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Sample records for juvenile salmonid trawling

  1. Oceanographic Trawl Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  2. SWFSC FED Mid Water Trawl Juvenile Rockfish Survey, Surface Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — SWFSC FED Mid Water Trawl Juvenile Rockfish Survey: Station Information and Surface Data. Surveys have been conducted along the central California coast in May/June...

  3. SWFSC FED Mid Water Trawl Juvenile Rockfish Survey, CTD Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — SWFSC FED Mid Water Trawl Juvenile Rockfish Survey: CTD Data. Surveys have been conducted along the central California coast in May/June every year since 1983. In...

  4. Juvenile Salmonid Pathogen Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  5. Juvenile Salmonid IGF-I Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  6. Juvenile Salmonid Genetic Stock Identification Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  7. Juvenile Salmonid Trophic Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  8. Juvenile Salmonid Parasite Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  9. Juvenile Salmonid Otolith Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  10. Accurate aging of juvenile salmonids using fork lengths

    Science.gov (United States)

    Sethi, Suresh; Gerken, Jonathon; Ashline, Joshua

    2017-01-01

    Juvenile salmon life history strategies, survival, and habitat interactions may vary by age cohort. However, aging individual juvenile fish using scale reading is time consuming and can be error prone. Fork length data are routinely measured while sampling juvenile salmonids. We explore the performance of aging juvenile fish based solely on fork length data, using finite Gaussian mixture models to describe multimodal size distributions and estimate optimal age-discriminating length thresholds. Fork length-based ages are compared against a validation set of juvenile coho salmon, Oncorynchus kisutch, aged by scales. Results for juvenile coho salmon indicate greater than 95% accuracy can be achieved by aging fish using length thresholds estimated from mixture models. Highest accuracy is achieved when aged fish are compared to length thresholds generated from samples from the same drainage, time of year, and habitat type (lentic versus lotic), although relatively high aging accuracy can still be achieved when thresholds are extrapolated to fish from populations in different years or drainages. Fork length-based aging thresholds are applicable for taxa for which multiple age cohorts coexist sympatrically. Where applicable, the method of aging individual fish is relatively quick to implement and can avoid ager interpretation bias common in scale-based aging.

  11. Evaluation of Juvenile Salmonid Outmigration and Survival in the Lower Umatilla River Basin; 1996 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, Suzanne M.; Kern, J. Chris; Carmichael, Richard W. (Oregon Department of Fish and Wildlife, Portland, OR)

    1997-01-01

    This is the second year report of a multi-year project that monitors the outmigration and survival of hatchery and naturally-produced juvenile salmonids in the lower Umatilla River. This project supplements and complements ongoing or completed fisheries projects in the Umatilla River basin. Knowledge gained on outmigration and survival will assist researchers and managers in adapting hatchery practices, flow enhancement strategies, canal operations, and supplementation and enhancement efforts for natural and restored fish populations. The authors also report on tasks related to evaluating juvenile salmonid passage at Three Mile Falls Dam and West Extension Canal.

  12. Modeling Food Delivery Dynamics For Juvenile Salmonids Under Variable Flow Regimes

    Science.gov (United States)

    Harrison, L.; Utz, R.; Anderson, K.; Nisbet, R.

    2010-12-01

    Traditional approaches for assessing instream flow needs for salmonids have typically focused on the importance of physical habitat in determining fish habitat selection. This somewhat simplistic approach does not account for differences in food delivery rates to salmonids that arise due to spatial variability in river morphology, hydraulics and temporal variations in the flow regime. Explicitly linking how changes in the flow regime influences food delivery dynamics is an important step in advancing process-based bioenergetic models that seek to predict growth rates of salmonids across various life-stages. Here we investigate how food delivery rates for juvenile salmonids vary both spatially and with flow magnitude in a meandering reach of the Merced River, CA. We utilize a two-dimensional (2D) hydrodynamic model and discrete particle tracking algorithm to simulate invertebrate drift transport rates at baseflow and a near-bankfull discharge. Modeling results indicate that at baseflow, the maximum drift density occurs in the channel thalweg, while drift densities decrease towards the channel margins due to the process of organisms settling out of the drift. During high-flow events, typical of spring dam-releases, the invertebrate drift transport pathway follows a similar trajectory along the high velocity core and the drift concentrations are greatest in the channel centerline, though the zone of invertebrate transport occupies a greater fraction of the channel width. Based on invertebrate supply rates alone, feeding juvenile salmonids would be expected to be distributed down the channel centerline where the maximum predicted food delivery rates are located in this reach. However, flow velocities in these channel sections are beyond maximum sustainable swimming speeds for most juvenile salmonids. Our preliminary findings suggest that a lack of low velocity refuge may prevent juvenile salmonids from deriving energy from the areas with maximum drift density in this

  13. Avian Predation on Juvenile Salmonids in the Lower Columbia River: 1998 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Collis, Ken; Adamany, Stephanie; Roby, Daniel D.; Craig, David P.; Lyons, Donald E.

    2000-04-01

    The authors initiated a field study in 1997 to assess the impacts of fish-eating colonial waterbirds (i.e., terns, cormorants, and gulls) on the survival of juvenile salmonids in the lower Columbia River. Here the authors present results from the 1998 breeding season, the second field season of work on this project. The research objectives in 1998 were to: (1) determine the location, size, nesting chronology, nesting success, and population trajectories of breeding colonies of fish-eating birds in the lower Columbia River; (2) determine diet composition of fish-eating birds, including taxonomic composition and energy content of various prey types; (3) estimate forage fish consumption rates, with special emphasis on juvenile salmonids, by breeding adults and their young; (4) determine the relative vulnerability of different groups of juvenile salmonids to bird predation; (5) identify foraging range, foraging strategies, and habitat utilization by piscivorous waterbirds; and (6) test the feasibility of various alternative methods for managing avian predation on juvenile salmonids and develop recommendations to reduce avian predation, if warranted by the results.

  14. Avian Predation on Juvenile Salmonids in the Lower Columbia River: 1997 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Roby, Daniel D.; Craig, David P.; Collis, Ken; Adamany, Stephanie L.

    1998-09-01

    The authors initiated a field study in 1997 to assess the impacts of fish-eating colonial waterbirds (i.e., terns, cormorants, and gulls) on the survival of juvenile salmonids in the lower Columbia River. Here the authors present results from the 1998 breeding season, the second field season of work on this project. The research objectives in 1998 were to: (1) determine the location, size, nesting chronology, nesting success, and population trajectories of breeding colonies of fish-eating birds in the lower Columbia River; (2) determine diet composition of fish-eating birds, including taxonomic composition and energy content of various prey types; (3) estimate forage fish consumption rates, with special emphasis on juvenile salmonids, by breeding adults and their young; (4) determine the relative vulnerabilit2048 different groups of juvenile salmonids to bird predation; (5) identify foraging range, foraging strategies, and habitat utilization by piscivorous waterbirds; and (6) test the feasibility of various alternative methods for managing avian predation on juvenile salmonids and develop recommendations to reduce avian predation, if warranted by the results.

  15. Seasonal Juvenile Salmonid Presence and Migratory Behavior in the Lower Columbia River

    Energy Technology Data Exchange (ETDEWEB)

    Carter, Jessica A.; McMichael, Geoffrey A.; Welch, Ian D.; Harnish, Ryan A.; Bellgraph, Brian J.

    2009-04-30

    To facilitate preparing Biological Assessments of proposed channel maintenance projects, the Portland District of the U.S. Army Corps of Engineers contracted the Pacific Northwest National Laboratory to consolidate and synthesize available information about the use of the lower Columbia River and estuary by juvenile anadromous salmonids. The information to be synthesized included existing published documents as well as data from five years (2004-2008) of acoustic telemetry studies conducted in the Columbia River estuary using the Juvenile Salmon Acoustic Telemetry System. For this synthesis, the Columbia River estuary includes the section of the Columbia River from Bonneville Dam at river kilometer (Rkm) 235 downstream to the mouth where it enters the Pacific Ocean. In this report, we summarize the seasonal salmonid presence and migration patterns in the Columbia River estuary based on information from published studies as well as relevant data from acoustic telemetry studies conducted by NOAA Fisheries and the Pacific Northwest National Laboratory (PNNL) between 2004 and 2008. Recent acoustic telemetry studies, conducted using the Juvenile Salmon Acoustic Telemetry System (JSATS; developed by the Portland District of the U.S. Army Corps of Engineers), provided information on the migratory behavior of juvenile steelhead (O. mykiss) and Chinook salmon in the Columbia River from Bonneville Dam to the Pacific Ocean. In this report, Section 2 provides a summary of information from published literature on the seasonal presence and migratory behavior of juvenile salmonids in the Columbia River estuary and plume. Section 3 presents a detailed synthesis of juvenile Chinook salmon and steelhead migratory behavior based on use of the JSATS between 2004 and 2008. Section 4 provides a discussion of the information summarized in the report as well as information drawn from literature reviews on potential effects of channel maintenance activities to juvenile salmonids rearing in

  16. Acoustic Telemetry Evaluation of Juvenile Salmonid Passage and Survival at John Day Dam with Emphasis on the Prototype Surface Flow Outlet, 2008

    Energy Technology Data Exchange (ETDEWEB)

    Weiland, Mark A.; Ploskey, Gene R.; Hughes, James S.; Deng, Zhiqun; Fu, Tao; Monter, Tyrell J.; Johnson, Gary E.; Khan, Fenton; Wilberding, Matthew C.; Cushing, Aaron W.; Zimmerman, Shon A.; Faber, Derrek M.; Durham, Robin E.; Townsend, Richard L.; Skalski, John R.; Kim, Jina; Fischer, Eric S.; Meyer, Matthew M.

    2009-12-01

    The main purpose of the study was to evaluate the performance of Top Spill Weirs installed at two spillbays at John Day Dam and evaluate the effectiveness of these surface flow outlets at attracting juvenile salmon away from the powerhouse and reducing turbine passage. The Juvenile Salmonid Acoustic Telemetry System (JSATS) was used to estimate survival of juvenile salmonids passing the dam and also for calculating performance metrics used to evaluate the efficiency and effectiveness of the dam at passing juvenile salmonids.

  17. Juvenile Salmon Scale Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  18. Gas Bubble Trauma Monitoring and Research of Juvenile Salmonids, 1994-1995 Progress Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hans, Karen M.

    1997-07-01

    This report describes laboratory and field monitoring studies of gas bubble trauma (GBT) in migrating juvenile salmonids in the Snake and Columbia rivers. The first chapter describes laboratory studies of the progression of GBT signs leading to mortality and the use of the signs for GBT assessment. The progression and severity of GBT signs in juvenile salmonids exposed to different levels of total dissolved gas (TDG) and temperatures was assessed and quantified. Next, the prevalence, severity, and individual variation of GBT signs was evaluated to attempt to relate them to mortality. Finally, methods for gill examination in fish exposed to high TDG were developed and evaluated. Primary findings were: (1) no single sign of GBT was clearly correlated with mortality, but many GBT signs progressively worsened; (2) both prevalence and severity of GBT signs in several tissues is necessary; (3) bubbles in the lateral line were the earliest sign of GBT, showed progressive worsening, and had low individual variation but may develop poorly during chronic exposures; (4) fin bubbles had high prevalence, progressively worsened, and may be a persistent sign of GBT; and (5) gill bubbles appear to be the proximate cause of death but may only be relevant at high TDG levels and are difficult to examine. Chapter Two describes monitoring results of juvenile salmonids for signs of GBT. Emigrating fish were collected and examined for bubbles in fins and lateral lines. Preliminary findings were: (1) few fish had signs of GBT, but prevalence and severity appeared to increase as fish migrated downstream; (2) there was no apparent correlation between GBT signs in the fins, lateral line, or gills; (3) prevalence and severity of GBT was suggestive of long-term, non-lethal exposure to relatively low level gas supersaturated water; and (4) it appeared that GBT was not a threat to migrating juvenile salmonids. 24 refs., 26 figs., 3 tabs.

  19. Gas Bubble Disease Monitoring and Research of Juvenile Salmonids : Annual Report 1996.

    Energy Technology Data Exchange (ETDEWEB)

    Maule, Alec G.; Beeman, John W.; Hans, Karen M.; Mesa, M.G.; Haner, P.; Warren, J.J. [Geological Survey, Cook, WA (United States). Columbia River Research Lab.

    1997-10-01

    This document describes the project activities 1996--1997 contract year. This report is composed of three chapters which contain data and analyses of the three main elements of the project: field research to determine the vertical distribution of migrating juvenile salmonids, monitoring of juvenile migrants at dams on the Snake and Columbia rivers, and laboratory experiments to describe the progression of gas bubble disease signs leading to mortality. The major findings described in this report are: A miniature pressure-sensitive radio transmitter was found to be accurate and precise and, after compensation for water temperature, can be used to determine the depth of tagged-fish to within 0.32 m of the true depth (Chapter 1). Preliminary data from very few fish suggest that depth protects migrating juvenile steelhead from total dissolved gas supersaturation (Chapter 1). As in 1995, few fish had any signs of gas bubble disease, but it appeared that prevalence and severity increased as fish migrated downstream and in response to changing gas supersaturation (Chapter 2). It appeared to gas bubble disease was not a threat to migrating juvenile salmonids when total dissolved gas supersaturation was < 120% (Chapter 2). Laboratory studies suggest that external examinations are appropriate for determining the severity of gas bubble disease in juvenile salmonids (Chapter 3). The authors developed a new method for examining gill arches for intravascular bubbles by clamping the ventral aorta to reduce bleeding when arches were removed (Chapter 3). Despite an outbreak of bacterial kidney disease in the experimental fish, the data indicate that gas bubble disease is a progressive trauma that can be monitored (Chapter 3).

  20. Assessing Juvenile Salmonid Passage Through Culverts: Field Research in Support of Protocol Development

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Greg D.; Evans, Nathan R.; Pearson, Walter H.; Southard, John A.

    2001-10-30

    The primary goal of our research this spring/ summer was to refine techniques and examine scenarios under which a standardized protocol could be applied to assess juvenile coho salmon (O. kisutch) passage through road culverts. Field evaluations focused on capture-mark- recapture methods that allowed analysis of fish movement patterns, estimates of culvert passability, and potential identification of cues inducing these movements. At this stage, 0+ age coho salmon fry 30 mm to 65 mm long (fork length) were the species and age class of interest. Ultimately, the protocol will provide rapid, statistically rigorous methods for trained personnel to perform standardized biological assessments of culvert passability to a number of juvenile salmon species. Questions to be addressed by the research include the following: ? Do hydraulic structures such as culverts restrict habitat for juvenile salmonids? ? How do existing culverts and retrofits perform relative to juvenile salmonid passage? ? Do some culvert characteristics and hydraulic conditions provide better passage than others? ? Does the culvert represent a barrier to certain size classes of fish? Recommendations addressed issues of study site selection, initial capture, marking, recapture/observations, and estimating movement.

  1. Migratory Behavior and Survival of Juvenile Salmonids in the Lower Columbia River and Estuary in 2009

    Energy Technology Data Exchange (ETDEWEB)

    McMichael, Geoffrey A.; Harnish, Ryan A.; Bellgraph, Brian J.; Carter, Jessica A.; Ham, Kenneth D.; Titzler, P. Scott; Hughes, Michael S.

    2010-08-01

    The study reported herein was funded as part of the Anadromous Fish Evaluation Program, which is managed by the U.S. Army Corps of Engineers (USACE). The Anadromous Fish Evaluation Program study code is EST P 02 01: A Study of Salmonid Survival and Behavior through the Columbia River Estuary Using Acoustic Tags. The study was conducted by the Pacific Northwest National Laboratory (PNNL) and National Oceanic and Atmospheric Administration (NOAA) Fisheries for the USACE Portland District. Estimated survival of acoustic-tagged juvenile Chinook salmon and steelhead through the lower Columbia River and estuary in 2009 was lowest in the final 50 km of the estuary. Probability of survival was relatively high (>0.90) for yearling and subyearling Chinook salmon from the Bonneville Dam forebay (rkm 236) to Three-tree Point (rkm 49.6). Survival of juvenile Chinook salmon declined sharply through the lower 50 km of the estuary. Acoustic-tagged steelhead smolts did not survive as well as juvenile Chinook salmon between Bonneville Dam and the mouth of the Columbia River. Steelhead survival began to decline farther upstream (at rkm 86) relative to that of the Chinook salmon stocks. Subyearling Chinook salmon survival decreased markedly as the season progressed. It remains to be determined whether later migrating subyearling Chinook salmon are suffering increasing mortality as the season progresses or whether some portion of the apparent loss is due to fish extending their freshwater residence. This study provided the first glimpse into what promises to be a very informative way to learn more about how juvenile salmonid passage experiences through the FCRPS may influence their subsequent survival after passing Bonneville Dam. New information regarding the influence of migration pathway through the lower 50 km of the Columbia River estuary on probability of survival of juvenile salmonids, combined with increased understanding regarding the foraging distances and time periods of

  2. Physiological Assessment of Wild and Hatchery Juvenile Salmonids : Final Report, 2003.

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Donald A.; Beckman, Brian R.; Dickhoff, Walton W.

    2003-08-01

    It is generally held that hatchery-reared salmonids are of inferior quality and have lower smolt-to-adult survival compared to naturally-reared salmon. The overall objectives of the work performed under this contract were the following: (1) Characterize the physiology and development of naturally rearing juvenile salmonids to: (2) Allow for the design of effective rearing programs for producing wild-like smolts in supplementation and production hatchery programs. (3) Examine the relationship between growth rate and size on the physiology and migratory performance of fish reared in hatchery programs. (4) Examine the interaction of rearing temperature and feed rate on the growth and smoltification of salmon for use in producing a more wild-like smolt in hatchery programs.

  3. Effect of Multiple Turbine Passage on Juvenile Snake River Salmonid Survival

    Energy Technology Data Exchange (ETDEWEB)

    Ham, Kenneth D.; Anderson, James J.; Vucelick, Jessica A.

    2005-10-14

    This report describes a study conducted by Pacific Northwest National Laboratory to identify populations of migrating juvenile salmonids with a potential to be impacted by repeated exposure to turbine passage conditions. This study is part of a research program supported by the U.S. Department of Energy Wind/Hydropower Program. The program's goal is to increase hydropower generation and capacity while enhancing environmental performance. Our study objective is to determine whether the incremental effects of turbine passage during downstream migration impact populations of salmonids. When such a potential is found to exist, a secondary objective is to determine what level of effect of passing multiple turbines is required to decrease the number of successful migrants by 10%. This information will help identify whether future laboratory or field studies are feasible and design those studies to address conditions that present the greatest potential to improve dam survival and thus benefit fish and power generation.

  4. Smallmouth bass and largemouth bass predation on juvenile Chinook salmon and other salmonids in the Lake Washington basin

    Science.gov (United States)

    Tabor, R.A.; Footen, B.A.; Fresh, K.L.; Celedonia, M.T.; Mejia, F.; Low, D.L.; Park, L.

    2007-01-01

    We assessed the impact of predation by smallmouth bass Micropterus dolomieu and largemouth bass M. salmoides on juveniles of federally listed Chinook salmon Oncorhynchus tshawytscha and other anadromous salmonid populations in the Lake Washington system. Bass were collected with boat electrofishing equipment in the south end of Lake Washington (February-June) and the Lake Washington Ship Canal (LWSC; April-July), a narrow waterway that smolts must migrate through to reach the marine environment. Genetic analysis was used to identify ingested salmonids to obtain a more precise species-specific consumption estimate. Overall, we examined the stomachs of 783 smallmouth bass and 310 largemouth bass greater than 100 mm fork length (FL). Rates of predation on salmonids in the south end of Lake Washington were generally low for both black bass species. In the LWSC, juvenile salmonids made up a substantial part of bass diets; consumption of salmonids was lower for largemouth bass than for smallmouth bass. Smallmouth bass predation on juvenile salmonids was greatest in June, when salmonids made up approximately 50% of their diet. In the LWSC, overall black bass consumption of salmonids was approximately 36,000 (bioenergetics model) to 46,000 (meal turnover consumption model) juveniles, of which about one-third was juvenile Chinook salmon, one-third was coho salmon O. kisutch, and one-third was sockeye salmon O. nerka. We estimated that about 2,460,000 juvenile Chinook salmon (hatchery and wild sources combined) were produced in the Lake Washington basin in 1999; thus, the mortality estimates in the LWSC range from 0.5% (bioenergetics) to 0.6% (meal turnover). Black bass prey mostly on subyearlings of each salmonid species. The vulnerability of subyearlings to predation can be attributed to their relatively small size; their tendency to migrate when water temperatures exceed 15??C, coinciding with greater black bass activity; and their use of nearshore areas, where overlap

  5. Synthesis of Juvenile Salmonid Passage Studies at The Dalles Dam, Volume II, 2001-05

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Gary E.; Beeman, John W.; Duran, Ian; Puls, Andrew

    2007-08-15

    The overall goal of juvenile salmonid research at The Dalles Dam is to provide data to inform decisions on strategies to improve smolt survival rates at the project. Survival improvement strategies address the three primary passage routes at The Dalles Dam -- spillway, sluiceway, and turbines – with the general intent to increase spill and sluice passage and decrease turbine passage. Since the review by Ploskey et al. (2001a) of research during 1982-2000 at The Dalles Dam, the Corps funded over $20M of research in at least 39 studies during 2001-2006. The purpose of the current review is to synthesize juvenile salmonid passage data at The Dalles Dam (TDA) collected from 2001 through 2006. The data we synthesize comes from numerous research techniques employed to address particular study objectives at The Dalles Dam. The suite of techniques includes acoustic and radio telemetry, acoustic cameras, acoustic Doppler current profilers, balloon tags, computational fluid dynamics models, drogues, fixed and mobile hydroacoustics, fyke nets, physical scale models, PIT-tags, sensor fish, sonar trackers, and underwater video. Hydraulic data involves flow patterns and water velocities. Biological data involve forebay approach paths and residence times, horizontal and diel distributions, passage efficiencies and effectiveness, fish behaviors, tailrace egress and predation rates, and route-specific and total project survival rates. Data for 2001-2006 are synthesized in this report to provide, in conjunction with Ploskey et al. (2001a), resources for engineers, biologists, and dam operators to use when making decisions about fish protection measures for juvenile salmonids at The Dalles Dam. This review covers the major fish passage research efforts during 2001-2006 and includes sections on the Environmental Setting, Forebay and Project Passage Studies, Spill Studies, Sluiceway Studies, Turbine Studies, Smolt Survival Studies, and a Discussion.

  6. Habitat use by juvenile salmonids in Lake Ontario tributaries-species, age, diel and seasonal effects

    Science.gov (United States)

    Johnson, James H.; McKenna, James E.

    2017-01-01

    Understanding the habitat needs of fish and how these requirements may change seasonally over a 24-h period is important, especially for highly managed sport species. Consequently, we examined the diel and seasonal habitat use of four juvenile salmonid species in streams in the Lake Ontario watershed. For juvenile Atlantic salmon Salmo salarand juvenile rainbow trout Oncorhynchus mykiss, differences in day versus night habitat use were more profound than seasonal differences. Observed differences in day versus night habitat for all species and age classes were mainly due to the use of less object oriented cover at night and to a lesser extent to the use of slower velocities and smaller substrate at night. Seasonal differences in habitat use were also observed, likely due to increased fish size, and included movement to deeper and faster water and the use of larger substrate and more cover from summer to winter. Different habitat variables were important to individual species. Juvenile Atlantic salmon were associated with higher water velocities, juvenile rainbow trout with larger substrate and more cover, and subyearling Chinook salmon O. tshawytscha and subyearling coho salmon O. kisutch with small substrate and less cover. Our observations demonstrate that habitat partitioning occurs and likely reduces intraspecific and interspecific competition which may increase the potential production of all four species in sympatry. Consequently, these findings provide important information for resource managers charged with managing, protecting, and enhancing Great Lakes tributaries where all or some of these species occur.

  7. Progression and severity of gas bubble trauma in juvenile salmonids

    Science.gov (United States)

    Mesa, M.G.; Weiland, L.K.; Maule, A.G.

    2000-01-01

    We conducted laboratory experiments to assess the progression and to quantify the severity of signs of gas bubble trauma (GBT) in juvenile chinook salmon Oncorhynchus tshawytscha and steelhead Oncorhynchus mykiss exposed to different levels of total dissolved gas (TDG), and we attempted to relate these signs to the likelihood of mortality. When fish were exposed to 110% TDG for up to 22 d, no fish died, and there were few signs of GBT in the lateral line or gills. Bubbles in the fins, however, were relatively common, and they progressively worsened over the experimental period. When fish were exposed to 120% TDG for up to 140 h, chinook salmon had an LT20 (time necessary to kill 20% of the fish) ranging from 40 to 120 h, whereas steelhead had LT20s ranging from 20 to 35 h. In steelhead, bubbles in the lateral line, fins, and gills displayed poor trends of worsening over time, showed substantial interindividual variability, and were poorly related to mortality. In chinook salmon, only bubbles in the lateral line showed a distinct worsening over time, and the severity of bubbles in the lateral line was highly correlated with mortality. When fish were exposed to 130% TDG for up to 11 h, LT20s for chinook salmon ranged from 3 to 6 h, whereas those for steelhead ranged from 5 to 7 h. In chinook salmon, bubbles in the lateral line and fins, but not those in the gills, showed distinct trends of worsening over time. In steelhead, bubbles in the lateral line displayed the most significant trend of progressive severity. In both species at 130% TDG, the severity of all GBT signs was highly correlated with mortality. The progressive nature of GBT and the methods we developed to examine fish for GBT may be useful for monitoring programs that aim to assess the severity of dissolved gas supersaturation exposures experienced by fish in the wild. However, the efficacy of such programs seems substantially hindered by problems associated with (1) the variable persistence of GBT signs

  8. Juvenile salmonid monitoring in the White Salmon River, Washington, post-Condit Dam removal, 2016

    Science.gov (United States)

    Jezorek, Ian G.; Hardiman, Jill M.

    2017-06-23

    Condit Dam, at river kilometer 5.3 on the White Salmon River, Washington, was breached in 2011 and removed completely in 2012, allowing anadromous salmonids access to habitat that had been blocked for nearly 100 years. A multi-agency workgroup concluded that the preferred salmonid restoration alternative was natural recolonization with monitoring to assess efficacy, followed by a management evaluation 5 years after dam removal. Limited monitoring of salmon and steelhead spawning has occurred since 2011, but no monitoring of juveniles occurred until 2016. During 2016, we operated a rotary screw trap at river kilometer 2.3 (3 kilometers downstream of the former dam site) from late March through May and used backpack electrofishing during summer to assess juvenile salmonid distribution and abundance. The screw trap captured primarily steelhead (Oncorhynchus mykiss; smolts, parr, and fry) and coho salmon (O. kisutch; smolts and fry). We estimated the number of steelhead smolts at 3,851 (standard error = 1,454) and coho smolts at 1,093 (standard error = 412). In this document, we refer to O. mykiss caught at the screw trap as steelhead because they were actively migrating, but because we did not know migratory status of O. mykiss caught in electrofishing surveys, we simply refer to them as O. mykiss or steelhead/rainbow trout. Steelhead and coho smolts tagged with passive integrated transponder tags were subsequently detected downstream at Bonneville Dam on the Columbia River. Few Chinook salmon (O. tshawytscha) fry were captured, possibly as a result of trap location or effects of a December 2015 flood. Sampling in Mill, Buck, and Rattlesnake Creeks (all upstream of the former dam site) showed that juvenile coho were present in Mill and Buck Creeks, suggesting spawning had occurred there. We compared O. mykiss abundance data in sites on Buck and Rattlesnake Creeks to pre-dam removal data. During 2016, age-0 O. mykiss were more abundant in Buck Creek than in 2009 or

  9. Migratory Behavior and Survival of Juvenile Salmonids in the Lower Columbia River, Estuary, and Plume in 2010

    Energy Technology Data Exchange (ETDEWEB)

    McMichael, Geoffrey A.; Harnish, Ryan A.; Skalski, John R.; Deters, Katherine A.; Ham, Kenneth D.; Townsend, Richard L.; Titzler, P. Scott; Hughes, Michael S.; Kim, Jin A.; Trott, Donna M.

    2011-09-01

    Uncertainty regarding the migratory behavior and survival of juvenile salmonids passing through the lower Columbia River and estuary after negotiating dams on the Federal Columbia River Power System (FCRPS) prompted the development and application of the Juvenile Salmon Acoustic Telemetry System (JSATS). The JSATS has been used to investigate the survival of juvenile salmonid smolts between Bonneville Dam (river kilometer (rkm) 236) and the mouth of the Columbia River annually since 2004. In 2010, a total of 12,214 juvenile salmonids were implanted with both a passive integrated transponder (PIT) and a JSATS acoustic transmitter. Using detection information from JSATS receiver arrays deployed on dams and in the river, estuary, and plume, the survival probability of yearling Chinook salmon and steelhead smolts tagged at John Day Dam was estimated form multiple reaches between rkm 153 and 8.3 during the spring. During summer, the survival probability of subyearling Chinook salmon was estimated for the same reaches. In addition, the influence of routes of passage (e.g., surface spill, deep spill, turbine, juvenile bypass system) through the lower three dams on the Columbia River (John Day, The Dalles, and Bonneville) on juvenile salmonid smolt survival probability from the dams to rkm 153 and then between rkm 153 and 8.3 was examined to increase understanding of the immediate and latent effects of dam passage on juvenile salmon survival. Similar to previous findings, survival probability was relatively high (>0.95) for most groups of juvenile salmonids from the Bonneville Dam tailrace to about rkm 50. Downstream of rkm 50 the survival probability of all species and run types we examined decreased markedly. Steelhead smolts suffered the highest mortality in this lower portion of the Columbia River estuary, with only an estimated 60% of the tagged fish surviving to the mouth of the river. In contrast, yearling and subyearling Chinook salmon smolts survived to the mouth

  10. Survival Estimates for the Passage of Spring-Migrating Juvenile Salmonids through Snake and Columbia River Dams and Reservoirs, 2008.

    Energy Technology Data Exchange (ETDEWEB)

    Faulkner, James R.; Smith, Steven G.; Muir, William D. [Northwest Fisheries Science Center

    2009-06-23

    In 2008, the National Marine Fisheries Service completed the sixteenth year of a study to estimate survival and travel time of juvenile salmonids Oncorhynchus spp. passing through dams and reservoirs on the Snake and Columbia Rivers. All estimates were derived from detections of fish tagged with passive integrated transponder (PIT) tags. We PIT tagged and released a total of 18,565 hatchery steelhead O. mykiss, 15,991 wild steelhead, and 9,714 wild yearling Chinook salmon O. tshawytscha at Lower Granite Dam in the Snake River. In addition, we utilized fish PIT tagged by other agencies at traps and hatcheries upstream from the hydropower system and at sites within the hydropower system in both the Snake and Columbia Rivers. These included 122,061 yearling Chinook salmon tagged at Lower Granite Dam for evaluation of latent mortality related to passage through Snake River dams. PIT-tagged smolts were detected at interrogation facilities at Lower Granite, Little Goose, Lower Monumental, Ice Harbor, McNary, John Day, and Bonneville Dams and in the PIT-tag detector trawl operated in the Columbia River estuary. Survival estimates were calculated using a statistical model for tag-recapture data from single release groups (the single-release model). Primary research objectives in 2008 were to: (1) estimate reach survival and travel time in the Snake and Columbia Rivers throughout the migration period of yearling Chinook salmon and steelhead, (2) evaluate relationships between survival estimates and migration conditions, and (3) evaluate the survival estimation models under prevailing conditions. This report provides reach survival and travel time estimates for 2008 for PIT-tagged yearling Chinook salmon (hatchery and wild), hatchery sockeye salmon O. nerka, hatchery coho salmon O. kisutch, and steelhead (hatchery and wild) in the Snake and Columbia Rivers. Additional details on the methodology and statistical models used are provided in previous reports cited here. Survival

  11. Comparative Performance of Acoustic-tagged and PIT-tagged Juvenile Salmonids

    Energy Technology Data Exchange (ETDEWEB)

    Hockersmith, Eric E.; Brown, Richard S.; Liedtke, Theresa L.

    2008-02-01

    Numerous research tools and technologies are currently being used to evaluate fish passage and survival to determine the impacts of the Federal Columbia River Power System (FCRPS) on endangered and threatened juvenile salmonids, including PIT tags, balloon tags, hydroacoustic evaluations, radio telemetry, and acoustic telemetry. Each has advantages and disadvantages, but options are restricted in some situations because of limited capabilities of a specific technology, lack of detection capability downstream, or availability of adequate numbers of fish. However, there remains concern about the comparative effects of the tag or the tagging procedure on fish performance. The recently developed Juvenile Salmonid Acoustic Telemetry System (JSATS) acoustic transmitter is the smallest active acoustic tag currently available. The goal of this study was to determine whether fish tagged with the JSATS acoustic-telemetry tag can provide unbiased estimates of passage behavior and survival within the performance life of the tag. We conducted both field and laboratory studies to assess tag effects. For the field evaluation we released a total of 996 acoustic-tagged fish in conjunction with 21,026 PIT-tagged fish into the tailrace of Lower Granite Dam on 6 and 13 May. Travel times between release and downstream dams were not significantly different for the majority of the reaches between acoustic-tagged and PIT-tagged fish. In addition to the field evaluation, a series of laboratory experiments were conducted to determine if growth and survival of juvenile Chinook salmon surgically implanted with acoustic transmitters is different than untagged or PIT tagged juvenile Chinook salmon. Only yearling fish with integrated and non-integrated transmitters experienced mortalities, and these were low (<4.5%). Mortality among sub-yearling control and PIT-tag treatments ranged up to 7.7% while integrated and non-integrated treatments had slightly higher rates (up to 8.3% and 7

  12. Turbulence Investigation and Reproduction for Assisting Downstream Migrating Juvenile Salmonids, Part I of II, 2001-2002 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hotchkiss, Rollin H. (Washington State University, Department of Civil and Environmental Engineers, Albrook Hydraulics Laboratory)

    2002-12-01

    Turbulence in gravel bed rivers plays a critical role in most stream processes including contaminant and nutrient transport, aquatic habitat selection, and natural channel design. While most hydraulic designs and fluid models are based on bulk velocity, migrating juvenile salmon experience and react to the temporally varied turbulent fluctuations. Without properly understanding and accounting for the continuous turbulent motions proper fishway design and guidance are impossible. Matching temporally varied flow to fish reactions is the key to guiding juvenile salmonids to safe passageways. While the ideal solution to fish guidance design would be to use specific fluid action-fish reaction mechanisms, such concrete cause and effect relations have not been established. One way to approach the problem of guidance is to hypothesize that in an environment lacking obvious bulk flow cues (like the reservoir environment), turbulent flow conditions similar to those experienced by juvenile salmonids in natural migration corridors will be attractive to juvenile salmonids. Proof of this hypothesis requires three steps: (1) gathering data on turbulence characteristics in natural migration corridors, (2) reproduction of the turbulence parameters in a controlled environment, and (3) testing the reproduced turbulence on actively migrating juvenile salmonids for increased passage efficiencies. The results from the third step have not been finalized, therefore this report will focus on understanding turbulent processes in gravel bed rivers and reproduction of turbulence in controlled environments for use in fish passage technologies. The purposes of this report are to (1) present data collected in natural gravel bed rivers, (2) present a simple method for reproduction of appropriate turbulence levels in a controlled environment, (3) compare these results to those from one prototype surface collector (PSC), and (4) discuss the implications on fish passage design.

  13. Hydroacoustic Evaluation of Juvenile Salmonid Passage and Distribution at Lookout Point Dam, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Fenton; Johnson, Gary E.; Royer, Ida M.; Hughes, James S.; Fischer, Eric S.; Trott, Donna M.; Ploskey, Gene R.

    2011-07-01

    This report presents the results of an evaluation of juvenile salmonid passage and distribution at Lookout Point Dam (LOP) on the Middle Fork Willamette River. The study was conducted by the Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers, Portland District (USACE). The goal of the study was to provide fish passage and distribution data to support decisions on long-term measures to enhance downstream passage at LOP and others dams in USACE’s Willamette Valley Project in response to the listing of Upper Willamette River Spring Chinook salmon (Oncorhynchus tshawytscha) and Upper Willamette River steelhead (O. mykiss) as threatened under the Endangered Species Act. During the year-long study period - February 1, 2010 to January 31, 2011the objectives of the hydroacoustic evaluation of fish passage and distribution at LOP were to: 1. Estimate passage rates, run timing, horizontal distribution, and diel distribution at turbine penstock intakes for smolt-size fish. 2. Estimate passage rates, run timing and diel distribution at turbine penstock intakes for small-size fish. 3. Estimate passage rates and run timing at the regulating outlets for smolt-size fish. 4. Estimate vertical distribution of smolt-size fish in the forebay near the upstream face of the dam. The fixed-location hydroacoustic technique was used to accomplish the objectives of this study. Transducers (420 kHz) were deployed in each penstock intake, above each RO entrance, and on the dam face; a total of nine transducers (2 single-beam and 7 split-beam) were used. We summarize the findings from the hydroacoustic evaluation of juvenile salmonid passage and distribution at LOP during February 2010 through January 2011 as follows. • Fish passage rates for smolt-size fish (> ~90 mm) were highest during December-January and lowest in mid-summer through early fall. • During the entire study period, an estimated total of 142,463 fish ± 4,444 (95% confidence interval) smolt

  14. Hydroacoustic Evaluation of Juvenile Salmonid Passage at The Dalles Dam Sluiceway, 2005

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Gary E.; Khan, Fenton; Hedgepeth, J; Mueller, Robert P.; Rakowski, Cynthia L.; Richmond, Marshall C.; Serkowski, John A.; Skalski, John R.

    2006-06-01

    The U.S. Army Corps of Engineers Portland District engaged the Pacific Northwest National Laboratory to evaluate fish passage at The Dalles Dam powerhouse in 2005. The goal of the study was to provide information on smolt passage that will inform decisions on long-term measures and operations to enhance sluiceway passage and reduce turbine passage to improve smolt survival at the dam. The study addressed one of the main programs dedicated to improving juvenile salmonid survival at The Dalles Dam: Surface Flow Bypass. The study objectives (see below) were met using a combination of hydroacoustic and hydraulic data. The study incorporated fixed-location hydroacoustic methods across the entire powerhouse, with especially intense sampling using multiple split-beam transducers at all sluiceway portals. We did not sample fish passage at the spillway in 2005. In the sluiceway nearfield, we used an acoustic camera to track fish movements. The fish data were interpreted with hydraulic data from a computational fluid dynamics (CFD) model. Fish passage data were collected in the framework of an “experiment” using a randomized block design (3-day treatments; two treatments) to compare two sluiceway operational configurations: Sluice 2+5 and Sluice 2+19 (six gates open for each configuration). Total project outflow was 76% of the 10-year average for spring and 71% of the 10-year average for summer. Based on these findings, we make the following recommendations: 1) The sluice should be operated 24 h/d from April until November. 2) Open six rather than three sluice gates to take advantage of the maximum hydraulic capacity of the sluiceway. 3) Open the three gates above the western-most operating main turbine unit and the three gates at MU 8 where turbine passage rates are relatively high. 4) Operate the turbine units below open sluice gates as a standard fish operations procedure. 5) Develop hydraulic and entrance enhancements to the sluiceway to tap the potential of The

  15. A standard operating procedure for the surgical implantation of transmitters in juvenile salmonids

    Science.gov (United States)

    Liedtke, T.L.; Beeman, J.W.; Gee, L.P.

    2012-01-01

    Biotelemetry is a useful tool to monitor the movements of animals and is widely applied in fisheries research. Radio or acoustic technology can be used, depending on the study design and the environmental conditions in the study area. A broad definition of telemetry also includes the use of Passive Integrated Transponder (PIT) tags, either separately or with a radio or acoustic transmitter. To use telemetry, fish must be equipped with a transmitter. Although there are several attachment procedures available, surgical implantation of transmitters in the abdominal cavity is recognized as the best technique for long-term telemetry studies in general (Stasko and Pincock, 1977; Winter, 1996; Jepsen, 2003), and specifically for juvenile salmonids, Oncorhynchus spp. (Adams and others, 1998a, 1998b; Martinelli and others, 1998; Hall and others, 2009). Studies that use telemetry assume that the processes by which the animals are captured, handled, and tagged, as well as the act of carrying the transmitter, will have minimal effect on their behavior and performance. This assumption, commonly stated as a lack of transmitter effects, must be valid if telemetry studies are to describe accurately the movements and behavior of an entire population of interest, rather than the subset of that population that carries transmitters. This document describes a standard operating procedure (SOP) for surgical implantation of radio or acoustic transmitters in juvenile salmonids. The procedures were developed from a broad base of published information, laboratory experiments, and practical experience in tagging thousands of fish for numerous studies of juvenile salmon movements near Columbia River and Snake River hydroelectric dams. Staff from the Western Fisheries Research Center's Columbia River Research Laboratory (CRRL) frequently have used telemetry studies to evaluate new structures or operations at hydroelectric dams in the Columbia River Basin, and these evaluations typically

  16. Significance of Selective Predation and Development of Prey Protection Measures for Juvenile Salmonids in the Columbia and Snake River Reservoirs: Annual Progress Report, February 1993-February 1994.

    Energy Technology Data Exchange (ETDEWEB)

    Poe, Thomas P.

    1994-08-01

    This report addresses the problem of predator-prey interactions of juvenile salmonids in the Columbia and Snake River. Six papers are included on selective predation and prey protection. Attention is focused on monitoring the movements, the distribution, and the behavior of juvenile chinook salmon and northern squawfish.

  17. Evaluation of juvenile salmonid behavior near a prototype weir box at Cowlitz Falls Dam, Washington, 2013

    Science.gov (United States)

    Kock, Tobias J.; Liedtke, Theresa L.; Ekstrom, Brian K.; Tomka, Ryan G.; Rondorf, Dennis W.

    2014-01-01

    Collection of juvenile salmonids at Cowlitz Falls Dam is a critical part of the effort to restore salmon in the upper Cowlitz River because the majority of fish that are not collected at the dam pass downstream and enter a large reservoir where they become landlocked and lost to the anadromous fish population. However, the juvenile fish collection system at Cowlitz Falls Dam has failed to achieve annual collection goals since it first began operating in 1996. Since that time, numerous modifications to the fish collection system have been made and several prototype collection structures have been developed and tested, but these efforts have not substantially increased juvenile fish collection. Studies have shown that juvenile steelhead (Oncorhynchus mykiss), coho salmon (Oncorhynchus kisutch), and Chinook salmon (Oncorhynchus tshawytscha) tend to locate the collection entrances effectively, but many of these fish are not collected and eventually pass the dam through turbines or spillways. Tacoma Power developed a prototype weir box in 2009 to increase capture rates of juvenile salmonids at the collection entrances, and this device proved to be successful at retaining those fish that entered the weir. However, because of safety concerns at the dam, the weir box could not be deployed near a spillway gate where the prototype was tested, so the device was altered and re-deployed at a different location, where it was evaluated during 2013. The U.S. Geological Survey conducted an evaluation using radiotelemetry to monitor fish behavior near the weir box and collection flumes. The evaluation was conducted during April–June 2013. Juvenile steelhead and coho salmon (45 per species) were tagged with a radio transmitter and passive integrated transponder (PIT) tag, and released upstream of the dam. All tagged fish moved downstream and entered the forebay of Cowlitz Falls Dam. Median travel times from the release site to the forebay were 0.8 d for steelhead and 1.2 d for coho

  18. Hydroacoustic Evaluation of Juvenile Salmonid Passage and Distribution at Lookout Point Dam, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Fenton; Johnson, Gary E.; Royer, Ida M.; Hughes, James S.; Fischer, Eric S.; Trott, Donna M.; Ploskey, Gene R.

    2012-05-31

    Pacific Northwest National Laboratory evaluated juvenile salmonid passage and distribution at Lookout Point Dam (LOP) on the Middle Fork Willamette River for the U.S. Army Corps of Engineers, Portland District (USACE), to provide data to support decisions on long-term measures to enhance downstream passage at LOP and others dams in USACE's Willamette Valley Project. This study was conducted in response to the listing of Upper Willamette River Spring Chinook salmon (Oncorhynchus tshawytscha) and Upper Willamette River steelhead (O. mykiss) as threatened under the Endangered Species Act. We conducted a hydroacoustic evaluation of juvenile salmonid passage and distribution at LOP during February 2010 through January 2011. Findings from this 1 year of study should be applied carefully because annual variation can be expected due to variability in adult salmon escapement, egg-to-fry and fry-to-smolt survival rates, reservoir rearing and predation, dam operations, and weather. Fish passage rates for smolt-size fish (> {approx}90 mm and < 300 mm) were highest during December-January and lowest in mid-summer through early fall. Passage peaks were also evident in early spring, early summer, and late fall. During the entire study period, an estimated total of 142,463 fish {+-} 4,444 (95% confidence interval) smolt-size fish passed through turbine penstock intakes. Of this total, 84% passed during December-January. Run timing for small-size fish ({approx}65-90 mm) peaked (702 fish) on December 18. Diel periodicity of smolt-size fish showing crepuscular peaks was evident in fish passage into turbine penstock intakes. Relatively few fish passed into the Regulating Outlets (ROs) when they were open in summer (2 fish/d) and winter (8 fish/d). Overall, when the ROs were open, RO efficiency (RO passage divided by total project passage) was 0.004. In linear regression analyses, daily fish passage (turbines and ROs combined) for smolt-size fish was significantly related to

  19. Hydroacoustic Evaluation of Juvenile Salmonid Passage at The Dalles Dam in 2004

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Gary E.; Hanks, Michael E.; Khan, Fenton; Cook, Chris B.; Hedgepeth, J; Mueller, Robert P.; Rakowski, Cynthia L.; Richmond, Marshall C.; Sargeant, Susan L.; Serkowski, John A.; Skalski, John R.

    2005-06-01

    The U.S. Army Corps of Engineers Portland District engaged the Pacific Northwest National Laboratory to evaluate juvenile salmon passage at The Dalles Dam in 2004 to inform decisions about long-term measures and operations to enhance sluiceway and spill passage and reduce turbine passage to improve smolt survival at the dam. PNNL used fixed-location hydroacoustic sampling across the entire project, especially at the sluiceway and spillway, using multiple split-beam transducers at selected locations. At the sluiceway nearfield, we used an acoustic camera to track fish. The fish data were interpreted and integrated with hydraulic data from a CFD model and in-field ADCP measurements. Two sluiceway operations were compared: West only (SL 1) vs. West+East (SL 1 + SL 18). Based on our findings, we concluded that The Dalles Dam sluiceway has the potential to be highly efficient and effective at passing juvenile salmonids. This potential could be tapped with hydraulic and entrance enhancements to the sluiceway. We recommended the following: (1) six rather than three sluice gates should be opened to take advantage of the maximum hydraulic capacity of the sluiceway. (2) The turbine units below open sluice gates should be operated as a standard fish operations procedure. (3) In 2005, the Corps and fisheries agencies should consider operating sluice gates in one or more of the following combinations of six gates: (a) SL 1-1, 1-2, 1-3 and SL 18-1, 18-2, 18-3 (repeat 2004 operation), (b) SL 1-1, 1-2, 1-3 and SL 11-1, 11-2, 11-3, or (c) SL 1-1, 1-2, 1-3 and SL 2-1, 2-2, 2-3. The following elements for surface flow bypasses which should be considered during design of any sluiceway enhancements at The Dalles Dam: (1) form an extensive surface flow bypass flow net (surface bypass discharge greater than {approx}7% of total project discharge), (2) create a gradual increase in water velocity approaching the surface flow bypass (ideally, acceleration < 1 m/s/m), (3) make water

  20. System-Wide Significance of Predation on Juvenile Salmonids in Columbia and Snake River Reservoirs : Annual Report 1992.

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, James H.; Poe, Thomas P.

    1993-12-01

    Northern squawfish (Ptychocheilus oregonensis) predation on juvenile salmonids was characterized during 1992 at ten locations in the Columbia River below Bonneville Dam and at three locations in John Day Reservoir. During the spring and summer, 1,487 northern squawfish were collected in the lower Columbia River and 202 squawfish were sampled in John Day Reservoir. Gut content data, predator weight, and water temperature were used to compute a consumption index (CI) for northern squawfish, and overall diet was also described. In the Columbia River below Bonneville Dam, northern squawfish diet was primarily fish (spring 69%; summer 53%), most of which were salmonids. Salmonids were also the primary diet component in the Bonneville Dam tailrace, John Day Dam forebay, and the McNary Dam tailrace. Crustaceans were the dominant diet item at the John Day mid-reservoir location, although sample sizes were small. About half of the non-salmonid preyfish were sculpins. The consumption index (CI) of northern squawfish was generally higher during summer than during spring. The highest CI`s were observed during summer in the tailrace boat restricted zones of Bonneville Dam (CI = 7.8) and McNary Dam (CI = 4.6). At locations below Bonneville Dam, CI`s were relatively low near Covert`s Landing and Rooster Rock, higher at four locations between Blue Lake and St. Helens, and low again at three downriver sites (Kalama, Ranier, and Jones Beach). Northern squawfish catches and CI`s were noticeably higher throughout the lower Columbia compared to mid-reservoir sites further upriver sampled during 1990--92. Predation may be especially intense in the free-flowing section of the Columbia River below Bonneville Dam. Smallmouth bass (Micropterus dolomieui; N = 198) ate mostly fish -- 25% salmonids, 29% sculpins, and 46% other fish. Highest catches of smallmouth bass were in the John Day Dam forebay.

  1. Survival Estimates for the Passage of Spring-Migrating Juvenile Salmonids through Snake and Columbia River Dams and Reservoirs, 2001-2002 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Zabel, Richard; Williams, John G.; Smith, Steven G. (Northwest and Alaska Fisheries Science Center, Fish Ecology Division, Seattle, WA)

    2002-06-01

    In 2001, the National Marine Fisheries Service and the University of Washington completed the ninth year of a study to estimate survival and travel time of juvenile salmonids (Oncorhynchus spp.) passing through dams and reservoirs on the Snake and Columbia Rivers. All estimates were derived from passive integrated transponder (PIT)-tagged fish. We PIT tagged and released at Lower Granite Dam a total of 17,028 hatchery and 3,550 wild steelhead. In addition, we utilized fish PIT tagged by other agencies at traps and hatcheries upstream of the hydropower system and sites within the hydropower system. PIT-tagged smolts were detected at interrogation facilities at Lower Granite, Little Goose, Lower Monumental, McNary, John Day, and Bonneville Dams and in the PIT-tag detector trawl operated in the Columbia River estuary. Survival estimates were calculated using the Single-Release Model. Primary research objectives in 2001 were to: (1) estimate reach and project survival and travel time in the Snake and Columbia Rivers throughout the yearling chinook salmon and steelhead migrations; (2) evaluate relationships between survival estimates and migration conditions; and (3) evaluate the survival-estimation models under prevailing conditions. This report provides reach survival and travel time estimates for 2001 for PIT-tagged yearling chinook salmon and steelhead (hatchery and wild) in the Snake and Columbia Rivers. Results are reported primarily in the form of tables and figures with a minimum of text. More details on methodology and statistical models used are provided in previous reports cited in the text. Results for summer-migrating chinook salmon will be reported separately.

  2. Survival Estimates for the Passage of Juvenile Salmonids through Snake and Columbia River Dams and Reservoirs, 2002-2003 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Muir, William D.; Smith, Steven G.; Zabel, Richard W. (NOAA Fisheries, Northwest Fisheries Center, Seattle, WA)

    2003-07-01

    In 2002, the National Marine Fisheries Service and the University of Washington completed the tenth year of a study to estimate survival and travel time of juvenile salmonids (Oncorhynchus spp.) passing through dams and reservoirs on the Snake and Columbia Rivers. All estimates were derived from detections of fish tagged with passive integrated transponder tags (PIT tags). We PIT tagged and released a total of 19,891 hatchery steelhead at Lower Granite Dam. In addition, we utilized fish PIT tagged by other agencies at traps and hatcheries upstream from the hydropower system and sites within the hydropower system. PIT-tagged smolts were detected at interrogation facilities at Lower Granite, Little Goose, Lower Monumental, McNary, John Day, and Bonneville Dams and in the PIT-tag detector trawl operated in the Columbia River estuary. Survival estimates were calculated using a statistical model for tag-recapture data from single release groups (the ''Single-Release Model''). Primary research objectives in 2002 were to (1) estimate reach and project survival and travel time in the Snake and Columbia Rivers throughout the migration period of yearling chinook salmon O. tshawytscha and steelhead O. mykiss; (2) evaluate relationships between survival estimates and migration conditions; and (3) evaluate the survival-estimation models under prevailing conditions. This report provides reach survival and travel time estimates for 2002 for PIT-tagged yearling chinook salmon (hatchery and wild), hatchery sockeye salmon O. nerka, hatchery coho salmon O. kisutch, and steelhead (hatchery and wild) in the Snake and Columbia Rivers. Results are reported primarily in the form of tables and figures; details on methodology and statistical models used are provided in previous reports cited here. Results for summer-migrating chinook salmon will be reported separately.

  3. Survival Estimates for the Passage of Spring-Migrating Juvenile Salmonids through Snake and Columbia River Dams and Reservoirs, 2005-2006 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Steven G.; Muir, William D.; Marsh, Douglas M. (National Marine Fisheries Service, Northwest Fisheries Science Center, Fish Ecology Division, Seattle, WA)

    2006-05-01

    In 2005, the National Marine Fisheries Service and the University of Washington completed the thirteenth year of a study to estimate survival and travel time of juvenile salmonids Oncorhynchus spp. passing through dams and reservoirs on the Snake and Columbia Rivers. All estimates were derived from detections of fish tagged with passive integrated transponder tags (PIT tags). We PIT tagged and released a total of 18,439 hatchery steelhead, 5,315 wild steelhead, and 6,964 wild yearling Chinook salmon at Lower Granite Dam in the Snake River. In addition, we utilized fish PIT tagged by other agencies at traps and hatcheries upstream from the hydropower system and at sites within the hydropower system in both the Snake and Columbia Rivers. PIT-tagged smolts were detected at interrogation facilities at Lower Granite, Little Goose, Lower Monumental, Ice Harbor, McNary, John Day, and Bonneville Dams and in the PIT-tag detector trawl operated in the Columbia River estuary. Survival estimates were calculated using a statistical model for tag-recapture data from single release groups (the ''single-release model''). Primary research objectives in 2005 were: (1) Estimate reach survival and travel time in the Snake and Columbia Rivers throughout the migration period of yearling Chinook salmon O. tshawytscha and steelhead O. mykiss. (2) Evaluate relationships between survival estimates and migration conditions. (3) Evaluate the survival estimation models under prevailing conditions. This report provides reach survival and travel time estimates for 2005 for PIT-tagged yearling Chinook salmon (hatchery and wild), hatchery sockeye salmon O. nerka, hatchery coho salmon O. kisutch, and steelhead (hatchery and wild) in the Snake and Columbia Rivers. Additional details on the methodology and statistical models used are provided in previous reports cited here.

  4. Hydroacoustic Evaluation of Juvenile Salmonid Passage and Distribution at Detroit Dam, 2011

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Fenton; Royer, Ida M.; Johnson, Gary E.; Ham, Kenneth D.

    2012-11-15

    Pacific Northwest National Laboratory evaluated juvenile salmonid passage and distribution at Detroit Dam (DET) on the North Santiam River, Oregon for the U.S. Army Corps of Engineers (USACE) to provide data to support decisions on long-term measures to enhance downstream passage at DET and others dams in USACE’s Willamette Valley Project. This study was conducted in response to regulatory requirements necessitated by the listing of Upper Willamette River Spring Chinook salmon (Oncorhynchus tshawytscha) and Upper Willamette River steelhead (O. mykiss) as threatened under the Endangered Species Act. The goal of the study was to provide information of juvenile salmonid passage and distribution at DET from February 2011 through February 2012. The results of the hydroacoustic study provide new and, in some cases, first-ever data on passage estimates, run timing, distributions, and relationships between fish passage and environmental variables at the dam. This information will inform management decisions on the design and development of surface passage and collection devices to help restore Chinook salmon populations in the North Santiam River watershed above DET. During the entire study period, an estimated total of 182,526 smolt-size fish (±4,660 fish, 95% CI) passed through turbine penstock intakes. Run timing peaked in winter and early spring months. Passage rates were highest during late fall, winter and early spring months and low during summer. Horizontal distribution for hours when both turbine units were operated simultaneously indicated Unit 2 passed almost twice as much fish as Unit 1. Diel distribution for smolt-size fish during the study period was fairly uniform, indicating fish were passing the turbines at all times of the day. A total of 5,083 smolt-size fish (± 312 fish, 95% CI) were estimated passed via the spillway when it was open between June 23 and September 27, 2011. Daily passage was low at the spillway during the June-August period, and

  5. Hydroacoustic Evaluation of Juvenile Salmonid Passage at The Dalles Dam Spillway, 2006

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Gary E.; Khan, Fenton; Skalski, John R.; Rakowski, Cynthia L.; Richmond, Marshall C.; Serkowski, John A.

    2007-05-24

    The objective of this study was to determine detailed vertical, horizontal, intensive, and diel distributions of juvenile salmonid passage at the spillway at The Dalles Dam from April 12 to July16, 2006. These data are being applied in the Spillway Improvements Program to position release pipes for direct injury and mortality studies and to provide baseline data for assessment of the vortex suppression devices scheduled for deployment in 2007. We estimated fish distributions from hydroacoustic data collected with split-beam transducers arrayed across Bays 1 through 9 and 14. Spill at ~20 kcfs per bay was bulked at Bays 1-6, although the other bays were opened at times during the study to maintain a 40% spill percentage out of total project discharge. The vertical distribution of fish was skewed toward the surface during spring, but during summer, passage peaked at 2-3 m above the spillway ogee. Fish passage rates (number per hour) and fish densities (number per kcfs) were highest at Bay 6, followed by passage at Bay 5. This result comports with spillway horizontal distribution data from radio telemetry and hydroacoustic studies in 2004. The vertical and horizontal distribution of fish passage at bays 5 and 6 was much more variable during spring than summer and more variable at bay 5 than bay 6. Diel distribution data revealed that fish passage was highest during 0600-0700 h in spring; otherwise passage was reasonably uniform on a diel basis. This study substantiates the purpose of the spillway vortex suppression device to re-distribute downstream migrants away from Bay 6 toward Bays 1-5.

  6. Effect of multiple turbine passage on juvenile Snake River salmonid survival

    Energy Technology Data Exchange (ETDEWEB)

    Ham, K. D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Anderson, J. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Vucellck, J. A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2005-09-01

    Juvenile salmonids originating in the Snake River upstream of Lower Granite Dam must pass up to eight hydroelectric projects during their downstream migration to the Pacific Ocean. Fish may pass a project through a turbine or a spillbay or be screened into a bypass system that either collects fish into a barge or releases them downstream of the project. Previous reviews of studies of downstream passage for salmon at hydroelectric projects in the Columbia River basin found higher mean mortality at turbines than for spillways or bypass systems. The potential mechanisms of mortality during turbine passage may include pressure changes, cavitation, shear, turbulence, strike, or grinding. Observing those mechanisms is challenging in the field, but laboratory studies have demonstrated that a single exposure to shear or pressure changes similar to turbine passage conditions can result in injury for some individuals. Because fish pass several dams along their migration, individuals experience a series of passage events. If estimates of surviving the passage of a single project are applied to each passage event, then the underlying assumption is that the mortality at each project is independent of previous exposure. If individuals approaching a project were already sub-lethally stressed, higher than expected mortality rates might occur upon subsequent passage events. Report presents the hypothesis that fish passing more than one turbine will experience a greater than expected rate of mortality. Because measuring an incremental increase in mortality would be challenging in the field, scientists developed an approach to first assess whether such an increment has any potential to influence a fish population. This approach identified populations at risk and will help design laboratory or field experiments to address those risks.

  7. Comparative evaluation of molecular diagnostic tests for Nucleospora salmonis and prevalence in migrating juvenile salmonids from the Snake River, USA

    Science.gov (United States)

    Badil, Samantha; Elliott, Diane G.; Kurobe, Tomofumi; Hedrick, Ronald P.; Clemens, Kathy; Blair, Marilyn; Purcell, Maureen K.

    2011-01-01

    Nucleospora salmonis is an intranuclear microsporidian that primarily infects lymphoblast cells and contributes to chronic lymphoblastosis and a leukemia-like condition in a range of salmonid species. The primary goal of this study was to evaluate the prevalence of N. salmonis in out-migrating juvenile hatchery and wild Chinook salmon Oncorhynchus tshawytscha and steelhead O. mykiss from the Snake River in the U.S. Pacific Northwest. To achieve this goal, we first addressed the following concerns about current molecular diagnostic tests for N. salmonis: (1) nonspecific amplification patterns by the published nested polymerase chain reaction (nPCR) test, (2) incomplete validation of the published quantitative PCR (qPCR) test, and (3) whether N. salmonis can be detected reliably from nonlethal samples. Here, we present an optimized nPCR protocol that eliminates nonspecific amplification. During validation of the published qPCR test, our laboratory developed a second qPCR test that targeted a different gene sequence and used different probe chemistry for comparison purposes. We simultaneously evaluated the two different qPCR tests for N. salmonis and found that both assays were highly specific, sensitive, and repeatable. The nPCR and qPCR tests had good overall concordance when DNA samples derived from both apparently healthy and clinically diseased hatchery rainbow trout were tested. Finally, we demonstrated that gill snips were a suitable tissue for nonlethal detection of N. salmonis DNA in juvenile salmonids. Monitoring of juvenile salmonid fish in the Snake River over a 3-year period revealed low prevalence of N. salmonis in hatchery and wild Chinook salmon and wild steelhead but significantly higher prevalence in hatchery-derived steelhead. Routine monitoring of N. salmonis is not performed for all hatchery steelhead populations. At present, the possible contribution of this pathogen to delayed mortality of steelhead has not been determined.

  8. Determine the Influence of Time Held in “Knockdown” Anesthesia on Survival and Stress of Surgically Implanted Juvenile Salmonids

    Energy Technology Data Exchange (ETDEWEB)

    Woodley, Christa M.; Wagner, Katie A.; Knox, Kasey M.

    2012-01-31

    The Juvenile Salmon Acoustic Telemetry System (JSATS) was developed for the U.S. Army Corp of Engineers Portland District (USACE) to address questions related to survival and performance measures of juvenile salmonids as they pass through the Federal Columbia River Power System (FCRPS). Researchers using JSATS acoustic transmitters (ATs) were tasked with standardizing the surgical implantation procedure to ensure that the stressors of handling and surgery on salmonids were consistent and less likely to cause effects of tagging in survival studies. Researchers questioned whether the exposure time in 'knockdown' anesthesia (or induction) to prepare fish for surgery could influence the survival of study fish (CBSPSC 2011). Currently, fish are held in knockdown anesthesia after they reach Stage 4 anesthesia until the completion of the surgical implantation of a transmitter, varies from 5 to 15 minutes for studies conducted in the Columbia Basin. The Columbia Basin Surgical Protocol Steering Committee (CBSPSC ) expressed concern that its currently recommended 10-minute maximum time limit during which fish are held in anesthetic - tricaine methanesulfonate (MS-222, 80 mg L-1 water) - could increase behavioral and physiological costs, and/or decrease survival of outmigrating juvenile salmonids. In addition, the variability in the time fish are held at Stage 4 could affect the data intended for direct comparison of fish within or among survival studies. Under the current recommended protocol, if fish exceed the 10-minute time limit, they are to be released without surgical implantation, thereby increasing the number of fish handled and endangered species 'take' at the bypass systems for FCRPS survival studies.

  9. Evaluation of Juvenile Salmonid Outmigration and Survival in the Lower Umatilla River Basin, Annual Report 1999-2000.

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, Suzanne M.; Carmichael, Richard W.; Ehlers, Danette L.

    2002-04-01

    This is the sixth annual report of a multi-year project that monitors the outmigration and survival of hatchery and natural juvenile salmonids in the lower Umatilla River. This project supplements and complements ongoing or completed fisheries projects in the Umatilla River basin. Knowledge gained on outmigration and survival assists researchers and managers in adapting hatchery practices, flow enhancement strategies, canal and fish ladder operations, and supplementation and enhancement efforts for natural and restored fish populations. Findings from this study also measure the success of upriver habitat improvement projects and provide an overall evaluation of the Umatilla River fisheries restoration program.

  10. Survival Estimates for the Passage of Juvenile Salmonids through Snake River Dams and Reservoirs, 1994 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Muir, William D.

    1995-02-01

    In 1994, the National Marine Fisheries Service and the University of Washington completed the second year of a multi-year study to estimate survival of juvenile salmonids (Oncorhynchus spp.) passing through the dams and reservoirs of the Snake River. Actively migrating smolts were collected at selected locations above, at, and below Lower Granite Dam, tagged with passive integrated transponder (PIT) tags, and released to continue their downstream migration. Survival estimates were calculated using the Single-Release, Modified Single-Release, and Paired-Release Models.

  11. Development of a new multiple sampling trawl with autonomous opening/closing net control system for sampling juvenile pelagic fish

    Science.gov (United States)

    Oozeki, Yoshioki; Hu, Fuxiang; Tomatsu, Chiaki; Kubota, Hiroshi

    2012-03-01

    A new multiple layer sampling trawl with an autonomous net opening/closing control system was developed to sample pelagic juvenile fish quantitatively. The new trawl system, based on the Matsuda-Oozeki-Hu Trawl (MOHT), has a rigid-frame 3.3 m high and 2.35 m wide and five nets of 11.0 m length with a rectangular mouth of 2.22 m×1.81 m (4 m2 mouth area; large-scale prototype). A cambered V-shape depressor is hung below the frame and two bridles are attached at the midpoint of the side frames. A net-release controller is used, which not only controls the net release mechanism but also records the net depth, temperature and flow rate during net towing. The controller sends stored command signals to the net release mechanism as depth settings and/or time settings and does not require any commands from the surface through a conducting cable or by acoustic signals. Two other models were constructed before the construction of the large-scale prototype, which are a small-scale prototype (2 m2 mouth area) for testing the net release mechanism and a 1/4-scale model of the large-scale prototype for flume tank tests. Flume tank tests with the 1/4-scale model showed that the frame leaned forward at a tilt angle from 5 to 15 degrees at towing speeds from 0.8 to 1.4 m s-1. Opened nets closed smoothly and sequentially nets were completely opened when the trigger was released by the command. Net depth rarely changed even during changes in towing speed. Sea trials both by the small-scale and the large-scale prototype demonstrated the same towing characteristics expected from the flume tank tests. The newly developed multiple layer opening/closing MOHT (MOC-MOHT) is considered to be suitable for quantitative layer sampling of juvenile fish.

  12. Factors influencing the survival of outmigrating juvenile salmonids through multiple dam passages: an individual-based approach.

    Science.gov (United States)

    Elder, Timothy; Woodley, Christa M; Weiland, Mark A; Strecker, Angela L

    2016-08-01

    Substantial declines of Pacific salmon populations have occurred over the past several decades related to large-scale anthropogenic and climatic changes in freshwater and marine environments. In the Columbia River Basin, migrating juvenile salmonids may pass as many as eight large-scale hydropower projects before reaching the ocean; however, the cumulative effects of multiple dam passages are largely unknown. Using acoustic transmitters and an extensive system of hydrophone arrays in the Lower Columbia River, we calculated the survival of yearling Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) passing one, two, or three dams. We applied a unique index of biological characteristics and environmental exposures, experienced by each fish individually as it migrated downstream, in order to examine which factors most influence salmonid survival. High outflow volumes led to involuntary spill in 2011 and created an environment of supersaturated dissolved gas concentrations. In this environment, migrating smolt survival was strongly influenced by barometric pressure, fish velocity, and water temperature. The effect of these variables on survival was compounded by multiple dam passages compared to fish passing a single dam. Despite spatial isolation between dams in the Lower Columbia River hydrosystem, migrating smolt appear to experience cumulative effects akin to a press disturbance. In general, Chinook salmon and steelhead respond similarly in terms of survival rates and responses to altered environmental conditions. Management actions that limit dissolved gas concentrations in years of high flow will benefit migrating salmonids at this life stage.

  13. Turbulence Investigation and Reproduction for Assisting Downstream Migrating Juvenile Salmonids, Part II of II; Effects of Induced Turbulence on Behavior of Juvenile Salmon, 2001-2005 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Perry, Russell W.; Farley, M. Jared; Hansen, Gabriel S. (US Geological Survey, Western Fisheries Research Center, Columbia River Research Laboratory, Cook, WA)

    2005-07-01

    Passage through dams is a major source of mortality of anadromous juvenile salmonids because some populations must negotiate up to eight dams in Columbia and Snake rivers. Dams cause direct mortality when fish pass through turbines, but dams may also cause indirect mortality by altering migration conditions in rivers. Forebays immediately upstream of dams have decreased the water velocity of rivers and may contribute substantially to the total migration delay of juvenile salmonids. Recently, Coutant (2001a) suggested that in addition to low water velocities, lack of natural turbulence may contribute to migration delay by causing fish to lose directional cues. Coutant (2001a) further hypothesized that restoring turbulence in dam forebays may reduce migration delay by providing directional cues that allow fish to find passage routes more quickly (Coutant 2001a). Although field experiments have yielded proof of the concept of using induced turbulence to guide fish to safe passage routes, little is known about mechanisms actually causing behavioral changes. To test hypotheses about how turbulence influences movement and behavior of migrating juvenile salmonids, we conducted two types of controlled experiments at Cowlitz Falls Dam, Washington. A common measure of migration delay is the elapsed time between arrival at, and passage through, a dam. Therefore, for the first set of experiments, we tested the effect of induced turbulence on the elapsed time needed for fish to traverse through a raceway and pass over a weir at its downstream end (time trial experiment). If turbulence helps guide fish to passage routes, then fish should pass through the raceway quicker in the presence of appropriately scaled and directed turbulent cues. Second, little is known about how the physical properties of water movement provide directional cues to migrating juvenile salmonids. To examine the feasibility of guiding fish with turbulence, we tested whether directed turbulence could guide

  14. Turbulence investigation and reproduction for assisting downstream migrating juvenile salmonids, Part II of II: Effects of induced turbulence on behavior of juvenile salmon, 2001-2005 final report

    Science.gov (United States)

    Perry, R.; Farley , M.; Hansen, G.; Morse , J.; Rondorf, D.

    2005-01-01

    Passage through dams is a major source of mortality of anadromous juvenile salmonids because some populations must negotiate up to eight dams in Columbia and Snake rivers. Dams cause direct mortality when fish pass through turbines, but dams may also cause indirect mortality by altering migration conditions in rivers. Forebays immediately upstream of dams have decreased the water velocity of rivers and may contribute substantially to the total migration delay of juvenile salmonids. Recently, Coutant (2001a) suggested that in addition to low water velocities, lack of natural turbulence may contribute to migration delay by causing fish to lose directional cues. Coutant (2001a) further hypothesized that restoring turbulence in dam forebays may reduce migration delay by providing directional cues that allow fish to find passage routes more quickly (Coutant 2001a). Although field experiments have yielded proof of the concept of using induced turbulence to guide fish to safe passage routes, little is known about mechanisms actually causing behavioral changes. To test hypotheses about how turbulence influences movement and behavior of migrating juvenile salmonids, we conducted two types of controlled experiments at Cowlitz Falls Dam, Washington. A common measure of migration delay is the elapsed time between arrival at, and passage through, a dam. Therefore, for the first set of experiments, we tested the effect of induced turbulence on the elapsed time needed for fish to traverse through a raceway and pass over a weir at its downstream end (time trial experiment). If turbulence helps guide fish to passage routes, then fish should pass through the raceway quicker in the presence of appropriately scaled and directed turbulent cues. Second, little is known about how the physical properties of water movement provide directional cues to migrating juvenile salmonids. To examine the feasibility of guiding fish with turbulence, we tested whether directed turbulence could guide

  15. Quantifying the effect of predators on endangered species using a bioenergetics approach : Caspian terns and juvenile salmonids in the Columbia River estuary

    NARCIS (Netherlands)

    Roby, DD; Lyons, DE; Craig, DP; Collis, K; Visser, GH

    2003-01-01

    We estimated the consumption of juvenile salmonids (Oncorhynchus spp.) and other forage fishes by Caspian terns (Sterna caspia) nesting on Rice Island in the Columbia River estuary in 1997 and 1998 using a bioenergetics modeling approach. The study was prompted by concern that Caspian tern predation

  16. Evaluation of Juvenile Salmonid Outmigration and Survival in the Lower Umatilla River Basin, Annual Report 2000-2001.

    Energy Technology Data Exchange (ETDEWEB)

    White, Tara C.; Jewett, Shannon M.; Hanson, Josh T.

    2003-04-11

    This is the seventh year of a multi-year project, monitoring the outmigration and survival of juvenile salmonids in the lower Umatilla River. This project both supplements and complements ongoing and completed work within the Umatilla River basin. Knowledge gained on juvenile outmigration and survival assists researchers and managers in adapting hatchery practices, flow enhancement strategies, canal and fish ladder operations, and supplementation and enhancement efforts of natural and restored fish populations. Findings from this study also measure the success of upriver habitat improvement projects and provide an overall evaluation of the Umatilla River fisheries restoration program. The general objectives for 2001 were to: (1) Estimate migrant abundance and survival and determine migration parameters of PIT-tagged hatchery and natural juvenile salmonids; (2) Monitor natural production and estimate overall abundance of pacific lamprey, chinook and coho salmon and summer steelhead; (3) Assess the condition and health of migrants and determine length-frequency distributions through time; (4) Investigate the effects of canal and fishway operations and environmental conditions on fish migration and survival; (5) Investigate and implement improved tag monitoring capabilities; and (6) Participate in planning and coordination activities within the basin and disseminate results. More specifically, 2001 objectives included the ongoing evaluation of migrant abundance and survival of tagged hatchery fish groups from various species-specific hatchery, rearing, acclimation and release strategies; fourth year reach survival results; continuation of transport evaluation studies; outmigrant monitoring and estimation of natural abundance, and further investigation of the effects of canal operations, environmental factors, fish condition and health on migration, abundance and survival. Some of the key findings for 2001 are: (1) A significant decline in outmigrant abundance of

  17. Survival Estimates for the Passage of Juvenile Salmonids through Snake River Dams and Reservoirs, 1997 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hockersmith, Eric E.

    1999-03-01

    This report consists of two parts describing research activities completed during 1997 under Bonneville Power Administration Project Number 93-29. Part 1 provides reach survival and travel time estimates for 1997 for PIT-tagged hatchery steelhead and yearling chinook salmon in the Snake and Columbia Rivers. The results are reported primarily in the form of tables and figures with a minimum of text. More detailed information on methodology and the statistical models used in the analysis are provided in previous annual reports cited in the text. Analysis of the relationships among travel time, survival, and environmental factors for 1997 and previous years of the study will be reported elsewhere. Part 2 of this report describes research to determine areas of loss and delay for juvenile hatchery salmonids above Lower Granite Reservoir.

  18. Evaluation of Juvenile Salmonid Outmigration and Survival in the Lower Umatilla River Basin, Annual Report 2003-2006.

    Energy Technology Data Exchange (ETDEWEB)

    White, Tara

    2007-02-01

    This report summarizes activities conducted by the Oregon Department of Fish and Wildlife's Juvenile Outmigration and Survival M&E project in the Umatilla River subbasin between 2004-2006. Information is used to make informed decisions on hatchery effectiveness, natural production success, passage improvement and flow enhancement strategies. Data collected includes annual estimates of smolt abundance, migration timing, and survival, life history characteristics and productivity status and trends for spring and fall Chinook salmon, coho salmon and summer steelhead. Productivity data provided is the key subbasin scale measure of the effectiveness of salmon and steelhead restoration actions in the Umatilla River. Information is also used for regional planning and recovery efforts of Mid-Columbia River (MCR) ESA-listed summer steelhead. Monitoring is conducted via smolt trapping and PIT-tag interrogation at Three Mile Falls Dam. The Umatilla Juvenile Outmigration and Survival Project was established in 1994 to evaluate the success of management actions and fisheries restoration efforts in the Umatilla River Basin. Project objectives for the 2004-2006 period were to: (1) operate the PIT tag detection system at Three Mile Falls Dam (TMFD), (2) enhance provisional PIT-tag interrogation equipment at the east bank adult fish ladder, (3) monitor the migration timing, abundance and survival of naturally-produced juvenile salmonids and trends in natural production, (4) determine migration parameters and survival of hatchery-produced fish representing various rearing, acclimation and release strategies, (5) evaluate the relative survival between transported and non-transported fish, (6) monitor juvenile life history characteristics and evaluate trends over time, (7) investigate the effects of river, canal, fishway operations and environmental conditions on smolt migration and survival, (8) document the temporal distribution and diversity of resident fish species, and (9

  19. Survival Estimates for the Passage of Juvenile Salmonids through Snake River Dams and Reservoirs, 1996 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Steven G.

    1998-02-01

    In 1996, the National Marine Fisheries Service and the University of Washington completed the fourth year of a multi-year study to estimate survival of juvenile salmonids (Oncorhynchus spp.) passing through dams and reservoirs on the Snake River. Actively migrating smolts were collected near the head of Lower Granite Reservoir and at Lower Granite Dam, tagged with passive integrated transponder (PIT) tags, and released to continue their downstream migration. Individual smolts were subsequently detected at PIT-tag detection facilities at Lower Granite, Little Goose, Lower Monumental, McNary, John Day and Bonneville Dams. Survival estimates were calculated using the Single-Release (SR) and Paired-Release (PR) Models. Timing of releases of tagged hatchery steelhead (O. mykiss) from the head of Lower Granite Reservoir and yearling chinook salmon (O. tshawytscha) from Lower Granite Dam in 1996 spanned the major portion of their juvenile migrations. Specific research objectives in 1996 were to (1) estimate reach and project survival in the Snake River using the Single-Release and Paired-Release Models throughout the yearling chinook salmon and steelhead migrations, (2) evaluate the performance of the survival-estimation models under prevailing operational and environmental conditions in the Snake River, and (3) synthesize results from the 4 years of the study to investigate relationships between survival probabilities, travel times, and environmental factors such as flow levels and water temperature.

  20. Evaluation of Juvenile Salmonid Outmigration and Survival in the Lower Umatilla River Basin, Annual Report 2001-2002.

    Energy Technology Data Exchange (ETDEWEB)

    White, Tara C.; Hanson, Josh T.; Jewett, Shannon M.

    2004-01-01

    The year of 2002 represented the eighth year of a multi-year project, monitoring the outmigration and survival of juvenile salmonids in the lower Umatilla River. This project both supplements and complements various ongoing and completed work within the Umatilla River basin. Knowledge gained on juvenile outmigration and survival assists researchers and managers in adapting hatchery practices, flow enhancement strategies, canal and fish ladder operations, and supplementation and enhancement efforts of natural and restored fish populations. Findings from this study also assist in assessment of the success of upriver habitat improvement projects and provide an overall evaluation of the Umatilla River fisheries restoration program. General project objectives include: Evaluation of the outmigration and survival of natural and hatchery juvenile salmonids in the lower Umatilla River, in an effort to enhance the understanding of migration characteristics, survival bottlenecks, species interactions and effects of management strategies. Specific objectives for 2002 included: (1) Operation of the remote interrogation system at Three Mile Falls Dam, West Extension Canal; (2) Design of improved PIT tag detection capabilities at Three Mile Falls Dam east bank adult fish ladder; (3) Estimates of migrant abundance, migration timing and in-basin survival of tagged juvenile salmonids representing various hatchery, rearing, acclimation and release strategies; (4) Monitoring of abundance and trends in natural production of salmon, steelhead and pacific lamprey; (5) Continuation of transport evaluation studies to evaluate the relative survival between transported and nontransported fish; (6) Assessment of the condition, health, size, growth and smolt status of hatchery and natural migrants; (7) Investigation of the effects of canal and fishway operations and environmental conditions on fish migration and survival; (8) Documentation of temporal distribution and diversity of resident

  1. System-Wide Significance of Predation on Juvenile Salmonids in the Columbia and Snake River Reservoirs : Annual Report of Research 1991.

    Energy Technology Data Exchange (ETDEWEB)

    Shively, R.S.

    1991-01-01

    We indexed consumption rates of northern squawfish (Ptychoch oregonensis) preying upon juvenile salmonids in four lower Snake River reservoirs. Stomach contents were also collected from smallmouth bass (Micropterus dolomieui), channel catfish (Ictaluris gunctatus), and walleye (Stizostedion vitreum). Northern squawfish digestive tracts were analyzed and the overall diet (% weight) was dominated by fish and crustaceans. Examination of stomach contents smallmouth bass showed that crustaceans (primarily crayfish) dominated their diets. Overall, the consumption rate of juvenile salmonids by smallmouth bass was low. The northern squawfish consumption index (CI) at Snake River locations ranged from zero at all mid-reservoir locations to 1.2 at Lower Granite forebay. In John Day Reservoir, CI values ranged from 0.5 to 1.9 in May and from 0.9 to 3.0 in July. Consumption index values were highest in forebay and tailrace areas, and were slightly higher in BRZs than in non-restricted zones.

  2. Enumeration of Juvenile Salmonids in the Okanogan Basin Using Rotary Screw Traps, Performance Period: March 15, 2006 - July 15, 2006.

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Peter N.; Rayton, Michael D.

    2007-05-01

    The Colville Tribes identified the need for collecting baseline census data on the timing and abundance of juvenile salmonids in the Okanogan River basin for the purpose of documenting local fish populations, augmenting existing fishery data and assessing natural production trends of salmonids. This report documents and assesses the pilot year of rotary trap capture of salmonid smolts on the Okanogan River. The project is a component of the Colville Tribes Okanogan Basin Monitoring and Evaluation Program (OBMEP) which began in 2004. Trapping for outmigrating fish began on 14 March 2006 and continued through 11 July 2006. Anadromous forms of Oncorhynchus, including summer steelhead (O. mykiss), Chinook (O. tshawytscha), and sockeye (O. nerka), were targeted for this study; all have verified, natural production in the Okanogan basin. Both 8-ft and 5-ft rotary screw traps were deployed on the Okanogan River from the Highway 20 Bridge and typically fished during evening hours or 24 hours per day, depending upon trap position and discharge conditions. Juvenile Chinook salmon were the most abundant species trapped in 2006 (10,682 fry and 2,024 smolts), followed by sockeye (205 parr and 3,291 smolts) and steelhead (1 fry and 333 smolts). Of the trapped Chinook, all fry were wild origin and all but five of the smolts were hatchery-reared. All trapped sockeye were wild origin and 88% of the steelhead smolts were hatchery-reared. Mark-recapture experiments were conducted using Chinook fry and hatchery-reared steelhead smolts (sockeye were not used in 2006 because the peak of the juvenile migration occurred prior to the onset of the mark-recapture experiments). A total of 930 chinook fry were marked and released across eight separate release dates (numbers of marked Chinook fry released per day ranged from 34 to 290 fish). A total of 11 chinook fry were recaptured for an overall trap efficiency of 1.18%. A total of 710 hatchery-reared steelhead were marked and released across

  3. Magnitude and Dynamics of Predation on Juvenile Salmonids in Columbia and Snake River Reservoirs, Annual Report of Research, 1989-1990.

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, J.H.

    1990-07-01

    Three aspects of predation upon juvenile salmonids in the Columbia River are addressed in this report: (1) Indexing predator consumption. During 1989--1990, two indices of northern squawfish consumption upon juvenile salmonids were developed for use throughout the Columbia River Basin. The direct Consumption Index (CI) is based upon the concept of meal turnover time and takes into account number of salmonids, temperature, total gut content weight and predator weight. A Bioenergetics Index (BI) for consumption indexing was also developed to complement the direct CI. In the BI, growth, consumption, excretion/evacuation and respiration processes are modeled to predict the consumption required to produce an observed growth increment. (2) Studies on predator-smolt dynamics. Northern squawfish consumption data were collected in the McNary Dam tailrace during nine days in July 1988 to improve our understanding of the predator-smolt functional response. (3) Selective predation by northern squawfish. Laboratory and field protocols were developed to evaluate northern squawfish selection and prey vulnerability. Results from laboratory studies suggest that northern squawfish prefer dead over live prey and that descaled prey may be more vulnerable to predation than non-descaled prey. Stressed and unstressed prey were consumed in equal proportions when predation occurred for 6 or 24 h. Physiological and behavioral effects of stress on juvenile salmon are presented. 100 refs., 13 figs., 12 tabs.

  4. Significance of Selective Predation and Development of Prey Protection Measures for Juvenile Salmonids in the Columbia and Snake River Reservoirs: Annual Report, February 1992-February 1993.

    Energy Technology Data Exchange (ETDEWEB)

    Poe, Thomas P.; Gadomski, Dena M.

    1994-09-01

    This document is the 1992 annual report of progress for the Bonneville Power Administration (BPA) research Project No. 82-003 conducted by the U.S. Fish and Wildlife Service (FWS), the Oregon Cooperative Fishery Research Unit (OCFRU), and the Idaho Cooperative Fish and Wildlife Research Unit (ICFWRU). The approach was to present the progress achieved during 1992 in a series of separate reports for each major project task. Each report is prepared in the format of a scientific paper and is able to stand alone, whatever the state of progress or completion. Reports 1, 2, and 4 consist of the Abstract only (journal papers were submitted in lieu of reports). This project has two major goals. One is to understand the significance of selective predation and prey vulnerability by determining if substandard juvenile salmonids (dead, injured, stressed, diseased, or naive) are more vulnerable to predation by northern squawfish, Ptychocheilus oregonensis, than standard or normal juvenile salmonids. The second goal is to develop and test prey protection measures to control predation on juvenile salmonids by reducing predator-smolt encounters or predator capture efficiency. Separate abstracts have been submitted to the database for the seven articles in this report.

  5. Juvenile Salmonid Pit-Tag Studies at Prosser Dam and the Chandler Canal Fish Collection Facility, Yakima River, 1991 and 1992 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Ruehle, Thomas E.; Sandford, Benjamin P.

    1996-01-01

    In 1991 and 1992, the National Marine Fisheries Service completed the second and third years of a 3-year study to estimate juvenile salmonid (Oncorhynchus spp.) timing and survival characteristics related to passage through the Prosser Dam complex, including the Chandler Canal and the Chandler fish collection facility, on the Yakima River. Yearling chinook (O. tshawyacha) and coho salmon (O. kisutch) were collected at the Chandler facility, PIT tagged, and released at various locations in the Yakima River, Chandler Canal, and the Chandler facility. Individual fish were subsequently detected at PIT-tag detection monitors at the Chandler facility and/or McNary Dam on the Columbia River. Survival through various reaches, PIT-tag detection efficiency, and Chandler Canal fish entrainment proportion parameters were estimated using maximum likelihood techniques. The research objectives in 1991 and 1992 were to: (1) assess the effects of passage through the Chandler Canal and the Chandler facility on the survival of juvenile salmonids, (2) determine the entrainment rate of juvenile salmonids into the Chandler Canal as a function of river flow, and (3) determine the efficiency and reliability of the PIT-tag monitoring system at the Chandler facility. The initial 1990 research plan was expanded in 1991 and 1992 to include several more release locations and many more release days.

  6. Movements and Distribution of Northern Squawfish Downstream of Lower Snake River Dams Relative to the Migration of Juvenile Salmonids, 1992-1993 Completion Report.

    Energy Technology Data Exchange (ETDEWEB)

    Isaak, D.J.; Bjornn, T.C. (University of Idaho, Idaho Cooperative Fish and Wildlife Research Unit, Moscow, ID)

    1996-03-01

    Northern squawfish Ptychocheilus oregonensis movements were monitored downstream of two lower Snake River dams during the juvenile salmonid migrations of 1992 and 1993. During a high flow year in 1993, the abundance of squawfish in the tailrace of Lower Granite Dam peaked in July, after the majority of juveniles had moved past Lower Granite Dam, and peak abundance was inversely related to river discharge. Few squawfish moved into the tailrace of Ice Harbor Dam in 1993 because of the extended period of spill. Distributions of squawfish in the tailrace of Lower Granite Dam varied between and within years and shifted in response to changing prey densities, flow patterns, water temperature, and diel cycles, but fish consistently used low velocity habitats. Data from Ice Harbor Dam is less extensive, but squawfish distributions there appeared to be affected by changing flow patterns and fish used low velocity habitats. The changes in distribution and abundance of squawfish in tailrace areas are evidence that predation on seaward migrating salmonids depends on the timing of migration and size and timing of runoff. Juvenile salmonids migrating in the spring and early summer will probably be less affected by squawfish predation in tailrace areas than salmon that migrate later in the summer.

  7. Acoustic Telemetry Evaluation of Juvenile Salmonid Passage and Survival at John Day Dam, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Weiland, Mark A.; Woodley, Christa M.; Ploskey, Gene R.; Hughes, James S.; Kim, Jin A.; Deng, Zhiqun; Fu, Tao; Fischer, Eric S.; Skalski, J. R.; Townsend, Richard L.; Duncan, Joanne P.; Hennen, Matthew J.; Wagner, Katie A.; Arntzen, Evan V.; Miller, Benjamin L.; Miracle, Ann L.; Zimmerman, Shon A.; Royer, Ida M.; Khan, Fenton; Cushing, Aaron W.; Etherington, D. J.; Mitchell, T. D.; Elder, T.; Batton, George; Johnson, Gary E.; Carlson, Thomas J.

    2013-05-01

    This report presents survival, behavioral, and fish passage results for yearling and subyearling Chinook salmon smolts and juvenile steelhead tagged with JSATS acoustic micro-transmitters as part of a survival study conducted at John Day Dam during 2010. This study was designed to evaluate the passage and survival of yearling and subyearling Chinook salmon and juvenile steelhead to assist managers in identifying dam operations for compliance testing as stipulated by the 2008 Federal Columbia River Power System Biological Opinion and the 2008 Columbia Basin Fish Accords. Survival estimates were based on a single-release survival estimate model.

  8. Acoustic Telemetry Evaluation of Juvenile Salmonid Passage and Survival at John Day Dam, 2011

    Energy Technology Data Exchange (ETDEWEB)

    Weiland, Mark A.; Woodley, Christa M.; Ploskey, Gene R.; Hughes, James S.; Hennen, Matthew J.; Kim, Jin A.; Deng, Zhiqun; Fu, Tao; Skalski, J. R.; Townsend, Richard L.; Wagner, Katie A.; Fischer, Eric S.; Duncan, Joanne P.; Batten, G.; Carlson, Thomas J.; Carpenter, Scott M.; Cushing, Aaron W.; Elder, T.; Etherington, D. J.; Johnson, Gary E.; Khan, Fenton; Miracle, Ann L.; Mitchell, T. D.; Prather, K.; Rayamajhi, Bishes; Royer, Ida; Seaburg, Adam; Zimmerman, Shon A.

    2013-06-21

    This report presents survival, behavioral, and fish passage results for tagged yearling Chinook salmon and juvenile steelhead as part of a survival study conducted at John Day Dam during spring 2011. This study was designed to evaluate the passage and survival of yearling Chinook salmon and juvenile steelhead to assist managers in identifying dam operations for compliance testing as stipulated by the 2008 Federal Columbia River Power System Biological Opinion and the 2008 Columbia Basin Fish Accords. Survival estimates were based on a paired-release survival model.

  9. Juvenile Salmonid and Baitfish Distribution, Abundance and Prey Resources in Selected Areas of Grays Harbor, Washington

    Science.gov (United States)

    1981-09-01

    Hydrozoa , Spionidiae (polychaetes), Calanus spp., Epilabidocera a.mphi- 2 trites, Acartia tonsa, Harpacticoida (copepods), Neotmysis mercedis, Leucon...justified on the basis of their low occurrence and excessive biomass. Based upon the revised data set, juvenile and adult Crangon franciscorum

  10. Development of an Index to Bird Predation of Juvenile Salmonids within the Yakima River, 1999 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Gassley, James M.; Grue, Christian E. (University of Washington, School of Aquatic and Fishery Sciences, Seattle, WA)

    2001-10-01

    Avian predation of fish is suspected to contribute to the loss of juvenile spring chinook salmon in the Yakima Basin, potentially constraining natural production. In 1997 and 1998, the Yakama/Klickitat Fisheries Project (YKFP) and the Washington Department of Fish and Wildlife (WDFW)--whose goal is to increase natural production historically present within the Yakima River--initiated investigations to assess the feasibility of developing an index to avian predation of juvenile salmon within the river. This research--conducted by Dr. Steve Mathews and David Phinney of the University of Washington--confirmed that Ring-billed Gulls and Common Mergansers were the primary avian predators of juvenile salmon, and that under certain conditions could significantly impact migrating smolt populations. Beginning in 1999, the Washington Cooperative Fish and Wildlife Research Unit was asked by the YKFP and the WDFW to continue development of avian consumption indices. Monitoring methods developed by Mathews and Phinney were adopted (with modifications) and monitoring of impacts to juvenile salmon along river reaches and at areas of high predator/prey concentrations (colloquially referred to as ''hotspots'') continued. New efforts initiated in 1999 included piscivorous bird surveys at smolt acclimation sites operated by the Yakama Nation, monitoring of the North Fork Teanaway River for changes in avian piscivore abundance associated with the installation of the Jack Creek acclimation facility, and aerial surveys seeking to identify avian piscivores along the length of the Yakima River. In 1999, piscivorous birds were counted from river banks at hotspots and from a raft or drift boat along river reaches. Consumption by gulls was based on direct observations of foraging success and modeled abundance; consumption by Common Mergansers (which forage underwater) was estimated using published dietary requirements and modeled abundance. A second-order polynomial

  11. Evaluation of Behavioral Guidance Structure on Juvenile Salmonid Passage and Survival at Bonneville Dam in 2009

    Energy Technology Data Exchange (ETDEWEB)

    Faber, Derrek M.; Ploskey, Gene R.; Weiland, Mark A.; Deng, Zhiqun; Hughes, James S.; Kim, Jin A.; Fu, Tao; Fischer, Eric S.; Monter, Tyrell J.; Skalski, J. R.

    2011-03-01

    Pacific Northwest National Laboratory (PNNL) conducted an acoustic-telemetry study at Bonneville Dam in 2009 to evaluate the effects of a behavioral guidance structure (BGS) in the Bonneville Dam second powerhouse forebay on fish passage and survival through the second powerhouse (B2), the dam as a whole, and through the first powerhouse and spillway combined. The BGS was deployed to increase the survival of fish passing through B2 by increasing the percentage of outmigrating smolts entering the B2 Corner Collector (B2CC)—a surface flow outlet known to be a relatively benign route for downstream passage at this dam. The study relied on releases of live Juvenile Salmon Acoustic Telemetry System tagged smolts in the Columbia River and used acoustic telemetry to evaluate the approach, passage, and survival of passing juvenile salmon. Study results indicated that having turbine 11 in service is important for providing flow conditions that are comparable to those observed in pre-BGS years (2004 and 2005) and in 2008. This study supports the U.S. Army Corps of Engineers continual effort to improve conditions for juvenile anadromous fish passing through Columbia River dams.

  12. Survival Rates of Juvenile Salmonids Passing Through the Bonneville Dam and Spillway in 2008

    Energy Technology Data Exchange (ETDEWEB)

    Ploskey, Gene R.; Weiland, Mark A.; Faber, Derrek M.; Deng, Zhiqun; Johnson, Gary E.; Hughes, James S.; Zimmerman, Shon A.; Monter, Tyrell J.; Cushing, Aaron W.; Wilberding, Matthew C.; Durham, Robin E.; Townsend, R. L.; Skalski, J. R.; Buchanan, Rebecca A.; Kim, Jina; Fischer, Eric S.; Meyer, Matthew M.; McComas, Roy L.; Everett, Jason

    2009-12-28

    This report describes a 2008 acoustic telemetry survival study conducted by the Pacific Northwest National Laboratory for the Portland District of the U.S. Army Corps of Engineers. The study estimated the survival of juvenile Chinook salmon and steelhead passing Bonneville Dam (BON) and its spillway. Of particular interest was the relative survival of smolts detected passing through end spill bays 1-3 and 16-18, which had deep flow deflectors immediately downstream of spill gates, versus survival of smolts passing middle spill bays 4-15, which had shallow flow deflectors.

  13. Development of an Index to Bird Predation of Juvenile Salmonids within the Yakima River, 2001 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Major, III, Walter; Grue, Christian E.; Ryding, Kristen E. (University of Washington, School of Aquatic and Fishery Sciences, Seattle, WA)

    2002-08-01

    Avian predation of fish is suspected to contribute to the loss of out-migrating juvenile salmonids in the Yakima Basin, potentially constraining natural and artificial production. In 1997 and 1998, the Yakima/ Klickitat Fisheries Project (YKFP)--whose goal is increasing natural production within the Yakima River--initiated investigations to assess the feasibility of developing an index to avian predation of juvenile salmon within the river. This research confirmed that Ring-billed Gulls and Common Mergansers were the primary avian predators of juvenile salmon (Phinney et al. 1998), and that under certain conditions could significantly impact migrating smolt populations. Beginning in 1999, the Washington Cooperative Fish and Wildlife Research Unit (WACFWRU) was asked by the YKFP to continue development of avian consumption indices. Monitoring methods developed by Phinney et al. (1998) were adopted (with modifications) and monitoring of impacts to juvenile salmon along river reaches and at areas of high predator/prey concentrations (colloquially referred to as ''hotspots'') has continued each year through 2001. In 2001, piscivorous birds were counted from river banks at hotspots and from a raft or drift boat along river reaches. Consumption by gulls at hotspots was based on direct observations of foraging success and modeled abundance; consumption by all other piscivorous birds was estimated using published dietary requirements and modeled abundance. Seasonal patterns of avian piscivore abundance were identified, diurnal patterns of gull abundance at hotspots were identified, and predation indices were calculated for hotspots and river reaches (for both spring and summer). Changes in survey methods in 2001 included the addition of surveys in the ''Canyon'' reach during spring and altering the method of directly measuring gull feeding rates at hotspots. Primary avian predators in 2001 were &apos

  14. Design and Analysis of Salmonid Tagging Studies in the Columbia Basin : Evaluating Wetland Restoration Projects in the Columbia River Estuary using Hydroacoustic Telemetry Arrays to Estimate Movement, Survival, and Residence Times of Juvenile Salmonids, Volume XXII (22).

    Energy Technology Data Exchange (ETDEWEB)

    Perry, Russell W.; Skalski, John R.

    2008-08-01

    Wetlands in the Columbia River estuary are actively being restored by reconnecting these habitats to the estuary, making more wetland habitats available to rearing and migrating juvenile salmon. Concurrently, thousands of acoustically tagged juvenile salmonids are released into the Columbia River to estimate their survival as they migrate through the estuary. Here, we develop a release-recapture model that makes use of these tagged fish to measure the success of wetland restoration projects in terms of their contribution to populations of juvenile salmon. Specifically, our model estimates the fraction of the population that enter the wetland, survival within the wetland, and the mean residence time of fish within the wetland. Furthermore, survival in mainstem Columbia River downstream of the wetland can be compared between fish that remained the mainstem and entered the wetland. These conditional survival estimates provide a means of testing whether the wetland improves the subsequent survival of juvenile salmon by fostering growth or improving their condition. Implementing such a study requires little additional cost because it takes advantage of fish already released to estimate survival through the estuary. Thus, such a study extracts the maximum information at minimum cost from research projects that typically cost millions of dollars annually.

  15. Predation by Northern Pikeminnow and tiger muskellunge on juvenile salmonids in a high–head reservoir: Implications for anadromous fish reintroductions

    Science.gov (United States)

    Sorel, Mark H.; Hansen, Adam G.; Connelly, Kristin A.; Wilson, Andrew C.; Lowery, Erin D.; Beauchamp, David A.

    2016-01-01

    salmonids. This study highlights the importance of evaluating trophic interactions within reservoirs slated for reintroduction with anadromous salmonids, as they can be functional migration corridors and may offer profitable juvenile-rearing habitats despite hosting abundant predator populations.

  16. Skin reflectance as a non-lethal measure of smoltification for juvenile salmonids

    Science.gov (United States)

    Haner, Philip V.; Faler, Joyce C.; Schrock, Robin M.; Rondorf, Dennis W.; Maule, Alec G.

    1995-01-01

    Our efforts to find nonlethal methods of assessing the parr-smoll transformation of juvenile steelhead Oncorhynchus mykiss and spring and fall chinook salmon O. tshawytscha led to the development of a video system for quantitatively measuring skin silvering using skin reflectance. Gill Na'.K'-ATPase activity, skin guanine concentration, and skin reflectance were recorded from groups of fish marked with freeze brands at hatcheries and downstream sample sites in the Columbia River basin. Skin reflectance of migrants was significantly higher than that of fish before release; nonmigrants (released fish that did not migrate) had significantly lower skin reflectance than migrants from the same groups. Skin reflectance was significantly correlated with gill ATPasc activity and skin guanine concentration. Skin reflectance increased during the parrsmolt transformation and could be used as a nonlethal indicator of smoltification.

  17. Predation by Resident Fish on Juvenile Salmonids in John Day Reservoir: Final Report, 1983-1986: Volume 1, Final Report of Research.

    Energy Technology Data Exchange (ETDEWEB)

    Poe, Thomas P.; Rieman, Bruce E.

    1988-07-01

    In 1982 the NPPC included in its Fish and Wildlife Program a measure that called for studies ''... to investigate juvenile salmon and steelhead losses to predators while these fish are migrating through Columbia and Snake River reservoirs.'' In the same year the Bonneville Power Administration (BPA) funded ODFW and FWS to conduct collaborative studies to estimate the number of juvenile salmonids lost to predators in John Day Reservoir. Also included as study objectives were: (1) a description of the importance of predation losses relative to mortality at the dam and total reservoir mortality; (2) a description of how predation losses might vary (spatially and temporally); and (3) recommendations of measures to control predation on smolts. We studied four species of predator: northern squawfish, walleye, smallmouth bass, and channel catfish. We selected John Day Reservoir as the study site because the following factors led us to believe if predation was a problem in any reservoir, it would be most obvious there because: (1) the reservoir is an important subyearling chinook rearing area; (2) passage and residualism of juvenile salmonids were considered a problem there; and (3) substantial populations of predators were known to reside in the reservoir. Individual reports were processed separately for the data base.

  18. System-Wide Significance of Predation on Juvenile Salmonids in Columbia and Snake River Reservoirs and Evaluation of Predation Control Measures : Annual Report 1993.

    Energy Technology Data Exchange (ETDEWEB)

    Gadomski, Dena M.; Petersen, James H.; Poe, Thomas P.

    1993-12-01

    This project had three major goals. The first was to assist the Oregon Department of Fish and Wildlife with predation indexing as part of an effort to estimate the relative magnitude of juvenile salmonid losses to northern squawfish Ptychocheilus oregonensis in reservoirs throughout the Columbia River Basin. The second goal was to evaluate the northern squawfish control program and test critical assumptions about mid-reservoir predation processes. The final goal was to determine mechanisms underlying northern squawfish recruitment and factors affecting year-class strength.

  19. Preliminary Estimates of Loss of Juvenile Anadromous Salmonids to Predators in John Day Reservoir and Development of a Predation Model : Interim Report, 1986.

    Energy Technology Data Exchange (ETDEWEB)

    Rieman, Bruce E.

    1986-03-01

    We made preliminary estimates of the loss of juvenile salmonids to predation by walleye, Stizostedion v. vitreum, and northern squawfish, Ptychocheilus oregonensis, in John Day Reservoir in 1984 and 1985 using estimates of predator abundance and daily prey consumption rates. Preliminary estimates may be biased and may be adjusted as much as 30%, but indications are that predation could account for the majority of unexplained loss of juvenile salmonids in John Day Reservoir. Total loss was estimated at 4.1 million in 1984 and 3.3 million in 1985. Northern squawfish consumed 76% and 92% of these totals, respectively. The majority of loss occurred in mid reservoir areas, but loss in a small area, the boat-restricted zone immediately below McNary Dam, was disproportionately large. Peaks in loss in May and July corresponded with peaks in availability of salmonids. Estimated mortality from predation for April through June in 1984 and 1985 was 9% and 7% respectively, for chinook salmon, Oncorhynchus tshawytscha, and 10% and 15% for steelhead, Salmogairdneri. Mortality was variable with time but tended to increase over the period of migration. Mortality of chinook was estimated at 26% to 55% during July and August. A model of predation in John Day Reservoir is outlined. The model includes a predation submodel that can calculate loss from predator number and consumption rate; a population submodel that can relate predator abundance and population structure to recruitment, exploitation, natural mortality and growth; and a distribution submodel that can apportion predators among areas of the reservoir over time. Applications of the model are discussed for projecting expected changes in predation over time and identifying management alternatives that might limit the impact of predation.

  20. Characterization of Gatewell Orifice Lighting at the Bonneville Dam Second Powerhouse and Compendium of Research on Light Guidance with Juvenile Salmonids

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Robert P.; Simmons, Mary Ann

    2007-12-29

    The goal of the study described in this report is to provide U.S. Army Corps of Engineers (USACE) biologists and engineers with general design guidelines for using artificial lighting to enhance the passage of juvenile salmonids into the collection channel at the Bonneville Dam second powerhouse (B2). During fall 2007, Pacific Northwest National Laboratory (PNNL) researchers measured light levels in the field at one powerhouse orifice through which fish must pass to reach the collection channel. Two light types were evaluated—light-emitting diode (LED) lights and halogen spot lights. Additional measurements with mercury lamps were made at the PNNL Aquatic Research Laboratory to determine baseline intensity of the current lighting. A separate chapter synthesizes the relevant literature related to light and fish guidance for both field and laboratory studies. PNNL will also review the Corps plans for existing lighting protocol at all of the Portland District projects and help develop a uniform lighting scheme which could be implemented. The specific objectives for this study are to 1. Create a synthesis report of existing lighting data for juvenile salmonid attraction and deterrence and how the data are used at fish bypass facilities. 2. Evaluate current B2 orifice lighting conditions with both LED and halogen sources. 3. Make recommendations as to what lighting intensity, source, and configuration would improve passage at the B2 orifices. 4. Review USACE plans for retrofit of existing systems (to be assessed at a later date).

  1. Acoustic Imaging Evaluation of Juvenile Salmonid Behavior in the Immediate Forebay of the Water Temperature Control Tower at Cougar Dam, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Fenton; Johnson, Gary E.; Royer, Ida M.; Phillips, Nathan RJ; Hughes, James S.; Fischer, Eric S.; Ploskey, Gene R.

    2011-10-01

    This report presents the results of an evaluation of juvenile Chinook salmonid (Oncorhynchus tshawytscha) behavior in the immediate forebay of the Water Temperature Control (WTC) tower at Cougar Dam in 2010. The study was conducted by the Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers. The overall goal of the study was to characterize juvenile salmonid behavior and movement patterns in the immediate forebay of the WTC tower for fisheries resource managers to use to make decisions on bioengineering designs for long-term structures and/or operations to facilitate safe downstream passage for juvenile salmonids. We collected acoustic imaging (Dual-Frequency Identification Sonar; DIDSON) data from February 1, 2010 through January 31, 2011 to evaluate juvenile salmonid behavior year-round in the immediate forebay surface layer of the WTC tower (within 20 m, depth 0-5 m). From October 28, 2010 through January 31, 2011 a BlueView acoustic camera was also deployed in an attempt to determine its usefulness for future studies as well as augment the DIDSON data. For the DIDSON data, we processed a total of 35 separate 24-h periods systematically covering every other week in the 12-month study. Two different 24-hour periods were processed for the BlueView data for the feasibility study. Juvenile salmonids were present in the immediate forebay of the WTC tower throughout 2010. The juvenile salmonid abundance index was low in the spring (<200 fish per sample-day), began increasing in late April and peaked in mid-May. Fish abundance index began decreasing in early June and remained low in the summer months. Fish abundance increased again in the fall, starting in October, and peaked on November 8-9. A second peak occurred on December 22. Afterwards, abundance was low for the rest of the study (through January 2011). Average fish length for juvenile salmonids during early spring 2010 was 214 {+-} 86 mm (standard deviation). From May through early November

  2. Predation by Resident Fish on Juvenile Salmonids in John Day Reservoir: Final Report, 1983-1986: Volume 2: Supplemental Papers and Data Documentation.

    Energy Technology Data Exchange (ETDEWEB)

    Poe, Thomas P.; Rieman, Bruce E.

    1988-07-01

    In 1982 the NPPC included in its Fish and Wildlife Program measure that called for studies ''... to investigate juvenile salmon and steelhead losses to predators while these fish are migrating through Columbia and Snake River reservoirs.'' In the same year the Bonneville Power Administration (BPA) funded ODFW and FWS to conduct collaborative studies to estimate the number of juvenile salmoids lost to predators in John Day Reservoir. Also included as study objectives were: (1) a description of the importance of predation losses relative to mortality at the dam and total reservoir mortality; (2) a description of how predation losses might vary (spatially and temporally); and (3) recommendations of measures to control predation on smolts. We studied four species of predator; northern squawfish, walleye, smallmouth bass, and channel catfish. We selected John Day Reservoir as the study site because the following factors led us to believe if predation was a problem in any reservoir, it would be most obvious there because: (1) the reservoir is an important subyearling chinook rearing area; (2) passage and residualism of juvenile salmonids were considered a problem there; and (3) substantial populations of predators were known to reside in the reservoir. Individual reports were processed separately for the data base.

  3. Survival Estimates for the Passage of Spring-Migrating Juvenile Salmonids through Snake and Columbia River Dams and Reservoirs, 2004-2005 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Steven G.; Muir, William D.; Marsh, Douglas M. (National Marine Fisheries Service, Northwest Fisheries Science Center, Fish Ecology Division, Seattle, WA)

    2005-10-01

    In 2004, the National Marine Fisheries Service and the University of Washington completed the twelfth year of a study to estimate survival and travel time of juvenile salmonids (Oncorhynchus spp.) passing through dams and reservoirs on the Snake and Columbia Rivers. All estimates were derived from detections of fish tagged with passive integrated transponder tags (PIT tags). We PIT tagged and released a total of 19,621 hatchery steelhead, 8,128 wild steelhead, and 9,227 wild yearling Chinook salmon at Lower Granite Dam. In addition, we utilized fish PIT tagged by other agencies at traps and hatcheries upstream from the hydropower system and sites within the hydropower system. PIT-tagged smolts were detected at interrogation facilities at Lower Granite, Little Goose, Lower Monumental, McNary, John Day, and Bonneville Dams and in the PIT-tag detector trawl operated in the Columbia River estuary. Survival estimates were calculated using a statistical model for tag-recapture data from single release groups (the single-release model). Primary research objectives in 2004 were to (1) estimate reach survival and travel time in the Snake and Columbia Rivers throughout the migration period of yearling Chinook salmon O. tshawytscha and steelhead O. mykiss; (2) evaluate relationships between survival estimates and migration conditions; and (3) evaluate the survival-estimation models under prevailing conditions. This report provides reach survival and travel time estimates for 2004 for PIT-tagged yearling Chinook salmon (hatchery and wild), hatchery sockeye salmon O. nerka, hatchery coho salmon O. kisutch, and steelhead (hatchery and wild) in the Snake and Columbia Rivers. Results are reported primarily in the form of tables and figures; details on methodology and statistical models used are provided in previous reports cited here. Survival and detection probabilities were estimated precisely for most of the 2004 yearling Chinook salmon and steelhead migrations. Hatchery and

  4. Ecology of Juvenile Salmonids in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta, Lower Columbia River, 2007

    Energy Technology Data Exchange (ETDEWEB)

    Sobocinski, Kathryn L.; Johnson, Gary E.; Sather, Nichole K.; Storch, Adam; Jones, Tucker A.; Mallette, Christine; Dawley, Earl M.; Skalski, John R.; Teel, David; Moran, Paul

    2008-03-18

    This document is the first annual report for the study titled “Ecology of Juvenile Salmonids in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta in the Lower Columbia River.” Hereafter, we refer to this research as the Tidal Freshwater Monitoring (TFM) Study. The study is part of the research, monitoring, and evaluation effort developed by the Action Agencies (Bonneville Power Administration, U.S. Army Corps of Engineers, U.S. Bureau of Reclamation) in response to obligations arising from the Endangered Species Act as a result of operation of the Federal Columbia River Power System (FCRPS). The project is performed under the auspices of the Northwest Power and Conservation Council’s Columbia Basin Fish and Wildlife Program.

  5. 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

  6. Introduced northern pike consumption of salmonids in Southcentral Alaska

    Science.gov (United States)

    Sepulveda, Adam J.; Rutz, David S.; Dupuis, Aaron W; Shields, Patrick A; Dunker, Kristine J.

    2015-01-01

    The impacts of introduced northern pike (Esox lucius) on salmonid populations have attracted much attention because salmonids are popular subsistence, sport and commercial fish. Concern over the predatory effects of introduced pike on salmonids is especially high in Southcentral Alaska, where pike were illegally introduced to the Susitna River basin in the 1950s. We used pike abundance, growth, and diet estimates and bioenergetics models to characterise the realised and potential consumptive impacts that introduced pike (age 2 and older) have on salmonids in Alexander Creek, a tributary to the Susitna River. We found that juvenile salmonids were the dominant prey item in pike diets and that pike could consume up to 1.10 metric tons (realised consumption) and 1.66 metric tons (potential consumption) of juvenile salmonids in a summer. Age 3–4 pike had the highest per capita consumption of juvenile salmonids, and age 2 and age 3–4 pike had the highest overall consumption of juvenile salmonid biomass. Using historical data on Chinook salmon and pike potential consumption of juvenile salmonids, we found that pike consumption of juvenile salmonids may lead to collapsed salmon stocks in Alexander Creek. Taken together, our results indicate that pike consume a substantial biomass of juvenile salmonids in Alexander Creek and that coexistence of pike and salmon is unlikely without management actions to reduce or eliminate introduced pike.

  7. Migrational Characteristics, Biological Observations, and Relative Survival of Juvenile Salmonids Entering the Columbia River Estuary, 1966-1983, 1985 Final Report of Research.

    Energy Technology Data Exchange (ETDEWEB)

    Dawley, Earl M.

    1986-04-01

    Natural runs of salmonids in the Columbia River basin have decreased as a result of hydroelectric-dam development, poor land- and forest-management, and over-fishing. This has necessitated increased salmon culture to assure adequate numbers of returning adults. Hatchery procedures and facilities are continually being modified to improve both the efficiency of production and the quality of juveniles produced. Initial efforts to evaluate changes in hatchery procedures were dependent upon adult contributions to the fishery and returns to the hatchery. Procedures were developed for sampling juvenile salmon and steelhead entering the Columbia River estuary and ocean plume. The sampling of hatchery fish at the terminus of their freshwater migration assisted in evaluating hatchery production techniques and identifying migrational or behavioral characteristics that influence survival to and through the estuary. The sampling program attempted to estimate survival of different stocks and define various aspects of migratory behavior in a large river, with flows during the spring freshet from 4 to 17 thousand cubic meters per second (m/sup 3//second).

  8. Ecology of Juvenile Salmonids in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta, Lower Columbia River, 2007 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Sobocinski, Kathryn; Johnson, Gary; Sather, Nichole [Pacific Northwest National Laboratory

    2008-03-17

    This document is the first annual report for the study titled 'Ecology of Juvenile Salmonids in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta in the Lower Columbia River'. Hereafter, we refer to this research as the Tidal Freshwater Monitoring (TFM) Study. The study is part of the research, monitoring, and evaluation effort developed by the Action Agencies (Bonneville Power Administration, U.S. Army Corps of Engineers, U.S. Bureau of Reclamation) in response to obligations arising from the Endangered Species Act as a result of operation of the Federal Columbia River Power System (FCRPS). The project is performed under the auspices of the Northwest Power and Conservation Council's Columbia Basin Fish and Wildlife Program. The goal of the 2007-2009 Tidal Freshwater Monitoring Study is to answer the following questions: In what types of habitats within the tidal freshwater area of the lower Columbia River and estuary (LCRE; Figure 1) are yearling and subyearling salmonids found, when are they present, and under what environmental conditions?1 And, what is the ecological importance2 of shallow (0-5 m) tidal freshwater habitats to the recovery of Upper Columbia River spring Chinook salmon and steelhead and Snake River fall Chinook salmon? Research in 2007 focused mainly on the first question, with fish stock identification data providing some indication of Chinook salmon presence at the variety of habitat types sampled. The objectives and sub-objectives for the 2007 study were as follows: (1) Habitat and Fish Community Characteristics-Provide basic data on habitat and fish community characteristics for yearling and subyearling salmonids at selected sites in the tidal freshwater reach in the vicinity of the Sandy River delta. (1a) Characterize vegetation assemblage percent cover, conventional water quality, substrate composition, and beach slope at each of six sampling sites in various tidal freshwater habitat types. (1b

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

    Science.gov (United States)

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

    2008-01-01

    Introductions of nonnative northern pike Esox lucius have created recreational fisheries in many waters in the United States and Canada, yet many studies have shown that introduced northern pike may alter the composition and structure of fish communities through predation. We estimated the abundance of nonnative northern pike (2002-2003) and applied food habits data (1999-2003) to estimate their annual consumption of native bull trout Salvelinus confluentus and westslope cutthroat trout Oncorhynchus clarkii lewisi juveniles in the upper Flathead River system, Montana. Population estimates were generally consistent among years and ranged from 1,200 to 1,300 individuals. Westslope cutthroat trout were present in the diet of younger (???600 mm) and older (>600 mm) northern pike during all seasons and bull trout were found only in larger northern pike during all seasons but summer. Bioenergetics modeling estimated that the northern pike population annually consumed a total of 8.0 metric tons (mt) of fish flesh; the highest biomass was composed of cyprinids (4.95 mt) followed by whitefishes Prosopium spp. (1.02 mt), bull trout (0.80 mt), westslope cutthroat trout (0.68 mt), yellow perch Perca flavescens (0.41 mt),1 and other fishes (centrarchids and cottids; 0.14 mt). Numerically, the northern pike population consumed more than 342,000 fish; cyprinids and catostomids comprised approximately 82% of prey fish (278,925), whereas over 13,000 westslope cutthroat trout and nearly 3,500 bull trout were eaten, comprising about 5% of the prey consumed. Our results suggest that predation by introduced northern pike is contributing to the lower abundance of native salmonids in the system and that a possible benefit might accrue to native salmonids by reducing these predatory interactions. ?? Copyright by the American Fisheries Society 2008.

  10. Survival Estimates for the Passage of Spring-Migrating Juvenile Salmonids through Snake and Columbia River Dams and Reservoirs, 2003-2004 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Steven G.; Muir, William D.; Zabel, Richard W. (NOAA Fisheries Science Center, Seattle, WA)

    2004-01-01

    For juvenile chinook salmon Oncorhynchus tshawytscha, sockeye salmon O. nerka, and steelhead O. mykiss that migrate through reservoirs, hydroelectric projects, and free-flowing sections of the Snake and Columbia Rivers, survival estimates are essential to develop effective strategies for recovering depressed stocks. Many management strategies were based on estimates of system survival (Raymond 1979; Sims and Ossiander 1981) derived in a river system considerably different from today's (Williams and Matthews 1995; Williams et al. 2001). Knowledge of the magnitude, locations, and causes of smolt mortality under present passage conditions, and under conditions projected for the future, are necessary to develop strategies that will optimize smolt survival during migration. From 1993 through 2002, the National Marine Fisheries Service (NMFS) and the University of Washington (UW) demonstrated the feasibility of using three statistical models to estimate survival of PIT-tagged (Prentice et al. 1990a) juvenile salmonids passing through Snake River dams and reservoirs (Iwamoto et al. 1994; Muir et al. 1995, 1996, 2001a, 2003; Smith et al. 1998, 2000a,b; Hockersmith et al. 1999; Zabel et al. 2001, 2002). Evaluation of assumptions for these models indicated that all were generally satisfied, and accurate and precise survival estimates were obtained. In 2003, NMFS and UW completed the eleventh year of the study. Flow levels during the early portion of the 2003 spring migration were similar to 2002, and only slightly higher than in the drought conditions during 2001. However, flow levels were much greater during the later part of the migration in 2003. Spill levels were similar to 2002, much higher than in 2001. Research objectives were to: (1) estimate reach survival and travel time in the Snake and Columbia Rivers throughout the yearling chinook salmon and steelhead migrations; (2) evaluate relationships between survival estimates and migration conditions; and (3

  11. Survival Estimates for the Passage of Spring-Migrating Juvenile Salmonids through Snake and Columbia River Dams and Reservoirs, 2000 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Zabel, Richard; Smith, Steven G.; Muir, William D. (Northwest and Alaska Fisheries Science Center, Fish Ecology Division, Seattle, WA)

    2001-02-01

    In 2000, the National Marine Fisheries Service and the University of Washington completed the eight year of a study to estimate survival of juvenile salmonids (Oncorhynchus spp.) passing through dams and reservoirs on the Snake and Columbia Rivers. A total of 20,313 hatchery steelhead were tagged with passive integrated transpoder (PIT) tags and released at Lower Granite Dam for reach survival estimation. They did not PIT tag any yearlying chinook salmon (O. tshawytscha) for reach survival estimates in 2000 because sufficient numbers for these estimates were available from other studies. Primary research objectives in 2000 were (1) to estimate reach and project survival in the Snake and Columbia Rivers throughout the yearling chinook salmon and steelhead migrations, and (2) to evaluate the survival-estimation models under prevailing conditions. In addition, they estimated survival from point of release to Lower Granite Dam and below for chinook salmon, steelhead, and sockeye salmon (O.nerka) PIT tagged and released at Snake River basin hatcheries and chinook salmon and steelhead PIT tagged and released at Snake River basin hatcheries and chinook salmon and steelhead PIT tagged and released at Snake River basin smolt traps. This report provides reach survival and travel time estimates for 2000 for PIT-tagged yearling chinook salmon and steelhead (hatchery and wild) in the Snake and Columbia Rivers. Results are reported primarily in the form of tables and figures. Further details on methodology and statistical models used are provided in previous reports cited in the text.

  12. Feasibility Study for Evaluating Cumulative Exposure of Downstream Migrant Juvenile Salmonids to Total Dissolved Gas. Final Report 1996.

    Energy Technology Data Exchange (ETDEWEB)

    Abernethy, C.Scott; Dauble, Dennis D.; Johnson, Robert L. [Pacific Northwest National Laboratory, Richland, WA (United States)

    1997-11-01

    A feasibility study was initiated to determine if downstream migrant salmonids could be monitored to determine potential relationships between total dissolved gas (TDG) exposure and signs of gas bubble trauma (GBT). The primary objectives were to: (1) establish logistical requirements for in-river monitoring of TDG exposure, including net pen design, deployment, and navigation constraints; (2) resolve uncertainties associated with effects of the net pen on fish behavior; (3) test the accuracy and precision of in-river monitoring equipment used to measure fish distribution and water quality; and (4) determine the application of hydrologic/flow models to predictions of TDG exposure. In-river measurements included water velocity, boat position, and selected water quality parameters (temperature, dissolved oxygen, pH, depth, conductivity). Fish distribution within the net pen was monitored using scanning sonar, and a split-beam echo sounder was used to evaluate vertical distribution of fish m in the river adjacent to the net pen. Three test drifts were conducted from late July through late August. The studies demonstrated that it was feasible to assemble and deploy a large net pen for mobile monitoring of TDG exposure. Accurate monitoring of vertical and lateral distribution of smolts was performed, and diel differences in behavior were documented. Further, the fish sounded in response to researcher activity on the perimeter platform. Thus, in-transit monitoring for GBT or mortality would affect fish depth distribution and exposure to TDG. Principal recommendations for future studies are directed at improving maneuverability of the net pen in adverse weather conditions and applying new acoustics technology to simultaneously collect fish distribution data from within and outside of the pen. 6 refs., 17 figs., 2 tabs.

  13. A Markov chain analysis of the movements of juvenile salmonids in the forebay of McNary Dam, Washington and Oregon, 2006-09

    Science.gov (United States)

    Adams, Noah S.; Hatton, Tyson W.

    2012-01-01

    Passage and survival data for yearling and subyearling Chinook salmon and juvenile steelhead were collected at McNary Dam between 2006 and 2009. These data have provided critical information for resource managers to implement structural and operational changes designed to improve the survival of juvenile salmonids as they migrate past the dam. Much of the information collected at McNary Dam was in the form of three-dimensional tracks of fish movements in the forebay. These data depicted the behavior of multiple species (in three dimensions) during different diel periods, spill conditions, powerhouse operations, and test configurations of the surface bypass structures (temporary spillway weirs; TSWs). One of the challenges in reporting three-dimensional results is presenting the information in a manner that allows interested parties to summarize the behavior of many fish over many different conditions across multiple years. To accomplish this, we investigated the feasibility of using a Markov chain analysis to characterize fish movement patterns in the forebay of McNary Dam. The Markov chain analysis is one way that can be used to summarize numerically the behavior of fish in the forebay. Numerically summarizing the behavior of juvenile salmonids in the forebay of McNary Dam using the Markov chain analysis allowed us to confirm what had been previously summarized using visualization software. For example, proportions of yearling and subyearling Chinook salmon passing the three powerhouse areas was often greater in the southern and middle areas, compared to the northern area. The opposite generally was observed for steelhead. Results of this analysis also allowed us to confirm and quantify the extent of milling behavior that had been observed for steelhead. For fish that were first detected in the powerhouse region, less than 0.10 of the steelhead, on average, passed within each of the powerhouse areas. Instead, steelhead transitioned to adjoining areas in the

  14. Acoustic Imaging Evaluation of Juvenile Salmonid Behavior in the Immediate Forebay of the Water Temperature Control Tower at Cougar Dam, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Fenton; Johnson, Gary E.; Royer, Ida M.; Phillips, Nathan RJ; Hughes, James S.; Fischer, Eric S.; Ham, Kenneth D.; Ploskey, Gene R.

    2012-04-01

    This report presents the results of an evaluation of juvenile Chinook salmon (Oncorhynchus tshawytscha) behavior at Cougar Dam on the south fork of the McKenzie River in Oregon in 2010. The study was conducted by the Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers (USACE). The overall goal of the study was to characterize juvenile salmonid behavior and movement patterns in the immediate forebay of the Water Temperature Control (WTC) tower of the dam for USACE and fisheries resource managers use in making decisions about bioengineering designs for long-term structures and/or operations to facilitate safe downstream passage for juvenile salmonids. We collected acoustic imaging (Dual-Frequency Identification Sonar; DIDSON) data from March 1, 2010, through January 31, 2011. Juvenile salmonids (hereafter, called 'fish') were present in the immediate forebay of the WTC tower throughout the study. Fish abundance index was low in early spring (<200 fish per sample-day), increased in late April, and peaked on May 19 (6,039 fish). A second peak was observed on June 6 (2904 fish). Fish abundance index decreased in early June and remained low in the summer months (<100 fish per sample-day). During the fall and winter, fish numbers varied with a peak on November 10 (1881 fish) and a minimum on December 7 (12 fish). A second, smaller, peak occurred on December 22 (607 fish). A univariate statistical analysis indicated fish abundance index (log10-transformed) was significantly (P<0.05) positively correlated with forebay elevation, velocity over the WTC tower intake gate weirs, and river flows into the reservoir. A subsequent multiple regression analysis resulted in a model (R2=0.70) predicting fish abundance (log-transformed index values) using two independent variables of mean forebay elevation and the log10 of the forebay elevation range. From the approximate fish length measurements made using the DIDSON imaging software, the average fish

  15. A Markov chain analysis of the movements of juvenile salmonids, including sockeye salmon, in the forebay of McNary Dam, Washington and Oregon, 2006-09

    Science.gov (United States)

    Adams, Noah S.; Hatton, Tyson W.

    2012-01-01

    Passage and survival data were collected at McNary Dam between 2006 and 2009. These data have provided critical information for resource managers to implement structural and operational changes designed to improve the survival of juvenile salmonids as they migrate past the dam. Much of the valuable information collected at McNary Dam was in the form of three-dimensional (hereafter referred to as 3-D) tracks of fish movements in the forebay. These data depicted the behavior of multiple species (in three dimensions) during different diel periods, spill conditions, powerhouse operations, and testing of the surface bypass structures (temporary spillway weirs; TSWs). One of the challenges in reporting 3-D results is presenting the information in a manner that allows interested parties to summarize the behavior of many fish over many different conditions across multiple years. To accomplish this, we used a Markov chain analysis to characterize fish movement patterns in the forebay of McNary Dam. The Markov chain analysis allowed us to numerically summarize the behavior of fish in the forebay. This report is the second report published in 2012 that uses this analytical method. The first report included only fish released as part of the annual studies conducted at McNary Dam. This second report includes sockeye salmon that were released as part of studies conducted by the Chelan and Grant County Public Utility Districts at mid-Columbia River dams. The studies conducted in the mid-Columbia used the same transmitters as were used for McNary Dam studies, but transmitter pulse width was different between studies. Additionally, no passive integrated transponder tags were implanted in sockeye salmon. Differences in transmitter pulse width resulted in lower detection probabilities for sockeye salmon at McNary Dam. The absence of passive integrated transponder tags prevented us from determining if fish passed the powerhouse through the juvenile bypass system (JBS) or turbines. To

  16. Development of an Index to Bird Predation of Juvenile Salmonids within the Yakima River, 2000 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Grassley, James M.; Grue, Christian E.; Major, III, Walter (University of Washington, School of Aquatic and Fishery Science, Seattle, WA)

    2002-01-01

    Avian predation of fish is suspected to contribute to the loss of juvenile spring chinook salmon in the Yakima Basin, potentially constraining natural production. In 1997 and 1998, the Yakama/Klickitat Fisheries Project (YKFP) and the Washington Department of Fish and Wildlife (WDFW)--whose goal is to increase natural production historically present within the Yakima River--initiated investigations to assess the feasibility of developing an index to avian predation of juvenile salmon within the river. This research--conducted by Dr. Steve Mathews and David Phinney of the University of Washington--confirmed that Ring-billed Gulls and Common Mergansers were the primary avian predators of juvenile salmon, and that under certain conditions could impact migrating smolt populations. Beginning in 1999, the Washington Cooperative Fish and Wildlife Research Unit (WACFWRU) was asked by the YKFP and the WDFW to continue development of avian consumption indices. Monitoring methods developed by Phinney et al. (1998) were adopted (with modifications) and monitoring of impacts to juvenile salmon along river reaches and at areas of high predator/prey concentrations (colloquially referred to as ''hotspots'') continued through 2000. In 2000, piscivorous birds were counted from river banks at hotspots and from a raft or drift boat along river reaches. Consumption by gulls at Hotspots was based on direct observations of foraging success and modeled abundance; consumption by all other piscivorous birds was estimated using published dietary requirements and modeled abundance. Further development of the avian consumption index model provided an estimation of smolt consumption for the 2000 survey season. Seasonal patterns of avian piscivore abundance were identified, diurnal patterns of gull abundance at hotspots were identified, predation indices were calculated for hotspots and spring and summer river reaches, and the efficacy of aerial surveys for estimating bird

  17. Development of an Index to Bird Predation of Juvenile Salmonids within the Yakima River, 2000 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Grassley, James M.; Grue, Christian E.; Major, III, Walter (University of Washington, School of Aquatic and Fishery Science, Seattle, WA)

    2002-01-01

    Avian predation of fish is suspected to contribute to the loss of juvenile spring chinook salmon in the Yakima Basin, potentially constraining natural production. In 1997 and 1998, the Yakama/Klickitat Fisheries Project (YKFP) and the Washington Department of Fish and Wildlife (WDFW)--whose goal is to increase natural production historically present within the Yakima River--initiated investigations to assess the feasibility of developing an index to avian predation of juvenile salmon within the river. This research--conducted by Dr. Steve Mathews and David Phinney of the University of Washington--confirmed that Ring-billed Gulls and Common Mergansers were the primary avian predators of juvenile salmon, and that under certain conditions could impact migrating smolt populations. Beginning in 1999, the Washington Cooperative Fish and Wildlife Research Unit (WACFWRU) was asked by the YKFP and the WDFW to continue development of avian consumption indices. Monitoring methods developed by Phinney et al. (1998) were adopted (with modifications) and monitoring of impacts to juvenile salmon along river reaches and at areas of high predator/prey concentrations (colloquially referred to as ''hotspots'') continued through 2000. In 2000, piscivorous birds were counted from river banks at hotspots and from a raft or drift boat along river reaches. Consumption by gulls at Hotspots was based on direct observations of foraging success and modeled abundance; consumption by all other piscivorous birds was estimated using published dietary requirements and modeled abundance. Further development of the avian consumption index model provided an estimation of smolt consumption for the 2000 survey season. Seasonal patterns of avian piscivore abundance were identified, diurnal patterns of gull abundance at hotspots were identified, predation indices were calculated for hotspots and spring and summer river reaches, and the efficacy of aerial surveys for estimating bird

  18. Integrated Status and Effectiveness Monitoring Program Population Estimates for Juvenile Salmonids in Nason Creek, WA ; 2008 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Matthew; Murdoch, Keely [Yakama Nation Fisheries Resource Management

    2009-07-20

    This report summarizes juvenile coho, spring Chinook, and steelhead salmon migration data collected at a 1.5m diameter cone rotary fish trap on Nason Creek during 2008; providing abundance and freshwater productivity estimates. We used species enumeration at the trap and efficiency trials to describe emigration timing and to estimate the number of emigrants. Trapping began on March 2, 2008 and was suspended on December 11, 2008 when snow and ice accumulation prevented operation. During 2008, 0 brood year (BY) 2006 coho, 1 BY2007 coho, 906 BY2006 spring Chinook, 323 BY2007 fry Chinook, 2,077 BY2007 subyearling Chinook, 169 steelhead smolts, 414 steelhead fry and 2,390 steelhead parr were trapped. Mark-recapture trap efficiency trials were performed over a range of stream discharge stages. A total of 2,639 spring Chinook, 2,154 steelhead and 12 bull trout were implanted with Passive Integrated Transponder (PIT) tags. Most PIT tagged fish were used for trap efficiency trials. We were unable to identify a statistically significant relationship between stream discharge and trap efficiency, thus, pooled efficiency estimates specific to species and trap size/position were used to estimate the number of fish emigrating past the trap. We estimate that 5,259 ({+-} 359; 95% CI) BY2006 Chinook, 16,816 ({+-} 731; 95% CI) BY2007 Chinook, and 47,868 ({+-} 3,780; 95% CI) steelhead parr and smolts emigrated from Nason Creek in 2008.

  19. 大口黑鲈鱼种弹状病毒病的诊断%Diagnosis of rhabdovirus disease in juvenile largemouth bass Micropterus salmonides

    Institute of Scientific and Technical Information of China (English)

    雷燕; 戚瑞荣; 崔龙波; 肖洋; 张文文; 马家好; 王雪鹏

    2015-01-01

    Diagnosis of acute mortality was investigated in cultured juvenile largemouth bass Micropterus salmonides collected in Foshan, Guangdong Province. The morbid largemouth bass swam on the water surface, had blacken and rotten skin, and fins, and was devoid of food. The postmortem examination revealed that the sick fish had hem-orrhagic gills, swollen liver, spleen and kidney, reddish intestine and empting stomach. Epidemiological survey in-dicated that no pathogenic bacteria and parasites were found in the organs including liver, spleen and kidney, the disease being obvious infectious. The diffused necrosis was histologically observed in liver, spleen and kidney. The specific products with predicted size were obtained in the diseased fish by primers designed according to the se-quence of GenBank. Comparative analysis of nucleotide sequences in the GenBank databases using Blast database network service showed that the putative gene products from the infected largemouth bass shared high homologous i-dentity of 96 . 9% with hybrid snakehead rhabdovirus ( HSHV ) and 95 . 3% with Siniperca chuatsi rhabdovirus ( SCRV) , indicating that the mortality of largemouth bass is caused by rhabdoviruses.%对广东佛山一突发批量急性死亡现象的大口黑鲈Micropterus salmoides养殖池塘中的患病大口黑鲈鱼种进行了研究。结果表明:濒死的大口黑鲈在水面漫游,烂身、烂鳍,停止摄食,严重者体色发黑;解剖病鱼鳃有少量出血点,肝脏严重肿大、充血,脾脏肿大,胃肠空虚,肾脏肿大;流行病学调查发现,该病具有明显的传染性;从病鱼肝脏、脾脏和肾脏中未分离到致病菌,也未检测到大量寄生虫;组织病理切片观察发现,肝脏、脾脏和肾脏均呈弥漫性坏死;参考GenBank中弹状病毒的基因序列,设计并合成检测引物,以从自然发病鱼提取的DNA 作为模板,检测结果显示,病鱼均能扩增出与预期大小片段相

  20. Using small meshed collecting bags on trawls to quantify trawls seabed disturbance of aquatic organisms

    DEFF Research Database (Denmark)

    Krag, Ludvig Ahm

    activities has been documented by collecting samples before and after the fishing process or by comparing areas of different fishing intensity. These investigations are expensive and labor demanding and are inappropriate for documenting effects of smaller technological changes aimed at reducing trawling...... impact on commercial fishing grounds. In this study we develop and test small-meshed collecting bags designed to retain juvenile fish and benthic megafauna. The collecting bags are mounted in the wings and body of the trawl. The catches in the collection bags provide information of the species and size...

  1. Introduced northern pike predation on salmonids in southcentral Alaska

    Science.gov (United States)

    Sepulveda, Adam J.; Rutz, David S.; Ivey, Sam S.; Dunker, Kristine J.; Gross, Jackson A.

    2013-01-01

    Northern pike (Esox lucius) are opportunistic predators that can switch to alternative prey species after preferred prey have declined. This trophic adaptability allows invasive pike to have negative effects on aquatic food webs. In Southcentral Alaska, invasive pike are a substantial concern because they have spread to important spawning and rearing habitat for salmonids and are hypothesised to be responsible for recent salmonid declines. We described the relative importance of salmonids and other prey species to pike diets in the Deshka River and Alexander Creek in Southcentral Alaska. Salmonids were once abundant in both rivers, but they are now rare in Alexander Creek. In the Deshka River, we found that juvenile Chinook salmon (Oncorhynchus tshawytscha) and coho salmon (O. kisutch) dominated pike diets and that small pike consumed more of these salmonids than large pike. In Alexander Creek, pike diets reflected the distribution of spawning salmonids, which decrease with distance upstream. Although salmonids dominated pike diets in the lowest reach of the stream, Arctic lamprey (Lampetra camtschatica) and slimy sculpin (Cottus cognatus) dominated pike diets in the middle and upper reaches. In both rivers, pike density did not influence diet and pike consumed smaller prey items than predicted by their gape-width. Our data suggest that (1) juvenile salmonids are a dominant prey item for pike, (2) small pike are the primary consumers of juvenile salmonids and (3) pike consume other native fish species when juvenile salmonids are less abundant. Implications of this trophic adaptability are that invasive pike can continue to increase while driving multiple species to low abundance.

  2. Winter Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Winter Bottom Trawl Survey was initiated in 1992 and covered offshore areas from the Mid-Atlantic to Georges Bank. Inshore strata were covered...

  3. Spring Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Spring Bottom Trawl Survey was initiated in 1968 and covered an area from Cape Hatteras, NC, to Nova Scotia, Canada, at depths >27m....

  4. Fall Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Fall Bottom Trawl Survey was initiated in 1963 and covered an area from Hudson Canyon, NY to Nova Scotia, Canada. Throughout the years,...

  5. Food habits of Juvenile American Shad and dynamics of zooplankton in the lower Columbia River

    Science.gov (United States)

    Haskell, C.A.; Tiffan, K.F.; Rondorf, D.W.

    2006-01-01

    As many as 2.4 million adult American shad annually pass John Day Dam, Columbia River to spawn upriver, yet food web interactions of juvenile shad rearing in John Day Reservoir are unexplored. We collected zooplankton and conducted mid-water trawls in McNary (June-July) and John Day reservoirs (August-November) from 1994 through 1996 during the outmigration of subyearling American shad and Chinook salmon. Juvenile American shad were abundant and represented over 98% of the trawl catch in late summer. The five major taxa collected in zooplankton tows were Bosmina longirostris, Daphnia, cyclopoid cope-pods, rotifers, and calanoid copepods. We evaluated total crustacean zooplankton abundance and Daphnia biomass in relation to water temperature, flow, depth, diel period, and cross-sectional location using multiple regression. Differences in zooplankton abundance were largely due to differences in water temperature and flow. Spatial variation in total zooplankton abundance was observed in McNary Reservoir, but not in John Day Reservoir. Juvenile American shad generally fed on numerically abundant prey, despite being less preferred than larger bodied zooplankton. A decrease in cladoceran abundance and size in August coupled with large percentages of Daphnia in juvenile American shad stomachs indicated heavy planktivory. Smaller juvenile American shad primarily fed on Daphnia in August, but switched to more evasive copepods as the mean size of fish increased and Daphnia abundance declined. Because Daphnia are particularly important prey items for subyearling Chinook salmon in mainstem reservoirs in mid to late summer, alterations in the cladoceran food base is of concern for the management of outmigrating salmonids and other Columbia River fishes. ?? 2006 by the Northwest Scientific Association. All rights reserved.

  6. Physiological Assessment and Behavioral Interaction of Wild and Hatchery Juvenile Salmonids : The Relationship of Fish Size and Growth to Smoltification in Spring Chinook Salmon.

    Energy Technology Data Exchange (ETDEWEB)

    Beckman, Brian R.; Larsen, Donald A.; Lee-Pawlak, Beeda; Dickhoff, Walton W.

    1996-10-01

    Experiments were performed to determine the relative influence of size and growth rate on downstream migratory disposition and physiology in yearling spring chinook salmon (Oncorhynchus tshawtscha) smolts. A group of juvenile chinook salmon was size graded into small and large categories with half the fish in each group reared at an elevated temperature, resulting in four distinct treatment groups: Large Warm (LW), Large Cool (LC), Small Warm (SW), and Small Cool (SC). Fish from warm-water treatment groups displayed significantly higher growth rates than cool-water groups. Fish were tagged and released into a natural creek where downstream movement was monitored. For each of the two releases, fish that migrated past a weir within the first 5 days postrelease had significantly higher spring growth rates than fish that did not migrate within that period. Significant differences in length for the same fish were only found in the second release. Also for the second release, fish from the warm water treatment groups were recovered in higher proportions than fish from cool water groups. The results indicate that increased growth rate in the spring has a positive relation to downstream migratory disposition. Furthermore, there is a relation between smolt size and migration; however, this relation is weaker than that found between growth rate and migration.

  7. AFSC/ABL: Juvenile rockfish DNA species identification

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Many pelagic juvenile rockfish (Sebastes) were collected in juvenile salmonid surveys in the Gulf of Alaska (GOA) from 1998 to 2002. Often species identification of...

  8. SAB Juvenile Reef Fish (2002-2015)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Trawls were made during the summer months in shallow seagrass beds to monitor the number and species of juvenile snapper using the grass as a nursery.

  9. Salmonids surveys, number of juvenile fish, fork length, and species diversity conducted in the Little Campbell Creek watershed, Alaska from 2010-11-01 to 2011-03-01 (NCEI Accession 0148761)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Over the past few years biologists and other researchers have encountered noticeable fish die-offs, mostly of young salmonid, in various stretches of Little Campbell...

  10. Development of energy efficient mid-water trawls to Murmansk trawl fleets

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    Two experimental trawls were designed as a joint task between the Danish partners and the Russian trawler fleets which were going to test them. The new design incorporate use of modern Western high strength material. The engineering performance of the trawls was analysed using computer based simulation programs and flume tank tests. The new designs were compared with two conventional trawls used by the Russian partners with respect to overall geometry and towing resistance. The new trawls have better performance than the conventional trawls. The vertical opening in the trawl mouth is greater and the towing resistance is less. The trawls fishing capacity was tested and compared with the conventional trawls on commercial fishing trips in August and September 1996. One trawl of a typical Danish two bridle design was far better than the corresponding Russian trawl. In some fisheries the catch per haul was more than four times the catch of the Russian trawl. The other trawl, a four bridle design, which was a compromise between Danish and Russian design philosophies had a catch efficiency comparable to the Russian trawl. The experimental trawls were both easier to tow than to conventional trawls. A reduction in the towing power of 20% for the trawl designed to MurmanRyprom and 30% for the Turbo trawl designed to Murmansk Trawl Fleet when towed at the same speed is foreseen. The reduction in the overall fuel consumption is estimated to 5% and 7% only due to the operation profile and the layout of the vessels. (LN)

  11. Cooperative Research Twin Trawl Sweep Comparison Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The "Twin-Trawl Sweep Efficiency Study" was intended to compare the sweep efficiency and selectivity of the NEFSC standardized bottom trawl to that of a standardized...

  12. Cooperative Research Paired Trawl Sweep Comparison Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In the spring of 2009, Northeast Fisheries Science Center (NEFSC) replaced the previous standard bottom trawl gear (Yankee 36) with a new standard survey trawl...

  13. Integer-valued trawl processes

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Lunde, Asger; Shephard, Neil;

    2014-01-01

    This paper introduces a new continuous-time framework for modelling serially correlated count and integer-valued data. The key component in our new model is the class of integer-valued trawl processes, which are serially correlated, stationary, infinitely divisible processes. We analyse the proba......This paper introduces a new continuous-time framework for modelling serially correlated count and integer-valued data. The key component in our new model is the class of integer-valued trawl processes, which are serially correlated, stationary, infinitely divisible processes. We analyse...

  14. Use of a fishery-independent trawl survey to evaluate distribution patterns of subadult sharks in Georgia

    Science.gov (United States)

    Belcher, C.N.; Jennings, Cecil A.

    2009-01-01

    We investigated the utility of a fishery-independent trawl survey for assessing a potential multispecies shark nursery in Georgia's nearshore and inshore waters. A total of 234 subadult sharks from six species were captured during 85 of 216 trawls. Catch rates and size distributions for subadult sharks and the ratio of neonates to juveniles were consistent among areas. The highest concentrations of subadult sharks occurred in creeks and sounds. Species composition varied among areas. The Atlantic sharpnose shark Rhizoprionodon terraenovae was the most abundant species in sound and nearshore stations, whereas the bonnethead Sphyrna tiburo was the most abundant species in creeks. The aggregate of other species occurred with higher frequency in the sounds and nearshore. Sampling characteristics of the trawl survey were compared with those from a fishery-independent longline survey of subadult sharks to assess the similarity of the two gears. A total of 193 subadult sharks from seven species were captured during 57 of 96 longline sets, whereas 52 subadults from four species were captured during 20 of 48 trawls. Selectivity and efficiency differed between the two gears. The trawl had lower catch rates, caught smaller sharks, and encountered a different suite of species than the longline. General seasonal trends in relative abundance also differed between the two gears; the longline showed an increasing trend in abundance, whereas the trawl showed a stable trend. Although trawls were not found to be efficient for sampling subadult sharks from most species, they can be a useful source of supplemental data.

  15. Obsolete - AFSC/RACE/Eco-FOCI: 2010 Eastern Bering Sea Juvenile Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data collected on this cruise included the following: We conducted a juvenile fish and benthic fish prey survery in the eastern Bering Sea (61 3-meter beam trawls,...

  16. AFSC/RACE/EcoFOCI: 2010 Eastern Bering Sea Juvenile Survey - 1MF10

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data collected on this cruise included the following: We conducted a juvenile fish and benthic fish prey survery in the eastern Bering Sea (61 3-meter beam trawls,...

  17. Anadromous salmonids in the Delta: New science 2006–2016

    Science.gov (United States)

    Perry, Russell W.; Buchanan, Rebecca A.; Brandes, Patricia L.; Burau, Jon R.; Israel, Joshua A

    2016-01-01

    As juvenile salmon enter the Sacramento–SanJoaquin River Delta (“the Delta”) they disperse among its complex channel network where they are subject to channel-specific processes that affect their rate of migration, vulnerability to predation, feeding success, growth rates, and ultimately, survival. In the decades before 2006, tools available to quantify growth, dispersal, and survival of juvenile salmon in this complex channel network were limited.Fortunately, thanks to technological advances such as acoustic telemetry and chemical and structural otolith analysis, much has been learned over the past decade about the role of the Delta in the life cycle of juvenile salmon. Here, we review new science between 2006and 2016 that sheds light on how different life stages and runs of juvenile salmon grow, move, and survive in the complex channel network of the Delta. One of the most important advances during the past decade has been the widespread adoption of acoustic telemetry techniques. Use of telemetry has shed light on how survival varies among alternative migration routes and the proportion of fish that use each migration route. Chemical and structural analysis of otoliths has provided insights about when juveniles left their natal river and provided evidence of extended rearing in the brackish or saltwater regions of the Delta. New advancements in genetics now allow individuals captured by trawls to be assigned to specific runs. Detailed information about movement and survival in the Delta has spurred development of agent-based models of juvenile salmon that are coupled to hydrodynamic models. Although much has been learned, knowledge gaps remain about how very small juvenile salmon (fry and parr) use the Delta. Understanding how all life stages of juvenile salmon grow, rear, and survive in the Delta is critical for devising management strategies that support a diversity of life history strategies.

  18. Efecto del uso de paneles de escape de malla cuadrada sobre la reducción de peces juveniles en la pesquería de arrastre de merluza común (Merluccius gayi gayi Effect of the use of square mesh escape panels on the reduction of young fish in the common hake (Merluccius gayi gayi trawl fishery

    Directory of Open Access Journals (Sweden)

    Dante Queirolo

    2008-01-01

    Full Text Available La evaluación de paneles de escape de malla cuadrada en redes de arrastre de fondo usadas en la pesquería de merluza común se realizó empleando dos metodologías complementarias: lances con sobrecopo y lances alternados. Los lances con sobrecopo permitieron cuantificar la fracción de la captura que escapa a través de los paneles de escape, y determinar la estructura de tallas y pesos medios, estimando longitudes de retención y rangos de selección. Se determinó la fracción bajo 30 y 36 cm de longitud total presentes en el copo y en el sobrecopo, ambos como indicadores del efecto selectivo que éstas producen. Los lances alternados permitieron verificar la disminución de los rendimientos de captura, tanto en número como en peso, aumentando los pesos medios de los ejemplares retenidos y disminuyendo la proporción de ejemplares bajo tallas de referencia, lo que indica la existencia de un efecto de escape en la fracción juvenil del stock.The evaluation of square mesh escape panels in bottom trawl nets used in the common hake fishery was carried out employing two complementary methodologies: top cover and alternated hauls. The top cover hauls were used to quantify the fraction of the catch that escapes through the panels and to determine the size structure and mean weight of the catch, estimating the retention sizes and selection ranges. The fractions under 30 and 36 cm of total length present in the codend and in the top cover were determined as proxies for the selective effect produced by the escape panels. The alternated hauls were used to verify the decrease in the catch rate, both in number and in weight, increasing the mean weight of the retained catch and decreasing the proportion under the reference length, for which we concluded that an escape effect does occur on the young fraction of the stock.

  19. CPS Trawl Life History Length Frequency Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Length distribution of a subset of individuals from a species (mainly non-target) caught during SWFSC-FRD fishery independent trawl surveys of coastal pelagic...

  20. Density dependent catchability in bottom trawl surveys

    OpenAIRE

    Aglen, Asgeir; Engås, Arill; Godø, Olav Rune; McCallum, Barry R.; Stansbury, Don; Walsh, Stephen J.

    1997-01-01

    Fish form schools, layer or patches in which the individual fish's behaviour is not independent of its neighbours movements. On the other hand, at low densities fish may have the freedom to act as single individuals independently of what other fish are doing. Potentially, if these contrasts occur in nature, they may give rise to behavioural differences of fish in front of the trawl at high and low densities with successive effects on catchability and bottom trawl indices of stock ...

  1. JUVENILE COHO SALMON GROWTH AND SURVIVAL ACROSS STREAM NETWORK SEASONAL HABITATS

    Science.gov (United States)

    Understanding watershed-scale variation in juvenile salmonid survival and growth can provide insights into factors influencing demographics and can help target restoration and mitigation efforts for imperiled fish populations. We assessed growth, movement, and apparent overwinte...

  2. 50 CFR 660.130 - Trawl fishery-management measures.

    Science.gov (United States)

    2010-10-01

    ... Figure 1 of part 660, subpart D. (ii) (6) Midwater (or pelagic) trawl gear. Midwater trawl gear must have... Luis, East San Lucia Bank, Point Conception, Hidden Reef/Kidney Bank (within Cowcod Conservation...

  3. Juvenile angiofibroma

    Science.gov (United States)

    Nasal tumor; Angiofibroma - juvenile; Benign nasal tumor; Juvenile nasal angiofibroma; JNA ... Juvenile angiofibroma is not very common. It is most often found in adolescent boys. The tumor contains ...

  4. Residence Times of Juvenile Salmon and Steelhead in Off-Channel Tidal Freshwater Habitats, Columbia River, USA

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Gary E.; Ploskey, Gene R.; Sather, Nichole K.; Teel, D. J.

    2015-05-01

    We estimated seasonal residence times of acoustic-tagged juvenile salmonids in off-channel, tidal freshwater habitats of the Columbia River near the Sandy River delta (rkm 198; 2007, 2008, 2010, and 2011) and Cottonwood Island (rkm 112; 2012).

  5. Net escapement of Antartic krill in trawls

    DEFF Research Database (Denmark)

    Krafft, B.A.; Krag, Ludvig Ahm; Herrmann, Bent;

    This document describes the aims and methodology of a three year project (commenced in 2012) entitled Net Escapement of Antarctic krill in Trawls (NEAT). The study will include a morphology based mathematical modeling (FISHSELECT) of different sex and maturity groups of Antarctic krill (Euphausia...

  6. Understanding the release efficiency of Atlantic cod (Gadus morhua) from trawls with a square mesh panel: effects of panel area, panel position, and stimulation of escape response

    DEFF Research Database (Denmark)

    Herrmann, Bent; Wienbeck, Harald; Karlsen, Junita Diana

    2015-01-01

    Based on size selectivity data for more than 25 000 cod (Gadus morhua) collected during experimental trawl fishing with six different codends, all of which included a square mesh panel,we investigated the effect on cod-release efficiency based on the size of the square mesh panel area, position...... of the square mesh panel, and stimulation of the escape response. Based on the results, we were able to explain why the BACOMAcodend, applied in the Baltic Sea cod directed trawl fishery, releases juvenile cod efficiently, whereas other designs, including a squaremesh panel with similar mesh size, are less...... efficient. Our main findings reveal that the release efficiency of the square mesh panel in the BACOMA codend depends largely on the overlap of the square mesh panel and the catch-accumulation zone in the codend, where cod do not have the option of just drifting further back in the trawl when proximate...

  7. Elwha genetics - Elwha river salmonid genetics

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Elwha Dam is in the process of being removed, with fish restoration to occur in areas previously inaccessible to salmonids. Fish recovery anticipates that...

  8. Bottom-trawling along submarine canyons impacts deep sedimentary regimes

    Science.gov (United States)

    Paradis, Sarah; Puig, Pere; Masqué, Pere; Juan-Díaz, Xènia; Martín, Jacobo; Palanques, Albert

    2017-01-01

    Many studies highlight that fish trawling activities cause seafloor erosion, but the assessment of the remobilization of surface sediments and its relocation is still not well documented. These impacts were examined along the flanks and axes of three headless submarine canyons incised on the Barcelona continental margin, where trawling fleets have been operating for decades. Trawled grounds along canyon flanks presented eroded and highly reworked surface sediments resulting from the passage of heavy trawling gear. Sedimentation rates on the upper canyon axes tripled and quadrupled its natural (i.e. pre-industrialization) values after a substantial increase in total horsepower of the operating trawling fleets between 1960 s and 1970 s. These impacts affected the upper canyon reaches next to fishing grounds, where sediment resuspended by trawling can be transported towards the canyon axes. This study highlights that bottom trawling has the capacity to alter natural sedimentary environments by promoting sediment-starved canyon flanks, and by enhancing sedimentation rates along the contiguous axes, independently of canyons’ morphology. Considering the global mechanisation and offshore expansion of bottom trawling fisheries since the mid-20th century, these sedimentary alterations may occur in many trawled canyons worldwide, with further ecological impacts on the trophic status of these non-resilient benthic communities. PMID:28233856

  9. Basin-Scale Variation in the Spatial Pattern of Fall Movement of Juvenile Coho Salmon in the West Fork Smith River, Oregon

    Science.gov (United States)

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

  10. Dermatomyositis (Juvenile)

    Science.gov (United States)

    ... Am A Patient / Caregiver Diseases & Conditions Dermatomyositis (Juvenile) Dermatomyositis (Juvenile) Fast Facts Patients with JDM have varying ... What are common signs and symptoms of juvenile dermatomyositis? The most common signs and symptoms of JDM ...

  11. Retinoschisis (Juvenile)

    Science.gov (United States)

    ... here Home › Eye Conditions Listen Retinoschisis What is Juvenile Retinoschisis? Juvenile retinoschisis is an inherited disease diagnosed in childhood ... degeneration of the retina. What are the symptoms? Juvenile retinoschisis, also known as X-linked retinoschisis, occurs ...

  12. BIOCHEMICAL AND MORPHOMETRIC PARAMETERS OF PRE-LARVAE OF THREE SALMONIDS SPECIES AT ONE-DAY AGE

    OpenAIRE

    Ye. Barylo

    2016-01-01

    Purpose. To study and analyze the morphometric and some biochemical parameters of pre-larval brown trout, rainbow trout and brook trout in post-embryonic period under the conditions of "Rybnyi Potik” farm in the Transcarpathian region for further use of the obtained data in scientific and practical works related to the cultivation of the juveniles of valuable salmonid species. Methodology. One-day free embryos (pre-larvae) of brown trout, rainbow trout and brook trout we used as study mat...

  13. Next-generation salmonid alphavirus vaccine development

    NARCIS (Netherlands)

    Hikke, M.C.

    2016-01-01

    ABSTRACT Aquaculture is essential to meet the current and future demands for seafood to feed the world population. Atlantic salmon and rainbow trout are two of the most cultured aquaculture species. A pathogen that threatens these species is salmonid alphavirus (SAV). A current inactivated virus vac

  14. Some myxosporidia found in Pacific Northwest salmonids

    Science.gov (United States)

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

    1957-01-01

    During the histological examination of a group of wild and hatchery salmonids undescribed sporazoans were frequently observed. This was not unexpected, since Myxosporidia are typical fish parasites (Kudo, 1920). Myxidium were observed in kidney tubules, Cholromyxum in glomeruli, and Myxobous in the spinal cord and on epidermal scales. The present paper will deal with the description and indentification of these unclassified Myxosporodia.

  15. Next-generation salmonid alphavirus vaccine development

    NARCIS (Netherlands)

    Hikke, M.C.

    2016-01-01

    ABSTRACT Aquaculture is essential to meet the current and future demands for seafood to feed the world population. Atlantic salmon and rainbow trout are two of the most cultured aquaculture species. A pathogen that threatens these species is salmonid alphavirus (SAV). A current inactivated virus

  16. Juvenile Scleroderma

    Science.gov (United States)

    Juvenile Scleroderma INTRODUCTION Every parent will experience a moment of panic when told their child has scleroderma. ... in all their family members as well. CONCLUSION Juvenile scleroderma can be unsettling for the child and ...

  17. Size selectivity and trawling efficiency of two sampling trawls used in resource surveys of yellowtail flounder on Grand Bank, NAFO Div. 3LNO

    National Research Council Canada - National Science Library

    Walsh, S.J; McCallum, B.R

    1998-01-01

    .... Size selectivity and trawl efficiency of two shrimp trawls used in the surveys of the Grand Bank yellowtail flounder, Pleuronectes ferruginea, were analyzed from a series of comparative fishing tows...

  18. Application of neural networks to prediction of fish diversity and salmonid production in the Lake Ontario basin

    Science.gov (United States)

    McKenna, James E.

    2005-01-01

    Diversity and fish productivity are important measures of the health and status of aquatic systems. Being able to predict the values of these indices as a function of environmental variables would be valuable to management. Diversity and productivity have been related to environmental conditions by multiple linear regression and discriminant analysis, but such methods have several shortcomings. In an effort to predict fish species diversity and estimate salmonid production for streams in the eastern basin of Lake Ontario, I constructed neural networks and trained them on a data set containing abiotic information and either fish diversity or juvenile salmonid abundance. Twenty percent of the original data were retained as a test data set and used in the training. The ability to extend these neural networks to conditions throughout the streams was tested with data not involved in the network training. The resulting neural networks were able to predict the number of salmonids with more than 84% accuracy and diversity with more than 73% accuracy, which was far superior to the performance of multiple regression. The networks also identified the environmental variables with the greatest predictive power, namely, those describing water movement, stream size, and water chemistry. Thirteen input variables were used to predict diversity and 17 to predict salmonid abundance.

  19. Utilization of seagrass habitats by juvenile groupers and snappers in Banten Bay, Banten Province, Indonesia

    NARCIS (Netherlands)

    Nuraini, S.; Carballo, E.C.; Densen, van W.L.T.; Machiels, M.A.M.; Lindeboom, H.J.; Nagelkerke, L.A.J.

    2007-01-01

    Coastal development in Banten Bay, Indonesia, decreased seagrass coverage to only 1.5% of its surface area. We investigated the importance of seagrass as habitat for juvenile groupers (Serranidae) and snappers (Lutjanidae), by performing beam trawl hauls on a weekly basis in two seagrass locations a

  20. Gear Selectivity of a Longfin Squid Bottom Trawl

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Loligo pealeii (longfin inshore squid) co-occurs with Atlantic butterfish (Peprilus triacanthus) throughout the year and discarding in the L. pealeii bottom trawl...

  1. Corpus Christi EFH Trawling Effects 2001-2002

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — We compared sediments and benthos of two adjacent zones of the middle Texas coast, one of which was closed to shrimp trawling for 7 months. Findings indicated that...

  2. NEFSC 2012 Spring Bottom Trawl Survey (HB1201, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  3. NEFSC 2014 Fall Bottom Trawl Survey (HB1405, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  4. NEFSC 2008 Fall Bottom Trawl Survey (HB0807, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  5. NEFSC 2009 Fall Bottom Trawl Survey (HB0905, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  6. NEFSC 2013 Fall Bottom Trawl Survey (HB1304, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  7. NEFSC 2002 Fall Bottom Trawl Survey (AL0210, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  8. NEFSC 2003 Fall Bottom Trawl Survey (AL0305, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  9. NEFSC 2005 Spring Bottom Trawl Survey (AL0504, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  10. NEFSC 2004 Winter Bottom Trawl Survey (AL0401, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  11. NEFSC 2004 Spring Bottom Trawl Survey (AL0403, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  12. NEFSC 1999 Fall Bottom Trawl Survey (AL9911, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  13. NEFSC 2005 Fall Bottom Trawl Survey (AL0509, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  14. NEFSC 2004 Fall Bottom Trawl Survey (AL0409, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  15. NEFSC 2015 Spring Bottom Trawl Survey (HB1501, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  16. NEFSC 2001 Fall Bottom Trawl Survey (AL0110, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  17. NEFSC 2012 Fall Bottom Trawl Survey (HB1206, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  18. NEFSC 2002 Winter Bottom Trawl Survey (AL0203, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  19. NEFSC 2008 Spring Bottom Trawl Survey (HB0802, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  20. NEFSC 2014 Spring Bottom Trawl Survey (HB1401, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  1. NEFSC 2008 Spring Bottom Trawl Survey (AL0801, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  2. NEFSC 2009 Spring Bottom Trawl Survey (HB0901, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  3. NEFSC 2005 Fall Bottom Trawl Survey (AL0508, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  4. NEFSC 1998 Fall Bottom Trawl Survey (AL9811, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  5. NEFSC 2007 Bottom Trawl Survey Calibration (HB0710, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  6. 77 FR 29586 - Sea Turtle Conservation; Shrimp Trawling Requirements; Correction

    Science.gov (United States)

    2012-05-18

    ... Part 223 RIN 0648-BC10 Sea Turtle Conservation; Shrimp Trawling Requirements; Correction AGENCY... turtle excluder devices (TEDs) in their nets, and announced five public hearings to be held in...

  7. NEFSC 2000 Fall Bottom Trawl Survey (AL0007, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  8. NEFSC 2002 Spring Bottom Trawl Survey (AL0204, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  9. NEFSC 2011 Spring Bottom Trawl Survey (HB1102, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  10. NEFSC 2011 Fall Bottom Trawl Survey (HB1105, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  11. NEFSC 2008 Fall Bottom Trawl Survey (AL0803, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  12. NEFSC 2005 Winter Bottom Trawl Survey (AL0502, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  13. Bottom Trawl Survey Protocol Development (HB0706, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Cruise objectives include: 1) Investigate performance characteristics of new research bottom trawl; 2) Develop standard operating procedures for the NEFSC Bottom...

  14. NEFSC 2013 Spring Bottom Trawl Survey (HB1301, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  15. NEFSC 2015 Fall Bottom Trawl Survey (HB1506, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  16. NEFSC 2007 Bottom Trawl Survey Calibration (HB0711, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  17. NEFSC 2000 Fall Bottom Trawl Survey (Al0006, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  18. NEFSC 2010 Spring Bottom Trawl Survey (HB1002, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  19. NEFSC 2003 Spring Bottom Trawl Survey (DE0303, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  20. West Coast Groundfish Bottom Trawl Survey Data - Annual West Coast time series groundfish trawl data collection survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Members of the Fishery Resource Analysis and Monitoring Division Survey Team conduct an annual West Coast Groundfish Bottom Trawl Survey from May - October each...

  1. Improving fishing effort descriptors: Modelling engine power and gear-size relations of five European trawl fleets

    DEFF Research Database (Denmark)

    Eigaard, Ole Ritzau; Rihan, Dominic; Graham, Norman

    2011-01-01

    Based on information from an international inventory of gears currently deployed by trawlers in five European countries, the relationship between vessel engine power and trawl size is quantified for different trawl types, trawling techniques and target species. Using multiplicative modelling...

  2. Demonstration of the salmonid humoral response to Renibacterium salmoninarum using a monoclonal antibody against salmonid immunoglobulin

    Science.gov (United States)

    Bartholomew, J.L.; Arkoosh , M.R.; Rohovec, J.S.

    1991-01-01

    The specificity of the antibody response of salmonids to Renibacterium salmoninarum antigens was demonstrated by western blotting techniques that utilized a monoclonal antibody against salmonid immunoglobulin. In this study, the specificity of the response in immunized chinook salmon Oncorhynchus tshawytschawas compared with the response in naturally infected chinook salmon and coho salmon O. kisutch, and immunized rabbits. The antibody response in immunized salmon and rabbits and the naturally infected fish was primarily against the 57–58kilodalton protein complex. In addition to recognizing these proteins in the extracellular fraction and whole-cell preparations, antibody from the immunized salmon and rabbits detected four proteins with lower molecular masses. Western blotting techniques allow identification of the specific antigens recognized and are a useful tool for comparing the immunogenicity of different R. salmoninarumpreparations. Immunofluorescent techniques with whole bacteria were less sensitive than western blotting in detecting salmonid anti-R. salmoninarumantibody.

  3. Habitat suitability for juvenile common sole ( Solea solea, L.) in the Bay of Biscay (France): A quantitative description using indicators based on epibenthic fauna

    Science.gov (United States)

    Le Pape, Olivier; Baulier, Loîc; Cloarec, Aurélie; Martin, Jocelyne; Le Loc'h, François; Désaunay, Yves

    2007-02-01

    This study describes the spatial distribution of young-of-the-year common sole based on beam trawl surveys conducted in late summer in the coastal and estuarine parts of the Bay of Biscay (France). Previous studies showed that habitat suitability for juvenile common sole varies according to physical factors and notably bathymetry and sediment structure. Nevertheless, the use of these descriptors alone to model habitat suitability led to considerable unexplained variability in juvenile common sole distribution. Hence, the epibenthic macro- and megafauna collected during beam trawl surveys was taken into account to improve models of habitat suitability for these juvenile flatfish. Ecotrophic guilds based on life traits (behaviour, mobility and feeding) were used to develop generic indicators of trawled benthic fauna. These synthetic descriptors were used in generalized linear models of habitat suitability in order to characterize the distribution of juvenile common sole. This approach significantly improved the description based on physical descriptors and allowed demonstrating that young common sole distribution is related to the density of trawled deposit and suspension feeders and also of carnivorous organisms. These models provide a reliable method to develop indicators of nursery habitat suitability from trawl survey data with the aim of assessing and surveying their quality.

  4. Juvenile Judge

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    SHANG Xiuyun was among the first sitting judges when the juvenile court was set up in Beijing 10 years ago. With enriched experience she has altered the way judges ask questions in court. She began the practice of inviting juvenile offenders, their parents, relatives, friends and teachers to the juvenile court to work hand in hand in dealing with cases: Facing their relatives and friends and hearing their heartfelt words, juvenile offenders would often be touched, thus bringing forth a positive attitude toward life.

  5. Effects of trawl selectivity and genetic parameters on fish body length under long-term trawling

    Science.gov (United States)

    Yu, Yang; Sun, Peng; Cui, He; Sheng, Huaxiang; Zhao, Fenfang; Tang, Yanli; Chen, Zelin

    2015-10-01

    Long-term fishing pressure affects the biological characteristics of exploited fish stocks. The biological characteristics of hairtail ( Trichiurus lepturus) in the East China Sea are unable to recover because of long-term trawling. Fishing induces evolutionary effects on the fish's biological characteristics. Evidence of these changes includes small size at age, a shift to earlier age structure, and early maturation. Natural and artificial selection usually affect the fish's life history. Selection can induce different chances of reproduction, and individual fish can give a different genetic contribution to the next generation. In this study, analysis of time-dependent probability of significance and test of sensitivity were used to explore the effects of fish exploitation rate, mesh size, and heritability with long-term trawling. Results showed that fishing parameters were important drivers to exploited fish population. However, genetic traits altered by fishing were slow, and the changes in biological characteristics were weaker than those caused by fishing selection. Exploitation rate and mesh size exhibited similar evolutionary trend tendency under long-term fishing. The time-dependent probability of significance trend showed a gradual growth and tended to be stable. Therefore, the direction of fishing-induced evolution and successful management of fish species require considerable attention to contribute to sustainable fisheries in China.

  6. 2013 Small Pelagics Acoustic/Trawl Survey (PC1306, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Objectives of the 2013 Small Pelagics Acoustic/Trawl Survey were to sample the northern Gulf of Mexico with a 90-ft high opening trawl to facilitate assessments of...

  7. 2013 Small Pelagics Acoustic/Trawl Survey (PC1306, ME70)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Objectives of the 2013 Small Pelagics Acoustic/Trawl Survey were to sample the northern Gulf of Mexico with a 90-ft high opening trawl to facilitate assessments of...

  8. AFSC/ABL: Frederick Sound Echo-integrated Trawl Survey, 2001 to 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The acoustic trawl database for Frederick Sounds echo-trawl survey was conducted from 2001 to 2004. The surveys were conducted throughout most of the southern part...

  9. Modified Herring Trawl Fish Catch Data, Gulf of Alaska Fjords, 2004-2011

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains catch data from trawls at the sampling stations. We deployed a modified herring trawl in coastal waters within glacier fjords of Alaska....

  10. AFSC/ABL: Lynn Canal Echo-Integrated Trawl Surveys, 2001-2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The acoustic trawl database for Lynn Canals echo-trawl survey was conducted from 2001 to 2004 throughout southern Lynn Canal in southeast Alaska. Acoustic surveys...

  11. Fish assemblages in southern California using trawl data from the National Marine Fisheries Service

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish benthic trawls were completed by the National Marine Fisheries Service Groundfish Survey Program (NMFS GSP). Data from 477 fishery independent trawls ranging...

  12. 50 CFR 660.381 - Limited entry trawl fishery management measures.

    Science.gov (United States)

    2010-10-01

    ... Figure 1 of part 660, subpart G. (ii) (6) Midwater (or pelagic) trawl gear. Midwater trawl gear must have..., Point Sur Deep, Big Sur Coast/Port San Luis, East San Lucia Bank, Point Conception, Hidden...

  13. Size selection of Antarctic krill (Euphausia superba) in trawls.

    Science.gov (United States)

    Krag, Ludvig A; Herrmann, Bent; Iversen, Svein A; Engås, Arill; Nordrum, Sigve; Krafft, Bjørn A

    2014-01-01

    Trawlers involved in the Antarctic krill (Euphausia superba) fishery use different trawl designs, and very little is known about the size selectivity of the various gears. Size selectivity quantifies a given trawl's ability to catch different sizes of a harvested entity, and this information is crucial for the management of a sustainable fishery. We established a morphological description of krill and used it in a mathematical model (FISHSELECT) to predict the selective potential of diamond meshes measuring 5-40 mm with mesh opening angles (oa) ranging from 10 to 90°. We expected the majority of krill to encounter the trawl netting in random orientations due to high towing speeds and the assumed swimming capabilities of krill. However, our results indicated that size selectivity of krill is a well-defined process in which individuals encounter meshes at an optimal orientation for escapement. The simulation-based results were supported by data from experimental trawl hauls and underwater video images of the mesh geometry during fishing. Herein we present predictions for the size selectivity of a range of netting configurations relevant to the krill fishery. The methods developed and results described are important tools for selecting optimal trawl designs for krill fishing.

  14. Influences of Stocking Salmon Carcass Analogs on Salmonids in Yakima River Tributaries, 2001-2002 Technical Report.

    Energy Technology Data Exchange (ETDEWEB)

    Pearsons, Todd N.; Johnson, Christopher L. (Washington Department of Fish and Wildlife, Olympia, WA)

    2003-04-01

    The benefits that marine derived nutrients from adult salmon carcasses provide to juvenile salmonids are increasingly being recognized. Current estimates suggest that only 6-7% of marine-derived nitrogen and phosphorus that were historically available to salmonids in the Pacific Northwest are currently available. Food limitation may be a major constraint limiting the restoration of salmonids. A variety of methods have been proposed to offset this nutrient deficit including: allowing greater salmon spawning escapement, stocking hatchery salmon carcasses, and stocking inorganic nutrients. Unfortunately, each of these methods has some ecological or socio-economic shortcoming. We intend to overcome many of these shortcomings by making and evaluating a pathogen free product that simulates a salmon carcass (analog). Abundant sources of marine derived nutrients are available such as fish offal from commercial fishing and salmon carcasses from hatcheries. However, a method for recycling these nutrients into a pathogen free analog that degrades at a similar rate as a natural salmon carcass has never been developed. We endeavored to (1) develop a salmon carcass analog that will increase the food available to salmonids, (2) determine the pathways that salmonids use to acquire food from analogs, and (3) determine the benefits to salmonids and the potential for application to salmonid restoration. We used a before-after-control-impact-paired design in six tributaries of the upper Yakima basin to determine the utility of stocking carcass analogs. Our preliminary results suggest that the introduction of carcass analogs into food-limited streams can be used to restore food pathways previously provided by anadromous salmon. The analogs probably reproduced both of the major food pathways that salmon carcasses produce: direct consumption and food chain enhancement. Trout and salmon fed directly on the carcass analogs during the late summer and presumably benefited from the increased

  15. Effectiveness of a redesigned water diversion using rock vortex weirs to enhance longitudinal connectivity for small Salmonids

    Science.gov (United States)

    Martens, Kyle D.; Connolly, Patrick J.

    2010-01-01

    For nearly 100 years, water diversions have affected fish passage in Beaver Creek, a tributary of the lower Methow River in north-central Washington State. From 2000 to 2004, four dam-style water diversions were replaced with a series of rock vortex weirs (RVWs). The weirs were designed to allow fish passage while maintaining the ability to divert water into irrigation canals. We observed the new appearance of three species (juvenile Chinook salmon Oncorhynchus tshawytscha, juvenile coho salmon O. kisutch, and mountain whitefish Prosopium williamsoni) upstream of the RVWs, indicating successful restoration of longitudinal connectivity. We used passive integrated transponder (PIT) tags and instream PIT tag interrogation systems during 2004–2007 to evaluate upstream passage of small salmonids (<240 mm fork length) through one series of RVWs. We documented 109 upstream passage events by small salmonids through the series of RVWs; most of the events (81%) involved passage of rainbow trout O. mykiss or juvenile steelhead (anadromous rainbow trout). Small rainbow trout or steelhead ranging from 86 to 238 mm (adjusted fork length) were able to pass upstream through the RVWs, although a delay in fish passage at discharges below 0.32 m3/s was detected in comparison with nearby control sections.

  16. Catchability of pelagic trawls for sampling deep-living nekton in the mid-North Atlantic

    OpenAIRE

    2011-01-01

    We use the material collected in summer 2004 from the Mid-Atlantic Ridge between Iceland the Azores with three pelagic trawls to estimate relative catchabilities for the common fish, cephalopod, decapod and jellyfish species. Catchability is defined as the ratio of numbers or weight caught between two trawls, standardised for towed distance. We estimate taxon-specific catchability coefficients for two large pelagic trawls with graded meshes, using a smaller pelagic trawl with uniform mesh siz...

  17. Juvenile Arthritis

    Science.gov (United States)

    Juvenile arthritis (JA) is arthritis that happens in children. It causes joint swelling, pain, stiffness, and loss of motion. It can affect any joint, but ... of JA that children get is juvenile idiopathic arthritis. There are several other forms of arthritis affecting ...

  18. Impact of bottom trawling on sediment characteristics - A study along inshore waters off Veraval coast, India

    Digital Repository Service at National Institute of Oceanography (India)

    Bhagirathan, U.; Meenakumari, B.; Jayalakshmy, K.V.; Panda, S.K.; Madhu, V.R.; Vaghela, D

    of water depths 15-20 m, 21-25 m, 26-30 m, 31-35 m and 36-40 m in commercial trawling grounds. Trawling was conducted for 12 months in a span of 15 months (September 2005-November 2006) excluding the trawl ban period (June to August). The sediment texture...

  19. [Juvenile scleroderma].

    Science.gov (United States)

    de Mâcedo, Patrícia Andrade; Shinjo, Samuel Katsuyuki; Goldenstein-Schainberg, Cláudia

    2008-01-01

    Juvenile scleroderma is a rare childhood condition characterized by fibrosis of the skin and internal organs. Clinical manifestations of childhood scleroderma are different from adult disease and early recognition, correct classification and treatment can improve long-term outcome. This review explores the most recent actualizations on clinical manifestations, classification criteria, treatment options and prognosis of juvenile scleroderma. There are two main forms of the disease: localized scleroderma and systemic sclerosis. Localized scleroderma is the most common form in children and mostly restricted to the skin. Juvenile diffuse systemic sclerosis is related to visceral involvement and cardiac disease which is the main cause of death in these patients. The outcome of juvenile systemic sclerosis is better compared with the adult form. Treatment remains a medical challenge and the EULAR task force proposed an approach to juvenile scleroderma treatment based on expert's opinion and guidelines used for the treatment of adults. Larger studies on childhood scleroderma are warranted.

  20. Zooplankton Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  1. CTD Oceanographic Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  2. Impact and distribution of bottom trawl fishing on mud-bottom communities in the Kattegat

    DEFF Research Database (Denmark)

    Pommer, Christina Dahl; Olesen, Michael; Hansen, Jorgen L. S.

    2016-01-01

    of trawled area demonstrated that the habitats are nearly 100% impacted, and frequencies of trawling beneath 100 m depth can reach 20 events per year. Multivariate analysis of community composition could not discriminate between lightly trawled and heavily trawled areas. However, a strong habitat selectivity...... to areas with higher activity. Thus, the Kattegat has been impacted to an extent where areas with reference conditions for certain habitats below 22 m no longer exist. Consequently, it is unknown how the benthic communities would have appeared without trawl disturbance and, thus, difficult to determine...

  3. KEMAMPUAN TANGKAP JARING TRAWL TERHADAP IKAN DEMERSAL DI PERAIRAN TARAKAN DAN SEKITARNYA

    Directory of Open Access Journals (Sweden)

    Asep Priatna

    2016-03-01

    Fish stock estimation is very important information as basis for developing fisheries. Until now, estimation of demersal fish stock is usually used swept area method by using trawl net fishing. However, there was the problem related to accuracy of fish abundant estimation that is how much the demersal fish could be accurately caught by the trawl net. To solve this problem, an approach estimation of dmersal fish stock using acoustic survey conducted simultaneously with demersal trawl fishing. Research activities were conducted on May, August and November 2012 in Tarakan waters, North Kalimantan using echosounder Simrad EY60-120 kHz and bottom trawl net with 26 m headrope. The result show that the catchability coefficient of trawl net estimated  0,3, it means that the trawl net could be able to catch 30% of demersal fish during swept area trawl fishing.

  4. Juvenile Prostitution.

    Science.gov (United States)

    Csapo, Marg

    1986-01-01

    Recent research and Canadian government committee reports concerning juvenile prostitution are reviewed. Proposals are made in the realms of law and social policy; and existing programs are described. (DB)

  5. Juvenile Prostitution.

    Science.gov (United States)

    Csapo, Marg

    1986-01-01

    Recent research and Canadian government committee reports concerning juvenile prostitution are reviewed. Proposals are made in the realms of law and social policy; and existing programs are described. (DB)

  6. Job Satisfaction in the Shrimp Trawl Fisheries of Vietnam

    Science.gov (United States)

    Sinh, Le Xuan

    2012-01-01

    This paper investigates the job satisfaction of small-scale shrimp trawl fishers in the vicinity of Camau National Park in southern Vietnam. The research sample consisted of 77 fishers who belong to a growing population of shrimp fishers in the region. The results suggest that 60% would change their fishing metier, 78% would leave fishing for…

  7. Job Satisfaction in the Shrimp Trawl Fisheries of Chennai, India

    Science.gov (United States)

    Bavinck, Maarten

    2012-01-01

    Shrimp trawling represents an important fishing metier in South India, generating high levels of employment and economic value. It is also a contested metier, ostensibly contributing to environmental degradation and social inequality. This paper investigates the job satisfaction of crew members (captains and workers) on board the shrimp trawlers…

  8. Juvenile myasthenia

    Directory of Open Access Journals (Sweden)

    Knežević-Pogančev Marija

    2011-01-01

    Full Text Available Introduction. Juvenile myasthenia is a chronic autoimmune neuromuscular disease characterized by varying degrees of fluctuating, painless muscle weakness and rapid fatigue of any muscles under voluntary control. Juvenile myasthenia is a form of myasthenia appearing in adolescent age, representing 10% to 15% of all cases of myasthenia gravis. Juvenile myasthenia is presented by a defect in the transmission of nerve impulses to muscles, resulting from a breakdown in the normal communication between nerves and muscles. In myasthenia, antibodies produced by the body’s own immune system block, alter, or destroy the receptors for acetylcholine. Juvenile myasthenia is neither directly inherited nor is it contagious. Signs and Symptoms. The first noticeable symptoms may be eye muscle weakness, difficulty in swallowing, or slurred speech. Juvenile myasthenia usually affects muscles innervated by the cranial nerves (face, lips, tongue, neck and throat, but it can affect any muscle group. Symptoms vary in type and severity with typical periods of exacerbation interspersed with periods of remission. When the muscles necessary for breathing are affected, a patient is said to be in a myasthenic crisis, which is a life-threatening situation. Disease Outcome and Treatment. Juvenile myasthenia produces sporadic but progressive weakness and abnormal fatigability of striated (skeletal muscles, exacerbated by exercise and repeated movement, but improved by rest and anticholinesterase drugs. Juvenile myasthenia follows an unpredictable course of recurring exacerbations and periodic remissions. With current therapies, however, most cases of juvenile myasthenia are not as serious as the name implies. Although there is no known cure, drug treatment has improved prognosis and allows patients to lead relatively normal lives, except during exacerbations.

  9. Epidemiology and Control of Infectious Diseases of Salmonids in the Columbia River Basin, 1986 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Fryer, John L.

    1986-12-01

    The Department of Microbiology at Oregon State University with funding from the Bonneville Power Administration conducted a study relating to the epidemiology and control of three fish diseases of salmonids in the Columbia River Basin. These three diseases were ceratomyxosis caused by the myxosporidan parasite Ceratomyxa Shasta, bacterial kidney disease, the causative agent Renibacterium salmoninarum, and infectious hematopoietic necrosis, caused by a rhabdovirus. Each of these diseases is highly destructive and difficult or impossible to treat with antimicrobial agents. The geographic range of the infectious stage of C. Shasta has been extended to include the Snake River to the Oxbow and Hells Canyon Dams. These are the farthest upriver sites tested. Infections of ceratomyxosis were also initiated in the east fork of the Lewis River and in the Washougal River in Washington. Laboratory studies with this parasite failed to indicate that tubeficids are required in its life cycle. Bacterial kidney disease has been demonstrated in all life stages of salmonids: in the eggs, fry, smolts, juveniles and adults in the ocean, and in fish returning to fresh water. Monoclonal antibodies produced against R. salmoninarum demonstrated antigenic differences among isolates of the bacterium. Monoclonal antibodies also showed antigens of R. salmoninarum which are similar to those of a wide variety of gram positive and gram negative bacteria. A demonstration project at Round Butte Hatchery showed U V treatment to be an effective method for reducing the microbial population of the water supply and could reduce risks of IHNV. Tangential flow filtration was used successfully to concentrate IHNV from environmental water. At Round Butte Hatchery the carrier rate of IHNV in adults was very low and there was no subsequent mortality resulting from IHN in juveniles.

  10. Juvenile idiopathic arthritis

    Science.gov (United States)

    Juvenile rheumatoid arthritis (JRA); Juvenile chronic polyarthritis; Still disease; Juvenile spondyloarthritis ... The cause of juvenile idiopathic arthritis (JIA) is not known. It ... illness . This means the body attacks and destroys healthy body ...

  11. Juvenile Polyposis Syndrome

    Science.gov (United States)

    ... Types of Cancer > Juvenile Polyposis Syndrome Request Permissions Juvenile Polyposis Syndrome Approved by the Cancer.Net Editorial Board , 12/2015 What is juvenile polyposis syndrome? Juvenile polyposis syndrome (JPS) is a ...

  12. Epidemiology and Control of Infectious Diseases of Salmonids in the Columbia River Basin, 1983 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Fryer, John L.

    1984-11-01

    The Department of Microbiology at Oregon State University with funding from the Bonneville Power Administration conducted a study relating to the epidemiology and control of three fish diseases of salmonids in the Columbia River Basin. These three diseases were ceratomyxosis which is caused by the myxosporidan parasite Ceratomyxa shasta, bacterial kidney disease, the etiological agent of which is Renibacterium salmoninarum, and infectious hematopoietic necrosis, which is caused by a rhabdovirus. Each of these diseases is highly destructive and difficult or impossible to treat with antimicrobial agents. The presence of ceratomyxosis in rainbow trout exposed at McNary and Little Goose Dams extends the range of this disease about 200 miles further up the Columbia River and into the Snake River drainage. Wallowa steelhead trout were less resistant to this disease than other upriver stocks tested. Juvenile salmonids entering the Columbia River estuary were collected periodically between May to September, 1983. Nine percent of the beach seined chinook salmon and 5, 11 and 12%, respectively, of the purse seined coho and chinook salmon and steelhead trout were infected with Ceratomyxa shasta. Experiments indicated ceratomyxosis progresses in salt water at the same rate as in fresh water once the fish have become infected. These data indicate a longer exposure to infective stages of C. shasta than previously identified and that approximately 10% of the migrating salmonids are infected and will probably die from this organism after entering salt water. Since sampling began in 1981 the bacterial kidney disease organism, Renibacterium salmoninarum, has been detected by the fluorescent antibody test in seven salmonid species caught in the open ocean off the coasts of Washington and Oregon. The bacterium has been found primarily in chinook salmon (11%) with lesions in 2.5% of these fish. This disease was also detected at levels ranging from 17% in coho salmon to 25% in chinook

  13. Investigations on juvenile fish excluder cum shrimp sorting device (JFE-SSD).

    Science.gov (United States)

    Boopendranath, Menothuparambil Ravunny; Pravin, Puthra; Gibinkumar, Therodath Rajan; Sabu, Sarasan; Madhu, Vettiyattil Ramakrishnan

    2013-12-01

    Penaeid shrimp is a major resource in India contributing about 7.4% of the total marine fish landings. They are mostly landed by small mechanized trawlers. Shrimp trawling generates large quantities of bycatch mostly consisting of juvenile fishes, due to use of small mesh size in codends of trawl nets. Juvenile Fish Excluder cum Shrimp Sorting Device (JFE-SSD) is a bycatch reduction device with an in situ sorting mechanism, which replaces the conventional codend in a trawl. The device was designed to catch shrimps and commercially important fish species using a specially designed oval sorting grid with appropriate bar spacing and dual codends. Shrimp sorting efficiency and bycatch exclusion characteristics of JFE-SSD attached to a 29.6 m shrimp trawl, was tested by experimental fishing along the coastal waters off Cochin, India. Out of a total of 317.07 kg of catch encountered in the JFE-SSD installed trawl, 58.22% was retained in lower codend, 17.53% in upper codend and 24.25%, mostly consisting of juveniles and sub-adults of finfishes and shellfishes, was excluded from upper codend. The mean CPUE registered for upper and lower codend were 7.23±1.04 SE and 5.84±0.96 SE kg h(-1) respectively. The CPUE of shrimps retained in upper and lower codends were significantly different (Kruskal-Wallis test (1,62), P<0.001), but the mean CPUE for fishes did not vary significantly. The average escapement of shrimps and juvenile fishes from upper codend were 0.06±0.02 SE kg h(-1) and 2.40±0.44 SE kg h(-1) respectively. Significant differences in the length composition between upper and lower codends were noticed for Megalaspis cordyla, Stolephorus waitei, Metapenaeus dobsoni and Parapenaeopsis stylifera. The experiments demonstrated in situ sorting ability of the device and its potential to reduce the bycatch of juveniles and sub-adults in shrimp trawls.

  14. Fish bycatch of the laulao catfish Brachyplatystoma vaillantii (Valenciennes, 1840 trawl fishery in the Amazon Estuary

    Directory of Open Access Journals (Sweden)

    Erica Antunes Jimenez

    2013-06-01

    Full Text Available This study aimed to analyse the composition and seasonal variation in the fish bycatch of the Brachyplatystoma vaillantii trawl fishery in the Amazon Estuary in 2009 by monitoring the trips of 48 vessels. The bycatch represented 29% of the catches, totalling 22,228 specimens and 52 taxa, distributed in 22 families (the principal families were Ariidae, Pimelodidae, and Sciaenidae. Brachyplatystoma rousseauxii, Plagioscion squamosissimus, and Sciades herzbergii together contributed 69% of the bycatch and were considered consistent bycatch species. Although a higher proportion of bycatch was captured during the rainy season, the seasonal difference was not significant. A multidimensional scaling (MDS ordination analysis and an analysis of similarity (ANOSIM indicated that the species composition of the bycatch was similar across the seasons. However, larger numbers of B. rousseauxii and P. squamosissimus were captured during the rainy season, whereas S. herzbergii predominated during the dry season. The marine migrants and estuarine species guilds showed the greatest richness, whereas freshwater migrants were the most numerous. Among the feeding guilds, the zoobenthivores were the most diverse, whereas the piscivores were the most abundant. The results indicate that fishing pressure primarily affects small- (20-30 cm and medium-sized (30-50 cm individuals, although the catch of P. squamosissimus was composed primarily of adults. However, the catches of both B. rousseauxii and B. vaillantii were composed primarily of juveniles.

  15. Job Satisfaction in the Shrimp Trawl Fisheries of Chennai, India.

    Science.gov (United States)

    Bavinck, Maarten

    2012-10-01

    Shrimp trawling represents an important fishing métier in South India, generating high levels of employment and economic value. It is also a contested métier, ostensibly contributing to environmental degradation and social inequality. This paper investigates the job satisfaction of crew members (captains and workers) on board the shrimp trawlers of Chennai (former Madras). Research took place in 2007 and 2008 (N = 137). Results suggest a general satisfaction with being in the fishery. However, a little over three-fifths of fishers said they would be willing to change fishing métier and about one-half said they would leave the occupation. About one-half also said they would not advise a young person to enter the occupation. The tendency to move away from the fishery is argued to reflect a growing pessimism about the future of the shrimp trawl fisheries, but also an increasing awareness of other economic opportunities.

  16. Juvenile Spondyloarthritis

    Science.gov (United States)

    Gmuca, Sabrina; Weiss, Pamela F.

    2015-01-01

    Purpose of review To provide a comprehensive update of the pathogenesis, diagnostic imaging, treatments, and disease activity measurements of juvenile spondyloarthritis (JSpA). Recent findings Genetic and microbiome studies have provided new information regarding possible pathogenesis of JSpA. Recent work suggests that children with JSpA have decreased thresholds for pain in comparison to healthy children. Additionally, pain on physical examination and abnormalities on ultrasound of the entheses are not well correlated. Treatment guidelines for juvenile arthritis, including JSpA, were published by the American College of Rheumatology and are based on active joint count and presence of sacroiliitis. Recent studies have established the efficacy of tumor necrosis factor inhibitors in the symptomatic treatment of axial disease, though their efficacy for halting progression of structural damage is less clear. Newly developed disease activity measures for JSpA include the Juvenile Arthritis Disease Activity Score and the JSpA Disease Activity index. In comparison to other categories of juvenile arthritis, children with JSpA are less likely to attain and sustain inactive disease. Summary Further microbiome and genetic research may help elucidate JSpA pathogenesis. More randomized therapeutic trials are needed and the advent of new composite disease activity measurement tools will hopefully allow for the design of these greatly needed trials. PMID:26002028

  17. Modelling potential impacts of bottom trawl fisheries on soft sediment biogeochemistry in the North Sea†

    Directory of Open Access Journals (Sweden)

    Parker Ruth

    2001-12-01

    Full Text Available Bottom trawling causes physical disturbance to sediments particularly in shelf areas. The disturbance due to trawling is most significant in deeper areas with softer sediments where levels of natural disturbance due to wave and tidal action are low. In heavily fished areas, trawls may impact the same area of seabed more than four times per year. A single pass of a beam trawl, the heaviest gear routinely used in shelf sea fisheries, can kill 5–65% of the resident fauna and mix the top few cm of sediment. We expect that sediment community function, carbon mineralisation and biogeochemical fluxes will be strongly affected by trawling activity because the physical effects of trawling are equivalent to those of an extreme bioturbator, and yet, unlike bioturbating macrofauna, trawling does not directly contribute to community metabolism. We used an existing box-model of a generalised soft sediment system to examine the effects of trawling disturbance on carbon mineralisation and chemical concentrations. We contrasted the effects of a natural scenario, where bioturbation is a function of macrobenthos biomass, with an anthropogenic impact scenario where physical disturbance results from trawling rather than the action of bioturbating macrofauna. Simulation results suggest that the effects of low levels of trawling disturbance will be similar to those of natural bioturbators but that high levels of trawling disturbance prevent the modelled system from reaching equilibrium due to large carbon fluxes between oxic and anoxic carbon compartments. The presence of macrobenthos in the natural disturbance scenario allowed sediment chemical storage and fluxes to reach equilibrium. This is because the macrobenthos are important carbon consumers in the system whose presence reduces the magnitude of available carbon fluxes. In soft sediment systems, where the level physical disturbance due to waves and tides is low, model results suggest that intensive trawling

  18. Effects of multiple acute stressors on the predator avoidance ability and physiology of juvenile Chinook salmon

    Science.gov (United States)

    Mesa, Matthew G.

    1994-01-01

    Northern squaw fish Ptychocheilus oregonensis are the predominant predators of juvenile Pacific salmonids Oncorhynchus spp. in the Columbia River, and their predation rates are greatest just below dams. Because juvenile salmonids are commonly subjected to multiple stressors at dams in the course of their seaward migration, high predation rates below dams may be due in part to an increase in the vulnerability of stressed fish. I conducted laboratory experiments to examine the predator avoidance ability and physiological stress responses of juvenile chinook salmon O. tshawytscha subjected to treatments (stressors) designed to simulate routine hatchery practices (multiple handlings) or dam passage (multiple agitations). Both stressors resulted in lethargic behavior in the fish, and agitation also caused disorieniation and occasional injury. When equal numbers of stressed and unstressed fish were exposed to northern squawfish for up to 1 h, significantly more stressed fish were eaten, but this effect was not evident during longer exposures. The lack of differential predation in trials lasting up to 24 h can be explained by the rapid development of schooling behavior in the prey, but other possibilities exist, such as changing ratios of stressed and unstressed prey over time. Concentrations of plasma cortisol, glucose, and lactate in fish subjected to multiple stressors were similar and sometimes cumulative, returned to prestress levels within 6-24 h, and correlated poorly with predator avoidance ability. My results suggest that juvenile salmonids are capable of avoiding predators within 1 h after being subjected to multiple acute stressors even though physiological homeostasis may be altered for up to 24 h. Therefore, because juvenile salmonids typically reside in lailrace areas for only a short time after dam passage, measures aimed at reducing physical stress or protecting them as they migrate through dam tailraces may help alleviate the relatively intense predation

  19. Virulence of Renibacterium salmoninarum to salmonids

    Science.gov (United States)

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

    1997-01-01

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

  20. Trophic feasibility of reintroducing anadromous salmonids in three reservoirs on the north fork Lewis River, Washington: Prey supply and consumption demand of resident fishes

    Science.gov (United States)

    Sorel, Mark H.; Hansen, Adam G.; Connelly, Kristin A.; Beauchamp, David A.

    2016-01-01

    The reintroduction of anadromous salmonids in reservoirs is being proposed with increasing frequency, requiring baseline studies to evaluate feasibility and estimate the capacity of reservoir food webs to support reintroduced populations. Using three reservoirs on the north fork Lewis River as a case study, we demonstrate a method to determine juvenile salmonid smolt rearing capacities for lakes and reservoirs. To determine if the Lewis River reservoirs can support reintroduced populations of juvenile stream-type Chinook Salmon Oncorhynchus tshawytscha, we evaluated the monthly production of daphniaDaphnia spp. (the primary zooplankton consumed by resident salmonids in the system) and used bioenergetics to model the consumption demand of resident fishes in each reservoir. To estimate the surplus of Daphnia prey available for reintroduced salmonids, we assumed a maximum sustainable exploitation rate and accounted for the consumption demand of resident fishes. The number of smolts that could have been supported was estimated by dividing any surplus Daphnia production by the simulated consumption demand of an individual Chinook Salmon fry rearing in the reservoir to successful smolt size. In all three reservoirs, densities of Daphnia were highest in the epilimnion, but warm epilimnetic temperatures and the vertical distribution of planktivores suggested that access to abundant epilimnetic prey was limited. By comparing accessible prey supply and demand on a monthly basis, we were able to identify potential prey supply bottlenecks that could limit smolt production and growth. These results demonstrate that a bioenergetics approach can be a valuable method of examining constraints on lake and reservoir rearing capacity, such as thermal structure and temporal food supply. This method enables numerical estimation of rearing capacity, which is a useful metric for managers evaluating the feasibility of reintroducing Pacific salmon Oncorhynchus spp. in lentic systems.

  1. Depth preference in released juvenile turbot Psetta maxima

    DEFF Research Database (Denmark)

    Albertsen, Christoffer Moesgaard; Støttrup, Josianne; Nielsen, Anders

    2014-01-01

    Hatchery-reared juvenile turbot Psetta maxima were tagged with Passive Integrated Transponder (PIT) tags and released at three different depths in a sandy bay in Denmark. About 2–7% of the released fish were registered daily to monitor their distribution using a tag antenna mounted on a modified...... beam trawl, thus avoiding actually sampling the fish. The change in distribution of the three groups was adequately represented by a twodimensional movement model. Movement along the shorewas described by a Brownianmotion with group specific drift.Movement perpendicular to the shore linewas described...

  2. Salmonid redd dewatering: What do we know

    Energy Technology Data Exchange (ETDEWEB)

    Becker, C D; Neitzel, D A

    1983-11-01

    Dewatering of salmonid spawning areas causes abrupt changes in the intergravel environment that may lead to extensive losses of development phases while intergravel in redds. Information on tolerance to dewatering and the extent of physicochemical changes in the gravel during dewatering can be used to assess potential impacts and to design and implement effective mitigation methods. Studies with fall chinook salmon are summarized, and the comparisons are made with results from available literature. Potentially useful methods of mitigation are mentioned. We found that prehatch phases (cleavage eggs and embryos) can be dewatered for several successive days and survive, but posthatch phases (eleutheroembryos and alevins) usually die within 24 hours. Survival of prehatch phases during extended dewatering requires maintenance of favorable intergravel temperature and moisture levels. Elevated temperatures (up to 22/sup 0/C) can be tolerated for up to 8 hours without direct adverse effects, but freezing temperatures (/sup -/1.0/sup 0/C or below) are lethal. Dewatered gravels must remain sufficient moisture to provide near 100% humidity for egg and embryo survival. In field situations, physicochemical conditions that limit survival in dewatered gravels include residual flow, temperature, gravel size and composition, and dissolved oxygen. Biological variables such as alevin behavior and certain species characteristics also influence survival. 29 refs., 6 figs.

  3. Ultrastructural morphogenesis of salmonid alphavirus 1.

    Science.gov (United States)

    Herath, T K; Ferguson, H W; Thompson, K D; Adams, A; Richards, R H

    2012-11-01

    Studies on the ultrastructural morphogenesis of viruses give an insight into how the host cell mechanisms are utilized for new virion synthesis. A time course examining salmonid alphavirus 1 (SAV 1) assembly was performed by culturing the virus on Chinook salmon embryo cells (CHSE-214). Different stages of viral replication were observed under electron microscopy. Virus-like particles were observed inside membrane-bound vesicles as early as 1 h following contact of the virus with the cells. Membrane-dependent replication complexes were observed in the cytoplasm of the cells, with spherules found at the periphery of late endosome-like vacuoles. The use of intracellular membranes for RNA replication is similar to other positive-sense single-stranded RNA (+ssRNA) viruses. The number of Golgi apparatus and associated vacuoles characterized by 'fuzzy'-coated membranes was greater in virus-infected cells. The mature enveloped virions started to bud out from the cells at approximately 24 h post-infection. These observations suggest that the pathway used by SAV 1 for the generation of new virus particles in vitro is comparable to viral replication observed with mammalian alphaviruses but with some interesting differences.

  4. Understanding the influence of predation on introduced fishes on juvenile salmonids in the Columbia River Basin: Closing some knowledge gaps. Late summer and fall diet and condition of smallmouth bass, walleye, and channel catfish in the middle Columbia River, USA. Interim Report of Research 2011.

    Science.gov (United States)

    Rose, Brien P.; Hansen, Gabriel S.; Weaver,; Ayers,; Van Dyke, Erick S.; Mesa, Matthew G.

    2012-01-01

    American shad Alosa sapidissima in the middle Columbia River (MCR)—a high energy food available in the summer and fall—may be contributing to the increased growth and enhanced condition of nonnative piscivores. To test this hypothesis we quantified the late summer and autumn diets of smallmouth bass Micropterus dolomieu, walleye Sander vitreus, and channel catfish Ictalurus punctatus in the three lowermost reservoirs on the Columbia River (Bonneville [BON], The Dalles [TDA], and John Day [JDA]). The diet of smallmouth bass (SMB) was fairly similar among reservoirs, with crustaceans (52–82%) and fish (13–38%) being the dominant prey groups by percent mass. Cottidae were usually the dominant fish prey in the diet of SMB at all areas and the contribution of juvenile shad ranged from 0–8.2%. Fish (mostly Cyprinidae and Cottidae) were always the dominant prey item for walleye (WAL) at all areas and at all times, ranging from 70–100% of their diet by mass. Juvenile American shad composed from 10–27% (by mass) of the diet of walleye, depending on area and month. For channel catfish (CHC), the most common prey items consumed were crustaceans (20%–80% by mass) and unidentified items (30%–80%). Fish represented a relatively small component (< 4%) of their diet. We also evaluated the condition of SMB and WAL by determining relative weights (Wr) and hepatosomatic indices (HSI). Mean Wr for SMB greater than 300 mm ranged from 0.89 to 0.94 depending on area and month and showed a significant increase from August to September for fish in BON only. Overall, mean Wr of WAL was similar at all areas, ranging from 0.89–0.91, and increased significantly from September to mid-October and November for fish in TDA only. Overall, mean HSI of SMB ranged from 1.18 to 1.48, did not differ between fish in different reservoirs, and increased significantly from September to mid-October and November for fish from the lower JDA only. Mean HSI of WAL was significantly higher in

  5. Salmonid-egg floating boxes as bioindication for riverine water quality and stocking success.

    Science.gov (United States)

    Pander, J; Geist, J

    2010-06-01

    The salmonid-egg floating box provides an easy bioindication tool for an assessment of water quality, as demonstrated here for the reintroduction of Europe's largest salmonid species, the huchen Hucho hucho.

  6. Juvenile Justice in Milwaukee

    Science.gov (United States)

    Williams, Gary L.; Greer, Lanetta

    2010-01-01

    Historically, there have been several attempts made to address issues surrounding juvenile delinquency. The Wisconsin Legislature outlines the objectives of the juvenile justice system in the Juvenile Justice Code in s. 939.01, ?to promote a juvenile justice system capable of dealing with the problem of juvenile delinquency, a system which will…

  7. Research, Monitoring, and Evaluation of Avian Predation on Salmonid Smolts in the Lower and Mid-Columbia River, 2006 Final Season Summary.

    Energy Technology Data Exchange (ETDEWEB)

    Roby, Daniel D. [USGS - Oregon Cooperative Fish and Wildlife Research Unit, Oregon State University; Collis, Ken [Real Time Research, Inc.; Lyons, Donald E. [USGS - Oregon Cooperative Fish and Wildlife Research Unit, Oregon State University

    2009-06-18

    This study investigates predation by piscivorous waterbirds on juvenile salmonids (Oncorhynchus spp.) from throughout the Columbia River Basin. During 2006, study objectives in the Columbia River estuary, work funded by the Bonneville Power Administration, were to (1) monitor and evaluate previous management initiatives to reduce Caspian tern (Hydroprogne caspia) predation on juvenile salmonids (smolts); (2) measure the impact of double-crested cormorant (Phalacrocorax auritus) predation on smolt survival, and assess potential management options to reduce cormorant predation; and (3) monitor large colonies of other piscivorous waterbirds in the estuary (i.e., glaucous-winged/western gulls [Larus glaucescens/occidentalis]) to determine the potential impacts on smolt survival. Study objectives on the mid-Columbia River, work funded by the Walla Walla District of the U.S. Army Corps of Engineers, were to (1) measure the impact of predation by Caspian terns and double-crested cormorants on smolt survival; and (2) monitor large nesting colonies of other piscivorous waterbirds (i.e., California gulls [L. californicus], ring-billed gulls [L. delawarensis], American white pelicans [Pelecanus erythrorhynchos]) on the mid-Columbia River to determine the potential for significant impacts on smolt survival. Our efforts to evaluate system-wide losses of juvenile salmonids to avian predation indicated that Caspian terns and double-crested cormorants were responsible for the vast majority of smolt losses to avian predators in the Columbia Basin, with most losses occurring in the Columbia River estuary. In 2006, East Sand Island in the Columbia River estuary supported the largest known breeding colonies of Caspian terns and double-crested cormorants in the world. The Caspian tern colony on East Sand Island consisted of about 9,200 breeding pairs in 2006, up slightly (but not significantly so) from the estimate of colony size in 2005 (8,820 pairs). There has not been a

  8. Juvenile xanthogranuloma.

    Science.gov (United States)

    Singh, R; Ghazali, W

    1992-05-01

    Juvenile xanthogranuloma is a benign cutaneous growth presenting as papules or nodules. It is characterized by an intradermal collection of lipid-laden macrophages and varying degrees of fibroblastic proliferation. We have recently observed two patients with xanthogranulomas: one was found to have a papular type and the second patient had multiple nodular growths. We present these cases, which should be considered in the differential diagnosis of skin nodules.

  9. The impact of shrimp trawling and associated sediment resuspension in mud dominated, shallow estuaries

    Energy Technology Data Exchange (ETDEWEB)

    Dellapenna, Timothy M.; Allison, Mead A.; Gill, Gary A.; Lehman, Ronald D.; Warnken, Kent W.

    2006-07-18

    To address the relative importance of shrimp trawling on seabed resuspension and bottom characteristics in shallow estuaries, a series of disturbance and monitoring experiments were conducted at a bay bottom mud site (2.5 m depth) in Galveston Bay, Texas in July 1998 and May 1999. Based on pre- and post-trawl sediment profiles of 7Be; pore water dissolved oxygen and sulfide concentration; and bulk sediment properties, it was estimated that the trawl rig, including the net, trawl doors, and ‘‘tickler chain,’’ excavate the seabed to a maximum depth of approximately 1.5 cm, with most areas displaying considerably less disturbance. Water column profile data in the turbid plume left by the trawl in these underconsolidated muds (85e90% porosity; <0.25 kPa undrained shear strength) demonstrate that suspended sediment inventories of up to 85e90 mg/cm2 are produced immediately behind the trawl net; an order of magnitude higher than pre-trawl inventories and comparable to those observed during a 9e10 m/s wind event at the study site. Plume settling and dispersion caused suspended sediment inventories to return to pre-trawl values about 14 min after trawl passage in two separate experiments, indicating particles re-settle primarily as flocs before they can be widely dispersed by local currents. As a result of the passage of the trawl rig across the seabed, shear strength of the sediment surface showed no significant increase, suggesting that bed armoring is not taking place and the trawled areas will not show an increase in critical shear stress.

  10. Efficacy, fate, and potential effects on salmonids of mosquito larvicides in catch basins in Seattle, Washington

    Science.gov (United States)

    Sternberg, Morgan; Grue, Christian; Conquest, Loveday; Grassley, James; King, Kerensa

    2012-01-01

    We investigated the efficacy, fate, and potential for direct effects on salmonids of 4 common mosquito larvicides (Mosquito Dunks® and Bits® (AI: Bacillis thuringiensis var. israelensis, [Bti]), VectoLex® WSP (AI: Bacillus sphaericus [Bs], VectoLex CG [AI: Bs], and Altosid® Briquets [AI: s-methoprene]) in Seattle, WA, during 3 summers. During efficacy trials in 2006, all treatments resulted in a rapid reduction in number of mosquito pupae (Mosquito Dunks and Bits and VectoLex WSP) or emergence success (Altosid Briquets). VectoLex CG was chosen for city-wide application in 2007 and 2008. The average counts of pupae within round-top basins remained significantly below the control average for 11 wk in 2007, whereas efficacy in grated-top basins was short-lived. In 2008 the average counts of pupae within grated-top basins remained significantly below the control average for 10 wk. Altosid XR was also effective in reducing adult emergence within grated basins in 2008. In 2007 and 2008, frequent precipitation events made the evaluation of efficacy difficult due to reductions in pupae across control and treated basins. Four separate analyses of VectoLex products revealed that the product was a combination of Bs and Bti. Both Bs and Bti were detected in 3 urban creeks connected to treated basins in 2007 and 2008. Laboratory toxicity test results suggest that concentrations of Bs and Bti detected in each of the watersheds pose little direct hazard to juvenile salmonids.

  11. Sustaining salmonid populations: A caring understanding of naturalness of taxa

    Science.gov (United States)

    Nielsen, J.L.; Regier, H.A.

    2004-01-01

    Species of the family of Salmonidae occur naturally in Northern Hemisphere waters that remain clear and cool to cold in summer. For purposes of reproduction, salmonids generally behaviorally respond to the currents of streams and lakes in recently glaciated areas. For feeding and maturation, many larger species migrate into existing systems of large lakes, seas, and oceans. The subfamilies include Salmoninae, Coregoninae, and Thymallinae. In many locales and regions of the hemisphere, numerous species of these subfamilies evolved and self-organized into species flocks or taxocenes of bewildering complexity. For example, any individual species may play different or unique ecological roles in different taxocenes. The northern Pacific and Atlantic Ocean ecosystems, with their seas and tributaries, each contained a metacomplex of such taxocenes that, in their natural state some centuries ago, resembled each other but differed in many ways. Humans have valued all species of this family for subsistence, ceremonial, naturalist, gustatory, angling, and commercial reasons for centuries. Modern progressive humans (MPHs), whose industrial and commercial enterprises have gradually spread over this hemisphere in recent time, now affect aquatic ecosystems at all scales from local to global. These human effects mingle in complex ways that together induce uniquely natural salmonid taxocenes to disintegrate with the loss of species, including those groups least tolerant to human manipulations, but extending more recently to those taxa more adapted to anthropogenic change. As we leave the modern era, dominated by MPHs, will we find ways to live sustainably with salmonid taxocenes that still exhibit self-organizational integrity, or will only individual, isolated populations of salmonid species, derived from those most tolerant of MPHs, survive? To achieve future sustainability of salmonids, we suggest implementation of a search for intuitive knowledge based on faith in the wisdom of

  12. The effects of trawling on the benthic fauna of the Gulf of Nicoya, Costa Rica.

    Science.gov (United States)

    Rostad, T; Hansen, K L

    2001-12-01

    Four van Veen grab replicates where collected to sample macrofauna (organism retained on a 500 micron mesh sieve) at four stations in the Gulf of Nicoya, during October 24, 1997, January 16 and April 30, 1998. This information was used to search for any effects of trawling on the benthic fauna. Two stations where located in a trawled area, and two stations where in a protected area. Diversity (H') varied from 2.01 to 3.52 in the trawled area and from 2.13 to 2.78 in the protected area. Diversity was generally higher in the trawled area, and this was in contradiction to what we would have expected from other studies where the trend has been that trawling reduces diversity. Brittlestars and lancelets seemed to be the groups mostly harmed by the trawling, while amphipods where more abundant in trawled areas. The multivariate analyses did not reveal the patterns of faunal change as well as we hoped. This is surely because of our lack of more replicate samples. The multivariate analyses are easily confounded when few sites are analyzed. We have found differences in the type of fauna found in trawled and protected areas and, considering the differences in environmental variables in our stations and our lack of replication, this indicates that there are differences and a larger investigation is in order to reveal its magnitude.

  13. Stable isotopes reveal the effect of trawl fisheries on the diet of commercially exploited species

    DEFF Research Database (Denmark)

    Hinz, Hilmar; Moranta, Joan; Balestrini, Stephen

    2017-01-01

    Bottom trawling can change food availability for benthivorous demersal species by (i) changing benthic prey composition through physical seabed impacts and (ii) by removing overall benthic consumer biomass increasing the net availability of benthic prey for remaining individuals. Thus trawling ma...

  14. Distribution of Bottom Trawling Effort in the Yellow Sea and East China Sea

    Science.gov (United States)

    Zhang, Shengmao; Jin, Shaofei; Zhang, Heng; Fan, Wei; Tang, Fenghua; Yang, Shenglong

    2016-01-01

    Bottom trawling is one of the most efficient fishing activities, but serious and persistent ecological issues have been observed by fishers, scientists and fishery managers. Although China has applied the Beidou fishing vessel position monitoring system (VMS) to manage trawlers since 2006, little is known regarding the impacts of trawling on the sea bottom environments. In this study, continuous VMS data of the 1403 single-rig otter trawlers registered in the Xiangshan Port, 3.9% of the total trawlers in China, were used to map the trawling effort in 2013. We used the accumulated distance (AD), accumulated power distance (APD), and trawling intensity as indexes to express the trawling efforts in the Yellow Sea (YS) and East China Sea (ECS). Our results show that all three indexes had similar patterns in the YS and ECS, and indicated a higher fishing effort of fishing grounds that were near the port. On average, the seabed was trawled 0.73 times in 2013 over the entire fishing region, and 51.38% of the total fishing grounds were with no fishing activities. Because of VMS data from only a small proportion of Chinese trawlers was calculated fishing intensity, more VMS data is required to illustrate the overall trawling effort in China seas. Our results enable fishery managers to identify the distribution of bottom trawling activities in the YS and ECS, and hence to make effective fishery policy. PMID:27855215

  15. Trophic look at soft-bottom communities - Short-term effects of trawling cessation on benthos

    Science.gov (United States)

    Dannheim, Jennifer; Brey, Thomas; Schröder, Alexander; Mintenbeck, Katja; Knust, Rainer; Arntz, Wolf E.

    2014-01-01

    The trophic structure of the German Bight soft-bottom benthic community was evaluated for potential changes after cessation of bottom trawling. Species were collected with van-Veen grabs and beam trawls. Trophic position (i.e. nitrogen stable isotope ratios, δ15N) and energy flow (i.e. species metabolism approximated by body mass scaled abundance) of dominant species were compared in trawled areas and an area protected from fisheries for 14 months in order to detect trawling cessation effects by trophic characteristics. At the community level, energy flow was lower in the protected area, but we were unable to detect significant changes in trophic position. At the species level energy flow in the protected area was lower for predating/scavenging species but higher for interface feeders. Species trophic positions of small predators/scavengers were lower and of deposit feeders higher in the protected area. Major reasons for trophic changes after trawling cessation may be the absence of artificial and additional food sources from trawling likely to attract predators and scavengers, and the absence of physical sediment disturbance impacting settlement/survival of less mobile species and causing a gradual shift in food availability and quality. Our results provide evidence that species or community energy flow is a good indicator to detect trawling induced energy-flow alterations in the benthic system, and that in particular species trophic properties are suitable to capture subtle and short-term changes in the benthos following trawling cessation.

  16. 50 CFR 660.333 - Open access non-groundfish trawl fishery-management measures.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Open access non-groundfish trawl fishery... COAST STATES West Coast Groundfish-Open Access Fisheries § 660.333 Open access non-groundfish trawl... the open access trip limit table, Table 3 (South) of this subpart. Trip limits for groundfish...

  17. Habitat selection influences sex distribution, morphology, tissue biochemistry, and parasite load of juvenile coho salmon in the West Fork Smith River, Oregon

    Science.gov (United States)

    Given the strong influence of water temperature on salmonid physiology and behavior, in the summers of 2004 and 2005 we studied juvenile male and female coho salmon Oncorhynchus kisutch in two reaches of Oregon’s West Fork Smith River with different thermal profiles. Our goals we...

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

    Directory of Open Access Journals (Sweden)

    Brahmbhatt Sonal

    2008-11-01

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

  19. Localisation of nursery areas based on comparative analyses of the horizontal and vertical distribution patterns of juvenile Baltic cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Nielsen, J. Rasmus; Lundgren, Bo; Kristensen, Kasper

    2013-01-01

    Baltic cod are determined, and their nursery areas are localised according to the environmental factors affecting them. Comparative statistical analyses of biological, hydrographic and hydroacoustic data are carried out based on standard ICES demersal trawl surveys and special integrated trawl...... patterns related to the seabed topography, water layer depth, and the presence of hydrographic frontal zones (pycnoclines) as well as intraspecific patterns in relation to the presence of adult cod. The extent of the nursery areas also depends on the cod year class strength. Juvenile cod (≥3 cm...

  20. Selective haddock (Melanogrammus aeglefinus) trawling: Avoiding cod (Gadus morhua) bycatch

    DEFF Research Database (Denmark)

    Krag, Ludvig Ahm; Holst, René; Madsen, Niels;

    2010-01-01

    The critical condition of the North Sea cod stocks has resulted in restrictions on not only cod, but also haddock and other species that are caught together with cod. Thus full exploitation of the haddock stock is unachievable unless cod can be excluded from the haddock catch. We designed a selec...... dependent: smaller cod escaped the trawl in greater numbers than did larger individuals. Whiting, saithe. lemon sole, and plaice were included in the analysis. (C) 2009 Elsevier B.V. All rights reserved....

  1. Dermatomiositis juvenil

    OpenAIRE

    Goldaracena, Pablo; Pérez, Federico

    2008-01-01

    La dermatomiositis juvenil (DMJ) es una enfermedad multi sistémica de etiología desconocida, caracterizada por una vasculitis que ocasiona una inflamación no supurativa del músculo estriado y lesiones cutáneas distintivas. La cobertura de los criterios de Bohan y Peter establece el diagnóstico: exantema patognomónico junto a debilidad muscular proximal simétrica, elevación sérica de enzimas musculares, s...

  2. SmeltCam: underwater video codend for trawled nets with an application to the distribution of the imperiled delta smelt.

    Directory of Open Access Journals (Sweden)

    Frederick Feyrer

    Full Text Available Studying rare and sensitive species is a challenge in conservation biology. The problem is exemplified by the case of the imperiled delta smelt Hypomesus transpacificus, a small delicate fish species endemic to the San Francisco Estuary, California. Persistent record-low levels of abundance and relatively high sensitivity to handling stress pose considerable challenges to studying delta smelt in the wild. To attempt to overcome these and other challenges we have developed the SmeltCam, an underwater video camera codend for trawled nets. The SmeltCam functions as an open-ended codend that automatically collects information on the number and species of fishes that pass freely through a trawled net without handling. We applied the SmeltCam to study the fine-scale distribution of juvenile delta smelt in the water column in the upper San Francisco Estuary. We learned that during flood tides delta smelt were relatively abundant throughout the water column and that during ebb tides delta smelt were significantly less abundant and occurred only in the lower half and sides of the water column. The results suggest that delta smelt manipulate their position in the water column to facilitate retention in favorable habitats. With the application of the SmeltCam we increased the survival of individual delta smelt by 72% compared to using a traditional codend, where all of the fish would have likely died due to handling stress. The SmeltCam improves upon similar previously developed silhouette photography or video recording devices and demonstrates how new technology can be developed to address important questions in conservation biology as well as lessen the negative effects associated with traditional sampling methods on imperiled species.

  3. The 'W' prawn-trawl with emphasised drag-force transfer to its centre line to reduce overall system drag.

    Directory of Open Access Journals (Sweden)

    Cheslav Balash

    Full Text Available For prawn trawling systems, drag reduction is a high priority as the trawling process is energy intensive. Large benefits have occurred through the use of multiple-net rigs and thin twine in the netting. An additional positive effect of these successful twine-area reduction strategies is the reduced amount of otter board area required to spread the trawl systems, which leads to further drag reduction. The present work investigated the potential of redirecting the drag-strain within a prawn trawl away from the wings and the otter boards to the centre line of the trawl, where top and bottom tongues have been installed, with an aim to minimise the loading/size of the otter boards required to spread the trawl. In the system containing the new 'W' trawl, the drag redirected to the centre-line tongues is transferred forward through a connected sled and towing wires to the trawler. To establish the extent of drag redirection to the centre-line tongues and the relative drag benefits of the new trawl system, conventional and 'W' trawls of 3.65 m headline length were tested firstly over a range of spread ratios in the flume tank, and subsequently at optimum spread ratio in the field. The developed 'W' trawl effectively directed 64% of netting-drag off the wings and onto the centre tongues, which resulted in drag savings in the field of ∼20% for the associated 'W' trawl/otter-board/sled system compared to the traditional trawl/otter-board arrangement in a single trawl or twin rig configuration. Furthermore, based on previously published data, the new trawl when used in a twin rig system is expected to provide approximately 12% drag reduction compared to quad rig. The twin 'W' trawl system also has benefits over quad rig in that a reduced number of cod-end/By-catch Reduction Device units need to be installed and attended each tow.

  4. Predation on Pacific salmonid eggs and carcass's by subyearling Atlantic salmon in a tributary of Lake Ontario

    Science.gov (United States)

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

    2016-01-01

    A binational effort to reintroduce Atlantic salmon (Salmo salar) that were extirpated in the Lake Ontario ecosystem for over a century is currently being undertaken by the New York State Department of Environmental Conservation and the Ontario Ministry of Natural Resources. Reintroduction actions include the release of several life stages including fry, fall fingerlings, and yearling smolts. In this study we describe the diet of recently released fall fingerling Atlantic salmon in a tributary of the Salmon River, New York. A specific objective of the study was to determine if juvenile Atlantic salmon would utilize the high caloric food source provided by introduced Pacific salmonids (Oncorhynchus spp.) that includes eggs and carcass flesh. Salmon eggs and carcass flesh comprised 20.5% of the October to January diet in 2013–14 and 23.9% in 2014–15. The consumption of steelhead (O. mykiss) eggs was a major part of the diet in April in both 2014 (54.1%) and 2015 (33.2%). This study documented that recently released Atlantic salmon will consume the high caloric food material provided by Pacific salmonids and that the consumption of this material extends for several months.

  5. A dataset from bottom trawl survey around Taiwan.

    Science.gov (United States)

    Shao, Kwang-Tsao; Lin, Jack; Wu, Chung-Han; Yeh, Hsin-Ming; Cheng, Tun-Yuan

    2012-01-01

    Bottom trawl fishery is one of the most important coastal fisheries in Taiwan both in production and economic values. However, its annual production started to decline due to overfishing since the 1980s. Its bycatch problem also damages the fishery resource seriously. Thus, the government banned the bottom fishery within 3 nautical miles along the shoreline in 1989. To evaluate the effectiveness of this policy, a four year survey was conducted from 2000-2003, in the waters around Taiwan and Penghu (Pescadore) Islands, one region each year respectively. All fish specimens collected from trawling were brought back to lab for identification, individual number count and body weight measurement. These raw data have been integrated and established in Taiwan Fish Database (http://fishdb.sinica.edu.tw). They have also been published through TaiBIF (http://taibif.tw), FishBase and GBIF (website see below). This dataset contains 631 fish species and 3,529 records, making it the most complete demersal fish fauna and their temporal and spatial distributional data on the soft marine habitat in Taiwan.

  6. A dataset from bottom trawl survey around Taiwan

    Directory of Open Access Journals (Sweden)

    Kwang-tsao Shao

    2012-05-01

    Full Text Available Bottom trawl fishery is one of the most important coastal fisheries in Taiwan both in production and economic values. However, its annual production started to decline due to overfishing since the 1980s. Its bycatch problem also damages the fishery resource seriously. Thus, the government banned the bottom fishery within 3 nautical miles along the shoreline in 1989. To evaluate the effectiveness of this policy, a four year survey was conducted from 2000–2003, in the waters around Taiwan and Penghu (Pescadore Islands, one region each year respectively. All fish specimens collected from trawling were brought back to lab for identification, individual number count and body weight measurement. These raw data have been integrated and established in Taiwan Fish Database (http://fishdb.sinica.edu.tw. They have also been published through TaiBIF (http://taibif.tw, FishBase and GBIF (website see below. This dataset contains 631 fish species and 3,529 records, making it the most complete demersal fish fauna and their temporal and spatial distributional data on the soft marine habitat in Taiwan.

  7. Modeling potential river management conflicts between frogs and salmonids

    Science.gov (United States)

    Steven F. Railsback; Bret C. Harvey; Sarah J. Kupferberg; Margaret M. Lang; Scott McBain; Hart H. Welsh

    2016-01-01

    Management of regulated rivers for yellow-legged frogs (Rana boylii) and salmonids exemplifies potential conflicts among species adapted to different parts of the natural flow and temperature regimes. Yellow-legged frogs oviposit in rivers in spring and depend on declining flows and warming temperatures for egg and tadpole survival and growth,...

  8. Water Temperature, Invertebrate Drift, and the Scope for Growth for Juvenile Spring Chinook Salmon.

    Science.gov (United States)

    Lovtang, J. C.; Li, H. W.

    2005-05-01

    We present a bioenergetic assessment of habitat quality based on the concept of the scope for growth for juvenile Chinook salmon. Growth of juvenile salmonids during the freshwater phase of their life history depends on a balance between two main factors: energy intake and metabolic costs. The metabolic demands of temperature and the availability of food play integral roles in determining the scope for growth of juvenile salmonids in stream systems. We investigated differences in size of juvenile spring Chinook salmon in relation to water temperature and invertebrate drift density in six unique study reaches in the Metolius River Basin, a tributary of the Deschutes River in Central Oregon. This project was initiated to determine the relative quality and potential productivity of habitat in the Metolius Basin prior to the reintroduction of spring Chinook salmon, which were extirpated from the middle Deschutes basin in the early 1970's due to the construction of a hydroelectric dam. Variations in the growth of juvenile Chinook salmon can be described using a multiple regression model of water temperature and invertebrate drift density. We also discuss the relationships between our bioenergetic model, variations of the ideal free distribution model, and physiological growth models.

  9. Research, Monitoring, and Evaluation of Avian Predation on Salmonid Smolts in the Lower and Mid-Columbia River, 2008 Draft Season Summary.

    Energy Technology Data Exchange (ETDEWEB)

    Roby, Daniel D. [USGS - Oregon Cooperative Fish and Wildlife Research Unit, Department of Fisheries and Wildlife, Oregon State University; Collis, Ken [Real Time Research, Inc.; Lyons, Donald E. [USGS - Oregon Cooperative Fish and Wildlife Research Unit, Oregon State University

    2009-07-08

    This report describes investigations into predation by piscivorous colonial waterbirds on juvenile salmonids (Oncorhynchus spp.) from throughout the Columbia River basin during 2008. East Sand Island in the Columbia River estuary again supported the largest known breeding colony of Caspian terns (Hydroprogne caspia) in the world (approximately 10,700 breeding pairs) and the largest breeding colony of double-crested cormorants (Phalacrocorax auritus) in western North America (approximately 10,950 breeding pairs). The Caspian tern colony increased from 2007, but not significantly so, while the double-crested cormorant colony experienced a significant decline (20%) from 2007. Average cormorant nesting success in 2008, however, was down only slightly from 2007, suggesting that food supply during the 2008 nesting season was not the principal cause of the decline in cormorant colony size. Total consumption of juvenile salmonids by East Sand Island Caspian terns in 2008 was approximately 6.7 million smolts (95% c.i. = 5.8-7.5 million). Caspian terns nesting on East Sand Island continued to rely primarily on marine forage fishes as a food supply. Based on smolt PIT tag recoveries on the East Sand Island Caspian tern colony, predation rates were highest on steelhead in 2008; minimum predation rates on steelhead smolts detected passing Bonneville Dam averaged 8.3% for wild smolts and 10.7% for hatchery-raised smolts. In 2007, total smolt consumption by East Sand Island double-crested cormorants was about 9.2 million juvenile salmonids (95% c.i. = 4.4-14.0 million), similar to or greater than that of East Sand Island Caspian terns during that year (5.5 million juvenile salmonids; 95% c.i. = 4.8-6.2 million). The numbers of smolt PIT tags recovered on the cormorant colony in 2008 were roughly proportional to the relative availability of PIT-tagged salmonids released in the Basin, suggesting that cormorant predation on salmonid smolts in the estuary was less selective than tern

  10. Survival and Passage of Juvenile Chinook Salmon and Steelhead Passing through Bonneville Dam, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Ploskey, Gene R.; Weiland, Mark A.; Hughes, James S.; Woodley, Christa M.; Deng, Zhiqun; Carlson, Thomas J.; Kim, Jin A.; Royer, Ida M.; Batten, George W.; Cushing, Aaron W.; Carpenter, Scott M.; Etherington, D. J.; Faber, Derrek M.; Fischer, Eric S.; Fu, Tao; Hennen, Matthew J.; Mitchell, Tyler; Monter, Tyrell J.; Skalski, John R.; Townsend, Richard L.; Zimmerman, Shon A.

    2011-12-01

    Pacific Northwest National Laboratory (PNNL) and subcontractors conducted an acoustic-telemetry study of juvenile salmonid fish passage and survival at Bonneville Dam in 2010. The study was conducted to assess the readiness of the monitoring system for official compliance studies under 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 single-release model. This also was the last year of evaluation of effects of a behavioral guidance device installed in the Powerhouse 2 forebay. The study relied on releases of live Juvenile Salmon Acoustic Telemetry System tagged smolts in the Columbia River and used acoustic telemetry to evaluate the approach, passage, and survival of passing juvenile salmon. This study supports the U.S. Army Corps of Engineers continual effort to improve conditions for juvenile anadromous fish passing through Columbia River dams.

  11. Survival and Passage of Juvenile Chinook Salmon and Steelhead Passing Through Bonneville Dam, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Ploskey, Gene R.; Weiland, Mark A.; Hughes, James S.; Woodley, Christa M.; Deng, Zhiqun; Carlson, Thomas J.; Kim, Jin A.; Royer, Ida M.; Batten, George W.; Cushing, Aaron W.; Carpenter, Scott M.; Etherington, D. J.; Faber, Derrek M.; Fischer, Eric S.; Fu, Tao; Hennen, Matthew J.; Mitchell, T. D.; Monter, Tyrell J.; Skalski, J. R.; Townsend, Richard L.; Zimmerman, Shon A.

    2012-09-01

    Pacific Northwest National Laboratory (PNNL) and subcontractors conducted an acoustic-telemetry study of juvenile salmonid fish passage and survival at Bonneville Dam in 2010. The study was conducted to assess the readiness of the monitoring system for official compliance studies under 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 single-release model. This also was the last year of evaluation of effects of a behavioral guidance device installed in the Powerhouse 2 forebay. The study relied on releases of live Juvenile Salmon Acoustic Telemetry System tagged smolts in the Columbia River and used acoustic telemetry to evaluate the approach, passage, and survival of passing juvenile salmon. This study supports the U.S. Army Corps of Engineers continual effort to improve conditions for juvenile anadromous fish passing through Columbia River dams.

  12. Survival and Passage of Juvenile Chinook Salmon and Steelhead Passing through Bonneville Dam, 2011

    Energy Technology Data Exchange (ETDEWEB)

    Ploskey, Gene R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Batten, G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cushing, Aaron W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kim, Jin A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Gary E. [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); Seaburg, Adam [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); Hughes, James S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carlson, Thomas J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carpenter, Scott M. [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); Fischer, Eric S. [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); Hennen, Matthew J. [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); Zimmerman, Shon A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-02-15

    Pacific Northwest National Laboratory (PNNL) and subcontractors conducted an acoustic-telemetry study of juvenile salmonid fish passage and survival at Bonneville Dam in 2011. The study was conducted to assess the readiness of the monitoring system for official compliance studies under 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. The study relied on releases of live Juvenile Salmon Acoustic Telemetry System tagged smolts in the Columbia River and used acoustic telemetry to evaluate the approach, passage, and survival of passing juvenile salmon using a virtual release, paired reference release survival model. This study supports the U.S. Army Corps of Engineers’ continual effort to improve conditions for juvenile anadromous fish passing through Columbia River dams.

  13. The seascape of demersal fish nursery areas in the North Mediterranean Sea, a first step towards the implementation of spatial planning for trawl fisheries.

    Science.gov (United States)

    Colloca, Francesco; Garofalo, Germana; Bitetto, Isabella; Facchini, Maria Teresa; Grati, Fabio; Martiradonna, Angela; Mastrantonio, Gianluca; Nikolioudakis, Nikolaos; Ordinas, Francesc; Scarcella, Giuseppe; Tserpes, George; Tugores, M Pilar; Valavanis, Vasilis; Carlucci, Roberto; Fiorentino, Fabio; Follesa, Maria C; Iglesias, Magdalena; Knittweis, Leyla; Lefkaditou, Eugenia; Lembo, Giuseppe; Manfredi, Chiara; Massutí, Enric; Pace, Marie Louise; Papadopoulou, Nadia; Sartor, Paolo; Smith, Christopher J; Spedicato, Maria Teresa

    2015-01-01

    The identification of nursery grounds and other essential fish habitats of exploited stocks is a key requirement for the development of spatial conservation planning aimed at reducing the adverse impact of fishing on the exploited populations and ecosystems. The reduction in juvenile mortality is particularly relevant in the Mediterranean and is considered as one of the main prerequisites for the future sustainability of trawl fisheries. The distribution of nursery areas of 11 important commercial species of demersal fish and shellfish was analysed in the European Union Mediterranean waters using time series of bottom trawl survey data with the aim of identifying the most persistent recruitment areas. A high interspecific spatial overlap between nursery areas was mainly found along the shelf break of many different sectors of the Northern Mediterranean indicating a high potential for the implementation of conservation measures. Overlap of the nursery grounds with existing spatial fisheries management measures and trawl fisheries restricted areas was also investigated. Spatial analyses revealed considerable variation depending on species and associated habitat/depth preferences with increased protection seen in coastal nurseries and minimal protection seen for deeper nurseries (e.g. Parapenaeus longirostris 6%). This is partly attributed to existing environmental policy instruments (e.g. Habitats Directive and Mediterranean Regulation EC 1967/2006) aiming at minimising impacts on coastal priority habitats such as seagrass, coralligenous and maerl beds. The new knowledge on the distribution and persistence of demersal nurseries provided in this study can support the application of spatial conservation measures, such as the designation of no-take Marine Protected Areas in EU Mediterranean waters and their inclusion in a conservation network. The establishment of no-take zones will be consistent with the objectives of the Common Fisheries Policy applying the ecosystem

  14. The seascape of demersal fish nursery areas in the North Mediterranean Sea, a first step towards the implementation of spatial planning for trawl fisheries.

    Directory of Open Access Journals (Sweden)

    Francesco Colloca

    Full Text Available The identification of nursery grounds and other essential fish habitats of exploited stocks is a key requirement for the development of spatial conservation planning aimed at reducing the adverse impact of fishing on the exploited populations and ecosystems. The reduction in juvenile mortality is particularly relevant in the Mediterranean and is considered as one of the main prerequisites for the future sustainability of trawl fisheries. The distribution of nursery areas of 11 important commercial species of demersal fish and shellfish was analysed in the European Union Mediterranean waters using time series of bottom trawl survey data with the aim of identifying the most persistent recruitment areas. A high interspecific spatial overlap between nursery areas was mainly found along the shelf break of many different sectors of the Northern Mediterranean indicating a high potential for the implementation of conservation measures. Overlap of the nursery grounds with existing spatial fisheries management measures and trawl fisheries restricted areas was also investigated. Spatial analyses revealed considerable variation depending on species and associated habitat/depth preferences with increased protection seen in coastal nurseries and minimal protection seen for deeper nurseries (e.g. Parapenaeus longirostris 6%. This is partly attributed to existing environmental policy instruments (e.g. Habitats Directive and Mediterranean Regulation EC 1967/2006 aiming at minimising impacts on coastal priority habitats such as seagrass, coralligenous and maerl beds. The new knowledge on the distribution and persistence of demersal nurseries provided in this study can support the application of spatial conservation measures, such as the designation of no-take Marine Protected Areas in EU Mediterranean waters and their inclusion in a conservation network. The establishment of no-take zones will be consistent with the objectives of the Common Fisheries Policy

  15. What a drag: Quantifying the global impact of chronic bottom trawling on continental shelf sediment

    Science.gov (United States)

    Oberle, Ferdinand K. J.; Storlazzi, Curt D.; Hanebuth, Till J. J.

    2016-07-01

    Continental shelves worldwide are subject to intense bottom trawling that causes sediment to be resuspended. The widely used traditional concepts of modern sedimentary transport systems on the shelf rely only on estimates for naturally driven sediment resuspension such as through storm waves, bottom currents, and gravity-driven flows but they overlook a critical anthropogenic factor. The strong influence of bottom trawling on a source-to-sink sediment budget is explored on the NW Iberian shelf. Use of Automated Information System vessel tracking data provides for a high-resolution vessel track reconstruction and the accurate calculation of the spatial distribution of bottom trawling intensity and associated resuspended sediment load. The mean bottom trawling-induced resuspended sediment mass for the NW Iberian shelf is 13.50 Mt yr- 1, which leads to a six-fold increase in off-shelf sediment transport when compared to natural resuspension mechanisms. The source-to-sink budget analysis provides evidence that bottom trawling causes a rapid erosion of the fine sediment on human time scales. Combining global soft sediment distribution data of the shelves with worldwide bottom trawling intensity estimates we show that the bottom trawling-induced resuspended sediment mass amounts to approximately the same mass of all sediment entering the shelves through rivers. Spatial delineations between natural and anthropogenic sediment resuspension areas are presented to aid in marine management questions.

  16. What a drag: Quantifying the global impact of chronic bottom trawling on continental shelf sediment

    Science.gov (United States)

    Oberle, Ferdinand K.J.; Storlazzi, Curt; Hanebuth, Till J.J.

    2016-01-01

    Continental shelves worldwide are subject to intense bottom trawling that causes sediment to be resuspended. The widely used traditional concepts of modern sedimentary transport systems on the shelf rely only on estimates for naturally driven sediment resuspension such as through storm waves, bottom currents, and gravity-driven flows but they overlook a critical anthropogenic factor. The strong influence of bottom trawling on a source-to-sink sediment budget is explored on the NW Iberian shelf. Use of Automated Information System vessel tracking data provides for a high-resolution vessel track reconstruction and the accurate calculation of the spatial distribution of bottom trawling intensity and associated resuspended sediment load. The mean bottom trawling-induced resuspended sediment mass for the NW Iberian shelf is 13.50 Mt yr− 1, which leads to a six-fold increase in off-shelf sediment transport when compared to natural resuspension mechanisms. The source-to-sink budget analysis provides evidence that bottom trawling causes a rapid erosion of the fine sediment on human time scales. Combining global soft sediment distribution data of the shelves with worldwide bottom trawling intensity estimates we show that the bottom trawling-induced resuspended sediment mass amounts to approximately the same mass of all sediment entering the shelves through rivers. Spatial delineations between natural and anthropogenic sediment resuspension areas are presented to aid in marine management questions.

  17. Benthic microbial abundance and activities in an intensively trawled ecosystem (Thermaikos Gulf, Aegean Sea)

    Science.gov (United States)

    Polymenakou, Paraskevi N.; Pusceddu, Antonio; Tselepides, Anastasios; Polychronaki, Thalia; Giannakourou, Antonia; Fiordelmondo, Carla; Hatziyanni, Eleni; Danovaro, Roberto

    2005-12-01

    Abundance of benthic bacteria, heterotrophic nanoflagellates and ciliates, extracellular enzymatic activities, bacterial C production, C mineralisation and sediment community oxygen consumption rates were measured in the Thermaikos Gulf (Northeastern Mediterranean), before (September 2001), and during intense trawling activities (October 2001 and February 2002). The biochemical composition of sedimentary organic matter has revealed that bottom trawling had an effect on the trophic state of Thermaikos Gulf. Changes on the benthic microbial food web were also recorded, during the three sampling seasons. Even though trawling-induced sediment resuspension did not alter significantly the abundance of the microbial components, with the exception of the most impacted station, it determined changes regarding their relative importance. Thus, the ratios of bacterium to nanoflagellates and ciliate to nanoflagellates abundance increased in the trawled stations, causing a sudden increase in bacterial C production, in comparison to the non-trawled station. Four months later, the effects of trawling on the microbial food web were less evident, masked possibly by the drastic decrease in the water temperature. The results of the present work suggest that bottom trawling induces alteration of the sedimentological variables and can be considered as a factor affecting the function of the microbial food web in marine coastal ecosystems. These alterations cause faster mobilisation of organic C buried in the sediment and increase nutrient concentrations and availability in the system, thus inducing an effect that could lead to coastal eutrophication.

  18. Juvenile salmon usage of the Skeena River estuary.

    Science.gov (United States)

    Carr-Harris, Charmaine; Gottesfeld, Allen S; Moore, Jonathan W

    2015-01-01

    Migratory salmon transit estuary habitats on their way out to the ocean but this phase of their life cycle is more poorly understood than other phases. The estuaries of large river systems in particular may support many populations and several species of salmon that originate from throughout the upstream river. The Skeena River of British Columbia, Canada, is a large river system with high salmon population- and species-level diversity. The estuary of the Skeena River is under pressure from industrial development, with two gas liquefaction terminals and a potash loading facility in various stages of environmental review processes, providing motivation for understanding the usage of the estuary by juvenile salmon. We conducted a juvenile salmonid sampling program throughout the Skeena River estuary in 2007 and 2013 to investigate the spatial and temporal distribution of different species and populations of salmon. We captured six species of juvenile anadromous salmonids throughout the estuary in both years, and found that areas proposed for development support some of the highest abundances of some species of salmon. Specifically, the highest abundances of sockeye (both years), Chinook in 2007, and coho salmon in 2013 were captured in areas proposed for development. For example, juvenile sockeye salmon were 2-8 times more abundant in the proposed development areas. Genetic stock assignment demonstrated that the Chinook salmon and most of the sockeye salmon that were captured originated from throughout the Skeena watershed, while some sockeye salmon came from the Nass, Stikine, Southeast Alaska, and coastal systems on the northern and central coasts of British Columbia. These fish support extensive commercial, recreational, and First Nations fisheries throughout the Skeena River and beyond. Our results demonstrate that estuary habitats integrate species and population diversity of salmon, and that if proposed development negatively affects the salmon populations that

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

    Science.gov (United States)

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

    2013-01-01

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

  20. Juvenile groundfish habitat in Kachemak Bay, Alaska, during late summer

    Science.gov (United States)

    Abookire, Alisa A.; Piatt, J.F.; Norcross, Brenda L.

    2001-01-01

    We investigated the habitat of juvenile groundfishes in relation to depth, water temperature, and salinity in Kachemak Bay, Alaska. Stations ranging in depth from 10 to 70 m and with sand or mud-sand substrates were sampled with a small-meshed beam trawl in August-September of 1994 to 1999. A total of 8,201 fishes were captured, comprising at least 52 species. Most fishes (91%) had a total length 5% of the total catch) were flathead sole Hippoglossoides elassodon, slim sculpin Radulinus asprellus, Pacific halibut Hippoglossus stenolepis, and arrowtooth flounder Atheresthes stomias. Depth accounted for most of the spatial variability in juvenile groundfish abundance, and neither temperature nor salinity was correlated with fish abundance. Juvenile groundfishes concentrated in either shallow (less than or equal to 20 m) or deep (50-70 m) water, with co-occurrence of some species between 30-40 m. Shallow fishes were the rock soles, Pacific halibut, and great sculpin Myoxocephalus polyacanthocephalus. Deep species were flathead sole, slim sculpin, spinycheek starsnout Bathyagonus infraspinatus, rex sole Glyptocephalus zachirus, tadpole sculpin Psychrolutes paradoxus, and whitebarred prickleback Poroclinus rothrocki. This 6-year study provides baseline data on relative abundance and distribution of juvenile groundfishes in Kachemak Bay and may provide a useful tool for predicting the presence of species in similar habitats in other areas of Alaska.

  1. Species and size selectivity of two midwater trawls used in an acoustic survey of the Alaska Arctic

    Science.gov (United States)

    De Robertis, Alex; Taylor, Kevin; Williams, Kresimir; Wilson, Christopher D.

    2017-01-01

    Acoustic-trawl (AT) survey methods are widely used to estimate the abundance and distribution of pelagic organisms. This technique relies on estimates of size and species composition from trawl catches along with estimates of the acoustic properties of these animals to convert measurements of acoustic backscatter into animal abundance. However, trawls are selective samplers, and if the catch does not represent the size and species composition of the animals in the acoustic beam the resulting abundance estimates will be biased. We conducted an experiment to quantify trawl selectivity for species encountered during an AT survey of the Alaska Arctic. The pelagic assemblage in this environment was dominated by small young-of-the-year (age-0) fishes and jellyfish, which may be poorly retained in trawls. A large midwater trawl (Cantrawl) and a smaller midwater trawl (modified Marinovich) were used during the survey. The Marinovich was equipped with 8 small-mesh recapture nets which were used to estimate the probability that an individual that enters the trawl is retained. In addition, paired hauls were made with the Cantrawl and Marinovich to estimate the difference in selectivity between the two trawls. A statistical model was developed to combine the catches of the recapture nets and the paired hauls to estimate the length-dependent selectivity of the trawls for the most abundant species (e.g., age-0 fishes and jellyfish). The analysis indicated that there was substantial size and species selectivity: although the modified Marinovich generally had a higher catch per unit effort, many of the animals encountered in this environment were poorly retained by both trawls. The observed size and species selectivity of the trawls can be used to select appropriate nets for sampling pelagic fishes, and correct survey estimates for the biases introduced in the trawl capture process.

  2. AFSC/REFM: Digitized 2005 GOA Trawl Logbooks merged with Fish Ticket and Observer data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data include a full year of logbook forms for vessels 60-124 feet in length (the partial coverage fleet) that had participated in the trawl flatfish fishery of...

  3. SEAMAP Groundfish/Shrimp Trawl Red Snapper Analytical Dataset Provided to NRDA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Southeast Fisheries Science Center Mississippi Laboratories has conducted standardized groundfish trawl surveys in the Gulf of Mexico since 1987. Prior to 1987,...

  4. Shelikof Strait Acoustic-Trawl Survey of Walleye Pollock (DY1203, ME70)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Midwater Assessment and Conservation Engineering (MACE) program of the Alaska Fisheries Science Center (AFSC) conducted an acoustic-trawl (AT) stock assessment...

  5. Oceanographic data - Integrated acoustic and trawl survey of Pacific hake off the Pacific Coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Integrated acoustic and trawl surveys are used to assess the distribution, biomass, and biology of Pacific hake along the Pacific coasts of the United States and...

  6. Trawling disturbance effects on the trophic ecology of two co-generic Astropectinid species

    Directory of Open Access Journals (Sweden)

    M. C. MANGANO

    2015-11-01

    Full Text Available Physical disturbance by trawling can have both negative and positive effects on populations of scavenging benthic organisms. In the present study the impact of fishing activity on feeding behaviour of the two Astropectinids, Astropecten bispinosus and A. irregularis, was assessed based on stomach contents analysis. The study was carried out along trawled seabed highlighting the positive response of the two facultative scavengers to carrion generated by trawl disturbance. Furthermore, there was greater food specialization in areas that were more heavily exploited by trawling. This specialisation could be linked to the availability of certain prey that results from the passage of fishing gears across the seabed. Interestingly, differences between the two species analysed have been highlighted in term of population dynamic, feeding rate, diet composition and diet diversity, testifying their capacity to coexist in the same fishing grounds. Normal 0 false false false EL X-NONE X-NONE  

  7. 76 FR 74725 - Fisheries Off West Coast States; Pacific Coast Groundfish Fishery Management Plan; Trawl...

    Science.gov (United States)

    2011-12-01

    ... seasonally to slow bycatch in the whiting fishery. In addition to closed areas to protect habitat from trawl... it will strive to the best of its ability to conduct site inspections in a timely fashion, not...

  8. Acoustic data - Integrated acoustic and trawl survey of Pacific hake off the Pacific Coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Integrated acoustic and trawl surveys are used to assess the distribution, biomass, and biology of Pacific hake along the Pacific coasts of the United States and...

  9. AFSC/RACE/MACE: Results of 2012 Chukchi Sea Acoustic/Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — We conducted acoustic-trawl (AT) surveys of the Alaska northern Bering and Chukchi Seas during ice-free periods with a focus on Arctic cod (Boreogadus saida), a key...

  10. AFSC/RACE/MACE: Results of 2015 acoustic trawl survey Gulf of Alaska M1501

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Three trawl-resistant bottom- mounted moorings (TRBM) instrumented with newly developed autonomous battery powered 70 kHz split-beam echosounders were deployed in...

  11. AFSC/RACE/MACE: Results of 2014 acoustic trawl survey Bogoslof DY1402

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists from the Midwater Assessment and Conservation Engineering (MACE) Program of the Alaska Fisheries Science Center (AFSC) regularly conduct acoustic-trawl...

  12. Veel haring, maar vrijwel geen jonge kabeljauw: International Bottom Trawl Survey 2003

    NARCIS (Netherlands)

    Heessen, H.J.L.

    2003-01-01

    Onderzoeksvaartuigen hebben de jaarlijkse International Bottom Trawl Survey (IBTS) uitgevoerd om een indruk te krijgen van de jongste jaarklassen van jonge haring, sprot en rondvis. Overzicht van de bestanden van kabeljauw, schelvis, wijting en haring 1978-2002

  13. NWFSC Observer Trawl Data, off West Coast of US, 2002-2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Observer Trawl Data collected during 2002-2006 off West Coast of US. This data product originates from data collected by fishery observers in the West Coast...

  14. NEFSC 2008 Spring Bottom Trawl Survey - Site Specific Calibration (HB0803, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  15. Fish diversity in southern California using trawl data from the National Marine Fisheries Service

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Shannon Index of diversity was calculated from National Marine Fisheries Service Groundfish Survey Program (NMFS GSP) fish trawl data. Data from 477 fishery...

  16. Biological data - Integrated acoustic and trawl survey of Pacific hake off the Pacific Coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Integrated acoustic and trawl surveys are used to assess the distribution, biomass, and biology of Pacific hake along the Pacific coasts of the United States and...

  17. Measurements of gear and environmental parameters during surveys with the GOV trawl

    National Research Council Canada - National Science Library

    Stewart, P.A.M; Rivoirard, J

    1997-01-01

    .... To investigate the catching performance of the GOV trawl, data were collected on 11 surveys. It was thought that catch would depend mainly on fishing ground, depth, year, swept volume, towing speed, water temperature and light intensity...

  18. Shumagin Islands Acoustic-Trawl Survey of Walleye Pollock (DY1201, ME70)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Midwater Assessment and Conservation Engineering (MACE) program of the Alaska Fisheries Science Center (AFSC) conducted an acoustic-trawl (AT) stock assessment...

  19. AFSC/RACE/MACE: Results of 2015 acoustic trawl survey Shumagin/Sanak/PWS DY1502

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The surveys primary objective was to collect acoustic data and trawl information to estimate midwater abundance and distribution of walleye pollock (Gadus...

  20. Tagging, Mux, smolt, habitat and flow data - Movement and Survival of Juvenile Salmonids in Small Streams

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project is part of the Washington State Intensively Monitored Watershed (IMW) Program. Using passive inductive transponder (PIT) tags and remote stationary...

  1. Acoustic Telemetry Evaluation of Juvenile Salmonid Passage and Survival Proportions at John Day Dam, 2009

    Energy Technology Data Exchange (ETDEWEB)

    Weiland, Mark A.; Ploskey, Gene R.; Hughes, James S.; Deng, Zhiqun; Fu, Tao; Kim, Jin A.; Johnson, Gary E.; Fischer, Eric S.; Khan, Fenton; Zimmerman, Shon A.; Faber, Derrek M.; Carter, Kathleen M.; Boyd, James W.; Townsend, Richard L.; Skalski, J. R.; Monter, Tyrell J.; Cushing, Aaron W.; Wilberding, Matthew C.; Meyer, Matthew M.

    2011-09-28

    The overall purpose of the acoustic telemetry study at JDA during 2009 was to determine the best configuration and operation for JDA prior to conducting BiOp performance standard tests. The primary objective was to determine the best operation between 30% and 40% spill treatments. Route-specific and JDA to TDA forebay survival estimates, passage distribution, and timing/behavior metrics were used for comparison of 30% to a 40% spill treatments. A secondary objective was to evaluate the performance of TSWs installed in spill bays 15 and 16 and to estimate fish survival rates and passage efficiencies under 30% and 40% spill-discharge treatments each season.

  2. Evaluation of Fish Passage Conditions for Juvenile Salmonids Using Sensor Fish at Detroit Dam, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, Joanne P.

    2010-01-29

    Fish passage conditions through two spillways at Detroit Dam on the North Santiam River in Oregon were evaluated by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers (USACE), Portland District, using Sensor Fish devices. The objective of the study was to describe and compare passage exposure conditions through Spillbay 3 and Spillbay 6 at 1.5- and 3.5-ft gate openings, identifying potential fish injury regions of the routes. The study was performed in July 2009, concurrent with HI-Z balloon-tag studies by Normandeau Associates, Inc. Sensor Fish and live fish were deployed at elevations approximately 3 ft above structure at depths determined using a computational fluid dynamics model. Data collected were analyzed to estimate 1) exposure conditions, particularly exposure to severe collision and shear events by passage route sub-regions; 2) differences in passage conditions between passage routes; and 3) relationships to live-fish injury and mortality data estimates.

  3. Vulnerability of individual fish to capture by trawling is influenced by capacity for anaerobic metabolism.

    Science.gov (United States)

    Killen, Shaun S; Nati, Julie J H; Suski, Cory D

    2015-08-22

    The harvest of animals by humans may constitute one of the strongest evolutionary forces affecting wild populations. Vulnerability to harvest varies among individuals within species according to behavioural phenotypes, but we lack fundamental information regarding the physiological mechanisms underlying harvest-induced selection. It is unknown, for example, what physiological traits make some individual fish more susceptible to capture by commercial fisheries. Active fishing methods such as trawling pursue fish during harvest attempts, causing fish to use both aerobic steady-state swimming and anaerobic burst-type swimming to evade capture. Using simulated trawling procedures with schools of wild minnows Phoxinus phoxinus, we investigate two key questions to the study of fisheries-induced evolution that have been impossible to address using large-scale trawls: (i) are some individuals within a fish shoal consistently more susceptible to capture by trawling than others?; and (ii) if so, is this related to individual differences in swimming performance and metabolism? Results provide the first evidence of repeatable variation in susceptibility to trawling that is strongly related to anaerobic capacity and swimming ability. Maximum aerobic swim speed was also negatively correlated with vulnerability to trawling. Standard metabolic rate was highest among fish that were least vulnerable to trawling, but this relationship probably arose through correlations with anaerobic capacity. These results indicate that vulnerability to trawling is linked to anaerobic swimming performance and metabolic demand, drawing parallels with factors influencing susceptibility to natural predators. Selection on these traits by fisheries could induce shifts in the fundamental physiological makeup and function of descendent populations.

  4. Columbia River System Operation Review : Final Environmental Impact Statement, Appendix C: Anadromous Fish and Juvenile Fish Transportation.

    Energy Technology Data Exchange (ETDEWEB)

    Columbia River System Operation Review (U.S.)

    1995-11-01

    This Appendix C of the Final Environmental Impact Statement for the Columbia River System discusses impacts on andromous fish and juvenile fish transportation. The principal andromous fish in the Columbia basin include salmonid species (Chinook, coho, and sockeye salmon, and steelhead) and nonsalmoinid andromous species (sturgeon, lamprey, and shad). Major sections in this document include the following: background, scope and process; affected environment for salmon and steelhead, shaded, lamprey, sturgeon; study methods; description of alternatives: qualitative and quantitative findings.

  5. Integrating the provision of ecosystem services and trawl fisheries for the management of the marine environment.

    Science.gov (United States)

    Muntadas, Alba; de Juan, Silvia; Demestre, Montserrat

    2015-02-15

    The species interaction and their biological traits (BT) determine the function of benthic communities and, hence, the delivery of ecosystem services. Therefore, disturbance of benthic communities by trawling may compromise ecosystem service delivery, including fisheries' catches. In this work, we explore 1) the impact of trawling activities on benthic functional components (after the BTA approach) and 2) how trawling impact may affect the ecosystem services delivered by benthic communities. To this aim, we assessed the provision of ecosystem services by adopting the concept of Ecosystem Service Providers (ESP), i.e. ecological units that perform ecosystem functions that will ultimately deliver ecosystem services. We studied thirteen sites subjected to different levels of fishing effort in the Mediterranean. From a range of environmental variables included in the study, we found ESPs to be mainly affected by fishing effort and grain size. Our results suggested that habitat type has significant effects on the distribution of ESPs and this natural variability influences ESP response to trawling at a specific site. In order to summarize the complex relationships between human uses, ecosystem components and the demand for ecosystem services in trawling grounds, we adapted a DPSIR (Drivers-Pressures-State Change-Impact-Response) framework to the study area, emphasizing the role of society as Drivers of change and actors demanding management Responses. This integrative framework aims to inform managers about the interactions between all the elements involved in the management of trawling grounds, highlighting the need for an integrated approach in order to ensure ecosystem service provision.

  6. Innate immune responses of salmonid fish to viral infections.

    Science.gov (United States)

    Collet, Bertrand

    2014-04-01

    Viruses are the most serious pathogenic threat to the production of the main aquacultured salmonid species the rainbow trout Oncorhynchus mykiss and the Atlantic salmon Salmo salar. The viral diseases Infectious Pancreatic Necrosis (IPN), Pancreatic Disease (PD), Infectious Haemorrhagic Necrosis (IHN), Viral Haemorrhagic Septicaemia (VHS), and Infectious Salmon Anaemia (ISA) cause massive economic losses to the global salmonid aquaculture industry every year. To date, no solution exists to treat livestock affected by a viral disease and only a small number of efficient vaccines are available to prevent infection. As a consequence, understanding the host immune response against viruses in these fish species is critical to develop prophylactic and preventive control measures. The innate immune response represents an important part of the host defence mechanism preventing viral replication after infection. It is a fast acting response designed to inhibit virus propagation immediately within the host, allowing for the adaptive specific immunity to develop. It has cellular and humoral components which act in synergy. This review will cover inflammation responses, the cell types involved, apoptosis, antimicrobial peptides. Particular attention will be given to the type I interferon system as the major player in the innate antiviral defence mechanism of salmonids. Viral evasion strategies will also be discussed.

  7. Sublethal toxicity of chlorpyrifos to salmonid olfaction after hypersaline acclimation.

    Science.gov (United States)

    Maryoung, Lindley A; Blunt, Brian; Tierney, Keith B; Schlenk, Daniel

    2015-04-01

    Salmonid habitats can be impacted by several environmental factors, such as salinization, which can also affect salmonid tolerance to anthropogenic stressors, such as pesticides. Previous studies have shown that hypersaline acclimation enhances the acute toxicity of certain organophosphate and carbamate pesticides to euryhaline fish; however, sublethal impacts have been far less studied. The current study aims to determine how hypersaline acclimation and exposure to the organophosphate chlorpyrifos (CPF) impact salmonid olfaction. Combined acclimation and exposure to CPF was shown to impact rainbow trout olfaction at the molecular, physiological, and behavioral levels. Concurrent exposure to hypersalinity and 0.5μg/L CPF upregulated four genes (chloride intracellular channel 4, G protein zgc:101761, calcium calmodulin dependent protein kinase II delta, and adrenergic alpha 2C receptor) that inhibit olfactory signal transduction. At the physiological level, hypersalinity and chlorpyrifos caused a decrease in sensory response to the amino acid l-serine and the bile salt taurocholic acid. Combined acclimation and exposure also negatively impacted behavior and reduced the avoidance of a predator cue (l-serine). Thus, acclimation to hypersaline conditions and exposure to environmentally relevant concentrations of chlorpyrifos caused an inhibition of olfactory signal transduction leading to a decreased response to odorants and impairment of olfactory mediated behaviors.

  8. What Is Juvenile Arthritis?

    Science.gov (United States)

    ... Analgesics for Osteoarthritis (Report from AHRQ) Joint Replacement Surgery: Health Information Basics for You and Your Family NIH Pediatric Rheumatology Clinic Health Information Juvenile Arthritis Find a Clinical Trial Journal Articles Juvenile Arthritis PDF Version Size: 123 KB ...

  9. Juvenile Delinquency: An Introduction

    Science.gov (United States)

    Smith, Carolyn A.

    2008-01-01

    Juvenile Delinquency is a term which is often inaccurately used. This article clarifies definitions, looks at prevalence, and explores the relationship between juvenile delinquency and mental health. Throughout, differences between males and females are explored. (Contains 1 table.)

  10. Parenting and juvenile delinquency

    NARCIS (Netherlands)

    Hoeve, Machteld

    2008-01-01

    Juvenile delinquency is a noteworthy problem. This thesis addressed the association between parenting and juvenile delinquency by analyzing the concepts of parenting adopted in family research in relation to criminological concepts and measures of delinquent behavior. Four studies were conducted.

  11. Assessment of Salmonids and Their Habitat Conditions in the Walla Walla River Basin within Washington, Annual Report 2002-2003.

    Energy Technology Data Exchange (ETDEWEB)

    Mendel, Glen; Trump, Jeremy; Gembala, Mike

    2003-09-01

    This study began in 1998 to assess salmonid distribution, relative abundance, genetics, and the condition of salmonid habitats in the Walla Walla River basin. Stream flows in the Walla Walla Basin continue to show a general trend that begins with a sharp decline in discharge in late June, followed by low summer flows and then an increase in discharge in fall and winter. Manual stream flow measurements at Pepper bridge showed an increase in 2002 of 110-185% from July-September, over flows from 2001. This increase is apparently associated with a 2000 settlement agreement between the U.S. Fish and Wildlife Service (USFWS) and the irrigation districts to leave minimum flows in the river. Stream temperatures in the Walla Walla basin were similar to those in 2001. Upper montane tributaries maintained maximum summer temperatures below 65 F, while sites in mid and lower Touchet and Walla Walla rivers frequently had daily maximum temperatures well above 68 F (high enough to inhibit migration in adult and juvenile salmonids, and to sharply reduce survival of their embryos and fry). These high temperatures are possibly the most critical physiological barrier to salmonids in the Walla Walla basin, but other factors (available water, turbidity or sediment deposition, cover, lack of pools, etc.) also play a part in salmonid survival, migration, and breeding success. The increased flows in the Walla Walla, due to the 2000 settlement agreement, have not shown consistent improvements to stream temperatures. Rainbow/steelhead (Oncorhynchus mykiss) trout represent the most common salmonid in the basin. Densities of Rainbow/steelhead in the Walla Walla River from the Washington/Oregon stateline to Mojonnier Rd. dropped slightly from 2001, but are still considerably higher than before the 2000 settlement agreement. Other salmonids including; bull trout (Salvelinus confluentus), chinook salmon (Oncorhynchus tshawytscha), mountain whitefish (Prosopium williamsoni), and brown trout (Salmo

  12. Juvenile Arrests, 2007. Juvenile Justice Bulletin

    Science.gov (United States)

    Puzzanchera, Charles

    2009-01-01

    This Bulletin summarizes 2007 juvenile crime and arrest data reported by local law enforcement agencies across the country and cited in the FBI report, "Crime in the United States 2007." The Bulletin describes the extent and nature of juvenile crime that comes to the attention of the justice system. It serves as a baseline for comparison for…

  13. Juvenile polyposis syndrome

    NARCIS (Netherlands)

    L.A.A. Brosens; D. Langeveld; W.A. van Hattem; F.M. Giardiello; G.J.A. Offerhaus

    2011-01-01

    Juvenile polyposis syndrome is a rare autosomal dominant syndrome characterized by multiple distinct juvenile polyps in the gastrointestinal tract and an increased risk of colorectal cancer. The cumulative life-time risk of colorectal cancer is 39% and the relative risk is 34. Juvenile polyps have a

  14. Evaluation of Juvenile Fish Bypass and Adult Fish Passage Facilities at Water Diversions in the Umatilla River; 1993 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, Suzanne M.

    1994-03-01

    This report presents progress from October 1992 through September 1993 in evaluating juvenile fish bypass facilities at Three Mile Falls, Maxwell, Westland, and Feed Canal dams on the Umatilla River, and in evaluating adult fish passage in the lower Umatilla River. Also reported is an effort to evaluate delayed mortality and stress responses of juvenile salmonids resulting from trapping and transport at high temperatures. These studies are part of a program to rehabilitate anadromous fish stocks in the matilla River Basin, including restoration of coho salmon and chinook salmon, as well as enhancement of summer steelhead.

  15. Patterns of dolphin bycatch in a north-western Australian trawl fishery.

    Science.gov (United States)

    Allen, Simon J; Tyne, Julian A; Kobryn, Halina T; Bejder, Lars; Pollock, Kenneth H; Loneragan, Neil R

    2014-01-01

    The bycatch of small cetaceans in commercial fisheries is a global wildlife management problem. We used data from skippers' logbooks and independent observers to assess common bottlenose dolphin (Tursiops truncatus) bycatch patterns between 2003 and 2009 in the Pilbara Trawl Fishery, Western Australia. Both datasets indicated that dolphins were caught in all fishery areas, across all depths and throughout the year. Over the entire datasets, observer reported bycatch rates (n = 52 dolphins in 4,124 trawls, or 12.6 dolphins/1,000 trawls) were ca. double those reported by skippers (n = 180 dolphins in 27,904 trawls, or 6.5 dolphins/1,000 trawls). Generalised Linear Models based on observer data, which better explained the variation in dolphin bycatch, indicated that the most significant predictors of dolphin catch were: (1) vessel--one trawl vessel caught significantly more dolphins than three others assessed; (2) time of day--the lowest dolphin bycatch rates were between 00:00 and 05:59; and (3) whether nets included bycatch reduction devices (BRDs)--the rate was reduced by ca. 45%, from 18.8 to 10.3 dolphins/1,000 trawls, after their introduction. These results indicated that differences among vessels (or skippers' trawling techniques) and dolphin behavior (a diurnal pattern) influenced the rates of dolphin capture; and that spatial or seasonal adjustments to trawling effort would be unlikely to significantly reduce dolphin bycatch. Recent skipper's logbook data show that dolphin bycatch rates have not declined since those reported in 2006, when BRDs were introduced across the fishery. Modified BRDs, with top-opening escape hatches from which dolphins might escape to the surface, may be a more effective means of further reducing dolphin bycatch. The vulnerability of this dolphin population to trawling-related mortality cannot be assessed in the absence of an ongoing observer program and without information on trawler-associated dolphin community size

  16. Influence of fleet renewal and trawl development on landings per unit effort of the Danish northern shrimp (Pandalus borealis) fishery

    DEFF Research Database (Denmark)

    Eigaard, Ole Ritzau; Munch-Petersen, Sten

    2011-01-01

    , the relationship between nominal effort data as recorded in logbooks (days fishing) and effective effort is likely to have changed, so to standardize the nominal lpue time-series, trawl-size development has been taken into account using generalized linear modelling. As logbooks do not provide trawl......-size information, this standardization was made possible by retrieving technical trawl and vessel data from industry order books. These data demonstrated an approximately linear relationship between vessel engine power and Pandalus trawl size, so validated the use of vessel horsepower from the logbooks as a proxy...

  17. Occurrence and significance of atypical Aeromonas salmonicida in non-salmonid and salmonid fish species: a review.

    Science.gov (United States)

    Wiklund, T; Dalsgaard, I

    1998-02-26

    Bacterial strains of Aeromonas salmonicida included in the recognized subsp. acromogenes, subsp. masoucida, and subsp. smithia in addition to the large number of strains not included in any of the described subspecies are referred to as atypical A. salmonicida. The atypical strains form a very heterogeneous group with respect to biochemical characteristics, growth conditions, and production of extracellular proteasess. Consequently, the present taxonomy of the species A. salmonicida is rather ambiguous. Atypical A. salmonicida has been isolated from a wide range of cultivated and wild fish species, non-salmonids as well as salmonids, inhabiting fresh water, brackish water and marine environments in northern and central Europe, South Africa, North America, Japan and Australia. In non-salmonid fish species, infections with atypical strains often manifest themselves as superficial skin ulcerations. The best known diseases associated with atypical A. salmonicida are carp Cyprinus carpio erythrodermatitis, goldfish Carassius auratus ulcer disease, and ulcer disease of flounder Platichthys flesus, but atypical strains are apparently involved in more disease outbreaks than previously suspected. Macroscopical and microscopical studies of ulcerated fish indicate internal organs are infrequently invaded by atypical A. salmonicida. This view is supported by the fact that atypical strains are irregularly isolated from visceral organs of ulcerated fish. High mortality caused by atypical A. salmonicida has been observed in populations of wild non-salmonids and farmed salmonids, although the association between the mortality in the wild fish stocks and atypical A. salmonicida has not always been properly assessed. In injection experiments the pathogenicity of the atypical strains examined showed large variation. An extacellular A-layer has been detected in different atypical strains, but virulence mechanisms different from those described for (typical) A. salmonicida subsp

  18. Diversity of Flavobacterium psychrophilum and the potential use of its phages for protection against bacterial cold water disease in salmonids

    DEFF Research Database (Denmark)

    Castillo, D.; Higuera, G.; Villa, M.

    2012-01-01

    Flavobacterium psychrophilum causes rainbow trout fry syndrome (RTFS) and cold water disease (CWD) in salmonid aquaculture. We report characterization of F. psychrophilum strains and their bacteriophages isolated in Chilean salmonid aquaculture. Results suggest that under laboratory conditions ph...

  19. Vertebrae classification models - Validating classification models that use morphometrics to identify ancient salmonid (Oncorhynchus spp.) vertebrae to species

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Using morphometric characteristics of modern salmonid (Oncorhynchus spp.) vertebrae, we have developed classification models to identify salmonid vertebrae to the...

  20. Juveniles on trial.

    Science.gov (United States)

    Quinn, Kathleen M

    2002-10-01

    This article describes common forensic evaluations requested of juvenile court mental health evaluators. There has been a legal shift toward criminalization of juvenile court, with a greater emphasis on rights, abandonment of the rehabilitative model, and greater movement of adolescents into the adult criminal court. A resulting shift has been the redefinition of juvenile court forensic evaluations toward the specificity of adult forensic work. The challenge for evaluators is to refine their knowledge of the forensic standards and bring knowledge of development, assessment, and diagnosis in juveniles and interview techniques appropriate to juveniles to improve the evaluation and forensic reports.

  1. 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.

  2. Juvenile polyposis syndrome

    Institute of Scientific and Technical Information of China (English)

    Lodewijk AA Brosens; Danielle Langeveld; W Arnout van Hattem; Francis M Giardiello; G Johan A Offerhaus

    2011-01-01

    Juvenile polyposis syndrome is a rare autosomal dominant syndrome characterized by multiple distinct juvenile polyps in the gastrointestinal tract and an increased risk of colorectal cancer.The cumulative life-time risk of colorectal cancer is 39% and the relative risk is 34.Juvenile polyps have a distinctive histology characterized by an abundance of edematous lamina propria with inflammatory cells and cystically dilated glands lined by cuboidal to columnar epithelium with reactive changes.Clinically, juvenile polyposis syndrome is defined by the presence of 5 or more juvenile polyps in the colorectum,juvenile polyps throughout the gastrointestinal tract or any number of juvenile polyps and a positive family history of juvenile polyposis.In about 50%-60% of patients diagnosed with juvenile polyposis syndrome a germline mutation in the SMAD4 or BMPR1A gene is found.Both genes play a role in the BMP/TGF-beta signalling pathway.It has been suggested that cancer in juvenile polyposis may develop through the so-alled "landscaper mechanism" where an abnormal stromal environment leads to neoplastic transformation of the adjacent epithelium and in the end invasive carcinoma.Recognition of this rare disorder is important for patients and their families with regard to treatment,follow-up and screening of at risk individuals.Each clinician confronted with the diagnosis of a juvenile polyp should therefore consider the possibility of juvenile polyposis syndrome.In addition, juvenile polyposis syndrome provides a unique model to study colorectal cancer pathogenesis in general and gives insight in the molecular genetic basis of cancer. This review discusses clinical manifestations, genetics, pathogenesis and management of juvenile polyposis syndrome.

  3. Assessment of Native Salmonids Above Hells Canyon Dam, Idaho; 1998 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Kevin A. (Idaho Department of Fish and Game, Boise, ID)

    1999-03-01

    Native resident salmonids in the western United States are in decline throughout much of their range. The purpose of the multi-phased project is to restore native salmonids in the upper Snake River basin to self-sustaining, harvestable levels.

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

    Science.gov (United States)

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

    2016-03-01

    Epizootic epitheliotropic disease virus (EEDV; salmonid herpesvirus [SalHV3]; family Alloherpesviridae) causes a systemic disease of juvenile and yearling Lake Trout Salvelinus namaycush. No cell lines are currently available for the culture and propagation of EEDV, so primary diagnosis is limited to PCR and electron microscopy. To better understand the pervasiveness of EEDV (carrier or latent state of infection) in domesticated and wild Lake Trout populations, we developed a sensitive TaqMan quantitative PCR (qPCR) assay to detect the presence of the EEDV terminase gene in Lake Trout tissues. This assay was able to detect a linear standard curve over nine logs of plasmid dilution and was sensitive enough to detect single-digit copies of EEDV. The efficiency of the PCR assay was 99.4 ± 0.06% (mean ± SD), with a 95% confidence limit of 0.0296 (R(2) = 0.994). Methods were successfully applied to collect preliminary data from a number of species and water bodies in the states of Pennsylvania, New York, and Vermont, indicating that EEDV is more common in wild fish than previously known. In addition, through the development of this qPCR assay, we detected EEDV in a new salmonid species, the Cisco Coregonus artedi. The qPCR assay was unexpectedly able to detect two additional herpesviruses, the Atlantic Salmon papillomatosis virus (ASPV; SalHV4) and the Namaycush herpesvirus (NamHV; SalHV5), which both share high sequence identity with the EEDV terminase gene. With these unexpected findings, we subsequently designed three primer sets to confirm initial TaqMan qPCR assay positives and to differentiate among EEDV, ASPV, and NamHV by detecting the glycoprotein genes via SYBR Green qPCR. Received April 20, 2015; accepted November 10, 2015.

  5. Research, Monitoring, and Evaluation of Avian Predation on Salmonid Smolts in the Lower and Mid-Columbia River, 2008 Draft Season Summary.

    Energy Technology Data Exchange (ETDEWEB)

    Roby, Daniel D. [USGS - Oregon Cooperative Fish and Wildlife Research Unit, Department of Fisheries and Wildlife, Oregon State University; Collis, Ken [Real Time Research, Inc.; Lyons, Donald E. [USGS - Oregon Cooperative Fish and Wildlife Research Unit, Oregon State University

    2009-07-08

    This report describes investigations into predation by piscivorous colonial waterbirds on juvenile salmonids (Oncorhynchus spp.) from throughout the Columbia River basin during 2008. East Sand Island in the Columbia River estuary again supported the largest known breeding colony of Caspian terns (Hydroprogne caspia) in the world (approximately 10,700 breeding pairs) and the largest breeding colony of double-crested cormorants (Phalacrocorax auritus) in western North America (approximately 10,950 breeding pairs). The Caspian tern colony increased from 2007, but not significantly so, while the double-crested cormorant colony experienced a significant decline (20%) from 2007. Average cormorant nesting success in 2008, however, was down only slightly from 2007, suggesting that food supply during the 2008 nesting season was not the principal cause of the decline in cormorant colony size. Total consumption of juvenile salmonids by East Sand Island Caspian terns in 2008 was approximately 6.7 million smolts (95% c.i. = 5.8-7.5 million). Caspian terns nesting on East Sand Island continued to rely primarily on marine forage fishes as a food supply. Based on smolt PIT tag recoveries on the East Sand Island Caspian tern colony, predation rates were highest on steelhead in 2008; minimum predation rates on steelhead smolts detected passing Bonneville Dam averaged 8.3% for wild smolts and 10.7% for hatchery-raised smolts. In 2007, total smolt consumption by East Sand Island double-crested cormorants was about 9.2 million juvenile salmonids (95% c.i. = 4.4-14.0 million), similar to or greater than that of East Sand Island Caspian terns during that year (5.5 million juvenile salmonids; 95% c.i. = 4.8-6.2 million). The numbers of smolt PIT tags recovered on the cormorant colony in 2008 were roughly proportional to the relative availability of PIT-tagged salmonids released in the Basin, suggesting that cormorant predation on salmonid smolts in the estuary was less selective than tern

  6. Commercial bottom trawling: a driver of deep seascape evolution in the Anthropocene?

    Science.gov (United States)

    Martín, Jacobo; Puig, Pere; Canals, Miquel; Company, Joan B.; Amblas, David; Lastras, Galderic; Palanques, Albert; Calafat, Antoni M.

    2013-04-01

    The offshore displacement of bottom trawling fleets has raised concerns over the impact of this human activity on deep-sea ecosystems and associated living resources, which are characterized by a lower resilience than shallow water correlatives. However, the effects of bottom trawling on sediment remobilization across continental margins and on the alteration of seafloor morphology still remain largely unaddressed. We present a compilation of results from studies conducted during the last decade in the La Fonera (Palamós) submarine canyon (NW Mediterranean Sea), where a bottom trawling fishing fleet is active on a daily basis at depths from 400 to 800 m. Deployments of mooring lines equipped with punctual and profiling current-meters, turbidimeters and sediment traps have documented that trawling gears passing along the canyon flanks generate daily sediment gravity flows, implying a periodic sediment removal from fishing grounds. These sediment-laden flows are able to reach the main canyon axis and progress to a minimum depth of 1200 m. Also, sediment accumulation rates in the lower canyon have increased since the industrialization of the local trawling fleet (1970s), suggesting a human-induced enhancement of along-canyon transfer of sediments from the fishing grounds to greater depths. Sedimentological and Pb-210 analysis of interface sediment cores collected from the canyon flanks confirm that widespread erosion and stirring of surface sediments is notable on trawled areas when compared to control (untrawled) sites at similar depths. This chronic reworking and removal of surface sediments from trawling grounds has ultimately led to modifications of the seafloor morphology over large spatial scales, as revealed by high-resolution multibeam bathymetry and Vessel Monitoring Systems (VMS) data sets. Untrawled canyon flank segments are dominated by a dense network of tributary valleys that progress upslope from the main canyon axis, reaching up to five orders of

  7. An epidemiological model for proliferative kidney disease in salmonid populations.

    Science.gov (United States)

    Carraro, Luca; Mari, Lorenzo; Hartikainen, Hanna; Strepparava, Nicole; Wahli, Thomas; Jokela, Jukka; Gatto, Marino; Rinaldo, Andrea; Bertuzzo, Enrico

    2016-09-05

    Proliferative kidney disease (PKD) affects salmonid populations in European and North-American rivers. It is caused by the endoparasitic myxozoan Tetracapsuloides bryosalmonae, which exploits freshwater bryozoans and salmonids as hosts. Incidence and severity of PKD in brown trout populations have recently increased rapidly, causing a decline in fish catches and local extinctions in many river systems. PKD incidence and fish mortality are known to be enhanced by warmer water temperatures. Therefore, environmental change is feared to increase the severity of PKD outbreaks and extend the disease range to higher latitude and altitude regions. We present the first mathematical model regarding the epidemiology of PKD, including the complex life-cycle of its causative agent across multiple hosts. A dynamical model of PKD epidemiology in riverine host populations is developed. The model accounts for local demographic and epidemiological dynamics of bryozoans and fish, explicitly incorporates the role of temperature, and couples intra-seasonal and inter-seasonal dynamics. The former are described in a continuous-time domain, the latter in a discrete-time domain. Stability and sensitivity analyses are performed to investigate the key processes controlling parasite invasion and persistence. Stability analysis shows that, for realistic parameter ranges, a disease-free system is highly invasible, which implies that the introduction of the parasite in a susceptible community is very likely to trigger a disease outbreak. Sensitivity analysis shows that, when the disease is endemic, the impact of PKD outbreaks is mostly controlled by the rates of disease development in the fish population. The developed mathematical model helps further our understanding of the modes of transmission of PKD in wild salmonid populations, and provides the basis for the design of interventions or mitigation strategies. It can also be used to project changes in disease severity and prevalence because

  8. Deep Sea Coral voucher sequence dataset - Identification of deep-sea corals collected during the 2009 - 2014 West Coast Groundfish Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data for this project resides in the West Coast Groundfish Bottom Trawl Survey Database. Deep-sea corals are often components of trawling bycatch, though their...

  9. AFSC/RACE/GAP/Palsson: Gulf of Alaska and Aleutian Islands Biennial Bottom Trawl Survey estimates of catch per unit effort, biomass, population at length, and associated tables

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The GOA/AI Bottom Trawl Estimate database contains abundance estimates for the Alaska Biennial Bottom Trawl Surveys conducted in the Gulf of Alaska and the Aleutian...

  10. Sea lice as a density-dependent constraint to salmonid farming.

    Science.gov (United States)

    Jansen, Peder A; Kristoffersen, Anja B; Viljugrein, Hildegunn; Jimenez, Daniel; Aldrin, Magne; Stien, Audun

    2012-06-22

    Fisheries catches worldwide have shown no increase over the last two decades, while aquaculture has been booming. To cover the demand for fish in the growing human population, continued high growth rates in aquaculture are needed. A potential constraint to such growth is infectious diseases, as disease transmission rates are expected to increase with increasing densities of farmed fish. Using an extensive dataset from all farms growing salmonids along the Norwegian coast, we document that densities of farmed salmonids surrounding individual farms have a strong effect on farm levels of parasitic sea lice and efforts to control sea lice infections. Furthermore, increased intervention efforts have been unsuccessful in controlling elevated infection levels in high salmonid density areas in 2009-2010. Our results emphasize host density effects of farmed salmonids on the population dynamics of sea lice and suggest that parasitic sea lice represent a potent negative feedback mechanism that may limit sustainable spatial densities of farmed salmonids.

  11. Deciphering the lithological consequences of bottom trawling to sedimentary habitats on the shelf

    Science.gov (United States)

    Oberle, Ferdinand K. J.; Swarzenski, Peter W.; Reddy, Christopher M.; Nelson, Robert K.; Baasch, Benjamin; Hanebuth, Till J. J.

    2016-07-01

    Widespread bottom trawling on the NW Iberian shelf causes chronic sediment and habitat disturbance. The few studies that have investigated vessel-modified sedimentary-structure and texture of the seabed have typically classified their results as being either impacted by trawling or not. This study indicates that bottom trawling can result in a sequence of vastly different effects to the lithology of seabed sediment, which have in turn different ecological consequences. Here, we combined very high-resolution spatial bottom-trawling data with sedimentological (grain size, porosity) and geochemical datasets (excess 210Pb, 3D petroleum fingerprinting) to study sediment disturbance, including sorting and mixing. Our results were used to develop five conceptual disturbance scenarios: minimal seabed effects, sediment overturning, complete sediment mixing, sediment grading and layering, and loss of sediment. Considering that bottom trawling is a widespread and growing global fishing technique, such impacts need to be considered in the management of habitat conservation as well as in the reconstruction of late Holocene climate history from shallow-water deposits, not just on the NW Iberian shelf, but also globally.

  12. ON THE ORIGIN OF THE BALKAN PENINSULA SALMONIDS

    Directory of Open Access Journals (Sweden)

    Simo Georgiev

    2003-12-01

    Full Text Available This paper puts forward the knowledge of the immigration itineraries of the ancestors of five extant salmonid species on Balkan Peninsula which are the following: Acantholingua ohridana (Steindachner, 1892, Hucho hucho (Linnaeus, 1758, Salmo trutta Linnaeus, 1758, Salmothymus obtusirostris Heckel, 1851 and Thymallus thymallus (Linnaeus, 1758. The thesis for the migration itineraries is based on the anatomical, molecular and zoogeographical facts recently published. These latest facts complement or reject the previous thesis that considered the origin of separate species, which in this paper are analyzed together. A new position on the origin of some S. trutta populations inhabiting the Mediterranean Sea watershed is proposed. The new thesis is that they did not inhabit it from the west, through the Atlantic Ocean and Gibraltar, but from the North, through the branches of the former Sarmatian Sea, using the continental way. A. ohridana and S. obtusirostris, the only endemic Balkanean salmonids, have developed here from the mutual ancestor with the extant Siberian Brachymystax lenok (Pallas, 1773. This ancestor came first, together with the S. trutta lineage known as »marmorata«. Using the same migration way, the T. thymallus population of Soča River, the North.West boundary of Balkan Peninsula remained restricted at that corner of Adriatic Sea watershed. In the Black Sea watershed (the Danube River flow extension on Balkan Peninsula the distribution of T. thymallus coincides with the distribution of H. hucho. The thesis which has been proposed for this, largest contemporary Balkan Peninsula salmonid fish was that it came here last, after the connections between the Mediterranean Sea basin and once existent Sarmatian Sea disappeared. This occurred after the end of the last glaciations. This has been concluded on the basis of the exclusion of the areas of the »marmorata« lineage of S. trutta (Mediterranean Sea watershed and H. hucho (Black Sea

  13. Effects of trawling on the diets of common demersal fish by-catch of a tropical prawn trawl fishery.

    Science.gov (United States)

    Dell, Q; Griffiths, S P; Tonks, M L; Rochester, W A; Miller, M J; Duggan, M A; van der Velde, T D; Pillans, R D; Coman, G J; Bustamante, R H; Milton, D A

    2013-03-01

    The ecological effect of prawn trawling on the benthos of the Gulf of Carpentaria, northern Australia, was investigated by examining stomach contents of common demersal fishes incidentally caught as by-catch in the fishery. Fishes were collected from high and low fishing intensity sites in three regions based on vessel monitoring system data. The diets of eight species of benthic fish predators were compared between regions and fishing intensities. A regional effect on diet was evident for seven species. Only one generalist species had no significant difference in diet among the three regions. For the comparisons within each region, five predator species had significantly different diet between high and low fishing intensities in at least one region. Across the three regions, high fishing intensity sites had predators that consumed a greater biomass of crustaceans, molluscs and echinoderms. At low fishing intensity sites, predators had diets comprising a greater biomass of cnidarians and teleosts, and a different assemblage of molluscs, crustaceans and fishes. These changes in diet suggest that there may have been a shift in the structure of the benthic community following intensive fishing. Analysis of predator diets is a useful tool to help identify changes in the benthic community composition after exposure to fishing. This study also provided valuable diet information on a range of abundant generalist benthic predators to improve the ecosystem modelling tools needed to support ecosystem-based fisheries management.

  14. Bottom trawling affects fish condition through changes in the ratio of prey availability to density of competitors

    DEFF Research Database (Denmark)

    Hiddink, Jan Geert; Moranta, Joan; Balestrini, Stephen

    2016-01-01

    and applications. Our study indicates that fish production may be maximized by keeping bottom-trawling intensities relatively low, although this may negatively ffect the economically more important Nephrops fishery. The effects of bottom trawls may be mitigated by switching to gears, which affect prey availability...

  15. Overview of current marine juvenile salmon research by the United States

    Science.gov (United States)

    Helle, John H.; Eisner, L.B.; Farley, Edward V.; Martinson, Ellen C.; Martinson, Angela; Moss, Jamal H.; Murphy, James M.; Orsi, Joseph A.; Sturdevant, Mollly V.; Wertheimer, Alex C.; Wing, Bruce L.; Brodeur, R.D.; Emmett, Robert; Bucher, Cynthia; MacFarlane, Bruce; Harding, Jeff; Ammann, Arnold; Zimmerman, Christian E.

    2007-01-01

    A history of juvenile salmon research on Pacific salmon in coastal areas conducted by the United States (U.S.) was published by Brodeur et al. (2003). Presently, juvenile Pacific salmon research in the U.S. occurs in the coastal areas of all of the Pacific states: California, Oregon, Washington, and Alaska (Fig. 1). Major objectives of this research are to understand how dynamics in marine ecosystems influence migration, distribution, growth, and survival of juvenile salmon during their early ocean residence. Several large-scale studies in coastal areas from California to Alaska are currently being conducted by the National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries Service (NMFS), in collaboration with university and state scientists. Studies off California are operated by the Southwest Fisheries Science Center, Santa Cruz Laboratory in Santa Cruz, California and University of California Santa Cruz. Studies off Oregon and Washington are operated by the Northwest Fisheries Science Center, Newport Laboratory and Oregon State University in Newport, Oregon. Studies in the Gulf of Alaska, Bering Sea and in the seaward migration corridors in the coastal waters of southeastern Alaska are operated by the Alaska Fisheries Science Center, Auke Bay Laboratory in Juneau, Alaska, in collaboration with Alaska Department of Fish and Game, University of Alaska Fairbanks, Bering Sea Fishermen’s Association, and Yukon River Drainage Fishermen’s Association. In addition to these large studies, smaller estuarine studies on juvenile salmon occur in northwestern Alaska in Kuskokwim Bay by the U.S. Geological Survey (Anchorage) and University of Alaska Fairbanks (Juneau), and, in Norton Sound by LGL Alaska Research Associates and Norton Sound Economic Development Corporation both headquartered in Anchorage (Fig. 1). The estuarine studies on juvenile salmon in Alaska operate in shallow water and a variety of gear is used to capture salmon. A small trawl

  16. Trawling bats exploit an echo-acoustic ground effect

    Directory of Open Access Journals (Sweden)

    Sandor eZsebok

    2013-04-01

    Full Text Available A water surface acts not only as an optic mirror but also as an acoustic mirror. Echolocation calls emitted by bats at low heights above water are reflected away from the bat, and hence the background clutter is reduced. Moreover, targets on the surface create an enhanced echo. Here, we formally quantified the effect of the substrate and target height on both target detection and –discrimination in a combined laboratory and field approach with Myotis daubentonii. In a two-alternative, forced-choice paradigm, the bats had to detect a mealworm and discriminate it from an inedible dummy (20 mm PVC disc. Psychophysical performance was measured as a function of height above either smooth substrates (water or PVC or above a clutter substrate (artificial grass. At low heights above the clutter substrate (10, 20 or 35 cm, the bats’ detection performance was worse than above a smooth substrate. At a height of 50 cm, the substrate structure had no influence on target detection. Above the clutter surface, also target discrimination was significantly impaired with decreasing target height. A detailed analysis of the bats’ echolocation calls during target approach shows that above the clutter substrate, the bats produce calls with significantly higher peak frequency. Flight-path reconstruction revealed that the bats attacked an object from below over water but from above over a clutter substrate.These results are consistent with the hypothesis that trawling bats exploit an echo-acoustic ground effect, in terms of a spatio-temporal integration of direct reflections with indirect reflections from the water surface, to optimize prey detection and –discrimination not only for prey on the water but also for some range above.

  17. Trawling bats exploit an echo-acoustic ground effect.

    Science.gov (United States)

    Zsebok, Sandor; Kroll, Ferdinand; Heinrich, Melina; Genzel, Daria; Siemers, Björn M; Wiegrebe, Lutz

    2013-01-01

    A water surface acts not only as an optic mirror but also as an acoustic mirror. Echolocation calls emitted by bats at low heights above water are reflected away from the bat, and hence the background clutter is reduced. Moreover, targets on the surface create an enhanced echo. Here, we formally quantified the effect of the surface and target height on both target detection and -discrimination in a combined laboratory and field approach with Myotis daubentonii. In a two-alternative, forced-choice paradigm, the bats had to detect a mealworm and discriminate it from an inedible dummy (20 mm PVC disc). Psychophysical performance was measured as a function of height above either smooth surfaces (water or PVC) or above a clutter surface (artificial grass). At low heights above the clutter surface (10, 20, or 35 cm), the bats' detection performance was worse than above a smooth surface. At a height of 50 cm, the surface structure had no influence on target detection. Above the clutter surface, also target discrimination was significantly impaired with decreasing target height. A detailed analysis of the bats' echolocation calls during target approach shows that above the clutter surface, the bats produce calls with significantly higher peak frequency. Flight-path reconstruction revealed that the bats attacked an target from below over water but from above over a clutter surface. These results are consistent with the hypothesis that trawling bats exploit an echo-acoustic ground effect, in terms of a spatio-temporal integration of direct reflections with indirect reflections from the water surface, to optimize prey detection and -discrimination not only for prey on the water but also for some range above.

  18. Aspects of the biology of the Atlantic Midshipman, Porichthys porosissimus (Teleostei, Batrachoididae: an important by-catch species of shrimp trawling off southern Brazil

    Directory of Open Access Journals (Sweden)

    Marcelo Vianna

    2000-01-01

    Full Text Available Trawl fishing for pink shrimp (Farfantepenaeus brasiliensis and F. paulensis catches large quantities of by-catch fish, discarded due to their having no commercial vaue. As these species have rarely been studied, the impact of fisheries on these populations is not known. This contribution studies the biology of a species of no commercial value, the Atlantic midshipman Porichthys porosissimus. The last haul /Tom a commercial trawler, operating on the northern coast of São Paulo State and the southern coast of Rio de Janeiro State, was preserved (/Tom being discarded and identified at the species leveI. It was observed that this fishery affects the juvenile population which is intluenced by the seasonal variation of the water masses. Growth parameters were estimated: L∞ = 37.0 cm, K = 0.285 year-1. Instantaneous mortality coefficients were estimated: 2=2.14, M=0.63, F= 1.51, S= 11.8 and E=0.71. Considering the intensive activity of the shrimp trawl tleet operating in this area, the deleterious action of trawling is considered as of high impact. The stock management measures applied for pink shrimp are without effect regarding P. porosissimus. which has its spawning period before the closed season and its recruitment peak after it. The results show overfishing and the need to apply measures to reduce trawling action, such as adequate policies, introduction of selectivity devices and the creation of exclusion zones for trawl fishing.A pesca de arrasto para a captura do camarão-rosa (Fm:fantepenaeus brasi/iensis e F. paulensis captura grande quantidade de peixes considerados fauna acompanhante que são descartados por não possuírem valor comercial. Assim, pouco aparecem em trabalhos de biologia pesqueira com dados de desembarque, sendo a ação pesqueira sobre estas populações pouco conhecida. Neste estudo, um arrasto mensal de um barco de pesca foi desembarcado sem que nada do material capturado fosse descartado. Analisou-se Porichthys

  19. Estimation of seafloor impact from demersal trawls, seines and dredges based on gear design and dimensions

    DEFF Research Database (Denmark)

    Eigaard, Ole Ritzau; Bastardie, Francois; Breen, Michael

    a different approach using the gear itself (design and dimensions) for understanding and estimation of the physical interactions with the seafloor at the individual fishing operation level. With reference to the métier groupings of EU logbooks, we defined 17 distinct towed gear groups in European waters (11...... otter trawl groups, 3 beam trawl groups, 2 demersal seine groups, and 1 dredge group), for which we established seafloor “footprints”. The footprint of a gear was defined as the relative contribution from individual larger gear components, such as the trawl doors, sweeps and ground gear, to the total...... types based on a review of the scientific literature. For each defined gear group a vessel-size (kW or total length) – gear size (total gear width or circumference) relationship was estimated to enable the prediction of gear footprint area and sediment penetration from vessel size. The implications...

  20. Towards a framework for the quantitative assessment of trawling impact on the seabed and benthic ecosystem

    DEFF Research Database (Denmark)

    Rijnsdorp, A. D.; Bastardie, Francois; Bolam, S.G.

    2016-01-01

    and considers the physical effects of trawl gears on the seabed, on marine taxa, and on the functioning of the benthic ecosystem. Within the frame- work, a reductionist approach is applied that breaks down a fishing gear into its components, and a number of biological traits are chosen to de- termine either...... the vulnerability of the benthos to the impact of that gear component, or to provide a proxy for their ecological role. The approach considers gear elements, such as otter boards, twin trawl clump, and groundrope, and sweeps that herd the fish. The physical impact of these ele- ments on the seabed, comprising...... scraping of the seabed, sediment mobilization, and penetration, is a function of the mass, size, and speed of the individual component. The impact of the elements on the benthic community is quantified using a biological-trait approach that considers the vulnerability of the benthic community to trawl...

  1. Environmental DNA from seawater samples correlate with trawl catches of Subarctic, deepwater fishes

    DEFF Research Database (Denmark)

    Thomsen, Philip Francis; Møller, Peter Rask; Sigsgaard, Eva Egelyng

    2016-01-01

    Remote polar and deepwater fish faunas are under pressure from ongoing climate change and increasing fishing effort. However, these fish communities are difficult to monitor for logistic and financial reasons. Currently, monitoring of marine fishes largely relies on invasive techniques...... such as bottom trawling, and on official reporting of global catches, which can be unreliable. Thus, there is need for alternative and non-invasive techniques for qualitative and quantitative oceanic fish surveys. Here we report environmental DNA (eDNA) metabarcoding of seawater samples from continental slope...... depths in Southwest Greenland. We collected seawater samples at depths of 188-918 m and compared seawater eDNA to catch data from trawling. We used Illumina sequencing of PCR products to demonstrate that eDNA reads show equivalence to fishing catch data obtained from trawling. Twenty-six families were...

  2. SEBARAN HORIZONTAL JUVENIL UDANG DI PERAIRAN LAGUNA SEGARA ANAKAN

    Directory of Open Access Journals (Sweden)

    Didik Wahyu Hendro Tjahjo

    2016-03-01

    Full Text Available Terdapat sembilan spesies udang ekonomis penting di  perairan Cilacap dan sekitarnya yang termasuk komoditas perikanan tangkap, dimana sebanyak 34% dari total udang yang tertangkap nelayan, menetas dan dibesarkan di kawasan laguna Segara Anakan. Kondisi ini mengisyaratkan agar dalam pengelolaan perikanan, Segara Anakan perlu mendapat perhatian termasuk aspek ekologis perairan. Untuk itu dilakukan penelitian dengan tujuan untuk mengkaji kelimpahan dan sebaran horizontal juvenil udang  serta preferensi habitatnya di perairan Laguna Segara Anakan. Penelitian lapang dilakukan sebanyak 3 kali frekuensi pengambilan sampel, yaitu pada April, September dan Desember 2012. Pengambilan sampel udang dilakukan dengan alat tangkap mini beam trawl secara terstratifikasi pada delapan titik stasiun pengamatan. Analisa data meliputi kelimpahan dan distribusi horizontal udang, serta preferensi habitatnya. Kelimpahan juvenil udang tertinggi ditemukan di stasiun Klaces dan terendah di stasiun Sapuregel Kecil, dimana nilainya berkisar antara 8-446 ekor/1000 m2 (udang penaeid 8-336 ekor/1000 m2. Post larva udang penaeid tampak dapat  menyesuaikan diri terhadap fluktuasi salinitas yang berkisar antara 2-35 ‰ hingga menjadi juvenil muda serta siap bermigrasi kembali ke laut hingga dewasa untuk melakukan siklus berikutnya. Dari data variasi kelimpahan dan pola sebaran juvenil udang diperoleh gambaran bahwa preferensi habitat bagi udang adalah tipe dasar perairan yang lembut (soft, biasanya terdiri dari campuran lumpur dan pasir.  Kelompok udang penaeid ini tersebar relatif merata di perairan laguna.   There are nine species of economically important shrimp in Cilacap water  which  belonging to  fisheries commodities, where as many as 34 % of the total shrimp caughted are hatched and raised in the Segara Anakan lagoon. This condition implies that in fisheries management option, Segara Anakan lagoon  include its ecological aspects need attention.  In this

  3. Near coastal ocean attributes of salmon - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  4. Chlorophyll and Nutrient Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  5. Bird Distribution and Abundance - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  6. Evaluation of Low and High Frequency Sound for Enhancing Fish Screening Facilities to Protect Outmigrating Salmonids.

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Robert P.; Neitzel, Duane A.; Mavros, William V.

    1998-02-01

    evaluations needed to produce, deploy or install sound equipment at existing or planned fish screening facilities. The focus of this study is to determine if fish, specifically juvenile salmonids, can be guided by sound.

  7. Salmon lice – impact on wild salmonids and salmon aquaculture

    Science.gov (United States)

    Torrissen, O; Jones, S; Asche, F; Guttormsen, A; Skilbrei, O T; Nilsen, F; Horsberg, T E; Jackson, D

    2013-01-01

    Salmon lice, Lepeophtheirus salmonis, are naturally occurring parasites of salmon in sea water. Intensive salmon farming provides better conditions for parasite growth and transmission compared with natural conditions, creating problems for both the salmon farming industry and, under certain conditions, wild salmonids. Salmon lice originating from farms negatively impact wild stocks of salmonids, although the extent of the impact is a matter of debate. Estimates from Ireland and Norway indicate an odds ratio of 1.1:1-1.2:1 for sea lice treated Atlantic salmon smolt to survive sea migration compared to untreated smolts. This is considered to have a moderate population regulatory effect. The development of resistance against drugs most commonly used to treat salmon lice is a serious concern for both wild and farmed fish. Several large initiatives have been taken to encourage the development of new strategies, such as vaccines and novel drugs, for the treatment or removal of salmon lice from farmed fish. The newly sequenced salmon louse genome will be an important tool in this work. The use of cleaner fish has emerged as a robust method for controlling salmon lice, and aquaculture production of wrasse is important towards this aim. Salmon lice have large economic consequences for the salmon industry, both as direct costs for the prevention and treatment, but also indirectly through negative public opinion. PMID:23311858

  8. A global assessment of salmon aquaculture impacts on wild salmonids.

    Directory of Open Access Journals (Sweden)

    Jennifer S Ford

    2008-02-01

    Full Text Available Since the late 1980s, wild salmon catch and abundance have declined dramatically in the North Atlantic and in much of the northeastern Pacific south of Alaska. In these areas, there has been a concomitant increase in the production of farmed salmon. Previous studies have shown negative impacts on wild salmonids, but these results have been difficult to translate into predictions of change in wild population survival and abundance. We compared marine survival of salmonids in areas with salmon farming to adjacent areas without farms in Scotland, Ireland, Atlantic Canada, and Pacific Canada to estimate changes in marine survival concurrent with the growth of salmon aquaculture. Through a meta-analysis of existing data, we show a reduction in survival or abundance of Atlantic salmon; sea trout; and pink, chum, and coho salmon in association with increased production of farmed salmon. In many cases, these reductions in survival or abundance are greater than 50%. Meta-analytic estimates of the mean effect are significant and negative, suggesting that salmon farming has reduced survival of wild salmon and trout in many populations and countries.

  9. An Improved Backstepping-Based Controller for Three-Dimensional Trajectory Tracking of a Midwater Trawl System

    Directory of Open Access Journals (Sweden)

    Zhao Yan

    2016-01-01

    Full Text Available An improved backstepping control method for three-dimensional trajectory tracking of a midwater trawl system is investigated. A new mathematical model of the trawl system while considering the horizontal expansion effect of two otter boards is presented based on the Newton Euler method. Subsequently, an active path tracking strategy of the trawl system based on the backstepping method is proposed. The nonstrict feedback characteristic of the proposed model employs a control allocation method and several parallel nonlinear PID (Proportion Integration Differentiation controllers to eliminate the high-order state variables. Then, the stability analysis by the Lyapunov Stability Theory shows that the proposed controller can maintain the stability of the trawl system even with the presence of external disturbances. To validate the proposed controller, a simulation comparison with a linear PID controller was conducted. The simulation results illustrate that the improved backstepping controller is effective for three-dimensional trajectory tracking of the midwater trawl system.

  10. Indirect effects of otter trawling on the condition and trophic level of Nephrops and flatfish in the Kattegat

    DEFF Research Database (Denmark)

    Hiddink, Jan Geert; Balestrin, Stephen; Moranta, Joan

    in the Kattegat (Sweden and Denmark). The results show that the abundance and body size of Nephrops was much higher in the fully closed areas, whereas that of the flatfish was less affected. The condition and trophic level for Nephrops were highest on intensively trawled areas suggesting that trawling reduces......The fishing gear used in bottom trawl fisheries cause mortality of benthic invertebrates and this can decrease the long-term availability of prey to exploited fish species by reducing the abundance of benthic invertebrates. Alternatively, low trawling levels could increase food production...... the condition (as weight-atlength) and trophic level of the fish Pleuronectes platessa, Limanda limanda, Hippoglossoides platessoides and the crustacean Nephrops norvegicus in an area with strong variation in commercial otter-trawling effort owing to the presence of MPAs with different levels of protection...

  11. BIOCHEMICAL AND MORPHOMETRIC PARAMETERS OF PRE-LARVAE OF THREE SALMONIDS SPECIES AT ONE-DAY AGE

    Directory of Open Access Journals (Sweden)

    Ye. Barylo

    2016-06-01

    Full Text Available Purpose. To study and analyze the morphometric and some biochemical parameters of pre-larval brown trout, rainbow trout and brook trout in post-embryonic period under the conditions of "Rybnyi Potik” farm in the Transcarpathian region for further use of the obtained data in scientific and practical works related to the cultivation of the juveniles of valuable salmonid species. Methodology. One-day free embryos (pre-larvae of brown trout, rainbow trout and brook trout we used as study materials. Morphometric parameters we studied by the methods of N. O. Lange, E. N. Dmitrieva. The content of total lipids was determined in accordance with Folch. in the tissuesm, which were taken for biochemical studies. Separate classes of lipids were received by thin layer chromatography. Findings. We carried out a comparative analysis of morphometric measurements and biochemical parameters of one-day pre-larval brown trout, rainbow trout and brook trout based on the obtained data. We investigated morphometric and biochemical specific features of pre-larvae in post-embryonic period and showed the species differences of morphometric measurements. Significant differences were observed between the content of lipids in the body and yolk sac of free embryos. In particular, a higher content of phospholipids and triglycerides was observed in the body of brook trout compared to brown trout. We also recorded higher contents of mono- and diacylglycerols, free cholesterol, non-etherified fatty acids (NEFA, triacylglycerols and cholesterol esters in the yolk sac of brook trout. Compared to brown trout, rainbow trout had a significant increase in mono- and diacylglycerols, free cholesterol and NEFA in both body and yolk sac as well higher levels of total lipids, triacylglycerols and cholesterol esters were registered in yolk sac. Originality. For the first time we carried out and compared the specific features of pre-larval brown trout, rainbow trout and brook trout in the

  12. Bio-economic evaluation of implementing trawl fishing gear with different selectivity

    DEFF Research Database (Denmark)

    Kronbak, Lone Grønbæk; Nielsen, J. Rasmus; Jørgensen, Ole A.

    2009-01-01

    for the fish stocks, fishermen and society. The bio-economic evaluation is applied to the case of the Danish trawl fishery in Kattegat and Skagerrak, which experiences a high level of discards and bycatches of several species. Four different kinds of selectivity scenarios are evaluated in comparison...... with a baseline. The results from the evaluation are indicators for the consequences on ecological and economic levels. The results show that implementation of different selective fishing gear in the Kattegat and Skagerrak mixed trawl fisheries generally implies a trade off over time between rebuilding the stocks...

  13. Antarctic krill; assessment of mesh size selectivity and escape mortality from trawls

    DEFF Research Database (Denmark)

    Krafft, Bjørn A.; Krag, Ludvig Ahm; Herrmann, Bent;

    2015-01-01

    This working paper presents the aims and methodology for a three-year-project (commenced in 2015) assessing size selectivity and escape mortality of Antarctic krill from trawl nets. The project is widely based on acquired experiences from a completed study Net Escapement of Antarctic krill...... in Trawls (NEAT), presented in WG-EMM 2012/24, WGEMM 2013/34, WG-EMM 2014/14 and WG-EMM 2014/16. Funding is provided by the Norwegian Research Council and ship-time for executing the field-experiments is offered free-of-charge by two Norwegian commercial fishing companies; Olympic Seafood AS and Aker Bio...

  14. Evaluation of Juvenile Fish Bypass and Adult Fish Facilities at Water Diversions in the Umatilla River; 1992 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, Suzanne M.

    1993-03-01

    We report on our progress from October 1991 through September 1992 in evaluating juvenile fish bypass facilities at Three Mile Falls and Westland dams on the Umatilla River. We also report on our progress from October 1991 through June 1992 in evaluating adult fish passage in the lower Umatilla River and adult fish passage facilities at Three Mile Falls Dam. The study is a cooperative effort by the Oregon Department of Fish and Wildlife (ODFW) and the Confederated Tribes of the Umatilla Indian Reservation (CTUIR). These are the study objectives addressed by ODFW and CTUIR: (1) Report A (ODFW): To evaluate the juvenile fish bypass facility in the West Extension Irrigation District Canal at Three Mile Falls Dam and document juvenile salmonid passage through the juvenile fish bypass facility and east-bank adult fish ladder. To measure velocity and develop trap designs at Westland Dam. (2) Report B (CTUIR): To examine the passage of adult salmonids at Three Mile Falls Dam. The study is part of a program to rehabilitate anadromous fish stocks in the Umatilla River Basin, including restoration of coho salmon (Oncorhynchus kisutch) and chinook salmon (Oncorhynchus tshawytscha), as well as enhancement of summer steelhead (Oncorhynchus mykiss).

  15. Climate regimes and water temperature changes in the Columbia River: bioenergetic implications for predators of juvenile salmon

    Science.gov (United States)

    Petersen, J.H.; Kitchell, J.F.

    2001-01-01

    We examined how climatic regime shifts may have affected predation rates on juvenile Pacific salmonids (Oncorhynchus spp.) by northern squawfish (Ptychocheilus oregonensis, also called northern pikeminnow), smallmouth bass (Micropterus dolomieu), and walleye (Stizostedion vitreum) in the Columbia River. During 1933-1996, oceanic, coastal, and freshwater indices of climate were highly correlated, and an index for the Columbia River Basin suggested that climate shifts may have occurred about 1946, 1958, 1969, and 1977. Summer water temperature varied as much as 2??C between climate periods. We used a bioenergetics model for northern squawfish, the most important piscivore, to predict that predation on salmonids would have been 26-31% higher during two periods with relatively warm spring-summer water temperatures (1933-1946, 1978-1996) than during an extremely cold period (1947-1958). Predicted predation rates of northern squawfish were 68-96% higher in the warmest year compared with the coldest year. Predation rates of smallmouth bass and walleye on juvenile salmonids varied among climate periods similar to rates predicted for northern squawfish. Climatic effects need to be understood in both freshwater and nearshore marine habitats, since growth rates of salmon populations are especially sensitive to mortality during early life stages.

  16. Seasonal Shift of Bycatch in the Artisanal Shrimp Trawl Fishery of the Gulf of Salamanca, Caribbean Sea of Colombia

    Directory of Open Access Journals (Sweden)

    Luis Orlando Duarte

    2013-06-01

    Full Text Available Bycatch assessments in trawl fisheries have been mainly referred to an annual scale, ignoring possible seasonal variations. In the Gulf of Salamanca, an artisanal shrimp trawl fleet operates recently and this study evaluates its bycatch for first time, considering the climatic and oceanographic seasonality that dominates the region (runoff and upwelling. 90 hauls in the calm or rainy season (November 2010 and 86 in the windy season (April 2011 were sampled on board of fishing boats. The bycatch to shrimp ratio was 2,69 (2,37 -3,21, 95 % CI and 6,37 (5,10 – 8,24, 95 % CI for the calm season and windy season respectively. We recorded a total of 101 taxa, with a large number of juveniles. The community structure of bycatch differed between seasons (ANOSIM, pStellifer spp., Symphurus caribbeanus y Callinectes sapidus, whereas, in addition, the calm season was characterized by Cathorops mapale, Anchovia clupeoides, Trichiurus lepturus, and the windy season by Larimus breviceps, Cnidaria (jellyfish, Cetengraulis edentulus (Simper. The results showed a seasonal change in the bycatch, raising the need to implement monitoring programs and management measures that address that temporal variability. Negative ecological effects of this fishery prompt the use of mitigation strategies, involving fishermen, to balance social needs and the ecosystem conservation. CAMBIO ESTACIONAL EN LA FAUNA ACOMPAÑANTE DE LA PESQUERÍA ARTESANAL DE ARRASTRE DE CAMARÓN DEL GOLFO DE SALAMANCA, MAR CARIBE DE COLOMBIALa evaluación de la fauna acompañante en las pesquerías de arrastre se ha referido generalmente a una escala anual, ignorando eventuales variaciones estacionales. En el golfo de Salamanca, recientemente opera una flota artesanal de arrastre de camarón, cuya fauna acompañante es evaluada por primera vez en el presente estudio, considerando la estacionalidad climática y oceanográfica que domina la región (descargas continentales y surgencia

  17. Juvenile giant fibroadenoma

    Directory of Open Access Journals (Sweden)

    Vipul Yagnik

    2011-07-01

    Full Text Available Fibroadenomas are benign solid tumor associated with aberration of normal lobular development. Juvenile giant fibroadenoma is usually single and >5 cm in size /or >500 gms in weight. Important differential diagnoses are: phyllodes tumor and juvenile gigantomastia. Simple excision is the treatment of choice.

  18. Renewing Juvenile Justice

    Science.gov (United States)

    Macallair, Daniel; Males, Mike; Enty, Dinky Manek; Vinakor, Natasha

    2011-01-01

    The Center on Juvenile and Criminal Justice (CJCJ) was commissioned by Sierra Health Foundation to critically examine California's juvenile justice system and consider the potential role of foundations in promoting systemic reform. The information gathered by CJCJ researchers for this report suggests that foundations can perform a key leadership…

  19. Philanthropist in Juvenile Reformatory

    Institute of Scientific and Technical Information of China (English)

    HAN NIU

    2007-01-01

    @@ On the afternoon of February 1, 2007, Chen Guangbiao, a noted philanthropist, found himself in the Jiangsu Provincial Juvenile Reformatory in Jurong City for a ceremony to donate two buses, 100 computers, and 100 desks and 100 chairs for the juvenile offenders to use in their study.

  20. Parenting and juvenile delinquency

    NARCIS (Netherlands)

    Hoeve, Machteld

    2008-01-01

    Juvenile delinquency is a noteworthy problem. This thesis addressed the association between parenting and juvenile delinquency by analyzing the concepts of parenting adopted in family research in relation to criminological concepts and measures of delinquent behavior. Four studies were conducted. Th

  1. Juvenile Confinement in Context

    Science.gov (United States)

    Mendel, Richard A.

    2012-01-01

    For more than a century, the predominant strategy for the treatment and punishment of serious and sometimes not-so-serious juvenile offenders in the United States has been placement into large juvenile corrections institutions, alternatively known as training schools, reformatories, or youth corrections centers. America's heavy reliance on…

  2. Parenting and juvenile delinquency

    NARCIS (Netherlands)

    Hoeve, Machteld

    2008-01-01

    Juvenile delinquency is a noteworthy problem. This thesis addressed the association between parenting and juvenile delinquency by analyzing the concepts of parenting adopted in family research in relation to criminological concepts and measures of delinquent behavior. Four studies were conducted. Th

  3. Molecular epidemiology of salmonid alphavirus (SAV subtype 3 in Norway

    Directory of Open Access Journals (Sweden)

    Jansen Mona D

    2010-08-01

    Full Text Available Abstract Background Pancreas disease (PD is a viral fish disease which in recent years has significantly affected Norwegian salmonid aquaculture. In Norway, the aetiological agent salmonid alphavirus (SAV has been found to be represented by the subtype 3 only. SAV subtype 3 has in previous analyses been found to show a lower genetic divergence than the subtypes found to cause PD in Ireland and Scotland. The aim of this study was to evaluate the nucleotide (nt and amino acid divergence and the phylogenetic relationship of 33 recent SAV subtype 3 sequences. The samples from which the sequences were obtained originated from both PD endemic and non-endemic regions in an attempt to investigate agent origin/spread. Multiple samples throughout the seawater production phase from several salmonid populations were included to investigate genetic variation during an outbreak. The analyses were mainly based on partial sequences from the E2 gene. For some samples, additional partial 6 K and nsP3 gene sequences were available. Results The nucleotide divergence for all gene fragments ranged from total identity (0.0% divergence to 0.45% (1103 nt fragment of E2, 1.11% (451 nt fragment of E2, 0.94% (6 K and 0.28% (nsP3. This low nucleotide divergence corresponded well to previous reports on SAV 3 sequences; however the observed divergence for the short E2 fragment was higher than that previously reported. When compared to SAVH20/03 (AY604235, amino acid substitutions were detected in all assessed gene fragments however the in vivo significance of these on for example disease outbreak mortality could not be concluded on. The phylogenetic tree based on the 451 nt E2 fragment showed that the sequences divided into two clusters with low genetic divergence, representing only a single SAV subtype. Conclusions The analysed sequences represented two clusters of a single SAV subtype; however some of the observed sequence divergence was higher than that previously reported

  4. Juvenile mammary papillomatosis; Papilomatosis juvenil mamaria

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, M.; Jimenez, A. V. [Hospital Reina Sofia. Cordoba (Spain)

    2001-07-01

    Juvenile mammary papillomatosis is a benign proliferative disease of young patients, generally under 30 years of age. The most frequent clinical presentation is the existence of an elastic and mobile lymph node of the breast. Anatomopathologically, it is characterized because it presents ductal epithelial hyperplasia, sometimes with marked atypia, and there are numerous cysts having different sizes among the findings. It has been associated with an increase in the incidence of breast cancer, both in the patient herself as well as her family. We review the literature on the subject and present the mammographic and ultrasonographic findings of a 22 year old woman diagnosed of juvenile mammary papillomatosis. (Author) 12 refs.

  5. Modelling marine ecosystem response to climate change and trawling in the North Sea

    NARCIS (Netherlands)

    van der Molen, J.; Aldridge, J.N.; Coughlan, C.; Parker, E.R.; Stephens, D; Ruardij, P.

    2013-01-01

    The marine ecosystem response to climate change and demersal trawling was investigated using the coupled hydrodynamic-biogeochemical water column model GOTM-ERSEM-BFM for three contrasting sites in the North Sea. Climate change forcing was derived from the HadRM3-PPE-UK regional climate model for

  6. 76 FR 54887 - Fisheries Off West Coast States; Pacific Coast Groundfish Fishery Management Plan; Trawl...

    Science.gov (United States)

    2011-09-02

    ... hardware and software requirements for e- tickets to reflect more current computer operating systems and... procedures for the initial issuance of permits, endorsements, quota share, and catch history assignments... history assignment from one limited entry trawl endorsed permit to another. These trailing actions are...

  7. New approaches to the reduction of non-target mortality in beam trawling

    NARCIS (Netherlands)

    Marlen, van B.; Bergman, M.J.N.; Groenewold, S.; Fonds, M.

    2005-01-01

    This paper presents experiments with modified beam trawls aimed at reducing discard rates and direct mortality of benthic in-fauna and epi-fauna without affecting the level of landings. Drop-out panels made of large meshes in the belly of the net were effective in reducing by-catch, but the penalty

  8. Improving the effectiveness of escape windows in directed Norway lobster Nephrops norvegicus trawl fisheries

    DEFF Research Database (Denmark)

    Madsen, Niels; Holst, René; Frandsen, Rikke

    2012-01-01

    A substantial improvement in the bycatch selectivity of Norway lobster Nephrops norvegicus trawls is required, particularly with respect to cod Gadus morhua , whose stocks are at low levels in several areas. Conventional escape windows are not adequate to properly release cod and other bycatch sp...

  9. Species selectivity in different sized topless trawl designs: Does size matter?

    DEFF Research Database (Denmark)

    Krag, Ludvig Ahm; Herrmann, Bent; Karlsen, Junita Diana;

    2015-01-01

    Most demersal trawl fisheries are conducted in a multispecies setting, and the catch consists of severaldifferent species. An inherent challenge in such fisheries is to provide both biologically and economicallysustainable exploitation of individually fluctuating stocks and vessel- or fleet-speci...

  10. A 'simple anterior fish excluder' (SAFE for mitigating penaeid-trawl bycatch.

    Directory of Open Access Journals (Sweden)

    Matthew J McHugh

    Full Text Available Various plastic strips and sheets (termed 'simple anterior fish excluders'-SAFEs were positioned across the openings of penaeid trawls in attempts at reducing the unwanted bycatches of small teleosts. Initially, three SAFEs (a single wire without, and with small and large plastic panels were compared against a control (no SAFE on paired beam trawls. All SAFEs maintained targeted Metapenaeus macleayi catches, while the largest plastic SAFE significantly reduced total bycatch by 51% and the numbers of Pomatomus saltatrix, Mugil cephalus and Herklotsichthys castelnaui by up to 58%. A redesigned SAFE ('continuous plastic' was subsequently tested (against a control on paired otter trawls, significantly reducing total bycatch by 28% and P. saltatrix and H. castelnaui by up to 42%. The continuous-plastic SAFE also significantly reduced M. macleayi catches by ~7%, but this was explained by ~5% less wing-end spread, and could be simply negated through otter-board refinement. Further work is required to refine the tested SAFEs, and to quantify species-specific escape mechanisms. Nevertheless, the SAFE concept might represent an effective approach for improving penaeid-trawl selectivity.

  11. Twin-truss system design for antarctic krill trawl processing ship

    Directory of Open Access Journals (Sweden)

    ZHOU Chungkai

    2017-05-01

    Full Text Available Aiming to improve the fishing efficiency of antarctic krill processing ships by averting the potential crushing of krill in the trawl to meet quality requirements, a twin-truss system design is proposed which has higher efficiency compared with the traditional system installed in ships. To simulate this design, an analysis of forces acting on the twin-truss structure is conducted under tethered and operating conditions using the structure model method, and an appropriate distance between trawl winch and truss structure, as well as the range for limiting the distance of the horizontal locating cable and truss structure, are obtained. It can also prevent the truss structure from breaking down, enabling the efficiency of trawling and horizontal locating cables during fishing operations. The simulation shows that the new twin-truss system design can improve the efficiency of trawl processing ships, whilst maintain the safety of the truss structure. This design can provide an optimal solution for the truss systems of national antarctic krill processing ships.

  12. NIS occurrence - Non-native species impacts on threatened and endangered salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The objectives of this project: a) Identify the distribution of non-natives in the Columbia River Basin b) Highlight the impacts of non-natives on salmonids c)...

  13. Anadromous Salmonids in the Delta: New Science 2006–2016

    OpenAIRE

    Perry, Russell W.; Buchanan, Rebecca A.; Brandes, Patricia L.; Burau, Jon R.; Israel, Joshua A.

    2016-01-01

    doi: http://dx.doi.org/10.15447/sfews.2016v14iss2art7 As juvenile salmon enter the Sacramento–SanJoaquin River Delta (“the Delta”) they disperse among its complex channel network where they are subject to channel-specific processes that affect their rate of migration, vulnerability to predation, feeding success, growth rates, and ultimately, survival. In the decades before 2006, tools available to quantify growth, dispersal, and survival of juvenile salmon in this complex c...

  14. Impacts of trawling on benthic macro-fauna and -flora of the Spencer Gulf prawn fishing grounds

    Science.gov (United States)

    Svane, Ib; Hammett, Zoe; Lauer, Peter

    2009-05-01

    The overall effects of trawling on benthic habitats and their assemblages are dependent on the distribution and intensity of trawl effort. The benthic habitats of the Spencer Gulf prawn trawling grounds are subjected to known variable levels of trawling disturbance recorded from fisher's logbooks. These habitats have not been quantitatively investigated. The aim of the study was firstly to characterise the macro-faunal and -floral assemblages and secondly, to comparatively assess trawl impact by testing the null hypothesis of no differences between five sites exposed to different intensity of trawl effort. The distribution and abundance of benthic macro-fauna and -flora were studied at two sampling resolutions by using beam trawl sampling (˜10,000 m 2) and underwater stereophotography (˜4.5 m 2) at five sites with different levels of trawl disturbance (effort). The results showed that the Spencer Gulf prawn trawling grounds are characterised by sandy sediments with a low content of silt and clay, with the exception of one site with very fine gravel. Biomass, abundance and cover of macro-fauna and -flora were generally low throughout, but with large differences among sites. Biomass, abundance and cover were found to be negatively correlated to both trawl hours from 1994-1998 and during the period of study. ANOSIM and SIMPER analyses using biomass, abundance and percentage cover as variables showed significant differences between sites with eight species or taxonomic groups contributing more than 10% to the observed similarity within sites. The two northern sites were dominated by sponges and the bearded mussel, Trichomya hirsutus, and the southern hammer oyster, Malleus meridianus. Other species that contributed to the similarity within sites were the ascidian, Polycarpa viridis, mobile epifauna (the blue swimmer crab, Portunus pelagicus, and the western king prawn, Penaeus (Melicertus) latisulcatus) and demersal fish species (Degens leatherjacket, Thamnaconus

  15. EFFECT OF NON-ESSENTIAL ELEMENTS (MERCURY. ARSENIC ON SALMONIDS (SALMONIDAE (REVIEW

    Directory of Open Access Journals (Sweden)

    І. Hrytsyniak

    2015-09-01

    Full Text Available Purpose. The problem of water ecosystem pollution with heavy metals achieved great actuality during recent years, both because of their significant distribution in environment, and wide spectrum of their toxic effects on fish organism. Much attention in modern scientific literature is given to the problem of the effects of heavy metals, including mercury and arsenic, on fish organism. However, investigations in this field are conducted mainly on cyprinids, while physiological and biochemical mechanisms of the effects of heavy metals on salmonids are less studied. According to this, the studies of the sources of heavy metals in water ecosystems, peculiarities of their action in salmonid organism on subcellular, cellular, tissue and organ levels, species and age-related peculiarities of the effects of heavy metals are of great scientific and practical importance. The purpose of this work is to review the mentioned problems. Findings. The work characterizes the effects of mercury and arsenic on salmonids on subcellular, cellular, tissue and organ levels. The article contains characteristic of conditions, under which toxic or lethal action of the mentioned xenobiotics on different species of salmonids was observed. Originality. The paper summarizes literature data concerning the effect of mercury and arsenic on salmonids. Attention is accented on the sources of the mentioned pollutants in surface waters, physiological and biochemical mechanisms of their effects on salmonids, and on factors, which determine the level of their toxicity. Lethal concentrations of mercury and arsenic to salmonids, depending on experiment duration, species and age-related peculiarities are presented. Practical value. Data presented in the review can be used for the explanation of physiological and biochemical mechanisms of the adaptation of salmonids to surface water pollution with heavy metals, diagnostics of fish pathologies caused by toxic effects of mercury and

  16. Juvenile Chinook Salmon abundance in the northern Bering Sea: Implications for future returns and fisheries in the Yukon River

    Science.gov (United States)

    Murphy, James M.; Howard, Kathrine G.; Gann, Jeanette C.; Cieciel, Kristin C.; Templin, William D.; Guthrie, Charles M.

    2017-01-01

    Juvenile Chinook Salmon (Oncorhynchus tshawytscha) abundance in the northern Bering Sea is used to provide insight into future returns and fisheries in the Yukon River. The status of Yukon River Chinook Salmon is of concern due to recent production declines and subsequent closures of commercial, sport, and personal use fisheries, and severe restrictions on subsistence fisheries in the Yukon River. Surface trawl catch data, mixed layer depth adjustments, and genetic stock mixtures are used to estimate juvenile abundance for the Canadian-origin stock group from the Yukon River. Abundance ranged from a low of 0.62 million in 2012 to a high of 2.58 million in 2013 with an overall average of 1.5 million from 2003 to 2015. Although abundance estimates indicate that average survival is relatively low (average of 5.2%), juvenile abundance was significantly correlated (r=0.87, p=0.005) with adult returns, indicating that much of the variability in survival occurs during early life-history stages (freshwater and initial marine). Juvenile abundance in the northern Bering Sea has increased since 2013 due to an increase in early life-history survival (average juveniles-per-spawner increased from 29 to 59). The increase in juvenile abundance is projected to produce larger runs and increased subsistence fishing opportunities for Chinook Salmon in the Yukon River as early as 2016.

  17. Synthesis of Biological Reports on Juvenile Fish Passage and Survival at Bonneville Dam through 2005

    Energy Technology Data Exchange (ETDEWEB)

    Ploskey, Gene R.; Johnson, Gary E.; Giorgi, Albert E.; Johnson, Richard L.; Stevenson, John R.; Schilt, Carl R.; Johnson, Peter N.; Patterson, Deborah S.

    2005-06-01

    This report describes a review of available literature on juvenile salmonid passage at Bonneville Dam from 1939 through 2005. Studies of interest included project-wide fish-passage efficiency (FPE) studies by radio telemetry and fixed-aspect hydroacoustics, fish survival studies (direct and indirect), FGE studies, powerhouse and unit (by netting, hydroacoustics, and radio telemetry), predation studies in the forebay and tailrace, behavioral studies on forebay approach and egress, and surface-bypass studies. The FPE effort will include a review of available distribution data (horizontal, diel, and vertical) for juvenile salmon. This study does not repeat the results of previous review and synthesis studies but cites them. Where no previous review exists for a subject area, all reports were reviewed and synthesized. The report includes an annotated bibliography summarizing each of the documents reviewed and a DVD disk containing all of the original papers and reports along with an HTML index to the documents.

  18. Performance Assessment of Suture Type in Juvenile Chinook Salmon Surgically Implanted with Acoustic Transmitters

    Energy Technology Data Exchange (ETDEWEB)

    Deters, Katherine A.; Brown, Richard S.; Carter, Kathleen M.; Boyd, James W.

    2009-02-27

    The objective of this study was to determine the best overall suture material to close incisions from the surgical implantation of Juvenile Salmon Acoustic Telemetry System (JSATS) acoustic microtransmitters in subyearling Chinook salmon Oncorhynchus tshawytscha. The effects of seven suture materials, four surgeons, and two water temperatures on suture retention, incision openness, tag retention, tissue inflammation, and tissue ulceration were quantified. The laboratory study, conducted by researchers at the Pacific Northwest National Laboratory, supports a larger effort under way for the U.S. Army Corps of Engineers, Portland District, aimed at determining the suitability of acoustic telemetry for estimating short- and longer-term (30-60 days) juvenile-salmonid survival at Columbia and Snake River dams and through the lower Columbia River.

  19. Trapping and Transportation of Adult and Juvenile Salmon in the Lower Umatilla River in Northeast Oregon: Umatilla River Basin Trap and Haul Program, October 1994-September 1995.

    Energy Technology Data Exchange (ETDEWEB)

    Zimmerman, Brian C.; Duke, Bill B.

    1995-09-01

    Threemile Falls Dam (Threemile Dam), located near the town of Umatilla, is the major collection and counting point for adult salmonids returning to the Umatilla River. Returning salmon and steelhead were collected at Threemile Dam from August 26, 1994 to June 27, 1995. A total of 1,531 summer steelhead (Oncorhynchus mykiss); 688 adult, 236 jack, and 368 subjack fall chinook (O. tshawvtscha); 984 adult and 62 jack coho (O. kisutch) ; and 388 adult and 108 jack spring chinook (O. tshawvtscha) were collected. All fish were trapped at the east bank facility. Of the fish collected, 971 summer steelhead; 581 adult and 27 jack fall chinook; 500 adult and 22 jack coho; and 363 adult and 61 jack spring chinook were hauled upstream from Threemile Dam. There were also 373 summer steelhead; 12 adult, 186 jack and 317 subjack fall chinook; 379 adult and 32 jack coho; and 15 adult and one jack spring chinook released at Threemile Dam. In addition, 154 summer steelhead were hauled to Bonifer and Minthorn for brood. The Westland Canal facility, located near the town of Echo, is the major collection point for outmigrating juvenile salmonids and steelhead kelts. The facility operated for a total of 179 days between December 2, 1994 and July 19, 1995. During that period, fish were bypassed back to the river 137 days and were trapped 42 days. Three steelhead kelts and an estimated 1,560 pounds of juvenile fish were transported from the Westland Canal trap to the Umatilla River boat ramp at rivermile 0.5. Approximately 98% of the fish transported this year were salmonids. The Threemile Dam west bank juvenile bypass began operating March 25, 1995 and was closed on June 16, 1995. The juvenile trap was operated by Oregon Department of Fish and Wildlife research personnel from April 1, 1995 through the summer to monitor juvenile outmigration.

  20. Cryopyrin-Associated Autoinflammatory Syndromes (CAPS) - Juvenile

    Science.gov (United States)

    ... Cryopyrin-Associated Autoinflammatory Syndrome (CAPS) (Juvenile) Dermatomyositis (Juvenile) Familial Mediterranean Fever (Juvenile) Fibromyalgia Giant Cell Arteritis Glucocorticoid-induced Osteoperosis ...

  1. Juvenil idiopatisk arthritis

    DEFF Research Database (Denmark)

    Herlin, Troels

    2002-01-01

    The new classification of juvenile idiopathic arthritis (JIA) is described in this review. Clinical characteristics divide JIA in to subtypes: systemic, oligoarticular (persistent and extended type), RF-positive and--negative polyarticular, enthesitis-related arthritis and psoriatic arthritis...

  2. Juvenile Rockfish Recruitment Cruise

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 1983, the groundfish analysis project began a series of yearly cruises designed to assess the annual abundance of juvenile rockfish along the central California...

  3. Juvenile Idiopathic Arthritis

    Science.gov (United States)

    ... Physical Therapy Regular Exercise en español Artritis idiopática juvenil It may begin with a swollen knuckle, a ... may suddenly appear and disappear, developing in one area and then another. High fevers that tend to ...

  4. Juvenile Sex Offenders.

    Science.gov (United States)

    Ryan, Eileen P; Otonichar, Joseph M

    2016-07-01

    Sexual offending by juveniles accounts for a sizable percentage of sexual offenses, especially against young children. In this article, recent research on female juvenile sex offenders (JSOs), risk factors for offending in juveniles, treatment, and the ways in which these youth may differ from general delinquents will be reviewed. Most JSOs do not go on to develop paraphilic disorders or to commit sex offenses during adulthood, and as a group, they are more similar to nonsexual offending juvenile delinquents than to adult sex offenders. Recent research has elucidated some differences between youth who commit sex offenses and general delinquents in the areas of atypical sexual interests, the use of pornography, and early sexual victimization during childhood.

  5. Juvenile Spondyloarthritis Treatment Recommendations

    OpenAIRE

    Tse, Shirley; Burgos-Vargas, Ruben; Colbert, Robert A

    2012-01-01

    No specific recommendations for the treatment of juvenile spondyloarthritis have been established. Important differences exist in how spondyloarthritis begins and progresses in children and adults, supporting the need for pediatric-specific recommendations. Recently published recommendations for the treatment of juvenile arthritis consider children with sacroiliitis in a separate group, and allow for more accelerated institution of a TNF inhibitor depending on disease activity and prognostic ...

  6. Parenting and juvenile delinquency

    OpenAIRE

    Hoeve, Machteld

    2008-01-01

    Juvenile delinquency is a noteworthy problem. This thesis addressed the association between parenting and juvenile delinquency by analyzing the concepts of parenting adopted in family research in relation to criminological concepts and measures of delinquent behavior. Four studies were conducted. The first study addressed a meta-analysis on parenting characteristics and styles in relation to delinquency. In this meta-analysis, previous manuscripts were systematically analyzed, computing mean ...

  7. 77 FR 11412 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Catcher Vessels Using Trawl...

    Science.gov (United States)

    2012-02-27

    ... a timely fashion and would delay the directed fishing closure of Pacific cod for CVs using trawl... Director, Office of Sustainable Fisheries, National Marine Fisheries Service. BILLING CODE 3510-22-P...

  8. 78 FR 18528 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Catcher Vessels Using Trawl...

    Science.gov (United States)

    2013-03-27

    ... a timely fashion and would delay the directed fishing closure of Pacific cod for CVs using trawl... Director, Office of Sustainable Fisheries, National Marine Fisheries Service. BILLING CODE 3510-22-P...

  9. Mothership Cost Earnings Data - Economic Data Collection for Monitoring the Economic Effects of the West Coast Groundfish Trawl Rationalization Program

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project was initiated in response to regulation 50 CFR 660.114, which mandates that economic data be collected from every participant in the trawl...

  10. Acoustic-Trawl Survey of Walleye Pollock on the Eastern Bering Sea Shelf (DY1407, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — National Marine Fisheries Service (NMFS), Alaska Fisheries Science Center (AFSC) conducted an acoustic-trawl (AT) stock assessment survey on the eastern Bering Sea...

  11. NPRB711 Quantification of unobserved injury and mortality of Bering Sea crabs due to encounters with trawls on the seafloor

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The potential for unobserved mortality of crabs encountering bottom trawls, but not captured, has long been a concern in the management of Bering Sea fisheries. We...

  12. AFSC/RACE/MACE: Results of 2014 Acoustic-trawl survey of the Shumagin Islands and Sanak Trough dy1401

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The survey’s primary objective was to collect acoustic data and trawl information to estimate midwater abundance and distribution of walleye pollock (Gadus...

  13. AFSC/RACE/SAP: Detailed Crab Data From NOAA Fisheries Service 2012 Chukchi Sea Bottom Trawl Surveys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains detailed crab data collected from the 2012 NOAA/NMFS/AFSC/RACE crab-groundfish bottom trawl survey of the Chukchi Sea. 71 survey stations were...

  14. A Cabled Acoustic Telemetry System for Detecting and Tracking Juvenile Salmon: Part 1. Engineering Design and Instrumentation

    Directory of Open Access Journals (Sweden)

    M. Brad Eppard

    2011-05-01

    Full Text Available In 2001 the U.S. Army Corps of Engineers, Portland District (OR, USA, started developing the Juvenile Salmon Acoustic Telemetry System, a nonproprietary sensing technology, to meet the needs for monitoring the survival of juvenile salmonids through eight large hydroelectric facilities within the Federal Columbia River Power System (FCRPS. Initial development focused on coded acoustic microtransmitters and autonomous receivers that could be deployed in open reaches of the river for detection of the juvenile salmonids implanted with microtransmitters as they passed the autonomous receiver arrays. In 2006, the Pacific Northwest National Laboratory began the development of an acoustic receiver system for deployment at hydropower facilities (cabled receiver for detecting fish tagged with microtransmitters as well as tracking them in two or three dimensions for determining route of passage and behavior as the fish passed at the facility. The additional information on route of passage, combined with survival estimates, is used by the dam operators and managers to make structural and operational changes at the hydropower facilities to improve survival of fish as they pass the facilities through the FCRPS.

  15. Growth and condition of juvenile coho salmon Oncorhynchus kisutch relate positively to species richness of trophically transmitted parasites.

    Science.gov (United States)

    Losee, J P; Fisher, J; Teel, D J; Baldwin, R E; Marcogliese, D J; Jacobson, K C

    2014-11-01

    The aims of this study were first, to test the hypothesis that metrics of fish growth and condition relate positively to parasite species richness (S(R)) in a salmonid host; second, to identify whether S(R) differs as a function of host origin; third, to identify whether acquisition of parasites through marine v. freshwater trophic interactions was related to growth and condition of juvenile salmonids. To evaluate these questions, species diversity of trophically transmitted parasites in juvenile coho salmon Oncorhynchus kisutch collected off the coast of the Oregon and Washington states, U.S.A. in June 2002 and 2004 were analysed. Fish infected with three or more parasite species scored highest in metrics of growth and condition. Fish originating from the Columbia River basin had lower S(R) than those from the Oregon coast, Washington coast and Puget Sound, WA. Parasites obtained through freshwater or marine trophic interactions were equally important in the relationship between S(R) and ocean growth and condition of juvenile O. kisutch salmon.

  16. Robust Optimal Output Tracking Control of A Midwater Trawl System Based on T-S Fuzzy Nonlinear Model

    Institute of Scientific and Technical Information of China (English)

    ZHOU Hua; CHEN Ying-long; YANG Hua-yong

    2013-01-01

    A robust optimal output tracking control method for a midwater trawl system is investigated based on T-S fuzzy nonlinear model.A simplified nonlinear mathematical model is first employed to represent a midwater trawl system,and then a T-S fuzzy model is adopted to approximate the nonlinear system.Since the strong nonlinearities and the external disturbance of the trawling system,a mixed H2/H∞ fuzzy output tracking control strategy via T-S fuzzy system is proposed to regulate the trawl depth to follow a desired trajectory.The trawl depth can be regulated by adjusting the winch velocity automatically and the tracking error can be minimized according to the robust optimal criterion.In order to validate the proposed control method,a computer simulation is conducted.The simulation results indicate that the proposed fuzzy robust optimal controller make the trawl net rapidly follow the desired trajectory under the model uncertainties and the external disturbance caused by wave and current.

  17. Fuzzy robust path tracking strategy of an active pelagic trawl system with coordinated ship and winch regulation

    Institute of Scientific and Technical Information of China (English)

    陈英龙; 周华; 赵勇刚; 侯交义

    2014-01-01

    A fuzzy robust path tracking strategy of an active pelagic trawl system with ship and winch regulation is proposed. First, nonlinear mathematic model of the pelagic trawl system was derived using Lagrange equation and further simplified as a low order model for the convenience of controller design. Then, an active path tracking strategy of pelagic trawl system was investigated to improve the catching efficiency of the target fish near the sea bottom. By means of the active tracking control, the pelagic trawl net can be positioned dynamically to follow a specified trajectory via the coordinated winch and ship regulation. In addition, considering the system nonlinearities, modeling uncertainties and the unknown exogenous disturbance of the trawl system model, a nonlinear robust H2/H∞controller based on Takagi-Sugeno (T-S) fuzzy model was presented, and the simulation comparison with linear robust H2/H∞controller and PID method was conducted for the validation of the nonlinear fuzzy robust controller. The nonlinear simulation results show that the average tracking error is 0.4 m for the fuzzy robust H2/H∞control and 125.8 m for the vertical and horizontal displacement, respectively, which is much smaller than linear H2/H∞ controller and the PID controller. The investigation results illustrate that the fuzzy robust controller is effective for the active path tracking control of the pelagic trawl system.

  18. Vocational Teachers' Role in Serving Juvenile Offenders.

    Science.gov (United States)

    Meers, Gary D.

    1983-01-01

    Educators need to understand the juvenile justice system to understand what juvenile offenders go through while completing their sentences. This article reviews cases and juvenile charge classifications, and presents a model for alternative sentencing options for juveniles. (JOW)

  19. Estimating seabed pressure from demersal trawls, seines, and dredges based on gear design and dimensions

    DEFF Research Database (Denmark)

    Eigaard, Ole Ritzau; Bastardie, Francois; Breen, Mike

    2016-01-01

    This study assesses the seabed pressure of towed fishing gears and models the physical impact (area and depth of seabed penetration) from trip-based information of vessel size, gear type, and catch. Traditionally fishing pressures are calculated top-down by making use of large-scale statistics...... trawl groups, two demersal seine groups, and one dredge group), for which we established gear “footprints”. The footprint of a gear is defined as the relative contribution from individual larger gear components, such as trawl doors, sweeps, and groundgear, to the total area and severity of the gear......'s impact. An industry-based survey covering 13 countries provided the basis for estimating the relative impact-area contributions from individual gear components, whereas sediment penetration was estimated based on a literature review. For each gear group, a vessel size–gear size relationship was estimated...

  20. Lost in translation? Multi-metric macrobenthos indicators and bottom trawling

    DEFF Research Database (Denmark)

    Gislason, Henrik; Bastardie, Francois; Dinesen, Grete E.

    2017-01-01

    The member states of the European Union use multi-metric macrobenthos indicators to monitor the ecological status of their marine waters in relation to the Water Framework and Marine Strategy Framework Directives. The indicators translate the general descriptors of ecological quality...... trawling. We use linear mixed effects models to analyze how bottom trawling intensity affects the indicators used in the Danish (Danish Quality Index, DKI) and Swedish (Benthic Quality Index, BQI) environmental monitoring programs in the Kattegat, the sea area between Sweden and Denmark. Using year...... in the directives into a single value of ecological status by combining indices of species diversity, species sensitivity and density. Studies and inter-calibration exercises have shown that the indicators respond to chemical pollution and organic enrichment, but little is known about their response to bottom...

  1. Tissue damage in salmonids caused by Halisidota argentata Packard

    Science.gov (United States)

    1956-01-01

    During the histological examination of a collection of wild and hatchery salmonids, a peculiar foreign body was occasionally observed in various organs, particularly in the viscera. These objects, usually accompanied by a focal inflammation, were observed in 10 of 75 samples of wild trout and salmon collected in Oregon and Washington and were believed to represent an unknown type of parasitism. Their identity remained obscure until a massive concentration was observed in the tissues of wild coho salmon, (Oncorhynchus kisutch), from Minter Creek on the Olympic peninsula of Washington and in hatchery coho salmon from the Minter Creek Biological Station. The distribution of the structures suggested the intestinal tract as a point of origin. Subsequent stomach examinations revealed small, partially digested insect fragments with many long, spine-covered hairs. The insects were identified as second or third instars of the lepidopteran larvae, Halisidota argentata Packard. The spine-covered hairs penetrated the stomach wall and produced the observed lesions by working in an apparent porcupine quill-fashion throughout the body of the fish.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-01-01

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

  3. Bio-economic evaluation of implementing trawl fishing gear with different selectivity

    DEFF Research Database (Denmark)

    Grønbæk Kronbak, Lone; Nielsen, J. Rasmus; Jørgensen, Ole A.

    2009-01-01

    with a baseline. The results from the evaluation are indicators for the consequences on ecological and economic levels. The results show that implementation of different selective fishing gear in the Kattegat and Skagerrak mixed trawl fisheries generally implies a trade off over time between rebuilding the stocks...... and economic loss. Moreover, the analysis shows that implementation of more selective gear is not always beneficial. (C) 2009 Elsevier Ltd. All rights reserved....

  4. Trunk asymmetry in juveniles

    Directory of Open Access Journals (Sweden)

    Triantafyllopoulos Georgios

    2008-09-01

    Full Text Available Abstract Background Trunk asymmetry (TA is a common phenomenon in children, but its incidence in juveniles is not known. The present cross sectional study reports TA in normal juveniles and provides data which describe the evolution of TA from early childhood to adolescence. Materials and methods The scoliometer readings in both standing and sitting forward bending position (FBP of 3301 children, (1645 boys, and 1656 girls aged from 3 to 9 years old were studied. TA was quantified by measuring angle of trunk rotation (ATR and children were categorized as symmetric (ATR = 0°, mild asymmetric (ATR 1° – 6° and severely asymmetric (ATR ≥ 7°. The difference of TA between standing and sitting FBP as well as differences between boys and girls in frequency of TA were also calculated. The scoliometer readings were analyzed by age to reveal at which age the juvenile pattern of TA changes into the adolescent one. Results 74.2% of boys and 77% of girls were symmetric (ATR = 0° in the thoracic region in standing FBP, while 82.7% of boys and 84.1% of girls were symmetric in the thoracic region in sitting FBP. Juvenile girls are more symmetric than boys but severe TA was found almost the same between the two genders. A significant reduction in the frequency of mild TA from standing into sitting FBP, in all the examined regions in both boys and girls was found, but in severe TA this reduction is very small. Analysing scoliometer readings by age it appears that significant TA changes take place between 8–9 years of age for boys and between 6–7 and 8–9 years for girls. TA in boys is changing into the adolescent pattern at a later age than in girls. Conclusion Juveniles were found more symmetric than adolescents, who were studied previously in a different study. Furthermore, juvenile girls were found more symmetric than boys. Juvenile TA pattern seems to be in accordance with the higher incidence of juvenile idiopathic scoliosis in boys. Furthermore

  5. Juvenile Incarceration and Health.

    Science.gov (United States)

    Barnert, Elizabeth S; Perry, Raymond; Morris, Robert E

    2016-03-01

    Addressing the health status and needs of incarcerated youth represents an issue at the nexus of juvenile justice reform and health care reform. Incarcerated youth face disproportionately higher morbidity and higher mortality compared to the general adolescent population. Dental health, reproductive health, and mental health needs are particularly high, likely as a result of lower access to care, engagement in high-risk behaviors, and underlying health disparities. Violence exposure and injury also contribute to the health disparities seen in this population. Further, juvenile incarceration itself is an important determinant of health. Juvenile incarceration likely correlates with worse health and social functioning across the life course. Correctional health care facilities allow time for providers to address the unmet physical and mental health needs seen in this population. Yet substantial challenges to care delivery in detention facilities exist and quality of care in detention facilities varies widely. Community-based pediatricians can serve a vital role in ensuring continuity of care in the postdetention period and linking youth to services that can potentially prevent juvenile offending. Pediatricians who succeed in understanding and addressing the underlying social contexts of their patients' lives can have tremendous impact in improving the life trajectories of these vulnerable youth. Opportunities exist in clinical care, research, medical education, policy, and advocacy for pediatricians to lead change and improve the health status of youth involved in the juvenile justice system.

  6. Identification and evaluation of shark bycatch in Georgia's commercial shrimp trawl fishery with implications for management

    Science.gov (United States)

    Belcher, C.N.; Jennings, C.A.

    2011-01-01

    Many US states have recreational and commercial fisheries that occur in nursery areas occupied by subadult sharks and can potentially affect their survival. Georgia is one of few US states without a directed commercial shark fishery, but the state has a large, nearshore penaeid shrimp trawl fishery in which small sharks occur as bycatch. During our 1995–1998 investigation of bycatch in fishery-dependent sampling events, 34% of 127 trawls contained sharks. This bycatch totalled 217 individuals from six species, with Atlantic sharpnose shark, Rhizoprionodon terraenovae (Richardson), the most common and finetooth shark, Carcharhinus isodon (Müller & Henle) and spinner shark, Carcharhinus brevipinna (Müller & Henle), the least common. The highest catch rates for sharks occurred during June and July and coincided with the peak months of the pupping season for many species. Trawl tow speed and tow time did not significantly influence catch rates for shark species. Gear configurations [net type, turtle excluder device (TED), bycatch reduction device] affected catch rates for shark species. Results of this study indicate gear restrictions, a delayed season opening, or reduced bar spacing on TEDs may reduce shark bycatch in this fishery.

  7. Sustainability of capture of fish bycatch in the prawn trawling in northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Carlos Antonio Beserra da Silva Junior

    Full Text Available The prawn fishery produces more discards than any other type of catch and captures a large quantity of immature individuals. This research aimed to assess the sustainability of capture of fish bycatch in prawn trawling. Each species was assessed according to two groups of criteria: (1 their relative vulnerability to capture by trawl and mortality due to this fishery (2 recovery capacity of the specie after a possible collapse of the population. Within each group, each species was ranked (1-3, being 1 the highest value, meaning the species is highly susceptible to capture or has a low resilience. A total of 8,894 individuals were caught, belonging to 28 families. The species with capture least sustainable were Stellifer rastrifer and Isopisthus parvipinnis. These latter species are highly susceptible since they are either benthic or demersal, and their diet may include benthic organism. Chirocentrodon bleekerianus and Anchoa tricolor were the most likely fishes to be sustainable since they are pelagic, they are least susceptible to capture by trawls, and also have a greater capacity to recover, as most individuals have bred before capture. Due to the fishery's multi-specific nature, it is difficult to implement mitigation measures for specific species. Thus, the creation of fishing exclusion zones should be considered as the most appropriate management measure.

  8. The footprint of bottom trawling in European waters: distribution, intensity, and seabed integrity

    DEFF Research Database (Denmark)

    Eigaard, Ole Ritzau; Bastardie, Francois; Hinzen, N.T.

    2017-01-01

    for 2010-2012 at a grid cell resolution of 1 x 1 min longitude and latitude. Trawling intensity profiles with seabed impact at the surface and subsurface level are presented for 14 management areas in the North-east Atlantic, Baltic Sea and Mediterranean Sea. The footprint of the management areas ranged...... between 53-99% and 6-94% for the depth zone from 0 to 200 m (Shallow) and from 201 to 1000 m (Deep), respectively. The footprint was estimated as the total area of all grid cells that were trawled fully or partially. Excluding the untrawled proportions reduced the footprint estimates to 28-85% and 2......-77%. Largest footprints per unit landings were observed off Portugal and in the Mediterranean Sea. Mean trawling intensity ranged between 0.5 and 8.5 times per year, but was less in the Deep zone with a maximum intensity of 6.4. Highest intensities were recorded in the Skagerrak-Kattegat, Iberian Portuguese...

  9. Behavioral flexibility of the trawling long-footed bat, Macrophyllum macrophyllum (Phyllostomidae

    Directory of Open Access Journals (Sweden)

    Moritz eWeinbeer

    2013-11-01

    Full Text Available We assessed the behavioral flexibility of the trawling long-legged bat, Macrophyllum macrophyllum (Phyllostomidae in flight cage experiments by exposing it to prey suspended from nylon threads in the air and to food placed onto the water surface at varying distances to clutter-producing background (water plants. The bat revealed flexibility in foraging mode and caught prey in the air (aerial hawking and from the water surface (trawling. M. macrophyllum was constrained in finding food very near to and within clutter. As echolocation was the prime sensory mode used by M. macrophyllum for detection and localization of food, the bat might have been unable to perceive sufficient information from prey near clutter as background echoes from the water plant increasingly overlapped with echoes from food. The importance of echolocation for foraging is reflected in a stereotypic call pattern of M. macrophyllum that resembles other aerial insectivorous and trawling bats with a pronounced terminal phase (buzz prior to capture attempts. Our findings contrast studies of other phyllostomid bats that glean prey very near or from vegetation, often using additional sensory cues, such as prey-produced noise, to find food and that lack a terminal phase in echolocation behavior. In M. macrophyllum, acoustic characteristics of its foraging habitat have shaped its sonar system more than phylogeny.

  10. Quantifying the Escape Mortality of Trawl Caught Antarctic Krill (Euphausia superba)

    Science.gov (United States)

    Krafft, Bjørn A.; Krag, Ludvig A.; Engås, Arill; Nordrum, Sigve; Bruheim, Inge; Herrmann, Bent

    2016-01-01

    Antarctic krill (Euphausia superba) is an abundant fishery resource, the harvest levels of which are expected to increase. However, many of the length classes of krill can escape through commonly used commercial trawl mesh sizes. A vital component of the overall management of a fishery is to estimate the total fishing mortality and quantify the mortality rate of individuals that escape from fishing gear. The methods for determining fishing mortality in krill are still poorly developed. We used a covered codend sampling technique followed by onboard observations made in holding tanks to monitor mortality rates of escaped krill. Haul duration, hydrological conditions, maximum fishing depth and catch composition all had no significant effect on mortality of krill escaping 16 mm mesh size nets, nor was any further mortality associated with the holding tank conditions. A non- parametric Kaplan-Meier analysis was used to model the relationship between mortality rates of escapees and time. There was a weak tendency, though not significant, for smaller individuals to suffer higher mortality than larger individuals. The mortality of krill escaping the trawl nets in our study was 4.4 ± 4.4%, suggesting that krill are fairly tolerant of the capture-and-escape process in trawls. PMID:27622510

  11. Ecology of Juvenile Salmon in Shallow Tidal Freshwater Habitats of the Lower Columbia River, 2007–2010

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Gary E.; Storch, Adam; Skalski, J. R.; Bryson, Amanda J.; Mallette, Christine; Borde, Amy B.; Van Dyke, E.; Sobocinski, Kathryn L.; Sather, Nichole K.; Teel, David; Dawley, Earl M.; Ploskey, Gene R.; Jones, Tucker A.; Zimmerman, Shon A.; Kuligowski, D. R.

    2011-03-01

    The TFM study was designed to investigate the ecology and early life history of juvenile salmonids within shallow (<5 m) tidal freshwater habitats of the LCRE. We started collecting field data in June 2007. Since then, monthly sampling has occurred in the vicinity of the Sandy River delta (rkm 192–208) and at other sites and times in lower river reaches of tidal freshwater (rkm 110 to 141). This report provides a comprehensive synthesis of data covering the field period from June 2007 through April 2010.

  12. Comparative Analysis of the Shared Sex-Determination Region (SDR) among Salmonid Fishes.

    Science.gov (United States)

    Faber-Hammond, Joshua J; Phillips, Ruth B; Brown, Kim H

    2015-06-25

    Salmonids present an excellent model for studying evolution of young sex-chromosomes. Within the genus, Oncorhynchus, at least six independent sex-chromosome pairs have evolved, many unique to individual species. This variation results from the movement of the sex-determining gene, sdY, throughout the salmonid genome. While sdY is known to define sexual differentiation in salmonids, the mechanism of its movement throughout the genome has remained elusive due to high frequencies of repetitive elements, rDNA sequences, and transposons surrounding the sex-determining regions (SDR). Despite these difficulties, bacterial artificial chromosome (BAC) library clones from both rainbow trout and Atlantic salmon containing the sdY region have been reported. Here, we report the sequences for these BACs as well as the extended sequence for the known SDR in Chinook gained through genome walking methods. Comparative analysis allowed us to study the overlapping SDRs from three unique salmonid Y chromosomes to define the specific content, size, and variation present between the species. We found approximately 4.1 kb of orthologous sequence common to all three species, which contains the genetic content necessary for masculinization. The regions contain transposable elements that may be responsible for the translocations of the SDR throughout salmonid genomes and we examine potential mechanistic roles of each one.

  13. Extending juvenility in grasses

    Energy Technology Data Exchange (ETDEWEB)

    Kaeppler, Shawn; de Leon Gatti, Natalia; Foerster, Jillian

    2017-04-11

    The present invention relates to compositions and methods for modulating the juvenile to adult developmental growth transition in plants, such as grasses (e.g. maize). In particular, the invention provides methods for enhancing agronomic properties in plants by modulating expression of GRMZM2G362718, GRMZM2G096016, or homologs thereof. Modulation of expression of one or more additional genes which affect juvenile to adult developmental growth transition such as Glossy15 or Cg1, in conjunction with such modulation of expression is also contemplated. Nucleic acid constructs for down-regulation of GRMZM2G362718 and/or GRMZM2G096016 are also contemplated, as are transgenic plants and products produced there from, that demonstrate altered, such as extended juvenile growth, and display associated phenotypes such as enhanced yield, improved digestibility, and increased disease resistance. Plants described herein may be used, for example, as improved forage or feed crops or in biofuel production.

  14. DERMATOMIOSITIS JUVENIL Y EMBARAZO

    OpenAIRE

    Evans M,Gregorio; Poulsen R,Ronald; Blanco R,Romiely; Luna V,Viviana

    2002-01-01

    La dermatomiositis juvenil es un desorden inflamatorio crónico multisistémico del tejido conectivo. Tiene una incidencia de 2-3/100.000/año. Con la disminución en la mortalidad experimentada en los últimos decenios, la atención está cifrada en la morbilidad a largo plazo y en las alteraciones funcionales. Con un tratamiento agresivo los niños con dermatomiositis juvenil generalmente tienen un futuro promisorio, sin incapacidad o con incapacidad mínima. La mortalidad actualmente se estima cerc...

  15. Juvenile idiopatiske inflammatoriske myopatier

    Directory of Open Access Journals (Sweden)

    Helga Sanner

    2009-10-01

    Full Text Available Juvenile idiopathic inflammatory myopathies (JIIM is a group of rare autoimmune systemic diseases in children and adolescents, characterized by chronic skeletal muscle inflammation. Unlike in adults, dermatomyositis (JDM is by far the most common of the idiopathic inflammatory myopathies in children and adolescents. The hallmark of JDM is calcinosis, lipodystrophy and vasculitis, findings that differs the juvenile form of dermatomyosits from the adult form. JDM is still diagnosed and classified by Bohan and Peter’s criteria from 1975. There are limited data on long time outcome of this disease

  16. Trapping and Transportation of Adult and Juvenile Salmon in the Lower Umatilla River in Northeast Oregon, 1995-1996 : Umatilla River Basin Trap and Haul Program : Annual Progress Report, October 1995-September 1996.

    Energy Technology Data Exchange (ETDEWEB)

    Zimmerman, Brian C.; Duke, Bill B.

    1996-09-01

    Threemile Falls Dam (Threemile Dam), located near the town of Umatilla, is the major collection and counting point for adult salmonids returning to the Umatilla River. Returning salmon and steelhead were collected at Threemile Dam from September 5, 1995 to July 1, 1996. A total of 2,081 summer steelhead (Oncorhynchus mykiss); 603 adult, 288 jack, and 338 subjack fall chinook (O. tshawytscha); 946 adult and 53 jack coho (O. kisutch); and 2,152 adult and 121 jack spring chinook (O. tshawytscha) were collected. All fish were trapped at the east bank facility. The Westland Canal juvenile facility (Westland), located near the town of Echo at rivermile (RM) 27, is the major collection point for outmigrating juvenile salmonids and steelhead kelts. The Threemile Dam west bank juvenile bypass was operated from September 8 to October 13, 1995 and from March 18 to June 30, 1996. The juvenile trap was operated from July 1 to July 11. Daily operations at the facility were conducted by the ODFW Fish Passage Research project to monitor juvenile outmigration.

  17. Juvenile Battens Disease.

    Science.gov (United States)

    Gayton, Romayne

    1987-01-01

    Ten children diagnosed with juvenile Battens disease were tested over a three-year period in general intelligence, memory, listening and speech, motor skills, and general learning. Results showed that the patients followed a predetermined pattern but that the time span for development of memory, communication, and behavior problems varied greatly.…

  18. Juvenile Victimization and Delinquency.

    Science.gov (United States)

    Esbensen, Finn-Aage; Huizinga, David

    1991-01-01

    Demographic characteristics of juvenile victims of crime and a potential relationship between victimization and self-reported delinquency are examined for 877 adolescents from a large midwestern city. Lifetime victimization rates (LVRs) are higher for those involved in delinquency, and LVRs rise with age and higher levels of delinquent behavior.…

  19. Juvenile Battens Disease.

    Science.gov (United States)

    Gayton, Romayne

    1987-01-01

    Ten children diagnosed with juvenile Battens disease were tested over a three-year period in general intelligence, memory, listening and speech, motor skills, and general learning. Results showed that the patients followed a predetermined pattern but that the time span for development of memory, communication, and behavior problems varied greatly.…

  20. Juvenile idiopathic arthritis

    NARCIS (Netherlands)

    Prakken, Berent; Albani, Salvatore; Martini, Alberto

    2011-01-01

    Juvenile idiopathic arthritis is a heterogeneous group of diseases characterised by arthritis of unknown origin with onset before age of 16 years. Pivotal studies in the past 5 years have led to substantial progress in various areas, ranging from disease classification to new treatments. Gene expres

  1. Bottom trawling and oxygen minimum zone influences on continental slope benthic community structure off Vancouver Island (NE Pacific)

    Science.gov (United States)

    De Leo, Fabio C.; Gauthier, Maéva; Nephin, Jessica; Mihály, Steven; Juniper, S. Kim

    2017-03-01

    Understanding responses of benthic ecosystems to cumulative impacts of natural stressors, long-term ocean change and increasing resource exploitation is an emerging area of interest for marine ecologists and environmental managers. Few, if any, studies have quantitatively addressed cumulative effects in the deep sea. We report here on a study from the continental slope off Vancouver Island (Canada) in the northeast Pacific Ocean, where the Oxygen Minimum Zone impinges on seabed habitats that are subjected to widespread bottom trawling, primarily by the fishery for thornyhead (Sebastolobus ssp.). We examined how the benthic megafauna in this area was influenced by varying levels of dissolved oxygen and trawling activity, along a depth gradient that was also likely to shape community composition. Continuous video and sonar records from two ROV surveys (50 linear km total; depth range 300-1400 m) respectively provided data on faunal attributes (composition, abundance and diversity) and the frequency of trawl door marks on the seabed. Faunal and trawl data were compiled in a geo-referenced database along with corresponding dissolved oxygen data, and pooled into 500 m segments for statistical analysis. Trawl mark occurrence peaked between 500 and 1100 m, corresponding to areas of slope subjected to hypoxia (<1.4 ml l-1) and severe hypoxia (<0.5 ml l-1). A combined total of 266,251 megafauna organisms from 87 taxa were enumerated in the two transects. Significant megafaunal assemblages according to depth, trawling intensity and bottom water dissolved oxygen concentration were identified by PERMANOVA analyses, with characterizing taxa identified for all three factors. Depth, dissolved oxygen and trawl mark density accounted for 21% to 52% of the variability in benthic community structure according to multiple regression (DISTLM) models. Species richness was highest at intermediate depths and in areas subject to intermediate levels of trawling, and higher under hypoxia

  2. Quality and Behavior of Juvenile Salmonids in the Columbia River Estuary and Nearshore Ocean and Effects of the Ocean Environment on the Survival of Columbia River Juvenile Salmonids, 1989-1994 Technical Report.

    Energy Technology Data Exchange (ETDEWEB)

    Francis, R.C.; Schiewe, Michael H.; Fisher, J.P.

    1989-05-01

    In response to this limited understanding of the factors responsible for the continuing decline of spring chinook salmon in the Columbia River, this research plan was developed. The overall goal of the proposed research is to investigate and identify relationships among smolt quality (measured in the hatchery and after recovery in the estuary and nearshore ocean), environmental conditions in the estuary and nearshore ocean during smolt migration, and long-term survival (as measured by adult returns to the hatchery of origin and contributions to the recreational, commercial, and tribal fisheries). 16 refs., 15 figs., 3 tabs.

  3. AFSC/RACE/EcoFOCI - Trawl catch data collected in support of FOCI assessment surveys and ecosystem observations in the Bering Sea and the Gulf of Alaska 1993 to Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The trawl database contains multiple tables of data. The ‘haul’ table contains the location, date, time and depth of the trawl haul. The ‘catch’ table contains the...

  4. AFSC/ABL: Gulf of Alaska Diel Trawl Survey, 2005-2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Diel epipelagic sampling for juvenile Pacific salmon (Oncorhynchus spp.), rockfish (Sebastes spp.), sablefish (Anoplopoma fimbria), and associated species was...

  5. When does fishing lead to more fish? Community consequences of bottom trawl fisheries in demersal food webs.

    Science.gov (United States)

    van Denderen, P Daniel; van Kooten, Tobias; Rijnsdorp, Adriaan D

    2013-10-22

    Bottom trawls are a globally used fishing gear that physically disturb the seabed and kill non-target organisms, including those that are food for the targeted fish species. There are indications that ensuing changes to the benthic invertebrate community may increase the availability of food and promote growth and even fisheries yield of target fish species. If and how this occurs is the subject of ongoing debate, with evidence both in favour and against. We model the effects of trawling on a simple ecosystem of benthivorous fish and two food populations (benthos), susceptible and resistant to trawling. We show that the ecosystem response to trawling depends on whether the abundance of benthos is top-down or bottom-up controlled. Fishing may result in higher fish abundance, higher (maximum sustainable) yield and increased persistence of fish when the benthos which is the best-quality fish food is also more resistant to trawling. These positive effects occur in bottom-up controlled systems and systems with limited impact of fish feeding on benthos, resembling bottom-up control. Fishing leads to lower yields and fish persistence in all configurations where susceptible benthos are more profitable prey. Our results highlight the importance of mechanistic ecosystem knowledge as a requirement for successful management.

  6. Prenatal stress from trawl capture affects mothers and neonates: a case study using the southern fiddler ray (Trygonorrhina dumerilii)

    Science.gov (United States)

    Guida, L.; Awruch, C.; Walker, T. I.; Reina, R. D.

    2017-04-01

    Assessing fishing effects on chondrichthyan populations has predominantly focused on quantifying mortality rates. Consequently, sub-lethal effects of capture stress on the reproductive capacity of chondrichthyans are largely unknown. We investigated the reproductive consequences of capture on pregnant southern fiddler rays (Trygonorrhina dumerilii) collected from Swan Bay, Australia, in response to laboratory-simulated trawl capture (8 h) followed immediately by air exposure (30 min). Immediately prior to, and for up to 28 days post trawling, all females were measured for body mass (BM), sex steroid concentrations (17-β estradiol, progesterone, testosterone) and granulocyte to lymphocyte (G:L) ratio. At parturition, neonates were measured for total length (TL), BM and G:L ratio. Trawling reduced maternal BM and elevated the G:L ratio for up to 28 days. Trawling did not significantly affect any sex steroid concentrations relative to controls. Neonates from trawled mothers were significantly lower in BM and TL than control animals, and had an elevated G:L ratio. Our results show that capture of pregnant T. dumerilii can influence their reproductive potential and affect the fitness of neonates. We suggest other viviparous species are likely to be similarly affected. Sub-lethal effects of capture, particularly on reproduction, require further study to improve fisheries management and conservation of chondrichthyans.

  7. Improving the selectivity of beam trawls in The Netherlands: the effect of large mesh top panels on the catch rates of sole, plaice, cod and whiting

    NARCIS (Netherlands)

    Marlen, van B.

    2003-01-01

    This paper presents the results of experiments aimed to improve the selectivity of beam trawls in the North Sea for roundfish whilst minimizing losses on target flatfish. Large-meshed top panels were designed for the tickler chain type of beam trawls used in this fishery. The design process involved

  8. Bell-shaped size selection in a bottom trawl: A case study for Nephrops directed fishery with reduced catches of cod

    DEFF Research Database (Denmark)

    Lövgren, Johan; Herrmann, Bent; Feekings, Jordan P.

    2016-01-01

    and size selectivity have motivated the development of selective systems in trawl fisheries that utilize more than one selective device simultaneously. An example can be found in the Swedish demersal trawl fishery targeting Norway lobster (Nephrops norvegicus), which simultaneously aims at avoiding catches...

  9. Improving the selectivity of beam trawls in The Netherlands: the effect of large mesh top panels on the catch rates of sole, plaice, cod and whiting

    NARCIS (Netherlands)

    Marlen, van B.

    2003-01-01

    This paper presents the results of experiments aimed to improve the selectivity of beam trawls in the North Sea for roundfish whilst minimizing losses on target flatfish. Large-meshed top panels were designed for the tickler chain type of beam trawls used in this fishery. The design process involved

  10. Mapping spatial variation in demersal fish species diversity and composition in the North Sea: accounting for species- and size-related catchability in survey trawls

    NARCIS (Netherlands)

    Fraser, H.M.; Greenstreet, S.P.R.; Fryer, R.J.; Piet, G.J.

    2008-01-01

    The paper maps spatial patterns of groundfish species diversity. It considers how the catchability of different fish species in two different types of bottom trawls, the IBTS GOV and the 8-m beam trawl, influences the estimates of species diversity. Maps of groundfish species diversity derived from

  11. A comparison between benthic gillnet and bottom trawl for assessing fish assemblages in a shallow eutrophic lake near the Changjiang River estuary

    Science.gov (United States)

    Li, Yalei; Liu, Qigen; Chen, Liping; Zhao, Liangjie; Wu, Hao; Chen, Liqiao; Hu, Zhongjun

    2017-06-01

    Two fishing methods including gillnetting and trawling to estimate attributes of fish assemblage were compared in Dianshan Lake from August 2009 to July 2010. Species composition differed significantly between the gears, with four significant contributors in gillnet catches and one in trawl catches. Trawling collected more proportions of benthic species by number and biomass than gillnetting. Size distribution was significantly influenced by fishing technique; gillnetting captured relatively less small-sized fishes and trawling captured less large-sized individuals. Trawling produced species richness closer to the one expected than gillnetting. On the whole, trawl catch was a quadratic polynomial function of gillnet catch and a significantly negative correlation was found between them, both of which varied as different polynomial functions of temperature. However, trawl and gillnet catches were significantly correlated only in one of five month groups. It is concluded that single-gear-based surveys can be misleading in assessments of attributes of fish assemblages, bottom trawling is a more effective gear for assessing fish diversity than benthic gillnetting, and using gillnet catches as an indicator of fish density depends on fishing season in the lake.

  12. Double-crested Cormorant Management Plan to Reduce Predation of Juvenile Salmonids in the Columbia River Estuary

    Science.gov (United States)

    2015-01-01

    AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) U.S. Army Corps of Engineers...Fisheries Service of the National Oceanic and Atmospheric Administration (NOAA Fisheries) for the operation of the hydropower dams that make up the Federal...through t he Columbia River Basin to the Pacific Ocean, in t he context of other identified point-sources of mortality such as hydropower dams, the

  13. Evaluation of Juvenile Salmonid Outmigration and Survival in the Lower Umatilla River Basin, Annual Report 1998-1999.

    Energy Technology Data Exchange (ETDEWEB)

    Ehlers, Danette L.; Knapp, Suzanne M.; Jewett, Shannon M.

    2001-05-01

    Large runs of salmon (Oncorhynchus spp.) and steelhead (O. mykiss) once supported productive Tribal and sport fisheries in the Umatilla River. By the 1920s, unscreened irrigation diversions, reduced in-stream flows, poor passage conditions, and habitat degradation had extirpated the salmon run and drastically reduced the summer steelhead run (CTUIR and ODFW 1989). Reintroduction of chinook salmon (O. tshawytscha) and coho salmon (O. kisutch) and enhancement of summer steelhead populations in the Umatilla River was initiated in the early and mid-1980s (CTUIR and ODFW 1989). Measures to rehabilitate the fishery and improve flows in the Umatilla River are addressed in the original Northwest Power Planning Council's Columbia River Basin Fish and Wildlife Program (NPPC 1987). These include habitat enhancement, hatchery production, holding and acclimation facilities, flow enhancement, passage improvement, and natural production enhancement. Detailed scope and nature of the habitat, flow, passage, and natural production projects are in the Umatilla River basin fisheries restoration plans (CTUIR 1984; Boyce 1986). The Umatilla Hatchery Master Plan (CTUIR and ODFW 1990) provides the framework for hatchery production and evaluation activities. Many agencies cooperate, coordinate, and exchange information in the Umatilla basin to ensure successful implementation of rehabilitation projects, including the Oregon Department of Fish and Wildlife (ODFW), the U.S. Bureau of Reclamation (USBR), the Bonneville Power Administration (BPA), National Marine Fisheries Service (NMFS), Oregon Water Resources Department (OWRD), the Confederated Tribes of the Umatilla Indian Reservation (CTUIR), and local irrigation districts (West Extension, Hermiston, and Stanfield-Westland). The Umatilla River Operations Group and the Umatilla Management, Monitoring and Evaluation Oversight Committee coordinate river and fisheries management and research in the Umatilla River basin.

  14. MONITORING CULVERT PASSAGE OF JUVENILE SALMONIDS WITH PIT TAGS AND STATIONARY AND PORTABLE PIT-TAG READERS

    Science.gov (United States)

    Federal land management agencies in the PNW face increasing pressure to replace culverts that do not pass all life history stages of anadromous salmon and trout. Prioritization of culverts for replacement is often based on the physical parameters of culverts, and not on how fish...

  15. Survival estimates - Survival estimates for the passage of juvenile salmonids through Snake and Columbia River dams and reservoirs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This BPA-funded study provides estimates of smolt survival and travel time through individual reaches and reaches combined in the Snake and Columbia Rivers...

  16. Assessment of resource selection models to predict occurrence of five juvenile flatfish species (Pleuronectidae) over the continental shelf in the western Gulf of Alaska

    Science.gov (United States)

    Wilson, Matthew T.; Mier, Kathryn L.; Cooper, Dan W.

    2016-05-01

    According to the nursery size hypothesis, flatfish recruitment is constrained by nursery area. Thus, if resource selection models can be shown to accurately predict the location and geographic extent of flatfish nursery areas, they will become important tools in the management and study of flatfish population dynamics. We demonstrate that some resource selection models derived previously to predict the presence and absence of juvenile flatfishes near shore were applicable to the broader continental shelf. For other age-species groups, derivation of new models for the continental shelf was necessary. Our study was conducted in the western Gulf of Alaska (GoA) during October 2011 on four groups of age-0 juvenile flatfishes: Pacific halibut (Hippoglossus stenolepis), arrowtooth flounder (Atheresthes stomias), northern rock sole (Lepidopsetta polyxystra), and flathead sole (Hippoglossoides elassodon); and three groups of age-1 juvenile flatfishes: northern rock sole, flathead sole, and yellowfin sole (Limanda aspera). Sampling occurred at 33 sites across the continental shelf. Fish were collected using a 3-m beam trawl, and a midwater trawl. Environmental data were collected on sediment composition and water temperature and depth. Many of the age-species groups co-occurred in the Shumagin and Barnabus sea valleys; however, age-0 arrowtooth flounder occurred at more locations than other juveniles, perhaps due to a relatively broad tolerance of environmental conditions and to the utilization of midwater habitat. Thus, the large nursery area of arrowtooth flounder may be one reason why they are currently the most abundant GoA flatfish. In fact, among all species, mean recruitment at age 3 increased with the percent occurrence of age-0 juveniles at the 33 sites, a proxy for relative nursery area, in accordance with the nursery size hypothesis, suggesting that mean recruitment among GoA flatfishes is structured by nursery size.

  17. Influence of dreissenid mussels on catchability of benthic fishes in bottom trawls

    Science.gov (United States)

    Kocovsky, Patrick M.; Stapanian, Martin A.

    2011-01-01

    Inferring trends in true abundance of fish populations from catch per unit effort data requires either the knowledge of capture probability or the assumption that it is constant, both of which are unlikely contingencies. We developed and validated an index of catchability (a proxy measure for capture probability) from a long-term data set describing nearshore waters of western Lake Erie, and we used the index to test the hypothesis that catchability of four abundant benthic species captured in bottom trawls changed after the invasion of dreissenid mussels. We estimated daytime and nighttime catchability for 1972–1990 (predreissenid period) and 1991–2009 (dreissenid period); we then tested for differences between nighttime and daytime catchability in the predreissenid and dreissenid periods and the nighttime–daytime differential in catchability during the dreissenid period. We also tested relationships between Secchi depth and the catchability index via linear regression. Catchability indices for white perch Morone americana, yellow perch Perca flavescens, and trout-perch Percopsis omiscomaycus did not differ between daytime and nighttime during the predreissenid period. After establishment of dreissenids, all three of these species had lower daytime catchability than nighttime catchability and had positive nighttime–daytime differentials, indicating a shift toward higher nighttime catchability relative to daytime catchability. Changes in catchability indices for freshwater drum Aplodinotus grunniens were opposite the changes observed for the other three species, possibly because the freshwater drum is the only species that actively feeds on dreissenids. Catchability indices were negatively related to water clarity (Secchi depth) for three of the species. Our results are consistent with the hypothesis that catchability of the four most common benthic fish species captured in bottom trawls within nearshore waters of western Lake Erie changed after the

  18. Relationships between water mass characteristics and estimates of fish population abundance from trawl surveys.

    Science.gov (United States)

    Smith, S J; Perry, R I; Fanning, L P

    1991-01-01

    The Canadian Department of Fisheries and Oceans conducts annual bottom trawl surveys to monitor changes in the abundance of the major commercially important groundfish populations. Some of these surveys have been in operation for almost 20 yr. The estimates from these surveys often indicate rapid changes in abundance over time beyond that expected from the population dynamics of the fish. Much of this interannual change has been interpreted as variation, the magnitude of which has often made it difficult to measure anything but the most severe effects of fishing, pollution or any other intervention on the population. Recent studies have shown that some of this variation may be attributed to changes in catchability of fish due to the effects of environmental variables on fish distribution. Annual changes in abundance as estimated from such field surveys may be confounded by changes in catchability due to annual changes in environmental conditions. In this study, trawl catches of age 4 Atlantic cod (Gadus morhua) from surveys conducted during March 1979-1988 were compared with concurrent measurements of bottom salinity, temperature and depth. Large catches of age 4 cod are more likely to occur in water characterized as the intermediate cold layer defined by salinities of 32-33.5 and temperatures<5°C. This relationship also appears to be modified by depth. We further show that internnual changes in the estimated abundance from the surveys were, in a number of cases, coincident with changes in the proportion of the bottom water composed of the intermediate cold water layer. The implications that these patterns may have on interpreting trends in the estimates of abundance from trawl surveys are discussed.

  19. Challenges in licensing the industrial double-rig trawl fisheries in Brazil

    Directory of Open Access Journals (Sweden)

    Paulo Ricardo-Pezzuto

    2015-07-01

    Full Text Available Bottom trawling is important in Brazilian fisheries and is currently highly multi-specific due to the overexploitation of the original targets; unselective fishing method; very large permitted fishing area and the country's high marine biodiversity. Fishing licensing in Brazil was modified in 2012 and is now based in five criteria: target species; "expected by-catch"; "incidental catches"; fishing method and area of operation. Licenses of trawling fleets exhibit, therefore, dozens of species catchable under the first three criteria. In this paper, we analyze industrial double-rig trawling fleets targeting shrimps and demersal fishes, in order to verify in what extent the new system adhere to the current fishing reality, giving new information to improve the current management regime. A total of 4,194 trips from 191 vessels were studied between 2008 and 2010 in southern Brazil. In spite of depending economically on their targets, the fleets are formally authorized to catch a high percentage of species in common (41 to 71%, and the actual landings revealed an even greater overlapping among them (71 to 82%. Vessels licensed to catch demersal fishes obtained nearly 50% of their revenue from items not included in their licenses. It was concluded that the current system encourages excessive effort concentrations over fishing resources, as they can be legally caught by most vessels irrespective of their licenses. It is suggested that licensing should move from a species-based to a spatial-based approach, by defining smaller management areas according to the respective species assemblages. Landing composition would be, therefore, mostly a biological and technological consequence, making management more reasonable and workable under a multi-specific and mega-diverse scenario.

  20. The vertical separation of fish in the aft end of a demersal trawl

    DEFF Research Database (Denmark)

    Krag, Ludvig Ahm; Holst, René; Madsen, Niels

    2009-01-01

    and to compare the performance of the two frames. The vertical distribution of cod in the aft end of the trawl was close to uniform, whereas haddock (Melanogrammus aeglefinus), whiting (Merlangius merlangus), plaice (Pleuronectes platessa), and lemon sole (Microstomus kitt) showed more uneven distributions....... The use of guiding bars in the separator frame significantly (p lemon sole in the upper compartment. The vertical separation of cod was density-dependent; high densities of fish resulted in a more uniform distribution of cod. The species separations found...

  1. Low Temperature-Dependent Salmonid Alphavirus Glycoprotein Processing and Recombinant Virus-Like Particle Formation

    NARCIS (Netherlands)

    Metz, S.W.H.; Feenstra, F.; Villoing, S.; Hulten, van M.C.; Lent, van J.W.M.; Koumans, J.; Vlak, J.M.; Pijlman, G.P.

    2011-01-01

    Pancreas disease (PD) and sleeping disease (SD) are important viral scourges in aquaculture of Atlantic salmon and rainbow trout. The etiological agent of PD and SD is salmonid alphavirus (SAV), an unusual member of the Togaviridae (genus Alphavirus). SAV replicates at lower temperatures in fish.

  2. Low Temperature-Dependent Salmonid Alphavirus Glycoprotein Processing and Recombinant Virus-Like Particle Formation

    NARCIS (Netherlands)

    Metz, S.W.H.; Feenstra, F.; Villoing, S.; Hulten, van M.C.; Lent, van J.W.M.; Koumans, J.; Vlak, J.M.; Pijlman, G.P.

    2011-01-01

    Pancreas disease (PD) and sleeping disease (SD) are important viral scourges in aquaculture of Atlantic salmon and rainbow trout. The etiological agent of PD and SD is salmonid alphavirus (SAV), an unusual member of the Togaviridae (genus Alphavirus). SAV replicates at lower temperatures in fish. Ou

  3. Invasion versus isolation: Trade-offs in managing native salmonids with barriers to upstream movement

    Science.gov (United States)

    Kurt D. Fausch; Bruce E. Rieman; Jason B. Dunham; Michael K. Young; Douglas P. Peterson

    2009-01-01

    Conservation biologists often face the trade-off that increasing connectivity in fragmented landscapes to reduce extinction risk of native species can foster invasion by non-native species that enter via the corridors created, which can then increase extinction risk. This dilemma is acute for stream fishes, especially native salmonids, because their populations are...

  4. Modes of salmonid MHC class I and II evolution differ from the primate paradigm

    NARCIS (Netherlands)

    Shum, B.P.; Guethlein, L.; Flodin, L.R.; Adkison, M.A.; Hedrick, R.P.; Nehring, R.B.; Stet, R.J.M.; Secombes, C.; Parham, P.

    2001-01-01

    Rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta) represent two salmonid genera separated for 15-20 million years. cDNA sequences were determined for the classical MHC class I heavy chain gene UBA and the MHC class II β-chain gene DAB from 15 rainbow and 10 brown trout. Both genes a

  5. Comparison of growth and metabolic regulation between wild, domesticated and transgenic salmonids.

    Science.gov (United States)

    To gain a better understanding of the aspects underlying normal and growth hormone enhanced growth in salmonids, quantitative expression analysis was performed for a number of genes related to muscle growth, metabolism, immunology and energy regulation. This analysis was performed in liver and musc...

  6. Osmoregulatory actions of the GH/IGF axis in non-salmonid teleosts

    Science.gov (United States)

    Mancera, J.M.; McCormick, S.D.

    1998-01-01

    Salmonid fishes provided the first findings on the influence of the growth hormone (GH)/insulin-like growth factor I (IGF-I) axis on osmoregulation in teleost fishes. Recent studies on non-salmonid species, however, indicate that this physiological action of the GH/IGF-I axis is not restricted to salmonids or anadromous fishes. GH-producing cells in the pituitary of fish acclimated to different salinities show different degrees of activation depending on the species studied. Plasma GH levels either increase or do not change after transfer of fish from freshwater to seawater. Treatment with GH or IGF-I increases salinity tolerance and/or increases gill Na+,K+-ATPase activity of killifish (Fundulus heteroclitus), tilapia (Oreochromis mossambicus and Oreochromis niloticus) and striped bass (Morone saxatilis). As in salmonids, a positive interaction between GH and cortisol for improving hypoosmoregulatory capacity has been described in tilapia (O. mossambicus). Research on the osmoregulatory role of the GH/IGF-I axis is derived from a small number of teleost species. The study of more species with different osmoregulary patterns will be necessary to fully clarify the osmoregulatory role of GH/IGF-I axis in fish. The available data does suggest, however, that the influence of the GH/IGF-I axis on osmoregulation may be a common feature of euryhalinity in teleosts. Copyright (C) 1998 Elsevier Science Inc.

  7. Salmonid alphavirus replication in mosquito cells: towards a novel vaccine production system

    NARCIS (Netherlands)

    Hikke, M.C.; Verest, M.; Vlak, J.M.; Pijlman, G.P.

    2014-01-01

    Salmonid alphavirus (SAV) causes pancreas disease and sleeping disease in Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) and confers a major burden to the aquaculture industry. A commercial inactivated whole virus vaccine propagated in a salmon cell line at low temperature pro

  8. Barriers, invasion, and conservation of native salmonids in coldwater streams [Box 18.2

    Science.gov (United States)

    Bruce Rieman; Michael Young; Kurt Fausch; Jason Dunham; Douglas Peterson

    2010-01-01

    Habitat loss and fragmentation are threats to persistence of many native fish populations. Invading nonnative species that may restrict or displace native species are also important. These two issues are particularly relevant for native salmonids that are often limited to remnant habitats in cold, headwater streams. On the surface, reversing threats to native fishes...

  9. Efficacy of benzocaine as an anesthetic for salmonid fishes

    Science.gov (United States)

    Gilderhus, P.A.

    1989-01-01

    Benzocaine was tested in the laboratory to determine the effective concentrations for anesthetizing juvenile chinook salmon Oncorhynchus tshawytscha an rainbow trout O. mykiss (formerly Salmo gairdneri ). Tests were conducted at three water temperatures, in waters ranging from very soft to very hard, and with groups of rainbow trout from 5 to 47 cm long and chinook salmon 20 cm long. Effective concentrations were defined as those that rendered the fish fully handleable in 3 min or less, allowed recovery of most fish within 10 min, and caused no mortality after 15-min exposures. Concentrations of 25-45 mg/L anesthetized both species over the entire range of conditions tested. Although efficacy was essentially unrelated to species or water quality, it was related to water temperature and size of fish; the concentrations of benzocaine required were highest at the lowest water temperature and for the largest fish.

  10. Impact of bottom trawling on deep-sea sediment properties along the flanks of a submarine canyon.

    Directory of Open Access Journals (Sweden)

    Jacobo Martín

    Full Text Available The offshore displacement of commercial bottom trawling has raised concerns about the impact of this destructive fishing practice on the deep seafloor, which is in general characterized by lower resilience than shallow water regions. This study focuses on the flanks of La Fonera (or Palamós submarine canyon in the Northwestern Mediterranean, where an intensive bottom trawl fishery has been active during several decades in the 400-800 m depth range. To explore the degree of alteration of surface sediments (0-50 cm depth caused by this industrial activity, fishing grounds and control (untrawled sites were sampled along the canyon flanks with an interface multicorer. Sediment cores were analyzed to obtain vertical profiles of sediment grain-size, dry bulk density, organic carbon content and concentration of the radionuclide 210Pb. At control sites, surface sediments presented sedimentological characteristics typical of slope depositional systems, including a topmost unit of unconsolidated and bioturbated material overlying sediments progressively compacted with depth, with consistently high 210Pb inventories and exponential decaying profiles of 210Pb concentrations. Sediment accumulation rates at these untrawled sites ranged from 0.3 to 1.0 cm y-1. Sediment properties at most trawled sites departed from control sites and the sampled cores were characterized by denser sediments with lower 210Pb surface concentrations and inventories that indicate widespread erosion of recent sediments caused by trawling gears. Other alterations of the physical sediment properties, including thorough mixing or grain-size sorting, as well as organic carbon impoverishment, were also visible at trawled sites. This work contributes to the growing realization of the capacity of bottom trawling to alter the physical properties of surface sediments and affect the seafloor integrity over large spatial scales of the deep-sea.

  11. Influence of intermittent stream connectivity on water quality and salmonid survivorship.

    Science.gov (United States)

    Hildebrand, J.; Woelfle-Erskine, C. A.; Larsen, L.

    2014-12-01

    Anthropogenic stress and climate change are causing an increasing number of California streams to become intermittent and are driving earlier and more severe summertime drying. The extent to which emerging water conservation alternatives impact flows or habitat quality (e.g. temperature, DO) for salmonids remains poorly understood. Here, we investigate the proximal drivers of salmonid mortality over a range of connectivity conditions during summertime intermittency in Salmon Creek watershed, Sonoma County, CA. Through extensive sampling in paired subwatersheds over a period of two years, we tested the hypothesis that accumulation of readily bioavailable DOC in poorly flushed pools drives DO decline associated with loss of salmonids. We then traced the origin and flow pathways of DOC throughout the watershed using Parallel Factor Analysis (PARAFAC). We obtained samples for DOC and stable isotope analyses at monthly intervals from 20 piezometers and surface water in the study reaches and from private wells and springs distributed throughout the watersheds. We also obtained in situ DO, conductivity and pH readings within stream study reaches. We determined DOC quality by SUVA (specific UV absorbance) and fluorescence index. We calculated stream metabolism rates using the single station method. In pools instrumented with DO sensors, we compared changing DOC quality during the summer months to changes in DO concentrations and stream metabolism. Our results show that the duration of complete disconnection of pools during the summer months and stream metabolic rates are positively correlated with salmonid mortality. Furthermore, our results indicate that salmonid mortality is greatest in disconnected pools with low DOC fluorescence indices and high SUVA values, indicative of terrestrially derived DOC and little or no groundwater inflow. Conversely low salmonid mortality was found in disconnected pools with high fluorescence index and low SUVA, indicative of microbially

  12. Late Onset Juvenile Xanthogranuloma

    Directory of Open Access Journals (Sweden)

    Punithwavathy K

    1999-01-01

    Full Text Available A 19 year old female was seen with multiple skin coloured and hyperpigmented macules, discrete as well as grouped papules and nodules of varying sizes distributed over the face, neck, extensor and flexor aspects of both upper and lower extremities including joints. The trunk was spared. Some of the lesions showed features of spontaneous regression. Investigations confirmed the diagnosis of juvenile xanthogranuloma. Lesions regressed satisfactorily with liquid nitrogen cryotherapy.

  13. Juvenile Incarceration and Health

    OpenAIRE

    Barnert, ES; R Perry; Morris, RE

    2015-01-01

    © 2015. Addressing the health status and needs of incarcerated youth represents an issue at the nexus of juvenile justice reform and health care reform. Incarcerated youth face disproportionately higher morbidity and higher mortality compared to the general adolescent population. Dental health, reproductive health, and mental health needs are particularly high, likely as a result of lower access to care, engagement in high-risk behaviors, and underlying health disparities. Violence exposure a...

  14. Juvenile Ultracool Dwarfs

    CERN Document Server

    Rice, Emily L; Cruz, Kelle; Barman, Travis; Looper, Dagny; Malo, Lison; Mamajek, Eric E; Metchev, Stanimir; Shkolnik, Evgenya L

    2011-01-01

    Juvenile ultracool dwarfs are late spectral type objects (later than ~M6) with ages between 10 Myr and several 100 Myr. Their age-related properties lie intermediate between very low mass objects in nearby star-forming regions (ages 1-5 Myr) and field stars and brown dwarfs that are members of the disk population (ages 1-5 Gyr). Kinematic associations of nearby young stars with ages from ~10-100 Myr provide sources for juvenile ultracool dwarfs. The lowest mass confirmed members of these groups are late-M dwarfs. Several apparently young L dwarfs and a few T dwarfs are known, but they have not been kinematically associated with any groups. Normalizing the field IMF to the high mass population of these groups suggests that more low mass (mainly late-M and possibly L dwarf) members have yet to be found. The lowest mass members of these groups, along with low mass companions to known young stars, provide benchmark objects with which spectroscopic age indicators for juvenile ultracool dwarfs can be calibrated and...

  15. APPLICATION OF SALMONIDS (SALMONIDAE N THE BIOMONITORING OF AQUATIC ENVIRONMENT (REVIEW

    Directory of Open Access Journals (Sweden)

    D. Yanovych

    2016-03-01

    Full Text Available Purpose. Due to the pollution of fisheries water bodies by industrial and agricultural waste waters, as well as by xenobiotics coming from other sources, taking into account a pridictable increase in the amounts of such effluents in the short and long terms, the problems related to the study of the effects of the pollutants of different nature and origin on aquatic organisms, especially fish, as well as a prediction of possible adverse consequences on aquatic ecosystems, becomes particularly important. The aim of our work was an analysis and synthesis of existing literature data concerning the indication in the biomonitoring of aquatic environments based on biological markers of salmonids as highly sensitive objects of fish fauna to external factors. Findings. The review summarizes and systematizes the data concerning the use of salmonids in biomonitoring studies. Furthermore, we highlighted and characterized the specificity of bioindication parameters of the aquatic environment state, such as the biochemical, genetic, physiological, morphological, histopathological, behavioral and population markers and noted the effects of hydroecosystem ecotoxication on different levels of biological organization (cell, individual, population, fish community. We also described the possibility of biological monitoring based on saprobic indexes identified for indicator species belonging to salmonids. Originality. In the article describes the structure, pros and cons of the use of specific biomarkers of individual salmonid fish and their populations for assessing the ecological status of aquatic environments. Practical value. The data given in the article can be used to improve the system of the ecological monitoring of aquatic environments by extending the range of indicator indices with organism and population biomarkers of highly sensitive salmonid species.

  16. Genetics Home Reference: juvenile idiopathic arthritis

    Science.gov (United States)

    ... Home Health Conditions juvenile idiopathic arthritis juvenile idiopathic arthritis Printable PDF Open All Close All Enable Javascript ... view the expand/collapse boxes. Description Juvenile idiopathic arthritis refers to a group of conditions involving joint ...

  17. Genetics Home Reference: juvenile primary osteoporosis

    Science.gov (United States)

    ... Home Health Conditions juvenile primary osteoporosis juvenile primary osteoporosis Enable Javascript to view the expand/collapse boxes. ... PDF Open All Close All Description Juvenile primary osteoporosis is a skeletal disorder characterized by thinning of ...

  18. Genetics Home Reference: juvenile myoclonic epilepsy

    Science.gov (United States)

    ... Home Health Conditions juvenile myoclonic epilepsy juvenile myoclonic epilepsy Enable Javascript to view the expand/collapse boxes. ... PDF Open All Close All Description Juvenile myoclonic epilepsy is a condition characterized by recurrent seizures (epilepsy). ...

  19. Otter trawls in Greece: Landing profiles and potential mιtiers

    Directory of Open Access Journals (Sweden)

    S. KATSANEVAKIS

    2012-12-01

    Full Text Available A fleet of 326 bottom trawlers operate in Greek Seas and their landings represent approximately 30% of the total fish production in Greece. In this study, otter trawl landings data were analyzed in order to identify potential métiers. Landings data between 2002 and 2006 were used, collected from 42 ports in the Aegean and East Ionian Sea. A three-step procedure was applied to identify potential métiers: the first step involved a factorial analysis of the log-transformed landings profiles, the second step a classification of the factorial coordinates, and the third step a further aggregation of clusters based on expert knowledge. In all, six potential métiers were identified in the Aegean Sea, and five in the Ionian Sea. The most important target species were European hake (Merluccius merluccius, deepwater pink shrimp (Parapenaeus longirostris, red mullet (Mullus barbatus, caramote prawn (Melicertus kerathurus, picarel (Spicara smaris, cephalopods, bogue (Boops boops, anglers (Lophiusspp., and Norway lobster (Nephrops norvegicus. Otter trawls in Greece use more or less the same gear with minor modification, and métier selection is basically reflected as a choice of geographical sub-area and hauling depth. The limitations of using landings profiles to identify métiers and the need for further verification are discussed.

  20. Fish predation on brachyuran larvae and juveniles in the Pinheiros river, Guaratuba Bay, Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Paulo V. Costa

    2009-06-01

    Full Text Available Fish predation is thought to exert an important influence on the demographical dynamics of larvae and juveniles of estuarine brachyuran crabs but few studies have investigated this phenomenon in nature. In this study, fishes were captured during full moons (in January and February 2005, when many brachyuran species are known to release their larvae. Samples were carried out in the Pinheiros river, Guaratuba Bay, Paraná, Brazil. The stomach contents of collected fishes were surveyed to determine the species that are most likely to prey on brachyuran immature forms in this location. Two techniques were used to capture fishes: manual samplings, using a 5-mm mesh size net (1.8m depth, and bottom trawling with a 20-mm mesh size net. The collected specimens were fixed using 10% formaldehyde and preserved in 70% ethanol. A total of 2941 fishes of 43 different species were collected and the stomach contents of 962 individuals were analyzed in laboratory. Food items were identified and quantified. The fish species captured using manual nets that showed the highest number of preyed zoeae per stomach was the clupeid Platanichthys platana (Regan, 1917. Sphoeroides testudineus (Linnaeus, 1758 and Centropomus parallelus Poey, 1860 showed the highest levels of predation on megalopae. Of the fish species captured using trawl nets, Genidens genidens (Cuvier, 1829 showed the highest average number of zoeae per analyzed stomach and Bairdiella ronchus (Cuvier, 1830 was the most important predator on brachyuran megalopae and on young juveniles. The obtained data indicate that brachyuran crab restocking efforts performed in the Guaratuba Bay should include strategies to avoid or, at least, reduce the access of fishes to the released early juvenile stages, given the potential substantial losses caused by fish predation. Considering that, in general, predation potential was 8.5 times lower in juveniles than in megalopae, releasing immature forms produced in laboratory

  1. Dynamics of prey moving through a predator field: a model of migrating juvenile salmon

    Science.gov (United States)

    Petersen, J.H.; DeAngelis, D.L.

    2000-01-01

    The migration of a patch of prey through a field of relatively stationary predators is a situation that occurs frequently in nature. Making quantitative predictions concerning such phenomena may be difficult, however, because factors such as the number of the prey in the patch, the spatial length and velocity of the patch, and the feeding rate and satiation of the predators all interact in a complex way. However, such problems are of great practical importance in many management situations; e.g., calculating the mortality of juvenile salmon (smolts) swimming down a river or reservoir containing many predators. Salmon smolts often move downstream in patches short compared with the length of the reservoir. To take into account the spatial dependence of the interaction, we used a spatially-explicit, individual-based modeling approach. We found that the mortality of prey depends strongly on the number of prey in the patch, the downstream velocity of prey in the patch, and the dispersion or spread of the patch in size through time. Some counterintuitive phenomena are predicted, such as predators downstrean capturing more prey per predator than those upstream, even though the number of prey may be greatly depleted by the time the prey patch reaches the downstream predators. Individual-based models may be necessary for complex spatial situations, such as salmonid migration, where processes such as schooling occur at fine scales and affect system predictions. We compare some results to predictions from other salmonid models. (C) 2000 Elsevier Science Inc.

  2. Juvenile Justice Bulletin: Aftercare Services. Juvenile Justice Practices Series.

    Science.gov (United States)

    Gies, Steve V.

    This bulletin examines aftercare services that provide youth with comprehensive health, education, family, and vocational services upon their release from the juvenile justice system. Aftercare can be defined as reintegrative services that prepare out-of-home placed juveniles for reentry into the community by reestablishing the necessary…

  3. Miastenia gravis juvenil Juvenile myasthenia gravis

    Directory of Open Access Journals (Sweden)

    Oscar Papazian

    2009-01-01

    Full Text Available La miastenia gravis juvenil (MGJ es un trastorno crónico auto inmune en el cual existen anticuerpos séricos que al unirse a los receptores de acetilcolin nicotínicos de la membrana muscular de la placa motora alteran la transmisión neuromuscular. El resultado es fatiga muscular precoz con progresión a la parálisis durante estados de contracción muscular iterativos (movimientos o sostenidos (posturas y más raramente parálisis permanente durante el reposo. Los músculos inervados por los nervios craneales, especialmente los extraoculares y elevadores de los párpados, tienen más tendencia a la debilidad muscular persistente que los inervados por otros pares craneales y las extremidades. Las formas clínicas de presentación son generalizadas, oculares y respiratorias. El diagnóstico se sospecha mediante la anamnesia, la fatiga anormal se comprueba mediante el examen físico y la estimulación eléctrica iterativa del nervio que inerva al músculo afectado pero no paralizado. Se corrobora mediante la administración de inhibidores de la acetilcolin esterasa (IACE que al aumentar la cantidad de acetilcolin en la hendidura sináptica, corrigen la fatiga o la debilidad muscular transitoriamente. Se hace el diagnóstico de certeza mediante la demostración sérica de anticuerpos contra los receptores de acetilcolin (ACRA. El tratamiento es a largo plazo sintomático con IACE y etiopatogénico con inmunosupresores, plasmaféresis, gamma globulina endovenosa y timectomía. El curso es crónico. La remisión espontánea o después de tratamiento sintomático o etiopatogénico ocurre entre 1-10 años respectivamente. La mortalidad es prácticamente nula aun durantes las crisis miastenias gracias a la educación de padres, pacientes y público en general sobre el tema, al desarrollo del sistema de respuesta rápida de auxilio domiciliario y las unidades de cuidados intensivos y el empleo de la ventilación asistida profiláctica, plasmaféresis y

  4. An Ecosystem-Based Approach to Habitat Restoration Projects with Emphasis on Salmonids in the Columbia River Estuary, 2003 Technical Report.

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, G.; Thom, R.; Whiting, A. (Pacific Northwest National Laboratory)

    2003-11-01

    -listed salmon populations and native species using the CRE. The program's underlying principles are: (1) projects are founded on the best available ecological restoration science, implemented in an ecosystem context, and developed with the intent to restore relevant ecological processes; (2) projects incorporate adaptive management practices with testable hypotheses to track ecological responses to a given restoration effort; and (3) projects are implemented in a coordinated, open process and scientific results from monitoring and evaluation are communicated widely and readily accessible. With this goal and these principles in mind, we developed an approach for CRE habitat restoration. The intent of this document is to provide a scientific basis and implementation guidelines for a habitat restoration program designed to improve ecosystem functions and enhance juvenile salmonid survival in the CRE. The stepwise approach to CRE habitat restoration outlined is somewhat general and broad because the available scientific information is incomplete, e.g., juvenile salmon usage of various CRE wetland habitats. As new data become available, a more specific, detailed plan than was possible here can be produced as an outgrowth of this document. In conclusion, this document provides a scientific basis and implementation guidelines for a habitat restoration program designed to improve ecosystem functions and enhance juvenile salmonid survival in the CRE. As more experience is gained with CRE habitat restoration and scientific uncertainties are resolved, this document should be used as a basis for a detailed habitat restoration plan that specifically addresses (1) which habitat types offer the greatest ecological benefit to salmon, (2) the location of potential sites that if restored would likely provide these habitat types, and (3) how and when the restoration work should be done. This document supports the use of adaptive management so that all elements of salmonid habitat restoration

  5. Abundance, stock origin, and length of marked and unmarked juvenile Chinook salmon in the surface waters of greater Puget Sound

    Science.gov (United States)

    Rice, C.A.; Greene, C.M.; Moran, P.; Teel, D.J.; Kuligowski, D.R.; Reisenbichler, R.R.; Beamer, E.M.; Karr, J.R.; Fresh, K.L.

    2011-01-01

    This study focuses on the use by juvenile Chinook salmon Oncorhynchus tshawytscha of the rarely studied neritic environment (surface waters overlaying the sublittoral zone) in greater Puget Sound. Juvenile Chinook salmon inhabit the sound from their late estuarine residence and early marine transition to their first year at sea. We measured the density, origin, and size of marked (known hatchery) and unmarked (majority naturally spawned) juveniles by means of monthly surface trawls at six river mouth estuaries in Puget Sound and the areas in between. Juvenile Chinook salmon were present in all months sampled (April-November). Unmarked fish in the northern portion of the study area showed broader seasonal distributions of density than did either marked fish in all areas or unmarked fish in the central and southern portions of the sound. Despite these temporal differences, the densities of marked fish appeared to drive most of the total density estimates across space and time. Genetic analysis and coded wire tag data provided us with documented individuals from at least 16 source populations and indicated that movement patterns and apparent residence time were, in part, a function of natal location and time passed since the release of these fish from hatcheries. Unmarked fish tended to be smaller than marked fish and had broader length frequency distributions. The lengths of unmarked fish were negatively related to the density of both marked and unmarked Chinook salmon, but those of marked fish were not. These results indicate more extensive use of estuarine environments by wild than by hatchery juvenile Chinook salmon as well as differential use (e.g., rearing and migration) of various geographic regions of greater Puget Sound by juvenile Chinook salmon in general. In addition, the results for hatchery-generated timing, density, and length differences have implications for the biological interactions between hatchery and wild fish throughout Puget Sound. ?? American

  6. 75 FR 61642 - Fisheries of the Exclusive Economic Zone Off Alaska; Modified Nonpelagic Trawl Gear and Habitat...

    Science.gov (United States)

    2010-10-06

    ... Economic Zone Off Alaska; Modified Nonpelagic Trawl Gear and Habitat Conservation in the Bering Sea Subarea.... Matthew Island, and to allow for efficient flatfish harvest as the distribution of flatfish in the Bering... economic impact on the flatfish vessel fleet, the industry's participation in the modified gear...

  7. When does fishing lead to more fish? Community consequences of bottom trawl fisheries in demersal food webs

    NARCIS (Netherlands)

    Denderen, van P.D.; Kooten, van T.; Rijnsdorp, A.D.

    2013-01-01

    Bottom trawls are a globally used fishing gear that physically disturb the seabed and kill non-target organisms, including those that are food for the targeted fish species. There are indications that ensuing changes to the benthic invertebrate community may increase the availability of food and pro

  8. A simulation-based attempt to quantify the morphological component of size selection of Nephrops norvegicus in trawl codends

    DEFF Research Database (Denmark)

    Frandsen, Rikke; Herrmann, Bent; Madsen, Niels

    2010-01-01

    The selectivity for Nephrops (Nephrops norvegicus) in trawl codends generally is poor and the lack of steepness of the selection curve results in high discard rates and/or loss of legal-sized catch. This poor codend selectivity often is attributed to the irregular shape of Nephrops, which to some...

  9. Influence of twin and multi-rig trawl systems on CPUE in the Danish Norway lobster (Nephrops norvegicus) fishery

    DEFF Research Database (Denmark)

    Feekings, Jordan P.; Berg, Casper Willestofte; Krag, Ludvig Ahm;

    2016-01-01

    analyse catchrates of four target species, Norway lobster (Nephrops norvegicus), cod (Gadus morhua), plaice (Pleuronectesplatessa) and haddock (Melanogrammus aeglefinus), to try and understand how the use of multi-rig trawlshave altered catch rates within the Danish demersal trawl fishery over the last 16...

  10. Similar effects of bottom trawling and natural disturbance on composition and function of benthic communities across habitats

    DEFF Research Database (Denmark)

    van Denderen, Pieter Daniël; Bolam, S.G.; Hiddink, J.G.

    2015-01-01

    communities in similar ways. Both sources of disturbance caused declines in long-living, hard-bodied (exoskeleton) and suspension-feeding organisms. Given these similar impacts, there was no detectable trawling effect on communities exposed to high natural disturbance. Conversely, in 3 out of 5 areas with low...

  11. Benthic habitat characterisation of soft-bottom continental shelves: Integration of acoustic surveys, benthic samples and trawling disturbance intensity

    Science.gov (United States)

    de Juan, S.; Lo Iacono, C.; Demestre, M.

    2013-01-01

    Eleven sites were located on Mediterranean continental shelves to explore the link between the physical characteristics and epibenthic fauna from soft-sediment habitats. These sites, at 32-82 m in depth, were associated with fishing grounds and the trawling intensity was estimated at the site scale to assess the effects of trawling on benthic communities. Each site was surveyed with Multi-Beam (bathymetry and backscatter), side-scan sonar, benthic grabs and a surface dredge. The sites were clustered in three habitat types. Habitat 1, with moderate trawling disturbance, was characterised by homogeneous mud and associated epifauna that was also highly homogeneous across sites. Habitat 2, with sandy mud and scattered gravel and rocks, had a high abundance of sessile suspension feeders that probably attach to the coarser substratum and benefit from the low fishing disturbance in these sites. Habitat 3 included sites with heterogeneous sediments with maërl as the prevailing biocenosis and having the highest species richness, despite being subjected to variable trawling intensity. Statistical models were used to relate environmental parameters and the species abundance. More than 3 physical variables were necessary to explain the epifaunal patterns across sites, including the percentage of mud, sediment heterogeneity and fishing effort. These analyses are an essential step for extrapolating information from benthic samples to the larger scale of habitats, mapped through acoustic surveys. Despite this, a good integration is required between the mapping of physical habitat distribution and the ecological knowledge of communities.

  12. Similar effects of bottom trawling and natural disturbance on composition and function of benthic communities across habitats

    DEFF Research Database (Denmark)

    van Denderen, Pieter Daniël; Bolam, S.G.; Hiddink, J.G.

    2015-01-01

    communities in similar ways. Both sources of disturbance caused declines in long-living, hard-bodied (exoskeleton) and suspension-feeding organisms. Given these similar impacts, there was no detectable trawling effect on communities exposed to high natural disturbance. Conversely, in 3 out of 5 areas with low...

  13. Similar effects of bottom trawling and natural disturbance on composition and function of benthic communities across habitats

    DEFF Research Database (Denmark)

    van Denderen, Pieter Daniël; Bolam, S.G.; Hiddink, J.G.;

    2015-01-01

    bed shear stress, responses to trawling were detected and resulted in community compositions comparable with those in areas subject to high natural disturbance, with communities being composed of either small-sized, deposit-feeding animals or mobile scavengers and predators. The findings highlight...

  14. ASSESSMENT OF STOCK AND SPATIAL DISTRIBUTION OF SOLE (SOLEA SOLEA, L. IN ALBANIAN COAST USING RAPIDO TRAWL

    Directory of Open Access Journals (Sweden)

    Enton Spaho

    2012-06-01

    Full Text Available Common sole (Solea solea Linnaeus, 1758 is still not a specific target of fishery in Albania, but it represents an important target of the mixed-species catches of bottom trawlers and set netters operating in the coastal areas in the upper part of Albanian Adriatic Sea. Sole landings are low, amounting very few tonnes, but the demand will likely increase in the next future, because of the high quality of the fish fillet and the increase of consumers demand for wild sea fish. In order to identify the spawning areas and assess the spatial distribution and biomass of this species a rapido trawl survey was performed in year 2007. The smallest specimens were mostly concentrated in the shallowest stratum and the largest ones between 30 and 100 m depth. Solea Stock Biomass (SSB was 354 t, corresponding to 64% of the overall population recorded at sea at that time. In the context of fisheries, the Albanian fishing fleet involve a number of different fishing gears, while rapido trawl is introduced recently. The special technical and operating characteristics of rapido trawl makes it very effective in sole fishery and less harmful for the sea benthos and the species inhabiting it. This study aimed the estimation of spatial distribution of common sole and its biomass in the Albanian coast using rapido trawl gear.

  15. Using marine reserves to manage impact of bottom trawl fisheries requires consideration of benthic food-web interactions

    DEFF Research Database (Denmark)

    van Denderen, Pieter Daniël; Rijnsdorp, Adriaan D.; van Kooten, Tobias

    2016-01-01

    Marine protected areas (MPAs) are widely used to protect exploited fish species as well as to conserve marine habitats and their biodiversity. They have become a popular management tool also for bottom trawl fisheries, a common fishing technique on continental shelves worldwide. The effects of bo...

  16. Quality of coastal and estuarine essential fish habitats: estimations based on the size of juvenile common sole ( Solea solea L.)

    Science.gov (United States)

    Le Pape, O.; Holley, J.; Guérault, D.; Désaunay, Y.

    2003-12-01

    Survival and growth of early fish stages are maximal in coastal and estuarine habitats where natural shallow areas serve as nurseries for a variety of widely distributed species on the continental shelf. Processes occurring in these nursery grounds during the juvenile stage affect growth and may be important in regulating the year-class strength of fishes and population size. The need, therefore, exists to protect these essential fish habitats hence to develop indicators to estimate their quality. The purpose of the present study was to use the growth of juvenile sole as a means of comparing the quality of coastal and estuarine nursery habitats in the Bay of Biscay (France). These sole nurseries were clearly identified from studies based on trawl surveys carried out during the last two decades. The size of 1-group juveniles at the end of their second summer, as estimated from these surveys, is an indicator of growth in these habitats during the juvenile phase and can be used to compare habitat quality. A model taking into account the role of seawater temperature in spatial and interannual variations of juvenile size was developed to compare growth performance in the different nursery sectors. This study shows that the size of juvenile sole after two summers of life is not density-dependent, probably because the size of the population adapts to habitat capacity after high mortality during early-juvenile stages. Size is on one hand positively related to temperature and on the other hand higher in estuarine than in non-estuarine habitats. This high growth potential of juvenile fish in estuarine areas confirms the very important role played by estuaries as nursery grounds and the essential ecological interest of these limited areas in spite of their low water quality. If a general conclusion on habitat quality is to be reached about studies based on the growth of juvenile fish, it is necessary to use not only an integrative indicator of growth, like size

  17. Rearing in a distorted magnetic field disrupts the ‘map sense’ of juvenile steelhead trout

    Science.gov (United States)

    Putman, Nathan F.; Meinke, Amanda M.; Noakes, David L. G.

    2014-01-01

    We used simulated magnetic displacements to test orientation preferences of juvenile steelhead trout (Oncorhynchus mykiss) exposed to magnetic fields existing at the northernmost and southernmost boundaries of their oceanic range. Fish reared in natural magnetic conditions distinguished between these two fields by orienting in opposite directions, with headings that would lead fish towards marine foraging grounds. However, fish reared in a spatially distorted magnetic field failed to distinguish between the experimental fields and were randomly oriented. The non-uniform field in which fish were reared is probably typical of fields that many hatchery fish encounter due to magnetic distortions associated with the infrastructure of aquaculture. Given that the reduced navigational abilities we observed could negatively influence marine survival, homing ability and hatchery efficiency, we recommend further study on the implications of rearing salmonids in unnatural magnetic fields. PMID:24899681

  18. Rearing in a distorted magnetic field disrupts the 'map sense' of juvenile steelhead trout.

    Science.gov (United States)

    Putman, Nathan F; Meinke, Amanda M; Noakes, David L G

    2014-06-01

    We used simulated magnetic displacements to test orientation preferences of juvenile steelhead trout (Oncorhynchus mykiss) exposed to magnetic fields existing at the northernmost and southernmost boundaries of their oceanic range. Fish reared in natural magnetic conditions distinguished between these two fields by orienting in opposite directions, with headings that would lead fish towards marine foraging grounds. However, fish reared in a spatially distorted magnetic field failed to distinguish between the experimental fields and were randomly oriented. The non-uniform field in which fish were reared is probably typical of fields that many hatchery fish encounter due to magnetic distortions associated with the infrastructure of aquaculture. Given that the reduced navigational abilities we observed could negatively influence marine survival, homing ability and hatchery efficiency, we recommend further study on the implications of rearing salmonids in unnatural magnetic fields. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  19. Comparison of blood chemistry values for samples collected from juvenile chinook salmon by three methods

    Science.gov (United States)

    Congleton, J.L.; LaVoie, W.J.

    2001-01-01

    Thirteen blood chemistry indices were compared for samples collected by three commonly used methods: caudal transection, heart puncture, and caudal vessel puncture. Apparent biases in blood chemistry values for samples obtained by caudal transection were consistent with dilution with tissue fluids: alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), creatine kinase (CK), triglyceride, and K+ were increased and Na+ and Cl- were decreased relative to values for samples obtained by caudal vessel puncture. Some enzyme activities (ALT, AST, LDH) and K+ concentrations were also greater in samples taken by heart puncture than in samples taken by caudal vessel puncture. Of the methods tested, caudal vessel puncture had the least effect on blood chemistry values and should be preferred for blood chemistry studies on juvenile salmonids.

  20. Juvenile Dermatomyositis in Pregnancy

    Directory of Open Access Journals (Sweden)

    Anthony Emeka Madu

    2013-01-01

    Full Text Available Juvenile dermatomyositis has variable clinical presentations both in and outside of pregnancy. A literature review indicated that optimal maternal and fetal outcomes can be anticipated when the pregnancy is undertaken while the disease is in remission. Poorer outcomes are associated with flare-up of the disease in early pregnancy compared with exacerbation in the second or third trimester, when fetal prognosis is usually good. We present a case of JDM in pregnancy with disease exacerbation late in pregnancy and review of the relevant literature.

  1. Juvenile dermatomyositis in pregnancy.

    Science.gov (United States)

    Madu, Anthony Emeka; Omih, Edwin; Baguley, Elaine; Lindow, Stephen W

    2013-01-01

    Juvenile dermatomyositis has variable clinical presentations both in and outside of pregnancy. A literature review indicated that optimal maternal and fetal outcomes can be anticipated when the pregnancy is undertaken while the disease is in remission. Poorer outcomes are associated with flare-up of the disease in early pregnancy compared with exacerbation in the second or third trimester, when fetal prognosis is usually good. We present a case of JDM in pregnancy with disease exacerbation late in pregnancy and review of the relevant literature.

  2. Juvenile hyaline fibromatosis.

    Science.gov (United States)

    Larralde, M; Santos-Muñoz, A; Calb, I; Magariños, C

    2001-01-01

    Juvenile hyaline fibromatosis (JHF) is a rare autosomal recessive disease with onset in infancy or early childhood. It is characterized by papulonodular skin lesions, soft tissue masses, gingival hypertrophy, and flexion contractures of the large joints. The light and electron microscopic features are very distinctive. Here we report an 8-month-old boy with characteristic stiffness of the knees and elbows and pink confluent papules on the paranasal folds, and periauricular and perianal regions. He also had hard nodules all over the scalp and around the mouth, and severe gingival hypertrophy. Histologic and ultrastructural features were typical of JHF. Clinical features, pathology, and physiology are discussed.

  3. Visual surveys can reveal rather different 'pictures' of fish densities: Comparison of trawl and video camera surveys in the Rockall Bank, NE Atlantic Ocean

    Science.gov (United States)

    McIntyre, F. D.; Neat, F.; Collie, N.; Stewart, M.; Fernandes, P. G.

    2015-01-01

    Visual surveys allow non-invasive sampling of organisms in the marine environment which is of particular importance in deep-sea habitats that are vulnerable to damage caused by destructive sampling devices such as bottom trawls. To enable visual surveying at depths greater than 200 m we used a deep towed video camera system, to survey large areas around the Rockall Bank in the North East Atlantic. The area of seabed sampled was similar to that sampled by a bottom trawl, enabling samples from the towed video camera system to be compared with trawl sampling to quantitatively assess the numerical density of deep-water fish populations. The two survey methods provided different results for certain fish taxa and comparable results for others. Fish that exhibited a detectable avoidance behaviour to the towed video camera system, such as the Chimaeridae, resulted in mean density estimates that were significantly lower (121 fish/km2) than those determined by trawl sampling (839 fish/km2). On the other hand, skates and rays showed no reaction to the lights in the towed body of the camera system, and mean density estimates of these were an order of magnitude higher (64 fish/km2) than the trawl (5 fish/km2). This is probably because these fish can pass under the footrope of the trawl due to their flat body shape lying close to the seabed but are easily detected by the benign towed video camera system. For other species, such as Molva sp, estimates of mean density were comparable between the two survey methods (towed camera, 62 fish/km2; trawl, 73 fish/km2). The towed video camera system presented here can be used as an alternative benign method for providing indices of abundance for species such as ling in areas closed to trawling, or for those fish that are poorly monitored by trawl surveying in any area, such as the skates and rays.

  4. Juvenile Justice in Rural America.

    Science.gov (United States)

    Jankovic, Joanne, Ed.; And Others

    Producing a much-needed organized body of literature about rural juvenile justice, 14 papers (largely from the 1979 National Symposium on Rural Justice) are organized to identify current issues, identify forces causing changes in current systems, review programs responding to rural juvenile justice problems, and provide planning models to aid…

  5. Theoretical life history responses of juvenile Oncorhynchus mykiss to changes in food availability using a dynamic state-dependent approach

    Science.gov (United States)

    Romine, Jason G.; Benjamin, Joseph R.; Perry, Russell W.; Casal, Lynne; Connolly, Patrick J.; Sauter, Sally S.

    2013-01-01

    Marine subsidies can play an important role in the growth, survival, and migratory behavior of rearing juvenile salmonids. Availability of high-energy, marine-derived food sources during critical decision windows may influence the timing of emigration or the decision to forego emigration completely and remain in the freshwater environment. Increasing growth and growth rate during these decision windows may result in an altered juvenile population structure, which will ultimately affect the adult population age-structure. We used a state dependent model to understand how the juvenile Oncorhynchus mykiss population structure may respond to increased availability of salmon eggs in their diet during critical decision windows. Our models predicted an increase in smolt production until coho salmon eggs comprised more than 50 percent of juvenile O. mykiss diet at the peak of the spawning run. At higher-than intermediate levels of egg consumption, smolt production decreased owing to increasing numbers of fish adopting a resident life-history strategy. Additionally, greater growth rates decreased the number of age-3 smolts and increased the number of age-2 smolts. Increased growth rates with higher egg consumption also decreased the age at which fish adopted the resident pathway. Our models suggest that the introduction of a high-energy food source during critical periods of the year could be sufficient to increase smolt production.

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

    Science.gov (United States)

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

    2009-01-01

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

  7. Deep vision: an in-trawl stereo camera makes a step forward in monitoring the pelagic community.

    Directory of Open Access Journals (Sweden)

    Melanie J Underwood

    Full Text Available Ecosystem surveys are carried out annually in the Barents Sea by Russia and Norway to monitor the spatial distribution of ecosystem components and to study population dynamics. One component of the survey is mapping the upper pelagic zone using a trawl towed at several depths. However, the current technique with a single codend does not provide fine-scale spatial data needed to directly study species overlaps. An in-trawl camera system, Deep Vision, was mounted in front of the codend in order to acquire continuous images of all organisms passing. It was possible to identify and quantify of most young-of-the-year fish (e.g. Gadus morhua, Boreogadus saida and Reinhardtius hippoglossoides and zooplankton, including Ctenophora, which are usually damaged in the codend. The system showed potential for measuring the length of small organisms and also recorded the vertical and horizontal positions where individuals were imaged. Young-of-the-year fish were difficult to identify when passing the camera at maximum range and to quantify during high densities. In addition, a large number of fish with damaged opercula were observed passing the Deep Vision camera during heaving; suggesting individuals had become entangled in meshes farther forward in the trawl. This indicates that unknown numbers of fish are probably lost in forward sections of the trawl and that the heaving procedure may influence the number of fish entering the codend, with implications for abundance indices and understanding population dynamics. This study suggests modifications to the Deep Vision and the trawl to increase our understanding of the population dynamics.

  8. Juvenile arthritis and uveitis.

    Science.gov (United States)

    Kanski, J J

    1990-01-01

    The association between juvenile arthritis and uveitis is reviewed. Some children with the HLA-B27 related spondyloarthropathies develop anterior uveitis. About 20% of patients with juvenile rheumatoid arthritis (JRA) who are negative for IgM rheumatoid factor develop a frequently bilateral, nongranulomatous chronic anterior uveitis. Risk factors for uveitis in JRA patients are: female gender, pauciarticular onset of arthritis, presence of circulating antinuclear antibodies, and the antigens HLA-DW5 and HLA-DPw2. Uveitis is rare after seven years or more have elapsed from the onset of arthritis. The visual prognosis in patients with uveitis is good in 25% and fair in 50%. The remaining 25% develop visual impairment from complicated cataract and/or secondary inflammatory glaucoma. The potential benefit of cytotoxic agents in the treatment of intractable uveitis is outweighed by the risk of serious side effects. The management of secondary inflammatory glaucoma is unsatisfactory, but the results of treatment of complicated cataracts by lensectomy-vitrectomy are good.

  9. Aggressive juvenile mandibular fibromatosis.

    Science.gov (United States)

    Ivanov, Georgi P; Atanasov, Dimitar T; Anavi, Beniamin L

    2013-01-01

    Aggressive juvenile fibromatosis of the jawbones is a rare tumor presenting as infiltrative mass with unpredictable evolution. We report herein a 17-year-old student with a 6-month history of radiologically proven resorption of a part of the mandible, lingual displacement of tooth 34 and malocclusion. Alveolar ridge resorption and three dark-brown foci in the bone were seen after the tooth was extracted. Histological study showed the tumor tissue to have a bundle-like structure; immunohistochemically it was positive for vimentin, smooth muscle actin, beta-catenin, Ki-67 (5%), and negative for desmin and cytokeratin 34bE12. The golden standard in the diagnostics of desmoid fibromatoses is the nuclear or membrane expression of beta-catenin, which is found in 90% of the cases. Differential diagnosis include mandibular fibroma, well-differentiated fibrosarcoma, fibrosing histiocytoma, and infiltration from adjacent soft-tissue tumor. Aggressive juvenile fibromatosis should be managed by radical excision. Local recurrences are not rare, but metastases do not develop. In rare cases this type of fibromatosis has been known to regress spontaneously. Aggressive fibromatosis is a diagnostic challenge, since it remains in the grey zone between benign and malignant lesions of the oral cavity.

  10. Distribution and habitat associations of juvenile Common Snook in the lower Rio Grande, Texas

    Science.gov (United States)

    Huber, Caleb G.; Grabowski, Timothy B.; Patino, Reynaldo; Pope, Kevin L.

    2014-01-01

    Common Snook Centropomus undecimalis were once abundant off the Texas coast, but these populations are now characterized by low abundance and erratic recruitment. Most research concerning Common Snook in North America has been conducted in Florida and very little is known about the specific biology and habitat needs of Common Snook in Texas. The primary objective of this study was to describe the habitat use patterns of juvenile Common Snook and their role in the fish assemblage in the lower portion of the Rio Grande, Texas. Secondarily, we documented the relationship between age and juvenile reproductive development. Fish were collected during January–March 2006 from the lower 51.5 km of the Rio Grande using a bottom trawl and boat-mounted electrofisher. Measurements of water quality and other habitat traits were recorded at each sampling site. We captured 225 Common Snook exclusively in freshwater habitats above river kilometer 12.9. The distribution of juvenile Common Snook was not random, but influenced primarily by turbidity and dissolved oxygen. Sex differentiation and gonadal development based on histological examination of gonads established that age-1 and age-2 Common Snook were juvenile, prepubertal males. There was no difference between the age groups in their overall distribution in the river. However, age-2 Common Snook were associated with deeper areas with faster currents, higher conductivity, and steeper banks. Overall, Common Snook in the lower Rio Grande show substantial differences in habitat use than their counterparts in other parts of the range of the species, but it is unclear whether this is due to differences in habitat availability, behavioral plasticity, or some combination thereof.

  11. Modification of a salmonid alphavirus replicon vector for enhanced expression of heterologous antigens.

    Science.gov (United States)

    Guo, Tz-Chun; Johansson, Daniel X; Liljeström, Peter; Evensen, Øystein; Haugland, Øyvind

    2015-03-01

    A salmonid alphavirus (SAV) replicon has been developed to express heterologous antigens but protein production was low to modest compared with terrestrial alphavirus replicons. In this study, we have compared several modifications to a SAV replicon construct and analysed their influence on foreign gene expression. We found that an insertion of a translational enhancer consisting of the N-terminal 102 nt of the capsid gene, together with a nucleotide sequence encoding the foot-and-mouth disease virus (FMDV) 2A peptide, caused a significant increase in EGFP reporter gene expression. The importance of fusing a hammerhead (HH) ribozyme sequence at the 5' end of the viral genome was also demonstrated. In contrast, a hepatitis D virus ribozyme (HDV-RZ) sequence placed at the 3' end did not augment expression of inserted genes. Taken together, we have developed a platform for optimized antigen production, which can be applied for immunization of salmonid fish in the future.

  12. Inflammatory and regenerative responses in salmonids following mechanical tissue damage and natural infection

    DEFF Research Database (Denmark)

    Ingerslev, Hans-Christian; Lunder, Tor; Nielsen, Michael Engelbrecht

    2010-01-01

    Locale responses in muscle tissue against either a sterile tissue damage or infection were compared in salmonid fish in order to examine the inflammatory responses and regeneration of tissue. From higher vertebrates both damage and infection are known to cause inflammation since DAMPs released from...... injured cells as well as PAMPs from the surface of pathogens are immunogenic. To examine this in salmonid fishes, Atlantic salmon (Salmo salar) were infected with Moritella viscosus, the causative agent of winter ulcer. Muscle tissue was sampled from infected fish at 4, 7 and 14 days post infection...... are coding for immunological factors and tissue regeneration. Locale, inflammatory responses were seen as strong up-regulation of IL-1β and IL-8 in both groups of fish, but it was more pronounced in infected fish. Expression of the toll-like receptors showed induction of TLR-5m following infection, but TLR-9...

  13. Modelling the Influence of Long-Term Hydraulic Conditions on Juvenile Salmon Habitats in AN Upland Scotish River

    Science.gov (United States)

    Fabris, L.; Malcolm, I.; Millidine, K. J.; Buddendorf, B.; Tetzlaff, D.; Soulsby, C.

    2015-12-01

    Wild Atlantic salmon populations in Scottish rivers constitute an important economic and recreational resource, as well as being a key component of biodiversity. Salmon have very specific habitat requirements at different life stages and their distribution is therefore strongly influenced by a complex suite of biological and physical controls. Previous research has shown that stream hydrodynamics and channel morphology have a strong influence on the distribution and density of juvenile salmon. Here, we utilise a unique 20 year data set of spatially distributed juvenile salmon densities derived from annual electro-fishing surveys in an upland Scottish river. We examine to what extent the spatial and temporal variability of in-stream hydraulics regulates the spatial and temporal variability in the performance and density of juvenile salmon. A 2-D hydraulic model (River2D) is used to simulate water velocity and water depth under different flow conditions for seven different electro-fishing sites. The selected sites represent different hydromorphological environments including plane-bed, step-pool and pool riffle reaches. The bathymetry of each site was characterised using a total station providing an accurate DTM of the bed, and hydraulic simulations were driven by 20 year stream flow records. Habitat suitability curves, based on direct observations during electro-fishing surveys, were produced for a range of hydraulic indices for juvenile salmon. The hydraulic simulations showed marked spatial differences in juvenile habitat quality both within and between reaches. They also showed marked differences both within and between years. This is most evident in extreme years with wet summers when salmon feeding opportunities may be constrained. Integration of hydraulic habitat models, with fish preference curves and the long term hydrological data allows us to assess whether long-term changes in hydroclimate may be affecting juvenile salmonid populations in the study stream

  14. Juvenile justice mental health services.

    Science.gov (United States)

    Thomas, Christopher R; Penn, Joseph V

    2002-10-01

    As the second century of partnership begins, child psychiatry and juvenile justice face continuing challenges in meeting the mental health needs of delinquents. The modern juvenile justice system is marked by a significantly higher volume of cases, with increasingly complicated multiproblem youths and families with comorbid medical, psychiatric, substance abuse disorders, multiple family and psychosocial adversities, and shrinking community resources and alternatives to confinement. The family court is faced with shrinking financial resources to support court-ordered placement and treatment programs in efforts to treat and rehabilitate youths. The recognition of high rates of mental disorders for incarcerated youth has prompted several recommendations for improvement and calls for reform [56,57]. In their 2000 annual report, the Coalition for Juvenile Justice advocated increased access to mental health services that provide a continuum of care tailored to the specific problems of incarcerated youth [58]. The specific recommendations of the report for mental health providers include the need for wraparound services, improved planning and coordination between agencies, and further research. The Department of Justice, Office of Juvenile Justice and Delinquency Prevention has set three priorities in dealing with the mental health needs of delinquents: further research on the prevalence of mental illness among juvenile offenders, development of mental health screening assessment protocols, and improved mental health services [59]. Other programs have called for earlier detection and diversion of troubled youth from juvenile justice to mental health systems [31,56]. Most recently, many juvenile and family courts have developed innovative programs to address specific problems such as truancy or substance use and diversionary or alternative sentencing programs to deal with first-time or nonviolent delinquents. All youths who come in contact with the juvenile justice system

  15. Comparing stream-specific to generalized temperature models to guide salmonid management in a changing climate

    Science.gov (United States)

    Andrew K. Carlson,; William W. Taylor,; Hartikainen, Kelsey M.; Dana M. Infante,; Beard, Douglas; Lynch, Abigail

    2017-01-01

    Global climate change is predicted to increase air and stream temperatures and alter thermal habitat suitability for growth and survival of coldwater fishes, including brook charr (Salvelinus fontinalis), brown trout (Salmo trutta), and rainbow trout (Oncorhynchus mykiss). In a changing climate, accurate stream temperature modeling is increasingly important for sustainable salmonid management throughout the world. However, finite resource availability (e.g. funding, personnel) drives a tradeoff between thermal model accuracy and efficiency (i.e. cost-effective applicability at management-relevant spatial extents). Using different projected climate change scenarios, we compared the accuracy and efficiency of stream-specific and generalized (i.e. region-specific) temperature models for coldwater salmonids within and outside the State of Michigan, USA, a region with long-term stream temperature data and productive coldwater fisheries. Projected stream temperature warming between 2016 and 2056 ranged from 0.1 to 3.8 °C in groundwater-dominated streams and 0.2–6.8 °C in surface-runoff dominated systems in the State of Michigan. Despite their generally lower accuracy in predicting exact stream temperatures, generalized models accurately projected salmonid thermal habitat suitability in 82% of groundwater-dominated streams, including those with brook charr (80% accuracy), brown trout (89% accuracy), and rainbow trout (75% accuracy). In contrast, generalized models predicted thermal habitat suitability in runoff-dominated streams with much lower accuracy (54%). These results suggest that, amidst climate change and constraints in resource availability, generalized models are appropriate to forecast thermal conditions in groundwater-dominated streams within and outside Michigan and inform regional-level salmonid management strategies that are practical for coldwater fisheries managers, policy makers, and the public. We recommend fisheries professionals reserve resource

  16. Lake Ontario Deepwater Sculpin bottom trawl catch and biological data, 1996-2016

    Science.gov (United States)

    Weidel, Brian C.

    2016-01-01

    Deepwater Sculpin are important in oligotrophic lakes as one of the few fishes that use deep profundal habitats and link invertebrates in those habitats to piscivores. In Lake Ontario the species was once abundant, however drastic declines in the mid-1900s led some to suggest the species had been extirpated and ultimately led Canadian and U.S. agencies to elevate the species’ conservation status in the 1990s. Following multiple decades of annual surveys with no captures, Deepwater Sculpin were first caught in low numbers in 1996 and by the early 2000s there were indications of population recovery. These data sets were used to update the status of Lake Ontario Deepwater Sculpin through 2016 to inform resource management and conservation. The entire data set includes tables for bottom trawl catches, length frequency, individual fish length weight, as well as gonad weight.

  17. Improving selectivity of the Baltic cod pelagic trawl fishery: Experiments to assess the next step

    DEFF Research Database (Denmark)

    Madsen, Niels; Tschernij, Vesa; Holst, René

    2010-01-01

    Due to declining cod (Gadus morhua) stocks, the Baltic Sea was one of the first areas regulated by the European Communities where selective escape windows were implemented to improve the exploitation pattern. Increasing discard rates and the potential for a significant increase of the spawning...... stock and the yield of the fishery are important reasons to further improve the selectivity of the fishery and to asses the potential next step in this process. In this study, we tested three relatively different design concepts, in the Baltic cod pelagic trawl fishery, that are relevant to past...... or present legislation and that were developed to meet requirements of increased selectivity performance. A standard nominal 135 mm diamond mesh codend, a codend with two nominal 125 mm bottom windows, and a codend with a nominal 125 mm nominal top window were tested using the covered codend method. A Danish...

  18. Environmental DNA from seawater samples correlate with trawl catches of Subarctic, deepwater fishes

    DEFF Research Database (Denmark)

    Thomsen, Philip Francis; Møller, Peter Rask; Sigsgaard, Eva Egelyng;

    2016-01-01

    in fisheries. Nevertheless, our study demonstrates that eDNA reads can be used as a qualitative and quantitative proxy for marine fish assemblages in deepwater oceanic habitats. This relates directly to applied fisheries as well as to monitoring effects of ongoing climate change on marine biodiversity......Remote polar and deepwater fish faunas are under pressure from ongoing climate change and increasing fishing effort. However, these fish communities are difficult to monitor for logistic and financial reasons. Currently, monitoring of marine fishes largely relies on invasive techniques...... such as bottom trawling, and on official reporting of global catches, which can be unreliable. Thus, there is need for alternative and non-invasive techniques for qualitative and quantitative oceanic fish surveys. Here we report environmental DNA (eDNA) metabarcoding of seawater samples from continental slope...

  19. The effects of 118 years of industrial fishing on UK bottom trawl fisheries.

    Science.gov (United States)

    Thurstan, Ruth H; Brockington, Simon; Roberts, Callum M

    2010-05-04

    In 2009, the European Commission estimated that 88% of monitored marine fish stocks were overfished, on the basis of data that go back 20 to 40 years and depending on the species investigated. However, commercial sea fishing goes back centuries, calling into question the validity of management conclusions drawn from recent data. We compiled statistics of annual demersal fish landings from bottom trawl catches landing in England and Wales dating back to 1889, using previously neglected UK Government data. We then corrected the figures for increases in fishing power over time and a recent shift in the proportion of fish landed abroad to estimate the change in landings per unit of fishing power (LPUP), a measure of the commercial productivity of fisheries. LPUP reduced by 94%-17-fold--over the past 118 years. This implies an extraordinary decline in the availability of bottom-living fish and a profound reorganization of seabed ecosystems since the nineteenth century industrialization of fishing.

  20. Differential invasion success of salmonids in southern Chile: patterns and hypotheses

    Science.gov (United States)

    Arismendi, Ivan; Penaluna, Brooke E.; Dunham, Jason B.; García de Leaniz, Carlos; Soto, Doris; Fleming, Ian A.; Gomez-Uchidam, Daniel; Gajardo, Gonzalo; Vargas, Pamela V.; León-Muñoz, Jorge

    2014-01-01

    Biological invasions create complex ecological and societal issues worldwide. Most of the knowledge about invasions comes only from successful invaders, but less is known about which processes determine the differential success of invasions. In this review, we develop a framework to identify the main dimensions driving the success and failure of invaders, including human influences, characteristics of the invader, and biotic interactions. We apply this framework by contrasting hypotheses and available evidence to explain variability in invasion success for 12 salmonids introduced to Chile. The success of Oncorhynchus mykiss and Salmo trutta seems to be influenced by a context-specific combination of their phenotypic plasticity, low ecosystem resistance, and propagule pressure. These well-established invaders may limit the success of subsequently introduced salmonids, with the possible exception of O. tshawytscha, which has a short freshwater residency and limited spatial overlap with trout. Although propagule pressure is high for O. kisutch and S. salar due to their intensive use in aquaculture, their lack of success in Chile may be explained by environmental resistance, including earlier spawning times than in their native ranges, and interactions with previously established and resident Rainbow Trout. Other salmonids have also failed to establish, and they exhibit a suite of ecological traits, environmental resistance, and limited propagule pressure that are variably associated with their lack of success. Collectively, understanding how the various drivers of invasion success interact may explain the differential success of invaders and provide key guidance for managing both positive and negative outcomes associated with their presence.

  1. The Design and Analysis of Salmonid Tagging Studies in the Columbia Basin : Volume II: Experiment Salmonid Survival with Combined PIT-CWT Tagging.

    Energy Technology Data Exchange (ETDEWEB)

    Newman, Ken

    1997-06-01

    Experiment designs to estimate the effect of transportation on survival and return rates of Columbia River system salmonids are discussed along with statistical modeling techniques. Besides transportation, river flow and dam spill are necessary components in the design and analysis otherwise questions as to the effects of reservoir drawdowns and increased dam spill may never be satisfactorily answered. Four criteria for comparing different experiment designs are: (1) feasibility, (2) clarity of results, (3) scope of inference, and (4) time to learn. In this report, alternative designs for conducting experimental manipulations of smolt tagging studies to study effects of river operations such as flow levels, spill fractions, and transporting outmigrating salmonids around dams in the Columbia River system are presented. The principles of study design discussed in this report have broad implications for the many studies proposed to investigate both smolt and adult survival relationships. The concepts are illustrated for the case of the design and analysis of smolt transportation experiments. The merits of proposed transportation studies should be measured relative to these principles of proper statistical design and analysis.

  2. Miranda Rights: Implications for Juveniles with Disabilities

    Science.gov (United States)

    Katsiyannis, Antonis; Barrett, David E.; Losinski, Mickey L.

    2011-01-01

    Juvenile delinquency in the United States has been a persistent concern for decades. Consequently, because more juveniles have been referred to juvenile court and the arrest rate of preteen offenders has increased to almost three times that of older youth, the persistent and often controversial issue of the capacity of juvenile offenders to waive…

  3. Common dolphin (Delphinus delphis bycatch in New Zealand commercial trawl fisheries.

    Directory of Open Access Journals (Sweden)

    Finlay N Thompson

    Full Text Available Marine mammals are regularly reported as bycatch in commercial and artisanal fisheries, but data are often insufficient to allow assessment of these incidental mortalities. Observer coverage of the mackerel trawl fishery in New Zealand waters between 1995 and 2011 allowed evaluation of common dolphin Delphinus delphis bycatch on the North Island west coast, where this species is the most frequently caught cetacean. Observer data were used to develop a statistical model to estimate total captures and explore covariates related to captures. A two-stage Bayesian hurdle model was used, with a logistic generalised linear model predicting whether any common dolphin captures occurred on a given tow of the net, and a zero-truncated Poisson distribution to estimate the number of dolphin captures, given that there was a capture event. Over the 16-year study period, there were 119 common dolphin captures reported on 4299 observed tows. Capture events frequently involved more than one individual, with a maximum of nine common dolphin observed caught in a single tow. There was a peak of 141 estimated common dolphin captures (95% c.i.: 56 to 276; 6.27 captures per 100 tows in 2002-03, following the marked expansion in annual effort in this fishery to over 2000 tows. Subsequently, the number of captures fluctuated although fishing effort remained relatively high. Of the observed capture events, 60% were during trawls where the top of the net (headline was <40 m below the surface, and the model determined that this covariate best explained common dolphin captures. Increasing headline depth by 21 m would halve the probability of a dolphin capture event on a tow. While lack of abundance data prevents assessment of the impact of these mortalities on the local common dolphin population, a clear recommendation from this study is the increasing of headline depth to reduce common dolphin captures.

  4. Common dolphin (Delphinus delphis) bycatch in New Zealand commercial trawl fisheries.

    Science.gov (United States)

    Thompson, Finlay N; Abraham, Edward R; Berkenbusch, Katrin

    2013-01-01

    Marine mammals are regularly reported as bycatch in commercial and artisanal fisheries, but data are often insufficient to allow assessment of these incidental mortalities. Observer coverage of the mackerel trawl fishery in New Zealand waters between 1995 and 2011 allowed evaluation of common dolphin Delphinus delphis bycatch on the North Island west coast, where this species is the most frequently caught cetacean. Observer data were used to develop a statistical model to estimate total captures and explore covariates related to captures. A two-stage Bayesian hurdle model was used, with a logistic generalised linear model predicting whether any common dolphin captures occurred on a given tow of the net, and a zero-truncated Poisson distribution to estimate the number of dolphin captures, given that there was a capture event. Over the 16-year study period, there were 119 common dolphin captures reported on 4299 observed tows. Capture events frequently involved more than one individual, with a maximum of nine common dolphin observed caught in a single tow. There was a peak of 141 estimated common dolphin captures (95% c.i.: 56 to 276; 6.27 captures per 100 tows) in 2002-03, following the marked expansion in annual effort in this fishery to over 2000 tows. Subsequently, the number of captures fluctuated although fishing effort remained relatively high. Of the observed capture events, 60% were during trawls where the top of the net (headline) was dolphin captures. Increasing headline depth by 21 m would halve the probability of a dolphin capture event on a tow. While lack of abundance data prevents assessment of the impact of these mortalities on the local common dolphin population, a clear recommendation from this study is the increasing of headline depth to reduce common dolphin captures.

  5. Juvenile prison in parallel legislation

    Directory of Open Access Journals (Sweden)

    Lutovac Mitar

    2016-01-01

    Full Text Available The need for punishment of juveniles occurred from the time when there was no clear line separating them from the adult criminal population. At the same time, the evolution of the juvenile punishment is not in itself involve substantial changes to their criminal status. On the contrary, the status of minors in society did not show serious differences regarding the status of young adults, as well as the adult elderly. On the other hand, on the ground of their punishment is recorded deviations that go in the direction of application of mild corporal punishment. Closing the minor was performed in a physically separate parts of the general penal institutions with the use of a lower degree of restrictions while serving juvenile prison. Due to the different treatment of minors during the evolution of their criminal status leads to their different treatment in comparative law. That is why we are witnessing the existence of numerous differences in the juvenile punishment in some countries in the world. On the European continent there is a wide range of different legal solutions when it comes to punishing juveniles. There are considerable differences in the procedure pronouncing juvenile prison and in particular penal treatment of juveniles in penitentiary institutions. For these reasons, the author has decided to show the basic statutory provisions in the part that relates to the issue of punishment of minors in the legislation of individual countries.

  6. Update on juvenile myasthenia gravis.

    Science.gov (United States)

    Liew, Wendy K M; Kang, Peter B

    2013-12-01

    Juvenile myasthenia gravis is a relatively rare autoimmune neuromuscular disorder. The pathophysiology of juvenile myasthenia gravis is similar to that of adult myasthenia gravis, though there remain important differences regarding presentation and therapeutic options. We review the pathophysiology, clinical presentation, and treatment options for juvenile myasthenia gravis. Randomized clinical studies of myasthenia gravis have been carried out primarily in adult populations. As juvenile myasthenia gravis is rare, it has been difficult to collect prospective randomized controlled data to evaluate treatment outcomes and efficacy. A recent retrospective series suggests that, as in adult myasthenia gravis, thymectomy is a viable therapeutic option for selected cases of generalized juvenile myasthenia gravis. This is corroborated by the clinical experience of the authors in a referral center with a cohort of patients affected by juvenile myasthenia gravis over a number of years. Recent studies illustrate that some, but not all, adult research on myasthenia gravis is applicable to children and adolescents with juvenile myasthenia gravis. Adult research can inform pediatric studies, but should not be regarded as a substitute for dedicated research in those populations.

  7. Juvenile chronic arthritis.

    Science.gov (United States)

    Southwood, T R; Woo, P

    1995-05-01

    The nomenclature and classification criteria for arthritis in children should be dealt with initially as separate issues, although they are undoubtedly intertwined. The classification criteria should aim to delineate homogeneous patient populations, yet should be flexible enough to incorporate advances in disease knowledge. It should be recognized that arriving at an international consensus for classification criteria will merely provide a set of operational definitions to facilitate research, and not a set of diagnostic criteria. Indeed the only point to obtaining consensus is to begin a process of systematic ongoing review of the criteria. The labels attached to any of these diseases should facilitate accurate communication. In view of the heterogeneous nature of childhood arthritis, consideration should be given to using a broad umbrella term such as juvenile or childhood arthritis only for communicating with the lay public. Medical nomenclature should be formulated to reflect accurately homogeneous subgroups of arthritis, and should not artificially proscribe a relationship between paediatric and adult disease.

  8. [Juvenile idiopathic arthritis].

    Science.gov (United States)

    Herlin, Troels

    2002-08-19

    The new classification of juvenile idiopathic arthritis (JIA) is described in this review. Clinical characteristics divide JIA in to subtypes: systemic, oligoarticular (persistent and extended type), RF-positive and--negative polyarticular, enthesitis-related arthritis and psoriatic arthritis. In addition to the clinical characteristics, genetic and biochemical differences suggest that JIA could be regarded as a general term covering various diseases. Complications described are uveitis, temporomandibular joint affection and growth disturbances. The therapeutic strategy should be planned individually according to age, subtype and disease activity and carried out as teamwork with several specialties. Drugs showing significant effectiveness in controlled studies are primarily methotrexate and sulphasalazine. An immunomodulating agent, etanercept, a soluble TNF alpha-receptor fusion protein, has shown a promising effect in severe polyarticular JIA refractory to methotrexate treatment.

  9. Juvenile hyaline fibromatosis

    Directory of Open Access Journals (Sweden)

    Jayashree Krishnamurthy

    2011-01-01

    Full Text Available Juvenile hyaline fibromatosis is a rare, autosomal-recessive disease characterized by papular and nodular skin lesions, gingival hyperplasia, joint contractures and bone involvement in variable degrees. It is a connective tissue disorder with aberrant synthesis of glycosaminoglycans by fibroblasts. We report a 5-year-old female born of first-degree consanguineous marriage who presented with multiple, recurrent, painless, variable-sized nodules. Fine needle aspiration cytology smears and the subsequent histopathological examination from the nodules showed benign spindle cells in a Periodic acid Schiff-positive myxoid background. The disease has a relentlessly progressive course, with most patients surviving only up to the 4 th decade. As of now, there is no specific treatment for this disorder. Genetic counseling is essential to explain to parents about a 25% chance of having a diseased baby in any pregnancy. With the gene being mapped recently, techniques for antenatal diagnosis are likely to be established.

  10. [JUVENILE DERMATOMYOSITIS AND CALCINOSIS].

    Science.gov (United States)

    Zhvania, M

    2015-01-01

    Juvenile Dermatomiositis (JD) is autoimmune disease that progresses with time; JD's main differentiated syndromes are rash on the skin, poor function of muscles, and often developing invalidism. If the health practitioners manage to diagnose the JD on an early stage and prescribe the adequate treatment the disease will not progress aggressively. This approach is tangible for practical rheumatology and pediatric. The article aims to present the reasons of the development of the JD and calcinosis. The study based on the description of the patients with JD. There are distinguished the main symptoms of the disease in children: frequent and acute developments of muscles calcinosis, occasionally with diffuse character followed with hypotrophy of the muscles, contractures and invalidism. One of the patient cases that describe the article is the thirteen-year boy with JD indicating repeated sequence of the disease, with diffusive calcinosis, cellulitis followed with secondary infection and impaired vision.

  11. Juvenile idiopathic arthritis

    Directory of Open Access Journals (Sweden)

    Krupa H Bhatt

    2014-01-01

    Full Text Available Juvenile Idiopathic Arthritis (JIA is the most chronic musculoskeletal disease of pediatric population. The chronic course of disease has a great impact on oral health. Temporomandibular joint is involved in JIA causing limited mouth opening with progressive open bite, retrognathia, microgenia and bird like appearance. Joints of upper and lower extremities are also involved. Effect on upper limb function leads to difficulty with fine motor movements required for brushing and flossing. This increases incidence of caries and periodontal disease in children. The cause of JIA is still poorly understood and none of the available drugs for JIA can cure the disease. However, prognosis has improved as a result of progress in disease classification and management. The dental practitioner should be familiar with the symptoms and oral manifestations of JIA to help manage as multidisciplinary management is essential.

  12. First Receiver and Shorebased Processor Data - Economic Data Collection for Monitoring the Economic Effects of the West Coast Groundfish Trawl Rationalization Program

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project was initiated in response to regulation 50 CFR 660.114, which mandates that economic data be collected from every participant in the trawl...

  13. Catcher Processor Cost Earnings Data - Economic Data Collection for Monitoring the Economic Effects of the West Coast Groundfish Trawl Rationalization Program

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project was initiated in response to regulation 50 CFR 660.114, which mandates that economic data be collected from every participant in the trawl...

  14. Catcher Vessel Cost Earnings Data - Economic Data Collection for Monitoring the Economic Effects of the West Coast Groundfish Trawl Rationalization Program

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project was initiated in response to regulation 50 CFR 660.114, which mandates that economic data be collected from every participant in the trawl...

  15. AFSC/RACE/SAP: Detailed Crab Data From NOAA Fisheries Service Annual Eastern Bering Sea Summer Bottom Trawl Surveys 1975 - 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains detailed crab data collected from the annual NOAA/NMFS/AFSC/RACE crab-groundfish bottom trawl survey of the eastern Bering Sea continental...

  16. Groundfish/Shrimp and Red Snapper trawl surveys conducted in the Gulf of Mexico from 1990-01-01 to 2014-12-30 (NCEI Accession 0147703)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Southeast Fisheries Science Center Mississippi Laboratories has conducted standardized groundfish trawl surveys in the Gulf of Mexico since 1987. Prior to 1987,...

  17. Juvenile homosexual homicide.

    Science.gov (United States)

    Myers, Wade C; Chan, Heng Choon Oliver

    2012-01-01

    Limited information exists on juvenile homosexual homicide (JHH), that is, youths who perpetrate sexual homicides against same-sex victims. Only a handful of cases from the United States and internationally have been described in the literature. This study, the first of its kind, examines the epidemiology, victimology, victim-offender relationship, and weapon-use patterns in JHH offenders using a large U.S. database on homicide spanning three decades. The data for this study were derived from the Federal Bureau of Investigation's Supplementary Homicide Reports (SHRs) for the years 1976 through 2005. A total of 93 cases of JHH were identified. On average, three of these crimes occurred annually in the U.S., and there was a marked decline in its incidence over the study period. Ninety-five percent were male offender-male victim cases and 5% were female offender-female victim cases. JHH offenders were over-represented amongst all juvenile sexual murderers, similar to their adult counterparts. The majority of these boys were aged 16 or 17 and killed adult victims. They were significantly more likely to kill adult victims than other age groups, to be friends or acquaintances of the victims, and to use contact/edged weapons or firearms. Most offenders killed same-race victims, although Black offenders were significantly more likely than White offenders to kill interracially. A case report is provided to illustrate JHH. Further research is needed to promote our understanding of the pathogenesis, etiology, and associated risk factors for this aberrant form of murder by children.

  18. Prey consumption by the juvenile soles, Solea solea and Solea senegalensis, in the Tagus estuary, Portugal

    Science.gov (United States)

    Vinagre, C.; Cabral, H. N.

    2008-06-01

    The soles Solea solea and Solea senegalensis are marine flatfish that use coastal and estuarine nursery grounds, which generally present high food availability, refuge from predators and favourable conditions for rapid growth. Two important nursery grounds for these species juveniles have been identified in the Tagus estuary, one in the upper part of the estuary (nursery A) and another in the south bank (nursery B). While S. solea is only present at the uppermost nursery area, S. senegalensis is present at both nurseries. Although they are among the most important predators in these nursery grounds, there are no estimates on their food consumption or on the carrying capacity of the system for soles. The Elliott and Persson [1978. The estimation of daily rates of food consumption for fish. Journal of Animal Ecology 47, 977-993] model was used to estimate food consumption of both species juveniles in both nursery areas, taking into account gastric evacuation rates (previously determined) and 24 h sampling surveys, based on beam-trawl catches carried out every 3 h, in the summer of 1995. Monthly beam trawls were performed to determine sole densities over the summer. Density estimates and daily food consumption values were used to calculate total consumption over the summer period. Sediment samples were taken for the estimation of prey densities and total biomass in the nursery areas. Daily food consumption was lower for S. solea (0.030 g wet weight d -1) than for S. senegalensis (0.075 g wet weight d -1). It was concluded that thermal stress may be an important factor hindering S. solea's food consumption in the warmer months. Total consumption of S. solea over the summer (90 days) was estimated to be 97 kg (wet weight). Solea senegalensis total consumption in nursery A was estimated to be 103 kg, while in nursery B it was 528 kg. Total prey biomass estimated for nursery A was 300 tonnes, while for nursery B it was 58 tonnes. This suggests that food is not a limiting

  19. Performance Assessment of Bi-Directional Knotless Tissue-Closure Devices in Juvenile Chinook Salmon Surgically Implanted with Acoustic Transmitters, 2009 - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Woodley, Christa M.; Wagner, Katie A.; Bryson, Amanda J.

    2012-11-09

    The purpose of this report is to assess the performance of bi-directional knotless tissue-closure devices for use in tagging juvenile salmon. This study is part of an ongoing effort at Pacific Northwest National Laboratory (PNNL) to reduce unwanted effects of tags and tagging procedures on the survival and behavior of juvenile salmonids, by assessing and refining suturing techniques, suture materials, and tag burdens. The objective of this study was to compare the performance of the knotless (barbed) suture, using three different suture patterns (treatments: 6-point, Wide “N”, Wide “N” Knot), to the current method of suturing (MonocrylTM monofilament, discontinuous sutures with a 2×2×2×2 knot) used in monitoring and research programs with a novel antiseptic barrier on the wound (“Second Skin”).

  20. Evaluation of Juvenile Fish Bypass and Adult Fish Passage Facilities at Three-Mile Falls Dam; Umatilla River, Oregon, 1989 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Nigro, Anthony A.

    1990-09-01

    We report on our progress from October 1989 through September 1990 on evaluating juvenile fish bypass and adult fish passage facilities at Three Mile Falls Dam on the Umatilla River. The study is a cooperative effort by the Oregon Department of Fish and Wildlife (ODFW) and the Confederated Tribes of the Umatilla Indian Reservation (CTUIR). Study objectives addressed by ODFW and CTUIR are: (1) ODFW (Report A): Operate and evaluate the juvenile fish bypass system in the West Extension Irrigation District canal at Three Mile Falls Dam; and (2) CTUIR (Report 8): Examine the passage of adult salmonids at Three Mile Falls Dam. The study is part of a program to rehabilitate anadromous fish stocks in the Umatilla River Basin that includes restorations of coho salmon Oncorhynchus Wsutch and chinook salmon 0. tshawytscha and enhancement of summer steelhead 0. mytiss.