journals (Sweden)

    L. Haloyan

    2017-03-01

    Full Text Available Purpose. Study and analysis of productive and reproductive parameters of brood brown trout reared in the conditions of industrial aquaculture with the use of feeding with specialized artificial feeds. Methodology. Fish rearing was performed using a technology traditional for rainbow trout. Biological evaluation of fish was performed on live material according to the scheme developed by I.F. Pravdin (1966 for salmonids. Fish were anesthetized with “Propiscin”. Metric parameters were measured with the aid of a ruler and caliper. Fish weight was determined on electronic balances. Eggs were preserved in a 4% formalin solution, weight of individual eggs was determined with the aid of torsion balances, egg diameter with a caliper. The duration of spermatozoid motility in males was determined under a microscope under 10X40 magnification with the aid of a stopwatch, sperm concentration was determined in a Goriaev chamber. Multiple regression analysis was performed in JMP IN 4 (SAS Institute. The factor was considered significant if р <0.05. Findings. Brood brown trout reared on specialized artificial feeds had following productive parameters: mean body weight of age-3 fish was 458 g in males and 453 g in females. Mean working fecundity of age-3 fish as 1847 eggs, mean relative working fecundity was 3971 eggs, the mean qualitative parameters of which were: weight of 61.5 g, diameter of 74.7 mm. The reproductive characteristics of age-3 males was high – mean fecundity was 1391 million sperm cells, their motility was 35 sec. Originality. For the first time we reared a stock of brood brown trout in industrial conditions with the use of feeding with specialized artificial feeds. Practical value. The obtained results are a component of the development of a complex technology of salmonid fish rearing with an objective to broad the assortment of valuable gourmet products and to justify the measures on artificial reproduction of brown trout in rivers of

  11. Methow River Steelhead - Methow River Steelhead hatchery reform research

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Steelhead in Pacific Northwest hatcheries are typically reared for release as 1-year-old smolts, rather than the 2and 3-year-old smolt life history patterns found in...

  12. John Day Steelhead - Genetic Monitoring of John Day Steelhead

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Assist Oregon Department of Fish and Wildlife (ODFW) in determining the extent to which genetic introgression exists between Snake River hatchery steelhead straying...

  13. Oxidative stability during storage of fish oil from filleting by-products of rainbow trout (Oncorhynchus mykiss) is largely independent of the processing and production temperature

    DEFF Research Database (Denmark)

    Honold, Philipp; Nouard, Marie-Louise; Jacobsen, Charlotte

    2016-01-01

    Rainbow trout (Oncorhynchus mykiss) is the main fish species produced in Danish fresh water farming. Large amounts of fileting by-products like heads, bones, tails (HBT), and intestines are produced when rainbow trout is processed to smoked rainbow trout filets. The filleting by-products can...... be used to produce high quality fish oil. In this study, the oxidative stability of fish oil produced from filleting by-products was evaluated. The oil was produced from conventional or organic fish (low and high omega-3 fatty acid content) at different temperatures (70 and 90°C). The oxidative stability...

  14. Steelhead Spawning Surveys Near Locke Island, Hanford Reach of the Columbia River; TOPICAL

    International Nuclear Information System (INIS)

    DR Geist; RP Mueller

    1999-01-01

    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, 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

  15. Fish production and some traits of meat quality in rainbow trout (Oncorhynchus mykiss farmed in different production systems

    Directory of Open Access Journals (Sweden)

    St. Stoyanova

    2016-12-01

    Full Text Available Abstract. The rainbow trout (Oncorhynchus mykiss, an important species in Bulgarian aquaculture, is farmed in different production systems as raceways, net cages etc. The aim of the present study was to evaluate the effect of two different rearing systems on fish production, survival rate, meat chemical, mineral composition and farming economic efficiency of culticated rainbow trout (Oncorhynchus mykiss. The information from a survey on fish production and economic efficiency traits was collected from two national rainbow trout farms using the two commonest fish farming systems: in raceways, Happy Fish Ltd fish farm and in net cages, Forest Group Ltd fish farm. The average individual weight gain (g, total weight gain (kg, feed conversion ratio, production costs of 1 kg fish and the economic efficiency coefficients were determined for the two studied fish farms. The final live weight of rainbow trout in net cages was 0.30 kg vs 0.35 kg in raceways. The average individual weight gain was higher in raceways farming system (0.30 kg than in net cages farm (0.26 kg. The mortality rate of fish in raceways was considerably lower: only 1% as compared to that in net cages (4%. The feed conversion ratio at the end of the experiment showed identical values for trout in both farms 1.01. The meat water content of fish reared in raceways and net cages was 77.46±0.65% and 74.52±0.52% respectively (P≤0.01.The protein content of fish meat was higher in fish farmed in net cages 18.84±0.29% as compared to fish cultivated in raceways 17.60±0.49% (P 0.05. Meat fat content of rainbow trout, reared in the net cage system was also considerably higher (5.26±0.30% than the respective parameter in fish farmed in ponds (3.60±0.15% (P≤0.001. The content of Ca and P was higher in rainbow trouts reared in raceways (138.96±1.12 mg.kg and 2844.32±39.31 mg.kg 1 -1 -1 compared with the values of these parameters of fish in net cages (134.46±1.96 mg.kg and 2690.31±42

  16. Gills as morphological biomarkers in extensive and intensive rainbow trout (Oncorhynchus mykiss, Walbaum 1792) production technologies.

    Science.gov (United States)

    Strzyżewska-Worotyńska, Emilia; Szarek, Józef; Babińska, Izabella; Gulda, Dominika

    2017-11-06

    We investigated environmental impacts on rainbow trout (Oncorhynchus mykiss) reared at fish farms with either extensive technology, in a flow-through system (FTS, n = 3), or intensive technology, in a recirculating aquaculture system (RAS, n = 3). All fish were fed the same rations. Fish were caught in spring and autumn (body mass, 501-750 g) from these six farms. We performed macroscopic (intact fish) and microscopic (gills stained with haematoxylin/eosin) examinations. Lesions were categorised based on the type and location of structural abnormalities. The histopathological index (HAI) was calculated, and each lesion was scored. Fish reared in FTS or RAS were compared for the prevalence of morphological lesions. Gill epithelial hypertrophy and hyperplasia comprised 73% (RAS) to 79% (FTS) of all morphological abnormalities. In spring and autumn, lesions comprised, respectively, 11 and 18% (FTS) and 16 and 10% (RAS) mucous and chloride cell abnormalities and 8 and 4% (FTS) and 10 and 3% (RAS) blood vessel abnormalities. Diffuse, irreversible gill lesions were observed sporadically in all fish. Gill epithelium received the most exposure to environmental pathogens. HAIs indicated that normal gill architecture and minor lesions predominated in all fish. However, among trout caught in spring, moderate and extensive changes in gills occurred more commonly with RAS (34%) than with FTS (17%). Trout caught in autumn displayed no great differences. These results indicated that FTS prepared fish better than RAS for wintering. Moreover, we showed that gills were an excellent biomarker for analysing the impact of extensive and intensive production environments on rainbow trout.

  17. Natural Production Monitoring and Evaluation; Idaho Department of Fish and Game, 2003-2004 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, Timothy; Johnson, June; Bunn, Paul (Idaho Department of Fish and Game, Boise, ID)

    2004-12-01

    This report covers the following 3 parts of the Project: Part 1--Monitoring age composition of wild adult spring and summer Chinook salmon returning to the Snake River basin in 2003 to predict smolt-to-adult return rates Part 2--Development of a stock-recruitment relationship for Snake River spring/summer Chinook salmon to forecast natural smolt production Part 3--Improve the precision of smolt-to-adult survival rate estimates for wild steelhead trout by PIT tagging additional juveniles.

  18. Variation in Sensory Profile of Individual Rainbow Trout (Oncorhynchus mykiss) from the Same Production Batch

    DEFF Research Database (Denmark)

    Green-Petersen, Ditte; Hyldig, Grethe

    2010-01-01

    The variation in sensory profile of rainbow trout (Oncorhynchus mykiss), belonging to the same aquaculture production batch and handled the same way, was explored by using objective sensory profiling on heat-treated minced fillets. In addition, quality index, mechanical texture, pH, fat, and water...... content were measured. Different groups of fish were sampled 3 different times during a production day. The results showed significant differences in the sensory profiles of individual fish within all 3 groups as well as significant differences between the groups. Differences in mechanical texture were...... not explain the differences in the sensory profiling or in the mechanical texture measurements. The results showed that significant differences in the sensory profiles of individual fish from the same aquaculture production batch may occur. Furthermore, the results also showed sensory differences between...

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

    Science.gov (United States)

    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...

  20. Quantifying the net benefit impacts of the Troy Waste Water Treatment Plant on Steelhead Habitat in the West Fork Little Bear Creek drainage

    Science.gov (United States)

    Sanchez-Murillo, R.; Brooks, E. S.; Boll, J.

    2010-12-01

    Discharge of waste water treatment plants (WWTPs) typically is viewed to result in water quality impairment. However, WWTPs can also be a source of nutrients to enhance the salmonid food web as well as an efficient way to maintain acceptable water temperature regimes and flow conditions during summer. We observed this paradox in West Fork Little Bear Creek (WFLB) in the City of Troy, Idaho. Despite the nutrient load, the WFLB had the highest Steelhead trout density in the watershed, with a mean density of 13.2 fish/100 m2. The objective of this project was to utilize a water quality model, QUAL2kw, and an ecology assessment to examine how the nutrient load from the WWTP affects: a) habitat conditions for steelhead juveniles, and b) physic-chemical parameters. Four monitoring stations were installed from May through November in 2009 and 2010. An undisturbed creek was used as a control site in 2010. Dissolved oxygen (DO), electrical conductivity, temperature, and discharge were measured continuously at each monitoring station. Weekly samples were collected at each monitoring station and analyzed for nitrate, nitrite, ammonia, total Kjeldahl nitrogen, total phosphorous, and orthophosphates. In 2010, Chlorophyll a was analyzed weekly, while bottom algae biomass was determined monthly. Results show that during summer months, the WWTP provides the majority of the flow (0.1 cfs) in the creek. Water samples and DO measurements taken 200 m downstream of the plant during late summer months indicate that nitrification process leads to low DO level well below the state standard of 6 mg/L for cold water biota. However dissolved oxygen levels recover within 1 km downstream. Discharge data suggest that without the flow from the treatment most of the creek would dry during late summer months. Abundance of macroinverbrates, high primary productivity, and sustained flow during summer suggests that the effluent from the WWTP is a net benefit to the Steelhead habitat in the basin

  1. Variation in sensory profile between individual Rainbow trout from the same production batch

    DEFF Research Database (Denmark)

    Hyldig, Grethe; Green-Petersen, Ditte

    The variation in sensory properties between individual Rainbow trout (Oncorhynchus mykiss) belonging to the same aquaculture production batch was explored by using objective sensory profiling on minced and heat treated fillets. Additionally, Quality Index, mechanical texture, pH, fat and water...... content were measured. 30 fish, all from the same production batch, were sampled at three different times making three groups (ten fish each time). The results showed differences in the sensory profile between individual fish within all three groups. Also sensory differences between the three groups...... of fish were found. Similar differences in mechanical texture were found between individuals in two of the three groups and between the groups. No differences were found in Quality Index neither between individuals nor groups. A significant correlation between lipid content and firm texture was observed...

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

    Science.gov (United States)

    Lowery, Erin D.; Beauchamp, David A.

    2015-01-01

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

  3. Development of healthy marine ingredients from waste products from smoked rainbow trout

    DEFF Research Database (Denmark)

    Jacobsen, Charlotte; Honold, Philipp; Nouard, Marie-Louise

    2014-01-01

    There is an increasing demand for healthy marine omega-3 oils as well as new functional proteins for human consumption. At the same time there is an increasing demand for fish oil as an ingredient in fish feed due to the growth in production of farmed fish. The aquaculture industry currently uses...... approx. 850.000 tons of fish oil per year, which is expected to increase significantly in the coming years. The demand for fish oil for human consumption has been estimated to 425.000 tons by 2017. The present production of fish oil from wild fish is 1 mio. tons/year. Due to sustainability issues...... it is not possible to increase the production of fish oil from wild fish further. A possible source of omega-3 oils for human consumption is waste products from the fish industry. At present only approximately 40 % of the fish is used for human consumption and the rest is turned into waste products. Rainbow trout...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    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 and two are in preparations.

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

    Energy Technology Data Exchange (ETDEWEB)

    Blouin, Michael

    2003-05-01

    microsatellite-based pedigree analysis, the relative total reproductive success (adult-to-adult production) of hatchery (H{sub old} or H{sub new}) and wild (W) fish for two populations, over multiple brood years. Our analyses of samples from fish that bred in the early to mid 1990's show that fish of 'old' hatchery stocks have much lower total fitness than wild fish (17% to 54% of wild fitness), but that 'new' stocks have fitness that is similar to that of wild fish (ranging from 85% to 108% of wild fitness, depending on parental gender and run year). Therefore, our results show that the decision to phase out the old, out-of-basin stocks and replace them with new, conservation hatchery stocks was well founded. We also conclude that the H{sub new} fish are leaving behind substantial numbers of wild-born offspring. The similar fitnesses of H{sub new} and W fish suggests that wild-born offspring of H{sub new} fish are unlikely to have negative genetic effects on the population when they in turn spawn in the wild. We will test this hypothesis once enough F2 offspring have returned. Another interesting result is that we were unable to match a large fraction of the unclipped, returning fish with parents from their brood year. Furthermore, we were missing more fathers than mothers. Because we sampled almost every possible anadromous parent, these results suggest that nonanadromous trout or precocious parr may be obtaining a substantial number of matings. Substantial reproduction by precocious parr could be one unintended consequence of the hatchery program.

  6. Aspects Regarding the Influence of Growth Technology Concerning the Performances Production of the Rainbow Trout (Oncorhynchus Mykiss

    Directory of Open Access Journals (Sweden)

    Daniel Cocan

    2012-10-01

    Full Text Available Experiments were conducted throughout 2009 and 2010. At the beginning of experiments, both in 2009 and in 2010, were formed two groups (M-control group; E-experimental group, each group far 600 rainbow trout (Oncorhynchus mykiss. Control group M has been exploited in the Fiad trout farm, Bistriţa-Năsăud County, and the experimental group E was operated in a recirculating system arranged in Cluj-Napoca. Experiments were conducted over 210 days, both in 2009 and in 2010. Initial body weight of the specimens was 22.70±0.40 g – group M, and 22.68±0.39 – group E, in 2009. In the second experimental series (2010, the initial body weight of the rainbow trout specimens was 22.69±0.28 g – group M, respectively 22.56±0.31 g – group E. As factors which influencing directly the growth dynamic of rainbow trout, were monitored the physico-chemical parameters of water from the two locations, and feed consumption. Production performances of the trout from the two experimental groups, were assessed using as indicators total weight gain (TWG and specific growth rate (SGR. In 2009, TWG=370.92±4.37 g – group E vs. 79.59±1.09 g – group M (p<0.001, and SGR=1.55±0.01 g/day – group E vs. 0.33±0.005 g/day – group M (p<0.001. In 2010, TWG=377.85±3.97 g – group E vs. 103.78±1.28 g – group M (p<0.001, and SGR=1.57±0.01 g/day – group E vs. 0.43±0.005 g/day – group M. Analyzing the two indicators (TWG and SGR, we can conclude that due to optimal environmental conditions provided by the recirculating system, the production performances of rainbow trout in both experimental series, were significantly higher in group E compared with group M.

  7. AN EVALUATION OF WATER QALITY OF AKPINAR STREAM (DENİZLİ WHERE TROUT PRODUCTION TAKES PLACE

    Directory of Open Access Journals (Sweden)

    Esengül KÖSE

    2012-08-01

    Full Text Available In this study, 20 physicochemical parameters were measured mountly in 2007 and seasonaly in 2008 and 2009 on Akpınar Stream, which is located within the borders of Denizli and has 13 trout production facility. The data obtained were evaluated according to the fresh water fish directive which was agreed by the Commision of European Union (EC Directives and Water Pollution Control Regulation Criteria. We determined that, the measured parameters on the first station do not constitute any risk for Salmonids and Cyprinids according to EC Directives and in the second station, the valuesof biological oxygen demand and nitrite were high enough to adversely affect the health of fish. There is not a significant difference between two stations for the parameters of oxygen, nitrate, totalnitrogen, pH, chemical oxygen demand, acid binding capacity, total hardness and chlorine. The parametes of total suspended solids, ammonium, nitrite, secondary phosphate, total phosphorus, organicmatter, ammonia, biological oxygen demand, turbidity, temperature and flow rate were significantly high in second station (p<0.05. The reason of high levels of the parameters especially origin of organic pollution in the secod station is fish feces and feed wastes which directly given into the water. Settling ponds should be used properly and controls should be provided to increase for more healtyproduction.

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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

  10. Functional characterization of estrogen receptor subtypes, ERα and ERβ, mediating vitellogenin production in the liver of rainbow trout

    International Nuclear Information System (INIS)

    Leanos-Castaneda, Olga; Kraak, Glen van der

    2007-01-01

    The estrogen-dependent process of vitellogenesis is a key function on oviparous fish reproduction and it has been widely used as an indicator of xenoestrogen exposure. The two estrogen receptor (ER) subtypes, ERα and ERβ, are often co-expressed in the liver of fish. The relative contribution of each ER subtype to modulate vitellogenin production by hepatocytes was studied using selected compounds known to preferentially interact with specific ER subtypes: propyl-pyrazole-triol (PPT) an ERα selective agonist, methyl-piperidino-pyrazole (MPP) an ERα selective antagonist, and diarylpropionitrile (DPN) an ERβ selective agonist. First, the relative binding affinity of the test compounds to estradiol for rainbow trout hepatic nuclear ER was determined using a competitive ligand binding assay. All the test ligands achieved complete displacement of specific [ 3 H]-estradiol binding from the nuclear ER extract. This indicates that the test ligands have the potential to modify the ER function in the rainbow trout liver. Secondly, the ability of the test compounds to induce or inhibit vitellogenin production by primary cultures of rainbow trout hepatocytes was studied. Estradiol and DPN were the only compounds that induced a dose-dependent increase on vitellogenin synthesis. The lack of vitellogenin induction by PPT indicates that ERα could not have a role on this reproductive process whereas the ability of DPN to induce vitellogenin production supports the participation of ERβ. In addition, this hypothesis is reinforced by the results obtained from MPP plus estradiol. On one hand, the absence of suppressive activity of MPP in the estradiol-induced vitellogenin production does not support the participation of ERα. On the other hand, once blocked ERα with MPP, the only manifestation of agonist activity of estradiol would be achieved via ERβ. In conclusion, the present results indicate that vitellogenin production is mainly mediated through ERβ, implying, furthermore

  11. Puget Sound steelhead life cycle model analyses - Population Viability Analysis

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This research was initiated by the Puget Sound Steelhead Technical Recovery Team to develop viability criteria for threatened Puget Sound steelhead and to support...

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

    Energy Technology Data Exchange (ETDEWEB)

    Branstetter, Ryan; Whiteaker, John; Hatch, Douglas R. (Columbia River Inter-Tribal Fish Commission, Portland, OR)

    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 reestablish 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 (first 2

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

    Energy Technology Data Exchange (ETDEWEB)

    Branstetter, Ryan; Whiteaker, John; Hatch, Douglas R. (Columbia River Inter-Tribal Fish Commission, Portland, OR)

    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 reestablish 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 (first 2

  14. Iteroparity in Columbia River summer-run steelhead (Oncorhynchus mykiss) : implications for conservation

    International Nuclear Information System (INIS)

    Keefer, M.L.; Boggs, C.T.; Peery, C.A.; Evans, A.F.

    2008-01-01

    This study examined the outmigration environment for steelhead kelts (anadromous rainbow trout, Oncorhynchus mykiss) in the Columbia River Basin, where summer-run kelts must pass up to 9 hydroelectric dams and reservoirs to reach the Pacific Ocean. Such fish passage barriers present many direct and indirect mortality hazards for outmigrating kelts. In some years, kelt migration mortality in the impounded portion of the system can be higher than 95 per cent. Current efforts to improve kelt survival in the Columbia system include increasing iteroparity to take advantage of genetic and demographic benefits of repeat spawners. Some of the basic iteroparity information gaps in the aggregated summer-run steelhead population of the interior Columbia River Basin were addressed in this study. Kelt demographics were collected along the outmigration corridor. Repeat spawner return rates were examined along with kelt demographics, outmigration timing and collection location and year. The roles of these factors in predicting repeat spawner returns were evaluated using an information-theoretic approach. The life history characteristics of returning fish was examined with reference to breeding interval, migration timing and distribution within the Columbia River Basin. The study tested whether repeat spawner return rates would be affected by outmigration distance and whether they would differ among demographic groups. It was concluded that the expression of iteroparity among interior Columbia River steelhead has persisted despite decades of impoundment-related selection pressures. Post spawn kelts and repeat spawners in downstream fish bypass systems at the Columbia River and Snake River dams were found to be disproportionately female and of wild origin. The results of this study provide baseline data for evaluating kelt mortality mitigation efforts and basic life history information for steelhead conservation planning. 78 refs., 4 tabs., 4 figs

  15. The production of fluorescent transgenic trout to study in vitro myogenic cell differentiation

    Directory of Open Access Journals (Sweden)

    Rescan Pierre-Yves

    2010-05-01

    Full Text Available Abstract Background Fish skeletal muscle growth involves the activation of a resident myogenic stem cell population, referred to as satellite cells, that can fuse with pre-existing muscle fibers or among themselves to generate a new fiber. In order to monitor the regulation of myogenic cell differentiation and fusion by various extrinsic factors, we generated transgenic trout (Oncorhynchus mykiss carrying a construct containing the green fluorescent protein reporter gene driven by a fast myosin light chain 2 (MlC2f promoter, and cultivated genetically modified myogenic cells derived from these fish. Results In transgenic trout, green fluorescence appeared in fast muscle fibers as early as the somitogenesis stage and persisted throughout life. Using an in vitro myogenesis system we observed that satellite cells isolated from the myotomal muscle of transgenic trout expressed GFP about 5 days post-plating as they started to fuse. GFP fluorescence persisted subsequently in myosatellite cell-derived myotubes. Using this in vitro myogenesis system, we showed that the rate of muscle cell differentiation was strongly dependent on temperature, one of the most important environmental factors in the muscle growth of poikilotherms. Conclusions We produced MLC2f-gfp transgenic trout that exhibited fluorescence in their fast muscle fibers. The culture of muscle cells extracted from these trout enabled the real-time monitoring of myogenic differentiation. This in vitro myogenesis system could have numerous applications in fish physiology to evaluate the myogenic activity of circulating growth factors, to test interfering RNA and to assess the myogenic potential of fish mesenchymal stem cells. In ecotoxicology, this system could be useful to assess the impact of environmental factors and marine pollutants on fish muscle growth.

  16. Establishing a benchmarking for fish farming - profitability, productivity and energy efficiency of German, Danish and Turkish rainbow trout grow-out systems

    DEFF Research Database (Denmark)

    Lasner, Tobias; Brinker, Alexander; Nielsen, Rasmus

    2017-01-01

    The promotion of Blue Growth in aquaculture requires an understanding of the economic drivers influencing the sector at farm level, but the collection of reliable and comparable data at this level is time-consuming and expensive. This study suggests an alternative strategy for qualitative sampling...... of freshwater trout farms in Germany, Denmark and Turkey, using a combination of existing data, group discussions and interviews with trout farmers, consultants and researchers. Nine 'typical' trout farming models are described, focusing on profitability, productivity and energy efficiency and allowing in......-depth comparative economic analyses of different production systems at farm level, across regions. Our results show that the majority of the farms investigated have been profitable. Turkish farms benefit from competitive advantages due to low wages, low capital investment and favourable climate conditions. Large...

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

    Energy Technology Data Exchange (ETDEWEB)

    Hatch, Douglas R.; Branstetter, Ryan (Columbia River Inter-Tribal Fish Commission, Portland, OR); Blodgett, Joe (Yakama Nation, Toppenish, WA)

    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) 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

  18. Salmon and steelhead genetics and genomics - Epigenetic and genomic variation in salmon and steelhead

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Conduct analyses of epigenetic and genomic variation in Chinook salmon and steelhead to determine influence on phenotypic expression of life history traits. Genetic,...

  19. Salish Sea Marine Survival (Steelhead) - Early Marine Survival of Puget Sound Steelhead

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The primary objectives of this study are to estimate a predation rate by harbor seals on steelhead smolt in Puget Sound, and determine whether predation by harbor...

  20. Steelhead migration - Tracking steelhead migration from the Columbia River through the Pacific Ocean

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tag juvenile Columbia River steelhead in the Columbia estuary with acoustic tags to determine their marine distributions. This was a small pilot project to test our...

  1. Historical Population Structure of Central Valley Steelhead and Its Alteration by Dams

    Directory of Open Access Journals (Sweden)

    Steven T. Lindley

    2006-02-01

    Full Text Available Effective conservation and recovery planning for Central Valley steelhead requires an understanding of historical population structure. We describe the historical structure of the Central Valley steelhead evolutionarily significant unit using a multi-phase modeling approach. In the first phase, we identify stream reaches possibly suitable for steelhead spawning and rearing using a habitat model based on environmental envelopes (stream discharge, gradient, and temperature that takes a digital elevation model and climate data as inputs. We identified 151 patches of potentially suitable habitat with more than 10 km of stream habitat, with a total of 25,500 km of suitable habitat. We then measured the distances among habitat patches, and clustered together patches within 35 km of each other into 81 distinct habitat patches. Groups of fish using these 81 patches are hypothesized to be (or to have been independent populations for recovery planning purposes. Consideration of climate and elevation differences among the 81 habitat areas suggests that there are at least four major subdivisions within the Central Valley steelhead ESU that correspond to geographic regions defined by the Sacramento River basin, Suisun Bay area tributaries, San Joaquin tributaries draining the Sierra Nevada, and lower-elevation streams draining to the Buena Vista and Tulare basins, upstream of the San Joaquin River. Of these, it appears that the Sacramento River basin was the main source of steelhead production. Presently, impassable dams block access to 80% of historically available habitat, and block access to all historical spawning habitat for about 38% of the historical populations of steelhead.

  2. Effects of excretory/secretory products from Anisakis simplex (Nematoda) on immune gene expression in rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Bahlool, Qusay Zuhair Mohammad; Skovgaard, Alf; Kania, Per Walter

    2013-01-01

    Excretory/secretory (ES) products are molecules produced by parasitic nematodes, including larval Anisakis simplex, a parasite occurring in numerous marine fish hosts. The effects of these substances on host physiology have not been fully described. The present work elucidates the influence of ES...... substances on the fish immune system by measuring immune gene expression in spleen and liver of rainbow trout (Oncorhynchus mykiss) injected intraperitoneally with ES products isolated from A. simplex third stage larvae. The overall gene expression profile of exposed fish showed a generalized down....... This type of hydrolytic enzyme activity may play a role in nematode penetration of host tissue. In addition, based on the notion that A. simplex ES products may have an immune-depressive effect (by minimizing immune gene expression) it could also be suggested that worm enzymes directly target host immune...

  3. Global gene expression in muscle from fasted/refed trout reveals up-regulation of genes promoting myofibre hypertrophy but not myofibre production.

    Science.gov (United States)

    Rescan, Pierre-Yves; Le Cam, Aurelie; Rallière, Cécile; Montfort, Jérôme

    2017-06-07

    Compensatory growth is a phase of rapid growth, greater than the growth rate of control animals, that occurs after a period of growth-stunting conditions. Fish show a capacity for compensatory growth after alleviation of dietary restriction, but the underlying cellular mechanisms are unknown. To learn more about the contribution of genes regulating hypertrophy (an increase in muscle fibre size) and hyperplasia (the generation of new muscle fibres) in the compensatory muscle growth response in fish, we used high-density microarray analysis to investigate the global gene expression in muscle of trout during a fasting-refeeding schedule and in muscle of control-fed trout displaying normal growth. The compensatory muscle growth signature, as defined by genes up-regulated in muscles of refed trout compared with control-fed trout, showed enrichment in functional categories related to protein biosynthesis and maturation, such as RNA processing, ribonucleoprotein complex biogenesis, ribosome biogenesis, translation and protein folding. This signature was also enriched in chromatin-remodelling factors of the protein arginine N-methyl transferase family. Unexpectedly, functional categories related to cell division and DNA replication were not inferred from the molecular signature of compensatory muscle growth, and this signature contained virtually none of the genes previously reported to be up-regulated in hyperplastic growth zones of the late trout embryo myotome and to potentially be involved in production of new myofibres, notably genes encoding myogenic regulatory factors, transmembrane receptors essential for myoblast fusion or myofibrillar proteins predominant in nascent myofibres. Genes promoting myofibre growth, but not myofibre formation, were up-regulated in muscles of refed trout compared with continually fed trout. This suggests that a compensatory muscle growth response, resulting from the stimulation of hypertrophy but not the stimulation of hyperplasia

  4. Effects of sex steroids, sex, and sexual maturity on cortisol production: an in vitro comparison of chinook salmon and rainbow trout interrenals.

    Science.gov (United States)

    McQuillan, H James; Lokman, P Mark; Young, Graham

    2003-08-01

    Sex steroids appear to be responsible for hyperactivation of the hypothalamus-pituitary-interrenal (HPI) axis that occurs in mature semelparous Pacific salmon as a prelude to post-spawning (programmed) death. This study was undertaken to examine the direct effects of sex steroids on interrenal activity of semelparous (chinook salmon) and iteroparous (rainbow trout) salmonids using an in vitro incubation system. In addition, phenotypic sex differences in cortisol production by interrenals of sexually mature (spawning) rainbow trout and chinook salmon were investigated. Interrenal tissue from juvenile and sexually mature chinook salmon and rainbow trout was incubated for 48 h in culture medium containing either no steroid (controls), 1 microM estradiol (E2) or 1 microM 11-ketotestosterone (11-KT). This tissue was then challenged for 3h with either pregnenolone, dibutyryladenosine 3('):5(')-cyclic monophosphate (dbcAMP) or forskolin, or synthetic human adrenocorticotropic hormone (ACTH(1-24)). Sex differences in in vitro interrenal cortisol production were assessed using separate tissue pools challenged with the same agents. Cortisol in media was measured by radioimmunoassay. E2 suppressed the ability of juvenile chinook salmon interrenals to utilize pregnenolone as substrate for cortisol synthesis. In mature female chinook salmon the suppressive effect of E2 was less pronounced, but was observed as a reduced response of interrenals to both pregnenolone and dbcAMP. E2 did not affect ACTH(1-24) stimulated cortisol production. Immature and mature rainbow trout interrenals were both relatively insensitive to E2. 11-KT did not affect cortisol production by juvenile chinook salmon and juvenile or mature rainbow trout, and had only minor effects in male and female spawning chinook salmon. In mature chinook salmon and rainbow trout, the interrenals of females were more responsive to ACTH stimulation and showed a greater utilization of pregnenolone as a substrate than

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

    Energy Technology Data Exchange (ETDEWEB)

    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 steelhead 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 the

  6. Juvenile competitive bottleneck in the production of brown trout in hydroelectric reservoirs due to intraspecific habitat segregation

    International Nuclear Information System (INIS)

    Hegge, O.; Hesthagen, T.; Skurdal, J.

    1993-01-01

    Resource utilization and growth of brown trout were studied in four deep (mean depths 16.2 - 37.5 m) Norwegian hydroelectric reservoirs by benthic and pelagic gillnet sampling. In all the reservoirs supplementary stockings are carried out. The brown trout were spatially segregated according to size as the habitat use of small individuals (< 180-220 mm) was completely restricted to benthic habitats, whereas larger individuals mainly utilized the upper strata of pelagic waters. It is argued that the pelagic habitat is the more rewarding, and that small-sized brown trout are forced into the less favourable benthic habitat through social interactions with larger specimens. This is supported by an increase in growth of brown trout from their third to fifth year of life, which seems to be related to the shift from benthic to pelagic behaviour. It is also argued that the conditions for small-sized brown trout may be a bottleneck in the capacity to produce brown trout in hydroelectric reservoirs with limited benthic feeding conditions, despite ample access to food in pelagic habitats. When evaluating the possibility of increasing the yield of brown trout through supplementary stockings, it is therefore important to consider food and growth conditions for all age and size groups of brown trout. In reservoirs with poor benthic feeding conditions it may be necessary to stock with brown trout of sizes that are large enough to utilize pelagic habitat, to avoid the limiting benthic living stage. (Author)

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

    Energy Technology Data Exchange (ETDEWEB)

    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 common 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.

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

    Science.gov (United States)

    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

  9. Microbiological changes occurring in trout fillets (Oncorhynchus mykiss W. 1792) salted and treated with potassium sorbate during production and storage.

    Science.gov (United States)

    Oksüztepe, Gülsüm; Gürel Inanli, Ayşe

    2007-08-15

    In this study, microbiological changes during processing and storage of salted-cured trout fillets treated with potassium sorbate were investigated. For this purpose, 10 and 15% (w/w) NaCl and 1, 5 and 10% (w/v) potassium sorbate were applied to the fillets. The processed fillets were vacuum-packed and storage at 4 degrees C. The samples were analyzed in some periods of production and in the storage days of 7, 14, 28, 42, 56, 70 and 84 for numbers of total mesophilic aerob, psycrophylic, yeast and mould. In conclusion, the microbiological quality of all samples treated with 15% NaCl and potassium sorbate were found better. Consequently, it can be concluded that the usage of potassium sorbate may be useful and a synergistic effect between salt and potassium sorbate determined.

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

    Science.gov (United States)

    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

  11. Next generation sequencing for gut microbiome characterization in rainbow trout (Oncorhynchus mykiss) fed animal by-product meals as an alternative to fishmeal protein sources.

    Science.gov (United States)

    Rimoldi, Simona; Terova, Genciana; Ascione, Chiara; Giannico, Riccardo; Brambilla, Fabio

    2018-01-01

    Animal by-product meals from the rendering industry could provide a sustainable and commercially viable alternative to fishmeal (FM) in aquaculture, as they are rich in most essential amino acids and contain important amounts of water-soluble proteins that improve feed digestibility and palatability. Among them, poultry by-product meal (PBM) have given encouraging results in rainbow trout (Oncorhynchus mykiss). However, the introduction of new ingredients in the diet needs to be carefully evaluated since diet is one of the main factors affecting the gut microbiota, which is a complex community that contributes to host metabolism, nutrition, growth, and disease resistance. Accordingly, we investigated the effects of partial replacement of dietary FM with a mix of animal by-product meals and plant proteins on intestinal microbiota composition of rainbow trout in relation to growth and feeding efficiency parameters. We used 1540 trout with an initial mean body weight of 94.6 ± 14.2 g. Fish were fed for 12 weeks with 7 different feed formulations. The growth data showed that trout fed on diets rich in animal by-product meals grew as well as fish fed on control diet, which was rich in FM (37.3%) and PBM-free. High-throughput 16S rRNA gene amplicon sequencing (MiSeq platform, Illumina) was utilised to study the gut microbial community profile. After discarding Cyanobacteria (class Chloroplast) and mitochondria reads a total of 2,701,274 of reads taxonomically classified, corresponding to a mean of 96,474 ± 68,056 reads per sample, were obtained. Five thousand three hundred ninety-nine operational taxonomic units (OTUs) were identified, which predominantly mapped to the phyla of Firmicutes, Proteobacteria, Bacteroidetes and Actinobacteria. The ratio between vegetable and animal proteins proved to play a central role in determining microbiome profiles and Firmicutes and Proteobacteria phyla were particularly discriminatory for diet type in trout. Plant ingredients

  12. Next generation sequencing for gut microbiome characterization in rainbow trout (Oncorhynchus mykiss) fed animal by-product meals as an alternative to fishmeal protein sources

    Science.gov (United States)

    Rimoldi, Simona; Ascione, Chiara; Giannico, Riccardo; Brambilla, Fabio

    2018-01-01

    Animal by-product meals from the rendering industry could provide a sustainable and commercially viable alternative to fishmeal (FM) in aquaculture, as they are rich in most essential amino acids and contain important amounts of water-soluble proteins that improve feed digestibility and palatability. Among them, poultry by-product meal (PBM) have given encouraging results in rainbow trout (Oncorhynchus mykiss). However, the introduction of new ingredients in the diet needs to be carefully evaluated since diet is one of the main factors affecting the gut microbiota, which is a complex community that contributes to host metabolism, nutrition, growth, and disease resistance. Accordingly, we investigated the effects of partial replacement of dietary FM with a mix of animal by-product meals and plant proteins on intestinal microbiota composition of rainbow trout in relation to growth and feeding efficiency parameters. We used 1540 trout with an initial mean body weight of 94.6 ± 14.2 g. Fish were fed for 12 weeks with 7 different feed formulations. The growth data showed that trout fed on diets rich in animal by-product meals grew as well as fish fed on control diet, which was rich in FM (37.3%) and PBM-free. High-throughput 16S rRNA gene amplicon sequencing (MiSeq platform, Illumina) was utilised to study the gut microbial community profile. After discarding Cyanobacteria (class Chloroplast) and mitochondria reads a total of 2,701,274 of reads taxonomically classified, corresponding to a mean of 96,474 ± 68,056 reads per sample, were obtained. Five thousand three hundred ninety-nine operational taxonomic units (OTUs) were identified, which predominantly mapped to the phyla of Firmicutes, Proteobacteria, Bacteroidetes and Actinobacteria. The ratio between vegetable and animal proteins proved to play a central role in determining microbiome profiles and Firmicutes and Proteobacteria phyla were particularly discriminatory for diet type in trout. Plant ingredients

  13. Next generation sequencing for gut microbiome characterization in rainbow trout (Oncorhynchus mykiss fed animal by-product meals as an alternative to fishmeal protein sources.

    Directory of Open Access Journals (Sweden)

    Simona Rimoldi

    Full Text Available Animal by-product meals from the rendering industry could provide a sustainable and commercially viable alternative to fishmeal (FM in aquaculture, as they are rich in most essential amino acids and contain important amounts of water-soluble proteins that improve feed digestibility and palatability. Among them, poultry by-product meal (PBM have given encouraging results in rainbow trout (Oncorhynchus mykiss. However, the introduction of new ingredients in the diet needs to be carefully evaluated since diet is one of the main factors affecting the gut microbiota, which is a complex community that contributes to host metabolism, nutrition, growth, and disease resistance. Accordingly, we investigated the effects of partial replacement of dietary FM with a mix of animal by-product meals and plant proteins on intestinal microbiota composition of rainbow trout in relation to growth and feeding efficiency parameters. We used 1540 trout with an initial mean body weight of 94.6 ± 14.2 g. Fish were fed for 12 weeks with 7 different feed formulations. The growth data showed that trout fed on diets rich in animal by-product meals grew as well as fish fed on control diet, which was rich in FM (37.3% and PBM-free. High-throughput 16S rRNA gene amplicon sequencing (MiSeq platform, Illumina was utilised to study the gut microbial community profile. After discarding Cyanobacteria (class Chloroplast and mitochondria reads a total of 2,701,274 of reads taxonomically classified, corresponding to a mean of 96,474 ± 68,056 reads per sample, were obtained. Five thousand three hundred ninety-nine operational taxonomic units (OTUs were identified, which predominantly mapped to the phyla of Firmicutes, Proteobacteria, Bacteroidetes and Actinobacteria. The ratio between vegetable and animal proteins proved to play a central role in determining microbiome profiles and Firmicutes and Proteobacteria phyla were particularly discriminatory for diet type in trout. Plant

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

    Energy Technology Data Exchange (ETDEWEB)

    Hatch, Douglas R.; Anders, Paul J., Evans, Allen F. (Columbia River Inter-Tribal Fish Commission, Portland, OR)

    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 process 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 based on

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

    Science.gov (United States)

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

    2013-12-01

    through the dynamics of the co-occurring beaver population. The model allowed to us to ask questions critical for designing restoration strategies based on dam building beaver activity, such as what beaver population growth rate is required to develop and maintain floodplain connectivity in an incised system, or what beaver population size is required to increase juvenile steelhead production? The model was sensitive to several variables including beaver colony size, dams and colony dynamics and site fidelity, and thus highlights further research needs to fill critical information gaps.

  16. Comparison of toxin production by clostridium botulinum type E in irradiated and unirradiated vacuum-packed trout (Salmo gairdneri)

    International Nuclear Information System (INIS)

    Hussain, M.; Ehlermann, D.; Diehl, J.F.

    1977-01-01

    Trouts obtained from a nearby Fish farm were slaughtered, gutted, cut into 100g samples and inoculated with 10 1 , 10 3 and 10 5 spores per g of Clostridium botulinum type E. The vacuum-packed samples were stored under melting ice (0 0 C) and at temperatures of 5 0 and 10 0 C for periods of up to 8 weeks. At weekly intervals, occurrence of spoilage and toxin production were determined. Only at 10 0 C storage, the irradiated samples showed toxin production before spoilage was observed. When the fishes were stored at 5 0 C, no toxicity occured before spoilage was observed even in samples treated with doses as high as 200 krad. Samples stored under melting ice, irradiated or unirradiated, never showed toxin production. It is concluded that the radurization of fish at doses of about 100 or 200 krad and at storage temperatures of melting ice or up to 5 0 C is safe with regard to a possible botulism risk. (orig.) [de

  17. Comparison of toxin production by clostridium botulinum type E in irradiated vacuum-packed trout (Salmo gairdneri)

    International Nuclear Information System (INIS)

    Hussain, A.M.; Ehlermann, D.; Diehl, J.F.

    1977-01-01

    Trouts obtained from a nearby Fish farm were slaughtered, gutted, cut into 100 g samples and inoculated with 10 1 , 10 3 and 10 5 spores per g of Clostridium botulinum type E. The vacuum-packed samples were stored under melting ice (0 0 C) and at temperatures of 5 0 and 10 0 C for periods of up to 8 weeks. At weekly intervals, occurrence of spoilage and toxin production were determined. Only at 10 0 C storage, the irradiated samples showed toxin production before spoilage was observed. When the fishes were stored at 5 0 C, no toxicity occurred before spoilage was observed even in samples treated with doses as high as 200 krad. Samples stored under melting ice, irradiated or unirradiated, never showed toxin production. It is concluded that the radurization of fish at doses of about 100 or 200 krad and at storage temperatures of melting ice or up to 5 0 C is safe with regard to a possible botulism risk. (orig.) [de

  18. Comparison of toxin production by clostridium botulinum type E in irradiated and unirradiated vacuum-packed trout (Salmo gairdneri)

    International Nuclear Information System (INIS)

    Hussain, A.M.; Ehlermann, D.; Diehl, J.F.

    1977-01-01

    Trouts obtained from a nearby fish farm were slaughtered, gutted, cut into 100 g samples and inoculated with 10 1 , 10 3 and 10 5 spores per g of Clostridium botulinum type E. The vacuum-packed samples were stored under melting ice (0 0 C) and at temperatures of 5 0 and 10 0 C for periods of up to 8 weeks. At weekly intervals, occurrence of spoilage and toxin production were determined. Only at 10 0 C storage, the irradiated samples showed toxin production before spoilage was observed. When the fishes were stored at 5 0 C, no toxicity occurred before spoilage was observed even in samples treated with doses as high as 200 krad. Samples stored under melting ice, irradiated or unirradiated, never showed toxin production. It is concluded that the radurization of fish at doses of about 100 or 200 krad and at storage temperatures of melting ice or up to 5 0 C is safe with regard to a possible botulism risk. (orig.) [de

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

    Energy Technology Data Exchange (ETDEWEB)

    Hatch, Douglas R.; Branstetter, Ryan (Columbia River Inter-Trial Fish Commission, Portland, OR); Blodgett, Joe (Yakama Nation, Toppenish, WA)

    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) 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. Production of functional sperm by subcutaneous auto-grafting of immature testes in rainbow trout.

    Science.gov (United States)

    Hayashi, Makoto; Sakuma, Daika; Yoshizaki, Goro

    2018-02-01

    Sexually mature individuals are indispensable for breeding programs. Salmonids require a long period before reaching sexual maturity, so we aimed to shorten the period required to obtain functional sperm by grafting immature testicular fragments into mature recipients, which we predicted would allow the grafted testicular fragments to skip the long pre-pubertal period. First, we demonstrated successful subcutaneous auto-grafting of testicular fragments in rainbow trout. Unilateral testectomy was performed, and the isolated immature testicular fragment was auto-grafted into the subcutaneous space along the back of recipient fish. The grafted testicular fragments developed synchronously with the recipients' testis remaining in its body cavity, and both eventually produced functional sperm. Next, immature testicular fragments were auto-grafted into the subcutaneous space of sexually mature males. We achieved this, without immune rejection, by isolating and cryopreserving testes from immature fish, and rearing these unilaterally testectomized fish until sexual maturity. The cryopreserved testes were then auto-grafted into the original, now spermiating fish. The grated immature testicular fragments differentiated and produced functional sperm within 5 months after grafting. By combining this grafting method with a technique to avoid immune rejection, we expect to develop a practical method for producing sperm in a shorter period in salmonids. © 2017 Wiley Periodicals, Inc.

  1. Reproduction impact of mancozeb on rainbow trout (Oncorhynchus mykiss W. and accumulation of its carcinogen metabolite, ethylene thiourea in fish products

    Directory of Open Access Journals (Sweden)

    Milena TZANOVA

    2017-06-01

    Full Text Available Pesticides can be taken up from the water and accumulated in tissues of hydrobionts, often becoming multiplied thousands of times higher in the organism than in the surrounding water. The dithiocarbamate mancozeb is applied in plant protection as fungicide. In recent years the amount of mancozeb used in Europe significantly increased. It is carcinogen due to its metabolite - ethylene thiourea (ETU, which causes thyroid and pituitary tumors. The purpose of this study is to determinate the quantity of ethylene thiourea in products of rainbow trout (Oncorhynchus mykiss W., reared in environment containing permissible, according to the European law, amount of mancozeb. Seeking an answer to the question: is this concentration limit really safe for the reproduction of rainbow trout and can the more toxic metabolite - ETU, be accumulated in the fish eggs and fillet and afterwards make them harmful to the consumers? The study included 3 stages: feeding, analysis of ethylene thiourea in fish eggs and fillet by a new developed and validated HPLC (high performance liquid chromatography method and study of the reproductive indicators. The assays of ETU in all analyzed samples (fish and water were below the limit of quantification of the method, 0.05 mg*l-1, so fish do not accumulate the carcinogen degradation product of mancozeb and the maximum residue level of mancozeb is really safe for the humans as consumers. But these environmental conditions caused reproductive disorders. They can be partly compensated by using sperm activation medium for artificial insemination of trout eggs, but successful fertilization does not guarantee successful hatching, especially of eggs in trout farms with presence of mancozeb in water, even in allowable concentration. The presented results confirm previous investigation, that Salmonidae are very sensitive fish species, react to the lowest deviations in concentration levels of xenobiotics and are used for indicator of non

  2. Coeur d'Alene Tribe Fish, Water and Wildlife Program : Coeur d'Alene Tribe Trout Production Facility Master Plan.

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Ronald L.; Woodward-Lilengreen, Kelly L.; Vitale, Angelo J.

    1999-09-01

    The Northwest Power Planning Council (Council) receives and reviews proposals to mitigate for fish and wildlife losses and refers approved measures to Bonneville Power Administration (BPA) for funding. The Northwest Power Act (Act) calls on the Council to include measures in its Columbia River Basin Fish and Wildlife Program (Program) to address system-wide fish and wildlife losses. The Act further states that the Council may include in its Program measures that provide off-site mitigation--mitigation physically removed from the hydro project(s) that caused the need to mitigate. The Program includes a goal ''to recover and preserve the health of native resident fish injured by the hydropower system, where feasible, and, where appropriate, to use resident fish to mitigate for anadromous fish losses in the system.'' Among those recommended measures are off-site mitigation for losses of anadromous fisheries including the measure under analysis in this Coeur d'Alene Tribe Trout Production Facility Master Plan, proposed by the Coeur d'Alene Tribe. To meet the need for off-site mitigation for anadromous fish losses in the Columbia River Basin in a manner consistent with the objectives of the Council's Fish and Wildlife Program, the Coeur d'Alene Tribe is proposing that the BPA fund the design, construction, operations and maintenance of a trout production facility on the Coeur d'Alene Indian Reservation. Measures for establishing a Coeur d'Alene fish production facility have been a part of the Council's Program since 1987. The Coeur d'Alene Tribe Trout Production Facility is intended to rear and release westslope cutthroat trout into rivers and streams with the express purpose of increasing the numbers of fish spawning, incubating and rearing in the natural environment. It will use the modern technology that hatcheries offer to overcome the mortality resulting from habitat degradation in lakes, rivers, and

  3. Seismology of the Oso-Steelhead landslide

    Science.gov (United States)

    Hibert, C.; Stark, C. P.; Ekström, G.

    2014-12-01

    We carry out a combined analysis of the short- and long-period seismic signals generated by the devastating Oso-Steelhead landslide that occurred on 22 March 2014. The seismic records show that the Oso-Steelhead landslide was not a single slope failure, but a succession of multiple failures distinguished by two major collapses that occurred approximately three minutes apart. The first generated long-period surface waves that were recorded at several proximal stations. We invert these long-period signals for the forces acting at the source, and obtain estimates of the first failure runout and kinematics, as well as its mass after calibration against the mass-center displacement estimated from remote-sensing imagery. Short-period analysis of both events suggests that the source dynamics of the second are more complex than the first. No distinct long-period surface waves were recorded for the second failure, which prevents inversion for its source parameters. However, by comparing the seismic energy of the short-period waves generated by both events we are able to estimate the volume of the second. Our analysis suggests that the volume of the second failure is about 15-30% of the total landslide volume, which is in agreement with ground observations.

  4. Steelhead Critical Habitat, Central Valley - NOAA [ds123

    Data.gov (United States)

    California Natural Resource Agency — This layer depicts areas designated for Steelhead Critical Habitat as well as habitat type and quality in the California Central Valley Evolutionary Significant Unit...

  5. Winter Steelhead Distribution, Pacific Northwest (updated March, 2006)

    Data.gov (United States)

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

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

    Science.gov (United States)

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

    2007-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Hatch, Douglas R.; Branstetter, Ryan; Whiteaker, John (Columbia River Inter-Tribal Fish Commission, Portland, OR)

    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 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. 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 the

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

    Science.gov (United States)

    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.

  9. Barged/In-river steelhead migrant data - Evaluation of methods to reduce straying rates of barged juvenile steelhead

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goals of this study are to develop methods to reduce wandering and straying of steelhead (Oncorhynchus mykiss) that are collected and barged from the Snake River...

  10. Laboratory data on Snake River steelhead - Evaluation of methods to reduce straying rates of barged juvenile steelhead

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goals of this study are to develop methods to reduce wandering and straying of steelhead (Oncorhynchus mykiss) that are collected and barged from the Snake River...

  11. Wenatchee River steelhead reproductive success - Estimate the relative reproductive success of hatchery and wild steelhead in the Wenatchee River, WA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project uses genetic parentage analysis to estimate the relative reproductive success of hatchery and wild steelhead spawning in the Wenatchee River, WA. The...

  12. Kelt reconditioning : A research project to enhance iteroparity in Columbia Basin steelhead (Oncorhynchus mykiss) : Annual report 2000; ANNUAL

    International Nuclear Information System (INIS)

    Evans, Allen F.

    2001-01-01

    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 steelhead 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 behavior and

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

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Allen F.; Beaty, Roy E.; Hatch, Douglas R. (Columbia River Inter-Tribal Fish Commission, Portland, OR)

    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 steelhead 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 behavior and

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

    Science.gov (United States)

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

    2012-01-01

    Lake trout Salvelinus namaycush on thiamine-replete and thiamine-depleted diets were evaluated for the effects of thiamine status on in vivo responses to the T-dependent antigen trinitophenol (TNP)-keyhole limpet hemocyanin (TNP-KLH), the T-independent antigen trinitrophenol-lipolysaccaharide (TNP-LPS), or Dulbecco's phosphate-buffered saline (DPBS; negative control fish). Plasma antibody concentrations were evaluated for possible differences in total anti-TNP activity as well as differences in response kinetics. Associations between anti-TNP activity and muscle and liver thiamine concentrations as well as ratios of muscle-to-liver thiamine to anti-TNP activity were also examined. Thiamine-depleted lake trout that were injected with TNP-LPS exhibited significantly more anti-TNP activity than thiamine-replete fish. The depleted fish injected with TNP-LPS also exhibited significantly different response kinetics relative to thiamine-replete lake trout. No differences in activity or kinetics were observed between the thiamine-replete and -depleted fish injected with TNP-KLH or in the DPBS negative controls. Anti-TNP activity in thiamine-depleted lake trout injected with TNP-KLH was positively associated with muscle thiamine pyrophosphate (thiamine diphosphate; TPP) concentration. A negative association was observed between the ratio of muscle-to-liver TPP and T-independent responses. No significant associations between anti-TNP activity and tissue thiamine concentration were observed in the thiamine-replete fish. We demonstrated that thiamine deficiency leads to alterations in both T-dependent and T-independent immune responses in lake trout.

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

    Science.gov (United States)

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

    2012-12-01

    Lake trout Salvelinus namaycush on thiamine-replete and thiamine-depleted diets were evaluated for the effects of thiamine status on in vivo responses to the T-dependent antigen trinitophenol (TNP)-keyhole limpet hemocyanin (TNP-KLH), the T-independent antigen trinitrophenol-lipolysaccaharide (TNP-LPS), or Dulbecco's phosphate-buffered saline (DPBS; negative control fish). Plasma antibody concentrations were evaluated for possible differences in total anti-TNP activity as well as differences in response kinetics. Associations between anti-TNP activity and muscle and liver thiamine concentrations as well as ratios of muscle-to-liver thiamine to anti-TNP activity were also examined. Thiamine-depleted lake trout that were injected with TNP-LPS exhibited significantly more anti-TNP activity than thiamine-replete fish. The depleted fish injected with TNP-LPS also exhibited significantly different response kinetics relative to thiamine-replete lake trout. No differences in activity or kinetics were observed between the thiamine-replete and -depleted fish injected with TNP-KLH or in the DPBS negative controls. Anti-TNP activity in thiamine-depleted lake trout injected with TNP-KLH was positively associated with muscle thiamine pyrophosphate (thiamine diphosphate; TPP) concentration. A negative association was observed between the ratio of muscle-to-liver TPP and T-independent responses. No significant associations between anti-TNP activity and tissue thiamine concentration were observed in the thiamine-replete fish. We demonstrated that thiamine deficiency leads to alterations in both T-dependent and T-independent immune responses in lake trout.

  16. Assess Current and Potential Salmonid Production in Rattlesnake Creek in Association with Restoration Efforts, US Geological Survey Report, 2004-2005 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Allen, M. Brady; Connolly, Patrick J.; Jezorek, Ian G. (US Geological Survey, Western Fisheries Research Center, Columbia River Research Laboratory, Cook, WA)

    2006-06-01

    This project was designed to document existing habitat conditions and fish populations within the Rattlesnake Creek watershed (White Salmon River subbasin, Washington) before major habitat restoration activities are implemented and prior to the reintroduction of salmon and steelhead above Condit Dam. Returning adult salmon Oncorhynchus spp. and steelhead O. mykiss have not had access to Rattlesnake Creek since 1913. An assessment of resident trout populations should serve as a good surrogate for evaluation of factors that would limit salmon and steelhead production in the watershed. Personnel from United States Geological Survey's Columbia River Research Laboratory (USGS-CRRL) attended to three main objectives of the Rattlesnake Creek project. The first objective was to characterize stream and riparian habitat conditions. This effort included measures of water quality, water quantity, stream habitat, and riparian conditions. The second objective was to determine the status of fish populations in the Rattlesnake Creek drainage. To accomplish this, we derived estimates of salmonid population abundance, determined fish species composition, assessed distribution and life history attributes, obtained tissue samples for genetic analysis, and assessed fish diseases in the watershed. The third objective was to use the collected habitat and fisheries information to help identify and prioritize areas in need of restoration. As this report covers the fourth year of a five-year study, it is largely restricted to describing our efforts and findings for the first two objectives.

  17. Assess Current and Potential Salmonid Production in Rattlesnake Creek Associated with Restoration Efforts; US Geological Survey Reports, 2002-2003 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Connolly, Patrick J. (US Geological Survey, Columbia River Research Laboratory, Western Fisheries Research Center, Cook, WA)

    2003-12-01

    This project was designed to document existing habitat conditions and fish populations within the Rattlesnake Creek watershed (White Salmon River subbasin, Washington) before major habitat restoration activities are implemented and prior to the reintroduction of salmon and steelhead above Condit Dam. Returning adult salmon Oncorhynchus spp. and steelhead O. mykiss have not had access to Rattlesnake Creek since 1913. An assessment of resident trout populations should serve as a good surrogate for evaluation of factors that would limit salmon and steelhead production in the watershed. Personnel from United States Geological Survey's Columbia River Research Laboratory (USGS-CRRL) attend to three main objectives of the Rattlesnake Creek project. The first is to characterize stream and riparian habitat conditions. This effort includes measures of water quality, water quantity, stream habitat, and riparian conditions. The second objective is to determine the status of fish populations in the Rattlesnake Creek drainage. To accomplish this, we derived estimates of salmonid population abundance, determined fish species composition, assessed distribution and life history attributes, obtained tissue samples for genetic analysis, and assessed fish diseases in the watershed. The third objective is to use the collected habitat and fisheries information to help identify and prioritize areas in need of restoration. As this report covers the second year of at least a three-year study, it is largely restricted to describing our efforts and findings for the first two objectives.

  18. Assess Current and Potential Salmonid Production in Rattlesnake Creek in Association with Restoration Effors; US Geological Survey Reports, 2003-2004 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Allen, M. Brady; Connolly, Patrick J.; Munz, Carrie S. (US Geological Survey, Western Fisheries Research Center, Columbia River Research Laboratory, Cook, WA)

    2006-02-01

    This project was designed to document existing habitat conditions and fish populations within the Rattlesnake Creek watershed (White Salmon River subbasin, Washington) before major habitat restoration activities are implemented and prior to the reintroduction of salmon and steelhead above Condit Dam. Returning adult salmon Oncorhynchus spp. and steelhead O. mykiss have not had access to Rattlesnake Creek since 1913. An assessment of resident trout populations should serve as a good surrogate for evaluation of factors that would limit salmon and steelhead production in the watershed. Personnel from United States Geological Survey's Columbia River Research Laboratory (USGS-CRRL) attend to three main objectives of the Rattlesnake Creek project. The first is to characterize stream and riparian habitat conditions. This effort includes measures of water quality, water quantity, stream habitat, and riparian conditions. The second objective is to determine the status of fish populations in the Rattlesnake Creek drainage. To accomplish this, we derived estimates of salmonid population abundance, determined fish species composition, assessed distribution and life history attributes, obtained tissue samples for genetic analysis, and assessed fish diseases in the watershed. The third objective was to use the collected habitat and fisheries information to help identify and prioritize areas in need of restoration. As this report covers the third year of at least a five-year study, it is largely restricted to describing our efforts and findings for the first two objectives.

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

    Science.gov (United States)

    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...

  20. Comparing the effects of feeding a grain- or a fish meal-based diet on water quality, waste production, and rainbow trout Oncorhynchus mykiss performance within low exchange water recirculating aquaculture systems

    Science.gov (United States)

    Feeding a fish meal-free grain-based diet (GB) was compared to feeding a fish meal-based diet (FM) relative to water quality criteria, waste production, water treatment process performance, and rainbow trout Oncorhynchus mykiss performance within six replicated water recirculating aquaculture system...

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

    Energy Technology Data Exchange (ETDEWEB)

    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. 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.

  2. Factors driving spatial and temporal variation in production and production/biomass ratio of stream-resident brown trout (Salmo trutta) in Cantabrian streams

    Science.gov (United States)

    Lobon-Cervia, J.; Gonzalez, G.; Budy, P.

    2011-01-01

    1.The objective was to identify the factors driving spatial and temporal variation in annual production (PA) and turnover (production/biomass) ratio (P/BA) of resident brown trout Salmo trutta in tributaries of the Rio Esva (Cantabrian Mountains, Asturias, north-western Spain). We examined annual production (total production of all age-classes over a year) (PA) and turnover (P/BA) ratios, in relation to year-class production (production over the entire life time of a year-class) (PT) and turnover (P/BT) ratio, over 14years at a total of 12 sites along the length of four contrasting tributaries. In addition, we explored whether the importance of recruitment and site depth for spatial and temporal variations in year-class production (PT), elucidated in previous studies, extends to annual production. 2.Large spatial (among sites) and temporal (among years) variation in annual production (range 1.9-40.3gm-2 per year) and P/BA ratio (range 0.76-2.4per year) typified these populations, values reported here including all the variation reported globally for salmonids streams inhabited by one or several species. 3.Despite substantial differences among streams and sites in all production attributes, when all data were pooled, annual (PA) and year-class production (PT) and annual (P/BA) and year-class P/BT ratios were tightly linked. Annual (PA) and year-class production (PT) were similar but not identical, i.e. PT=0.94 PA, whereas the P/BT ratios were 4+P/BA ratios. 4.Recruitment (Rc) and mean annual density (NA) were major density-dependent drivers of production and their relationships were described by simple mathematical models. While year-class production (PT) was determined (R2=70.1%) by recruitment (Rc), annual production (PA) was determined (R2=60.3%) by mean annual density (NA). In turn, variation in recruitment explained R2=55.2% of variation in year-class P/BT ratios, the latter attaining an asymptote at P/BT=6 at progressively higher levels of recruitment

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hatch, Douglas R. [Columbia River Inter-Tribal Fish Commission

    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 kelt 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 subbasin

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

    Energy Technology Data Exchange (ETDEWEB)

    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 juvenile 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

  6. EFFECT OF TROUT PRODUCTION IN CONCRETE PONDS WITH A CASCADING FLOW OF WATER ON PHYSICAL AND CHEMICAL PROPERTY OF WATER

    Directory of Open Access Journals (Sweden)

    Marcin Sidoruk

    2014-10-01

    Full Text Available Fish rearing causes changes in water quality due to the use of feed, mineral and organic fertilizers, pharmaceuticals and disinfectants. Rational fishery management aims to maintain or restore the quality of water in natural ecosystems. Cultures produce a certain amount of waste and pollutants released into the environment with waters departing from ponds, but their harmfulness depends on the conditions and type of farming. Studies on the assessment of the effects of rearing trout on physical and chemical properties of surface water were carried out in 2010-2012. Were chosen trout farm located in the Pomeranian province about 36 miles southeast of Słupsk. Water samples for physical and chemical analysis were collected every two months (a total of 12 sets samples collected and labeled them: temperature [°C], dissolved oxygen [mg · dm-3], oxygen saturation [%] electrolytic conductivity [S · cm-1], pH, redox potential [mV] and BOD5 and CODCr. The study showed that the water used to supply breeding facilities meet the requirements to be met which are inland water salmonid habitat. Only periodically for BOD5 standards have been slightly exceeded. After passing through the joints deterioration of water quality did not cause a change in the quality of the class, if only temporarily BOD5 ratio were lower in its quality from the first to the third class.

  7. Nisin Z Production by Lactococcus lactis subsp. cremoris WA2-67 of Aquatic Origin as a Defense Mechanism to Protect Rainbow Trout (Oncorhynchus mykiss, Walbaum) Against Lactococcus garvieae.

    Science.gov (United States)

    Araújo, Carlos; Muñoz-Atienza, Estefanía; Pérez-Sánchez, Tania; Poeta, Patrícia; Igrejas, Gilberto; Hernández, Pablo E; Herranz, Carmen; Ruiz-Zarzuela, Imanol; Cintas, Luis M

    2015-12-01

    Probiotics represent an alternative to chemotherapy and vaccination to control fish diseases, including lactococcosis caused by Lactococcus garvieae. The aims of this study were (i) to determine the in vitro probiotic properties of three bacteriocinogenic Lactococcus lactis subsp. cremoris of aquatic origin, (ii) to evaluate in vivo the ability of L. cremoris WA2-67 to protect rainbow trout (Oncorhynchus mykiss, Walbaum) against infection by L. garvieae, and (iii) to demonstrate the role of nisin Z (NisZ) production as an anti-infective mechanism. The three L. cremoris strains survived in freshwater at 18 °C for 7 days, withstood exposure to pH 3.0 and 10 % (v/v) rainbow trout bile, and showed different cell surface hydrophobicity (37.93-58.52 %). The wild-type NisZ-producer L. cremoris WA2-67 and its non-bacteriocinogenic mutant L. cremoris WA2-67 ∆nisZ were administered orally (10(6) CFU/g) to rainbow trout for 21 days and, subsequently, fish were challenged with L. garvieae CLG4 by the cohabitation method. The fish fed with the bacteriocinogenic strain L. cremoris WA2-67 reduced significantly (p trout against infection with the invasive pathogen L. garvieae and the relevance of NisZ production as an anti-infective mechanism. This is the first report demonstrating the effective in vivo role of LAB bacteriocin (NisZ) production as a mechanism to protect fish against bacterial infection. Our results suggest that the wild-type NisZ-producer strain L. cremoris WA2-67 could be used in fish farming to prevent lactococcosis in rainbow trout.

  8. Investigations into the Early Life History of Naturally Produced Spring Chinook Salmon and Summer Steelhead in the Grande Ronde River Basin : Annual Report 2000 : Project Period 1 October 1999 to 30 November 2000.

    Energy Technology Data Exchange (ETDEWEB)

    Monzyk, Fred R.

    2002-06-01

    The authors determined migration timing and abundance of juvenile spring chinook salmon Oncorhynchus tshawytscha and juvenile steelhead/rainbow trout O. mykiss from three populations in the Grande Ronde River basin. 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 July through January with a peak in the fall. A late migrant group descended from upper rearing areas from February through June with a peak in the spring.

  9. Investigations into the early life history of naturally produced spring chinook salmon and summer steelhead in the Grande Ronde River Basin : annual report 2000 : project period 1 October 1999 to 30 November 2000.; ANNUAL

    International Nuclear Information System (INIS)

    Monzyk, Fred R.; United States. Bonneville Power Administration. Environment, Fish and Wildlife.

    2002-01-01

    The authors determined migration timing and abundance of juvenile spring chinook salmon Oncorhynchus tshawytscha and juvenile steelhead/rainbow trout O. mykiss from three populations in the Grande Ronde River basin. 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 July through January with a peak in the fall. A late migrant group descended from upper rearing areas from February through June with a peak in the spring

  10. Larger eggs in resident brown trout living in sympatry with anadromous brown trout

    DEFF Research Database (Denmark)

    Olofsson, H.; Mosegaard, Henrik

    1999-01-01

    Freshwater resident brown trout (Salmo trutta L.) in the stream Jorlandaan (southwestern Sweden) had larger eggs (range of actual mean egg wet weights, 65.9-108.5 mg) than both sympatric migratory trout (76.8-84.2 mg) and trout from five other Swedish streams with allopatric resident (23.7-80.1 mg......) or migratory populations (44.5-121.9 mg), after accounting for differences in body size. In Jorlandaan, some resident females even had a larger absolute mean egg weight than any of the migratory females found in the stream Resident trout had low absolute fecundity, and our data suggest that resident females...... in Jorlandan produce large eggs at the expense of their fecundity The extremely large relative egg size in resident Jorlandaan females suggests that the production of large offspring enhances fitness, possibly through increased fry survival....

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

    Science.gov (United States)

    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.

  12. Monitoring of downstream salmon and steelhead trout at federal hydroelectric facilities, annual report 2001.; ANNUAL

    International Nuclear Information System (INIS)

    United States. Bonneville Power Administration. Division of Fish and Wildlife.

    2002-01-01

    The seaward migration of juvenile salmonids was monitored by the Pacific States Marine Fisheries Commission (PSMFC) at John Day Dam, located at river mile 216, and at Bonneville Dam, located at river mile 145 on the Columbia River (Figure 1). The PSMFC Smolt Monitoring Project is part of a larger Smolt Monitoring Program (SMP) coordinated by the Fish Passage Center (FPC) for the Columbia Basin Fish and Wildlife Authority. This program is carried out under the auspices of the Northwest Power Planning Council's Fish and Wildlife Program and is funded by the Bonneville Power Administration

  13. Physiological indices of seawater readiness in postspawning steelhead kelts

    Science.gov (United States)

    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.

  14. Effect of modified atmosphere and vacuum packaging on TVB-N production of rainbow trout (Oncorhynchus mykiss) and carp (Cyprinus carpio) cuts

    Science.gov (United States)

    Babić Milijašević, J.; Milijašević, M.; Đinović-Stojanović, J.; Vranić, D.

    2017-09-01

    The aim of our research was to examine the influence of packaging in modified atmosphere and vacuum on the total volatile basic nitrogen (TVB-N) content in muscle of rainbow trout (Oncorhynchus mykiss) and common carp (Cyprinus carpio), as well as to determine the most suitable gas mixtures for packing of these freshwater species. Three sample groups of trout and carp cuts were investigated. The two groups were packaged in modified atmosphere with different gas ratios: 90%CO2+10%N2 (MAP 1) and 60%CO2+40%N2 (MAP 2), whereas the third group of fish cuts were vacuum packaged. During trials, the trout and carp cuts were stored in refrigerator at 3°C±0.5°C. Determination of TVB-N was performed on 1, 4, 7, 9, 12 and 14 days of storage. The obtained results indicate that the investigated mixtures of gases and vacuum had a significant influence on the values of TVB-N in trout and carp cuts. The lowest increase in TVB-N was established in trout and carp cuts packaged in MAP 1, whereas the highest increase was established in vacuum packaged cuts. Based on the obtained results, it can be concluded that the gas mixture consisting of 90% CO2 and 10% N2 was the most suitable for packaging of fresh trout and carp cuts in terms of TVB-N value.

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

    Science.gov (United States)

    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

  16. Trout Stream Special Regulations

    Data.gov (United States)

    Minnesota Department of Natural Resources — This layer shows Minnesota trout streams that have a special regulation as described in the 2006 Minnesota Fishing Regulations. Road crossings were determined using...

  17. Studies on Some Productive and Reproductive Performance in Female Rainbow Trout (Oncorhynchus Mykiss and Brown Trout (Salmo Trutta Fario at Four Years of Age, From Fiad-Telcişor Salmonids Complex, Bistriţa-Năsăud County

    Directory of Open Access Journals (Sweden)

    Daniel Cocan

    2010-10-01

    Full Text Available Consumer preferences regarding the various species of fish or aquatic organisms are highly variable. The criteria by which they orient are represented by: the price, organoleptic characteristics, healing and nutritional properties of meat. Today it is known that a high consumption of fish meat has a beneficial role in human health. Moreover, statistics indicates a high level of life expectancy in countries with tradition in terms of fish consumption, e.g. NorthEuropean and Asian countries. Statistics shows a high consumption of ocean fish and different species of salmonid family. The culture and intensive fish farming represents an alternative to the requirements of the fish market. The salmonids farmers focus their efforts to obtain high yields of high quality, in conditions of maximum economic efficiency. In Romania, the predominant specie encountered in salmonis farms is rainbow trout (Oncorhynchus mykiss. It is successfully reared because of its plasticity and resistance to changes in environmental conditions and disease, and efficient feed-conversion. For restocking mountain water with biological material, some trout farms operate successfully brown trout (Salmo trutta fario, a less effective specie for meat production, due to slow growth and development and low resistance to changing environmental factors. Profitability of fish production depends on the propagation processes, fish growth and developments, and supplying optimal environmental conditions for enhancement of the biological potential. The artificial reproduction of salmonids, involves several technological operations for achieving outstanding results on fisheries production. Of these operations, critical is the selection and improvement of breeding.

  18. Estrogenicity and intersex in juvenile rainbow trout (Oncorhynchus mykiss) exposed to Pine/Eucalyptus pulp and paper production effluent in Chile

    International Nuclear Information System (INIS)

    Chiang, Gustavo; Barra, Ricardo; Díaz-Jaramillo, Mauricio; Rivas, Meyling; Bahamonde, Paulina; Munkittrick, Kelly R.

    2015-01-01

    Highlights: • Juvenile rainbow were exposed to Pine and Eucalyptus PPME along with an in situ bioassay downstream of the combined discharge. • Fish exposed to PPME showed induced levels of plasma vitellogenin and female gonad maturation. • Male fish showed intersex characteristics in laboratory and in situ assays. • Tertiary treated PPME from Eucalyptus production have stronger estrogenic effects on juvenile fish. - Abstract: Pulp and paper mill effluents (PPMEs) have been shown to increase gonad size, cause early maturation, and disrupt hormone functions in native and non-native Chilean fish. In this study, we assessed reproductive (plasma vitellogenin; VTG, gonad development) and metabolic (ethoxyresorufin-O-deethylase activity; EROD) end points, relative liver size (LSI) and condition factor (K) of juvenile female and male rainbow trout exposed to effluents. Unlike previous studies, which have focus either on the specific effects of effluent on fish in laboratory exposures or biotic population statuses downstream of discharge sites, we simultaneously assessed the impacts of PPMES on trout using two approaches: (1) laboratory exposures of tertiary treated PPME produced from processing Eucalyptus globulus or Pinus radiata; and (2) in situ bioassay downstream of the combined discharge of the same pulp mill. Despite an increase in the average gonadosomatic index (GSI) in exposed fish, no statistical differences in gonad size between exposed and unexposed individuals was detected. However, both female and male fish exposed to effluents showed significantly higher concentrations of plasma VTG, so more in fish exposed to Eucalyptus-based effluent when compared to Pinus PPME. In addition, male fish showed intersex characteristics in all exposure assays (Eucaliptus and Pinus) and, despite the low concentration of effluent in the river (<1% [v/v]), similar responses were observed in the caged fish. Finally, EROD activity was induced in both in situ exposures and

  19. Estrogenicity and intersex in juvenile rainbow trout (Oncorhynchus mykiss) exposed to Pine/Eucalyptus pulp and paper production effluent in Chile

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Gustavo, E-mail: gchiang@centromeri.cl [Canadian Rivers Institute and Department of Biology, University of New Brunswick, Saint John, NB E2L 4L5 (Canada); Barra, Ricardo [Aquatic Systems Research Unit, EULA–Chile Environmental Sciences Centre, University of Concepción, Concepcion (Chile); Díaz-Jaramillo, Mauricio [Laboratorio de Ecotoxicología y Contaminación Ambiental (ECoA), IIMyC-CONICET-UNMdP, Mar del Plata (Argentina); Rivas, Meyling [Department of Zoology, Faculty of Natural and Oceanographic Sciences, University of Concepcion, Concepcion (Chile); Bahamonde, Paulina; Munkittrick, Kelly R. [Canadian Rivers Institute and Department of Biology, University of New Brunswick, Saint John, NB E2L 4L5 (Canada)

    2015-07-15

    Highlights: • Juvenile rainbow were exposed to Pine and Eucalyptus PPME along with an in situ bioassay downstream of the combined discharge. • Fish exposed to PPME showed induced levels of plasma vitellogenin and female gonad maturation. • Male fish showed intersex characteristics in laboratory and in situ assays. • Tertiary treated PPME from Eucalyptus production have stronger estrogenic effects on juvenile fish. - Abstract: Pulp and paper mill effluents (PPMEs) have been shown to increase gonad size, cause early maturation, and disrupt hormone functions in native and non-native Chilean fish. In this study, we assessed reproductive (plasma vitellogenin; VTG, gonad development) and metabolic (ethoxyresorufin-O-deethylase activity; EROD) end points, relative liver size (LSI) and condition factor (K) of juvenile female and male rainbow trout exposed to effluents. Unlike previous studies, which have focus either on the specific effects of effluent on fish in laboratory exposures or biotic population statuses downstream of discharge sites, we simultaneously assessed the impacts of PPMES on trout using two approaches: (1) laboratory exposures of tertiary treated PPME produced from processing Eucalyptus globulus or Pinus radiata; and (2) in situ bioassay downstream of the combined discharge of the same pulp mill. Despite an increase in the average gonadosomatic index (GSI) in exposed fish, no statistical differences in gonad size between exposed and unexposed individuals was detected. However, both female and male fish exposed to effluents showed significantly higher concentrations of plasma VTG, so more in fish exposed to Eucalyptus-based effluent when compared to Pinus PPME. In addition, male fish showed intersex characteristics in all exposure assays (Eucaliptus and Pinus) and, despite the low concentration of effluent in the river (<1% [v/v]), similar responses were observed in the caged fish. Finally, EROD activity was induced in both in situ exposures and

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

    Indian Academy of Sciences (India)

    Molecular Genetics Laboratory, Directorate of Coldwater Fisheries Research, Bhimtal 263 ... Mir J. I., Ali S., Patiyal R. S. and Singh A. K. 2015 Molecular characterization of rainbow trout, ..... 5 × 106 MCMC repeats for final sampling of data. .... enhancing aquaculture productivity in the coldwater regions. ... simulation study.

  1. Idaho Habitat/Natural Production Monitoring, Pt. I: General Monitoring Subproject : Annual Progress Report 1990.

    Energy Technology Data Exchange (ETDEWEB)

    Rich, Bruce A.; Scully, Richard J.; Petrosky, Charles Edward

    1992-01-01

    The Idaho Department of Fish and Game (IDFG) has been monitoring and evaluating proposed and existing habitat improvement projects for rainbow-steelhead trout Oncorhynchus mykiss, hereafter called steelhead, and chinook salmon O. tshawytscha, hereafter called chinook, in the Clearwater and Salmon River drainages for the past seven years. Projects included in the evaluation are funded by, or proposed for funding by, the Bonneville Power Administration (BPA) under the Northwest Power Planning Act as off-site mitigation for downstream hydropower development on the Snake and Columbia rivers. This evaluation project is also funded under the same authority (Fish and Wildlife Program, Northwest Power Planning Council). A mitigation record is being developed using increased carrying capacity and/or survival as the best measure of benefit from a habitat enhancement project. Determination of full benefit from a project depends on completion or maturation of the project and presence of adequate numbers of fish to document actual increases in fish production. The depressed status of upriver anadromous stocks has precluded measuring full benefits of any habitat project in Idaho. Partial benefit is credited to the mitigation record in the interim period of run restoration.

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

    International Nuclear Information System (INIS)

    Contor, C.R.; Hoverson, E.; Kissner, P.; Volkman, J.

    1996-04-01

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

  3. First evidence of successful natural reproduction by planted lake trout in Lake Huron

    Science.gov (United States)

    Nester, Robert T.; Poe, Thomas P.

    1984-01-01

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

  4. Identification of differentially expressed genes of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) in response to Tetracapsuloides bryosalmonae (Myxozoa).

    Science.gov (United States)

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

    2015-03-01

    Tetracapsuloides bryosalmonae Canning et al., 1999 (Myxozoa) is the causative agent of proliferative kidney disease in various species of salmonids in Europe and North America. We have shown previously that the development and distribution of the European strain of T. bryosalmonae differs in the kidney of brown trout (Salmo trutta) Linnaeus, 1758 and rainbow trout (Oncorhynchus mykiss) Walbaum, 1792, and that intra-luminal sporogonic stages were found in brown trout but not in rainbow trout. We have now compared transcriptomes from kidneys of brown trout and rainbow trout infected with T. bryosalmonae using suppressive subtractive hybridization (SSH). The differentially expressed transcripts produced by SSH were cloned, transformed, and tested by colony PCR. Differential expression screening of PCR products was validated using dot blot, and positive clones having different signal intensities were sequenced. Differential screening and a subsequent NCBI-BLAST analysis of expressed sequence tags revealed nine clones expressed differently between both fish species. These differentially expressed genes were validated by quantitative real-time PCR of kidney samples from both fish species at different time points of infection. Expression of anti-inflammatory (TSC22 domain family protein 3) and cell proliferation (Prothymin alpha) genes were upregulated significantly in brown trout but downregulated in rainbow trout. The expression of humoral immune response (immunoglobulin mu) and endocytic pathway (Ras-related protein Rab-11b) genes were significantly upregulated in rainbow trout but downregulated in brown trout. This study suggests that differential expression of host anti-inflammatory, humoral immune and endocytic pathway responses, cell proliferation, and cell growth processes do not inhibit the development of intra-luminal sporogonic stages of the European strain of T. bryosalmonae in brown trout but may suppress it in rainbow trout.

  5. Lake Roosevelt Rainbow Trout Habitat/Passage Improvement Project, Annual Report 2002-2003.

    Energy Technology Data Exchange (ETDEWEB)

    Sears, Sheryl

    2004-01-01

    The construction of Chief Joseph and Grand Coulee Dams completely and irrevocably blocked anadromous fish migrations to the Upper Columbia River. Historically this area hosted vast numbers of salmon returning to their natal waters to reproduce and die. For the native peoples of the region, salmon and steelhead were a principle food source, providing physical nourishment and spiritual sustenance, and contributing to the religious practices and the cultural basis of tribal communities. The decaying remains of spawned-out salmon carcasses contributed untold amounts of nutrients into the aquatic, aerial, and terrestrial ecosystems of tributary habitats in the upper basin. Near the present site of Kettle Falls, Washington, the second largest Indian fishery in the state existed for thousands of years. Returning salmon were caught in nets and baskets or speared on their migration to the headwater of the Columbia River in British Columbia. Catch estimates at Kettle Falls range from 600,000 in 1940 to two (2) million around the turn of the century (UCUT, Report No.2). The loss of anadromous fish limited the opportunities for fisheries management and enhancement exclusively to those actions addressed to resident fish. The Lake Roosevelt Rainbow Trout Habitat/Passage Improvement Project is a mitigation project intended to enhance resident fish populations and to partially mitigate for anadromous fish losses caused by hydropower system impacts. This substitution of resident fish for anadromous fish losses is considered in-place and out-of-kind mitigation. Upstream migration and passage barriers limit the amount of spawning and rearing habitat that might otherwise be utilized by rainbow trout. The results of even limited stream surveys and habitat inventories indicated that a potential for increased natural production exists. However, the lack of any comprehensive enhancement measures prompted the Upper Columbia United Tribes Fisheries Center (UCUT), Colville Confederated

  6. Lake Roosevelt Rainbow Trout Habitat/Passage Improvement Project, Annual Report 2001-2002.

    Energy Technology Data Exchange (ETDEWEB)

    Sears, Sheryl

    2003-01-01

    The construction of Chief Joseph and Grand Coulee Dams completely and irrevocably blocked anadromous fish migrations to the Upper Columbia River. Historically this area hosted vast numbers of salmon returning to their natal waters to reproduce and die. For the native peoples of the region, salmon and steelhead were a principle food source, providing physical nourishment and spiritual sustenance, and contributing to the religious practices and the cultural basis of tribal communities. The decaying remains of spawned-out salmon carcasses contributed untold amounts of nutrients into the aquatic, aerial, and terrestrial ecosystems of tributary habitats in the upper basin. Near the present site of Kettle Falls, Washington, the second largest Indian fishery in the state existed for thousands of years. Returning salmon were caught in nets and baskets or speared on their migration to the headwater of the Columbia River in British Columbia. Catch estimates at Kettle Falls range from 600,000 in 1940 to two (2) million around the turn of the century (UCUT, Report No.2). The loss of anadromous fish limited the opportunities for fisheries management and enhancement exclusively to those actions addressed to resident fish. The Lake Roosevelt Rainbow Trout Habitat/Passage Improvement Project is a mitigation project intended to enhance resident fish populations and to partially mitigate for anadromous fish losses caused by hydropower system impacts. This substitution of resident fish for anadromous fish losses is considered in-place and out-of-kind mitigation. Upstream migration and passage barriers limit the amount of spawning and rearing habitat that might otherwise be utilized by rainbow trout. The results of even limited stream surveys and habitat inventories indicated that a potential for increased natural production exists. However, the lack of any comprehensive enhancement measures prompted the Upper Columbia United Tribes Fisheries Center (UCUT), Colville Confederated

  7. COLUMBIA RIVER BASIN SALMON AND STEELHEAD: Federal Agencies' Recovery Responsibilities, Expenditures and Actions

    National Research Council Canada - National Science Library

    2002-01-01

    ..., and unfavorable weather and ocean conditions. The population decline has resulted in the listing of 12 salmon and steelhead populations in the basin as threatened or endangered under the Endangered...

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

    Science.gov (United States)

    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.

  9. Case report of an unusual heart abnormality in Rainbow trout (Oncorhynchus mykiss)

    Science.gov (United States)

    An unusual heart abnormality in rainbow trout Oncorhynchus mykiss was recently observed. During the course of a standard hydrogen peroxide treatment (100 ppm) of production rainbow trout (mean weight, 2-3 g) affected with an external bacterial infection, a small percentage of fish exhibited morbidi...

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

    Science.gov (United States)

    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

  11. Trout in the Classroom

    Science.gov (United States)

    Heath, Thomas

    2014-05-01

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

  12. Plump Cutthroat Trout and Thin Rainbow Trout in a Lentic Ecosystem

    OpenAIRE

    Courtney, Joshua; Abbott, Jessica; Schmidt, Kerri; Courtney, Michael

    2012-01-01

    Background: Much has been written about introduced rainbow trout (Oncorhynchus mykiss) interbreeding and outcompeting cutthroat trout (Oncorhynchus clarkii). However, the specific mechanisms by which rainbow trout and their hybrids outcompete cutthroat trout have not been thoroughly explored, and the published data is limited to lotic ecosystems. Materials and Methods: Samples of rainbow trout and cutthroat trout were obtained from a lentic ecosystem by angling. The total length and weight of...

  13. Influences of incubation temperature and various saccharides on the production of organic acids and gases by gut microbes of rainbow trout Oncorhynchus mykiss in a micro-scale batch culture.

    Science.gov (United States)

    Kihara, M; Sakata, T

    2001-08-01

    We studied the influence of incubation temperature and additional saccharides on the metabolism of hindgut microbes of the rainbow trout Oncorhynchus mykiss in a 50 microl-scale batch culture system. Intestinal contents of rainbow trout reared at 15 degrees C were incubated with glucose, lactosucrose, sodium alginate or colloidal chitin (each 10 g/l) at 15 degrees C or 25 degrees C for 12 h. Levels of organic acids at 0 h and 12 h of incubation were quantified with HPLC. We also monitored gas release from these cultures during incubation. The main product was iso-butyric acid, except for the cultures with colloidal chitin where no net production of organic acids was observed. We detected higher levels of iso-butyric acid in cultures with lactosucrose than in the other cultures. Net production of this acid was less in cultures with colloidal chitin than in blank cultures. The volume of released gas was larger when incubated at 25 degrees C than at 15 degrees C. Cultures with colloidal chitin released more gas than blank cultures when they were incubated at 15 degrees C. Cultures with sodium alginate released less gas than blank cultures irrespective of incubation temperature. These results indicate that the hindgut microbes of this carnivorous fish mainly produce branched-chain fatty acids, very likely by microbial digestion of nitrogenous materials rather than saccharides. However, additional saccharides affected production of branched-chain fatty acids. The influence of incubation temperature in the present study also suggested that the environmental temperature of host fish should affect microbial digestion in the fish gut.

  14. Idaho Natural Production Monitoring and Evaluation : Annual Progress Report February 1, 2007 - January 31, 2008.

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, Timothy; Johnson, June; Putnam, Scott

    2008-12-01

    Populations of anadromous salmonids in the Snake River basin declined precipitously following the construction of hydroelectric dams in the Snake and Columbia rivers. Raymond (1988) documented a decrease in survival of emigrating steelhead trout Oncorhynchus mykiss and Chinook salmon O. tshawytscha from the Snake River following the construction of dams on the lower Snake River during the late 1960s and early 1970s. Although Raymond documented some improvements in survival through the early 1980s, anadromous populations remained depressed and declined even further during the 1990s (Petrosky et al. 2001; Good et al. 2005). The effect was disastrous for all anadromous salmonid species in the Snake River basin. Coho salmon O. kisutch were extirpated from the Snake River by 1986. Sockeye salmon O. nerka almost disappeared from the system and were declared under extreme risk of extinction by authority of the Endangered Species Act (ESA) in 1991. Chinook salmon were classified as threatened with extinction in 1992. Steelhead trout were also classified as threatened in 1997. Federal management agencies in the basin are required to mitigate for hydroelectric impacts and provide for recovery of all ESA-listed populations. In addition, the Idaho Department of Fish and Game (IDFG) has the long-term goal of preserving naturally reproducing salmon and steelhead populations and recovering them to levels that will provide a sustainable harvest (IDFG 2007). Management to achieve these goals requires an understanding of how salmonid populations function (McElhany et al. 2000) as well as regular status assessments. Key demographic parameters, such as population density, age composition, recruits per spawner, and survival rates must be estimated annually to make such assessments. These data will guide efforts to meet mitigation and recovery goals. The Idaho Natural Production Monitoring and Evaluation Project (INPMEP) was developed to provide this information to managers. The Snake

  15. 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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  17. CHEMICAL COMPOSITION AND ENERGY VALUE IN THE MEAT OF THE MACEDONIAN AND OHRID TROUT

    Directory of Open Access Journals (Sweden)

    Aleksandar SAVESKI

    2017-03-01

    Full Text Available The aim of this research is to conduct a comparative analysis and to verify the quality properties of meat of the Macedonian trout (Salmo macedonicus and the Ohrid trout (Salmo letnica, from aquaculture production, bred on a fish farm under controlled conditions. In order to determine the quality of meat of the Macedonian and Ohrid trout, analyses of the chemical composition have been conducted: the amount of proteins, fat, water, minerals, as well as a determination of the energy value of the meat. The analyses have been made on samples from Macedonian and Ohrid trout, with size of consumption between 200g and 300g. By these analyses, it has been confirmed that in the meat of the Macedonian trout, the amount of water is 77.122%, 17.800% proteins, 3.333% fat and 1.667% minerals, whereas in the meat of the Ohrid trout 75.923% water, 16.783% proteins, 5.403% fat and 1.080% minerals. Though the established difference in the amount of water and fat is not significant, the differences determined in the contents of proteins and minerals are significant on a level p>0,05. The energy value of Macedonian trout meat is 435.29 KJ/100gm, i.e. and 498.49 KJ/100gm in the Ohrid trout meat.

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

    Science.gov (United States)

    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...

  19. ARTIFICIAL BREEDING OF NERETVA SOFTMOUTH TROUT (Salmo obtusirostris Oxyrhincus Heckel, 1851

    Directory of Open Access Journals (Sweden)

    Dževad Handžar

    2015-06-01

    Full Text Available The paper presents an artificial breeding of softmouth trout (Salmo obtusirostris oxyrhynchus, which is one of the endemic species of fish Neretva basin and which is on the Red List of the International Union for Conservation of Nature (IUCN as endangered species facing extinction. Production of fry softmouth trout intended for restocking is very complex and complicated process, and in this paper, which is based on long experience in artificial breeding softmouth trout, we want to contribute to the conservation and breeding of native salmonid fish and aquaculture development of BiH. The paper describes the production technology and production phase, diet and food as well as the application of preventive and therapeutic measures in production. Key word - softmouth trout, artificial breeding, preventive and therapeutic measures

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

    Science.gov (United States)

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

    2017-01-01

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

  1. Assessing effects of stocked trout on nongame fish assemblages in southern Appalachian Mountain streams

    Science.gov (United States)

    Weaver, D.; Kwak, Thomas J.

    2013-01-01

    Fisheries managers are faced with the challenge of balancing the management of recreational fisheries with that of conserving native species and preserving ecological integrity. The negative effects that nonnative trout species exert on native trout are well documented and include alteration of competitive interactions, habitat use, and production. However, the effects that nonnative trout may exert on nongame fish assemblages are poorly understood. Our objectives were to quantify the effects of trout stocking on native nongame fish assemblages intensively on one newly stocked river, the North Toe River, North Carolina, and extensively on other southern Appalachian Mountain streams that are annually stocked with trout. In the intensive study, we adopted a before-after, control-impact (BACI) experimental design to detect short-term effects on the nongame fish assemblage and found no significant differences in fish density, species richness, species diversity, or fish microhabitat use associated with trout stocking. We observed differences in fish microhabitat use between years, however, which suggests there is a response to environmental changes, such as the flow regime, which influence available habitat. In the extensive study, we sampled paired stocked and unstocked stream reaches to detect long-term effects from trout stocking; however, we detected no differences in nongame fish density, species richness, species diversity, or population size structure between paired sites. Our results revealed high inherent system variation caused by natural and anthropogenic factors that appear to overwhelm any acute or chronic effect of stocked trout. Furthermore, hatchery-reared trout may be poor competitors in a natural setting and exert a minimal or undetectable impact on native fish assemblages in these streams. These findings provide quantitative results necessary to assist agencies in strategic planning and decision making associated with trout fisheries, stream

  2. Impacts of Northern Pike on stocked Rainbow Trout in Pactola Reservoir, South Dakota

    Science.gov (United States)

    Scheibel, Natalie C.; Dembkowski, Daniel J.; Davis, Jacob L.; Chipps, Steven R.

    2016-01-01

    Establishment of nonnative Northern Pike Esox lucius in Pactola Reservoir, South Dakota, has prompted concern among biologists about the influence of this species on the lake’s intensively managed salmonid fisheries. Ancedotal information suggests that catch rates of Rainbow Trout Oncorhynchus mykiss have declined while mean size and abundance of Northern Pike has increased, although quantitative information on diet and growth of the Northern Pike population is lacking. To address potential interactions between Northern Pike and Rainbow Trout, we assessed size-dependent predation by Northern Pike on Rainbow Trout and determined the relative energetic contribution of stocked Rainbow Trout to Northern Pike growth using bioenergetics modeling. Stable isotopes combined with traditional diet analyses revealed that smaller Northern Pike (Trout contributed less than 10% to their annual energy consumption. In contrast, larger Northern Pike (≥600 mm TL) consumed primarily Rainbow Trout, which accounted for 56% of their annual energy consumption. Combining estimates of Northern Pike predation with production costs of catchable-size Rainbow Trout revealed that annual economic losses ranged from US$15,259 to $24,801 per year. Over its lifespan, an age-10 Northern Pike was estimated to consume ~117 Rainbow Trout worth approximately $340. Thus, Northern Pike predation substantially influences salmonid management initiatives and is likely a primary factor contributing to reduced Rainbow Trout abundance and return to anglers in Pactola Reservoir. Strategies for reducing Northern Pike predation on Rainbow Trout include increasing the size of stocked fish or altering the timing and spatial distribution of stocking events.

  3. Monitoring of Downstream Salmon and Steelhead at Federal Hydroelectric Facilities, 2005-2006 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Martinson, Rick D.; Kovalchuk, Gregory M.; Ballinger, Dean (Pacific States Marine Fisheries Commission, The Dalles, OR)

    2006-04-01

    this year, we successfully held Pacific lamprey ammocetes. The number of fish sampled at Bonneville Dam was also down this year to 260,742, from 444,580 last year. Reasons for the decline are the same as stated above for John Day. Passage timing at Bonneville Dam was quite similar to previous years with one notable exception, sockeye. Sockeye passage was dominated by two large spikes in late May that greatly condensed the passage pattern, with the middle 80% passing Bonneville in just 18 days. Unlike John Day, passage for the rest of the species was well disbursed from late April through early June. Fish condition was good, with reductions in descaling rates for all species except unclipped steelhead and sockeye. Sockeye mortality matched last year's rate but was considerably lower for all other species. Rare species sampled at Bonneville this year included a bull trout and a eulachon.

  4. Organic diets are equally good for rainbow trout fry as conventional diets

    DEFF Research Database (Denmark)

    Madsen, Lone; Ingerslev, Hans Christian; Dalsgaard, Inger

    2014-01-01

    Rainbow trout (Oncorhynchus mykiss) is the dominant fish species in Danish freshwater aquaculture and the annual production is about 30.000 tonnes. Only a minor part of this production is organic, but the proportion of farmed organic rainbow trout is continuously increasing. The aim of the projec...... ingredients are of organic or conventional origin. Furthermore, fish fed organic diets appear to acquire the same health status as fish fed conventional diets....

  5. Oil adjuvant elevates protection of rainbow trout (Oncorhynchus my-kiss) following injection vaccination against Yersinia ruckeri

    DEFF Research Database (Denmark)

    Jaafar, Rzgar M.; Chettri, Jiwan Kumar; Dalsgaard, Inger

    2016-01-01

    Enteric redmouth disease (ERM) caused by the fish pathogen Yersinia ruckeri is a major threat to freshwater production of rainbow trout throughout all life stages. Injection vaccination of rainbow trout against Y. ruckeri infection has been shown to confer better protection compared to the tradit...

  6. Contribution of cathepsins B, L and D to muscle protein profiles correlated with texture in rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Godiksen, Helene; Morzel, M.; Hyldig, Grethe

    2009-01-01

    Post-mortem softening of fish tissue often results in low yield and decreased product quality. In this study, proteolytic profiles of trout stored 5 days oil ice were obtained by SDS-PAGE. The link between protein hand intensities and firmness of trout fillets was examined through a correlation...

  7. Marine effect of introduced salmonids: Prey consumption by exotic steelhead and anadromous brown trout in the Patagonian Continental Shelf

    Science.gov (United States)

    Ciancio, J.; Beauchamp, D.A.; Pascual, M.

    2010-01-01

    On the basis of stable isotope analysis, we estimated the marine diet of the most abundant anadromous salmonid species in Patagonian Atlantic basins. The results were coupled with bioenergetic and population models to estimate the consumption of food by salmonids and was compared with that by seabirds, the most abundant top predators in the area. Amphipods were the main salmonid prey, followed by sprat, silversides, squid, and euphausiids. The total consumption, even assuming large anadromous salmonid populations, represented Limnology and Oceanography, Inc.

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    Neville, Helen M.; Dunham, Jason B.

    2011-01-01

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

  10. Estrogen receptor mRNA in mineralized tissues of rainbow trout: calcium mobilization by estrogen.

    Science.gov (United States)

    Armour, K J; Lehane, D B; Pakdel, F; Valotaire, Y; Graham, R; Russell, R G; Henderson, I W

    1997-07-07

    RT-PCR was undertaken on total RNA extracts from bone and scales of the rainbow trout, Oncorhynchus mykiss. The rainbow trout estrogen receptor (ER)-specific primers used amplified a single product of expected size from each tissue which, using Southern blotting, strongly hybridized with a 32P-labelled rtER probe under stringent conditions. These data provide the first in vivo evidence of ER mRNA in bone and scale tissues of rainbow trout and suggest that the effects of estrogen observed in this study (increased bone mineral and decreased scale mineral contents, respectively) may be mediated directly through ER.

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Shippentower, Gene E. [Oregon State Univ., Corvallis, OR (United States)

    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 received 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 (SrCl2* 6H2O). 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

  15. Post-prandial metabolic alkalosis in the seawater-acclimated trout: the alkaline tide comes in.

    Science.gov (United States)

    Bucking, Carol; Fitzpatrick, John L; Nadella, Sunita R; Wood, Chris M

    2009-07-01

    The consequences of feeding and digestion on acid-base balance and regulation in a marine teleost (seawater-acclimated steelhead trout; Oncorhynchus mykiss) were investigated by tracking changes in blood pH and [HCO3-], as well as alterations in net acid or base excretion to the water following feeding. Additionally the role of the intestine in the regulation of acid-base balance during feeding was investigated with an in vitro gut sac technique. Feeding did not affect plasma glucose or urea concentrations, however, total plasma ammonia rose during feeding, peaking between 3 and 24 h following the ingestion of a meal, three-fold above resting control values (approximately 300 micromol ml(-1)). This increase in plasma ammonia was accompanied by an increase in net ammonia flux to the water (approximately twofold higher in fed fish versus unfed fish). The arterial blood also became alkaline with increases in pH and plasma [HCO3-] between 3 and 12 h following feeding, representing the first measurement of an alkaline tide in a marine teleost. There was no evidence of respiratory compensation for the measured metabolic alkalosis, as Pa CO2 remained unchanged throughout the post-feeding period. However, in contrast to an earlier study on freshwater-acclimated trout, fed fish did not exhibit a compensating increase in net base excretion, but rather took in additional base from the external seawater, amounting to approximately 8490 micromol kg(-1) over 48 h. In vitro experiments suggest that at least a portion of the alkaline tide was eliminated through increased HCO3- secretion coupled to Cl- absorption in the intestinal tract. This did not occur in the intestine of freshwater-acclimated trout. The marked effects of the external salinity (seawater versus freshwater) on different post-feeding patterns of acid-base balance are discussed.

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

    Science.gov (United States)

    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.

  17. NITRO MUSK ADDUCTS OF RAINBOW TROUT ...

    Science.gov (United States)

    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

  18. Bony fish myelin: evidence for common major structural glycoproteins in central and peripheral myelin of trout.

    Science.gov (United States)

    Jeserich, G; Waehneldt, T V

    1986-02-01

    Peripheral nervous system (PNS) myelin from the rainbow trout (Salmo gairdneri) banded at a density of 0.38 M sucrose. The main myelin proteins consisted of (1) two basic proteins, BPa and BPb (11,500 and 13,000 MW, similar to those of trout central nervous system (CNS) myelin proteins BP1 and BP2), and (2) two glycosylated components, IPb (24,400 MW) and IPc (26,200 MW). IPc comigrated with trout CNS myelin protein IP2 in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, whereas trout CNS myelin protein IP1 had a lower molecular weight (23,000). Following two-dimensional separation, however, both IPb and IPc from PNS showed two components; the more acidic component of IPc comigrated with IP2 from CNS. PNS tissue autolysis led to the formation of IPa (20,000 MW), consisting of two components in isoelectric focusing of which again the more acidic one comigrated with the CNS autolysis product IP0. Limited enzymatic digestion of isolated IP proteins from PNS and CNS led to closely similar degradation patterns, being most pronounced in the case of IP2 and IPc. Immunoblotting revealed that all IP components from trout PNS and CNS myelins reacted with antibodies to trout IP1 (CNS) and bovine P0 protein (PNS) whereas antibodies to rat PLP (CNS) were entirely unreactive. All BP components from trout PNS and CNS myelins bound to antibodies against human myelin basic protein. On the basis of these studies trout PNS and CNS myelins contain at least one common IP glycoprotein, whereas other members of the IP myelin protein family appear closely related. In the CNS myelin of trout the IP components appear to replace PLP.(ABSTRACT TRUNCATED AT 250 WORDS)

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

    Science.gov (United States)

    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.

  20. Determine movement patterns and survival rates of Central Valley Chinook salmon, steelhead and their predators using acoustic tags.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project’s objective is to document movement patterns and survival rates of Chinook salmon, steelhead, green sturgeon, and other fish from several sources in...

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

    DEFF Research Database (Denmark)

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

    2000-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Brostrom, Jody K. (US Fish and Wildlife Service, Idaho Fishery Resource Office, Ahsahka, ID)

    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 mm 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 release

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  5. Monitoring of downstream salmon and steelhead at federal hydroelectric facilities, 1991

    International Nuclear Information System (INIS)

    Hawkes, L.A.; Martinson, R.D.; Smith, W.W.

    1992-04-01

    The 1991 smolt monitoring project of the National Marine Fisheries Service provided data on the seaward migration of juvenile salmon and steelhead at John Day, The Dalles and Bonneville Dams. All pertinent fish capture and condition data as well as dam operations and river flow data were provided to Fish Passage Center for use in developing fish passage indices and migration timing, and for water budget and spill management

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

    Energy Technology Data Exchange (ETDEWEB)

    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, 2009 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 two

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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 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.

  9. Protein retention assessment of four levels of poultry by-product substitution of fishmeal in rainbow trout (Oncorhynchus mykiss) diets using stable isotopes of nitrogen (δ15N) as natural tracers.

    Science.gov (United States)

    Badillo, Daniel; Herzka, Sharon Z; Viana, Maria Teresa

    2014-01-01

    This is second part from an experiment where the nitrogen retention of poultry by-product meal (PBM) compared to fishmeal (FM) was evaluated using traditional indices. Here a quantitative method using stable isotope ratios of nitrogen (δ(15)N values) as natural tracers of nitrogen incorporation into fish biomass is assessed. Juvenile rainbow trout (Oncorhynchus mykiss) were fed for 80 days on isotopically distinct diets in which 0, 33, 66 and 100% of FM as main protein source was replaced by PBM. The diets were isonitrogenous, isolipidic and similar in gross energy content. Fish in all treatments reached isotopic equilibrium by the end of the experiment. Two-source isotope mixing models that incorporated the isotopic composition of FM and PBM as well as that of formulated feeds, empirically derived trophic discrimination factors and the isotopic composition of fish that had reached isotopic equilibrium to the diets were used to obtain a quantitative estimate of the retention of each source of nitrogen. Fish fed the diets with 33 and 66% replacement of FM by PBM retained poultry by-product meal roughly in proportion to its level of inclusion in the diets, whereas no differences were detected in the protein efficiency ratio. Coupled with the similar biomass gain of fishes fed the different diets, our results support the inclusion of PBM as replacement for fishmeal in aquaculture feeds. A re-feeding experiment in which all fish were fed a diet of 100% FM for 28 days indicated isotopic turnover occurred very fast, providing further support for the potential of isotopic ratios as tracers of the retention of specific protein sources into fish tissues. Stable isotope analysis is a useful tool for studies that seek to obtain quantitative estimates of the retention of different protein sources.

  10. A physiological toxicokinetic model for dermal absorption of waterborne pyrene by trout

    Energy Technology Data Exchange (ETDEWEB)

    Namdari, R.; Law, F.C.P. [Simon Fraser Univ., Burnaby, British Columbia (Canada)

    1995-12-31

    A physiologically-based toxicokinetic (PB-TK) model was developed to describe the disposition of pyrene in trout following a bolus injection into the dorsal aorta. In the present study, the PB-TK model was adapted for dermal absorption of waterborne pyrene by trout. A skin compartment with transdermal flux described mathematically by the permeability-area-concentration product was added to the PB-TK model to allow prediction of pyrene concentrations in target organs and blood on the basis of exposure concentration at the skin surface. Physiologically relevant parameters e.g., organ volume, blood flow rate, and tissue/blood partitioning coefficient which were derived from the model were similar to those reported in the previous publication. The dermal PB-TK model was validated by exposing the trunk of trout (400--500 g) to stagnant water containing 24 ppm pyrene in a specially designed chamber for 4 hr, 24 hr or 48 hr. The trout were sacrificed at the conclusion of pyrene exposure and the tissues analyzed for unchanged pyrene by HPLC. In separate experiments, trout were implanted with dorsal aorta cannuli before the trunks were exposed to stagnant water containing 24 ppm pyrene in the chamber for 4 hr. At specific time intervals during and after pyrene exposure, blood samples were withdrawn through the cannula and analyzed for pyrene by HPLC. The agreement between simulated and experimentally obtained values shows that this model is an appropriate tool to predict dermal absorption of waterborne pyrene by trout.

  11. A New Single Nucleotide Polymorphism Database for Rainbow Trout Generated Through Whole Genome Resequencing

    Directory of Open Access Journals (Sweden)

    Guangtu Gao

    2018-04-01

    Full Text Available Single-nucleotide polymorphisms (SNPs are highly abundant markers, which are broadly distributed in animal genomes. For rainbow trout (Oncorhynchus mykiss, SNP discovery has been previously done through sequencing of restriction-site associated DNA (RAD libraries, reduced representation libraries (RRL and RNA sequencing. Recently we have performed high coverage whole genome resequencing with 61 unrelated samples, representing a wide range of rainbow trout and steelhead populations, with 49 new samples added to 12 aquaculture samples from AquaGen (Norway that we previously used for SNP discovery. Of the 49 new samples, 11 were double-haploid lines from Washington State University (WSU and 38 represented wild and hatchery populations from a wide range of geographic distribution and with divergent migratory phenotypes. We then mapped the sequences to the new rainbow trout reference genome assembly (GCA_002163495.1 which is based on the Swanson YY doubled haploid line. Variant calling was conducted with FreeBayes and SAMtools mpileup, followed by filtering of SNPs based on quality score, sequence complexity, read depth on the locus, and number of genotyped samples. Results from the two variant calling programs were compared and genotypes of the double haploid samples were used for detecting and filtering putative paralogous sequence variants (PSVs and multi-sequence variants (MSVs. Overall, 30,302,087 SNPs were identified on the rainbow trout genome 29 chromosomes and 1,139,018 on unplaced scaffolds, with 4,042,723 SNPs having high minor allele frequency (MAF > 0.25. The average SNP density on the chromosomes was one SNP per 64 bp, or 15.6 SNPs per 1 kb. Results from the phylogenetic analysis that we conducted indicate that the SNP markers contain enough population-specific polymorphisms for recovering population relationships despite the small sample size used. Intra-Population polymorphism assessment revealed high level of polymorphism and

  12. Description age-3 brood rainbow trout bred in the conditions of the industral fish farm "Sloboda Banyliv"

    Directory of Open Access Journals (Sweden)

    P. Mendryshora

    2017-06-01

    Full Text Available Purpose. To analyze the results of cultivation and give fish-breeding and biological characteristics of age-3 brood rainbow trout grown using industrial technology in the conditions of the trout farm "Sloboda Banyliv." Methodology. Fish cultivation was carried in tank conditions of the trout farm "Sloboda Banyliv". The material for the study were age-3 brood rainbow trout obtained from eggs of the fall-spawning form of rainbow trout. Cultivation was carried out in a 216 m2 tank, stocking density of 255 fish/m2, using standard trout culture methods. Statistical analysis of the material was performed in Microsoft Office Excel (2003. Analysis of the variables was performed in the system of absolute values. The analysis criteria were their mean values mean deviations (M±m, standard error (σ, variability coefficient (Cv. Fish were fed with specialized feed manufactured by “BioMar” (Denmark with a high protein content (more than 40%. Findings. Based on the performed selective-breeding works aimed at creating brood stocks of rainbow trout, it was found that brood fish reared in the industrial conditions of the fish farm “Sloboda Banyliv”, despite instable culture conditions, were characterized by a moderate growth rate and had high values of productive and reproductive features. Mean weight of age-3 rainbow trout females was 1282.5 g, fecundity — 3.48 thousand eggs. Mean weight of produced eggs was 239.17 g, while individual parameters were 70.4 mg for the weight and 4.58 mm for the diameter. Originality. For the first time a study aimed at the formation of brood stocks of rainbow trout with analysis of phenotypic and productive features in the conditions of a fish farm with instable temperature and water regimes has been conducted. Practical value. The results of the performed work will allow selecting and forming a brood stock with high values of productive and reproductive features.

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

    Science.gov (United States)

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

    2016-01-01

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

  14. Evaluation of some physico-chemical properties of restructured trout and hake mince during cold gelation and chilled storage

    DEFF Research Database (Denmark)

    Moreno, H.M.; Javier Borderias, A.; Baron, Caroline

    2010-01-01

    Cold gelation was carried out on trout (Oncorhynchus mykiss) or on hake (Merluccius mertuccius) mince with or without addition of fish oil and using microbial transglutaminase (MTGase). Products were stored at 4 QC for 6 days and lipid oxidation, protein oxidation, texture, water binding capacity......, and colour were followed. Results indicated that MTGase was able to generate gels with good properties for both trout and hake. Gels prepared with trout were oxidised whilst gels prepared with hake were stable toward oxidation even in the presence of 5% fish oil. However, in the presence of oil...

  15. Testing experimental subunit furunculosis vaccines for rainbow trout

    DEFF Research Database (Denmark)

    Marana, Moonika H.; Chettri, Jiwan Kumar; Skov, Jakob

    2016-01-01

    Aeromonas salmonicida subsp. salmonicida (AS) is the etiological agent of typical furunculosis in salmonid fish. The disease causes bacterial septicemia and is a major fish health problem in salmonid aquaculture worldwide, inducing high morbidity and mortality. In this study we vaccinated rainbow...... trout with subunit vaccines containing protein antigens that were selected based on an in silico antigen discovery approach. Thus, the proteome of AS strain A449 was analyzed by an antigen discovery platform and its proteins consequently ranked by their predicted ability to evoke protective immune...... response against AS. Fourteen proteins were prepared in 3 different experimental subunit vaccine combinations and used to vaccinate rainbow trout by intraperitoneal (i.p.) injection. We tested the proteins for their ability to elicit antibody production and protection. Thus, fish were exposed to virulent...

  16. Life+ Trout Project (LIFE12 NAT/IT/0000940 for the recovery and conservation of Mediterranean trout (Salmo trutta complex in the central Apennines (Italy.

    Directory of Open Access Journals (Sweden)

    Vincenzo Caputo Barucchi

    2015-11-01

    At present the genetic and demographic characterization of the trout populations is completed. Table 1 and Figures 1-2 show the results of abundance analysis of the fish assemblages divided by basin. The standing crop’s mean values can be considered in the standard range, according to the small size and the limited productivity that generally characterized the watercourses analyzed, as most of the Apennine rivers. The differences of the mean values among basins were highly statistically significant according to the ANOVA analysis (density: F= 5.24, p=0.001; standing crop: F=12.42, p=0.001. The results of genetic analysis separated clearly native and aliene genomes (K = 2, Fig. 3a and showed the presence of three distinct genetic stocks of native Apennine trout (K = 4, Fig. 3b: i Tevere (green bars, ii Tenna (red and iii Chienti /Potenza/Metauro/Esino (yellow. Populations characterized by very low introgression values will be the source of wild individuals to produce pure juvenile trouts in captivity. Four moderately introgressed populations will be subject to supportive breeding activities. Finally, six stream, where trouts showed almost exclusively an alien genetic make-up will be selected for the eradication activities. The data collected are the indispensable premise for the adoption of the necessary strategies for conservation of the Apennine trout in Central Italy.

  17. Farming of Freshwater Rainbow Trout in Denmark

    DEFF Research Database (Denmark)

    Jokumsen, Alfred; Svendsen, Lars Moeslund

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

  18. A real-time polymerase chain reaction method for the identification of four commercially important salmon and trout species.

    Science.gov (United States)

    Feng, Junli; Wu, Zhigang; Xie, Xiao; Dai, Zhiyuan; Liu, Shasha

    2017-01-01

    A duplex quantitative real-time PCR (qPCR) assay was developed for rapid and accurate identification of four commercially important salmon and trout species (Oncorhynchus keta, Oncorhynchus nerka, Oncorhynchus mykiss, and Salmo salar) commonly used for production process of fish in China. The assays targeting the mitochondrial control region (CR) and 16S rRNA gene were able to simultaneously discriminate four target species and the family Salmonidae from processed as well as fresh fish. The qPCR efficiency of each reaction was calculated according to the standard curve, and the method was validated by amplification DNA extracted from single or artificial mixtures prepared with the reference salmon and trout species. Testing of 11 commercial salmon and trout products by the established qPCR assay demonstrated that it was really a useful and academic technique to identify four commercially important salmon and trout species.

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

    Science.gov (United States)

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

    2017-01-01

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

  20. Hybridization dynamics between Colorado's native cutthroat trout and introduced rainbow trout.

    Science.gov (United States)

    Metcalf, Jessica L; Siegle, Matthew R; Martin, Andrew P

    2008-01-01

    Newly formed hybrid populations provide an opportunity to examine the initial consequences of secondary contact between species and identify genetic patterns that may be important early in the evolution of hybrid inviability. Widespread introductions of rainbow trout (Oncorhynchus mykiss) into watersheds with native cutthroat trout (Oncorhynchus clarkii) have resulted in hybridization. These introductions have contributed to the decline of native cutthroat trout populations. Here, we examine the pattern of hybridization between introduced rainbow trout and 2 populations of cutthroat trout native to Colorado. For this study, we utilized 7 diagnostic, codominant nuclear markers and a diagnostic mitochondrial marker to investigate hybridization in a population of greenback cutthroat trout (Oncorhynchus clarkii stomias) and a population of Colorado River cutthroat trout (Oncorhynchus clarkii pleuriticus). We infer that cutthroat-rainbow trout hybrid swarms have formed in both populations. Although a mixture of hybrid genotypes was present, not all genotype combinations were detected at expected frequencies. We found evidence that mitochondrial DNA introgression in hybrids is asymmetric and more likely from rainbow trout than from cutthroat trout. A difference in spawning time of the 2 species or differences in the fitness between the reciprocal crosses may explain the asymmetry. Additionally, the presence of intraspecific cytonuclear associations found in both populations is concordant with current hypotheses regarding coevolution of mitochondrial and nuclear genomes.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-10-01

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

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

    Science.gov (United States)

    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.

  3. Kootenai River fisheries investigations. Chapter 3: Mainstem habitat use and recruitment estimates of rainbow trout in the Kootenai River, Idaho. Annual report 1996

    International Nuclear Information System (INIS)

    Fredericks, J.; Hendricks, S.

    1997-09-01

    The objective of this study was to determine if recruitment is limiting the population of rainbow trout Oncorhynchus mykiss in the mainstem Kootenai River. The authors used snorkeling and electrofishing techniques to estimate juvenile rainbow trout density and total numbers in Idaho tributaries, and they trapped juvenile outmigrants to identify the age at which juvenile trout migrate from tributaries to the Kootenai River. The authors radio and reward-tagged post-spawn adult rainbow trout captured in Deep Creek to identify river reach and habitat used by those fish spawning and rearing in the Deep Creek drainage. They also conducted redd surveys in the Kootenai River to determine the extent of mainstem spawning. Based on the amount of available habitat and juvenile rainbow trout densities, the Deep Creek drainage was the most important area for juvenile production. Population estimates of age 0, age 1+, and age 2+ rainbow trout indicated moderate to high densities in several streams in the Deep Creek drainage whereas other streams, such as Deep Creek, had very low densities of juvenile trout. The total number of age 0, age 1+, and age 2+ rainbow trout in Deep Creek drainage in 1996 was estimated to be 63,743, 12,095, and 3,095, respectively. Radio telemetry efforts were hindered by the limited range of the transmitters, but movements of a radio-tagged trout and a returned reward tag indicated that at least a portion of the trout utilizing the Deep Creek drainage migrated downriver from the mouth of Deep Creek to the meandering section of river. They found no evidence of mainstem spawning by rainbow trout, but redd counting efforts were hindered by high flows from mid-April through June

  4. Liquid Holding Capacity and Liquid Leakage of Raw Salmon and Trout Fillets

    DEFF Research Database (Denmark)

    Løje, Hanne; Nielsen, Henrik Hauch; Hyldig, Grethe

    2017-01-01

    and liquid holding capacity of salmon and trout are influenced by fat content. Liquid leakage did not depend on fat content whereas the liquid holding capacity was lower for fish with high fat content. Thus the methods provide supplementary rather than equal information. Furthermore the water loss part...... was linear depending on liquid loss. The results indicate that fat is more loosely bound in trout than in salmon. These findings may be of immediate relevance to quality control of high-value fat fish products, to assessment of raw material properties, to an efficient treatment in the production...

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Gary E.; Skalski, J. R.; Carlson, Thomas J.; Ploskey, Gene R.; Weiland, Mark A.; Deng, Zhiqun; Fischer, Eric S.; Hughes, James S.; Khan, Fenton; Kim, Jin A.; Townsend, Richard L.

    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.

  7. A second generation genetic map for rainbow trout (Oncorhynchus mykiss

    Directory of Open Access Journals (Sweden)

    Gahr Scott A

    2008-11-01

    Full Text Available Abstract Background Genetic maps characterizing the inheritance patterns of traits and markers have been developed for a wide range of species and used to study questions in biomedicine, agriculture, ecology and evolutionary biology. The status of rainbow trout genetic maps has progressed significantly over the last decade due to interest in this species in aquaculture and sport fisheries, and as a model research organism for studies related to carcinogenesis, toxicology, comparative immunology, disease ecology, physiology and nutrition. We constructed a second generation genetic map for rainbow trout using microsatellite markers to facilitate the identification of quantitative trait loci for traits affecting aquaculture production efficiency and the extraction of comparative information from the genome sequences of model fish species. Results A genetic map ordering 1124 microsatellite loci spanning a sex-averaged distance of 2927.10 cM (Kosambi and having 2.6 cM resolution was constructed by genotyping 10 parents and 150 offspring from the National Center for Cool and Cold Water Aquaculture (NCCCWA reference family mapping panel. Microsatellite markers, representing pairs of loci resulting from an evolutionarily recent whole genome duplication event, identified 180 duplicated regions within the rainbow trout genome. Microsatellites associated with genes through expressed sequence tags or bacterial artificial chromosomes produced comparative assignments with tetraodon, zebrafish, fugu, and medaka resulting in assignments of homology for 199 loci. Conclusion The second generation NCCCWA genetic map provides an increased microsatellite marker density and quantifies differences in recombination rate between the sexes in outbred populations. It has the potential to integrate with cytogenetic and other physical maps, identifying paralogous regions of the rainbow trout genome arising from the evolutionarily recent genome duplication event, and

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

    OpenAIRE

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

    2013-01-01

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

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

    Science.gov (United States)

    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.

  10. Influence of a trout farm on macrozoobenthos communities of the Trešnjica river, Serbia

    Directory of Open Access Journals (Sweden)

    Živić Ivana

    2009-01-01

    Full Text Available Trout farming poses an increasing threat to quality of the water of clean highland streams. Research of this problem has focused primarily on changes in physico-chemical composition of the water and structure of the river bottom, and less on the effects on living organisms. In the present work, we investigated influence of the farm with the highest trout production in Serbia, the 'Riboteks' Trout Farm on the Trešnjica River, on its macrozoobenthos communities. Our investigations showed that the 'Riboteks' Trout Farm wastewaters caused a clear and statistically significant change of moderate intensity in all measured parameters describing the composition and structure of macrozoobenthos communities. These changes were most pronounced in the part of the watercourse closest to the influx of waste water (locality III but remained statistically significant even 500 m downstream (locality IV and were lost only about 3.5 km away from the influx of the farm's wastewater (locality V. The most pronounced were changes in the participation in total abundance of the Baetidae, Chironomidae, and Plecoptera. Additionally, results of the present work confirmed that the mass of fish on the trout farm is a parameter that adequately defines the strength of its action, above all the intensity of its influence on structure of the macrozoobenthos community.

  11. Dynamics of the Oso-Steelhead landslide from broadband seismic analysis

    Science.gov (United States)

    Hibert, C.; Stark, C. P.; Ekström, G.

    2015-06-01

    We carry out a combined analysis of the short- and long-period seismic signals generated by the devastating Oso-Steelhead landslide that occurred on 22 March 2014. The seismic records show that the Oso-Steelhead landslide was not a single slope failure, but a succession of multiple failures distinguished by two major collapses that occurred approximately 3 min apart. The first generated long-period surface waves that were recorded at several proximal stations. We invert these long-period signals for the forces acting at the source, and obtain estimates of the first failure runout and kinematics, as well as its mass after calibration against the mass-centre displacement estimated from remote-sensing imagery. Short-period analysis of both events suggests that the source dynamics of the second event is more complex than the first. No distinct long-period surface waves were recorded for the second failure, which prevents inversion for its source parameters. However, by comparing the seismic energy of the short-period waves generated by both events we are able to estimate the volume of the second. Our analysis suggests that the volume of the second failure is about 15-30% of the total landslide volume, giving a total volume mobilized by the two events between 7 × 106 and 10 × 106 m3, in agreement with estimates from ground observations and lidar mapping.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    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. The 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.

  13. Identification of Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) by using polymerase chain reaction amplification and restriction analysis of the mitochondrial cytochrome b gene.

    Science.gov (United States)

    Carrera, E; García, T; Céspedes, A; González, I; Sanz, B; Hernández, P E; Martín, R

    1998-04-01

    Restriction site analysis of polymerase chain reaction (PCR) products from a conserved region of the cytochrome b gene has been used for the identification of fresh and smoked samples of Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss). Digestion of the 359-bp PCR product with the endonucleases EcoRV and TaqI yielded specific banding patterns for salmon and trout. This genetic marker can be very useful for detecting fraudulent substitution of the cheaper smoked trout for the more expensive smoked salmon.

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

    Energy Technology Data Exchange (ETDEWEB)

    Skalski, John R.; Townsend, Richard L.; Seaburg, Adam; Johnson, Gary E.; Ploskey, Gene R.; Carlson, Thomas J.

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Skalski, John R.; Townsend, Richard L.; Seaburg, Adam; Johnson, Gary E.; Ploskey, Gene R.; Carlson, Thomas J.

    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.

  16. Toxicokinetics of PFOS in rainbow trout

    Data.gov (United States)

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

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

    Directory of Open Access Journals (Sweden)

    Megan Moore

    Full Text Available 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.

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

    Science.gov (United States)

    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. StreamNet: Report on the status of salmon and steelhead in the Columbia River Basin -- 1995

    International Nuclear Information System (INIS)

    Anderson, D.A.; Christofferson, G.; Beamesderfer, R.; Woodard, B.; Rowe, M.; Hansen, J.

    1996-04-01

    Information on fish populations, fisheries, and fish habitat is crucial to the success of ongoing program to protect, recover, enhance, and manage fish resources in the Columbia River Basin. However, pertinent data are often difficult to locate because it is scattered among many agencies and is often unpublished. The goal of this annual report is to bring many diverse data types and sources into a single comprehensive report on the status of anadromous fish runs in the Columbia River Basin and the environmental conditions that may affect that status. Brief summaries are provided to identify the type and scope of available information. This synopsis is intended to complement other more detailed reports to which readers are referred for comprehensive treatment of specific subjects. This first report focuses mainly on anadromous salmon and steelhead (primarily through 1994) but the authors intend to expand the scope of future issues to include resident species. This is the first of what the authors intend to be an annual report. They welcome constructive suggestions for improvements. This report is a product of the StreamNet (formerly Coordinated Information System and Northwest Environmental Data Base) project which is a part of the Bonneville Power Administration's program to protect, mitigate, and enhance fish and wildlife affected by the development and operation of hydroelectric facilities on the Columbia River and its tributaries. The project is called for in the Fish and Wildlife Program of the Northwest Power Planning Council. The project's objective is to promote exchange and dissemination of information in a standardized electronic format throughout the basin. This project is administered by the Pacific States Marine Fisheries Commission with active participation by tribal, state, and federal fish and wildlife agencies

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

    Science.gov (United States)

    Korsu, Kai; Huusko, Ari; Muotka, Timo

    2009-03-01

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

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

    Science.gov (United States)

    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.

  2. Environmental prevalence and persistence of Listeria monocytogenes in cold-smoked trout processing plants

    Science.gov (United States)

    The presence of Listeria monocytogenes on the surfaces of equipment and workers' hands during different production stages, as well as on fish skin and meat during processing and storage of cold-smoked trout, was investigated. Listeria monocytogenes was recovered from 10 (6.06%) of a total 165 cotto...

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2011-01-01

    Lacustrine-adfluvial bull trout, Salvelinus confluentus, migrate from spawning and rearing streams to lacustrine environments as early as age 0. Within lacustrine environments, cover habitat pro- vides refuge from potential predators and is a resource that is competed for if limiting. Competitive inter- actions between bull trout and other species could result in bull trout being displaced from cover habitat, and bull trout may lack evolutionary adaptations to compete with introduced species, such as lake trout, Salvelinus namaycush. A laboratory experiment was performed to examine habitat use and interactions for cover by juvenile (i.e., 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.

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

    Science.gov (United States)

    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.

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

    DEFF Research Database (Denmark)

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

    2004-01-01

    Radio telemetry was employed to study movements of adult female anadromous brown trout Salmo trutta (sea trout) during upstream spawning migration and following spawning in a stream with tributaries. Sea trout were monitored by manual tracking and by automatic listening stations. The latter...... suggested that initiation of upstream migration was positively correlated with stream discharge. Individual sea trout performed repeated upstream migration 'initiations' (visits) to areas where they were detected by the automatic listening stations. The first and subsequent upstream migration 'initiations...

  8. Limnology of nine small lakes, Matanuska-Susitna Borough, Alaska, and the survival and growth rates of rainbow trout

    Science.gov (United States)

    Woods, P.F.

    1985-01-01

    The survival and growth rates of rainbow trout (Salmo gairdnieri) were concurrently measured with selected limnological characteristics in nine small (surface area Gasterosteus aculeatus) also influenced survival of rainbow trout but their effects were overshadowed by winterkill. Predictive capability was also reduced because of inconsistencies in rankings generated by each of the four limnological variables chosen as indicators of potential biological productivity. A lake ranked low in productivity by one variable was commonly ranked high in productivity by another variable. The survivability of rainbow trout stocked in lakes such as these nine may be a more important indicator of potential biomass production than are indicators of lake fertility. Assessments of a lake 's susceptibility to winterkill and the degree of competition with threespine stickleback are suggested as important topics for additional research. (Author 's abstract)

  9. Sensitivity of Trout to Chronic Acute Exposure to Selenium

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Gissel; Nielsen, M. Gissel

    1978-01-01

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

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

    Science.gov (United States)

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

  11. Movement and mortality of stocked brown trout in a stream

    DEFF Research Database (Denmark)

    Aarestrup, Kim; Jepsen, Niels; Koed, Anders

    2005-01-01

    The movement and mortality of stocked brown trout Salmo trutta were investigated using radio telemetry. Four brown trout left the study area whereas the remaining fish were stationary. After 5 weeks, 13 out of 50 tagged brown trout were still alive in the stream. Surviving fish had a significantly...

  12. Biology and management of threatened and endangered western trouts

    Science.gov (United States)

    R. J. Behnke; Mark Zarn

    1976-01-01

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    Science.gov (United States)

    Johnson, James H.; McKenna, James E.

    2015-01-01

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

  16. Constraints on Energy Intake in Fish: The Link between Diet Composition, Energy Metabolism, and Energy Intake in Rainbow Trout

    Science.gov (United States)

    Saravanan, Subramanian; Schrama, Johan W.; Figueiredo-Silva, A. Claudia; Kaushik, Sadasivam J.; Verreth, Johan A. J.; Geurden, Inge

    2012-01-01

    The hypothesis was tested that fish fed to satiation with iso-energetic diets differing in macronutrient composition will have different digestible energy intakes (DEI) but similar total heat production. Four iso-energetic diets (2×2 factorial design) were formulated having a contrast in i) the ratio of protein to energy (P/E): high (HP/E) vs. low (LP/E) and ii) the type of non-protein energy (NPE) source: fat vs. carbohydrate which were iso-energetically exchanged. Triplicate groups (35 fish/tank) of rainbow trout were hand-fed each diet twice daily to satiation for 6 weeks under non-limiting water oxygen conditions. Feed intake (FI), DEI (kJ kg−0.8 d−1) and growth (g kg−0.8 d−1) of trout were affected by the interaction between P/E ratio and NPE source of the diet (Ptrout by ∼20%. The diet-induced differences in FI and DEI show that trout did not compensate for the dietary differences in digestible energy or digestible protein contents. Further, changes in body fat store and plasma glucose did not seem to exert a homeostatic feedback control on DEI. Independent of the diet composition, heat production of trout did not differ (P>0.05). Our data suggest that the control of DEI in trout might be a function of heat production, which in turn might reflect a physiological limit related with oxidative metabolism. PMID:22496852

  17. Utilization of dietary urea in rainbow trout.

    Science.gov (United States)

    Kaushik, S J; Dabrowski, K R; Dabrowska, H; Olah, E; Luquet, P

    1983-01-01

    Experiments were conducted to examine the potential utilization of dietary urea by rainbow trout. A control diet and two diets supplemented with 1 and 3% of urea were fed to fish. Postprandial levels of urea and ammonia in blood plasma, and postprandial excretion of these metabolites were followed during 24 h. Apparent digestibility of urea in rainbow trout was very high (greater than 98%). Maximum values of urea levels in plasma were reached 6 h (32.3 +/- 10.2 micrograms/ml) after a meal in the control fish and respectively 6 h (83.4 +/- 18.4 micrograms/ml) and 8 h (250.3 +/- 96.1 micrograms/ml) after a meal in trout fed 1 and 3% urea diets. Peaks of urea excretion rates appeared 7-9 h after meal, coinciding with the highest circulating urea concentration. Total daily urea excretion amounted to 5.53, 10.43 and 33.80 mg urea N/100 mg N intake in trout fed the control, 1 and 3% urea diets, respectively. It is concluded that the dietary urea is readily absorbed in the digestive tract of trout but is totally excreted thus leading to no beneficial effect on nitrogen balance. This excretion of urea also takes place passively without any increase in energy demands.

  18. The trout fishery in Shenandoah National Park

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2013-11-25

    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.

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

    Science.gov (United States)

    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

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

    DEFF Research Database (Denmark)

    Fritzner, N.G.; Hansen, Michael Møller; Madsen, S.S.

    2001-01-01

    Based on estimates of genetic differentiation between populations, assignment tests and analysis of isolation by distance, stocked populations of brown trout Salmo trutta of Funen Island, Denmark, had been genetically affected by domesticated trout, whereas the stocking of wild exogenous trout...... into one of the rivers had little or no impact. At the same time, there were clear indications of remaining indigenous gene pools in the Funen populations. The management implications of these findings are discussed and changes in trout release activity are recommended to avoid further mixing of trout gene...

  2. Immunity to VHS virus in rainbow trout

    DEFF Research Database (Denmark)

    Lorenzen, Niels; Olesen, Niels Jørgen; Koch, C.

    1999-01-01

    Viral hemorrhagic septicemia virus (VHSV) is the rhabdovirus that causes most disease problems in farmed rainbow trout in Europe. Survivors of infection are usually immune to reinfection but as with other fish viruses, development of a modern recombinant vaccine has been complicated by the limited...... knowledge of the immune mechanisms and antigens involved in induction of immunity. Neutralizing and protective monoclonal antibodies recognize the envelope glycoprotein (G protein) which is the only viral protein known to be present on the surface of the virus particle. Immunoblotting analyses...... with monoclonal antibodies as well as with sera from immunized trout have indicated that protein conformation plays an important role in neutralization epitopes. The virus neutralizing activity often found in sera from convalescent trout is highly dependent on a poorly defined complementing activity in normal...

  3. Microsomal biotransformation of chlorpyrifos, parathion and fenthion in rainbow trout (Oncorhynchus mykiss) and coho salmon (Oncorhynchus kisutch): mechanistic insights into interspecific differences in toxicity

    Science.gov (United States)

    Lavado, Ramon

    2010-01-01

    Rainbow trout often serve as a surrogate species evaluating xenobiotic toxicity in cold-water species including other salmonids of the same genus, which are listed as threatened or endangered. Biotransformation tends to show species-specific patterns that influence susceptibility to xenobiotic toxicity, particularly organophoshpate insecticides (OPs). To evaluate the contribution of biotransformation in the mechanism of toxicity of three organophosphate (phosphorothionate) insecticides, chlorpyrifos, parathion and fenthion, microsomal bioactivation and detoxification pathways were measured in gills, liver and olfactory tissues in juvenile rainbow trout (Oncorhynchus mykiss) and compared to juvenile coho salmon (Oncorhynchus kisutch). Consistent with species differences in acute toxicity, significantly higher chlorpyrifos bioactivation was found in liver microsomes of rainbow trout (up to 2-fold) when compared with coho salmon. Although bioactivation to the oxon was observed, the catalytic efficiency towards chlorpyrifos dearylation (detoxification) was significantly higher in liver for both species (1.82 and 0.79 for trout and salmon, respectively) when compared to desulfuration (bioactivation). Bioactivation of parathion to paraoxon was significantly higher (up to 2.2-fold) than detoxification to p-nitrophenol in all tissues of both species with rates of conversion in rainbow trout, again significantly higher than coho salmon. Production of fenoxon and fenthion sulfoxides from fenthion was detected only in liver and gills of both species with activities in rainbow trout significantly higher than coho salmon. NADPH-Dependent hydrolysis of fenthion was observed in all tissues, and was the only activity detected in olfactory tissues. These results indicate rainbow trout are more sensitive than coho salmon to the acute toxicity of OP pesticides because trout have higher catalytic rates of oxon formation. Thus, rainbow trout may serve as a conservative surrogate

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

    Energy Technology Data Exchange (ETDEWEB)

    Harnish, Ryan A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Colotelo, Alison H. A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Li, Xinya [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fu, Tao [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ham, Kenneth D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Deng, Zhiqun [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Green, Ethan D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    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 collected 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 to aid

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

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, James S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weiland, Mark A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Woodley, Christa M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ploskey, Gene R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carpenter, Scott M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hennen, Matthew J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fischer, Eric S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Batton, George [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carlson, Thomas J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cushing, Aaron W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Deng, Zhiqun [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Etherington, D. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fu, Tao [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Greiner, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ingraham, John M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kim, Jin A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Li, Xi [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Martinez, Jayson J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mitchell, T. D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rayamajhi, Bishes [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Seaburg, Adam [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Skalski, J. R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Townsend, Richard L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wagner, Katie A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zimmerman, Shon A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    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.

  6. Microsatellite analyses of the trout of northwest Mexico

    Science.gov (United States)

    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.

  7. Integrated Status and Effectiveness Monitoring Program - Entiat River Rotary Screw Traps,Snorkel Surveys, and Steelhead Redd Surveys, 2008.

    Energy Technology Data Exchange (ETDEWEB)

    Nelle, R.D.; Desgroseiller, Tom; Cotter, Michael (U.S. Fish and Wildlife Service)

    2009-02-17

    The USFWS Mid-Columbia River Fishery Resource Office (MCRFRO) operated two rotary screw traps on the Entiat River as part of the Integrated Status and Effectiveness Monitoring Program from March through November of 2008. Along with the smolt traps, juvenile emigrants were also captured at remote locations throughout the Entiat watershed and its major tributary, the Mad River. A total of 16,782 wild salmonids were PIT tagged during the study period. Of this, 3,961(23.6%) were wild Oncorhynchus mykiss, 6,987 (41.6%) were wild spring run O. tshawytscha, and 5,591 (33.3%) were identified as wild O. tshawytscha of unknown run. Rotary screw trap efficiencies averaged 40.3% at the upper (Rkm 11.0) trap and 7.8% for the lower (Rkm 2.0) trap. These efficiencies were pooled for emigrant O. tshawytscha and O. mykiss. The MCRFRO conducted effectiveness monitoring snorkel surveys at 24 sites during the winter period and 30 sites during the summer and fall periods of 2008 as part of the Integrated Status and Effectiveness Monitoring Program in the Entiat River. The 2008 steelhead spawning grounds surveys were conducted weekly in the main Entiat River from rkm 1.1 to 44.2. A total of 222 steelhead redds were identified over the period from February 28 to June 16 2008 with April being the peak spawning month. Approximately 80% of the steelhead redds were located downstream of the rkm 26.

  8. Integrated Status and Effectiveness Monitoring Program - Entiat River Rotary Screw Traps, Snorkel Surveys, and Steelhead Redd Surveys, 2008-2009.

    Energy Technology Data Exchange (ETDEWEB)

    Nelle, R.D.; Desgroseillier, Tom; Cotter, Michael [U.S. Fish and Wildlife Service

    2009-04-14

    The USFWS Mid-Columbia River Fishery Resource Office (MCRFRO) operated two rotary screw traps on the Entiat River as part of the Integrated Status and Effectiveness Monitoring Program from March through November of 2008. Along with the smolt traps, juvenile emigrants were also captured at remote locations throughout the Entiat watershed and its major tributary, the Mad River. A total of 16,782 wild salmonids were PIT tagged during the study period. Of this, 3,961(23.6%) were wild Oncorhynchus mykiss, 6,987 (41.6%) were wild spring run O. tshawytscha, and 5,591 (33.3%) were identified as wild O. tshawytscha of unknown run. Rotary screw trap efficiencies averaged 40.3% at the upper (Rkm 11.0) trap and 7.8% for the lower (Rkm 2.0) trap. These efficiencies were pooled for emigrant O. tshawytscha and O. mykiss. The MCRFRO conducted effectiveness monitoring snorkel surveys at 24 sites during the winter period and 30 sites during the summer and fall periods of 2008 as part of the Integrated Status and Effectiveness Monitoring Program in the Entiat River. The 2008 steelhead spawning grounds surveys were conducted weekly in the main Entiat River from rkm 1.1 to 44.2. A total of 222 steelhead redds were identified over the period from February 28 to June 16 2008 with April being the peak spawning month. Approximately 80% of the steelhead redds were located downstream of the rkm 26.

  9. Marine Model Trout Farms: developments in marine RAS

    DEFF Research Database (Denmark)

    Pedersen, Per Bovbjerg

    2011-01-01

    , nitrogen is removed in a full-scale experimental set-up where sludge from the drum filter is hydrolysed and the VFAs generated used as energy-source for the denitrification process in separate tanks/filters. Final polishing follows in a constructed wetland. For the first 2 years of operation production......Economical and environmentally sustainable production of large salmonids in sea water has in Denmark been called for during some years. Based on the experience gained from the Danish Model Trout Farms in freshwater, a rather similar concept has been developed for farming of larger fish in sea water...... temperature the pumps can be individually turned on/off primarily in relation to oxygen need and consumption in the fish tank. In a 1 year batch production some 20 t of fish will be introduced in April and some 80 t are supposed to be harvested in December. End-of-pipe treatment is a two-step process. First...

  10. Application of heteroduplex analysis for detecting variation within the growth hormone 2 gene in Salmo trutta L. (brown trout).

    Science.gov (United States)

    Gross, R; Nilsson, J

    1995-03-01

    A new method to detect variation at a single copy nuclear gene in brown trout, Salmo trutta L., is provided. The technique entails (i) selective gene amplification by the polymerase chain reaction (PCR), (ii) digestion of amplification products by restriction endonucleases to obtain fragments of suitable size, (iii) hybridization with heterologous DNA followed by denaturation and reannealing to obtain heteroduplex molecules, and (iv) screening for variation in polyacrylamide gels. Variation was studied within a growth hormone 2 gene 1489 bp segment and polymorphism was detected in two HinfI-digested fragments. Formation of different heteroduplex patterns in experimental mixtures of digested amplification products from brown trout and Atlantic salmon, Salmo salar L., allowed us to determine the genotype of the brown trout. Polymorphism was observed in four out of six studied populations.

  11. Erosion of interspecific reproductive barriers resulting from hatchery supplementation of rainbow trout sympatric with cutthroat trout.

    Science.gov (United States)

    Docker, Margaret F; Dale, Angie; Heath, Daniel D

    2003-12-01

    The frequency of hybridization between cutthroat (Onchorhynchus clarki clarki) and rainbow (O. mykiss irideus) trout from coastal habitats in British Columbia, Canada, was examined in seven populations where the two species are sympatric with no history of rainbow trout stocking and compared with areas where native rainbow trout populations have been supplemented with hatchery fish (three populations). Four nuclear markers were used to identify each species and interspecific hybrids and one mitochondrial marker showed the direction of gene exchange between species. The frequency of hybrids was significantly higher (Fisher exact test, P < 0.001) in river systems where hatchery rainbow trout have been introduced (50.6% hybrids) than in populations where the two species naturally co-occur without supplementation (9.9% hybrids).

  12. Comparative analysis of innate immune responses to Streptococcus phocae strains in Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Salazar, Soraya; Oliver, Cristian; Yáñez, Alejandro J; Avendaño-Herrera, Ruben

    2016-04-01

    Streptococcus phocae subsp. salmonis is a Gram-positive bacterium that causes mortality only in Atlantic salmon (Salmo salar) farmed in Chile, even when this species is co-cultured with rainbow trout (Oncorhynchus mykiss). This susceptibility could be determined by innate immune response components and their responses to bacterial infection. This fish pathogen shares subspecies status with Streptococcus phocae subsp. phocae isolated from seals. The present study compared innate immune system mechanisms in Atlantic salmon and rainbow trout when challenged with different S. phocae, including two isolates from Atlantic salmon (LM-08-Sp and LM-13-Sp) and two from seal (ATCC 51973(T) and P23). Streptococcus phocae growth was evaluated in the mucus and serum of both species, with rainbow trout samples evidencing inhibitory effects. Lysozyme activity supported this observation, with significantly higher (p trout serum and mucus as compared to Atlantic salmon. No differences were found in phagocytic capacity between fish species when stimulated with ATCC 51973(T) and P23. Against all S. phocae strains, rainbow trout and Atlantic salmon showed up to two-fold increased bactericidal activity, and rainbow trout demonstrated up to three-fold greater reactive oxygen species production in macrophages. In conclusion, the non-specific humoral and cellular barriers of Atlantic salmon were immunologically insufficient against S. phocae subsp. salmonis, thereby facilitating streptococcosis. Moreover, the more robust response of rainbow trout to S. phocae could not be attributed to any specific component of the innate immune system, but was rather the consequence of a combined response by the evaluated components. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Fish Research Project, Oregon : Evaluation of the Success of Supplementing Imnaha River Steelhead with Hatchery Reared Smolts: Phase One : Completion Report.

    Energy Technology Data Exchange (ETDEWEB)

    Carmichael, Richard W.; Whitesel, Timothy A.; Jonasson, Brian C.

    1995-08-01

    Two streams in the Imnaha River subbasin (Camp Creek and Little Sheep Creek) and eight streams in the Grande Ronde River subbasin (Catherine, Deer, Five Points, Fly, Indian, Lookingglass, Meadow, and Sheep creeks) were selected as study streams to evaluate the success and impacts of steelhead supplementation in northeast Oregon. The habitat of the study streams was inventoried to compare streams and to evaluate whether habitat might influence the performance parameters we will measure in the study. The mean fecundity of hatchery and natural steelhead 1-salts returning to Little Sheep Creek fish facility in 1990 and 1991 ranged from 3,550 to 4,663 eggs/female; the mean fecundity of hatchery and natural steelhead 2-salts ranged from 5,020 to 5,879 eggs/female. Variation in length explained 57% of the variation in fecundity of natural steelhead, but only 41% to 51% of the variation in fecundity of hatchery steelhead. Adult steelhead males had an average spermatocrit of 43.9% at spawning. We were also able to stain sperm cells so that viable cells could be distinguished from dead cells. Large, red disc tags may be the most useful for observing adults on the spawning grounds. The density of wild, juvenile steelhead ranged from 0 fish/l00{sup 2} to 35.1 (age-0) and 14.0 (age-1) fish/l00m{sup 2}. Evidence provided from the National Marine Fisheries Service suggests that hatchery and wild fish within a subbasin are genetically similar. The long-term experimental design is presented as a component of this report.

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

    International Nuclear Information System (INIS)

    Schwabe, Lawrence; Tiley, Mark

    2000-01-01

    The purpose of this study is to document the seasonal distribution of adult/sub-adult bull trout (Salvelinus confluentus) in the Malheur River basin. Due to the decline of bull trout in the Columbia Basin, the United States Fish and Wildlife Service listed bull trout as a threatened species in June 1998. Past land management activities; construction of dams; and fish eradication projects in the North Fork and Middle Fork Malheur River by poisoning have worked in concert to cumulatively impact native species in the Malheur Basin (Bowers et. al. 1993). Survival of the remaining bull trout populations is severely threatened (Buchanan 1997). 1999 Research Objects are: (1) Document the migratory patterns of adult/sub-adult bull trout in the North Fork Malheur River; (2) Determine the seasonal bull trout use of Beulah Reservoir and bull trout entrainment; and (3) Timing and location of bull trout spawning in the North Fork Malheur River basin. The study area includes the Malheur basin from the mouth of the Malheur River located near Ontario, Oregon to the headwaters of the North Fork Malheur River (Map 1). All fish collected and most of the telemetry effort was done on the North Fork Malheur River subbasin (Map 2). Fish collection was conducted on the North Fork Malheur River at the tailwaters of Beulah Reservoir (RK 29), Beulah Reservoir (RK 29-RK 33), and in the North Fork Malheur River at Crane Crossing (RK 69) to the headwaters of the North Fork Malheur. Radio telemetry was done from the mouth of the Malheur River in Ontario, Oregon to the headwaters of the North Fork Malheur. This report will reflect all migration data collected from 3/1/99 to 12/31/99

  15. Estrogenic effect of the phytoestrogen biochanin A in zebrafish, Danio rerio, and brown trout, Salmo trutta.

    Science.gov (United States)

    Holbech, Henrik; Schröder, Kristoffer D; Nielsen, Marie L; Brande-Lavridsen, Nanna; Holbech, Bente Frost; Bjerregaard, Poul

    2013-11-15

    Isoflavones with estrogenic activity produced in Fabaceae plants are known to leach from agricultural areas to freshwater systems, but the effect of waterborne isoflavones in fish has not been thoroughly characterized. Therefore, the estrogenic effect of waterborne biochanin A was investigated in zebrafish (Danio rerio) and juvenile brown trout (Salmo trutta). Exposure of juvenile brown trout to 10 μg biochanin AL(-1) or higher caused marked vitellogenin induction after 9-10 days of exposure and so did exposure to 186 μg biochanin AL(-1) for 6h. Following 8d of exposure, a NOEC for induction of vitellogenin production in male zebrafish was 70 and LOEC 114 μg biochanin AL(-1). Exposure to 209 μg biochanin AL(-1) from hatch to 60 days post hatch (dph) caused a skewing of the sex ratio toward more phenotypic female zebrafish, but did not cause induction of vitellogenin in male and undifferentiated fish. (1) biochanin A elicits estrogenic effects in trout at environmentally realistic concentrations, (2) brown trout plasma vitellogenin concentrations respond to lower biochanin A exposure concentrations than vitellogenin concentrations in zebrafish homogenates and (3) concerning vitellogenin induction, the hypothesis should be tested if short term tests with zebrafish may show a higher sensitivity than partial life cycle tests. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. The role of the geophysical template and environmental regimes in controlling stream-living trout populations

    Science.gov (United States)

    Penaluna, Brooke E.; Railsback, Steve F.; Dunham, Jason B.; Johnson, S.; Bilby, Richard E.; Skaugset, Arne E.

    2015-01-01

    The importance of multiple processes and instream factors to aquatic biota has been explored extensively, but questions remain about how local spatiotemporal variability of aquatic biota is tied to environmental regimes and the geophysical template of streams. We used an individual-based trout model to explore the relative role of the geophysical template versus environmental regimes on biomass of trout (Oncorhynchus clarkii clarkii). We parameterized the model with observed data from each of the four headwater streams (their local geophysical template and environmental regime) and then ran 12 simulations where we replaced environmental regimes (stream temperature, flow, turbidity) of a given stream with values from each neighboring stream while keeping the geophysical template fixed. We also performed single-parameter sensitivity analyses on the model results from each of the four streams. Although our modeled findings show that trout biomass is most responsive to changes in the geophysical template of streams, they also reveal that biomass is restricted by available habitat during seasonal low flow, which is a product of both the stream’s geophysical template and flow regime. Our modeled results suggest that differences in the geophysical template among streams render trout more or less sensitive to environmental change, emphasizing the importance of local fish–habitat relationships in streams.

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

    Science.gov (United States)

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

    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.

  18. Beaver Evidence - Historical Range of Beaver in the State of California, with an emphasis on areas within the range of coho salmon and steelhead trout

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project examines historical, archaeological, and geological evidence to re-evaluate the existing management paradigm that beaver are non-native to most of...

  19. Development of bull trout sampling protocols

    Science.gov (United States)

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

    2001-01-01

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

  20. Bath vaccination of rainbow trout against yersiniosis

    DEFF Research Database (Denmark)

    Raida, Martin Kristian; Buchmann, Kurt

    2007-01-01

    disease (ERM), was investigated at 5, 15 and 25° C. Rainbow trout fry were kept at controlled temperatures for two month before they were immersed in a commercial Yersinia ruckeri O1 bacterin for 10 minutes. Control groups were sham vaccinated using pure water. Fish were challenged with Yersinia ruckeri O...

  1. Molecular characterization of rainbow trout, Oncorhynchus mykiss

    Indian Academy of Sciences (India)

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

  2. Heavy metal content in the meat of common carp (Cyprinuscarpio L.and rainbow trout (Oncorhynchus mykiss W., cultivated under different technologies

    Directory of Open Access Journals (Sweden)

    St. Stoyanova

    2016-03-01

    Full Text Available Abstract. Water pollution from industrial production and developing agriculture is a serious problem in aquaculture. The aim of this study was to determine the content of heavy metals Zn (zink, Pb(lead, Ni (nickel and Cd (cadmium in the muscles of common carp (Cyprinus carpio L. and rainbow trout (Oncorhynchus mykiss W., grown under different technologies. In the current study were investigated common carp (Cyprinus carpio and rainbow trout (Oncorhynchus mykiss, cultivated in net cages, earthen ponds and raceways. The concentration of heavy metals in the muscles of fish was determined by the methods of AAS in the Scientific laboratory of the Faculty of Agriculture. The influence of different production technologies on the bioaccumulation of Zn, Pb, Ni and Cd (in the flesh of common carp and rainbow trout was found. The Ni content in muscles was 31.25% higher in common carp, cultured at earthen ponds, compared with its content in the flesh of the fish raised in net cages. The concentration of Pd and Ni in rainbow trout, raised in raceways was higher than that determinated for rainbow trout cultivated in net cages, by 25.0% and 7.14%, respectively. The concentration of Cd and Zn of these species, grown in raceways were lower by 33.33% and 2.14%, respectively, compared with their concentration in rainbow trout, cultivated in net cages.

  3. Effect of a Peracetic Acid-Based Disinfectant on Growth, Hematology and Histology of Juvenile Rainbow Trout (Oncorhynchus mykiss

    Directory of Open Access Journals (Sweden)

    Ramtin Hushangi

    2018-02-01

    Full Text Available The effects of a peracetic acid-based disinfectant product (Aquastart® were assessed on some hematological parameters, histological aspects and skin bacterial load of rainbow trout, likewise bacterial load of the rearing tank water. A total of 180 healthy rainbow trout weighing 124.65 ± 10 g were divided into two groups, each in three replicates in flow-through tanks. First group was exposed to Aquastart at 8.9 ppm for 30 min and second group was considered as the control. The fish were then reared for 60 days prior to sampling for hematological and histological studies. The lowest bacterial load level in both water columns and trout skin were observed in the treated trout (p < 0.05. Meanwhile, no significant impact on growth performance was recorded between treated and control fish. The immunocompetent cells population size in control fish were significantly lower than treated fish (p < 0.05. Histologically, no evidence of abnormality was seen in the gills, kidney, and liver tissues of treated fish. These results showed that application of Aquastart at 8.9 ppm is safe for use in flow-through tanks farming rainbow trout.

  4. Infectious pancreatic necrosis the trout farmers' dilemma

    Science.gov (United States)

    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

  5. Dietary acidification enhances phosphorus digestibility but decreases H+/K+-ATPase expression in rainbow trout.

    Science.gov (United States)

    Sugiura, Shozo H; Roy, Prabir K; Ferraris, Ronaldo P

    2006-10-01

    Oxynticopeptic cells of fish stomach are thought to secrete less acid than the specialized parietal cells of mammalian stomach. Gastric acidity, however, has not been directly compared between fish and mammals. We therefore fed rainbow trout and rats the same meal, and found that the lowest postprandial pH of trout stomach was 2.7, which was only transiently sustained for 1 h, whereas that of rat stomach was 1.3, which was sustained for 3 h. Postprandial pH of the small intestine was slightly higher in trout (approximately 8.0) than in rats (approximately 7.6), but pH of the large intestine was similar (approximately 8.0). Addition of acids to fish feeds, in an attempt to aid the weak acidity of fish stomach, has been known to improve phosphorus digestibility, but its physiological effect on fish stomach is not known. Exogenous acids did improve phosphorus digestibility but also decreased steady-state mRNA expression of trout H(+)/K(+)-ATPase (ATP4A, the proton pump) as well as Na(+)/bicarbonate cotransporter (NBC), and had no effect on gastrin-like mRNA and somastostatin (SST) mRNA abundance. Gastrin-like mRNA and SST-2 mRNA were equally distributed between corpus and antrum. ATP4A mRNA and NBC mRNA were in the corpus, whereas SST-1 mRNA was in the antrum. Trout gastrin-like EST had modest homology to halibut and pufferfish gastrin, whereas trout ATP4A mRNA had > or = 95% amino acid homology with mammalian, Xenopus and flounder ATP4A. Although ATP4A seems highly conserved among vertebrates, gastric acidity is much less in trout than in rats, explaining the low digestibility of bone phosphorus, abundant in fish diets. Dietary acidification does not reduce acidity enough to markedly improve phosphorus digestibility, perhaps because exogenous acids may inhibit endogenous acid production.

  6. Umatilla Basin Natural Production Monitoring and Evaluation; 1995-1996 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Contor, Craig R.; Kissner, Paul; Volkman, Jed [Confederated Tribes of the Umatilla Indian Reservation, Pendleton, OR (United States). Dept. of Natural Resources

    1997-08-01

    This report summarizes the activities of the Umatilla Basin Natural Production Monitoring and Evaluation Project (UBNPME) from September 30, 1995 to September 29, 1996. This program was funded by Bonneville Power Administration and was managed under the Fisheries Program, Department of Natural Resources, Confederated Tribes of the Umatilla Indian Reservation. The goal was to evaluate the implementation of the Umatilla River Basin fisheries restoration plan with respect to natural production, adult passage, and tribal harvest. An estimated 56.1 river miles (RM) of habitat was inventoried on the lower Umatilla River (RM 0--56.1) from June 4, to August 1, 1996. The majority of the lower River was found to be too polluted and physically altered to provide suitable rearing or migration habitat for salmonids during the summer. High water temperatures, irrigation withdrawals, altered channels, and urban and agricultural pollution all contributed to degrade the lower Umatilla River. Small springs provided cooler waters and created small areas that were suitable for salmonid rearing. The river below the mouth of Mckay Creek (RM 27.2 to 50.6) was also cooler and more suitable to salmonid rearing when water was released from Mckay Dam. Two hundred sixty-three of 1,832 (14.4%) habitat units were electrofished from June 19 to August 29, 1996. The number of natural juvenile salmonids captured between RM 1.5--52.4 follow: (1) 141 juvenile steelhead (including resident rainbow trout; Oncoryhnchus mykiss), (2) 13 mountain whitefish (Prosopium williamsoni, including adults), (3) four chinook salmon (O. tshawytscha), and (4) two coho salmon (O. kisutch). The expanded population estimate for the areas surveyed was 2,445 salmonids. Mean density was 0.147 salmonids/100 square meter. Mean density of fast water habitat types was 4.5 times higher than slow water types (0.358 and 0.079 s/100 m{sup 2}).

  7. Umatilla Basin natural production monitoring and evaluation. Annual report 1995-1996

    International Nuclear Information System (INIS)

    Contor, C.R.; Hoverson, E.; Kissner, P.; Volkman, J.

    1997-08-01

    This report summarizes the activities of the Umatilla Basin Natural Production Monitoring and Evaluation Project (UBNPME) from September 30, 1995 to September 29, 1996. This program was funded by Bonneville Power Administration and was managed under the Fisheries Program, Department of Natural Resources, Confederated Tribes of the Umatilla Indian Reservation. The goal was to evaluate the implementation of the Umatilla River Basin fisheries restoration plan with respect to natural production, adult passage, and tribal harvest. An estimated 56.1 river miles (RM) of habitat was inventoried on the lower Umatilla River (RM 0--56.1) from June 4, to August 1, 1996. The majority of the lower River was found to be too polluted and physically altered to provide suitable rearing or migration habitat for salmonids during the summer. High water temperatures, irrigation withdrawals, altered channels, and urban and agricultural pollution all contributed to degrade the lower Umatilla River. Small springs provided cooler waters and created small areas that were suitable for salmonid rearing. The river below the mouth of Mckay Creek (RM 27.2 to 50.6) was also cooler and more suitable to salmonid rearing when water was released from Mckay Dam. Two hundred sixty-three of 1,832 (14.4%) habitat units were electrofished from June 19 to August 29, 1996. The number of natural juvenile salmonids captured between RM 1.5--52.4 follow: (1) 141 juvenile steelhead (including resident rainbow trout; Oncoryhnchus mykiss), (2) 13 mountain whitefish (Prosopium williamsoni, including adults), (3) four chinook salmon (O. tshawytscha), and (4) two coho salmon (O. kisutch). The expanded population estimate for the areas surveyed was 2,445 salmonids. Mean density was 0.147 salmonids/100 square meter. Mean density of fast water habitat types was 4.5 times higher than slow water types (0.358 and 0.079 s/100 m 2 )

  8. Summer habitat use by Columbia River redband trout in the Kootenai River drainage, Montana

    Science.gov (United States)

    Muhlfeld, Clint C.; Bennett, David H.

    2001-01-01

    The reported decline in the abundance, distribution, and genetic diversity of Columbia River redband trout Oncorhynchus mykiss gairdneri (a rainbow trout subspecies) has prompted fisheries managers to investigate their habitat requirements, identify critical habitat, and develop effective conservation and recovery programs. We analyzed the microhabitat, mesohabitat, and macrohabitat use and distribution of Columbia River redband trout by means of snorkel surveys in two watersheds in the Kootenai River drainage, Montana and Idaho, during the summers of 1997 and 1998. Juvenile (36–125 mm total length, TL) and adult (>=126 mm TL) fish preferred deep microhabitats (>=0.4 m) with low to moderate velocities (thalweg. Conversely, age-0 (<=35 mm) fish selected slow water (<=0.1 m/s) and shallow depths (<=0.2 m) located in lateral areas of the channel. Age-0, juvenile, and adult fish strongly selected pool mesohabitats and avoided riffles; juveniles and adults generally used runs in proportion to their availability. At the macrohabitat scale, density of Columbia River redband trout (35 mm) was positively related to the abundance of pools and negatively related to stream gradient. The pool: riffle ratio, gradient, and stream size combined accounted for 80% of the variation in density among 23 stream reaches in five streams. Our results demonstrate that low-gradient, medium-elevation reaches with an abundance of complex pools are critical areas for the production of Columbia River redband trout. These data will be useful in assessing the impacts of land-use practices on the remaining populations and may assist with habitat restoration or enhancement efforts.

  9. The effect of protein and lipid source in organic feed for (organic) rainbow trout on sensory quality

    DEFF Research Database (Denmark)

    Hyldig, Grethe; Green-Petersen, Ditte; Jacobsen, Charlotte

    2011-01-01

    of vegetable protein. While the lipid sources were fish, linseed, sunflower, rapeseed and grape seed oil. After slaughtering all fish were frozen (-40°C) until the sensory experiment was performed, for which the trout were thawed and stored for 3, 5, 7 and 14 days in ice respectively. The sensory experiment......-life is increased by feeding the fish with vegetable protein compared to fish meal. The conclusion of the experiment therefore was that both dietary vegetable protein and lipid sources can influence on sensory characteristics of trout stored in ice.......The aim of this work was to study which effects protein and lipid source in feed for organic rainbow trout (Oncohynchus mykiss) may have on the sensory quality of the final product after up to 14 days of storage in ice. The protein sources used in the experiment were fishmeal and a mixture...

  10. How does feed with different levels of vegetable origin affect the sensory quality of ice storage Rainbow trout (Oncorhynchus mykiss)?

    DEFF Research Database (Denmark)

    Hyldig, Grethe; Nielsen, Henrik Hauch; Holm, Jørgen

    carnivores, is facing major challenges as a consequence of the limited access in future sustainable resources of wild fish or other sea living organisms from a lower trophic level for feed production. Consequently, alternative feeding regimes are now considered e.g. use of components of vegetable origin...... and methods Feed trials Rainbow trout were farmed in tanks at Biomar A/S, Hirtshals and fed on six different diets covering only marine, only vegetables and mixture of marine and vegetable feeds. Trout for the quality study were slaughtered, vacuum-packed and stored at -80°C until analysis. Sensory Quality...

  11. Radioisotope x-ray fluorescence and neutron activation analyses of the trace element concentrations of the rainbow trout

    International Nuclear Information System (INIS)

    Akyuz, T.; Bassari, A.; Bolcal, C.; Sener, E.; Yildiz, M.; Kucer, R.; Kaplan, Z.; Dogan, G.; Akyuz, S.

    1999-01-01

    The muscles and livers of the ten rainbow trouts (Oncorhynchus mykiss; N, 1752) obtained from Sapanca, Aquaculture Facility of Aquatic Products Faculty, The University of Istanbul (Turkey), have been analysed quantitatively for some minor elements using the radioisotope energy dispersive X-ray fluorescence (EDXRF) and neutron activation analysis (NAA) methods. It was found that samples contain Na, K, Ca, Sc, Cs, Fe, Co, Cu, Zn, Se, Br, Rb, Sr, Au, La and Ce in different amounts. Comparison of the results with those of reference river fish samples indicated that agricultural rainbow trout samples from Sapanca region have higher Fe level. (author)

  12. Lipolysis og different oils using crude enzyme isolate from the intestinal tract of rainbow trout, Oncorhynchus mykiss

    DEFF Research Database (Denmark)

    Göttsche, J.R.; Nielsen, Nina Skall; Nielsen, Henrik Hauch

    2005-01-01

    Crude enzyme isolate was prepared from the intestine of rainbow trout. Positional specificity of the crude enzyme isolate was determined from both 1(3)- and 2-MAG products after i n vitro lipolysis of radioactive-labeled triolein. The ratio of 2- MAG/1(3)-MAG was 2:1, suggesting that the overall...... lipase specificity of the enzyme isolate from rainbow trout tended to be 1,3-specific; however, activity against the sn -2 position also was shown. In vitro lipolysis of four different unlabeled oils was performed with the crude enzyme isolate. The oils were: structured lipid [SL; containing the medium...

  13. Radioisotope X-ray fluorescence and neutron activation analyses of the trace element concentrations of the rainbow trout

    Science.gov (United States)

    Akyuz, T.; Bassari, A.; Bolcal, C.; Sener, E.; Yildiz, M.; Kucer, R.; Kaplan, Z.; Dogan, G.; Akyuz, S.

    1999-01-01

    The muscles and livers of the ten rainbow trouts ( Oncorhynchus mykiss; N, 1752) obtained from Sapanca, Aquaculture Facility of Aquatic Products Faculty, The University of Istanbul (Turkey), have been analysed quantitatively for some minor elements using the radioisotope energy dispersive X-ray fluorescence (EDXRF) and neutron activation analysis (NAA) methods. It was found that samples contain Na, K, Ca, Sc, Cs, Fe, Co, Cu, Zn, Se, Br, Rb, Sr, Au, La and Ce in different amounts. Comparison of the results with those of reference river fish samples indicated that agricultural rainbow trout samples from Sapanca region have higher Fe level.

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

    Science.gov (United States)

    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.

  15. Effects of telemetry transmitter placement on egg retention in naturally spawning, captively reared steelhead

    International Nuclear Information System (INIS)

    Berejikian, Barry A.; Brown, Richard S.; Tatara, Chris P.; Cooke, Steven J.

    2007-01-01

    Maturing female anadromous salmonids receiving surgical intraperitoneally-implanted telemetry transmitters may experience difficulty depositing eggs during natural spawning. We allocated maturing adult steelhead females to three treatments: tags surgically implanted in the body cavity (internal), tags implanted between the skin and muscle tissue (subdermal), and non-tagged, and allowed them to spawn naturally in an experimental channel. Internally tagged females retained significantly more eggs than both the subdermally tagged treatment (P = 0.005) and non-tagged controls (P = 0.001); the subdermal and non-tag controls did not differ significantly (P = 0.934). The internal, subdermal and non-tag treatments retained an average of 49%, 11% and 2% of their eggs, respectively. The onset of sexual activity did not differ significantly among treatments (P = 0.413). Post-spawning mortality was 70% for both internally and subdermally tagged females and 0% for non-tagged females (P <0.01). We suggest that subdermal implantation techniques be considered in future studies during the reproductive period to reduce egg retention caused by internal implantation of transmitters

  16. Effects of telemetry transmitter placement on egg retention in naturally spawning, captively reared steelhead

    Energy Technology Data Exchange (ETDEWEB)

    Berejikian, Barry A.; Brown, Richard S.; Tatara, Chris P.; Cooke, Steven J.

    2007-05-01

    Maturing female anadromous salmonids receiving surgical intraperitoneally-implanted telemetry transmitters may experience difficulty depositing eggs during natural spawning. We allocated maturing adult steelhead females to three treatments: tags surgically implanted in the body cavity (internal), tags implanted between the skin and muscle tissue (subdermal), and non-tagged, and allowed them to spawn naturally in an experimental channel. Internally tagged females retained significantly more eggs than both the subdermally tagged treatment (P = 0.005) and non-tagged controls (P = 0.001); the subdermal and non-tag controls did not differ significantly (P = 0.934). The internal, subdermal and non-tag treatments retained an average of 49%, 11% and 2% of their eggs, respectively. The onset of sexual activity did not differ significantly among treatments (P = 0.413). Post-spawning mortality was 70% for both internally and subdermally tagged females and 0% for non-tagged females (P <0.01). We suggest that subdermal implantation techniques be considered in future studies during the reproductive period to reduce egg retention caused by internal implantation of transmitters.

  17. Polychlorinated biphenyl reduction in lake trout by irradiation and broiling

    International Nuclear Information System (INIS)

    Cichy, R.F.; Zabik, M.E.; Weaver, C.M.

    1979-01-01

    The Great Lakes Environmental contaminants surveys (1974-1975) have concluded that excessive concentrations of polychlorinated biphenyls (PCBs) are present in a specific species of lake trout (Salvelinus namaycush). Over 30 ppM of PCBs have been detected in the edible fillet of this fat trout. The objective of this study was to determine the effect of gamma irradiation combined with broiling on the levels of PCBs in lake trout fillets

  18. Toxicity of potassium cyanide to trout. [Salmo gairdneri

    Energy Technology Data Exchange (ETDEWEB)

    Herbert, D W.M.; Merkens, J C

    1952-01-01

    The toxicity of KCN was tested on 50 rainbow trout using a flow through bioassay system. The system was designed to allow water conditions to remain constant throughout the test rather than change through metabolic activities of the fish. Results show: cyanide causes fish to loose equilibrium; cyanide resistance increases if the trout are allowed to acclimate to test temperatures before cyanides is added; young trout are more resistant to cyanide; and the distribution of trout survival times to cyanide concentration approximates a normal distribution. (14 references, 5 figures, 6 tables.

  19. Evaluation of the behavior and movement patterns of adult coho salmon and steelhead in the North Fork Toutle River, Washington, 2005-2009

    Science.gov (United States)

    Liedtke, Theresa L.; Kock, Tobias J.; Rondorf, Dennis W.

    2013-01-01

    The 1980 eruption of Mount St. Helens severely affected the North Fork Toutle River (hereafter Toutle River), Washington, and threatened anadromous salmon (Oncorhynchus spp.) populations in the basin. The Toutle River was further affected in 1989 when a sediment retention structure (SRS) was constructed to trap sediments in the upper basin. The SRS completely blocked upstream volitional passage, so a fish collection facility (FCF) was constructed to trap adult coho salmon (O. kisutch) and steelhead (O. mykiss) so they could be transported upstream of the SRS. The Washington Department of Fish and Wildlife (WDFW) has operated a trap-and-haul program since 1989 to transport coho salmon and steelhead into tributaries of the Toutle River, upstream of the SRS. Although this program has allowed wild coho salmon and steelhead populations to persist in the Toutle River basin, the trap-andhaul program has faced many challenges that may be limiting the effectiveness of the program. We conducted a multi-year evaluation during 2005–2009 to monitor tagged fish in the upper Toutle River to provide information on the movements and behavior of adult coho salmon and steelhead, and to evaluate the efficacy of the FCF. Radio-tagged coho salmon and steelhead were released: (1) in Toutle River tributaries to evaluate the behavior and movements of fish released as part of the trap-and-haul program; (2) between the FCF and SRS to determine if volitional upstream passage through the SRS spillway was possible; (3) in the sediment plain upstream of the SRS to determine if volitional passage through the sediment plain was possible; and (4) downstream of the FCF to evaluate the efficacy of the structure. We also deployed an acoustic camera in the FCF to monitor fish movements near the entrance to the FCF, and in the fish holding vault where coho salmon and steelhead are trapped. A total of 20 radio-tagged coho salmon and 10 radio-tagged steelhead were released into Alder and Hoffstadt

  20. Relating instrumental texture, determined relating instrumental texture, determined attachments, to sensory analysis of rainbow trout, Oncorhynchus mykiss, fillets

    Science.gov (United States)

    Texture is one of the most important quality attributes of fish fillets, and accurate assessment of variation in this attribute, as affected by storage and handling, is critical in providing consistent quality product. Trout fillets received 4 treatments: 3-d refrigeration (R3), 7-d refrigeration (R...

  1. RATE AND CAPACITY OF HEPATIC MICROSOMAL RING HYDROXYLATION OF PHENOL TO HYDROQUINONE AND CATECHOL IN RAINBOW TROUT (ONCORHYNCHUS MYKISS)

    Science.gov (United States)

    Rainbow trout liver microsomes were used to study the rate of ring-hydroxylation of phenol (PH) by directly measuring the production of hydroquinone (HQ), the primary metabolite, and catechol (CAT), a secondary metabolite. An HPLC method with integrated ultroviolet (UV) and elect...

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

    Science.gov (United States)

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

    2013-01-01

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

  3. Studies on the Utilization of Deboned Trout (Oncorhynchus mykiss) Frames in Fish Snack

    OpenAIRE

    Muralidharan, S.

    1999-01-01

    Snack food development studies were conducted to iii utilize trout (Oncorhynchus mykiss) frames, a by-product of the filleting operation, using extrusion and conventional technology. Twin screw extrusion studies were conducted to study the effect of fish mince, non-fat dry milk, process temperature, and moisture content on the physicochemical properties of the extruded snack food. Response surfaces were plotted to understand the effects of the independent variables on dependent variables such...

  4. Effects of increased discharge on spawning and age-0 recruitment of rainbow trout in the Colorado River at Lees Ferry, Arizona

    Science.gov (United States)

    Avery, Luke A.; Korman, Josh; Persons, William R.

    2015-01-01

    Negative interactions of Rainbow Trout Oncorhynchus mykiss with endangered Humpback Chub Gila cypha pose challenges to the operation of Glen Canyon Dam (GCD) to manage for both species in the Colorado River. Operations to enhance the Rainbow Trout tailwater fishery may lead to an increase in downstream movement of the trout to areas where they are likely to interact with Humpback Chub. We evaluated the effects of dam operations on age-0 Rainbow Trout in the tailwater fishery to inform managers about how GCD operations could benefit a tailwater fishery for Rainbow Trout; although this could affect a Humpback Chub population farther downstream. A near year-long increase in discharge at GCD in 2011 enabled us to evaluate whether high and stable flows led to increased spawning and production of age-0 Rainbow Trout compared with other years. Rainbow Trout spawning was monitored by fitting a model to observed redd counts to estimate the number of redds created over a spawning season. Data collected during electrofishing trips in July–September and November were used to acquire age-0 trout population and mortality rate estimates. We found that high and stable flows in 2011 resulted in 3,062 redds (1.7 times the mean of all survey years) and a population estimate of 686,000 age-0 Rainbow Trout (second highest on record). Despite high initial abundance, mortality remained low through the year (0.0043%/d) resulting in significant recruitment with a record high November population estimate of 214,000 age-0 Rainbow Trout. Recent monitoring indicates this recruitment event was followed by an increase in downstream migration, which may lead to increased interactions with downstream populations of Humpback Chub. Consequently, while our results indicate that manipulating flow at GCD can be used to manage Rainbow Trout spawning and recruitment, fisheries managers should use flow manipulation in moderation to minimize downstream migration in order to reduce negative

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

    Science.gov (United States)

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

    2010-01-01

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

  6. Simulation analysis of within-day flow fluctuation effects on trout below flaming Gorge Dam.

    Energy Technology Data Exchange (ETDEWEB)

    Railsback, S. F.; Hayse, J. W.; LaGory, K. E.; Environmental Science Division; EPRI

    2006-01-01

    In addition to being renewable, hydropower has the advantage of allowing rapid load-following, in that the generation rate can easily be varied within a day to match the demand for power. However, the flow fluctuations that result from load-following can be controversial, in part because they may affect downstream fish populations. At Flaming Gorge Dam, located on the Green River in northeastern Utah, concern has been raised about whether flow fluctuations caused by the dam disrupt feeding at a tailwater trout fishery, as fish move in response to flow changes and as the flow changes alter the amount or timing of the invertebrate drift that trout feed on. Western Area Power Administration (Western), which controls power production on submonthly time scales, has made several operational changes to address concerns about flow fluctuation effects on fisheries. These changes include reducing the number of daily flow peaks from two to one and operating within a restricted range of flows. These changes significantly reduce the value of the power produced at Flaming Gorge Dam and put higher load-following pressure on other power plants. Consequently, Western has great interest in understanding what benefits these restrictions provide to the fishery and whether adjusting the restrictions could provide a better tradeoff between power and non-power concerns. Directly evaluating the effects of flow fluctuations on fish populations is unfortunately difficult. Effects are expected to be relatively small, so tightly controlled experiments with large sample sizes and long study durations would be needed to evaluate them. Such experiments would be extremely expensive and would be subject to the confounding effects of uncontrollable variations in factors such as runoff and weather. Computer simulation using individual-based models (IBMs) is an alternative study approach for ecological problems that are not amenable to analysis using field studies alone. An IBM simulates how a

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

    Science.gov (United States)

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

    2008-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Skalski, J. R.; Townsend, Richard L.; Seaburg, Adam; Weiland, Mark A.; Woodley, Christa M.; Hughes, James S.; Ploskey, Gene R.; Deng, Zhiqun; Carlson, Thomas J.

    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 tailrace 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 two

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

    Energy Technology Data Exchange (ETDEWEB)

    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-native 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

  10. Brook trout passage performance through culverts

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2009-01-01

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

  12. The effects of feed composition on the sensory quality of organic rainbow trout during ice storage

    DEFF Research Database (Denmark)

    Green-Pedersen, Ditte; Hyldig, Grethe; Jacobsen, Charlotte

    fishmeal and a mixture of protein from organic vegetable, while the lipid sources were fish oil and organic oil from linseed, sunflower, rapeseed and grape seed. Sensory analysis was performed after 3, 5, 7 and 14 days of storage in ice. The results showed that both protein and lipid source in the feed can...... after 14 days of storage, indicating that vegetable protein in the feed increases the self-life of organic rainbow trout.......The focus of this work was to study which effects the type of protein and lipid source in the feed for organic Rainbow trout influences had on the sensory quality of final product. Two and four different protein and lipid sources were used in the experiment respectively. The protein sources were...

  13. Cortisol regulates nitric oxide synthase in freshwater and seawater acclimated rainbow trout, Oncorhynchus mykiss

    DEFF Research Database (Denmark)

    Gerber, Lucie; Madsen, Steffen S; Jensen, Frank B

    2017-01-01

    Cortisol and nitric oxide (NO) are regulators of ion transport and metabolic functions in fish. In the gill, they show opposite effects on Na(+)/K(+)-ATPase (NKA) activity: cortisol stimulates NKA activity while NO inhibits NKA activity. We hypothesized that cortisol may impact NO production...... in osmoregulatory tissues by regulating NO synthase (NOS) expression. We evaluated the influence of cortisol treatment on mRNA expression of Nos1 and Nos2 in gill, kidney and middle intestine of both freshwater (FW) and seawater (SW) acclimated rainbow trout and found both tissue- and salinity-dependent effects....... Nos2 expression was down-regulated in the gill by cortisol injection in both FW and SW trout. This was substantiated by incubating gill tissue with cortisol ex vivo. Similarly, cortisol injection significantly down-regulated Nos2 expression in kidney of SW fish but not in FW fish. In the middle...

  14. Effects of adjuvant Montanide™ ISA 763 A VG in rainbow trout injection vaccinated against Yersinia ruckeri

    DEFF Research Database (Denmark)

    Jaafar, Rzgar M; Chettri, Jiwan Kumar; Dalsgaard, Inger

    2015-01-01

    Enteric redmouth disease (ERM) caused by the fish pathogen Yersinia ruckeri is a major threat to freshwater production of rainbow trout (Oncorhynchus mykiss) throughout all life stages. Injection vaccination of rainbow trout against Y. ruckeri infection has been shown to confer better protection...... fish (NonVac), 2) fish injected with a commercial vaccine (AquaVac(®) Relera™) (ComVac), 3) fish injected with an experimental vaccine (ExpVac), 4) fish injected with an experimental vaccine + adjuvant (ExpVacAdj) and 5) fish injected with adjuvant alone (Adj). Injection of the experimental vaccine...... of the adjuvant as the challenge produced 100% mortality in the NonVac group, 60% mortality in both of ComVac and Adj groups and only 13 and 2.5% mortalities in the ExpVac and the ExpVacAdj groups, respectively....

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

    African Journals Online (AJOL)

    The aim of this study was to establish whether waterfalls in the uKhahlamba Drakensberg Park, South Africa, are seasonally important in conserving indigenous Natal cascade frog Hadromophryne natalensis tadpole populations from the threat of predation by alien rainbow trout Oncorhynchus mykiss and brown trout Salmo ...

  16. Demographic and habitat requirements for conservation of bull trout

    Science.gov (United States)

    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...

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

    Science.gov (United States)

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

    DEFF Research Database (Denmark)

    Jacobsen, Lene

    2005-01-01

    This study aimed to evaluate otter predation on stocked trout. Large hatchery-reared trout (16-30 cm) were stocked into two Danish rivers with different fish populations. Otter diet before and after trout stocking was determined by analysing 685 spraints, collected regularly during the 35-day study...... period. Fish composition in the rivers before stocking was assessed by electrofishing. In River Trend, a typical trout river, the proportion of trout in the otter diet increased from 8% before stocking to 33% a few days after stocking. Moreover, trout lengths in the diet changed significantly towards...... the lengths of stocked trout, indicating that newly stocked trout were preferred to wild trout. In River Skals, dominated by cyprinids, there was no change in otter diet after stocking of hatchery trout, i.e., these were ignored by otter. Otter predation should be taken into account together with fish...

  19. Evaluation of a rainbow trout (Oncorhynchus mikyss culture water recirculating system

    Directory of Open Access Journals (Sweden)

    Iván Sánchez O.

    2014-09-01

    Full Text Available Objective. To evaluate a water recirculation system for rainbow trout fish cultures at the recirculating laboratory of the Aquaculture Engineering Production Program of University of Nariño. Materials and Methods. 324 rainbow trout (Oncorhynchus mikyss fries were cultured in 12 plastic tanks with a capacity of 250 L in an aquaculture recirculating system the treatment system of which was made up by a conventional sedimentation tank, a fixed stand upflow biofilter with recycled PVC tube pieces and a natural degassing system; the sedimentation unit effluent was pumped up to a reservoir tank using a 2 HP centrifugal pump after being subject to gravity through the biofilter and to be then distributed to the 12 culture units to which a constant amount of air from a blower was injected. Results. The water treatment system removed 31% of total suspended solids, 9.5% of total ammonia nitrogen, and increased dissolved oxygen to the final effluent in 6.5%. An increase of 305% in biomass was calculated during 75 days, the mortality percentage registered throughout the study period was 4.9%. Conclusions. The water treatment system maintained the physicochemical water quality parameters within the values recommended for the species. The increase in weight and size, food conversion, mortality and biomass production reported normal values for rainbow trout fish culture in recirculating systems.

  20. Estrogenic effects of phytoestrogens in brown trout (Salmo trutta)

    DEFF Research Database (Denmark)

    Nielsen, Louise Marie; Holbech, Henrik; Bjerregaard, Poul

    2010-01-01

    , the potential effect of the waterborne phytoestrogens on endemic fish species is largely unknown. In the present investigation, the estrogenic effect of biochanin A was tested in brown trout through water exposure experiments. Juvenile brown trout of both sexes were exposed to different concentrations...... of biochanin A. In a ten day exposure experiments, NOEC and LOEC for plasma vitellogenin induction in brown trout were found to be 0.8µg biochanin A/L and 1.2µg biochanin A/L, respectively. A six hour pulse experiment resulted in NOEC and LOEC for induction of plasma vitellogenin in brown trout of 48µg...... biochanin A/L and 186µg biochanin A/L, respectively. Investigations of the ability of genistein to induce vitellogenin synthesis in brown trout are ongoing....

  1. Status of Oregon's Bull Trout.

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

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

  2. Variability of kokanee and rainbow trout food habits, distribution, and population dynamics, in an ultraoligotrophic lake with no manipulative management

    Science.gov (United States)

    Buktenica, M.W.; Girdner, S.F.; Larson, G.L.; McIntire, C.D.

    2007-01-01

    Crater Lake is a unique environment to evaluate the ecology of introduced kokanee and rainbow trout because of its otherwise pristine state, low productivity, absence of manipulative management, and lack of lotic systems for fish spawning. Between 1986 and 2004, kokanee displayed a great deal of variation in population demographics with a pattern that reoccurred in about 10 years. We believe that the reoccurring pattern resulted from density dependent growth, and associated changes in reproduction and abundance, driven by prey resource limitation that resulted from low lake productivity exacerbated by prey consumption when kokanee were abundant. Kokanee fed primarily on small-bodied prey from the mid-water column; whereas rainbow trout fed on large-bodied prey from the benthos and lake surface. Cladoceran zooplankton abundance may be regulated by kokanee. And kokanee growth and reproductive success may be influenced by the availability of Daphnia pulicaria, which was absent in zooplankton samples collected annually from 1990 to 1995, and after 1999. Distribution and diel migration of kokanee varied over the duration of the study and appeared to be most closely associated with prey availability, maximization of bioenergetic efficiency, and fish density. Rainbow trout were less abundant than were kokanee and exhibited less variation in population demographics, distribution, and food habits. There is some evidence that the population dynamics of rainbow trout were in-part related to the availability of kokanee as prey. ?? 2007 Springer Science+Business Media B.V.

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

    Energy Technology Data Exchange (ETDEWEB)

    Rayamajhi, Bishes; Ploskey, Gene R.; Woodley, Christa M.; Weiland, Mark A.; Faber, Derek M.; Kim, Jin A.; Colotelo, Alison HA; Deng, Zhiqun; Fu, Tao

    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 tag 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.

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

    Science.gov (United States)

    Ward, David L.; Morton-Starner, Rylan

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Horká Petra

    2017-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Harnish, Ryan A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Colotelo, Alison HA [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Li, Xinya [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ham, Kenneth D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Deng, Zhiqun [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    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 2013 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 and

  7. 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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

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

    2007-01-01

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

  9. Diurnal stream habitat use of juvenile Atlantic salmon, brown trout and rainbow trout in winter

    Science.gov (United States)

    Johnson, J. H.; Douglass, K.A.

    2009-01-01

    The diurnal winter habitat of three species of juvenile salmonids was examined in a tributary of Skaneateles Lake, NY to compare habitat differences among species and to determine if species/age classes were selecting specific habitats. A total of 792 observations were made on the depth, velocity, substrate and cover (amount and type) used by sympatric subyearling Atlantic salmon, subyearling brown trout and subyearling and yearling rainbow trout. Subyearling Atlantic salmon occurred in shallower areas with faster velocities and less cover than the other salmonid groups. Subyearling salmon was also the only group associated with substrate of a size larger than the average size substrate in the study reach during both winters. Subyearling brown trout exhibited a preference for vegetative cover. Compared with available habitat, yearling rainbow trout were the most selective in their habitat use. All salmonid groups were associated with more substrate cover in 2002 under high flow conditions. Differences in the winter habitat use of these salmonid groups have important management implications in terms of both habitat protection and habitat enhancement.

  10. A first generation BAC-based physical map of the rainbow trout genome

    Directory of Open Access Journals (Sweden)

    Thorgaard Gary H

    2009-10-01

    Full Text Available Abstract Background Rainbow trout (Oncorhynchus mykiss are the most-widely cultivated cold freshwater fish in the world and an important model species for many research areas. Coupling great interest in this species as a research model with the need for genetic improvement of aquaculture production efficiency traits justifies the continued development of genomics research resources. Many quantitative trait loci (QTL have been identified for production and life-history traits in rainbow trout. A bacterial artificial chromosome (BAC physical map is needed to facilitate fine mapping of QTL and the selection of positional candidate genes for incorporation in marker-assisted selection (MAS for improving rainbow trout aquaculture production. This resource will also facilitate efforts to obtain and assemble a whole-genome reference sequence for this species. Results The physical map was constructed from DNA fingerprinting of 192,096 BAC clones using the 4-color high-information content fingerprinting (HICF method. The clones were assembled into physical map contigs using the finger-printing contig (FPC program. The map is composed of 4,173 contigs and 9,379 singletons. The total number of unique fingerprinting fragments (consensus bands in contigs is 1,185,157, which corresponds to an estimated physical length of 2.0 Gb. The map assembly was validated by 1 comparison with probe hybridization results and agarose gel fingerprinting contigs; and 2 anchoring large contigs to the microsatellite-based genetic linkage map. Conclusion The production and validation of the first BAC physical map of the rainbow trout genome is described in this paper. We are currently integrating this map with the NCCCWA genetic map using more than 200 microsatellites isolated from BAC end sequences and by identifying BACs that harbor more than 300 previously mapped markers. The availability of an integrated physical and genetic map will enable detailed comparative genome

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

    DEFF Research Database (Denmark)

    Hansen, Michael Møller; Mensberg, Karen-Lise Dons

    2009-01-01

    , but resolution is low if genetic differentiation is weak. Here, we analyse stocked brown trout populations represented by historical (1943-1956) and contemporary (2000s) samples, where genetic differentiation between wild populations and stocked trout is weak (pair-wise F-ST of 0.047 and 0.053). By analysing...... a high number of microsatellite DNA markers (50) and making use of linkage map information, we achieve clear identification of admixed and non-admixed trout. Moreover, despite strong population-level admixture by hatchery strain trout in one of the populations (70.8%), non-admixed individuals...... nevertheless persist (7 out of 53 individuals). These remnants of the indigenous population are characterized by later spawning time than the majority of the admixed individuals. We hypothesize that isolation by time mediated by spawning time differences between wild and hatchery strain trout is a major factor...

  12. Hood River Production Program Monitoring and Evaluation (M&E) - Confederated Tribes of Warm Springs : Annual Report For Fiscal Year, October 2007 – September 2008.

    Energy Technology Data Exchange (ETDEWEB)

    Gerstenberger, Ryan [Confederated Tribes of Warm Springs Reservation

    2009-07-27

    This progress report describes work performed by the Confederated Tribes of Warm Springs (CTWSRO) portion of the Hood River Production Program Monitoring and Evaluation Project (HRPP) during the 2008 fiscal year. A total of 64,736 hatchery winter steelhead, 12,108 hatchery summer steelhead, and 68,426 hatchery spring Chinook salmon smolts were acclimated and released in the Hood River basin during the spring. The HRPP exceeded program goals for a release of and 50,000 winter steelhead but fell short of the steelhead release goals of 30,000 summer steelhead and 75,000 spring Chinook in 2008. Passive Integrated Transponders (PIT) tags were implanted in 6,652 hatchery winter steelhead, and 1,196 hatchery summer steelhead, to compare migratory attributes and survival rates of hatchery fish released into the Hood River. Water temperatures were recorded at six locations within the Hood River subbasin to monitor for compliance with Oregon Department of Environmental Quality water quality standards. A preseason spring Chinook salmon adult run forecast was generated, which predicted an abundant return adequate to meet escapement goal and brood stock needs. As a result the tribal and sport fisheries were opened. A tribal creel was conducted from May 22 to July 18 during which an estimated 172 spring Chinook were harvested. One hundred sixteen Spring Chinook salmon redds were observed and 72 carcasses were inspected on 19.4 miles of spawning grounds throughout the Hood River Basin during 2008. Annual salvage operations were completed in two irrigation canals resulting in the liberation of 1,641 fish back to the Hood River.

  13. Bull trout in the Boundary System: managing connectivity and the feasibility of a reintroduction in the lower Pend Oreille River, northeastern Washington

    Science.gov (United States)

    Dunham, Jason B.; Taylor, Eric B.; Allendorf, Fred W.

    2014-01-01

    Many of the World’s rivers are influenced by large dams (>15 m high) most of which have fragmented formerly continuous habitats, and significantly altered fish passage, natural flow, temperature, and sediment fluxes (Nilsson and others, 2005; Arthington, 2012; Liermann and others, 2012). In the Pacific Northwest, dams on major rivers have been a major focus for fishery managers, primarily in regard to passage of anadromous salmonids (principally Pacific salmon and steelhead trout [Oncorhynchus mykiss], for example, Ferguson and others, 2011), but more recently other species, such as Pacific lamprey (Entosphenus tridentatus) and resident (non-anadromous) salmonids, are receiving more attention (Neraas and Spruell, 2001; Moser and others, 2002; Muhlfeld and others, 2012). In the case of resident salmonids, fish can adopt a wide range of migratory behaviors that often bring them into mainstem rivers where they can come into direct contact with large dams. When this occurs, some of the most important direct effects of dams on salmonids include barriers to upstream and downstream movement and mortality associated with entrainment within the dam or spill over dams. Biologically, these direct impacts can lead to (1) disruption of natural historical (pre-dam) genetic and demographic connectivity among local populations, (2) loss of access to historically used migratory destinations, (3) loss of individuals to the population through mortality associated with entrainment.

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

    DEFF Research Database (Denmark)

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

    1993-01-01

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

  15. Effect of vitamin C on innate immune responses of rainbow trout (Oncorhynchus mykiss) leukocytes.

    Science.gov (United States)

    Leal, Esther; Zarza, Carlos; Tafalla, Carolina

    2017-08-01

    Vitamin C, also known as ascorbic acid, is an essential micronutrient that influences a wide variety of physiological processes, including immunological functions. Although the positive effects of vitamin C supplementation on the immunological status of fish has been established in different species, the bases for these positive effects are still unknown. Hence, the aim of our study was to evaluate the in vitro effect of vitamin C on several innate immune functions of rainbow trout (Oncorhynchus mykiss) leukocyte populations. For this, we assessed the effects exerted on the established rainbow trout monocyte-macrophage cell line RTS11, and compared them to those observed in trout head kidney leukocytes. Our results demonstrate that vitamin C increases the production of reactive oxygen species and the percentage of phagocytic cells in both cell populations. On the other hand, vitamin C had no effect on the surface MHC II levels and only in the case of RTS11 cells increased the capacity of these cells to migrate towards the CK9 chemokine. Finally, vitamin C also increased the transcription of several pro-inflammatory and antimicrobial genes elicited by Escherichia coli, with some differences depending on the cell population studied. Our results contribute to further understand how vitamin C supplementation regulates the fish immune system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Stocking strategy for the rehabilitation of a regulated brown trout (Salmo trutta L.) river

    International Nuclear Information System (INIS)

    Aass, P.

    1993-01-01

    Regulation of the catchment area of the Norwegian river Gudbrandsdalslaagen began in 1919. The lowermost power station on the main river was completed in 1964 and is situated about 10 km above the large Norwegian lake, Mjoesa. The lake is the foraging area of the Hunderstrain of brown trout, the fastest growing of all Norwegian trout. The running of the power plant has led to a severe reduction in water flows below the dam, and the most important spawning and nursery areas of the Hunder strain has been affected. The natural smolt production has been permanently reduced. The rehabilitation programme has included the construction of a fish ladder through the dam and a fixed minimum flow. A hatchery was built and a stocking programme using the local strain was implemented. The effect of stocking has been the easiest of the relief measures to evaluate. Hatchery reared fish constitute a growing share of the spawning population. During the last three years their share has been close to 60%. Reared fish constitute 30-40% of the trout caught in Lake Mjoesa. The average and best returns of tagged groups have been 25 and 50%, respectively, but return rates are highly dependent on release length and time and place of stocking. (Author)

  17. Disposition of naphthalene and its metabolites in the brain of rainbow trout (Salmo gairdneri)

    International Nuclear Information System (INIS)

    Collier, T.K.; Krahn, M.M.; Malins, D.C.

    1980-01-01

    Rainbow trout (Salmo gairdneri) were exposed to orally administered [ 3 H]naphthalene. Another group received naphthyl glucuronic acid and naphthyl sulfate via iv injection. Brain, liver, and blood were assayed for the parent compound and/or total metabolites. Individual naphthalene derivatives were determined by high-performance liquid chromatography (hplc) using either radiometric or on-line fluorimetric detection systems. Naphthalene concentrations in brain (8.2 pmol/mg dry wt at 16 hr after feeding) approximated those found at the same time in liver (7.4 pmol/mg dry wt). A nonconjugated naphthalene derivative, 1,2-dihydro-1,2-dihydroxynaphthalene, also accumulated in brain (0.041 pmol/mg dry wt after 16 hr), although to a lesser degree than in liver (0.10 pmol/mg dry wt after 16 hr). Conjugated naphthalene derivatives, 1-naphthyl sulfate and 1-naphthyl glucuronic acid, although present in liver and blood, were largely excluded from the brain. Low naphthalene hydroxylase activity (<2.0 pmol product formed/mg protein/min) indicated that the trout brain has a minimal ability to oxidize aromatic hydrocarbons. These findings suggest that the brain of adult trout is substantially different from other tissues (e.g., liver and blood) with respect to the disposition of naphthalene and its metabolites

  18. StreamNet; Northwest Aquatic Resource Information Network - Status of Salmon and Steelhead in the Columbia River Basin, 1995 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Duane A.; Beamesderfer, Raymond C. [Oregon Dept. of Fish and Wildlife, Enterprise, OR (United States); Woodard, Bob [Washington Dept. of Fish and Wildlife, Olympia, WA (United States)

    1996-04-01

    Information on fish populations, fisheries, and fish habitat is crucial to the success of ongoing program to protect, recover, enhance, and manage fish resources in the Columbia River Basin. However, pertinent data are often difficult to locate because it is scattered among many agencies and is often unpublished. The goal of this annual report is to bring many diverse data types and sources into a single comprehensive report on the status of anadromous fish runs in the Columbia River Basin and the environmental conditions that may affect that status. Brief summaries are provided to identify the type and scope of available information. This synopsis is intended to complement other more detailed reports to which readers are referred for comprehensive treatment of specific subjects. This first report focuses mainly on anadromous salmon and steelhead (primarily through 1994) but the authors intend to expand the scope of future issues to include resident species. This is the first of what the authors intend to be an annual report. They welcome constructive suggestions for improvements. This report is a product of the StreamNet (formerly Coordinated Information System and Northwest Environmental Data Base) project which is a part of the Bonneville Power Administration`s program to protect, mitigate, and enhance fish and wildlife affected by the development and operation of hydroelectric facilities on the Columbia River and its tributaries. The project is called for in the Fish and Wildlife Program of the Northwest Power Planning Council. The project`s objective is to promote exchange and dissemination of information in a standardized electronic format throughout the basin. This project is administered by the Pacific States Marine Fisheries Commission with active participation by tribal, state, and federal fish and wildlife agencies.

  19. Stable isotope tracing of trout hatchery carbon to sediments and foodwebs of limestone spring creeks

    International Nuclear Information System (INIS)

    Hurd, Todd M.; Jesic, Slaven; Jerin, Jessica L.; Fuller, Nathan W.; Miller, David

    2008-01-01

    Limestone springs support productive ecosystems and fisheries, yet aquaculture may modify or impair these ecosystems. We determined trout hatchery organic contribution to spring creek sediments and foodwebs with natural abundance stable isotope methods. Hatchery feed, waste, and trout were significantly enriched in δ 13 C relative to autotrophs and wild fish. Spring creek sediments were enriched in δ 13 C toward the hatchery endmember relative to reference streams without hatcheries and relative to a larger larger-order, spring-influenced stream. Contribution of hatchery C to spring creek sediments was greatest during March and associated with greatest sediment %C. Contribution of hatchery C to pollution-tolerant isopod diet was 39-51% in a stream receiving limestone spring water via hatchery effluent. Isopods of one spring creek also relied on hatchery-derived C within one month of hatchery closure. Four years later, less pollution pollution-tolerant amphipods dominated and consumed non-vascular over vascular autotrophs (86%). Isopods of a second spring creek with an active hatchery did not appear to be using hatchery matter directly, but were enriched in δ 34 S relative to a spring creek tributary with no hatchery influence. Isopods in both of these streams were relatively enriched in δ 15 N, indicating general nutrient enrichment from surrounding agricultural land use. The contribution of hatchery vs. wild fish in diet of herons and egrets was traced with δ 13 C of guano. These birds were strongly dependent on stocked trout in a spring creek with a recently closed state trout hatchery, and also near another large, state-run hatchery. Heron dependence on hatchery fish in the spring creek decreased with time since hatchery closure. Use of stable isotope natural abundance techniques in karst spring creeks can reveal stream impairment due to aquaculture, specific C sources to bio-indicating consumers, losses of farmed fish to predation, and potential exposure

  20. A Computational Model of the Rainbow Trout Hypothalamus-Pituitary-Ovary-Liver Axis.

    Directory of Open Access Journals (Sweden)

    Kendall Gillies

    2016-04-01

    Full Text Available Reproduction in fishes and other vertebrates represents the timely coordination of many endocrine factors that culminate in the production of mature, viable gametes. In recent years there has been rapid growth in understanding fish reproductive biology, which has been motivated in part by recognition of the potential effects that climate change, habitat destruction and contaminant exposure can have on natural and cultured fish populations. New approaches to understanding the impacts of these stressors are being developed that require a systems biology approach with more biologically accurate and detailed mathematical models. We have developed a multi-scale mathematical model of the female rainbow trout hypothalamus-pituitary-ovary-liver axis to use as a tool to help understand the functioning of the system and for extrapolation of laboratory findings of stressor impacts on specific components of the axis. The model describes the essential endocrine components of the female rainbow trout reproductive axis. The model also describes the stage specific growth of maturing oocytes within the ovary and permits the presence of sub-populations of oocytes at different stages of development. Model formulation and parametrization was largely based on previously published in vivo and in vitro data in rainbow trout and new data on the synthesis of gonadotropins in the pituitary. Model predictions were validated against several previously published data sets for annual changes in gonadotropins and estradiol in rainbow trout. Estimates of select model parameters can be obtained from in vitro assays using either quantitative (direct estimation of rate constants or qualitative (relative change from control values approaches. This is an important aspect of mathematical models as in vitro, cell-based assays are expected to provide the bulk of experimental data for future risk assessments and will require quantitative physiological models to extrapolate across

  1. Prebiotic Supplementation Has Only Minimal Effects on Growth Efficiency, Intestinal Health and Disease Resistance of Westslope Cutthroat Trout Oncorhynchus clarkii lewisi Fed 30% Soybean Meal

    Directory of Open Access Journals (Sweden)

    Wendy M. Sealey

    2015-08-01

    Full Text Available Prebiotics have successfully been used to prevent infectious diseases in aquaculture and there is an increasing amount of literature that suggests that these products can also improve alternative protein utilization and digestion. Therefore, the objective of this study was to examine whether prebiotic supplementation increased the growth efficiency, intestinal health and disease resistance of cutthroat trout fed a high level of dietary soybean meal. To achieve this objective, juvenile Westslope cutthroat trout (Oncorhynchus clarkii lewisi were fed a practical type formulation with 0 or 30% dietary soybean meal with or without the commercial prebiotic (Grobiotic-A prior to experimental exposure to Flavobacterium psychrophilum. Juvenile Westslope cutthroat trout (initial weight 7.8 g/fish ± standard deviation of 0.5 g were stocked at 30 fish/tank in 75 L tanks with six replicate tanks per diet and fed their respective diets for 20 weeks. Final weights of Westslope cutthroat trout were affected by neither dietary soybean meal inclusion level (P=0.9582 nor prebiotic inclusion (P=0.9348 and no interaction was observed (P=0.1242. Feed conversion ratios were similarly not affected by soybean meal level (P=0.4895, prebiotic inclusion (P=0.3258 or their interaction (P=0.1478. Histological examination of the distal intestine of Westslope cutthroat trout demonstrated increases in inflammation due to both increased soybean meal inclusion level (P=0.0038 and prebiotic inclusion (P=0.0327 without significant interaction (P=0.3370. Feeding dietary soybean meal level at 30% increased mortality of F.psychrophilum cohabitation challenged Westslope cutthroat trout (P=0.0345 while prebiotic inclusion tended to decrease mortality (P=0.0671. These results indicate that subclinical alterations in intestinal inflammation levels due to high dietary inclusion levels of soybean meal could predispose Westslope cutthroat trout to F.psychrophilum infection.

  2. Immune response, stress resistance and bacterial challenge in juvenile rainbow trouts Oncorhynchus mykiss fed diets containing chitosan-oligosaccharides

    Directory of Open Access Journals (Sweden)

    Lin LUO, Xuefeng CAI, Chuan HE, Min XUE, Xiufeng WU , Haining CAO

    2009-12-01

    Full Text Available Effects of dietary supplementation of chitosan-oligosaccharides (COS on the growth performance, immune response, stress resistance, and disease resistance of juvenile rainbow trout Oncorhynchus mykiss were studied. Four experimental diets containing 0, 20, 40, or 60 mg/kg COS (COS0, COS20, COS40, and COS60, respectively were fed to juvenile rainbow trout (initial weight = 5.2 ± 0.3 g for 8 weeks. By the end of the feeding trial, representative groups of fish from each dietary treatment were challenged with stressor (30 sec air exposure and pathogen exposure (intraperitoneal injection with Aeromonas hydrophila. Results showed that supplementation of COS in diets did not affect production performance and body composition of rainbow trout. However, fish fed the COS40 diet demonstrated improved phagocytic activities, respiratory burst activities and decreased serum cortisol level. Additionally, survival following A. hydrophila challenge was significant higher among fish fed the COS-supplemented feeds, although there was no difference based on the level of supplementation. The present study suggests that COS can be used as an immuno-stimulant in rainbow trout feeds [Current Zoology 55 (6: 416– 422, 2009].

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  5. Growth of brown trout in acid and alkaline waters

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, R N

    1961-01-01

    Studies have been performed to determine the factors affecting the growth and maturity of brown trout in lochs in the Highlands of Scotland. Evidence has been found which supports the view that the growth rate depends more on the relation between the trout population and the food supply than on any direct influence of the chemical composition of the water. Details are given of the growth rate of trout in nine lochs with a wide range of alkalinities where spawning facilities are either very good or poor or non-existent.

  6. Vertebral column deformities in farmed rainbow trout ( Oncorhynchus mykiss )

    DEFF Research Database (Denmark)

    Madsen, Lone; Dalsgaard, Inger

    1999-01-01

    Farmed rainbow trout (Oncorhynchus mykiss) were fed diets with either different levels of vitamin C, or diets enriched with glucan or chitin, from feeding start and 6 months onwards. At an average weight of 100 g, the trout were X-rayed to determine the deformity level. The investigations showed...... of deformities (4.8%). In all groups examined, the deformities were spread over the whole vertebral column. The deformities in the group fed the low vitamin C diet were more severe than those found in the other groups. An outbreak of the disease rainbow trout fry syndrome (RTFS) caused by the bacterium...

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

    Science.gov (United States)

    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.

  8. Oxidative changes during ice storage of rainbow trout (Oncorhynchus mykiss) fed different ratios of marine and vegetable feed ingredients

    DEFF Research Database (Denmark)

    Timm Heinrich, Maike; Eymard, Sylvie; Baron, Caroline P.

    2013-01-01

    Recently fish meal and oil have increasingly been replaced with proteins and oils from vegetable sources in the diets of farmed salmonids, but the consequences for the oxidative stability of the resulting fish products have not been investigated. The aim of the present study was to evaluate...... the influence of feeding regime on composition of rainbow trout fillets, as well as on lipid and protein oxidation during storage on ice. Rainbow trout were fed six different diets, which differed in their levels of marine oil and proteins vs. vegetable oil and protein. Fish fillets were characterised...... significantly influenced fatty acid composition. Replacement of fish oil with vegetable oil reduced formation of primary oxidation products, but the effect on secondary oxidation products differed between different types of volatiles. The differences in protein and amino acid composition were not significant...

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

    Science.gov (United States)

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

    2013-01-01

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

  10. Bull trout life history, genetics, habitat needs, and limiting factors in Central and Northeast Oregon. Annual report 1996

    International Nuclear Information System (INIS)

    Bellerud, B.L.; Gunkel, S.; Hemmingsen, A.R.; Buchanan, D.V.; Howell, P.J.

    1997-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

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

  12. Spawning Behaviour and the Softmouth Trout Dilemma

    Directory of Open Access Journals (Sweden)

    Esteve Manu

    2014-07-01

    Full Text Available Morphological, ecological and molecular data sets do not completely agree on the phylogenetic placement of the softmouth trout, Salmo (Salmothymus obtusirostris (Heckel. Molecules posit that softmouths are closely related to brown trout, Salmo trutta L. while some morphological, ecological and life history traits place them in the most basal position of the Salmoninae subfamily between grayling (Thymallus and lenok (Brachymystax. Here we add an additional source of data, behavioural characters based on the first reported observations of softmouth spawning. During spawning softmouth females present three important behaviours not found in the other Salmo members: they continually abandon their nests, rarely staying on them for periods over nine minutes; they expel different batches of eggs at the same nest at intervals of several minutes; and they do not cover their eggs immediately after spawning. These three behaviours are intriguing for two reasons: 1 they are possible homologous to behaviours found in grayling females; 2 when coupled to the nest digging behaviour-widespread in all the salmonines, including softmouths, they seem to be mal-adaptive.

  13. Across the great divide: genetic forensics reveals misidentification of endangered cutthroat trout populations.

    Science.gov (United States)

    Metcalf, Jessica L; Pritchard, Victoria L; Silvestri, Sarah M; Jenkins, Jazzmin B; Wood, John S; Cowley, David E; Evans, R Paul; Shiozawa, Dennis K; Martin, Andrew P

    2007-11-01

    Accurate assessment of species identity is fundamental for conservation biology. Using molecular markers from the mitochondrial and nuclear genomes, we discovered that many putatively native populations of greenback cutthroat trout (Oncorhynchus clarkii stomias) comprised another subspecies of cutthroat trout, Colorado River cutthroat trout (Oncorhynchus clarkii pleuriticus). The error can be explained by the introduction of Colorado River cutthroat trout throughout the native range of greenback cutthroat trout in the late 19th and early 20th centuries by fish stocking activities. Our results suggest greenback cutthroat trout within its native range is at a higher risk of extinction than ever before despite conservation activities spanning more than two decades.

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

    Energy Technology Data Exchange (ETDEWEB)

    Weiland, Mark A.; Ploskey, Gene R.; Hughes, James S.; Woodley, Christa M.; Deng, Zhiqun; Carlson, Thomas J.; Skalski, J. R.; Townsend, Richard L.

    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 Fish 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.

  15. Exposure-related effects of Zequanox on juvenile lake sturgeon (Acipenser fulvescens) and lake trout (Salvelinus namaycush)

    Science.gov (United States)

    Luoma, James A.; Severson, Todd J.; Wise, Jeremy K.; Barbour, Matthew

    2018-01-01

    The environmental fate, persistence, and non-target animal impacts of traditional molluscicides for zebra, Dreissena polymorpha, and quagga, D. bugensis, mussel control led to the development of the biomolluscicide Zequanox. Although previous research has demonstrated the specificity of Zequanox, one study indicated sensitivity of salmonids and lake sturgeon, Acipenser fulvescens, following non-label compliant exposures to Zequanox. This study was conducted to evaluate sublethal and lethal impacts of Zequanox exposure on juvenile lake sturgeon and lake trout, Salvelinus namaycush, following applications that were conducted in a manner consistent with the Zequanox product label. Fish were exposed to 50 or 100 mg/L of Zequanox as active ingredient for 8 h and then held for 33 d to evaluate latent impacts. No acute mortality was observed in either species; however, significant latent mortality (P < 0.01, df = 9; 46.2%) was observed in lake trout that were exposed to the highest dose of Zequanox. Statistically significant (P < 0.03, df = 9), but biologically minimal differences were observed in the weight (range 20.17 to 21.49 g) of surviving lake sturgeon at the termination of the 33 d post-exposure observation period. Statistically significant (P < 0.05, df = 9) and biologically considerable differences were observed in the weight (range 6.19 to 9.55 g) of surviving lake trout at the termination of the 33 d post-exposure observation period. Histologic evaluation of lake trout gastrointestinal tracts suggests that the mode of action in lake trout is different from the mode of action that induces zebra and quagga mussel mortality. Further research could determine the sensitivity of other salmonid species to Zequanox and determine if native fish will avoid Zequanox treated water.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Data.gov (United States)

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

  19. ERM booster vaccination of Rainbow trout using diluted bacterin

    DEFF Research Database (Denmark)

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

    2016-01-01

    under laboratory conditions extend the protection period. The present field study investigated the applicability of the method under practical farming conditions (freshwater earth ponds supplied by stream water). Primary immersion vaccination of trout (3–4 g) for 30 s in Y. ruckeri bacterin (diluted 1......Enteric Red Mouth Disease ERM caused by Yersinia ruckeri infection is associated with morbidity and mortality in salmonid farming but immersion vaccination of fry may confer some protection for a number of months. Revaccination of rainbow trout, even by use of diluted ERM immersion vaccine, can......:10) in April 2015 was followed 3 months later (July 2015) by 1 h bathing of rainbow trout in bacterin (diluted 1:650 or 1:1700) in order to evaluate if this time saving vaccination methodology can improve immunity and protection. Trout were subjected in farms to natural Y. ruckeri exposure in June and July...

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

    Data.gov (United States)

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

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

    Data.gov (United States)

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

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

    Data.gov (United States)

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

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

    Data.gov (United States)

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

  4. Muscle wound healing in rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Schmidt, J G; Andersen, E W; Ersbøll, B K; Nielsen, M E

    2016-01-01

    We followed the progression of healing of deep excisional biopsy punch wounds over the course of 365 days in rainbow trout (Oncorhynchus mykiss) by monitoring visual wound healing and gene expression in the healing muscle at regular intervals (1, 3, 7, 14, 38 and 100 days post-wounding). In addition, we performed muscle texture analysis one year after wound infliction. The selected genes have all previously been investigated in relation to vertebrate wound healing, but only few specifically in fish. The selected genes were interleukin (IL)-1β, IL-6, transforming growth factor (TGF)-β1 and -β3, matrix metalloproteinase (MMP) -9 and -13, inducible nitric oxide synthase (iNOS), fibronectin (FN), tenascin-C (TN-C), prolyl 4-hydroxylase α1-chain (P4Hα1), lysyl oxidase (LOX), collagen type I α1-chain (ColIα1), CD41 and CD163. Wound healing progressed slowly in the presented study, which is at least partially due to the low temperature of about 8.5 °C during the first 100 days. The inflammation phase lasted more than 14 days, and the genes relating to production and remodeling of new extracellular matrix (ECM) exhibited a delayed but prolonged upregulation starting 1-2 weeks post-wounding and lasting until at least 100 days post-wounding. The gene expression patterns and histology reveal limited capacity for muscle regeneration in rainbow trout, and muscle texture analyses one year after wound infliction confirm that wounds heal with fibrosis. At 100 dpw epidermis had fully regenerated, and dermis partially regenerated. Scales had not regenerated even after one year. CD163 is a marker of "wound healing"-type M2c macrophages in mammals. M2 macrophage markers are as yet poorly described in fish. The pattern of CD163 expression in the present study is consistent with the expected timing of presence of M2c macrophages in the wound. CD163 may thus potentially prove a valuable marker of M2 macrophages - or a subset hereof - in fish. We subjected a group of fish to

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

    Science.gov (United States)

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

    2015-01-01

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

  6. Effects of cooking methods on electrophoretic patterns of rainbow trout

    Directory of Open Access Journals (Sweden)

    Yasemen Yanar

    2011-07-01

    Full Text Available The aim of this study was to determine the effects of different cooking methods on the electrophoretic patterns of rainbow trout (Oncorhynchus mykiss fillets using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. Raw rainbow trout were deep-fried, microwaved, grilled, and baked and then monitored for changes in the electrophoretic pattern. All cooking methods resulted in significant moisture loss when compared to the raw sample (P

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

    Science.gov (United States)

    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).

  8. Overwintering of sea trout (Salmo trutta) in freshwater

    DEFF Research Database (Denmark)

    Thomsen, Dennis; Koed, Anders; Nielsen, Christian

    2007-01-01

    Brown trout (Salmo trutta) show large phenotypic plasticity. Juveniles may reside in their native freshwater habitat until maturation or migrate into the ocean as 1- to 3-year-old smolts. Sea-going fish (sea trout) reside at sea for 2-3 years until migrating back to their native stream for reprod......Brown trout (Salmo trutta) show large phenotypic plasticity. Juveniles may reside in their native freshwater habitat until maturation or migrate into the ocean as 1- to 3-year-old smolts. Sea-going fish (sea trout) reside at sea for 2-3 years until migrating back to their native stream...... for reproduction. However, immature fish may leave the ocean during their first or second winter at sea and overwinter in freshwater. The question is why does this occur? We tested the hypothesis that hypo-osmoregulatory capacity is compromised by low temperature in two coastal sea trout populations, one...... representing high salinity and the other, low salinity. Immature sea-run trout were caught in lower parts of two rivers during winter and acclimated to laboratory conditions. Subgroups were challenged with high salinity or low water temperature or both, and their osmoregulatory performance was investigated...

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

    Science.gov (United States)

    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.

  10. Conservation of native Pacific trout diversity in western North America

    Science.gov (United States)

    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.

  11. Cadmium-mediated disruption of cortisol biosynthesis involves suppression of corticosteroidogenic genes in rainbow trout

    International Nuclear Information System (INIS)

    Sandhu, Navdeep; Vijayan, Mathilakath M.

    2011-01-01

    Cadmium is widely distributed in the aquatic environment and is toxic to fish even at sublethal concentrations. This metal is an endocrine disruptor, and one well established role in teleosts is the suppression of adrenocorticotrophic hormone (ACTH)-stimulated cortisol biosynthesis by the interrenal tissue. However the mechanism(s) leading to this steroid suppression is poorly understood. We tested the hypothesis that cadmium targets genes encoding proteins critical for corticosteroid biosynthesis, including melanocortin 2 receptor (MC2R), steroidogenic acute regulatory protein (StAR) and cytochrome P450 side chain cleavage enzyme (P450scc), in rainbow trout (Oncorhynchus mykiss). To test this, head kidney slices (containing the interrenal tissues) were incubated in vitro with cadmium chloride (0, 10, 100 and 1000 nM) for 4 h either in the presence or absence of ACTH (0.5 IU/mL). In the unstimulated head kidney slices, cadmium exposure did not affect basal cortisol secretion and the mRNA levels of MC2R and P450scc, while StAR gene expression was significantly reduced. Cadmium exposure significantly suppressed ACTH-stimulated cortisol production in a dose-related fashion. This cadmium-mediated suppression in corticosteroidogenesis corresponded with a significant reduction in MC2R, StAR and P450scc mRNA levels in trout head kidney slices. The inhibition of ACTH-stimulated cortisol production and suppression of genes involved in corticosteroidogenesis by cadmium were completely abolished in the presence of 8-Bromo-cAMP (a cAMP analog). Overall, cadmium disrupts the expression of genes critical for corticosteroid biosynthesis in rainbow trout head kidney slices. However, the rescue of cortisol production as well as StAR and P450scc gene expressions by cAMP analog suggests that cadmium impact occurs upstream of cAMP production. We propose that MC2R signaling, the primary step in ACTH-induced cortocosteroidogenesis, is a key target for cadmium-mediated disruption of

  12. Cadmium-mediated disruption of cortisol biosynthesis involves suppression of corticosteroidogenic genes in rainbow trout

    Energy Technology Data Exchange (ETDEWEB)

    Sandhu, Navdeep [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada); Vijayan, Mathilakath M., E-mail: mvijayan@uwaterloo.ca [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada)

    2011-05-15

    Cadmium is widely distributed in the aquatic environment and is toxic to fish even at sublethal concentrations. This metal is an endocrine disruptor, and one well established role in teleosts is the suppression of adrenocorticotrophic hormone (ACTH)-stimulated cortisol biosynthesis by the interrenal tissue. However the mechanism(s) leading to this steroid suppression is poorly understood. We tested the hypothesis that cadmium targets genes encoding proteins critical for corticosteroid biosynthesis, including melanocortin 2 receptor (MC2R), steroidogenic acute regulatory protein (StAR) and cytochrome P450 side chain cleavage enzyme (P450scc), in rainbow trout (Oncorhynchus mykiss). To test this, head kidney slices (containing the interrenal tissues) were incubated in vitro with cadmium chloride (0, 10, 100 and 1000 nM) for 4 h either in the presence or absence of ACTH (0.5 IU/mL). In the unstimulated head kidney slices, cadmium exposure did not affect basal cortisol secretion and the mRNA levels of MC2R and P450scc, while StAR gene expression was significantly reduced. Cadmium exposure significantly suppressed ACTH-stimulated cortisol production in a dose-related fashion. This cadmium-mediated suppression in corticosteroidogenesis corresponded with a significant reduction in MC2R, StAR and P450scc mRNA levels in trout head kidney slices. The inhibition of ACTH-stimulated cortisol production and suppression of genes involved in corticosteroidogenesis by cadmium were completely abolished in the presence of 8-Bromo-cAMP (a cAMP analog). Overall, cadmium disrupts the expression of genes critical for corticosteroid biosynthesis in rainbow trout head kidney slices. However, the rescue of cortisol production as well as StAR and P450scc gene expressions by cAMP analog suggests that cadmium impact occurs upstream of cAMP production. We propose that MC2R signaling, the primary step in ACTH-induced cortocosteroidogenesis, is a key target for cadmium-mediated disruption of

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

    Science.gov (United States)

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

    2017-01-01

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

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

    OpenAIRE

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

    2013-01-01

    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. bryosalm...

  15. Yersiniosis outbreak in rainbow trout at fish farm in Oromia Regional ...

    African Journals Online (AJOL)

    Ethiopia's physical environment and availability of agricultural residues ... Trout Fish Farmers Private Limited Company has established a commercial trout fish ... different organs were closely observed in situ for the presence of visible macro-.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Jeffrey A Falke

    Full Text Available 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.

  18. Intracellular diffusion restrictions in isolated cardiomyocytes from rainbow trout

    Directory of Open Access Journals (Sweden)

    Birkedal Rikke

    2009-12-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  20. Brook trout movement within a high-elevation watershed: Consequences for watershed restoration

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    Budy, Phaedra; Hafen, Konrad

    2015-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  3. The global impact of alien trout species — a review; with reference ...

    African Journals Online (AJOL)

    Brown trout, Salmo trutta, and rainbow trout, Oncorhynchus mykiss, were first introduced into South African waters as angling species in the later part of the nineteenth century, when environmental impact studies were neither considered nor undertaken. Trout have since been introduced mainly into the cooler upper ...

  4. Global climate change and fragmentation of native brook trout distribution in the southern Appalachian Mountains

    Science.gov (United States)

    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...

  5. Nonnative trout impact an alpine-nesting bird by altering aquatic-insect subsidies.

    Science.gov (United States)

    Epanchin, Peter N; Knapp, Roland A; Lawler, Sharon P

    2010-08-01

    Adjacent food webs may be linked by cross-boundary subsidies: more-productive donor systems can subsidize consumers in less-productive neighboring recipient systems. Introduced species are known to have direct effects on organisms within invaded communities. However, few studies have addressed the indirect effects of nonnative species in donor systems on organisms in recipient systems. We studied the direct role of introduced trout in altering a lake-derived resource subsidy and their indirect effects in altering a passerine bird's response to that subsidy. We compared the abundance of aquatic insects and foraging Gray-crowned Rosy-Finches (Leucosticte tephrocotis dawsoni, "Rosy-Finch") at fish-containing vs. fishless lakes in the Sierra Nevada Mountains of California (USA). Introduced trout outcompeted Rosy-Finches for emerging aquatic insects (i.e., mayflies). Fish-containing lakes had 98% fewer mayflies than did fishless lakes. In lakes without fish, Rosy-Finches showed an aggregative response to emerging aquatic insects with 5.9 times more Rosy-Finches at fishless lakes than at fish-containing lakes. Therefore, the introduction of nonnative fish into the donor system reduced both the magnitude of the resource subsidy and the strength of cross-boundary trophic interactions. Importantly, the timing of the subsidy occurs when Rosy-Finches feed their young. If Rosy-Finches rely on aquatic-insect subsidies to fledge their young, reductions in the subsidy by introduced trout may have decreased Rosy-Finch abundances from historic levels. We recommend that terrestrial recipients of aquatic subsidies be included in conservation and restoration plans for ecosystems with alpine lakes.

  6. Coping with an exogenous glucose overload: glucose kinetics of rainbow trout during graded swimming.

    Science.gov (United States)

    Choi, Kevin; Weber, Jean-Michel

    2016-03-15

    This study examines how chronically hyperglycemic rainbow trout modulate glucose kinetics in response to graded exercise up to critical swimming speed (Ucrit), with or without exogenous glucose supply. Our goals were 1) to quantify the rates of hepatic glucose production (Ra glucose) and disposal (Rd glucose) during graded swimming, 2) to determine how exogenous glucose affects the changes in glucose fluxes caused by exercise, and 3) to establish whether exogenous glucose modifies Ucrit or the cost of transport. Results show that graded swimming causes no change in Ra and Rd glucose at speeds below 2.5 body lengths per second (BL/s), but that glucose fluxes may be stimulated at the highest speeds. Excellent glucoregulation is also achieved at all exercise intensities. When exogenous glucose is supplied during exercise, trout suppress hepatic production from 16.4 ± 1.6 to 4.1 ± 1.7 μmol·kg(-1)·min(-1) and boost glucose disposal to 40.1 ± 13 μmol·kg(-1)·min(-1). These responses limit the effects of exogenous glucose to a 2.5-fold increase in glycemia, whereas fish showing no modulation of fluxes would reach dangerous levels of 114 mM of blood glucose. Exogenous glucose reduces metabolic rate by 16% and, therefore, causes total cost of transport to decrease accordingly. High glucose availability does not improve Ucrit because the fish are unable to take advantage of this extra fuel during maximal exercise and rely on tissue glycogen instead. In conclusion, trout have a remarkable ability to adjust glucose fluxes that allows them to cope with the cumulative stresses of a glucose overload and graded exercise. Copyright © 2016 the American Physiological Society.

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

    Science.gov (United States)

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

    2015-01-01

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

  8. RISK ASSESSMENT OF SURFACE WATERS ASSOCIATED WITH WATER CIRCULATION TECHNOLOGIES ON TROUT FARMS

    Directory of Open Access Journals (Sweden)

    Marcin Sidoruk

    2014-07-01

    Full Text Available Dynamic development of aquaculture has led to an increasing impact on the status of surface waters. Fish production generates wastes that, at high concentrations, may present a serious risk to the aquatic environment. Studies on the assessment of the impact of water management technologies in trout production on the quality of surface waters were conducted in 2011. Six farms were selected for the studies and were divided into two groups based on water management solutions (n = 3: farms with a flow through system (FTS and farms with a recirculation aquaculture system (RAS. On all farms, water measurement points were set and they depicted the quality of inflow water, the quality of water in ponds and the quality of outflow water. The studies did not demonstrate any impact of applied technology on electrolyte conductivity or calcium and magnesium concentrations in outflow water from a trout operation. In addition, it was found that the use of water for production purposes resulted in a slight increase in phosphorus and total nitrogen concentrations in waste waters.

  9. Passage Distribution and Federal Columbia River Power System Survival for Steelhead Kelts Tagged Above and at Lower Granite Dam, Year 2

    Energy Technology Data Exchange (ETDEWEB)

    Colotelo, Alison HA; Harnish, Ryan A.; Jones, Bryan W.; Hanson, Amanda C.; Trott, Donna M.; Greiner, Michael J.; McMichael, Geoffrey A.; Ham, Kenneth D.; Deng, Zhiqun; Brown, Richard S.; Weiland, Mark A.; Li, X.; Fu, Tao

    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 necessary 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 juvenile

  10. Passage Distribution and Federal Columbia River Power System Survival for Steelhead Kelts Tagged Above and at Lower Granite Dam, Year 2

    Energy Technology Data Exchange (ETDEWEB)

    Colotelo, Alison H.A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Harnish, Ryan A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jones, Bryan W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hanson, Amanda C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Trott, Donna M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Greiner, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mcmichael, Geoffrey A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ham, Kenneth D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Deng, Zhiqun [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Brown, Richard S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weiland, Mark A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Li, Xinya [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fu, Tao [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    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 necessary 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 juvenile

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

    Directory of Open Access Journals (Sweden)

    Jean-Claude Le Mével

    2013-07-01

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

  12. Evaluation of an Unsuccessful Brook Trout Electrofishing Removal Project in a Small Rocky Mountain Stream.

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Kevin A.; Lamansky, Jr., James A.; Schill, Daniel J.

    2006-01-26

    In the western United States, exotic brook trout Salvelinus fontinalis frequently have a deleterious effect on native salmonids, and biologists often attempt to remove brook trout from streams by means of electrofishing. Although the success of such projects typically is low, few studies have assessed the underlying mechanisms of failure, especially in terms of compensatory responses. A multiagency watershed advisory group (WAG) conducted a 3-year removal project to reduce brook trout and enhance native salmonids in 7.8 km of a southwestern Idaho stream. We evaluated the costs and success of their project in suppressing brook trout and looked for brook trout compensatory responses, such as decreased natural mortality, increased growth, increased fecundity at length, and earlier maturation. The total number of brook trout removed was 1,401 in 1998, 1,241 in 1999, and 890 in 2000; removal constituted an estimated 88% of the total number of brook trout in the stream in 1999 and 79% in 2000. Although abundance of age-1 and older brook trout declined slightly during and after the removals, abundance of age-0 brook trout increased 789% in the entire stream 2 years after the removals ceased. Total annual survival rate for age-2 and older brook trout did not decrease during the removals, and the removals failed to produce an increase in the abundance of native redband trout Oncorhynchus mykiss gairdneri. Lack of a meaningful decline and unchanged total mortality for older brook trout during the removals suggest that a compensatory response occurred in the brook trout population via reduced natural mortality, which offset the removal of large numbers of brook trout. Although we applaud WAG personnel for their goal of enhancing native salmonids by suppressing brook trout via electrofishing removal, we conclude that their efforts were unsuccessful and suggest that similar future projects elsewhere over such large stream lengths would be costly, quixotic enterprises.

  13. Stream pH as an abiotic gradient influencing distributions of trout in Pennsylvania streams

    Science.gov (United States)

    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

  14. Constraints on energy intake in fish: the link between diet composition, energy metabolism, and energy intake in rainbow trout.

    Directory of Open Access Journals (Sweden)

    Subramanian Saravanan

    Full Text Available The hypothesis was tested that fish fed to satiation with iso-energetic diets differing in macronutrient composition will have different digestible energy intakes (DEI but similar total heat production. Four iso-energetic diets (2 × 2 factorial design were formulated having a contrast in i the ratio of protein to energy (P/E: high (H(P/E vs. low (L(P/E and ii the type of non-protein energy (NPE source: fat vs. carbohydrate which were iso-energetically exchanged. Triplicate groups (35 fish/tank of rainbow trout were hand-fed each diet twice daily to satiation for 6 weeks under non-limiting water oxygen conditions. Feed intake (FI, DEI (kJ kg(-0.8 d(-1 and growth (g kg(-0.8 d(-1 of trout were affected by the interaction between P/E ratio and NPE source of the diet (P0.05. Our data suggest that the control of DEI in trout might be a function of heat production, which in turn might reflect a physiological limit related with oxidative metabolism.

  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.

    Energy Technology Data Exchange (ETDEWEB)

    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 30 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. Effects of treated sewage effluent on immune function in rainbow trout (Oncorhynchus mykiss)

    Energy Technology Data Exchange (ETDEWEB)

    Hoeger, Birgit [Environmental Toxicology, University of Konstanz, P.O. Box X918, D-78457 Constance (Germany); Heuvel, Michael R. van den [Forest Research, Private Bag 3020, Sala St., Rotorua (New Zealand); Hitzfeld, Bettina C. [Swiss Agency for the Environment, Forests and Landscape (SAEFL), Substances, Soil, Biotechnology Division, Section Substances, 3003 Bern (Switzerland); Dietrich, Daniel R. [Environmental Toxicology, University of Konstanz, P.O. Box X918, D-78457 Constance (Germany)]. E-mail: daniel.dietrich@uni-konstanz.de

    2004-12-20

    In this study, the immune reactions of rainbow trout (Oncorhynchus mykiss) were examined, after exposure to 10, 30 and 70% of tertiary-treated municipal sewage effluent for 27 days. Exposures were conducted concurrently with and without an immune challenge using intraperitoneal injections of inactivated Aeromonas salmonicida salmonicida. Due to the time required to prepare and analyse samples, fish sampling was conducted over two consecutive days. There was no trout mortality for any of the experimental treatments. The exposure to effluent increased in vitro lymphocyte proliferation, decreased circulating lymphocytes and increased degrading erythrocytes in peripheral blood samples. Circulating lymphocytes were only decreased in the sham-injected, but not in the A. salmonicida-injected group. In addition to effluent effects, circulating lymphocytes and lymphocyte proliferation were decreased on day 2 of sampling as compared to day 1. Concentration-dependent degradation of erythrocytes was only observed on day 2 of sampling. Capture and removal of trout on day 1 of sampling presumably caused low-level stress that affected some results on day 2. Oxidative burst, phagocytosis, lysozyme, leucocyte populations other than lymphocytes and A. salmonicida-specific IgM production were not affected by exposure to effluent, and of these parameters, only oxidative burst and total leucocytes showed sampling day effects. From these results it can be observed, that with the exception of oxidative burst, those variables affected by effluent exposure were also significantly changed by the low-level sampling stress imposed by staggered sampling. Elevated liver mixed-function oxygenase activity as measured by 7-ethoxyresorufin-O-deethylase activity, and increased bile polycyclic aromatic hydrocarbon (PAH) metabolites were observed in response to sewage effluent exposure. As both PAHs and stress are known immune suppressors, it is difficult to conclude whether or not changes in immune

  17. Effects of chronic high stocking density on liver proteome of rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Naderi, Mahdi; Keyvanshokooh, Saeed; Salati, Amir Parviz; Ghaedi, Alireza

    2017-10-01

    The main aim of the present study was to assess the effects of chronic high stocking density on liver proteome of rainbow trout. Rainbow trout juveniles (42.6 ± 2.3 g average body weight) were randomly distributed into six tanks at two stocking densities (low stocking density (LD) = 20 kg m -3 and high stocking density (HD) = 80 kg m -3 ). Both treatments were performed in triplicate tanks for a period of 60 days. High stocking density caused a reduction in the growth performance compared with LD fish. Lysozyme activity increased with stocking density, while serum complement activity presented the opposite pattern. Serum cortisol and total protein levels did not show significant differences (P > 0.05) between experimental groups. The fish reared at high stocking density showed significantly lower osmolality and globulin values but higher albumin level. The HD group had significantly higher activities of catalase, glutathione peroxidase and superoxide dismutase, and malondialdehyde content in the liver when compared to the LD group. Comparative proteomics was used to determine the proteomic responses in livers of rainbow trout reared at high stocking density for 60 days. Out of nine protein spots showing altered abundance (>1.5-folds, P < 0.05), eight spots were successfully identified. Two proteins including apolipoprotein A-I-2 precursor and mitochondrial stress-70 protein were found to increase in HD group. The spots found to decrease in the HD group were identified as follows: 2-peptidylprolyl isomerase A, two isoforms of glyceraldehydes-3-phosphate dehydrogenase, an unnamed protein product similar to fructose-bisphosphate aldolase, 78 kDa glucose-regulated protein, and serum albumin 1 protein.

  18. Effects of treated sewage effluent on immune function in rainbow trout (Oncorhynchus mykiss)

    International Nuclear Information System (INIS)

    Hoeger, Birgit; Heuvel, Michael R. van den; Hitzfeld, Bettina C.; Dietrich, Daniel R.

    2004-01-01

    In this study, the immune reactions of rainbow trout (Oncorhynchus mykiss) were examined, after exposure to 10, 30 and 70% of tertiary-treated municipal sewage effluent for 27 days. Exposures were conducted concurrently with and without an immune challenge using intraperitoneal injections of inactivated Aeromonas salmonicida salmonicida. Due to the time required to prepare and analyse samples, fish sampling was conducted over two consecutive days. There was no trout mortality for any of the experimental treatments. The exposure to effluent increased in vitro lymphocyte proliferation, decreased circulating lymphocytes and increased degrading erythrocytes in peripheral blood samples. Circulating lymphocytes were only decreased in the sham-injected, but not in the A. salmonicida-injected group. In addition to effluent effects, circulating lymphocytes and lymphocyte proliferation were decreased on day 2 of sampling as compared to day 1. Concentration-dependent degradation of erythrocytes was only observed on day 2 of sampling. Capture and removal of trout on day 1 of sampling presumably caused low-level stress that affected some results on day 2. Oxidative burst, phagocytosis, lysozyme, leucocyte populations other than lymphocytes and A. salmonicida-specific IgM production were not affected by exposure to effluent, and of these parameters, only oxidative burst and total leucocytes showed sampling day effects. From these results it can be observed, that with the exception of oxidative burst, those variables affected by effluent exposure were also significantly changed by the low-level sampling stress imposed by staggered sampling. Elevated liver mixed-function oxygenase activity as measured by 7-ethoxyresorufin-O-deethylase activity, and increased bile polycyclic aromatic hydrocarbon (PAH) metabolites were observed in response to sewage effluent exposure. As both PAHs and stress are known immune suppressors, it is difficult to conclude whether or not changes in immune

  19. Chronic exposure to dietary selenomethionine increases gonadal steroidogenesis in female rainbow trout

    Energy Technology Data Exchange (ETDEWEB)

    Wiseman, Steve, E-mail: steve.wiseman@usask.ca [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N 5B3 (Canada); Thomas, Jith K.; Higley, Eric; Hursky, Olesya [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N 5B3 (Canada); Pietrock, Michael [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N 5B3 (Canada); Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, S7N 5B4 (Canada); Raine, Jason C. [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N 5B3 (Canada); Giesy, John P. [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N 5B3 (Canada); Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, S7N 5B4 (Canada); Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong (Hong Kong); School of Biological Sciences, University of Hong Kong, Hong Kong (Hong Kong); Department of Zoology, Center for Integrative Toxicology, Michigan State University, East Lansing, MI 48824 (United States); State Key Laboratory of Pollution Control and Resource Reuse and School of the Environment, Nanjing University, Nanjing (China); Janz, David M. [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N 5B3 (Canada); Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, S7N 5B4 (Canada); Hecker, Markus [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N 5B3 (Canada); School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK, S7N 5C8 (Canada)

    2011-10-15

    Selenomethionine (Se-Met) is the major dietary form of selenium (Se). Detrimental effects have been associated with exposure to elevated dietary selenium. Previous studies have demonstrated effects of Se on the endocrine system, in particular effects on cortisol and thyroid hormones. However, no information is available regarding effects of Se on sex steroid hormones. In the present study, effects of dietary exposure to an environmentally relevant concentration (4.54 mg/kg wet weight (ww)) of Se-Met for 126 days on concentrations of sex steroid hormones in blood plasma of female rainbow trout were determined. Furthermore, the molecular basis for effects of Se-Met on plasma sex steroid hormone concentrations was investigated. Concentrations of androstenedione (A), estrone (E1), and estradiol (E2) were 39.5-, 3.8-, and 12.7-fold greater in plasma of treated females than the untreated controls, respectively. Testosterone (T) was detected only in plasma of treated females. The greater E2 concentration stimulated greater transcript abundance of vitellogenin (vtg) and zona-radiata protein (zrp). Female rainbow trout exposed to Se-Met had greater transcript abundance of key steroidogenic proteins and enzymes, including peripheral benzodiazepine receptor (pbr), cytochrome P450 side-chain cleavage (P450scc), and 3{beta}-hydroxysteroid dehydrogenase (3{beta}-hsd). Exposure to Se-Met did not affect transcript abundance of luteinizing hormone (lh) or follicle stimulating hormone (fsh). Similarly, there was no change in transcript abundance of luteinizing hormone receptor (lhr) or follicle stimulating hormone receptor (fshr). Long-term exposure to dietary Se-Met has the potential to stimulate vitellogenesis in female rainbow trout by directly stimulating ovarian tissue steroidogenesis. This is the first study to report effects of Se on sex steroid hormone production in fish.

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

    International Nuclear Information System (INIS)

    Forseth, T.; Ugedal, O.; Jonsson, B.; Langeland, A.; Njaastad, O.

    1991-01-01

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

  1. Admixture analysis and stocking impact assessment in brown trout ( Salmo trutta ), estimated with incomplete baseline data

    DEFF Research Database (Denmark)

    Hansen, Michael Møller; Eg Nielsen, Einar; Bekkevold, Dorte

    2001-01-01

    the populations contributing to admixture. We applied the method to analyse the genetic contribution of domesticated brown trout (Salmo trutta) in samples of anadromous trout from two stocked populations with no genetic data available before stocking. Further, we estimated population level admixture proportions...... by the mean of individual admixture coefficients. This method proved more informative than a multidimensional scaling analysis of individual-based genetic distances and assignment tests. The results showed almost complete absence of stocked, domesticated trout in samples of trout from the rivers. Consequently......, stocking had little effect on improving fisheries. In one population, the genetic contribution by domesticated trout was small, whereas in the other population, some genetic impact was suggested. Admixture in this sample of anadromous trout despite absence of stocked domesticated trout could be because...

  2. Tissue astaxanthin and canthaxanthin distribution in rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar).

    Science.gov (United States)

    Page, G I; Davies, S J

    2006-01-01

    A comparative investigation of tissue carotenoid distribution between rainbow trout, Oncorhynchus mykiss, and Atlantic salmon, Salmo salar, was undertaken to identify the relative efficiency of utilization of astaxanthin and canthaxanthin. Higher apparent digestibility coefficients (ADCs) (96% in trout vs. 28-31% in salmon; Ptrout vs. 5.5% in salmon; Ptrout. Astaxanthin deposition was higher than canthaxanthin in rainbow trout, while the reverse was true for Atlantic salmon, suggesting species-specificity in carotenoid utilization. The white muscle (95% in trout vs. 93% in salmon) and kidneys (0.5% in trout vs. 0.2% in salmon) represented higher proportions of the total body carotenoid pool in rainbow trout than in Atlantic salmon (Ptrout; Ptrout. Liver catabolism is suspected to be a critical determinant in carotenoid clearance, with higher catabolism expected in Atlantic salmon than in rainbow trout.

  3. Lake trout demographics in relation to burbot and coregonine populations in the Algonquin Highlands, Ontario

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    Hughes, S.G.

    1985-01-01

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

  5. Safety on North Carolina and Kentucky trout farms.

    Science.gov (United States)

    Ogunsanya, T J; Durborow, R M; Myers, M L; Cole, H P; Thompson, S L

    2011-01-01

    The objective of this study was to identify and describe work-related safety hazards, injuries, and near-injury events (close calls) that occurred on trout farms in North Carolina and Kentucky. An interview instrument was used to collect information on occupational hazards, injuries, and near-injury events that resulted from work-related activities. Trout farmers reported occupational hazards including falling live tank lids, slippery surfaces on hauling trucks, lifting strains, falls from raceway walls and walkways, needlesticks while vaccinating fish, allergies, hypothermia/drowning, falls from cranes, chemical exposure, fire/explosions related to oxygen exposure, and electrical contact with overhead power lines. This study also reports solutions suggested by farm safety researchers or used by farmers to prevent the safety hazards found on trout farms.

  6. Organic contaminants in thermal plume resident brown trout

    International Nuclear Information System (INIS)

    Romberg, G.P.; Bourne, S.

    1978-01-01

    A pilot study was conducted to identify possible contaminants accumulated by thermal plume-resident fish in Lake Michigan. Brown trout were maintained in tanks receiving intake and discharge (less than or equal to 21 0 C) water from a power plant and were fed a diet of frozen alewife. Fish were sampled over a period of 127 days in order to estimate uptake rates and equilibrium levels for toxic organic and inorganic materials occurring in Lake Michigan fish and water. Experimental fish and natural samples were analyzed to determine the distribution of contaminants in various tissues and the corresponding pollutant levels in similar size brown trout from Lake Michigan. The quantitative analyses for the major organic contaminants are summarized. Without exception, the pyloric caecum of brown trout contained the highest concentration of lipids, PCB's, and chlorinated pesticides. Gill and kidney samples contained lower concentrations of contaminants than the caecum, while liver and muscle values were lowest

  7. Gyrodactylid Ectoparasites in a Population of Rainbow Trout (Oncorhynchus mykiss)

    Science.gov (United States)

    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

  8. MORPHOMETRIC CHARACTERISTICS OF THE REPLACEMENT-BROOD STOCK OF RAINBOW TROUT (ONCORHYNCHUS MYKISS (WALBAUM, 1792 REARED IN THE CONDITIONS OF THE INDUSTRIAL FISH FARM "SLOBODA-BANYLIV”

    Directory of Open Access Journals (Sweden)

    P. Mendrishora

    2017-09-01

    Full Text Available Purpose. To analyze the results of morphometric measurements and dates of aquaculture-biological characteristics of the young-of-the-year and age-1+ rainbow trout reared under industrial technology at instable conditions of the fish farm “Sloboda-Banyliv”. Methodology. The study has been performed at the industrial fish farm “Sloboda-Banyliv”, Chernivtsi region. The materials for the study were young-of-the-year and age-1+ rainbow trout obtained from the eggs of autumn-spawning form rainbow trout. The young-of-the-year were reared in a 216 m2 tank with stocking density of 255 ind./m2, age-1+ fish were reared in 108 m2 tank with a stocking density of 33 ind./m2 according to generally accepted methods in trout culture. Morphometric measurements of fish were performed according to I.F. Pravdin. Statistical processing of data was carried out in Microsoft Office Excel (2003. The analysis of values was done in the system of absolute values. The analyzed criteria of the measured parameters were their mean values and standard errors (M±m, deviation (σ, variability coefficient (Cv. Fish were fed with the artificial feed with high protein content manufactured by “Biomar” (Denmark. Findings. The studies on rainbow trout rearing under industrial conditions showed that fish body proportions did not change with age, however, the length of their fins decreased. The slenderness coefficient in age-1+ fish decreased insignificantly that is typical with increasing body depth. Despite instable rearing conditions, both young-of-the-year and age-1+ fish were characterized by moderate growth rate and high feed-conversion efficiency. Originality. For the first time, in conditions of Ukraine, a study on the formation of rainbow trout brood stocks in a fish farm with instable rearing conditions was performed with the use of the analysis of phenotypical and productive features. Practical value. The results of the performed work will provide an opportunity to

  9. Factors affecting competitive dominance of rainbow trout over brook trout in southern Appalachian streams: Implications of an individual-based model

    Energy Technology Data Exchange (ETDEWEB)

    Clark, M.E. [Univ. of Tennessee, Knoxville, TN (United States); Rose, K.A. [Oak Ridge National Lab., TN (United States)

    1997-01-01

    We used an individual-based model to examine possible explanations for the dominance of rainbow trout Oncorhynchus mykiss over brook trout Salvelinus fontinalis in southern Appalachian streams. Model simulations were used to quantify the effects on interspecific competition of (1) competitive advantage for feeding sites by rainbow trout, (2) latitudinal differences in stream temperatures, flows, and daylight, (3) year-class failures, (4) lower fecundity of brook trout, and (5) reductions in spawning habitat. The model tracks the daily spawning, growth, and survival of individuals of both species throughout their lifetime in a series of connected stream habitat units (pools, runs, or riffles). Average densities of each species based on 100-year simulations were compared for several levels of each of the five factors and for sympatric and allopatric conditions. Based on model results and empirical information, we conclude that more frequent year-class failures and the lower fecundity of brook trout are both possible and likely explanations for rainbow trout dominance, that warmer temperatures due to latitude and limited spawning habitat are possible but unlikely explanations, and that competitive advantage for feeding sites by rainbow trout is an unlikely explanation. Additional field work should focus on comparative studies of the reproductive success and the early life stage mortalities of brook and rainbow trout among Appalachian streams with varying rainbow trout dominance. 53 refs., 11 figs.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    Flinders, John M.; Magoulick, Daniel D.

    2017-01-01

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

  12. Stable isotope tracing of trout hatchery carbon to sediments and foodwebs of limestone spring creeks

    Energy Technology Data Exchange (ETDEWEB)

    Hurd, Todd M. [Department of Biology, Shippensburg University, 1871 Old Main Dr., Shippensburg, PA 17257 (United States)], E-mail: tmhurd@ship.edu; Jesic, Slaven; Jerin, Jessica L.; Fuller, Nathan W.; Miller, David [Department of Biology, Shippensburg University, 1871 Old Main Dr., Shippensburg, PA 17257 (United States)

    2008-11-01

    Limestone springs support productive ecosystems and fisheries, yet aquaculture may modify or impair these ecosystems. We determined trout hatchery organic contribution to spring creek sediments and foodwebs with natural abundance stable isotope methods. Hatchery feed, waste, and trout were significantly enriched in {delta}{sup 13}C relative to autotrophs and wild fish. Spring creek sediments were enriched in {delta}{sup 13}C toward the hatchery endmember relative to reference streams without hatcheries and relative to a larger larger-order, spring-influenced stream. Contribution of hatchery C to spring creek sediments was greatest during March and associated with greatest sediment %C. Contribution of hatchery C to pollution-tolerant isopod diet was 39-51% in a stream receiving limestone spring water via hatchery effluent. Isopods of one spring creek also relied on hatchery-derived C within one month of hatchery closure. Four years later, less pollution pollution-tolerant amphipods dominated and consumed non-vascular over vascular autotrophs (86%). Isopods of a second spring creek with an active hatchery did not appear to be using hatchery matter directly, but were enriched in {delta}{sup 34}S relative to a spring creek tributary with no hatchery influence. Isopods in both of these streams were relatively enriched in {delta}{sup 15}N, indicating general nutrient enrichment from surrounding agricultural land use. The contribution of hatchery vs. wild fish in diet of herons and egrets was traced with {delta}{sup 13}C of guano. These birds were strongly dependent on stocked trout in a spring creek with a recently closed state trout hatchery, and also near another large, state-run hatchery. Heron dependence on hatchery fish in the spring creek decreased with time since hatchery closure. Use of stable isotope natural abundance techniques in karst spring creeks can reveal stream impairment due to aquaculture, specific C sources to bio-indicating consumers, losses of

  13. Bisphenol A accumulation in eggs disrupts the endocrine regulation of growth in rainbow trout larvae

    Energy Technology Data Exchange (ETDEWEB)

    Birceanu, Oana; Servos, Mark R.; Vijayan, Mathilakath M., E-mail: matt.vijayan@ucalgary.ca

    2015-04-15

    Highlights: • BPA in eggs reduces growth and increases food conversion ratio in trout larvae. • BPA in eggs disrupts larval transcript abundance of genes involved in GH/IGF axis. • BPA in eggs disrupts thyroid hormone receptor mRNA levels. • BPA in eggs consistently suppressed IGF-1rb mRNA levels during early development. - Abstract: Bisphenol A (BPA), a monomer used in the production of plastics and epoxy resins, is ubiquitously present in the aquatic environment. BPA is considered a weak estrogen in fish, but the effects of this chemical on early developmental events are far from clear. We tested the hypothesis that BPA accumulation in eggs, mimicking maternal transfer, disrupts growth hormone/insulin-like growth factor (GH/IGF) axis function, leading to defects in larval growth in rainbow trout. Trout oocytes were exposed to 0 (control), 0.3, 3, and 30 μg ml{sup −1} BPA for 3 h, which led to an accumulation of around 0, 1, 4 and 40 ng BPA per egg, respectively. All treatment groups were fertilized with clean milt and reared in clean water for the rest of the experiment. The embryo BPA content declined over time in all groups and was completely eliminated by 42 days post-fertilization (dpf). Hatchlings from BPA accumulated eggs had higher water content and reduced total energy levels prior to first feed. There was an overall reduction in the specific growth rate and food conversion ratio in larvae reared from BPA-laden eggs. BPA accumulation disrupted the mRNA abundance of genes involved in GH/IGF axis function, including GH isoforms and their receptors, IGF-1 and -2 and IGF receptors, in a life stage-dependent manner. Also, there was a temporal disruption in the mRNA levels of thyroid hormone receptors in the larvae raised from BPA-laden eggs. Altogether, BPA accumulation in eggs, mimicking maternal transfer, affects larval growth and the mode of action involves disruption of genes involved in the GH/IGF and thyroid axes function in trout.

  14. Bisphenol A accumulation in eggs disrupts the endocrine regulation of growth in rainbow trout larvae

    International Nuclear Information System (INIS)

    Birceanu, Oana; Servos, Mark R.; Vijayan, Mathilakath M.

    2015-01-01

    Highlights: • BPA in eggs reduces growth and increases food conversion ratio in trout larvae. • BPA in eggs disrupts larval transcript abundance of genes involved in GH/IGF axis. • BPA in eggs disrupts thyroid hormone receptor mRNA levels. • BPA in eggs consistently suppressed IGF-1rb mRNA levels during early development. - Abstract: Bisphenol A (BPA), a monomer used in the production of plastics and epoxy resins, is ubiquitously present in the aquatic environment. BPA is considered a weak estrogen in fish, but the effects of this chemical on early developmental events are far from clear. We tested the hypothesis that BPA accumulation in eggs, mimicking maternal transfer, disrupts growth hormone/insulin-like growth factor (GH/IGF) axis function, leading to defects in larval growth in rainbow trout. Trout oocytes were exposed to 0 (control), 0.3, 3, and 30 μg ml −1 BPA for 3 h, which led to an accumulation of around 0, 1, 4 and 40 ng BPA per egg, respectively. All treatment groups were fertilized with clean milt and reared in clean water for the rest of the experiment. The embryo BPA content declined over time in all groups and was completely eliminated by 42 days post-fertilization (dpf). Hatchlings from BPA accumulated eggs had higher water content and reduced total energy levels prior to first feed. There was an overall reduction in the specific growth rate and food conversion ratio in larvae reared from BPA-laden eggs. BPA accumulation disrupted the mRNA abundance of genes involved in GH/IGF axis function, including GH isoforms and their receptors, IGF-1 and -2 and IGF receptors, in a life stage-dependent manner. Also, there was a temporal disruption in the mRNA levels of thyroid hormone receptors in the larvae raised from BPA-laden eggs. Altogether, BPA accumulation in eggs, mimicking maternal transfer, affects larval growth and the mode of action involves disruption of genes involved in the GH/IGF and thyroid axes function in trout

  15. The effect of vacuum packaging on physicochemical changes in rainbow trout (Oncorhynchus mykiss during cold storage

    Directory of Open Access Journals (Sweden)

    František Ježek

    2014-01-01

    Full Text Available The aim of the study was to monitor changes in selected physical (awwater activity, pH values and chemical (TVBN total volatile basic nitrogen, TMA-N trimethylamine nitrogen, FFA free fatty acids, PV peroxide values, TBA thiobarbituric acid value properties in the shelf life of rainbow trout (Oncorhynchus mykiss muscle. A total of 192 trout were examined. Control samples (96 samples were simply packaged in contact with atmospheric oxygen, while experimental samples (96 samples were packaged in a commercial vacuum (98%. All the samples were stored at 2 ± 2° C for 11 days. Analyses were performed on storage days 1, 2, 4, 7, 9, and 11. During the experiment, aw values increased in both types of packaging (in air: 0.982; vacuum-packaged: 0.989. At the end of storage, TVBN and TMA concentrations were at 28.88 ± 4.42 and 19.28 ± 3.00 g mg·100-1, respectively, in the muscle of vacuum-packaged trout; and at 30.52 ± 2.91 and 19.94 ± 2.05 mg·100 g-1, respectively, in fish in simple packaging. The FFA content in vacuum-packaged fish initially declined before increasing to 3.67 ± 2.37% of total fat as oleic acid later in the experiment. The pattern of PV changes was inconclusive, and significant changes (P -1 in vacuum-packaged fish and to 26.03 ± 8.00 mg·kg-1 in fish in simple packaging. Free fatty acids are not a good indicator of spoilage because they are converted to hydroperoxides. Vacuum packaging effectively slowed down oxidative changes in rainbow trout muscle. The peroxide content is not a suitable indicator of shelf life as peroxides are decomposed to secondary products. Total volatile basic nitrogen and thiobarbituric acid value can be recommended as suitable indicators of freshness and shelf life.

  16. Oxidative stress and partial migration in brown trout (Salmo trutta)

    DEFF Research Database (Denmark)

    Birnie-Gauvin, Kim; Peiman, K. S.; Larsen, Martin Hage

    2017-01-01

    of oxidative status in migration biology, particularly in fish. Semi-anadromous brown trout (Salmo trutta, Linnaeus 1758) exhibit partial migration, where some individuals smoltify and migrate to sea, and others become stream residents, providing us with an excellent model to investigate the link between...... oxidative stress and migration. Using the brown trout, we obtained blood samples from juveniles from a coastal stream in Denmark in the fall prior to peak seaward migration which occurs in the spring, and assayed for antioxidant capacity (oxygen radical absorbance capacity) and oxidative stress levels...

  17. Animal welfare in brown trout farming: hematological results

    Directory of Open Access Journals (Sweden)

    G. Forneris

    2010-01-01

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

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

    DEFF Research Database (Denmark)

    Lorenzen, Niels; Lapatra, S.E.

    1999-01-01

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

  19. Cloning and characterization of transferrin cDNA and rapid detection of transferrin gene polymorphism in rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Tange, N; Jong-Young, L; Mikawa, N; Hirono, I; Aoki, T

    1997-12-01

    A cDNA clone of rainbow trout (Oncorhynchus mykiss) transferrin was obtained from a liver cDNA library. The 2537-bp cDNA sequence contained an open reading frame encoding 691 amino acids and the 5' and 3' noncoding regions. The amino acid sequences at the iron-binding sites and the two N-linked glycosylation sites, and the cysteine residues were consistent with known, conserved vertebrate transferrin cDNA sequences. Single N-linked glycosylation sites existed on the N- and C-lobe. The deduced amino acid sequence of the rainbow trout transferrin cDNA had 92.9% identities with transferrin of coho salmon (Oncorhynchus kisutch); 85%, Atlantic salmon (Salmo salar); 67.3%, medaka (Oryzias latipes); 61.3% Atlantic cod (Gadus morhua); and 59.7%, Japanese flounder (Paralichthys olivaceus). The long and accurate polymerase chain reaction (LA-PCR) was used to amplify approximately 6.5 kb of the transferrin gene from rainbow trout genomic DNA. Restriction fragment length polymorphisms (RFLPs) of the LA-PCR products revealed three digestion patterns in 22 samples.

  20. [Effect of a supplemental Aspergillus niger phytase on the utilization of plant phosphorus by rainbow trout (Oncorhynchus mykiss)].

    Science.gov (United States)

    Rodehutscord, M; Becker, A; Pfeffer, E

    1995-01-01

    Effects of a supplemental Aspergillus niger-phytase on digestibility and utilization of dietary phosphorus (P) were studied in three experiments with rainbow trout. P concentration in the diets was 4.8 and 5.8 g/kg DM, respectively. The P contained in the diet originated solely from plants, mainly soy-products. Digestibility of P was studied using the stripping method and hydrochloride insoluble ash as marker. Utilization was studied in growth trials by use of the comparative body analysis. At a water temperature of 15 degrees C, both digestibility and utilization of P were increased from 25 to 57% and from 17 to 49%, respectively when 1000 U/kg phytase were supplemented. Feed consumption and gain of trout were significantly increased. At a water temperature of 10 degrees C, utilization of P was also increased from 6 to 25%. However, feed consumption and gain of trout were very low at this water temperature and not influenced by the supplemental phytase.

  1. The Effect of Mycotoxin Deoxynivalenol on Haematological and Biochemical Indicators and Histopathological Changes in Rainbow Trout (Oncorhynchus mykiss

    Directory of Open Access Journals (Sweden)

    Iveta Matejova

    2014-01-01

    Full Text Available Deoxynivalenol (DON, produced by the Fusarium genus, is a major contaminant of cereal grains used in the production of fish feed. The effect of mycotoxin deoxynivalenol on rainbow trout (Oncorhynchus mykiss was studied using a commercial feed with the addition of DON in a dose of 2 mg/kg feed. The fish (n=40 were exposed to the mycotoxin for 23 days. The trout were divided into two groups, control and experimental groups. Control groups were fed a commercial feed naturally contaminated with a low concentration of DON (225 μg/kg feed; experimental groups were fed a commercial feed with the addition of DON (1964 μg/kg feed. Plasma biochemical and haematological indices, biometric parameters, and histopathological changes were assessed at the end of the experiment. The experimental groups showed significantly lower values in MCH (P<0.05. In biochemical indices, after 23-day exposure, a significant decrease in glucose, cholesterol (P<0.05, and ammonia (P<0.01 was recorded in the experimental group compared to the control group. Our assessment showed no significant changes in biometric parameters. The histopathological examination revealed disorders in the caudal kidney of the exposed fish. The obtained data show the sensitivity of rainbow trout (O. mykiss to deoxynivalenol.

  2. The combine effects of salting and thyme oil on sensory and chemical changes of rainbow trout (Oncorhynchus mykiss) fillets

    Science.gov (United States)

    Yildiz, Pınar Oǧuzhan

    2016-04-01

    The present study aimed to investigate the combine effects of salting and thyme oil on chemical and sensory changes of rainbow trout (Oncorhynchus mykiss) during storage (4°C) was investigated over a period of 24 days. There groups were constituted: group A-control salted, group B-salted samples with 0.4% of thyme oil and group C-salted samples with 0.8% of thyme oil. Fillets were subject to chemical (thiobarbituric acid reactive substances-TBARS, total volatile base nitrogen-TVB-N) and sensory analyses on certain days (0, 3, 6, 9, 12, 15, 18, 21 and 24th days) of storage. Five experienced panelists, academic staff who were trained in sensory descriptors for fishes, were employed to evaluate the quality of trout fillets during storage. Rainbow trout fillets were assessed on the basis of appearance, taste, texture and odour characteristics using a nine point descriptive scale. TVB-N and TBARS values increased in the duration of storage time in all groups. TVB-N and TBARS values in control groups were higher than other groups. Group C samples were assessed as the most acceptable products by the panellists. Difference in chemical and sensory changes between samples was found to be significant (p<0.05) during storage period.

  3. Native and exotic fishes in a Patagonian reservoir with rainbow trout cage culture: spatial and trophic resource use

    Directory of Open Access Journals (Sweden)

    Nabaes Jodar Diego N.

    2017-01-01

    Full Text Available Although the interactions of exotic salmonids with native Patagonian fishes are well known, little is known about the ecology and impact of farmed fish escapees. Salmonid production in Argentina is largely concentrated in the Alicurá reservoir in north Patagonia, where fish community studies have been scarce. Here, we assess and compare the spatial distribution, body size–condition and diet of the different fish species in this reservoir. Strong vertical segregation was observed between exotic rainbow trout Oncorhynchus mykiss (both escapees and wild, dominating the littoral zone, and native Percichthys trucha which dominate the medium and deep strata. Low piscivory–benthivory and high zooplanktivory were observed for rainbow trout, both traits being uncommon at a regional scale. Escaped farmed rainbow trout (ERT diet included abundant indigestible items along with wild prey. Higher body condition of P. trucha close to farms, as well as the regionally unprecedented high incidence of Daphnia sp. in the guts of all the species suggest that farm nutrient discharges have had significant impacts. Finally, the high body condition of ERT, together with their wild food diet and the long dispersal distance observed, demonstrate post-escape success, drawing our attention to potential upstream dispersion affecting the biodiversity and fisheries of Patagonian rivers and lakes.

  4. Characterization of a novel alpha-amidated decapeptide derived from proopiomelanocortin-A in the trout pituitary.

    Science.gov (United States)

    Tollemer, H; Leprince, J; Bailhache, T; Chauveau, I; Vandesande, F; Tonon, M C; Jego, P; Vaudry, H

    1997-01-01

    Two complementary DNAs encoding distinct forms of POMC have been characterized in the trout pituitary. One of the POMC variants (POMC-A) possesses a C-terminal extension of 25 amino acids, which has no equivalent in other POMCs described to date. This C-terminal peptide contains three pairs of basic amino acids, suggesting that it may be the precursor of multiple processed peptides. In addition, the presence of a C-terminal glycine residue suggests that some of the processing products may be alpha-amidated. To characterize the molecular forms of the peptides generated from the C-terminal domain of trout POMC-A, we have developed specific antibodies against the C-terminal pentapeptide YHFQG and its alpha-amidated derivative YHFQ-NH2. Immunocytochemical labeling of pituitary sections with antibodies against YHFQ-NH2 revealed the presence of numerous immunoreactive cells in the pars intermedia and the rostral pars distalis. In contrast, the antibodies against YHFQG produced only weak immunostaining. HPLC analysis combined with RIA detection revealed that extracts of the pars intermedia and pars distalis contain several peptides derived from the C-terminal extension of trout POMC-A, with the predominant molecular form exhibiting the same retention time as ALGERKYHFQ-NH2. Tryptic digestion of this major form produced a peptide that coeluted with YHFQ-NH2. These data indicate that the processing of the C-terminal extension of trout POMC-A generates several novel peptides including the decapeptide amide ALGERKYHFQ-NH2.

  5. Using observed load distributions with a simple model to analyse the epidemiology of sea lice (Lepeophtheirus salmonis) on sea trout (Salmo trutta).

    Science.gov (United States)

    Murray, Alexander G

    2002-06-01

    Sea lice are ectoparasites of salmonids that have been associated with the recent decline in sea trout numbers in north-west Europe. Observed patterns of louse load distribution between sea trout in the seas surrounding the UK, Ireland and Norway and a simple model have been used to analyse the epidemiology of lice. Loads are aggregated and deviate strongly from the Poisson distribution, although less than is observed with many other parasites. The louse numbers on fish from offshore sites are slightly less variable than for fish from coastal sites with comparable mean loads. Analysis of louse development stages and sexes shows that selection between hosts by sea lice plays a limited role. If host selection is absent, then associated poor condition would be caused by, not the cause of, high louse burdens; however the absence of such selection is not proved. Scenarios with infection that is patchy in space and time best generate the aggregated load patterns observed; these patches accord with observed swarms of copepodids. Prevalence patterns may indicate the movement of trout between environments. Control of copepodids in infection 'hot spots', either directly or through control of louse egg production in their catchment, may reduce louse loads on wild sea trout and, in particular, extreme and damaging loads.

  6. Cannibalism in non-native brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss stream-dwelling populations.

    Science.gov (United States)

    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.

  7. Microsatellite and mitochondrial DNA polymorphism reveals life history dependent interbreeding between hatchery and wild brown trout ( Salmo trutta L.)

    DEFF Research Database (Denmark)

    Hansen, Michael Møller; Ruzzante, D.E.; Eg Nielsen, Einar

    2000-01-01

    The effects of stocking hatchery trout into wild populations were studied in a Danish river, using microsatellite and mitochondrial DNA (mtDNA) markers. Baseline samples were taken from hatchery trout and wild trout assumed to be unaffected by previous stocking. Also, samples were taken from...... resident and sea trout from a stocked section of the river. Genetic differentiation between the hatchery strain and the local wild population was modest (microsatellite F-ST = 0.06). Using assignment tests, more than 90% of individuals from the baseline samples were classified correctly. Assignment tests...... involving samples from the stocked river section suggested that the contribution by hatchery trout was low among sea trout (trout. Hybrid index analysis and a high percentage of mtDNA haplotypes specific to indigenous trout observed among resident trout that were assigned...

  8. Passage survival of juvenile steelhead, coho salmon, and Chinook salmon in Lake Scanewa and at Cowlitz Falls Dam, Cowlitz River, Washington, 2010–16

    Science.gov (United States)

    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

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

    Science.gov (United States)

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

    2013-01-01

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

  10. PCDD/F, dioxin-like and markers PCBs in trouts from French aquaculture

    Energy Technology Data Exchange (ETDEWEB)

    Marchand, P.; Matayron, G.; Gade, C.; Le Bizec, B.; Andre, F. [LABERCA-ENVN, Nantes (France)

    2004-09-15

    Since the introduction of 12 ''dioxin-like'' polychlorinated biphenyls (PCBs) into the assessment of a tolerable daily intake (TDI) for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) by the World Health Organization (WHO) in 1998, the analytical determination of nonand mono-ortho PCBs is of increasing interest in the scientific community. The European Commission has already published a regulation that sets maximum limits for dioxins in foodstuffs (Council Regulation 2375/01/EC amending Commission regulation (EC) N 466/2001 setting maximum levels for certain contaminants in foodstuffs). As an additional feature of the reduction strategy for this group of compounds, the European Commission has planned to include the dioxinlike PCBs in the limit values for food and feeding stuffs starting at the end of 2004. The LABERCA (French National Reference Laboratory for dioxins and dioxin-like PCBs (DL-PCBs)) and the CIPA (French Interprofessional Committee for Aquaculture products) reported levels in French farmed trout according to WHO-TEQ expression and sum of Markers PCBs (m-PCBs). It must be emphasized that this survey only represents a snapshot in time. The results cannot be used to determine the potential contamination of other batches that have not been tested. However, the fish samples were taken from 58 aquaculture sites and 10 fishes were pooled from each site. It is the reason why the results can be interpreted as a good indicative of the contamination levels in farmed trout produced in France.

  11. Profiling of androgen response in rainbow trout pubertal testis: relevance to male gonad development and spermatogenesis.

    Directory of Open Access Journals (Sweden)

    Antoine D Rolland

    Full Text Available The capacity of testicular somatic cells to promote and sustain germ cell differentiation is largely regulated by sexual steroids and notably androgens. In fish species the importance of androgens is emphasized by their ability to induce sex reversal of the developing fries and to trigger spermatogenesis. Here we studied the influence of androgens on testicular gene expression in trout testis using microarrays. Following treatment of immature males with physiological doses of testosterone or 11-ketotestosterone, 418 genes that exhibit changes in expression were identified. Interestingly, the activity of testosterone appeared stronger than that of 11-ketotestosterone. Expression profiles of responsive genes throughout testis development and in isolated germ cells confirmed androgens to mainly affect gene expression in somatic cells. Furthermore, specific clusters of genes that exhibit regulation coincidently with changes in the natural circulating levels of androgens during the reproductive cycle were highlighted, reinforcing the physiological significance of these data. Among somatic genes, a phylogenetic footprinting study identified putative androgen response elements within the proximal promoter regions of 42 potential direct androgen target genes. Finally, androgens were also found to alter the germ line towards meiotic expression profiles, supporting the hypothesis of a role for the somatic responsive genes in driving germ cell fate. This study significantly increases our understanding of molecular pathways regulated by androgens in vertebrates. The highly cyclic testicular development in trout together with functions associated with regulated genes reveal potential mechanisms for androgen actions in tubule formation, steroid production, germ cell development and sperm secretion.

  12. Effect of ellagic acid on some haematological, immunological and antioxidant parameters of rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Mişe Yonar, S; Yonar, M E; Yöntürk, Y; Pala, A

    2014-10-01

    In this study, effect of ellagic acid on some haematological, immunological and antioxidant parameters in the blood and various tissues of rainbow trout (Oncorhynchus mykiss) were examined. Four groups of rainbow trout were fed experimental diets containing either no ellagic acid (control) or supplemented with ellagic acid at 50 mg/kg diet (EA-50), 100 mg/kg diet (EA-100) or 150 mg/kg diet (EA-150) for 21 days. Samples of the blood and tissue (liver, kidney and spleen) were collected at the end of the experiment and analysed for their haematological profile (the red blood cell count, the haemoglobin concentration and the haematocrit level), immune response (the white blood cell count, the oxidative radical production (NBT activity), the total plasma protein and total immunoglobulin level) and oxidant/antioxidant status (the malondialdehyde level, the superoxide dismutase, catalase and glutathione peroxidase activity as well as the reduced glutathione concentration). The findings of this study demonstrated that ellagic acid had a positive effect on the haematological parameters, the immune response and the antioxidant enzyme activities of the fish. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

  13. BIOMASS AND DENSITY OF BROWN AND RAINBOW TROUT IN NEW MEXICO STREAMS

    Directory of Open Access Journals (Sweden)

    Srečko Lainer

    1995-03-01

    Full Text Available Mean stream numerical density of the brown trout (Salmo trutta m. fario Linnaeus, 1758 and the rainbow trout (Onchorhynchus mykiss Walbaum, 1792 was 0.090 fish/m2 of which brown trout averaged 69% (72% in total biomass in 15 high-elevation New Mexico streams (1,661-2,560 m above sea level. Total trout density varied from 0.008/m2 in 1988 and 1989. Mean trout density ranged between 0.023-0.121 fish/m2 at site s open to public fishing. Considerably higher densities (0.142-0.409 fish/m2 were observed at sites closed for fishing. In the seven selected streams shared by both species, brown trout density exceeded rainbow trout density except at the two sites closed to fishing. Brown trout were stocked only as fingerlings (average 7,000 fish/stream/year while rainbow trout were stocked only in harvestable sizes (11,000 fish/stream/year. Reported total trout yield rates exceeded the total number of fish estimated to be in the stream by 1.01 to 11.63 in most small streams open to fishing. The proportional stock density (PSD ranged between O and 50 percent. Streams with low to moderate intensities of fishing had the highest PSD.

  14. Use of wild trout for PBDE assessment in freshwater environments: Review and summary of critical factors

    Directory of Open Access Journals (Sweden)

    Juan M. Ríos

    2015-11-01

    Full Text Available Certain wild animals represent sentinels to address issues related to environmental pollution, since they can provide integrative data on both pollutant exposure and biological effects. Despite their technological benefits, PBDEs are considered a threat to environmental health due to their persistence, toxicity, and capacity to be accumulated. These pollutants have been found geographically widespread in fish, particularly in predator species such as trout. The aim of this work is to critically review the applicability and usefulness of wild trout for assessing PBDEs in freshwater environments. Reviewed reports include data from highly industrialized areas as well as areas from remote regions with relatively low human activity, including European and North American great lakes and freshwater environments in Europe, Greenland, subarctic areas and Patagonia, respectively. A summary of relevant factors were grouped into organism-specific factors (food habits, age, size, lipid content, sex and reproduction, tissue type, mechanism of contaminant uptake and metabolism, and PBDE levels in the surrounding environment (sediment. Five wild trout species [rainbow trout (Oncorhynchus mykiss, brown trout (Salmo trutta, lake trout (Salvelinus namaycush, arctic char (Salvelinus alpinus, and brook trout (Salvelinus fontinalis], collected worldwide within the 1994 to present time frame, were considered. Multivariate techniques (principal component analysis-PCA and mapping approach, showed clear differences in geographic distribution patterns of PBDE levels in trout depending on the region studied: wild trout from European and North American great lakes have the highest PBDE loads. This pattern could be due to high industrial activity at these locations. A correlational approach used to explore intraspecific relationships between PBDE levels and morphometry, showed positive relationships only for brown trout. Further, brown trout showed the highest trout

  15. TheInfluence of Extruded Feed with a high Protein Level Upon the Bioproductive Performances Obtained on the Rainbow Trout Females (Oncorhynchus mykiss

    Directory of Open Access Journals (Sweden)

    Mihaela Ancuta Boaru

    2016-11-01

    Full Text Available The succes ofartificial reproduction in the rainbow trout(Oncorhynchus mykiss, the development of gonads and the results obtained at incubation are significantly affected by the feeding of the breeders. The use of quality sexual  products is decisive for the assurance of the production of viable larvae and further of the estimated fish production, so that in addition to the assurance of optimal environmental parameters, the proper feeding of the breeders is required. Starting from the current stage of knowledge in the field,the main objective of the working paperwas to highlight the way the differentiatedfeeding of the rainbow trout females (Oncorhynchus mykiss influences their growth and development. The extruded peeled feed with a high protein level upon theegg weightand the gonosomatic index were followed. The extruded peeled feed with 53% protein proved to be highly effective, materialized trough high growth performances, a better conversion and the growth of gonadal  weight.

  16. Hood River Production Program Review, Final Report 1991-2001.

    Energy Technology Data Exchange (ETDEWEB)

    Underwood, Keith; Chapman, Colin; Ackerman, Nicklaus

    2003-12-01

    This document provides a comprehensive review of Bonneville Power Administration (BPA) funded activities within the Hood River Basin from 1991 to 2001. These activities, known as the Hood River Production Program (HRPP), are intended to mitigate for fish losses related to operation of federal dams in the Columbia River Basin, and to contribute to recovery of endangered and/or threatened salmon and steelhead, as directed by Nation Oceanic and Atmospheric Administration - Fisheries (NOAA Fisheries). The Environmental Impact Statement (EIS) for the HRPP, which authorized BPA to fund salmon and steelhead enhancement activities in the Hood River Basin, was completed in 1996 (BPA 1996). The EIS specified seven years of monitoring and evaluation (1996-2002) after program implementation to determine if program actions needed modification to meet program objectives. The EIS also called for a program review after 2002, that review is reported here.

  17. Estrogenic response of bisphenol A in rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Lindholst, Christian; Pedersen, Knud Ladegaard; Pedersen, Søren Nørby

    2000-01-01

    Bisphenol A (BPA) previously shown to possess xenoestrogenic activities was administered to rainbow trout (Oncorhynchus mykiss) through a continuos flow system. The estrogenic response expressed as the induction of vitellogenin (VTG) synthesis was measured during 12 days of exposure, using a direct...

  18. DNA Fingerprinting of Trout Lilies: A High School Student Project.

    Science.gov (United States)

    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)

  19. Conservation of native Pacific trout diversity in Western North America

    Science.gov (United States)

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

    2016-01-01

    Pacific trout Oncorhynchus spp. in western North America are strongly valued in ecological, socioeconomic, and cultural views, and have been the subject of substantial research and conservation efforts. Despite this, the understanding of their evolutionary histories, overall diversity, and challenges to their conservation is incomplete. We review...

  20. Sea growth of anadromous brown trout (Salmo trutta)

    NARCIS (Netherlands)

    Leeuw, de J.J.; Hofstede, ter R.; Winter, H.V.

    2007-01-01

    Sea growth rates were studied in anadromous brown trout caught in Lake IJsselmeer, The Netherlands. Growth in the first year at sea was estimated at 26 cm from length-frequency distributions, and at 21 cm from back-calculated growth rates from scale readings. These estimates are considerably higher

  1. Lake Michigan lake trout PCB model forecast post audit

    Science.gov (United States)

    Scenario forecasts for total PCBs in Lake Michigan (LM) lake trout were conducted using the linked LM2-Toxics and LM Food Chain models, supported by a suite of additional LM models. Efforts were conducted under the Lake Michigan Mass Balance Study and the post audit represents th...

  2. Colorado River cutthroat trout: a technical conservation assessment

    Science.gov (United States)

    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. Toxicokinetics of perfluorooctane sulfonate in rainbow trout (Oncorhynchus mykiss)

    Science.gov (United States)

    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...

  4. Impacts of trout on aquatic macroinvertebrates in three Drakensberg ...

    African Journals Online (AJOL)

    Further studies are recommended in order to provide additional information on seasonal variation in these patterns, as well as on density-dependent effects of trout on aquatic macroinvertebrate communities. Keywords: management, Oncorhynchus mykiss, Salmo trutta, Ukhahlamba-Drakensberg Park, waterfalls

  5. Fine Sediment Effects on Brook Trout Eggs in Laboratory Streams

    Science.gov (United States)

    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...

  6. Evaluation of Antioxidant Effects of Water and Ethanolic Extracts of Iranian Pomegranate Seed on Lipid Quality of Trout Fillet and Determining the Level of Perishability at 2-4 ° C

    Directory of Open Access Journals (Sweden)

    Gholam Reza Jahed Khaniky

    2015-08-01

    Full Text Available Background and Aims Because of unsaturated fatty acid content, trout and fish products are highly perishable. For this reason, preservatives are used to prevent or delay spoiling during storage. The aim of this study was determination of antioxidant activities of pomegranate seeds extracts on lipid quality of trout fillet stored at 2-4°C. Materials and Methods Prepared fish fillets were divided into two groups. One group was trout fillet without extract (control and one in pomegranate seeds extracts that were stored in refrigerator for 6 days. Chemical tests such as Peroxide Value (PV, Thiobarbituric Acid Reactive Substances (TBARS, Total Volatile Basic Nitrogen (TVB-N and Free Fatty Acids (FFA were used to determine perishability of trout fillet. Results The PV, TBA, TVB-N and FFA were significantly (P < 0.05 lowest in the samples treated with ethanolic extracts of pomegranate seeds as compared to control group. (PV = 2.62 meq o2/kg, TBA = 1.26 mg MDA/kg, TVB-N = 22.13 mg/100g and FFA = 1.2 percent Oleic acid. Conclusion The result of this study demonstrated that pomegranate seeds extracts were efficiency to prevent lipid oxidation in trout fillet stored at refrigerator temperature. * Corresponding Author: Tehran University of Medical Sciences, School of Public Health. Email: Salehia15@gmail.com

  7. Surgically Implanted JSATS Micro-Acoustic Transmitters Effects on Juvenile Chinook Salmon and Steelhead Tag Expulsion and Survival, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Woodley, Christa M.; Carpenter, Scott M.; Carter, Kathleen M.; Wagner, Katie A.; Royer, Ida M.; Knox, Kasey M.; Kim, Jin A.; Gay, Marybeth E.; Weiland, Mark A.; Brown, Richard S.

    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 5 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 indoor

  8. Feed based on vegetable materials changes the muscle proteome of the carnivore rainbow trout

    DEFF Research Database (Denmark)

    Jessen, Flemming; Wulff, Tune; Bach Mikkelsen, J.

    2011-01-01

    Feed production for aquaculture of carnivore fish species relies heavily on protein and lipid from the limited resources of wild fish and other sea living organisms. Thus the development of alternative feeds replacing fish meal and oil with components of vegetable origin is important for a sustai......Feed production for aquaculture of carnivore fish species relies heavily on protein and lipid from the limited resources of wild fish and other sea living organisms. Thus the development of alternative feeds replacing fish meal and oil with components of vegetable origin is important...... trout fed two different diets identical in protein and oil content, but with diet C based on fish meal and oil and diet V based on rapeseed oil and vegetable proteins. In addition to the proteomic investigation the textural properties of the fish were analysed by sensory profiling. Protein expression...

  9. Large predatory coral trout species unlikely to meet increasing energetic demands in a warming ocean

    KAUST Repository

    Johansen, J.L.

    2015-09-08

    Increased ocean temperature due to climate change is raising metabolic demands and energy requirements of marine ectotherms. If productivity of marine systems and fisheries are to persist, individual species must compensate for this demand through increasing energy acquisition or decreasing energy expenditure. Here we reveal that the most important coral reef fishery species in the Indo-west Pacific, the large predatory coral trout Plectropomus leopardus (Serranidae), can behaviourally adjust food intake to maintain body-condition under elevated temperatures, and acclimate over time to consume larger meals. However, these increased energetic demands are unlikely to be met by adequate production at lower trophic levels, as smaller prey species are often the first to decline in response to climate-induced loss of live coral and structural complexity. Consequently, ubiquitous increases in energy consumption due to climate change will increase top-down competition for a dwindling biomass of prey, potentially distorting entire food webs and associated fisheries.

  10. Effects of Levamisole on Phagocytic Activity of Rainbow Trout (Oncorhynchus mykiss W.

    Directory of Open Access Journals (Sweden)

    U. Ispir

    2007-01-01

    Full Text Available In this study, activation of phagocytic cells was examined in rainbow trout (Oncorhynchus mykiss W. exposed to 1, 5 and 10 μg ml-1 concentrations of levamisole solution. For this purpose, blood samples were taken from fish on days 1, 7 and 14 of exposure. Potential killing activity was determined by measuring oxidative radical production and phagocytic activity of neutrophils and superoxide anion production of phagocytic cells against Y. ruckeri. The activity of phagocytic cells in fish exposed to each of three concentrations was found higher than that in controls and the differences were statistically significant (p p -1 concentration of levamisole solution was determined on day 7, it was observed that all indicators increased on day 14 of exposure. The present results suggest that the application of levamisole in fish farms could increase non-specific immunity and resistance to infection of fish and offer economics benefits.

  11. Large predatory coral trout species unlikely to meet increasing energetic demands in a warming ocean

    KAUST Repository

    Johansen, J.L.; Pratchett, M.S.; Messmer, V.; Coker, Darren James; Tobin, A.J.; Hoey, A.S.

    2015-01-01

    Increased ocean temperature due to climate change is raising metabolic demands and energy requirements of marine ectotherms. If productivity of marine systems and fisheries are to persist, individual species must compensate for this demand through increasing energy acquisition or decreasing energy expenditure. Here we reveal that the most important coral reef fishery species in the Indo-west Pacific, the large predatory coral trout Plectropomus leopardus (Serranidae), can behaviourally adjust food intake to maintain body-condition under elevated temperatures, and acclimate over time to consume larger meals. However, these increased energetic demands are unlikely to be met by adequate production at lower trophic levels, as smaller prey species are often the first to decline in response to climate-induced loss of live coral and structural complexity. Consequently, ubiquitous increases in energy consumption due to climate change will increase top-down competition for a dwindling biomass of prey, potentially distorting entire food webs and associated fisheries.

  12. Growth of juvenile steelhead Oncorhynchus mykiss under size-selective pressure limited by seasonal bioenergetic and environmental constraints

    Science.gov (United States)

    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.

  13. Prebiotic Supplementation has Only Minimal Effects on Growth Efficiency, Intestinal Health and Disease Resistance of Westslope Cutthroat Trout Oncorhynchus clarkii lewisi Fed 30% Soybean Meal.

    Science.gov (United States)

    Sealey, Wendy M; Conley, Zachariah B; Bensley, Molly

    2015-01-01

    Prebiotics have successfully been used to prevent infectious diseases in aquaculture and there is an increasing amount of literature that suggests that these products can also improve alternative protein utilization and digestion. Therefore, the objective of this study was to examine whether prebiotic supplementation increased the growth efficiency, intestinal health, and disease resistance of cutthroat trout fed a high level of dietary soybean meal. To achieve this objective, juvenile Westslope cutthroat trout (Oncorhynchus clarkii lewisi) were fed a practical type formulation with 0 or 30% dietary soybean meal with or without the commercial prebiotic (Grobiotic-A) prior to experimental exposure to Flavobacterium psychrophilum. Juvenile Westslope cutthroat trout (initial weight 7.8 g/fish ±SD of 0.5 g) were stocked at 30 fish/tank in 75 L tanks with six replicate tanks per diet and fed their respective diets for 20 weeks. Final weights of Westslope cutthroat trout were affected by neither dietary soybean meal inclusion level (P = 0.9582) nor prebiotic inclusion (P = 0.9348) and no interaction was observed (P = 0.1242). Feed conversion ratios were similarly not affected by soybean meal level (P = 0.4895), prebiotic inclusion (P = 0.3258) or their interaction (P = 0.1478). Histological examination of the distal intestine of Westslope cutthroat trout demonstrated increases in inflammation due to both increased soybean meal inclusion level (P = 0.0038) and prebiotic inclusion (P = 0.0327) without significant interaction (P = 0.3370). Feeding dietary soybean meal level at 30% increased mortality of F. psychrophilum cohabitation challenged Westslope cutthroat trout (P = 0.0345) while prebiotic inclusion tended to decrease mortality (P = 0.0671). These results indicate that subclinical alterations in intestinal inflammation levels due to high dietary inclusion levels of soybean meal could predispose Westslope cutthroat

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

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, Jim; McPeak, Ron

    2001-02-01

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

  15. Bull trout population assessment in the Columbia River Gorge/annual report fy2000; ANNUAL

    International Nuclear Information System (INIS)

    Byrne, Jim; McPeak, Ron

    2001-01-01

    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 and lt;15 C and appropriate for spawning and rearing of bull trout. We snorkel surveyed more than 74 km (46.25 mi.) of rivers and streams in the four sub-basins (13.8 km at night and 60.2 km during the day) and found that night snorkeling was superior to day snorkeling for locating bull trout. Surveys incorporated the Draft Interim Protocol for Determining Bull Trout Presence (Peterson et al. In Press). However, due to access and safety issues, we were unable to randomly select sample sites nor use block nets as recommended. Additionally, we also implemented the Bull Trout/Dolly Varden sampling methodology described in Bonar et al. (1997). No bull trout were found in the Wind River, Little White Salmon, or White Salmon River sub-basins. We found bull trout in the West Fork Klickitat drainage of the Klickitat River Sub-basin. Bull trout averaged 6.7 fish/100m(sup 2) in Trappers Creek, 2.6 fish/100m(sup 2) on Clearwater Creek, and 0.4 fish/100m(sup 2) in Little Muddy Creek. Bull trout was the only species of salmonid encountered in Trappers Creek and dominated in Clearwater Creek. Little Muddy Creek was the only creek where bull trout and introduced brook trout occurred together. We found bull trout only at night and typically in low flow regimes. A single fish, believed to be a bull trout x brook trout hybrid, was observed in the Little Muddy Creek. Additional surveys are needed in the West Fork Klickitat and mainstem

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

    Science.gov (United States)

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

    2015-01-01

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

  17. Sanctuaries for lake trout in the Great Lakes

    Science.gov (United States)

    Stanley, Jon G.; Eshenroder, Randy L.; Hartman, Wilbur L.

    1987-01-01

    Populations of lake trout, severely depleted in Lake Superior and virtually extirpated from the other Great Lakes because of sea lamprey predation and intense fishing, are now maintained by annual plantings of hatchery-reared fish in Lakes Michigan, Huron, and Ontario and parts of Lake Superior. The extensive coastal areas of the Great Lakes and proximity to large populations resulted in fishing pressure on planted lake trout heavy enough to push annual mortality associated with sport and commercial fisheries well above the critical level needed to reestablish self-sustaining stocks. The interagency, international program for rehabilitating lake trout includes controlling sea lamprey abundance, stocking hatchery-reared lake trout, managing the catch, and establishing sanctuaries where harvest is prohibited. Three lake trout sanctuaries have been established in Lake Michigan: the Fox Island Sanctuary of 121, 500 ha, in the Chippewa-Ottawa Treaty fishing zone in the northern region of the lake; the Milwaukee Reef Sanctuary of 160, 000 ha in midlake, in boundary waters of Michigan and Wisconsin; and Julian's Reef Sanctuary of 6, 500 ha, in Illinois waters. In northern Lake Huron, Drummond Island Sanctuary of 55, 000 ha is two thirds in Indian treaty-ceded waters in Michigan and one third in Ontario waters of Canada. A second sanctuary, Six Fathom Bank-Yankee Reef Sanctuary, in central Lake Huron contains 168, 000 ha. Sanctuary status for the Canadian areas remains to be approved by the Provincial government. In Lake Superior, sanctuaries protect the spawning grounds of Gull Island Shoal (70, 000 ha) and Devils Island Shoal (44, 000 ha) in Wisconsin's Apostle Island area. These seven sanctuaries, established by the several States and agreed upon by the States, Indian tribes, the U.S. Department of the Interior, and the Province of Ontario, contribute toward solving an interjurisdictional fishery problem.

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

    Science.gov (United States)

    Fatima, Shafaq; Adams, Mark; Wilkinson, Ryan

    2016-12-01

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

  19. Temporal genetic monitoring of hybridization between native westslope cutthroat trout and introduced rainbow trout in the Stehekin River, Washington

    Science.gov (United States)

    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.

  20. Does dispersal from landlocked trout explain the coexistence of resident and migratory trout females in a small stream?

    DEFF Research Database (Denmark)

    Pettersson, J.C.E.; Hansen, Michael Møller; Bohlin, T.

    2001-01-01

    The hypothesis that stream-resident females of brown trout Salmo trutta occurring in sympatry with sea-migrant females in a small stream were immigrants from an up-stream allopatric landlocked population was rejected. Genetic differentiation was not detected between the sympatric forms whereas...

  1. Estimating the long-term effects of stocking domesticated trout into wild brown trout ( Salmo trutta ) populations : an approach using microsatellite DNA analysis of historical and contemporary samples

    DEFF Research Database (Denmark)

    Hansen, Michael Møller

    2002-01-01

    . The study was based on analysis of two historical samples (194556), represented by old scale collections, and seven contemporary samples (1986-2000). In one population historical and contemporary samples were remarkably genetically similar despite more than a decade of intense stocking. Estimation...... of admixture proportions showed a small genetic contribution from domesticated trout (approximately 6%), and individual admixture analysis demonstrated a majority of nonadmixed individuals. The expected genetic contribution by domesticated trout was 64%, assessed from the number of stocked trout and assuming...... in samples from a broodstock thought to represent the indigenous population and in a sample of wild spawners. Survival of domesticated trout and admixture with indigenous fish in the broodstock and subsequent stocking into the river, combined with a low population size of native trout relative to the number...

  2. Potential population and assemblage influences of non-native trout on native nongame fish in Nebraska headwater streams

    Science.gov (United States)

    Turek, Kelly C.; Pegg, Mark A.; Pope, Kevin L.; Schainost, Steve

    2014-01-01

    Non-native trout are currently stocked to support recreational fisheries in headwater streams throughout Nebraska. The influence of non-native trout introductions on native fish populations and their role in structuring fish assemblages in these systems is unknown. The objectives of this study were to determine (i) if the size structure or relative abundance of native fish differs in the presence and absence of non-native trout, (ii) if native fish-assemblage structure differs in the presence and absence of non-native trout and (iii) if native fish-assemblage structure differs across a gradient in abundances of non-native trout. Longnose dace Rhinichthys cataractae were larger in the presence of brown trout Salmo trutta and smaller in the presence of rainbow trout Oncorhynchus mykiss compared to sites without trout. There was also a greater proportion of larger white suckers Catostomus commersonii in the presence of brown trout. Creek chub Semotilus atromaculatus and fathead minnow Pimephales promelas size structures were similar in the presence and absence of trout. Relative abundances of longnose dace, white sucker, creek chub and fathead minnow were similar in the presence and absence of trout, but there was greater distinction in native fish-assemblage structure between sites with trout compared to sites without trout as trout abundances increased. These results suggest increased risk to native fish assemblages in sites with high abundances of trout. However, more research is needed to determine the role of non-native trout in structuring native fish assemblages in streams, and the mechanisms through which introduced trout may influence native fish populations.

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

    Science.gov (United States)

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

    2011-01-01

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

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

    OpenAIRE

    Cătălin Emilian Nistor; Ionuţ Bogdan Pagu; Emanuel Magdici; Benone Pasarin

    2014-01-01

    Study of morphological characters at fish by means of biometry is a frequently utilized method and consists in determining the variability of characters in groups of individuals, by direct measurement, weighting and statistical processing of obtained data. Effectuation of body measurements and weighting is used to determine the increase in length of fish and to evaluate the general physiological condition. Brook trout, rainbow trout, and brown trout were the object of the current study by...

  5. Molecular analysis of population genetic structure and recolonization of rainbow trout following the Cantara spill

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

    Walters, Jody P.; Downs, Christopher Charles

    2001-01-01

    Our 1999 objectives were to determine sources of rainbow trout Oncorhynchus mykiss and bull trout Salvelinus confluentus spawning and recruitment in the Idaho reach of the Kootenai River. We used a rotary-screw trap to capture juvenile trout to determine age at out-migration and to estimate total out-migration from the Boundary Creek drainage to the Kootenai River. The out-migrant estimate for March through August 1999 was 1,574 (95% C. I.= 825-3,283) juvenile rainbow trout. Most juveniles out-migrated at age-2 and age-3. No out-migrating bull trout were caught. Five of 17 rainbow trout radio-tagged in Idaho migrated upstream into Montana waters during the spawning season. Five bull trout originally radio-tagged in O'Brien Creek, Montana in early October moved downstream into Idaho and British Columbia by mid-October. Annual angler exploitation for the rainbow trout population upstream of Bonners Ferry, Idaho was estimated to be 58%. Multi-pass depletion estimates for index reaches of Caboose, Curley, and Debt creeks showed 0.20, 0.01, and 0.13 rainbow trout juveniles/m(sup 2), respectively. We estimated rainbow trout (180-415 mm TL) standing stock of 1.6 kg/ha for the Hemlock Bar reach (29.4 ha) of the Kootenai River, similar to the 1998 estimate. Recruitment of juvenile rainbow and bull trout from Idaho tributaries is not sufficient to be the sole source of subsequent older fish in the mainstem Kootenai River. These populations are at least partly dependent on recruitment from Montana waters. The low recruitment and high exploitation rate may be indicators of a rainbow trout population in danger of further decline

  7. OCCURRENCE OF INFECTIOUS PANCREATIC NECROSIS VIRUS (IPNV) IN FARMED RAINBOW TROUT (ONCHORHYNCHUS MYKISS) IN KOSOVO

    OpenAIRE

    Agim Rexhepi; Kristaq Berxholli; Peter Scheinert; Afrim Hamidi; Kurtesh Sherifi

    2013-01-01

    This article describes the research carried out for the detection of viruses responsible for VHS, IHN and IPN diseases in farmed rainbow trout (Oncorhynchus mykiss) in Kosovo for the three-year period between 2006 and 2008. Losses are often reported in trout fingerlings, but no virus has ever been isolated in the rainbow trout in Kosovo. A research project was carried out to determine the occurrence of VHSV, IHNV & IPNV from the samples of fish tissue and ovarian fluids from mature broodf...

  8. Experimental evaluation of rainbow trout Oncorhynchus mykiss predation on longnose dace Rhinichthys cataractae

    Science.gov (United States)

    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.

  9. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 2002 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Buettner, Edwin W.; Putnam, Scott A. [Idaho Department of Fish and Game

    2009-02-18

    This project monitored the daily passage of Chinook salmon Oncorhynchus tshawytscha, steelhead trout O. mykiss, and sockeye salmon smolts O. nerka during the 2002 spring out-migration at migrant traps on the Snake River and Salmon River. In 2002 fish management agencies released significant numbers of hatchery Chinook salmon and steelhead trout above Lower Granite Dam that were not marked with a fin clip or coded-wire tag. Generally, these fish were distinguishable from wild fish by the occurrence of fin erosion. Total annual hatchery Chinook salmon catch at the Snake River trap was 11.4 times greater in 2002 than in 2001. The wild Chinook catch was 15.5 times greater than the previous year. Hatchery steelhead trout catch was 2.9 times greater than in 2001. Wild steelhead trout catch was 2.8 times greater than the previous year. The Snake River trap collected 3,996 age-0 Chinook salmon of unknown rearing. During 2002, the Snake River trap captured 69 hatchery and 235 wild/natural sockeye salmon and 114 hatchery coho salmon O. kisutch. Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with flow. The significant increase in catch in 2002 was due to a 3.1 fold increase in hatchery Chinook production and a more normal spring runoff. Trap operations began on March 10 and were terminated on June 7. The trap was out of operation for a total of four days due to mechanical failure or debris. Hatchery Chinook salmon catch at the Salmon River trap was 4.2 times greater and wild Chinook salmon catch was 2.4 times greater than in 2001. The hatchery steelhead trout collection in 2002 was 81% of the 2001 numbers. Wild steelhead trout collection in 2002 was 81% of the previous year's catch. Trap operations began on March 10 and were terminated on May 29 due to high flows. The trap was out of operation for four days due to high flow or debris. The

  10. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 2003 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Buettner, Edwin W.; Putnam, Scott A. [Idaho Department of Fish and Game

    2009-02-18

    This project monitored the daily passage of Chinook salmon Oncorhynchus tshawytscha, steelhead trout O. mykiss, and sockeye salmon O. nerka smolts during the 2003 spring out-migration at migrant traps on the Snake River and Salmon River. In 2003 fish management agencies released significant numbers of hatchery Chinook salmon and steelhead trout above Lower Granite Dam that were not marked with a fin clip or coded-wire tag. Generally, these fish were distinguishable from wild fish by the occurrence of fin erosion. Total annual hatchery Chinook salmon catch at the Snake River trap was 2.1 times less in 2003 than in 2002. The wild Chinook catch was 1.1 times less than the previous year. Hatchery steelhead trout catch was 1.7 times less than in 2002. Wild steelhead trout catch was 2.1 times less than the previous year. The Snake River trap collected 579 age-0 Chinook salmon of unknown rearing. During 2003, the Snake River trap captured five hatchery and 13 wild/natural sockeye salmon and 36 coho salmon O. kisutch of unknown rearing. Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with flow. The significant differences in catch between 2003 and the previous year were due mainly to low flows during much of the trapping season and then very high flows at the end of the season, which terminated the trapping season 12 days earlier than in 2002. Trap operations began on March 9 and were terminated on May 27. The trap was out of operation for a total of zero days due to mechanical failure or debris. Hatchery Chinook salmon catch at the Salmon River trap was 16.8% less and wild Chinook salmon catch was 1.7 times greater than in 2002. The hatchery steelhead trout collection in 2003 was 5.6% less than in 2002. Wild steelhead trout collection was 19.2% less than the previous year. Trap operations began on March 9 and were terminated on May 24 due to high

  11. Smolt monitoring at the head of lower granite reservoir and lower Granite Dam, annual report 1999 operations.; ANNUAL

    International Nuclear Information System (INIS)

    United States. Bonneville Power Administration. Division of Fish and Wildlife; Idaho. Dept. of Fish and Game.

    2001-01-01

    This project monitored the daily passage of chinook salmon Oncorhynchus tshawytscha, steelhead trout O. mykiss, and sockeye salmon smolts O. nerka during the 1999 spring out-migration at migrant traps on the Snake River and Salmon River. All hatchery chinook salmon released above Lower Granite Dam were marked with a fin clip in 1999. Total annual hatchery chinook salmon catch at the Snake River trap was 440% of the 1998 number. The wild chinook catch was 603% of the previous year's catch. Hatchery steelhead trout catch was 93% of 1998 numbers. Wild steelhead trout catch was 68% of 1998 numbers. The Snake River trap collected 62 age-0 chinook salmon. During 1998 the Snake River trap captured 173 hatchery and 37 wild/natural sockeye salmon and 130 hatchery coho salmon O. kisutch. Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with high flows. Trap operations began on March 14 and were terminated for the season due to high flows on May 25. The trap was out of operation for 18 d during the season due to high flow and debris. Hatchery chinook salmon catch at the Salmon River trap was 214%, and wild chinook salmon catch was 384% of 1998 numbers. The hatchery steelhead trout collection in 1999 was 210% of the 1998 numbers. Wild steelhead trout collection in 1999 was 203% of the 1998 catch. Trap operations began on March 14 and were terminated for the season due to high flows on May 21. The trap was out of operation for 17 d during the season due to high flow and debris

  12. Smolt monitoring at the head of Lower Granite Reservoir and Lower Granite Dam, annual report 1997 operations.; ANNUAL

    International Nuclear Information System (INIS)

    United States. Bonneville Power Administration. Division of Fish and Wildlife.

    1999-01-01

    This project monitored the daily passage of chinook salmon Oncorhynchus tshawytscha and steelhead trout O. mykiss smolts during the 1997 spring out-migration at migrant traps on the Snake River and Salmon River. All hatchery chinook salmon released above Lower Granite Dam were marked with a fin clip in 1997. Total annual hatchery chinook salmon catch at the Snake River trap was 49% of the 1996 number but only 6% of the 1995 catch. The wild chinook catch was 77% of the 1996 but was only 13% of 1995. Hatchery steelhead trout catch was 18% of 1996 numbers but only 7% of the 1995 numbers. Wild steelhead trout catch was 22% of 1996 but only 11% of the 1995 numbers. The Snake River trap collected eight age-0 chinook salmon and one sockeye/kokanee salmon O. nerka. Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with high flows. Trap operations were terminated for the season due to high flows and trap damage on May 8 and were out of operation for 23 d due to high flow and debris. Hatchery chinook salmon catch at the Salmon River trap was 37% and wild chinook salmon catch was 60% of 1996 numbers but only 5% and 11% of 1995 catch, respectively. The 1997 hatchery steelhead trout collection was 13% of the 1996 catch and 32% of the 1995 numbers. Wild steelhead trout collection in 1997 was 21% of the 1996 catch and 13% of the 1995 numbers. Trap operations were terminated for the season due to high flows and trap damage on May 7 and were out of operation for 19 d due to high flow and debris

  13. Influence of a weak field of pulsed DC electricity on the behavior and incidence of injury in adult Steelhead and Pacific Lamprey

    Science.gov (United States)

    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.

  14. Influence of Didymosphenia geminata blooms on prey composition and associated diet and growth of Brown Trout

    Science.gov (United States)

    James, Daniel A.; Chipps, Steven R.

    2016-01-01

    We compared diet, stomach fullness, condition, and growth of Brown Trout Salmo trutta among streams with or without blooms of the benthic diatom Didymosphenia geminata in the Black Hills, South Dakota. In Rapid Creek, where D. geminata blooms covered ∼30% of the stream bottom, Brown Trout consumed fewer ephemeropterans (6–8% by weight) than individuals from two stream sections that have not had D. geminatablooms (Castle and Spearfish creeks; 13–39% by weight). In contrast, dipterans (primarily Chironomidae) represented a larger percentage of Brown Trout diets from Rapid Creek (D. geminata blooms present; 16–28% dry weight) compared with diets of trout from streams without D. geminata blooms (6–19% dry weight). Diets of small Brown Trout (100–199 mm TL) reflected the invertebrate species composition in benthic stream samples; in Rapid Creek, ephemeropterans were less abundant whereas dipterans were more abundant than in streams without D. geminata blooms. Stomach fullness and condition of Brown Trout from Rapid Creek were generally greater than those of Brown Trout from other populations. Linkages among invertebrate availability, diet composition, and condition of Brown Trout support the hypothesis that changes in invertebrate assemblages associated with D. geminata (i.e., more Chironomidae) could be contributing to high recruitment success for small Brown Trout in Rapid Creek.

  15. Cell-mediated cytotoxicity in rainbow trout, Oncorhynchus mykiss, infected with viral haemorrhagic septicaemia virus

    DEFF Research Database (Denmark)

    Utke, K.; Bergmann, S.; Lorenzen, Niels

    2007-01-01

    classical MHC class I locus Onmy-UBA is identical in the rainbow trout clone C25 and in the permanent rainbow trout cell line RTG-2. This enabled us to develop an assay to measure antiviral cytotoxicity in rainbow trout using a system of MHC class I-matched effector and target cells. Peripheral blood...... leucocytes (PBL) isolated from low dose viral haemorrhagic septicaemia virus (VHSV)-infected rainbow trout killed MHC class I-matched and later also xenogeneic MHC class I-mismatched VHSV-infected cells. When compared to PBL from uninfected control fish PBL from infected fish showed a higher transcriptional...

  16. Prebiotic Supplementation has Only Minimal Effects on Growth Efficiency, Intestinal Health and Disease Resistance of Westslope Cutthroat Trout Oncorhynchus clarkii lewisi Fed 30% Soybean Meal

    OpenAIRE

    Sealey, Wendy M.; Conley, Zachariah B.; Bensley, Molly

    2015-01-01

    Prebiotics have successfully been used to prevent infectious diseases in aquaculture and there is an increasing amount of literature that suggests that these products can also improve alternative protein utilization and digestion. Therefore, the objective of this study was to examine whether prebiotic supplementation increased the growth efficiency, intestinal health, and disease resistance of cutthroat trout fed a high level of dietary soybean meal. To achieve this objective, juvenile Westsl...

  17. Rainbow trout estrogen receptor (ER) competitive bindng and vitellogenin induction agonism/antagonism data for 94 chemicals

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset is from screening 94 diverse chemicals for estrogen receptor (ER) activation in a competitive rainbow trout ER binding assay and a trout liver slice...

  18. Temporary Restoration of Bull Trout Passage at Albeni Falls Dam

    Energy Technology Data Exchange (ETDEWEB)

    Paluch, Mark; Scholz, Allan; McLellan, Holly [Eastern Washington University Department of Biology; Olson, Jason [Kalispel Tribe of Indians Natural Resources Department

    2009-07-13

    This study was designed to monitor movements of bull trout that were provided passage above Albeni Falls Dam, Pend Oreille River. Electrofishing and angling were used to collect bull trout below the dam. Tissue samples were collected from each bull trout and sent to the U. S. Fish and Wildlife Service Abernathy Fish Technology Center Conservation Genetics Lab, Washington. The DNA extracted from tissue samples were compared to a catalog of bull trout population DNA from the Priest River drainage, Lake Pend Oreille tributaries, and the Clark Fork drainage to determine the most probable tributary of origin. A combined acoustic radio or radio tag was implanted in each fish prior to being transported and released above the dam. Bull trout relocated above the dam were able to volitionally migrate into their natal tributary, drop back downstream, or migrate upstream to the next dam. A combination of stationary radio receiving stations and tracking via aircraft, boat, and vehicle were used to monitor the movement of tagged fish to determine if the spawning tributary it selected matched the tributary assigned from the genetic analysis. Seven bull trout were captured during electrofishing surveys in 2008. Of these seven, four were tagged and relocated above the dam. Two were tagged and left below the dam as part of a study monitoring movements below the dam. One was immature and too small at the time of capture to implant a tracking tag. All four fish released above the dam passed by stationary receivers stations leading into Lake Pend Oreille and no fish dropped back below the dam. One of the radio tags was recovered in the tributary corresponding with the results of the genetic test. Another fish was located in the vicinity of its assigned tributary, which was impassable due to low water discharge at its mouth. Two fish have not been located since entering the lake. Of these fish, one was immature and not expected to enter its natal tributary in the fall of 2008. The other

  19. Effect