Juvenile salmonid use of freshwater emergent wetlands in the floodplain and its implications for conservation management

Science.gov (United States)

Henning, Julie A.; Gresswell, Robert E.; Fleming, Ian A.

2006-01-01

A recent trend of enhancing freshwater emergent wetlands for waterfowl and other wildlife has raised concern about the effects of such measures on juvenile salmonids. We undertook this study to quantify the degree and extent of juvenile Pacific salmon Oncorhynchus spp. utilization of enhanced and unenhanced emergent wetlands within the floodplain of the lower Chehalis River, Washington, and to determine the fate of the salmon using them. Enhanced emergent wetlands contained water control structures that provided an outlet for fish emigration and a longer hydroperiod for rearing than unenhanced wetlands. Age-0 and age-1 coho salmon O. kisutch were the most common salmonid at all sites, enhanced wetlands having significantly higher age-1 abundance than unenhanced wetlands that were a similar distance from the main-stem river. Yearling coho salmon benefited from rearing in two enhanced wetland habitats, where their specific growth rate and minimum estimates of survival (1.43%/d by weight and 30%; 1.37%/d and 57%) were comparable to those in other side-channel rearing studies. Dissolved oxygen concentrations decreased in emergent wetlands throughout the season and approached the limits lethal to juvenile salmon by May or June each year. Emigration patterns suggested that age-0 and age-1 coho salmon emigrated as habitat conditions declined. This observation was further supported by the results of an experimental release of coho salmon. Survival of fish utilizing emergent wetlands was dependent on movement to the river before water quality decreased or stranding occurred from wetland desiccation. Thus, our results suggest that enhancing freshwater wetlands via water control structures can benefit juvenile salmonids, at least in the short term, by providing conditions for greater growth, survival, and emigration.

Effect of Multiple Turbine Passage on Juvenile Snake River Salmonid Survival

International Nuclear Information System (INIS)

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

2005-01-01

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

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.

Migration depth and residence time of juvenile salmonids in the forebays of hydropower dams prior to passage through turbines or juvenile bypass systems: implications for turbine-passage survival.

Science.gov (United States)

Li, Xinya; Deng, Zhiqun D; Brown, Richard S; Fu, Tao; Martinez, Jayson J; McMichael, Geoffrey A; Skalski, John R; Townsend, Richard L; Trumbo, Bradly A; Ahmann, Martin L; Renholds, Jon F

2015-01-01

Little is known about the three-dimensional depth distributions in rivers of individually marked fish that are in close proximity to hydropower facilities. Knowledge of the depth distributions of fish approaching dams can be used to understand how vulnerable fish are to injuries such as barotrauma as they pass through dams. To predict the possibility of barotrauma injury caused by pressure changes during turbine passage, it is necessary to understand fish behaviour relative to acclimation depth in dam forebays as they approach turbines. A guiding study was conducted using high-resolution three-dimensional tracking results of salmonids implanted with Juvenile Salmon Acoustic Telemetry System transmitters to investigate the depth distributions of subyearling and yearling Chinook salmon (Oncorhynchus tshawytscha) and juvenile steelhead (Oncorhynchus mykiss) passing two dams on the Snake River in Washington State. Multiple approaches were evaluated to describe the depth at which fish were acclimated, and statistical analyses were performed on large data sets extracted from ∼28 000 individually tagged fish during 2012 and 2013. Our study identified patterns of depth distributions of juvenile salmonids in forebays prior to passage through turbines or juvenile bypass systems. This research indicates that the median depth at which juvenile salmonids approached turbines ranged from 2.8 to 12.2 m, with the depths varying by species/life history, year, location (which dam) and diel period (between day and night). One of the most enlightening findings was the difference in dam passage associated with the diel period. The amount of time that turbine-passed fish spent in the immediate forebay prior to entering the powerhouse was much lower during the night than during the day. This research will allow scientists to understand turbine-passage survival better and enable them to assess more accurately the effects of dam passage on juvenile salmon survival.

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

DEFF Research Database (Denmark)

Krag, Ludvig Ahm

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...... in the mechanical effect, such as penetration depth of the ground gear of different trawl designs. Collecting bags are also mounted to the different sections of the trawl in pairs, one to collect the organisms that pass through the trawl meshes and one to collect the population. Standard selectivity analyses...

Significance of Selective Predation and Development of Prey Protection Measures for Juvenile Salmonids in the Columbia and Snake River Reservoirs: Annual Progress Report, February 1991-February 1992.

Energy Technology Data Exchange (ETDEWEB)

Poe, Thomas P.

1992-12-31

This document is the 1991 annual report of progress for the Bonneville Power Administration (BPA) research Project conducted by the US Fish and Wildlife Service (FWS). Our approach was to present the progress achieved during 1991 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. 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, 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.

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

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

Survival and growth rates of juvenile salmonids reared in lowland streams

Directory of Open Access Journals (Sweden)

Golski Janusz

2016-12-01

Full Text Available The aim of this study was to assess the efficiency of propagating juvenile trout, Salmo trutta L. in small lowland streams and to evaluate the impact of the environmental conditions in the streams on the juvenile fish. Brown trout (Salmo trutta fario and sea trout (Salmo trutta trutta early fry fed under controlled conditions were used to stock third-order lowland streams. During summer, fall, and spring catches, fry were counted, measured, and weighed. The following parameters were calculated using the data collected: fry stocking density (ind. m-2; survival; specific mortality rate (SMR; length range; mean specimen length; body weight; mean body weight; specific growth rate (SGR; body condition (Fulton’s index. The ichthyological studies were accompanied by simultaneous analyses of environmental conditions that were performed monthly, and benthic macroinvertebrates were sampled in spring and fall. No differences were observed in the biological parameters analyzed between sea trout and brown trout. Variability in environmental parameters such as temperature, oxygenation, conductivity, and stream width and depth were associated with differentiation in the biological parameters of the fry. The results clearly indicate that the considerable potential of small lowland streams for the propagation of salmonid juvenile stages is currently underexploited.

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.

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

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

Influence of riparian canopy on macroinvertebrate composition and food habits of juvenile salmonids in several Oregon streams.

Science.gov (United States)

William R. Meehan

1996-01-01

The community composition of macroinvertebrates and the feeding habits of juvenile salmonids were studied in eight Oregon streams. Benthic, drift, sticky trap, and water trap samples were taken over a 3-year period, along with stomach samples of the fish. Samples were taken in stream reaches with and without riparian canopy. Both main effects—fish diet versus...

Pathways of Barotrauma in Juvenile Salmonids Exposed to Simulated Hydroturbine Passage: Boyle’s Law vs. Henry’s Law

Energy Technology Data Exchange (ETDEWEB)

Brown, Richard S.; Pflugrath, Brett D.; Colotelo, Alison HA; Brauner, Colin J.; Carlson, Thomas J.; Deng, Zhiqun; Seaburg, Adam

2012-06-01

On their seaward migration, juvenile salmonids commonly pass hydroelectric dams. Fish passing by the turbine blade may experience rapid decompression, the severity of which can be highly variable and may result in a number of barotraumas. The mechanisms of these injuries can be due to expansion of existing bubbles or gases coming out of solution; governed by Boyle’s Law and Henry’s Law, respectively. This paper combines re-analysis of published data with new experiments to gain a better understanding of the mechanisms of injury and mortality for fish experiencing rapid decompression associated with hydroturbine passage. From these data it appears that the majority of decompression related injuries are due to the expansion of existing bubbles in the fish, particularly the expansion and rupture of the swim bladder. This information is particularly useful for fisheries managers and turbine manufacturers, demonstrating that reducing the rate of swim bladder ruptures by reducing the frequency of occurrence and severity of rapid decompression during hydroturbine passage could reduce the rates of injury and mortality for hydroturbine passed juvenile salmonids.

Approach, passage, and survival of juvenile salmonids at Little Goose Dam, Washington: Post-construction evaluation of a temporary spillway weir, 2009

Science.gov (United States)

Beeman, J.W.; Braatz, A.C.; Hansel, H.C.; Fielding, S.D.; Haner, P.V.; Hansen, G.S.; Shurtleff, D.J.; Sprando, J.M.; Rondorf, D.W.

2010-01-01

This report describes a study of dam passage and survival of radio-tagged juvenile salmonids after installation of a temporary spillway weir (TSW) at Little Goose Dam, Washington, in 2009. The purpose of the study was to document fish passage and survival when the dam was operated with the TSW in place. Spillway weirs are one of several methods used to improve downstream passage of juvenile salmonids. Each spillway weir design is based on the concept of providing an overflow weir with a depth more similar to the natural migration depth of juvenile salmonids than conventional spill bays. Little Goose Dam was the last of the four lower Snake River dams to have a spillway weir installed. This was the first year that some form of surface passage device was operating at all Snake River and Columbia River dams between Lewiston, Idaho, and the Columbia River estuary. The study design stipulated that a total of 30 percent of the river discharge would continuously be passed over the TSW and the conventional spill bays, and this percentage was achieved. The TSW also was to be operated at the 'low crest' elevation during the spring and the 'high crest' elevation during the summer, but the TSW was only operated at the low crest elevation during this study. Behavior, passage, and survival of spring and summer juvenile salmonid migrants passing through Little Goose Dam were examined using radio telemetry. Survival was estimated using the Route Specific Survival Model (RSSM) by releasing tagged fish near Central Ferry State Park 21 kilometers upstream of the dam and in the tailrace approximately 0.5 kilometer downstream of the dam. From April 18 to May 21, 2009, 1,520 yearling Chinook salmon (Oncorhynchus tshawytscha) and 1,517 juvenile steelhead (O. mykiss) were radio tagged and released. From June 6 to July 5, 2009, 4,251 subyearling Chinook salmon (O. tshawytscha) were radio tagged and released. Release dates of subyearling Chinook salmon were selected to avoid 'reservoir

Assessing survival of Mid-Columbia River released juvenile salmonids at McNary Dam, Washington, 2008-09

Science.gov (United States)

Evans, Scott D.; Walker, Christopher E.; Brewer, Scott J.; Adams, Noah S.

2010-01-01

Few studies have evaluated survival of juvenile salmon over long river reaches in the Columbia River and information regarding the survival of sockeye salmon at lower Columbia River dams is lacking. To address these information gaps, the U.S. Geological Survey was contracted by the U.S. Army Corps of Engineers to evaluate the possibility of using tagged fish released in the Mid-Columbia River to assess passage and survival at and downstream of McNary Dam. Using the acoustic telemetry systems already in place for a passage and survival study at McNary Dam, fish released from the tailraces of Wells, Rocky Reach, Rock Island, Wanapum, and Priest Rapids Dams were detected at McNary Dam and at the subsequent downstream arrays. These data were used to generate route-specific survival probabilities using single-release models from fish released in the Mid-Columbia River. We document trends in passage and survival probabilities at McNary Dam for yearling Chinook and sockeye salmon and juvenile steelhead released during studies in the Mid-Columbia River. Trends in the survival and passage of these juvenile salmonid species are presented and discussed. However, comparisons made across years and between study groups are not possible because of differences in the source of the test fish, the type of acoustic tags used, the absence of the use of passive integrated transponder tags in some of the release groups, differences in tagging and release protocols, annual differences in dam operations and configurations, differences in how the survival models were constructed (that is, number of routes that could be estimated given the number of fish detected), and the number and length of reaches included in the analysis (downstream reach length and arrays). Despite these differences, the data we present offer a unique opportunity to examine the migration behavior and survival of a group of fish that otherwise would not be studied. This is particularly true for sockeye salmon because

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

International Nuclear Information System (INIS)

Poe, T.P.

1994-01-01

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

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

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.

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.

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

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

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.

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.

Relationship of otolith strontium-to-calcium ratios and salinity: Experimental validation for juvenile salmonids

Science.gov (United States)

Zimmerman, C.E.

2005-01-01

Analysis of otolith strontium (Sr) or strontium-to-calcium (Sr:Ca) ratios provides a powerful tool to reconstruct the chronology of migration among salinity environments for diadromous salmonids. Although use of this method has been validated by examination of known individuals and translocation experiments, it has never been validated under controlled experimental conditions. In this study, incorporation of otolith Sr was tested across a range of salinities and resulting levels of ambient Sr and Ca concentrations in juvenile chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), sockeye salmon (Oncorhynchus nerka), rainbow trout (Oncorhynchus rnykiss), and Arctic char (Salvelinus alpinus). Experimental water was mixed, using stream water and seawater as end members, to create experimental salinities of 0.1, 6.3, 12.7, 18.6, 25.5, and 33.0 psu. Otolith Sr and Sr:Ca ratios were significantly related to salinity for all species (r2 range: 0.80-0.91) but provide only enough predictive resolution to discriminate among fresh water, brackish water, and saltwater residency. These results validate the use of otolith Sr:Ca ratios to broadly discriminate salinity histories encountered by salmonids but highlight the need for further research concerning the influence of osmoregulation and physiological changes associated with smoking on otolith microchemistry.

Rates of consumption of juvenile salmonids and alternative prey fish by northern squawfish, walleyes, smallmouth bass, and channel catfish in John Day Reservoir, Columbia River

International Nuclear Information System (INIS)

Vigg, S.; Poe, T.P.; Prendergast, L.A.; Hansel, H.C.

1991-01-01

Adult northern squawfish Ptychocheilus oregonesis, walleyes Stizostedion vitreum, smallmouth bass Micropterus dolomieu, and channel catfish Ictalurus punctatus were sampled from four regions of John Day Reservoir from April to August 1983-1986 to quantify their consumption of 13 species of prey fish, particularly seaward-migrating juvenile Pacific salmon and steelhead (Oncorhynchus spp.). Consumption rates were estimated from field data on stomach contents and digestion rate relations determined in previous investigations. For each predator, consumption rates varied by reservoir area, month, time of day, and predator size or age. The greatest daily consumption of salmonids by northern squawfish and channel catfish occurred in the upper end of the reservoir below McNary Dam. Greatest daily predation by walleyes and smallmouth bass occurred in the middle and lower reservoir. Consumption rates of all predators were highest in July, concurrent with maximum temperature and abundance of juvenile salmonids. Feeding by the predators tended to peak after dawn and near midnight. Northern squawfish below McNary Dam exhibited this pattern, but fed mainly in the morning hours down-reservoir. The daily ration of total prey fish was highest for northern squawfish over 451 mm fork length, for walleyes 201-250 mm, for smallmouth bass 176-200 mm, and for channel catfish 401-450 mm. Averaged over all predator sizes and sampling months (April-August), the total daily ration (fish plus other prey) of smallmouth bass was about twice that of channel catfish, northern squawfish, and walleyes. However, northern squawfish was clearly the major predator on juvenile salmonids

A multi-year analysis of spillway survival for juvenile salmonids as a function of spill bay operations at McNary Dam, Washington and Oregon, 2004-09

Science.gov (United States)

Adams, Noah S.; Hansel, Hal C.; Perry, Russell W.; Evans, Scott D.

2012-01-01

We analyzed 6 years (2004-09) of passage and survival data collected at McNary Dam to examine how spill bay operations affect survival of juvenile salmonids passing through the spillway at McNary Dam. We also examined the relations between spill bay operations and survival through the juvenile fish bypass in an attempt to determine if survival through the bypass is influenced by spill bay operations. We used a Cormack-Jolly-Seber release-recapture model (CJS model) to determine how the survival of juvenile salmonids passing through McNary Dam relates to spill bay operations. Results of these analyses, while not designed to yield predictive models, can be used to help develop dam-operation strategies that optimize juvenile salmonid survival. For example, increasing total discharge typically had a positive effect on both spillway and bypass survival for all species except sockeye salmon (Oncorhynchus nerka). Likewise, an increase in spill bay discharge improved spillway survival for yearling Chinook salmon (Oncorhynchus tshawytscha), and an increase in spillway discharge positively affected spillway survival for juvenile steelhead (Oncorhynchus mykiss). The strong linear relation between increased spill and increased survival indicates that increasing the amount of water through the spillway is one strategy that could be used to improve spillway survival for yearling Chinook salmon and juvenile steelhead. However, increased spill did not improve spillway survival for subyearling Chinook salmon and sockeye salmon. Our results indicate that a uniform spill pattern would provide the highest spillway survival and bypass survival for subyearling Chinook salmon. Conversely, a predominantly south spill pattern provided the highest spillway survival for yearling Chinook salmon and juvenile steelhead. Although spill pattern was not a factor for spillway survival of sockeye salmon, spill bay operations that optimize passage through the north and south spill bays maximized

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.

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.

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...

Juvenile Salmonid Metrics - 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...

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

Criteria for sustainable fisheries on juveniles illustrated for Mediterranean hake: control the juvenile harvest, and safeguard spawning refugia to rebuild population fecundity

Directory of Open Access Journals (Sweden)

John F. Caddy

2015-09-01

Full Text Available The paper provides a broad overview of issues relevant to management of fisheries for juvenile fish in contrast to the many stock assessments following Beverton and Holt’s (1957 approach for rational exploitation of mature fishes. A perspective on assessing these fisheries is illustrated for juvenile European hake, Merluccius merluccius, in the northwestern Mediterranean. Here, a constant natural mortality (M assumption is incorrect, as is the assumption that high fecundities are necessarily adequate for stock replacement. The high Ms-at-age for juveniles generated by the reciprocal model are shown to be a logical counterpart to the high fecundity of hake. Charnov’s criterion of intergenerational reproductive replacement is used to test for a sustainable population, analogous to a limit reference point warning of the dangers of overfishing beyond population replacement. Once peak mortality rates of age 2 hake exceed F(2=1.1-1.2, which is currently the case, reproductive replacement may be at risk. Adult exploitation by inshore trawls is low, and maturing hake surviving the fine-mesh trawl fishery migrate offshore with a reduced vulnerability to fine-mesh gears. Early research suggested that rough bottom near the shelf edge once formed a refugium protecting offshore spawners from trawling, and led to abundant recruitment of juveniles nearer shore. It may not do so if offshore fishing effort by reinforced bottom trawls, gill nets and longlines is uncontrolled. Restoring offshore refugia to protect spawners and controlling peak fishing mortality of juveniles would be a precautionary strategy aimed at restoring previous levels of recruitment to the small-mesh trawl fishery.

Juvenile Salmonid Necropsy 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...

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...

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...

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...

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).

The impact of the Sea Empress oil spill on the abundance of juvenile migratory salmonids in West Wales

International Nuclear Information System (INIS)

Roberts, D.E.; Jones, F.H.; Wyatt, R.J.; Milner, N.J.

1998-01-01

No counting facilities for adult salmonids were operational in the rivers draining into the area of coast affected by the Sea Empress oil spill. There were therefore no direct means of determining any impact on the numbers of returning salmon and sea trout. However, a measure of salmon and trout fry abundance before and after (1997) the spill may provide evidence of an impact; on recruitment and abundance of adults. Approximately 10 years historical fry data were available from 53 sites on the Tywi and 41 sites on the Taf, as part of the Welsh Region Juvenile Salmonid Monitoring Programme (RJSMP). An assessment was undertaken by the Water Research Centre on the design of the survey and appropriate data analysis. Analysed data included: River Tywi salmon and trout fry densities 1985-1996, compared to 1997 and Teifi control 1986-1997. River Taf salmon and trout fry densities 1986-1996, compared to 1997 and Teifi control 1986-1997. The abundance of salmon and trout fry in 1997 were similar to previous years suggesting the Sea Empress oil spill did not have a major impact on recruitment. However, it is not possible to conclude unequivocally that returning salmon and sea trout were not affected by the spill. (author)

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

International Nuclear Information System (INIS)

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.

2005-01-01

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 ∼7% of total project discharge), (2) create a gradual increase in water velocity approaching the surface flow bypass (ideally, acceleration 3 m/s) to entrain the subject juvenile

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

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.

System-wide significance of predation on juvenile salmonids in Columbia and Snake River reservoirs and evaluation of predation control measures. Annual report 1993

International Nuclear Information System (INIS)

Gadomski, D.M.; Poe, T.P.

1994-01-01

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

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

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.

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

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

Survival estimates for the passage of juvenile salmonids through Snake River dams and reservoirs, 1996. Annual report

International Nuclear Information System (INIS)

Smith, S.G.; Muir, W.D.; Hockersmith, E.E.; Achord, S.; Eppard, M.B.; Ruehle, T.E.; Williams, J.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

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.

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

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).

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

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.

Developing a predation index and evaluating ways to reduce salmonid losses to predation in the Columbia River basin

International Nuclear Information System (INIS)

Nigro, A.A.

1990-12-01

We report our results of studies to develop a predation index and evaluate ways to reduce juvenile salmonid losses to predation in the Columbia River Basin. Study objectives of each were: develop an index to estimate predation losses of juvenile salmonids (Oncorhynchus spp) in reservoirs throughout the Columbia River Basin, describe the relationships among predator-caused mortality of juvenile salmonids and physical and biological variables, examine the feasibility of developing bounty, commercial or recreational fisheries on northern squawfish (Ptychocheilus oregonensis) and develop a plan to evaluate the efficacy of predator control fisheries; determine the economic feasibility of developing bounty and commercial fisheries for northern squawfish, assist ODFW with evaluating the economic feasibility of recreational fisheries for northern squawfish and assess the economic feasibility of utilizing northern squawfish, carp (Cyprinus carpio) and suckers (Castostomus spp) in multispecies fisheries; evaluate commercial technology of various fishing methods for harvesting northern squawfish in Columbia River reservoirs and field test the effectiveness of selected harvesting systems, holding facilities and transportation systems; and modify the existing Columbia River Ecosystem Model (CREM) to include processes necessary to evaluate effects of removing northern squawfish on their population size structure and abundance, document the ecological processes, mathematical equations and computer (FORTRAN) programming of the revised version of CREM and conduct systematic analyses of various predator removal scenarios, using revised CREM to generate the simulations. Individual reports are indexed separately

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...... and acoustic research surveys. Horizontal distribution maps for the 2001–2010 cohorts of juvenile cod are further generated by applying a statistical log-Gaussian Cox process model to the standard trawl survey data. The analyses indicate size-dependent horizontal and distinct vertical and diurnal distribution...... in deep sea localities down to a 100 m depth and at oxygen concentrations between 2–4 ml O2.l−1. The vertical, diurnally stratified and repeated trawling and hydroacoustic target strength-depth distributions obtained from the special surveys show juvenile cod concentrations in frontal zone water layers...

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.

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

The design and analysis of salmonid tagging studies in the Columbia River. Volume 7: Monte-Carlo comparison of confidence internal procedures for estimating survival in a release-recapture study, with applications to Snake River salmonids

International Nuclear Information System (INIS)

Lowther, A.B.; Skalski, J.

1996-06-01

Confidence intervals for survival probabilities between hydroelectric facilities of migrating juvenile salmonids can be computed from the output of the SURPH software developed at the Center for Quantitative Science at the University of Washington. These intervals have been constructed using the estimate of the survival probability, its associated standard error, and assuming the estimate is normally distributed. In order to test the validity and performance of this procedure, two additional confidence interval procedures for estimating survival probabilities were tested and compared using simulated mark-recapture data. Intervals were constructed using normal probability theory, using a percentile-based empirical bootstrap algorithm, and using the profile likelihood concept. Performance of each method was assessed for a variety of initial conditions (release sizes, survival probabilities, detection probabilities). These initial conditions were chosen to encompass the range of parameter values seen in the 1993 and 1994 Snake River juvenile salmonid survival studies. The comparisons among the three estimation methods included average interval width, interval symmetry, and interval coverage

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.

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

The energetic consequences of habitat structure for forest stream salmonids.

Science.gov (United States)

Naman, Sean M; Rosenfeld, Jordan S; Kiffney, Peter M; Richardson, John S

2018-05-08

1.Increasing habitat availability (i.e. habitat suitable for occupancy) is often assumed to elevate the abundance or production of mobile consumers; however, this relationship is often nonlinear (threshold or unimodal). Identifying the mechanisms underlying these nonlinearities is essential for predicting the ecological impacts of habitat change, yet the functional forms and ultimate causation of consumer-habitat relationships are often poorly understood. 2.Nonlinear effects of habitat on animal abundance may manifest through physical constraints on foraging that restrict consumers from accessing their resources. Subsequent spatial incongruence between consumers and resources should lead to unimodal or saturating effects of habitat availability on consumer production if increasing the area of habitat suitable for consumer occupancy comes at the expense of habitats that generate resources. However, the shape of this relationship could be sensitive to cross-ecosystem prey subsidies, which may be unrelated to recipient habitat structure and result in more linear habitat effects on consumer production. 3.We investigated habitat-productivity relationships for juveniles of stream-rearing Pacific salmon and trout (Oncorhynchus spp.), which typically forage in low-velocity pool habitats, while their prey (drifting benthic invertebrates) are produced upstream in high-velocity riffles. However, juvenile salmonids also consume subsidies of terrestrial invertebrates that may be independent of pool-riffle structure. 4.We measured salmonid biomass production in 13 experimental enclosures each containing a downstream pool and upstream riffle, spanning a gradient of relative pool area (14-80% pool). Increasing pool relative to riffle habitat area decreased prey abundance, leading to a nonlinear saturating effect on fish production. We then used bioenergetics model simulations to examine how the relationship between pool area and salmonid biomass is affected by varying levels of

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

Deep Trawl Dataset

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Otter trawl (36' Yankee and 4-seam net deepwater gear) catches from mid-Atlantic slope and canyons at 200 - 800 m depth. Deep-sea (200-800 m depth) flat otter trawls...

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,...

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

Science.gov (United States)

Johnson, James H.; McKenna, James E.

2015-01-01

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

78 FR 9024 - Sea Turtle Conservation; Shrimp Trawling Requirements

Science.gov (United States)

2013-02-07

... restriction and require all skimmer trawls, pusher-head trawls, and wing nets (butterfly trawls) rigged for... purposes of this notice, skimmer trawls, pusher-head trawls, and wing nets (butterfly trawls) will be... trawls, pusher-head trawls, and wing nets (butterfly trawls) in the Gulf of Mexico to use TEDs in their...

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.

Microplastic sampling with the AVANI trawl compared to two neuston trawls in the Bay of Bengal and South Pacific.

Science.gov (United States)

Eriksen, Marcus; Liboiron, Max; Kiessling, Tim; Charron, Louis; Alling, Abigail; Lebreton, Laurent; Richards, Heather; Roth, Barent; Ory, Nicolas C; Hidalgo-Ruz, Valeria; Meerhoff, Erika; Box, Carolynn; Cummins, Anna; Thiel, Martin

2018-01-01

Many typical neuston trawls can only be used during relatively calm sea states and slow tow speeds. During two expeditions to the Bay of Bengal and the eastern South Pacific we investigated whether the new, high-speed AVANI trawl (All-purpose Velocity Accelerated Net Instrument) collects similar amounts and types of microplastics as two established scientific trawl designs, the manta trawl and the DiSalvo neuston net. Using a 335 μm net, the AVANI trawl can collect microplastics from the sea surface at speeds up to 8 knots as it "skis" across the surface, whereas the manta and DiSalvo neuston trawls must be towed slowly in a less turbulent sea state and often represent shorter tow lengths. Generally, the AVANI trawl collected a greater numerical abundance and weight of plastic particles in most size classes and debris types than the manta trawl and DiSalvo neuston net, likely because these trawls only skim the surface layer while the AVANI trawl, moving vertically in a random fashion, collects a "deeper" sample, capturing the few plastics that float slightly lower in the water column. However, the samples did not differ enough that results were significantly affected, suggesting that studies done with these different trawls are comparable. The advantage of the AVANI trawl over traditional research trawls is that it allows for collection on vessels underway at high speeds and during long transits, allowing for a nearly continuous sampling effort over long distances. As local surface currents make sea surface abundance widely heterogeneous, widely spaced short-tow trawls, such as the manta and DiSalvo trawls, can catch or miss hotspots or meso-scale variability of microplastic accumulations, whereas the AVANI trawl, if utilized for back-to-back tows of intermediate distances (5-10 km), can bridge variable wind conditions and debris concentrations potentially reducing variance and provide a greater resolution of spatial distribution. Copyright © 2017 Elsevier Ltd

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

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,...

Predation by northern squawfish on live and dead juvenile chinook salmon

International Nuclear Information System (INIS)

Gadomski, D.M.; Hall-Griswold, J.A.

1992-01-01

Northern squawfish Ptychocheilus oregonensis is a major predator of juvenile salmonids Oncorhynchus spp. migrating downstream through the Columbia River. High predation rates occur just below dams. If northern squawfish selectively consume salmonids killed or injured during dam passage, previous estimates of predation mortality may be too high. We conducted laboratory experiments that indicate northern squawfish prefer dead juvenile chinook salmon O. tshawytscha over live individuals. When equal numbers of dead and live chinook salmon were offered to northern squawfish maintained on a natural photoperiod (15 h light: 9 h darkness), significantly more (P < 0.05) dead than live fish were consumed, both in 1,400-L circular tanks and in an 11,300-L raceway (62% and 79% of prey consumed were dead, respectively). When dead and live juvenile chinook salmon were provided in proportions more similar to those below dams (20% dead, 80% live), northern squawfish still selected for dead prey (36% of fish consumed were dead). In additional experiments, northern squawfish were offered a proportion of 20% dead juvenile chinook salmon during 4-h periods of either light or darkness. The predators were much more selective for dead chinook salmon during bright light (88% of fish consumed were dead) than during darkness (31% were dead)

PELOLOSAN IKAN KURISI (Nemipterus japonicus MELALUI JUVENILE AND TRASH EXLUDER DEVICES PADA JARING ARAD

Directory of Open Access Journals (Sweden)

Hufiadi Hufiadi

2016-06-01

Full Text Available Permasalahan utama pada perikanan jaring arad adalah banyaknya jumlah hasil tangkap sampingan berukuran kecil yang belum layak tangkap. Dalam upaya untuk mengurangi tangkapan ikan muda yang belum layak tangkap telah dilakukan observasi dan ujicoba operasi penangkapan melalui penggunaan perangkat juvenile and trash exluder devices pada alat tangkap jaring arad yang dioperasikan nelayan di Pekalongan. Perangkat juvenile and trash exluder devices yang digunakan dibedakan pada ukuran jarak antar kisi, yaitu 10,0; 17,5; dan 25,4 mm. Analisis selektivitas kisi menggunakan model kurva logistik dengan bantuan solver pada Microsoft Excel. Hasil penelitian menunjukkan bahwa penggunaan juvenile and trash exluder devices pada jaring arad dapat meloloskan ikan kurisi (Nemipterus spp. berukuran kecil. Ukuran jarak antar kisi 25,4 mm mempunyai selektivitas yang paling baik terhadap ikan kurisi berdasarkan atas ukuran panjang baku dan jarak antar kisi 17,5 mm mempunyai selektivitas paling baik berdasarkan atas ukuran lingkar tubuh ikan kurisi.   The serius problem on bottom mini trawl has the large number caught of bycatch caught especially for juvenile and trash fish. Improvement to reduce catches of juvenile was conducted through observation and experimental fishing using juvenile and trash exluder devices of mini bottom trawl in Pekalongan. The juvenile and trash excluder devices (juvenile and trash exluder devices in the experimental fishing with different space bar of the juvenile and trash exluder devices i.e. 10.0; 17.5; and 25.4 mm. The selectivity analysis of logistic curve by using solver on Microsoft Excel was applied. The results showed that juvenile and trash excluder devices might reduce catches of threadfin breams juvenile. Where as 25.4 space bar had the best selectivity based on the size of threadfin breams fork length and 17.5 mm space bar had the best selectivity based on the size of threadfin breams body girth.

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.

Spatial and temporal heterogeneity of infectious hematopoietic necrosis virus in Pacific Northwest salmonids

Science.gov (United States)

Breyta, Rachel; Black, Allison; Kaufman, John; Kurath, Gael

2016-01-01

The aquatic rhaboviral pathogen infectious hematopoietic necrosis virus (IHNV) causes acute disease in juvenile fish of a number of populations of Pacific salmonid species. Heavily managed in both marine and freshwater environments, these fish species are cultured during the juvenile stage in freshwater conservation hatcheries, where IHNV is one of the top three infectious diseases that cause serious morbidity and mortality. Therefore, a comprehensive study of viral genetic surveillance data representing 2590 field isolates collected between 1958 and 2014 was conducted to determine the spatial and temporal patterns of IHNV in the Pacific Northwest of the contiguous United States. Prevalence of infection varied over time, fluctuating over a rough 5–7 year cycle. The genetic analysis revealed numerous subgroups of IHNV, each of which exhibited spatial heterogeneity. Within all subgroups, dominant genetic types were apparent, though the temporal patterns of emergence of these types varied among subgroups. Finally, the affinity or fidelity of subgroups to specific host species also varied, where UC subgroup viruses exhibited a more generalist profile and all other subgroups exhibited a specialist profile. These complex patterns are likely synergistically driven by numerous ecological, pathobiological, and anthropogenic factors. Since only a few anthropogenic factors are candidates for managed intervention aimed at improving the health of threatened or endangered salmonid fish populations, determining the relative impact of these factors is a high priority for future studies.

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

Improving the size- and species selectivity of cod (Gadus morhua) in demersal mixed-species trawl fisheries

DEFF Research Database (Denmark)

Krag, Ludvig Ahm

have been published in scientific journals and Paper 3 has been submitted to Fisheries Research. This review will take a broader perspective and will examine the capturing process, which is the basis for the selection process. Moreover, it discusses the existing methods and knowledge in the fields...... different species, including cod, are caught together. Demersal trawling is the predominant fishing method in Denmark, as measured by both catch value and volume. Demersal trawls also account for the highest discard rates of juvenile fish, including cod. The focus of this work was on improving......, and openings. The results show that the morphology-based simulations of size selectivity of cod can be used to explain a large part of both the within-haul and the between-haul variations previously reported from sea trials. The method can further predict the selection parameters (L50 and SR) for cod...

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

St Andrews Bay, Florida, Juvenile Reeffish Survey from 2002-07-05 to 2015-08-13 (NCEI Accession 0156994)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains Excel and CSV files containing fish length of Juvenile Reeffish. Trawls were made during the summer months in shallow seagrass beds to monitor...

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

Bottom trawl assessment of Lake Ontario prey fishes

Science.gov (United States)

Weidel, Brian C.; Connerton, Michael J.; Holden, Jeremy

2018-01-01

Managing Lake Ontario fisheries in an ecosystem-context requires prey fish community and population data. Since 1978, multiple annual bottom trawl surveys have quantified prey fish dynamics to inform management relative to published Fish Community Objectives. In 2017, two whole-lake surveys collected 341 bottom trawls (spring: 204, fall: 137), at depths from 8-225m, and captured 751,350 fish from 29 species. Alewife were 90% of the total fish catch while Deepwater Sculpin, Round Goby, and Rainbow Smelt comprised the majority of the remaining total catch (3.8, 3.1, and 1.1% respectively). The adult Alewife abundance index for US waters increased in 2017 relative to 2016, however the index for Canadian waters declined. Adult Alewife condition, assessed by the predicted weight of a 165 mm fish (6.5 inches), declined in 2017 from record high values observed in spring 2016. Spring 2017 Alewife condition was slightly less than the 10-year average, but the fall value was well below the 10-year average, likely due to increased Age-1 Alewife abundance. The Age-1 Alewife abundance index was the highest observed in 40 years, and 8-times higher than the previous year. The Age-1 index estimates Alewife reproductive success the preceding year. The warm summer and winter of 2016 likely contributed to the large year class. In contrast the relatively cool 2017 spring and cold winter may result in a lower than average 2017 year class. Abundance indices for Rainbow Smelt, Cisco, and Emerald Shiner either declined or remained at low levels in 2017. Pelagic prey fish diversity continues to be low since a single species, Alewife, dominates the catch. Deepwater Sculpin were the most abundant benthic prey fish in 2017 because Round Goby abundance declined sharply from 2016. Slimy Sculpin density continued to decline and the 2017 biomass index for US waters was the lowest ever observed. Prior to Round Goby proliferation, juvenile Slimy Sculpin comprised ~10% of the Slimy Sculpin catch, but

Integer-valued trawl processes

DEFF Research Database (Denmark)

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

2014-01-01

the probabilistic properties of such processes in detail and, in addition, study volatility modulation and multivariate extensions within the new modelling framework. Moreover, we describe how the parameters of a trawl process can be estimated and obtain promising estimation results in our simulation study. Finally......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...

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...

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...

Effect of commercially available egg cures on the survival of juvenile salmonids.

Directory of Open Access Journals (Sweden)

Shaun Clements

Full Text Available There is some concern that incidental consumption of eggs cured with commercially available cures for the purpose of sport fishing causes mortality in juvenile salmon. We evaluated this by feeding juvenile spring Chinook (Oncorhynchus tshawytscha and steelhead (O. mykiss with eggs cured with one of five commercially available cures. We observed significant levels of mortality in both pre-smolts and smolts. Depending on the experiment, 2, 3, or 4 of the cures were associated with mortality. Mortality tended to be higher in the smolts than in the parr, but there was no clear species effect. The majority of mortality occurred within the first 10 d of feeding. Removal of sodium sulfite from the cure significantly reduced the level of mortality. Soaking the eggs prior to feeding did not reduce mortality. We observed a clear relationship between the amount of cured egg consumed each day and the survival time. We conclude that consumption of eggs cured with sodium sulfite has the potential to cause mortality in juvenile steelhead and Chinook salmon in the wild.

Effect of commercially available egg cures on the survival of juvenile salmonids

Science.gov (United States)

Clements, S.; Chitwood, R.; Schreck, C.B.

2011-01-01

There is some concern that incidental consumption of eggs cured with commercially available cures for the purpose of sport fishing causes mortality in juvenile salmon. We evaluated this by feeding juvenile spring Chinook (Oncorhynchus tshawytscha) and steelhead (O. mykiss) with eggs cured with one of five commercially available cures. We observed significant levels of mortality in both pre-smolts and smolts. Depending on the experiment, 2, 3, or 4 of the cures were associated with mortality. Mortality tended to be higher in the smolts than in the parr, but there was no clear species effect. The majority of mortality occurred within the first 10 d of feeding. Removal of sodium sulfite from the cure significantly reduced the level of mortality. Soaking the eggs prior to feeding did not reduce mortality. We observed a clear relationship between the amount of cured egg consumed each day and the survival time. We conclude that consumption of eggs cured with sodium sulfite has the potential to cause mortality in juvenile steelhead and Chinook salmon in the wild.

Occurrence and significance of atypical Aeromonas salmonicida in non-salmonid and salmonid fish species : A review

DEFF Research Database (Denmark)

Wiklund, T.; Dalsgaard, Inger

1998-01-01

, 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...... information is available about the ecology, spread and survival of atypical strains in water. The commonly used therapeutic methods for the control of diseases in farmed fish caused by atypical A. salmonicida are generally effective against the atypical strains. Resistance to different antibiotics...

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.

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

Science.gov (United States)

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

2009-01-01

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

Impacts of Columbia River discharge on salmonid habitat: 2. Changes in shallow-water habitat

Science.gov (United States)

Kukulka, Tobias; Jay, David A.

2003-09-01

This is the second part of an investigation that analyzes human alteration of shallow-water habitat (SWH) available to juvenile salmonids in the tidal Lower Columbia River. Part 2 develops a one-dimensional, subtidal river stage model that explains ˜90% of the stage variance in the tidal river. This model and the tidal model developed in part 1 [, 2003] uncouple the nonlinear interaction of river tides and river stage by referring both to external forcing by river discharge, ocean tides, and atmospheric pressure. Applying the two models, daily high-water levels were predicted for a reach from rkm-50 to rkm-90 during 1974 to 1998, the period of contemporary management. Predicted water levels were related to the bathymetry and topography to determine the changes in shallow-water habitat area (SWHA) caused by flood control dikes and altered flow management. Model results suggest that diking and a >40% reduction of peak flows have reduced SWHA by ˜62% during the crucial spring freshet period during which juvenile salmon use of SWHA is maximal. Taken individually, diking and flow cycle alteration reduced spring freshet SWHA by 52% and 29%, respectively. SWHA has been both displaced to lower elevations and modified in its character because tidal range has increased. Our models of these processes are economical for the very long simulations (seasons to centuries) needed to understand historic changes and climate impacts on SWH. Through analysis of the nonlinear processes controlling surface elevation in a tidal river, we have identified some of the mechanisms that link freshwater discharge to SWH and salmonid survival.

FRD Trawl Database

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Fish captured in trawls by the SWFSC Fisheries Resources Division during surveys for coastal pelagic species. Most tows were targeted for sardine using a Nordic...

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

-specific quotas. The toplesstrawl design was developed to improve species-specific selectivity in such fisheries. In a topless trawl,the foot rope is located more forward than the headline to allow fish to escape upwards, whereas theheadline is located in front in traditional trawl designs. In this study we...... Atlantic, topless trawls have been introducedas legal cod-selective trawl designs. However, this study demonstrates that identical gear modificationsmade to similar trawls of different sizes and used in the same fishery can lead to different results....

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

International Nuclear Information System (INIS)

Zimmerman, B.C.; Duke, B.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

50 CFR 660.337 - Trawl rationalization program - data collection requirements.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Trawl rationalization program - data... COAST STATES West Coast Groundfish Fisheries § 660.337 Trawl rationalization program - data collection... guarantee that they will qualify for quota share under a future trawl rationalization program. The following...

77 FR 38266 - Sea Turtle Conservation; Shrimp Trawling Requirements; Public Hearing

Science.gov (United States)

2012-06-27

... withdraw the alternative tow time restriction and require all skimmer trawls, pusher-head trawls, and wing nets (butterfly trawls) rigged for fishing to use turtle excluder devices (TEDs) in their nets, which...

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.

The footprint of bottom trawling in European waters

NARCIS (Netherlands)

Eigaard, Ole R.; Bastardie, Francois; Hintzen, Niels T.; Buhl-Mortensen, Lene; Buhl-Mortensen, Pål; Catarino, Rui; Dinesen, Grete E.; Egekvist, Josefine; Fock, Heino O.; Geitner, Kerstin; Gerritsen, Hans D.; González, Manuel Marín; Jonsson, Patrik; Kavadas, Stefanos; Laffargue, Pascal; Lundy, Mathieu; Gonzalez-Mirelis, Genoveva; Nielsen, J.R.; Papadopoulou, Nadia; Posen, Paulette E.; Pulcinella, Jacopo; Russo, Tommaso; Sala, Antonello; Silva, Cristina; Smith, Christopher J.; Vanelslander, Bart; Rijnsdorp, Adriaan D.

2017-01-01

Mapping trawling pressure on the benthic habitats is needed as background to support an ecosystem approach to fisheries management. The extent and intensity of bottom trawling on the European continental shelf (0-1000 m) was analysed from logbook statistics and vessel monitoring system data for

Analyses of potential factors affecting survival of juvenile salmonids volitionally passing through turbines at McNary and John Day Dams, Columbia River

Science.gov (United States)

Beeman, John; Hansel, Hal; Perry, Russell; Hockersmith, Eric; Sandford, Ben

2011-01-01

This report describes analyses of data from radio- or acoustic-tagged juvenile salmonids passing through hydro-dam turbines to determine factors affecting fish survival. The data were collected during a series of studies designed to estimate passage and survival probabilities at McNary (2002-09) and John Day (2002-03) Dams on the Columbia River during controlled experiments of structures or operations at spillways. Relatively few tagged fish passed turbines in any single study, but sample sizes generally were adequate for our analyses when data were combined from studies using common methods over a series of years. We used information-theoretic methods to evaluate biological, operational, and group covariates by creating models fitting linear (all covariates) or curvilinear (operational covariates only) functions to the data. Biological covariates included tag burden, weight, and water temperature; operational covariates included spill percentage, total discharge, hydraulic head, and turbine unit discharge; and group covariates included year, treatment, and photoperiod. Several interactions between the variables also were considered. Support of covariates by the data was assessed by comparing the Akaike Information Criterion of competing models. The analyses were conducted because there was a lack of information about factors affecting survival of fish passing turbines volitionally and the data were available from past studies. The depth of acclimation, tag size relative to fish size (tag burden), turbine unit discharge, and area of entry into the turbine intake have been shown to affect turbine passage survival of juvenile salmonids in other studies. This study indicates that turbine passage survival of the study fish was primarily affected by biological covariates rather than operational covariates. A negative effect of tag burden was strongly supported in data from yearling Chinook salmon at John Day and McNary dams, but not for subyearling Chinook salmon or

Species-specific gradients of juvenile fish density and size in pelagic areas of temperate reservoirs

Czech Academy of Sciences Publication Activity Database

Jůza, Tomáš; Ricard, Daniel; Blabolil, Petr; Čech, Martin; Draštík, Vladislav; Frouzová, Jaroslava; Muška, Milan; Peterka, Jiří; Prchalová, Marie; Říha, Milan; Sajdlová, Zuzana; Šmejkal, Marek; Tušer, Michal; Vašek, Mojmír; Vejřík, Lukáš; Kubečka, Jan

2015-01-01

Roč. 762, č. 1 (2015), s. 169-181 ISSN 0018-8158 R&D Projects: GA MŠk(CZ) EE2.3.20.0204; GA MŠk(CZ) EE2.3.30.0032; GA MŠk(CZ) 7F14316 Institutional support: RVO:60077344 Keywords : trawling * juvenile density * horizontal distribution * vertical distribution * tributary area Subject RIV: EH - Ecology, Behaviour Impact factor: 2.051, year: 2015

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.

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.

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

Optimisation of trawl energy efficiency under fishing effort constraint

OpenAIRE

Priour, Daniel; Khaled, Ramez

2009-01-01

Trawls energy efficiency is greatly affected by the drag, as well as by the swept area. The drag results in an increase of the energy consumption and the sweeping influences the catch. Methods of optimisation of the trawl design have been developed in order to reduce the volume of carburant per kg of caught fish and consequently the drag per swept area of the trawl. Based on a finite element method model for flexible netting structures, the tool modifies step by step a reference design. For e...

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

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

Directory of Open Access Journals (Sweden)

Simon J Allen

Full Text Available 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

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,...

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...

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.

Summer Bottom Trawl Survey

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Sampling the coastal waters of the Gulf of Maine using the Northeast Fishery Science Center standardized bottom trawl has been problematic due to large areas of hard...

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....

Estimating the size of juvenile fish populations in southeastern coastal-plain estuaries

International Nuclear Information System (INIS)

Kjelson, M.A.

1977-01-01

Understanding the ecological significance of man's activities upon fishery resources requires information on the size of affected fish stocks. The objective of this paper is to provide information to evaluate and plan sampling programs designed to obtain accurate and precise estimates of fish abundance. Nursery habitats, as marsh--tidal creeks and submerged grass beds, offer the optimal conditions for estimating natural mortality rates for young-of-the-year fish in Atlantic and Gulf of Mexico coast estuaries. The area-density method of abundance estimation using quantitative gears is more feasible than either mark-recapture or direct-count techniques. The blockage method provides the most accurate estimates, while encircling devices enable highly mobile species found in open water to be captured. Drop nets and lift nets allow samples to be taken in obstructed sites, but trawls and seines are the most economical gears. Replicate samples are necessary to improve the precision of density estimates, while evaluation and use of gear-catch efficiencies is feasible and required to improve the accuracy of density estimates. Coefficients of variation for replicate trawl samples range from 50 to 150 percent, while catch efficiencies for both trawls and seines for many juvenile fishes range from approximately 30 to 70 percent

Some quantitative indicators of postovulatory aging and its effect on larval and juvenile development of Atlantic salmon (Salmo salar).

Science.gov (United States)

Mommens, Maren; Storset, Arne; Babiak, Igor

2015-07-01

Modern out-of-season egg production in Atlantic salmon (Salmo salar) increases the risk of postovulatory aging (POA) of oocytes. Postovulatory aging is known to influence oocyte quality in salmonids, but reliable tests for POA are lacking in Atlantic salmon egg production. To address this problem, we have collected oocytes from the same 20 Atlantic salmon females sequentially in approximately 1-week intervals, from the start of ovulation until 28 days postovulation (dpo), to determine the effect of natural retention of matured oocytes in body coelomic cavity on further performance of embryos and juveniles produced from those oocytes. Also, we investigated oocyte water hardening and several coelomic fluid parameters as potential quantitative indicators of POA. Oocyte quality decreased significantly from 22 dpo onward, as inferred from decrease in fertilization success and survival of embryos, alevins, and juveniles and increase in alevin and juvenile deformity rates. The occurrence of head deformities was significantly related to postovulatory age of oocytes. Coelomic fluid pH decreased significantly at 28 dpo and correlated positively with fertilization rates (r = 0.45), normal eyed embryo rates (r = 0.67), and alevin relative survival rates (r = 0.63) and negatively correlated with total alevin deformity rates (r = -0.59). Oocyte weight gain at 60 minutes decreased significantly at 28 dpo and correlated negatively with total alevin deformities and the occurrence of cranial nodules (r = -0.99). Generally, quality of ovulated oocytes remained stable for the first 2 weeks after ovulation. Later on, POA negatively influenced Atlantic salmon embryo, alevin, and juvenile performance. For the first time, we show a long-term effect of POA on salmonid juvenile performance. Standardized pH measurements of coelomic fluid could potentially improve embryo and juvenile production by identifying low-quality oocytes at an early stage during the production. Copyright © 2015

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...

Detection and quantification of Renibacterium salmoninarum DNA in salmonid tissues by real-time quantitative polymerase chain reaction analysis

Science.gov (United States)

Chase, D.M.; Elliott, D.G.; Pascho, R.J.

2006-01-01

Renibacterium salmoninarum is an important salmonid pathogen that is difficult to culture. We developed and assessed a real-time, quantitative, polymerase chain reaction (qPCR) assay for the detection and enumeration of R. salmoninarum. The qPCR is based on TaqMan technology and amplifies a 69-base pair (bp) region of the gene encoding the major soluble antigen (MSA) of R. salmoninarum. The qPCR assay consistently detected as few as 5 R. salmoninarum cells per reaction in kidney tissue. The specificity of the qPCR was confirmed by testing the DNA extracts from a panel of microorganisms that were either common fish pathogens or reported to cause false-positive reactions in the enzyme-linked immunosorbent assay (ELISA). Kidney samples from 38 juvenile Chinook salmon (Oncorhynchus tshawytscha) in a naturally infected population were examined by real-time qPCR, a nested PCR, and ELISA, and prevalences of R. salmoninarum detected were 71, 66, and 71%, respectively. The qPCR should be a valuable tool for evaluating the R. salmoninarum infection status of salmonids.

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...

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.

An epidemiological model of virus transmission in salmonid fishes of the Columbia River Basin

Science.gov (United States)

Ferguson, Paige F. B.; Breyta, Rachel; Brito, Ilana L.; Kurath, Gael; LaDeau, Shannon L.

2018-01-01

cohort-sites experienced self-exposure by infected juvenile fish, this transmission route had the greatest probability of infection (0.22). Increased testing and/or determining whether transmission can occur from cohort-sites without testing records (e.g., determining there was no testing record because there were no fish at the cohort-site) are expected to improve inference about infection probabilities. Increased use of secure water supplies and continued use of biosecurity protocols may reduce IHNV transmission from adult fish and juvenile fish within the site, respectively, to juvenile salmonids at hatcheries. Models and conclusions from this study are potentially relevant to understanding the relative importance of transmission routes for other important aquatic pathogens in salmonids, including the agents of bacterial kidney disease and coldwater disease, and the basic approach may be useful for other pathogens and hosts in other geographic regions.

Global analysis of depletion and recovery of seabed biota after bottom trawling disturbance.

Science.gov (United States)

Hiddink, Jan Geert; Jennings, Simon; Sciberras, Marija; Szostek, Claire L; Hughes, Kathryn M; Ellis, Nick; Rijnsdorp, Adriaan D; McConnaughey, Robert A; Mazor, Tessa; Hilborn, Ray; Collie, Jeremy S; Pitcher, C Roland; Amoroso, Ricardo O; Parma, Ana M; Suuronen, Petri; Kaiser, Michel J

2017-08-01

Bottom trawling is the most widespread human activity affecting seabed habitats. Here, we collate all available data for experimental and comparative studies of trawling impacts on whole communities of seabed macroinvertebrates on sedimentary habitats and develop widely applicable methods to estimate depletion and recovery rates of biota after trawling. Depletion of biota and trawl penetration into the seabed are highly correlated. Otter trawls caused the least depletion, removing 6% of biota per pass and penetrating the seabed on average down to 2.4 cm, whereas hydraulic dredges caused the most depletion, removing 41% of biota and penetrating the seabed on average 16.1 cm. Median recovery times posttrawling (from 50 to 95% of unimpacted biomass) ranged between 1.9 and 6.4 y. By accounting for the effects of penetration depth, environmental variation, and uncertainty, the models explained much of the variability of depletion and recovery estimates from single studies. Coupled with large-scale, high-resolution maps of trawling frequency and habitat, our estimates of depletion and recovery rates enable the assessment of trawling impacts on unprecedented spatial scales.

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

Culture of salmonid fishes

National Research Council Canada - National Science Library

Stickney, Robert R

1991-01-01

.... In recognition of the growing concern that aquaculture development has the potential to negatively impact the natural environment, a chapter on controversies surrounding salmonid culture has been included...

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.

Trapping and transportation of adult and juvenile salmon in the lower Umatilla River in northeast Oregon, 1996-1997. Umatilla River Basin Trap and Haul Program. Annual progress report, October 1996 - September 1997

International Nuclear Information System (INIS)

Zimmerman, B.; Duke, B.B.

1997-09-01

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 30, 1996 to August 26, 1997. A total of 2,477 summer steelhead (Oncorhynchus mykiss); 646 adult, 80 jack, and 606 subjack fall chinook (O. tshawytscha); 618 adult and 24 jack coho (O. kisutch); and 2,194 adult and four jack spring chinook (O. tshawytscha) were collected. All fish were trapped at the east bank facility. Of the fish collected, 22 summer steelhead; 18 adult and two jack fall chinook; five adult coho; and 407 adult and three jack spring chinook were hauled upstream from Threemile Dam. There were 2,245 summer steelhead; 70 adult, 51 jack and 520 subjack fall chinook; 593 adult and 24 jack coho; and 1,130 adult spring chinook released at Threemile Dam I In addition, 110 summer steelhead; 551 adult and 25 jack fall chinook; and 600 adult spring chinook were collected for broodstock. 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 canal was open for a total of 210 days between December 16, 1996 and July 30, 1997. During that period, fish were bypassed back to the river 175 days and were trapped on 35 days, An estimated 1,675 pounds of juvenile fish were transported from Westland to the Umatilla River boat ramp (RM 0.5), Approximately 80% of the juveniles transported were salmonids, No steelhead kelts were hauled from Westland this year. The Threemile Dam west bank juvenile bypass was operated from October 4 to November 1, 1996 and from March 26 to July 7, 1997. The juvenile trap was not operated this year. 6 refs., 6 figs., 6 tabs

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.

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

Directory of Open Access Journals (Sweden)

Shengmao Zhang

Full Text Available 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.

A simple model that identifies potential effects of sea-level rise on estuarine and estuary-ecotone habitat locations for salmonids in Oregon, USA.

Science.gov (United States)

Flitcroft, Rebecca; Burnett, Kelly; Christiansen, Kelly

2013-07-01

Diadromous aquatic species that cross a diverse range of habitats (including marine, estuarine, and freshwater) face different effects of climate change in each environment. One such group of species is the anadromous Pacific salmon (Oncorhynchus spp.). Studies of the potential effects of climate change on salmonids have focused on both marine and freshwater environments. Access to a variety of estuarine habitat has been shown to enhance juvenile life-history diversity, thereby contributing to the resilience of many salmonid species. Our study is focused on the effect of sea-level rise on the availability, complexity, and distribution of estuarine, and low-freshwater habitat for Chinook salmon (Oncorhynchus tshawytscha), steelhead (anadromous O. mykiss), and coho salmon (O. kisutch) along the Oregon Coast under future climate change scenarios. Using LiDAR, we modeled the geomorphologies of five Oregon estuaries and estimated a contour associated with the current mean high tide. Contour intervals at 1- and 2-m increments above the current mean high tide were generated, and changes in the estuary morphology were assessed. Because our analysis relied on digital data, we compared three types of digital data in one estuary to assess the utility of different data sets in predicting the changes in estuary shape. For each salmonid species, changes in the amount and complexity of estuarine edge habitats varied by estuary. The simple modeling approach we applied can also be used to identify areas that may be most amenable to pre-emptive restoration actions to mitigate or enhance salmonid habitat under future climatic conditions.

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...

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.

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

Marine AS. The project will examine krill escape mortality from the codend during a full scale field experiment, model size selectivity and escape mortality in codends including different designs and assess the size selectivity in the trawl body forward of the codend. Based on end results from the preceding...... examinations we will be able to predict size selectivity and escape mortality from the entire trawl body with the appurtenant mortality for different trawl designs......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...

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

Functional Annotation of All Salmonid Genomes (FAASG): an international initiative supporting future salmonid research, conservation and aquaculture.

Science.gov (United States)

Macqueen, Daniel J; Primmer, Craig R; Houston, Ross D; Nowak, Barbara F; Bernatchez, Louis; Bergseth, Steinar; Davidson, William S; Gallardo-Escárate, Cristian; Goldammer, Tom; Guiguen, Yann; Iturra, Patricia; Kijas, James W; Koop, Ben F; Lien, Sigbjørn; Maass, Alejandro; Martin, Samuel A M; McGinnity, Philip; Montecino, Martin; Naish, Kerry A; Nichols, Krista M; Ólafsson, Kristinn; Omholt, Stig W; Palti, Yniv; Plastow, Graham S; Rexroad, Caird E; Rise, Matthew L; Ritchie, Rachael J; Sandve, Simen R; Schulte, Patricia M; Tello, Alfredo; Vidal, Rodrigo; Vik, Jon Olav; Wargelius, Anna; Yáñez, José Manuel

2017-06-27

We describe an emerging initiative - the 'Functional Annotation of All Salmonid Genomes' (FAASG), which will leverage the extensive trait diversity that has evolved since a whole genome duplication event in the salmonid ancestor, to develop an integrative understanding of the functional genomic basis of phenotypic variation. The outcomes of FAASG will have diverse applications, ranging from improved understanding of genome evolution, to improving the efficiency and sustainability of aquaculture production, supporting the future of fundamental and applied research in an iconic fish lineage of major societal importance.

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

Science.gov (United States)

Abookire, Alisa A.; Piatt, John 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.

Behaviour of fish by-catch in the mouth of a crustacean trawl.

Science.gov (United States)

Queirolo, D; Gaete, E; Montenegro, I; Soriguer, M C; Erzini, K

2012-06-01

The behaviour of fish by-catch was recorded and characterized by in situ observations in the mouth of a crustacean trawl using an underwater camera system with artificial light, at depths between 106 and 461 m, along the central coast of Chile. The groups or species studied were rattails (family Macrouridae), Chilean hake Merluccius gayi gayi, sharks (orders Carcharhiniformes and Squaliformes), skates (family Rajidae), flatfishes (genus Hippoglossina) and small benthopelagic and demersal fishes (orders Osmeriformes, Stomiiformes, Gadiformes, Ophidiiformes and Perciformes). The fish behaviour was categorized in terms of (1) position in the water column, (2) initial orientation with respect to the trawl, (3) locomotion and (4) swimming speed with respect to the trawl. Rattails, sharks, skates and flatfishes were passive in response to the trawl and showed similar behavioural patterns, with most fishes observed sitting or touching the bottom with no swimming or other activity. Merluccius gayi gayi was the most active species, displaying a wide combination of behavioural responses when the trawl approached. This species showed several behavioural patterns, mainly characterized by swimming forward at variable speed. A fraction of small bentho-pelagic and demersal fishes also showed an active behaviour but always at lower speed than the trawl. The species-specific differences in behaviour in the mouth of the trawl suggest that improvements at the level of the footrope can be made to reduce by-catch, especially of passive species. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

Fish Individual-based Numerical Simulator (FINS): A particle-based model of juvenile salmonid movement and dissolved gas exposure history in the Columbia River Basin

International Nuclear Information System (INIS)

Scheibe, Timothy D.; Richmond, Marshall C.

2002-01-01

This paper describes a numerical model of juvenile salmonid migration in the Columbia and Snake Rivers. The model, called the Fish Individual-based Numerical Simulator or FINS, employs a discrete, particle-based approach to simulate the migration and history of exposure to dissolved gases of individual fish. FINS is linked to a two-dimensional (vertically-averaged) hydrodynamic simulator that quantifies local water velocity, temperature, and dissolved gas levels as a function of river flow rates and dam operations. Simulated gas exposure histories can be input to biological mortality models to predict the effects of various river configurations on fish injury and mortality due to dissolved gas supersaturation. Therefore, FINS serves as a critical linkage between hydrodynamic models of the river system and models of biological impacts. FINS was parameterized and validated based on observations of individual fish movements collected using radiotelemetry methods during 1997 and 1998 . A quasi-inverse approach was used to decouple fish swimming movements from advection with the local water velocity, allowing inference of time series of non-advective displacements of individual fish from the radiotelemetry data. Statistical analyses of these displacements are presented, and confirm that strong temporal correlation of fish swimming behavior persists in some cases over several hours. A correlated random-walk model was employed to simulate the observed migration behavior, and parameters of the model were estimated that lead to close correspondence between predictions and observations

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

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...... found with both trawling and eDNA, while three families were found only with eDNA and two families were found only with trawling. Key commercial fish species for Greenland were the most abundant species in both eDNA reads and biomass catch, and interpolation of eDNA abundances between sampling sites...

75 FR 13081 - Fisheries off West Coast States; Pacific Coast Groundfish Fishery; Trawl Rationalization Program

Science.gov (United States)

2010-03-18

... West Coast States; Pacific Coast Groundfish Fishery; Trawl Rationalization Program AGENCY: National... proposed Trawl Rationalization Program. We are interested in feedback concerning proposed regulations to... Pacific Fishery Management Council (Council) has been developing a trawl rationalization program that...

Development of a systemwide predator control program: Stepwise implementation of a predator index, predator control fisheries, and evaluation plan in the Columbia River basin (Northern Squawfish Management Program). Section 1: Implementation; Annual report 1995

International Nuclear Information System (INIS)

Young, F.R.

1997-04-01

The authors report their results from the fifth year of a basinwide program to harvest northern squawfish (Ptychocheilus oregonensis) in an effort to reduce mortality due to northern squawfish predation on juvenile salmonids during their emigration from natal streams to the ocean. Earlier work in the Columbia River Basin suggested predation by northern squawfish on juvenile salmonids may account for most of the 10--20% mortality juvenile salmonids experience in each of eight Columbia and Snake River reservoirs. Modeling simulations based on work in John Day Reservoir from 1982 through 1988 indicated that if predator-sized northern squawfish were exploited at a 10--20% rate, the resulting restructuring of their population could reduce their predation on juvenile salmonids by 50%

Epibenthic diversity and productivity on a heavily trawled Barents Sea bank (Tromsøflaket

Directory of Open Access Journals (Sweden)

Monika Kędra

2017-04-01

Full Text Available Shallow Arctic banks have been observed to harbour rich communities of epifaunal organisms, but have not been well-studied with respect to composition or function due to sampling challenges. In order to determine how these banks function in the Barents Sea ecosystem, we used a combination of video and trawl/dredge sampling at several locations on a heavily trawled bank, Tromsøflaket – located at the southwestern entrance to the Barents Sea. We describe components of the benthic community, and calculate secondary production of dominant epifaunal organisms. Forty-six epibenthic taxa were identified, and sponges were a significant part of the surveyed benthic communities. There were differences in diversity and production among areas, mainly related to the intensity of trawling activities. Gamma was the most diverse and productive area, with highest species abundance and biomass. Trawled areas had considerably lower species numbers, and significant differences in epifaunal abundance and biomass were found between all trawled and untrawled areas. Trawling seems to have an impact on the sponge communities: mean individual poriferan biomass was higher in untrawled areas, and, although poriferans were observed in areas subjected to more intensive trawling, they were at least five times less frequent than in untrawled areas.

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

The Kattegat in the inner Danish waters has been trawled for at least 80 yr, but so far only few attempts have been made to quantify the trawl effort, its spatial distribution and its potential ecological impact on the benthic fauna. GIS-analyses of VMS-data from trawling in the Kattegat by both ...

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

77 FR 66577 - Fisheries Off West Coast States; Pacific Coast Groundfish Fishery; Trawl Rationalization Program...

Science.gov (United States)

2012-11-06

...-XC165 Fisheries Off West Coast States; Pacific Coast Groundfish Fishery; Trawl Rationalization Program... implemented as part of the trawl rationalization program. FOR FURTHER INFORMATION CONTACT: Jamie Goen, phone..., NMFS implemented a trawl rationalization program, a catch share program, for the Pacific coast...

FLEXSELECT: counter-herding device to reduce bycatch in crustacean trawl fisheries

DEFF Research Database (Denmark)

Melli, Valentina; Karlsen, Junita Diana; Feekings, Jordan P.

2018-01-01

FLEXSELECT is a simple counter-herding device which aims at reducing the bycatch of fish by scaring them away from the trawl path without affecting the catches of the target species. FLEXSELECT was tested in the Norway lobster (Nephrops norvegicus) directed trawl fishery, as this includes bycatch...

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

Science.gov (United States)

Hinz, Hilmar; Moranta, Joan; Balestrini, Stephen; Sciberras, Marija; Pantin, Julia R; Monnington, James; Zalewski, Alex; Kaiser, Michel J; Sköld, Mattias; Jonsson, Patrik; Bastardie, Francois; Hiddink, Jan Geert

2017-07-24

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 may both negatively and positively influence the quantity and quality of food available. Using δ 13 C and δ 15 N we investigated potential diet changes of three commercially exploited species across trawling gradients in the Kattegat (plaice, dab and Norway lobster (Nephrops)) and the Irish Sea (Nephrops). In the Kattegat, trawling affected primarily the biomass of benthic consumers, lowering competition. Nephrops showed significant positive relationships for δ 13 C and a domed relationship for δ 15 N with trawling. In the Irish Sea, intense trawling had a negative effect on benthic prey. δ 13 C and δ 15 N thus showed the inverse relationships to those observed in the Kattegat. Plaice from the Kattegat, showed a significant relationship with trawling intensity for δ 13 C, but not for δ 15 N. No relationship was found for dab. Changes of δ 13 C and δ 15 N correlated with changes in condition of species. The results show that the removal of demersal competitors and benthos by trawling can change the diets of commercial species, ultimately affecting their body condition.

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.

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

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...

Deep-Sea Mega-Epibenthic Assemblages from the SW Portuguese Margin (NE Atlantic Subjected to Bottom-Trawling Fisheries

Directory of Open Access Journals (Sweden)

Sofia P. Ramalho

2017-11-01

Full Text Available Bottom-trawling fisheries are a common threat to the health of continental margins worldwide. Together with numerous environmental and biological processes, physical disturbance induced by trawlers can largely shape the benthic habitats and their associated assemblages. At the SW Portuguese Margin, crustacean bottom trawlers have exploited deep-sea habitats for a few decades, but its effects on the benthic biodiversity are practically unknown. During the spring-summer of 2013 and 2014, several Remotely Operated Vehicle (ROV video transects were used to investigate mega-epibenthic abundance, composition, and diversity in soft-sediment areas subjected to varying trawling pressures off Sines and Setúbal (200–800 m. Differences in mega-epibenthic assemblages were linked with environmental changes (depth, grain size, primary productivity and trawling disturbance. The effect of trawling was assessed between segments with similar habitat characteristics, i.e., muddy-sand bottoms between 300 and 500 m. Areas subjected to intensive trawling pressure showed a generally flattened seabed, with abundant recent trawl marks (up to 3 scars.100 m−1, indicating that the seabed physical integrity was compromised. Significant negative correlations were detected between various mega-epibenthic diversity indices [S, H′, and ET(20] and trawling pressure (h.cell−1.y−1. Furthermore, the distinct mega-epibenthic assemblages and absence of several sessile erect morphospecies at both low and highly disturbed locations by trawling off Sines, namely all seapen morphospecies found in non-trawled areas, demonstrates the negative influence of trawling fisheries on the benthic component of the study area. Also, low dissimilarity between assemblages from the main fishing grounds and the adjacent low-disturbance locations, suggests that the potentially negative influence of trawling can extend beyond the targeted areas (e.g., by the plumes of re-suspended sediments. The

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.

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 it i...

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.

Influences of forest and rangeland management on salmonid fishes and their habitats

National Research Council Canada - National Science Library

Meehan, William R

1991-01-01

Contents : Stream ecosystems - Salmonid distributions and life histories - Habitat requirements of salmonids in streams - Natural processes - Timber harvesting, silvicultrue and watershed processes - Forest...

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.

Impacts of Bottom Trawling and Litter on the Seabed in Norwegian Waters

Directory of Open Access Journals (Sweden)

Pål Buhl-Mortensen

2018-02-01

Full Text Available Bottom trawling and seabed littering are two serious threats to seabed integrity. We present an overview of the distribution of seabed litter and bottom trawling in Norwegian waters (the Norwegian Sea and the southern Barents Sea. Vessel Monitoring System (VMS records and trawl marks (TM on the seabed were used as indicators of pressure and impact of bottom trawling, respectively. Estimates of TM density and litter abundance were based on analyses of seabed videos from 1,778 locations, surveyed during 23 cruises, part of the Norwegian seabed mapping programme MAREANO. The abundance and composition of litter and the density of TM varied with depth, and type of sediments and marine landscapes. Lost or discarded fishing gear (especially lines and nets, and plastics (soft and hard plastic and rubber were the dominant types of litter. The distribution of litter reflected the distribution of fishing intensity (density of VMS records and density of TM at a regional scale, with highest abundance close to the coast and in areas with high fishing intensity, indicated from the VMS data. However, at a local scale patterns were less clear. An explanation to this could be that litter is transported with currents and accumulates in troughs, canyons, and local depressions, rather than reflecting the fisheries footprints directly. Also, deliberate dumping of discarded fishing gear is likely to occur away from good fishing grounds. Extreme abundance of litter, observed close to the coast is probably caused by such discarded fishing gear, but the contribution from aggregated populations on land is also indicated from the types of litter observed. The density of trawl marks is a good indicator of physical impact in soft sediments where the trawl gear leaves clear traces, whereas on harder substrates the impacts on organisms is probably greater than indicated by the hardly visible marks. The effects of litter on benthic communities is poorly known, but large litter

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 retained...

Linking Forests and Fish: The Relationship Between Productivities of Salmonids and Forest Stands in Northern California

Science.gov (United States)

Wilzbach, P.; Frazey, S.

2005-05-01

Productivities of resident salmonid populations, upland, and riparian areas in 25 small watersheds of coastal northern California were estimated and compared to determine if: 1) upland site productivity predicted riparian site productivity; 2) either upland or riparian site productivity predicted salmonid productivity; and 3) other parameters explained more of the variance in salmonid productivity than upland or riparian site productivity. Salmonid productivity was indexed by total salmonid biomass, length of age 1 fish, and percent habitat saturation. Upland and riparian site productivities were estimated using site indices for redwood (Sequoia sempervirens) and red alder (Alnus rubra), respectively. Upland and riparian site indices were correlated, but neither factor contributed to the best approximating models of salmonid biomass or fish length at age one. Salmonid biomass was best described by a positive relationship with drainage area, and length at age was best described by a positive relationship with percent of riparian hardwoods. Percent habitat saturation was not well described by any of the models constructed. Lack of a relationship between upland conifer and salmonid productivity suggests that management of land for timber productivity and component streams for salmonid production in these sites will require separate, albeit integrated, strategies.

Configuring the Mesh Size, Side Taper and Wing Depth of Penaeid Trawls to Reduce Environmental Impacts

Science.gov (United States)

Broadhurst, Matt K.; Sterling, David J.; Millar, Russell B.

2014-01-01

The effects of reducing mesh size while concomitantly varying the side taper and wing depth of a generic penaeid-trawl body were investigated to improve engineering performance and minimize bycatch. Five trawl bodies (with the same codends) were tested across various environmental (e.g. depth and current) and biological (e.g. species and sizes) conditions. The first trawl body comprised 41-mm mesh and represented conventional designs (termed the ‘41 long deep-wing'), while the remaining trawl bodies were made from 32-mm mesh and differed only in their side tapers, and therefore length (i.e. 1N3B or ‘long’ and ∼28o to the tow direction vs 1N5B or ‘short’ and ∼35o) and wing depths (‘deep’–97 T vs ‘shallow’–60 T). There were incremental drag reductions (and therefore fuel savings – by up to 18 and 12% per h and ha trawled) associated with reducing twine area via either modification, and subsequently minimizing otter-board area in attempts to standardize spread. Side taper and wing depth had interactive and varied effects on species selectivity, but compared to the conventional 41 long deep-wing trawl, the 32 short shallow-wing trawl (i.e. the least twine area) reduced the total bycatch by 57% (attributed to more fish swimming forward and escaping). In most cases, all small-meshed trawls also caught more smaller school prawns Metapenaeus macleayi but to decrease this effect it should be possible to increase mesh size slightly, while still maintaining the above engineering benefits and species selectivity. The results support precisely optimizing mesh size as a precursor to any other anterior penaeid-trawl modifications designed to improve environmental performance. PMID:24911786

Status and trends of the Lake Huron deepwater demersal fish ommunity, 2008

Science.gov (United States)

Roseman, Edward F.; O'Brien, Timothy P.; Riley, Stephen C.; Farha, Steve A.; French, John R.

2009-01-01

The U.S.Geological Survey Great Lakes Science Center has conducted trawl surveys to assess annual changes in the deepwater demersal fish community of Lake Huron since 1973. Since 1992, surveys have been carried out using a 21 m wing trawl towed on-contour at depths ranging from 9 to 110 m on fixed transects. Sample sites include five ports in U.S. waters with less frequent sampling near Goderich, Ontario. The 2008 fall bottom trawl survey was carried out between October 24 and November 20, 2008 and sampled only the three northern U.S. ports at DeTour, Hammond Bay, and Alpena due to mechanical problems with the research vessel and prolonged periods of bad weather. Therefore, all data presented for 2008 are based on samples collected from these ports. Compared to previous years, alewife populations in Lake Huron remain at low levels after collapsing in 2004. Age-0 alewife density and biomass appears to have increased slightly but overall levels remain near the nadir observed in 2004. Density and biomass of adult and juvenile rainbow smelt showed a decrease from 2007 despite record-high abundance of juveniles observed in 2005, suggesting recruitment was low. Numbers of adult and juvenile bloater were low despite recent high year-classes. Abundances for most other prey species were similar to the low levels observed in 2005 - 2007. We captured one wild juvenile lake trout in 2008 representing the fifth consecutive year that wild lake trout were captured in the survey. Based on pairwise graphical comparisons and nonparametric correlation analyses, dynamics of prey abundance at the three northern ports followed lakewide trends since 1992. Density of benthic macroinvertebrates was at an all-time low in 2008 since sampling began in 2001. The decline in abundance was due to decreases in all taxonomic groups and a large reduction in recruitment of quagga mussels. Density of Diporeia at northern ports in 2008 was the lowest observed. Diporeia were found only at 73-m sites of

trawl codends for blue whiting (Micromesistius

African Journals Online (AJOL)

Administrator

2010-12-27

Dec 27, 2010 ... Page 1 ... landing size; PE, polyethylene; PA, polyamide; LSMTPC, large square mesh top panel codend; SR, selection range. taceans by traditional Mediterranean trawls in seasonal .... Size structure of the population indicated retaining (thin line), escaping. (broken line) and entering (thick line) from the ...

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.

Similar effects of bottom trawling and natural disturbance on composition and function of benthic communities across habitats

NARCIS (Netherlands)

Denderen, van Daniel; Bolam, Stefan G.; Hiddink, Jan Geert; Jennings, Simon; Kenny, Andrew; Rijnsdorp, Adriaan D.; Kooten, Van Tobias

2015-01-01

Bottom trawl fishing has widespread impacts on benthic habitats and communities. The benthic response to trawling seems to be smaller or absent in areas exposed to high natural disturbance, leading to the hypothesis that natural and trawl disturbance affect benthic communities in a similar way.

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...

Environmental DNA from Seawater Samples Correlate with Trawl Catches of Subarctic, Deepwater Fishes.

Directory of Open Access Journals (Sweden)

Philip Francis Thomsen

Full Text Available 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 found with both trawling and eDNA, while three families were found only with eDNA and two families were found only with trawling. Key commercial fish species for Greenland were the most abundant species in both eDNA reads and biomass catch, and interpolation of eDNA abundances between sampling sites showed good correspondence with catch sizes. Environmental DNA sequence reads from the fish assemblages correlated with biomass and abundance data obtained from trawling. Interestingly, the Greenland shark (Somniosus microcephalus showed high abundance of eDNA reads despite only a single specimen being caught, demonstrating the relevance of the eDNA approach for large species that can probably avoid bottom trawls in most cases. Quantitative detection of marine fish using eDNA remains to be tested further to ascertain whether this technique is able to yield credible results for routine application 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

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

Bycatch in 36 and 40 mm PA Turkish twin rigged beam trawl codends

African Journals Online (AJOL)

The Turkish twin rigged beam trawl which has two identical nets rigged side by side on the same beam targets mainly the Parapenaeus longirostris, although some bycatch fish species have also become target species. Thus, landings of the shrimp beam trawling fleet also include some commercially valuable fishes.

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...

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

The paper develops a biological-economic evaluation tool to analyse the consequences for trawl fishers of implementing more selective fishing technologies. This is done by merging a dynamic biological population model and an economic cost-benefit evaluation framework to describe the consequences...... 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...... 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 byratches of several species. Four different kinds of selectivity scenarios are evaluated in comparison...

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

The paper develops a biological-economic evaluation tool to analyse the consequences for trawl fishers of implementing more selective fishing technologies. This is done by merging a dynamic biological population model and an economic cost-benefit evaluation framework to describe the consequences...... 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...... 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...

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.

Quantity and biochemical composition of particulate organic matter in a highly trawled area (Thermaikos Gulf, Eastern Mediterranean Sea

Directory of Open Access Journals (Sweden)

Antonio Pusceddu

2015-11-01

Full Text Available Bottom trawling represents nowadays one of the most severe anthropogenic disturbances at sea, and determines large impacts on benthic communities and processes. Bottom trawling determines also local sediment resuspension and the effects of the injection of large amounts of surface sediments into the water column have been repeatedly investigated. Few studies have assessed the consequences of sediment resuspension caused by bottom trawling on the quantity, biochemical composition and bioavailability of suspended organic particles and how these eventually rival those exerted by natural storms. To provide insights on this poorly addressed issue, we investigated concentrations and biochemical composition of total and enzymatically digestible pools of particulate organic matter (POM in the Thermaikos Gulf (Mediterranean Sea under calm sea conditions, during intensive trawling activities, and after a severe storm. We show here that sediment resuspension caused by trawling can cause large effects on POM quantity, biochemical composition and bioavailability. Both during trawling and after the storm, the relative importance of the carbohydrate pools increased (in the upper water column and the total lipid concentrations decreased (in the intermediate and bottom layers when compared to values measured during calm conditions. These results would suggest that bottom trawling could inject in the upper water column POM pools more refractory in nature (e.g., carbohydrates than those present in calm or after-storm conditions. By contrast, we show also that the bioavailable fraction of biopolymeric C increased significantly during trawling in the upper water column of the shallowest stations and in the bottom water column layer of the deepest ones. These results provide evidence that bottom trawling can influence the overall trophic status of coastal waters, exerting effects similar or stronger than those caused by natural storms, though of variable amplitude

78 FR 40435 - Proposed Information Collection; Comment Request; Gulf of Alaska Trawl Fishery, Rationalization...

Science.gov (United States)

2013-07-05

... Collection; Comment Request; Gulf of Alaska Trawl Fishery, Rationalization Sociocultural Study AGENCY... management actions requiring equivalent information. Fisheries rationalization programs have an impact on... the implementation of a new, yet to be defined, rationalization program for the Gulf of Alaska trawl...

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.

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

pressure. 2. We assessed the impact of bottom trawling on the food availability, condition and stomach contents of three flatfishes and the Norway lobster in an area in the Kattegat hat is characterized by a steep commercial bottom-trawling gradient due to the establishment of an area closed to all....... This pattern was mirrored in both the condition and stomach contents of plaice and for long-rough dab. 4. No effect of trawling on dab prey and condition was found. Conversely, the condition of the main target species – Norway lobster – increased as its biomass decreased with increased trawling intensities. 5...

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...

75 FR 76400 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2010-12-08

... issues permits based on findings that such permits: (1) Are applied for in good faith; (2) if granted and... the summer ecology of juvenile salmonids in streams of the Lagunitas Creek (Marin County) and... study on the ecology of juvenile salmonids in Tomales Bay, and Pescadero Lagoon and their overall...

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...

Evaluation of juvenile salmonid bypass facilities and passage at water diversions on the lower Umatilla River. Final report

International Nuclear Information System (INIS)

Cameron, W.A.; Knapp, S.M.; Carmichael, R.W.

1997-07-01

Outdated juvenile and adult fish passage facilities were recently reconstructed at the five major irrigation dams on the lower Umatilla River, Oregon to meet National marine Fisheries Service (NMFS) design standards. Changes in design at juvenile fish bypass facilities included reduced mesh size on the rotating drum screens, larger screening area, a more oblique orientation of the drum screens to canal flow, improved screen seals, replacement of bypass portals with vertical slot bypass channels, and increased bypass pipe diameters. Weir-and-pool adult fish ladders and jump pools were replaced with vertical-slot ladders. From 1991--1995, they investigated injury and travel rate of juvenile fish moving through the facilities, and efficiency of screens in preventing fish entry into the canals. Water velocities in front of canal screens, at bypass channel entrances, and at ladder diffusers were measured to assess adherence to NMFS criteria and identify hydraulic patterns. Biological evaluations were conducted by releasing and recapturing marked yearling summer steelhead (Oncorhynchus mykiss), yearling spring chinook salmon (O. tshawytscha), and subyearling fall chinook salmon (O. tshawytscha) in varying locations within the fish passage facilities

78 FR 3848 - Fisheries Off West Coast States; Pacific Coast Groundfish Fishery; Trawl Rationalization Program...

Science.gov (United States)

2013-01-17

... Rationalization Program; Emergency Rule Extension AGENCY: National Marine Fisheries Service (NMFS), National... Coast Groundfish Fishery Trawl Rationalization Program (program) regulations. This emergency rule... trawl rationalization program. Background on this rule was provided in the proposed rule, published on...

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

Recovery of Seamount Precious Coral Beds From Heavy Trawling Disturbance with Links to Carbonate Chemistry Changes

Science.gov (United States)

Roark, E. B.; Baco-Taylor, A.; Morgan, N. B.; Shamberger, K.; Miller, K.; Brooks, J.

2016-12-01

Increasing anthropogenic impacts in the deep sea make studies of resilience and recovery time critical, with deep-sea hard-substrate habitats and large-scale disturbances having received little attention. Seamount hard-substrate habitats in particular are thought to have low resilience due to the slow growth rates and recruitment limitations of key structure-forming taxa. Seamounts of the far Northwestern Hawaiian Islands and Emperor Chain have had some of the heaviest trawl impacts in the world, from both fish and precious coral fisheries, and include sites that are still trawled and recovering ones that have been protected since establishment of the EEZ in 1977. To test the hypothesis of low resilience we compare these impacted seamounts to untrawled sites. We used the AUV Sentry in 2014 and 2015 to image nine features (three per "treatment") and analyze for substrate and visible megafauna. Sites in the "still trawled" treatment were characterized by extensive areas of bare substrate with abundant trawl scars. Sites in the "recovering" and "never trawled" locations had abundant megafauna in hard substrate areas. Initial comparisons of transects at 700m depth for three sites indicate that Yuryaku in the "still trawled" treatment had lower diversity and abundance of megafauna compared to the "recovering" and "never trawled" locations with a dominance of sea urchins. The "recovering" and "never trawled" sites were dominated by cnidarians, fishes, and echinoderms, but differed in dominant species, diversity, abundances and occurrence of dead coral skeletons. These preliminary results suggest that the recovering sites have not returned to a pre-impact community type in the 38 years since they were trawled. The megafauna distribution, in particular that of deep-sea corals, was compared to environmental water column variables at the study sites across the Northwestern Hawaiian Islands. Deep-sea corals with calcium carbonate skeletons were found living below the

The NSW Steam Trawl Fishery on the South-East Continental Shelf of Australia, 1915-1961

DEFF Research Database (Denmark)

Jacobsen, A. Lif Lund

2014-01-01

How was modern fishing methods, in the form of steam trawling, introduced in Australia? And what were the consequences for the fish stocks found on the South-East Continental Shelf? Through historical catch records and archival resources, the history of the NSW Steam Trawl Industry from 1915...... that flathead biomass on the South-East Continental shelf was permanently reduced. The study furthermore reveals how the trawl industry was influenced by government policy, market conditions, war and fishing effort with little understanding of the marine resources which they relied on....

Lost in translation? Multi-metric macrobenthos indicators and bottom trawling

DEFF Research Database (Denmark)

Gislason, Henrik; Bastardie, Francois; Dinesen, Grete E.

2017-01-01

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...... of individuals per sample (density), we expect species density and density to be positively correlated. This correlation was confirmed by a simulation model and by statistical analysis of the bottom samples in which log species density was highly significantly related to log density (r = 0.75, df = 144, p ...

trawl bycatch in the fishing grounds of Bus

African Journals Online (AJOL)

ajl yemi

2011-11-30

. Biol. 86: 1455-1462. Watson RA, Dredge MLC, Mayer DG (1990). Spatial and seasonal variation in demersal trawl fauna associated with a prawn fishery on the CentralGreat Barrier Reef, Australia. Aust. J. Mar. Freshw. Res.

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.

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

78 FR 75268 - Fisheries Off West Coast States; Pacific Coast Groundfish Fishery; Trawl Rationalization Program...

Science.gov (United States)

2013-12-11

... Rationalization Program; Cost Recovery AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... recovery program for the Pacific coast groundfish trawl rationalization program, as required by the...). Allocations to the limited entry trawl fleet for certain species were developed through a parallel process...

Assessment of native salmonids above Hells Canyon Dam, Idaho; 1998 annual progress report

International Nuclear Information System (INIS)

Meyer, Kevin A.

1999-01-01

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

77 FR 33717 - Endangered and Threatened Species; Take of Anadromous Fish

Science.gov (United States)

2012-06-07

... applied for in good faith; (2) if granted and exercised, would not operate to the disadvantage of the... public comment. Project 1 is a study on the summer ecology of juvenile salmonids in streams of the... is a study on the ecology of juvenile salmonids in Tomales Bay, Pescadero Lagoon, and the Eel River...

Distribution and abundance of juvenile demersal fishes in relation to summer hypoxia and other environmental variables in coastal Oregon, USA

Science.gov (United States)

Sobocinski, Kathryn L.; Ciannelli, Lorenzo; Wakefield, W. Waldo; Yergey, Matthew E.; Johnson-Colegrove, Angela

2018-05-01

The juvenile demersal fish assemblage along the Pacific Northwest coast has received little attention relative to adult life history stages since pioneering work in the 1970s. Increasing severity of hypoxia along the Oregon coast in recent years has prompted investigations into the response of biota in this region. We used summer data (2008-2013) from a beam trawl survey targeting juvenile demersal fishes in soft-bottom habitats along the Oregon coast to describe patterns of distribution and abundance at fixed sampling stations (from 30 m to 100 m depth). We relate the assemblage and abundance of the common species to environmental variables and analyze condition of recently settled fish (improve our understanding of this community, especially in light of changing environmental drivers such as decreasing pH, warming water, and episodic periods of low dissolved oxygen coinciding with settlement for many species.

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...

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.

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.T.

The present communication is a study on the impact of bottom trawling on the sediment characteristics along Veraval coast, which is the largest trawler port of India. Experimental bottom trawling was conducted from MFV Sagarkripa at five transects...

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”).

Development of a systemwide predator control program: Stepwise implementation of a predation index, predator control fisheries, and evaluation plan in the Columbia River Basin. Section 1: Implementation. Annual report 1994

International Nuclear Information System (INIS)

Willis, C.F.; Young, F.R.

1995-09-01

The authors report the results from the forth year of a basinwide program to harvest northern squawfish (Ptychocheilus oregonensis) in an effort to reduce mortality due to northern squawfish predation on juvenile salmonids during their emigration from natal streams to the ocean. Earlier work in the Columbia River Basin suggested predation by northern squawfish on juvenile salmonids may account for most of the 10--20% mortality juvenile salmonids experience in each of eight Columbia and Snake River reservoirs. Modeling simulations based on work in John Day Reservoir from 1982 through 1988 indicated it is not necessary to eradicate northern squawfish to substantially reduce predation-caused mortality of juvenile salmonids. Instead, if northern squawfish were exploited at a 10--20% rate, reductions in numbers of larger, older fish resulting in restructuring of their population could reduce their predation on juvenile salmonids by 50% or more. Consequently, the authors designed and tested a sport-reward angling fishery and a commercial longline fishery in the John Day pool in 1990. They also conducted an angling fishery in areas inaccessible to the public at four dams on the mainstem Columbia River and at Ice Harbor Dam on the Snake River. Based on the success of these limited efforts, they implemented three test fisheries on a multi-pool, or systemwide, scale in 1991--a tribal longline fishery above Bonneville Dam, a sport-reward fishery, and a dam-angling fishery

Development of a Systemwide Predator Control Program, Section I : Northern Squawfish Management Program Implementation, 1994 annual report.

Energy Technology Data Exchange (ETDEWEB)

Willis, Charles F. (S.P. Cramer and Associates, Inc., Gresham, OR); Young, Franklin R. (Columbia Basin Fish and Wildlife Authority, Portland, OR)

1995-09-01

The authors report the results from the forth year of a basinwide program to harvest northern squawfish (Ptychocheilus oregonensis) in an effort to reduce mortality due to northern squawfish predation on juvenile salmonids during their emigration from natal streams to the ocean. Earlier work in the Columbia River Basin suggested predation by northern squawfish on juvenile salmonids may account for most of the 10--20% mortality juvenile salmonids experience in each of eight Columbia and Snake River reservoirs. Modeling simulations based on work in John Day Reservoir from 1982 through 1988 indicated it is not necessary to eradicate northern squawfish to substantially reduce predation-caused mortality of juvenile salmonids. Instead, if northern squawfish were exploited at a 10--20% rate, reductions in numbers of larger, older fish resulting in restructuring of their population could reduce their predation on juvenile salmonids by 50% or more. Consequently, the authors designed and tested a sport-reward angling fishery and a commercial longline fishery in the John Day pool in 1990. They also conducted an angling fishery in areas inaccessible to the public at four dams on the mainstem Columbia River and at Ice Harbor Dam on the Snake River. Based on the success of these limited efforts, they implemented three test fisheries on a multi-pool, or systemwide, scale in 1991--a tribal longline fishery above Bonneville Dam, a sport-reward fishery, and a dam-angling fishery.

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 (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 than under severe hypoxia. These statistically significant trends demonstrate that the structuring influences of bottom trawling on deep-sea benthic communities can be observed even where communities are being shaped by strong environmental gradients.

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.

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

2018-03-01

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.

Precision in systematic trawl surveys as assessed from replicate ...

African Journals Online (AJOL)

Local variability was analysed as random noise, modelled and later reapplied ... The main statistical techniques applied were less susceptible to outlier catches ... be used to estimate the vessel factor when intercalibrating trawl survey vessels.

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

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......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...

Incorporating episodicity into estimates of Critical Loads for juvenile salmonids in Scottish streams

Directory of Open Access Journals (Sweden)

E. E. Bridcut

2004-01-01

Full Text Available Critical Load (CL methodology is currently used throughout Europe to assess the risks of ecological damage due to sulphur and nitrogen emissions. Critical acid neutralising capacity (ANCCRIT is used in CL estimates for freshwater systems as a surrogate for biological damage. Although UK CL maps presently use an ANC value of 0 μeq l-1, this value has been based largely on Norwegian lake studies, in which brown trout is chosen as a representative indicator organism. In this study, an ANC value specific for brown trout in Scottish streams was determined and issues were addressed such as salmon and trout sensitivity in streams, episodicity, afforestation and complicating factors such as dissolved organic carbon (DOC and labile aluminium (Al-L. Catchments with significant forest cover were selected to provide fishless sites and to provide catchment comparisons in unpolluted areas. Chemical factors were the primary determinant with land use a secondary determinant of the distribution of salmonid populations at the twenty-six study sites. ANC explained more variance in brown trout density than pH. The most significant index of episodicity was percent of time spent below an ANC of 0 μeq l-1. An ANCCRIT value of 39 μeq l-1 was obtained based on a 50% probability of brown trout occurrence. The use of this revised ANCCRIT value in the CL equation improved the relationship between trout status and exceedance of CLs. Uncertainties associated with variations in Al-L at any fixed ANCCRIT, particularly within forested catchments, and the role of DOC in modifying the toxicity of Al-L are discussed. Keywords: Critical Load, Critical acid neutralising capacity, brown trout, episodes, streams

The malleable gut microbiome of juvenile rainbow trout (Oncorhynchus mykiss): Diet-dependent shifts of bacterial community structures.

Science.gov (United States)

Michl, Stéphanie Céline; Ratten, Jenni-Marie; Beyer, Matt; Hasler, Mario; LaRoche, Julie; Schulz, Carsten

2017-01-01

Plant-derived protein sources are the most relevant substitutes for fishmeal in aquafeeds. Nevertheless, the effects of plant based diets on the intestinal microbiome especially of juvenile Rainbow trout (Oncorhynchus mykiss) are yet to be fully investigated. The present study demonstrates, based on 16S rDNA bacterial community profiling, that the intestinal microbiome of juvenile Rainbow trout is strongly affected by dietary plant protein inclusion levels. After first feeding of juveniles with either 0%, 50% or 97% of total dietary protein content derived from plants, statistically significant differences of the bacterial gut community for the three diet-types were detected, both at phylum and order level. The microbiome of juvenile fish consisted mainly of the phyla Proteobacteria, Firmicutes, Bacteroidetes, Fusobacteria and Actinobacteria, and thus fits the salmonid core microbiome suggested in previous studies. Dietary plant proteins significantly enhanced the relative abundance of the orders Lactobacillales, Bacillales and Pseudomonadales. Animal proteins in contrast significantly promoted Bacteroidales, Clostridiales, Vibrionales, Fusobacteriales and Alteromonadales. The overall alpha diversity significantly decreased with increasing plant protein inclusion levels and with age of experimental animals. In order to investigate permanent effects of the first feeding diet-type on the early development of the microbiome, a diet change was included in the study after 54 days, but no such effects could be detected. Instead, the microbiome of juvenile trout fry was highly dependent on the actual diet fed at the time of sampling.

Passage survival of juvenile steelhead, coho salmon, and Chinook salmon in Lake Scanewa and at Cowlitz Falls Dam, Cowlitz River, Washington, 2010–16

Science.gov (United States)

Liedtke, Theresa L.; Kock, Tobias J.; Hurst, William

2018-04-03

A multi-year evaluation was conducted during 2010–16 to evaluate passage survival of juvenile steelhead (Oncorhynchus mykiss), Chinook salmon (O. tshawytscha), and coho salmon (O. kisutch) in Lake Scanewa, and at Cowlitz Falls Dam in the upper Cowlitz River Basin, Washington. Reservoir passage survival was evaluated in 2010, 2011, and 2016, and included the tagging and release of 1,127 juvenile salmonids. Tagged fish were released directly into the Cowlitz and Cispus Rivers, 22.3 and 8.9 km, respectively, upstream of the reservoir, and were monitored as they moved downstream into, and through the reservoir. A single release-recapture survival model was used to analyze detection records and estimate reservoir passage survival, which was defined as successful passage from reservoir entry to arrival at Cowlitz Falls Dam. Tagged fish generally moved quickly downstream of the release sites and, on average, arrived in the dam forebay within 2 d of release. Median travel time from release to first detection at the dam ranged from 0.23 to 0.96 d for juvenile steelhead, from 0.15 to 1.11 d for juvenile coho salmon, and from 0.18 to 1.89 d for juvenile Chinook salmon. Minimum reservoir passage survival probabilities were 0.960 for steelhead, 0.855 for coho salmon and 0.900 for Chinook salmon.Dam passage survival was evaluated at the pilot-study level during 2013–16 and included the tagging and release of 2,512 juvenile salmonids. Juvenile Chinook salmon were evaluated during 2013–14, and juvenile steelhead and coho salmon were evaluated during 2015–16. A paired-release study design was used that included release sites located upstream and downstream of Cowlitz Falls Dam. The downstream release site was positioned at the downstream margin of the dam’s tailrace, which allowed dam passage survival to be measured in a manner that included mortality that occurred in the passage route and in the dam tailrace. More than one-half of the tagged Chinook salmon (52 percent

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. Copyright © 2014 Elsevier B.V. All rights reserved.

The NSW Steam Trawl Fishery on the South-East Continental Shelf of Australia, 1915–1961

DEFF Research Database (Denmark)

Lund Jacobsen, A. Lif

2014-01-01

How was modern fishing methods, in the form of steam trawling, introduced in Australia? And what were the consequences for the fish stocks found on the South-East Continental Shelf? Through historical catch records and archival resources, the history of the NSW Steam Trawl Industry from 1915...

75 FR 4684 - Fisheries off West Coast States; Pacific Coast Groundfish Fishery; Data Collection for the Trawl...

Science.gov (United States)

2010-01-29

... Coast groundfish fishery. The trawl rationalization program is intended to increase net economic benefits, create individual economic stability, provide full utilization of the trawl sector allocation... one time reporting will have a significant economic impact on small entities, as the estimated...

Bayesian spatio-temporal discard model in a demersal trawl fishery

Science.gov (United States)

Grazia Pennino, M.; Muñoz, Facundo; Conesa, David; López-Quílez, Antonio; Bellido, José M.

2014-07-01

Spatial management of discards has recently been proposed as a useful tool for the protection of juveniles, by reducing discard rates and can be used as a buffer against management errors and recruitment failure. In this study Bayesian hierarchical spatial models have been used to analyze about 440 trawl fishing operations of two different metiers, sampled between 2009 and 2012, in order to improve our understanding of factors that influence the quantity of discards and to identify their spatio-temporal distribution in the study area. Our analysis showed that the relative importance of each variable was different for each metier, with a few similarities. In particular, the random vessel effect and seasonal variability were identified as main driving variables for both metiers. Predictive maps of the abundance of discards and maps of the posterior mean of the spatial component show several hot spots with high discard concentration for each metier. We argue how the seasonal/spatial effects, and the knowledge about the factors influential to discarding, could potentially be exploited as potential mitigation measures for future fisheries management strategies. However, misidentification of hotspots and uncertain predictions can culminate in inappropriate mitigation practices which can sometimes be irreversible. The proposed Bayesian spatial method overcomes these issues, since it offers a unified approach which allows the incorporation of spatial random-effect terms, spatial correlation of the variables and the uncertainty of the parameters in the modeling process, resulting in a better quantification of the uncertainty and accurate predictions.

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...

Modelling and simulation of size selectivity in diamond mesh trawl cod-ends

DEFF Research Database (Denmark)

Herrmann, Bent

of the fishing gear. The cod-end is the rearmost part of a trawl where catch accumulates and in which most of the size selection is known to take place. To date, the main method used to assess the selectivity of trawl cod-ends has been to run sea trials followed by statistical analysis of the obtained......Within many fisheries there is a widespread discard of fish. Furthermore, there are several fisheries where fish are caught before reaching the optimal size, leading to an adverse exploitation of the resources. One way to achieve a more optimal exploitation is to improve the size selectivity...

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.

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...

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....

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....

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....

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....

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....

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....

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....

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....

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....

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....

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....

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....

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....

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....

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....

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....

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....

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....

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....

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....

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....

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....

NEFSC 2016 Fall Bottom Trawl Survey (HB1604, 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....

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....

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....

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....

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....

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....

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....

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....

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....

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....

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....

NEFSC 2016 Spring Bottom Trawl Survey (HB1601, 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....

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....

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.

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

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

Drone Use in Monioring Open Ocean Surface Debris, Including Paired Manta and Tucker Trawls for Relateing Sea State to Vertical Debris Distribution

Science.gov (United States)

Lattin, G.

2016-02-01

Monitoring debris at sea presents challenges not found in beach or riverine habitats, and is typically done with trawl nets of various apertures and mesh sizes, which limits the size of debris captured and the area surveyed. To partially overcome these limitations in monitoring floating debris, a Quadcopter drone with video transmitting and recording capabilities was deployed at the beginning and the end of manta trawl transects within the North Pacific Subtropical Gyre's eastern convergence zone. Subsurface tucker trawls at 10 meters were conducted at the same time as the manta trawls, in order to assess the effect of sea state on debris dispersal. Trawls were conducted on an 11 station grid used repeatedly since 1999. For drone observations, the operator and observer were stationed on the mother ship while two researchers collected observed debris using a rigid inflatable boat (RIB). The drone was flown to a distance of approximately 100 meters from the vessel in a zigzag or circular search pattern. Here we examine issues arising from drone deployment during the survey: 1) relation of area surveyed by drone to volume of water passing through trawl; 2) retrieval of drone-spotted and associated RIB spotted debris. 3) integrating post- flight image analysis into retrieved debris quantification; and 4) factors limiting drone effectiveness at sea. During the survey, debris too large for the manta trawl was spotted by the drone, and significant debris not observed using the drone was recovered by the RIB. The combination of drone sightings, RIB retrieval, and post flight image analysis leads to improved monitoring of debris at sea. We also examine the issue of the distribution of floating debris during sea states varying from 0-5 by comparing quantities from surface manta trawls to the tucker trawls at a nominal depth of 10 meters.

A Study of Stranding of Juvenile Salmon by Ship Wakes Along the Lower Columbia River Using a Before-and-After Design: Before-Phase Results

Energy Technology Data Exchange (ETDEWEB)

Pearson, Walter H.; Skalski, J R.; Sobocinski, Kathryn L.; Miller, Martin C.; Johnson, Gary E.; Williams, Greg D.; Southard, John A.; Buchanan, Rebecca A.

2006-02-01

Ship wakes produced by deep-draft vessels transiting the lower Columbia River have been observed to cause stranding of juvenile salmon. Proposed deepening of the Columbia River navigation channel has raised concerns about the potential impact of the deepening project on juvenile salmon stranding. The Portland District of the U.S. Army Corps of Engineers requested that the Pacific Northwest National Laboratory design and conduct a study to assess stranding impacts that may be associated with channel deepening. The basic study design was a multivariate analysis of covariance of field observations and measurements under a statistical design for a before and after impact comparison. We have summarized field activities and statistical analyses for the ?before? component of the study here. Stranding occurred at all three sampling sites and during all three sampling seasons (Summer 2004, Winter 2005, and Spring 2005), for a total of 46 stranding events during 126 observed vessel passages. The highest occurrence of stranding occurred at Barlow Point, WA, where 53% of the observed events resulted in stranding. Other sites included Sauvie Island, OR (37%) and County Line Park, WA (15%). To develop an appropriate impact assessment model that accounted for relevant covariates, regression analyses were conducted to determine the relationships between stranding probability and other factors. Nineteen independent variables were considered as potential factors affecting the incidence of juvenile salmon stranding, including tidal stage, tidal height, river flow, current velocity, ship type, ship direction, ship condition (loaded/unloaded), ship speed, ship size, and a proxy variable for ship kinetic energy. In addition to the ambient and ship characteristics listed above, site, season, and fish density were also considered. Although no single factor appears as the primary factor for stranding, statistical analyses of the covariates resulted in the following equations: (1) Stranding

Using a laboratory-based growth model to estimate mass- and temperature-dependent growth parameters across populations of juvenile Chinook Salmon

Science.gov (United States)

Perry, Russell W.; Plumb, John M.; Huntington, Charles

2015-01-01

To estimate the parameters that govern mass- and temperature-dependent growth, we conducted a meta-analysis of existing growth data from juvenile Chinook Salmon Oncorhynchus tshawytscha that were fed an ad libitum ration of a pelleted diet. Although the growth of juvenile Chinook Salmon has been well studied, research has focused on a single population, a narrow range of fish sizes, or a narrow range of temperatures. Therefore, we incorporated the Ratkowsky model for temperature-dependent growth into an allometric growth model; this model was then fitted to growth data from 11 data sources representing nine populations of juvenile Chinook Salmon. The model fit the growth data well, explaining 98% of the variation in final mass. The estimated allometric mass exponent (b) was 0.338 (SE = 0.025), similar to estimates reported for other salmonids. This estimate of b will be particularly useful for estimating mass-standardized growth rates of juvenile Chinook Salmon. In addition, the lower thermal limit, optimal temperature, and upper thermal limit for growth were estimated to be 1.8°C (SE = 0.63°C), 19.0°C (SE = 0.27°C), and 24.9°C (SE = 0.02°C), respectively. By taking a meta-analytical approach, we were able to provide a growth model that is applicable across populations of juvenile Chinook Salmon receiving an ad libitum ration of a pelleted diet.

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.

Feeding Activity, Rate of Consumption, Daily Ration and Prey Selection of Major Predators in John Day Reservoir, 1984 : Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Gray, Gerard A.; United States. Bonneville Power Administration; U.S. Fish and Wildlife Service; National Fishery Research Center (U.S.)

1986-07-01

The extent of predation on juvenile salmonids in John Day Reservoir was determined. Salmonids were the single most important food item by weight for northern squawfish (Ptychocheilus oregonensis) in the restricted zones at McNary tailrace and John Day forebay during all sampling periods. Salmonids accounted for 18.1% of the weight in the diet of walleyes (Stizostedion vitreum vitreum) in 1984 which was at least twice that found in previous years. In smallmouth bass (Micropterus dolomieui) salmonids contributed little to their diet whereas for channel catfish (Ictalurus punctatus) fish accounted for 64.1% of the weight in their diet with salmonids responsible for approximately half of this weight. An intensive search of the fisheries literature was conducted to review various fish capture and control techniques which might have potential as predation control measures for the major predators of juvenile salmonids in the Columbia River system. Most prey protection measures were judged to have high potential and direct predator control measures were judged to have moderate or low potential.

Environmental Assessment : Squawfish Management Program : Final.

Energy Technology Data Exchange (ETDEWEB)

United States. Bonneville Power Administration.

1992-05-01

Bonneville Power Administration (BPA) proposes to decrease the number of northern squawfish (Ptychocheilus oregonensis) in reservoirs in the Columbia River system. The goal of the Squawfish Management Program is to reduce losses of outmigrating juvenile salmon and steelhead (salmonids) to northern squawfish predation. The objective is to reduce the number of northern squawfish that feed on juvenile salmonids (smolts) by 10 to 20 percent to alter the age and size structure of the northern squawfish population. The hypothesis, based on computer modeling, indicates that sustained northern squawfish harvest (5 to 10 years) and the resultant population restructuring may reduce losses of juvenile salmonids to predation by up to 50 percent or more within 10 years. The proposed action would target northern squawfish 11 inches and longer, the size in which northern squawfish being preying significantly on juvenile salmonids. BPA proposes to fund three types of fisheries to harvest northern squawfish. BPA also proposes to fund monitoring activities of these fisheries to determine whether desired or other results occur. The three fisheries methods proposed are: (1) commercial Tribal fishing; (2) sport reward fishing; and (3) fishing from restricted areas of each dam ( dam angling''). These fisheries were tested in 1990 and 1991.

Development of a systemwide predator control program: Stepwise implementation of a predation index, predator control fisheries, and evaluation plan in the Columbia River Basin. Volume 2 -- Evaluation: 1993 Annual report

International Nuclear Information System (INIS)

Willis, C.F.; Ward, D.L.

1995-06-01

An attempt was made to determine the extent to which northern squawfish predation on juvenile salmonids is a problem in the Columbia River Basin, and to evaluate how effectively fisheries can be used to control northern squawfish populations and reduce juvenile salmonid losses to predation. These studies were initiated as part of a basinwide program to control northern squawfish predation and reduce mortality of juvenile salmonids on their migration to the ocean. Modeling simulations based on work in the John Day Reservoir from 1982 through 1988 indicated that if northern squawfish larger than 250 mm fork length were exploited, at a rate of 10--20%, reductions in their numbers and restructuring of their populations could reduce their predation on juvenile salmonids by 50% or more. The authors evaluated the success of three test fisheries conducted in 1993--a sport-reward fishery, a dam-angling fishery, and a trap-net fishery, to achieve a 10--20% exploitation rate on northern squawfish. The authors also began evaluating the response of northern squawfish populations to sustained fisheries. In addition, the authors gathered information regarding the economic, social, and legal feasibility of sustaining each fishery, and report on the structure and function of the fish collection and distribution system

The footprint of salmonids on river morphology

Science.gov (United States)

Hassan, M. A.; Tonina, D.

2012-12-01

Female salmonids dig a pit in the streambed where they lay their eggs, which then cover with sediment from a second pit forming an egg nest call redd. This formation results in a shape resembling a dune with an amplitude, which is the vertical difference between bottom of the pit and crest of the hump, varying from few centimetres (for small fish, chum or sockeye salmon) to tenths of a meter (for large fish, Chinook salmon). During redd construction, salmonids alter streambed topography, winnow away fine sediment and mix streambed material within a layer as thick as 50 cm, for the large chinook salmon. The spawning activities may result in additional roughness at the local scale due to redds. However, redd construction may smooth large-scale topography reducing roughness due the macro-bedform. These topographical changes vary streambed roughness, which in turn may affect shear stress distribution. Redds have been suggested to increase the overall flow resistance due to form drag resulting in lower grain shear stress and less particle mobility. However, the mixing of the sediment could prevent armouring of the streambed surface allowing higher than with armouring sediment transport. Here, we use detailed pre- and post-spawning bathymetries coupled with accurate 2-dimensional hydraulic numerical modelling to test which of these two effects has potentially more impact on sediment transport. Our results show that topographical roughness added by sockeye salmons, which build small redds with 15cm amplitude and 1 meter wavelength (longitudinal length of a redd), has negligible effect on shear stress at the reach-scale and limited at the local scale. Conversely, sediment mixing has an important effect on reducing armouring, increasing sediment mobility, which results in potentially more sediment transport in reaches with than without redds. Consequently, salmonid bioturbation due to mass-spawning fish can be a dominant element for sediment transport in mountain drainage

A knowledge platform to inform on the effects of trawling on benthic communities

Science.gov (United States)

Muntadas, Alba; Lample, Michel; Demestre, Montserrat; Ballé-Béganton, Johanna; de Juan, Silvia; Maynou, Francesc; Bailly, Denis

2018-02-01

For a successful implementation of an Ecosystem Approach to Fisheries (EAF) management, it is necessary that all stakeholders involved in fisheries management are aware of the implications of fishing impacts on ecosystems and agree with the adopted measures to mitigate these impacts. In this context, there is a need for tools to share knowledge on the ecosystem effects of fisheries among these stakeholders. When managing bottom trawl fisheries under an EAF framework, one of the main concerns is the direct and indirect consequences of trawling impacts on benthic ecosystems. We developed a platform using the ExtendSim® software with a user-friendly interface that combines a simulation model based on existing knowledge, data collection and representation of predicted trawling impacts on the seabed. The platform aims to be a deliberation support tool for fisheries' stakeholders and, simultaneously, raise public awareness of the need for good benthic community knowledge to appropriately inform EAF management plans. The simulation procedure assumes that trawling affects benthic communities with an intensity that depends on the level of fishing effort exerted on benthic communities and on the habitat characteristics (i.e. sediment grain size). Data to build the simulation comes from epifaunal samples from 18 study sites located in Mediterranean continental shelves subjected to different levels of fishing effort. In this work, we present the simulation outputs of a 50% fishing effort increase (and decrease) in four of the study sites which cover different habitats and different levels of fishing effort. We discuss the platform strengths and weaknesses and potential future developments.

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,...

76 FR 57679 - Fisheries of the Exclusive Economic Zone Off Alaska; Shallow-Water Species by Vessels Using Trawl...

Science.gov (United States)

2011-09-16

.... 101126522-0640-02] RIN 0648-XA704 Fisheries of the Exclusive Economic Zone Off Alaska; Shallow- Water... closure. SUMMARY: NMFS is opening directed fishing for shallow-water species by vessels using trawl gear... apportionment of the 2011 Pacific halibut bycatch allowance specified for the trawl shallow-water species...

75 FR 56017 - Fisheries of the Exclusive Economic Zone Off Alaska; Shallow-Water Species by Vessels Using Trawl...

Science.gov (United States)

2010-09-15

.... 0910131362-0087-02] RIN 0648-XZ06 Fisheries of the Exclusive Economic Zone Off Alaska; Shallow- Water Species... closure. SUMMARY: NMFS is opening directed fishing for shallow-water species by vessels using trawl gear... of the 2010 Pacific halibut bycatch allowance specified for the trawl shallow-water species fishery...

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

Assessing and mitigating of bottom trawling. Final BENTHIS project Report (Benthic Ecosystem Fisheries Impact Study)

DEFF Research Database (Denmark)

Rijnsdorp, Adriaan D; Eigaard, Ole Ritzau; Kenny, Andrew

2017-01-01

the fuel cost without affecting the catch rate of the target species. Replacing mechanical stimulation by tickler chains with electrical stimulation In the beam trawl fishery for sole, reduced footprint and penetration depth as well as the fuel cost. Electrical stimulation is also a promising innovation...... to reduce the bycatch and bottom contact in the beam trawl fishery for brown shrimps. Sea trials to replace bottom trawls with pots were inconclusive. Results suggest that creels may offer an alternative for small Nephrops fishers in the Kattegat. In waters off Greece, the catch rates were very low. Sea...... trials with the blue mussel fishery showed that fishers could reduce their footprint by deploying acoustic equipment to detect mussel concentrations that allow the fishers to more precisely target the mussel beds and hence reduce fishing in areas with low mussel density. A review of the various case...

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...

Spring Coastal Pelagic Species Acoustic Trawl Survey (SH1404, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — 14 Acoustic transects were run offshore of Southern California between San Francisco and Cape Mendocino, CA with CTD casts conducted daily and trawls nightly based...

Trawl survey data are applied in fish stock assessment mainly to ...

African Journals Online (AJOL)

denise

Merluccius capensis (shallow-water Cape hake) and. M. paradoxus (deep-water Cape hake) off Namibia provide an ... published data), meaning that the horizontal trawl opening will .... Acoustic data were post-processed twice daily. Hake.

Bycatch of crustacean and fish bottom trawl fisheries from southern Portugal (Algarve

Directory of Open Access Journals (Sweden)

Maria Esmeralda Costa

2008-12-01

Full Text Available As part of two research projects for analysing bycatch and discards, we quantified catch composition, catch rates, bycatch and discards in two important commercial bottom trawl fisheries (crustacean and fish trawls off the southern coast of Portugal (Algarve. Stratified sampling by onboard observers took place from February 1999 to March 2001 and data were collected from 165 tows during 52 fishing trips. Commercial target species included crustaceans: blue and red shrimp (Aristeus antennatus, deep-water rose shrimp (Parapenaeus longirostris, Norway lobster (Nephrops norvegicus; and fishes: seabreams (Diplodus spp. and Pagellus spp., horse mackerels (Trachurus spp. and European hake (Merluccius merluccius. The trawl fisheries are characterised by considerable amounts of bycatch: 59.5% and 80.4% of the overall total catch for crustacean and fish trawlers respectively. A total of 255 species were identified, which belonged to 15 classes of organisms (137 vertebrates, 112 invertebrates and 6 algae. Crustacean trawlers had higher bycatch biodiversity. Bony fish (45.6% and 37.8% followed by crustaceans (14.6% and 11.5% were the dominant bycatch components of both crustacean and fish trawlers respectively. The influence of a number of factors (e.g. depth, fishing gear, tow duration and season on bycatch and discards is discussed.

Fish distribution studies near N Reactor, Summer 1983

Energy Technology Data Exchange (ETDEWEB)

Dauble, D.D.; Page, T.L.

1984-06-01

This report summarizes field studies that were initiated in July 1983 to provide estimates of the relative distribution of late-summer outmigrant juvenile salmonids and juvenile resident fish upstream of the N Reactor 009 Outfall. Chinook salmon are among the fish species most sensitive to thermal effects, and impacts to the juvenile outmigrant populations are of particular concern to state and federal regulatory and fisheries management agencies. Therefore, the distribution studies were conducted from late July through September, a period when high ambient river temperatures and low river flows make these salmonid populations most susceptible to thermal effects. In addition, data were not available on the spatial distribution of outmigrant juvenile chinook salmon in late summer. Information on the relative distribution of resident fish populations was also gathered. Previous studies of midstream distribution of juvenile resident fish were limited to a description of ichthyoplankton populations (Beak Consultants, Inc. 1980 Page et al. 1982), and no data were available on vertical or horizontal distribution of juvenile resident fish species near N Reactor. Relative densities and spatial distribution estimates of juvenile salmonid and resident fish species will be used in conjunction with laboratory thermal effects studies (Neitzel et al. 1984) and with plume characterization studies (Ecker et al. 1983) to assess potential impacts of thermal discharge on fish populations near N Reactor.

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...

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.

Job satisfaction in the shrimp trawl fisheries of Chennai, India

NARCIS (Netherlands)

Bavinck, M.

2012-01-01

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

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

such as logbook data. Here, we take a different approach starting from the gear itself (design and dimensions) to estimate the physical interactions with the seabed at the level of the individual fishing operation. We defined 14 distinct towed gear groups in European waters (eight otter trawl groups, three beam...... 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...... to enable the prediction of gear footprint area and sediment penetration from vessel size. Application of these relationships with average vessel sizes and towing speeds provided hourly swept-area estimates by métier. Scottish seining has the largest overall gear footprint of ∼1.6 km2 h−1 of which 0.08 km2...

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...

Variation in salmonid life histories: patterns and perspectives.

Science.gov (United States)

Mary F. Willson

1997-01-01

Salmonid fishes differ in degree of anadromy, age of maturation, frequency of reproduction, body size and fecundity, sexual dimorphism, breeding season, morphology, and, to a lesser degree, parental care. Patterns of variation and their possible significance for ecology and evolution and for resource management are the focus of this review.

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...

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…

Final report of the Working Group on electrical Trawling

NARCIS (Netherlands)

Haan, de D.; Molenaar, P.; Rijnsdorp, A.D.; Steenbergen, J.; Marlen, van B.

2017-01-01

WGELECTRA met three times (22–24/10/2014; 10–12/11/2015, and 17–19/01/2017) to discuss the ongoing research projects in Belgium, the Netherlands, and Germany and provide an overview of the state of the art knowledge of the ecological effects. Pulse trawls are used in the North Sea fishery for

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...

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...

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...

Identification of Two Pathogenic Aeromonas Species Isolated during Production Related Epizootics from Juvenile Burbot Lota lota maculosa.

Science.gov (United States)

Terrazas, Marc M; Anderson, Cort L; Jacobs, Sarah J; Cain, Kenneth D

2018-05-25

In response to population declines of Burbot Lota lota maculosa, conservation aquaculture methods have been developed for this species. In general, Burbot are relatively resistant to many salmonid pathogens; however, cultured juvenile Burbot have experienced periodic epizootic disease outbreaks during production. A series of trials were conducted to determine the virulence of select bacteria isolated from juvenile Burbot following outbreaks that occurred in 2012 and 2013 at the University of Idaho's Aquaculture Research Institute. Initial clinical diagnostics and sampling resulted in the isolation of numerous putative bacterial pathogens. To determine which bacteria were the most likely causative agents contributing to these epizootics, juvenile Burbot were injectied intraperitoneally (IP) with select bacteria in log phase growth. Mortality associated with specific isolates was recorded, and more comprehensive challenges followed this initial screening. These challenges used side-by-side IP and immersion methods to expose Burbot to potential pathogens. The challenges resulted in significantly higher mortalities in fish following IP injection of two Aeromonas sp. isolates compared to controls (P ≤ 0.01), but no difference in mortality for immersion challenged groups was observed (P = 0.42). Results demonstrate that two isolates (Aeromonas sp.) cultured from the epizootics are virulent to Burbot. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

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…

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...

ADULT COHO SALMON AND STEELHEAD USE OF BOULDER WEIRS IN SOUTHWEST OREGON STREAMS

Science.gov (United States)

The placement of log and boulder structures in streams is a common and often effective technique for improving juvenile salmonid rearing habitat and increasing fish densities. Less frequently examined has been the use of these structures by adult salmonids. In 2004, spawner densi...

Gauging resource exploitation by juvenile Chinook salmon (Oncorhynchus tshawytscha) in restoring estuarine habitat

Science.gov (United States)

Davis, Melanie; Ellings, Christopher S.; Woo, Isa; Hodgson, Sayre; Larsen, Kimberly A.; Nakai, Glynnis

2018-01-01

In the context of delta restoration and its impact on salmonid rearing, success is best evaluated based on whether out-migrating juvenile salmon can access and benefit from suitable estuarine habitat. Here, we integrated 3 years of post-restoration monitoring data including habitat availability, invertebrate prey biomass, and juvenile Chinook salmon (Oncorhynchus tshawytscha) physiological condition to determine whether individuals profited from the addition of 364 ha of delta habitat in South Puget Sound, Washington, United States. Productivity in the restored mudflat was comparable to reference sites 3 years after dike removal, surpassing a mean total of 6 million kJ energy from invertebrate prey. This resulted from the development of a complex network of tidal channels and a resurgence in dipteran biomass that was unique to the restoration area. Consequently, a notable shift in invertebrate consumption occurred between 2010 and 2011, whereby individuals switched from eating primarily amphipods to dipteran flies; however, dietary similarity to the surrounding habitat did not change from year to year, suggesting that this shift was a result of a change in the surrounding prey communities. Growth rates did not differ between restored and reference sites, but catch weight was positively correlated with prey biomass, where greater prey productivity appeared to offset potential density-dependent effects. These results demonstrate how the realized function of restoring estuarine habitat is functionally dependent. High prey productivity in areas with greater connectivity may support healthy juvenile salmon that are more likely to reach the critical size class for offshore survival.

Many Species, Many Threats: A Composite Risk Assessment of Climate Impacts for Salmonids in the Pacific Northwest

Science.gov (United States)

Graham, M. C.; Greene, C.; Beechie, T. J.; Raymond, C.

2016-02-01

The life cycles of salmonid species span freshwater, estuarine, and marine environments, exposing these economically, ecologically, and culturally important species to a wide variety of climate change threats. The diverse life histories of salmonids make them differentially vulnerable to climate change based on their use of different habitat types and the variability in climate change threats across these habitat types. Previous studies have focused mainly on assessing the vulnerability of particular life stages for a few species. Hence, we lack a broad perspective on how multiple climate threats are expected to impact the entire salmonid community, which spend much of their lives in marine waters. This lack of knowledge hampers our ability to prioritize various adaptation strategies for salmonid conservation. In order to conduct a more extensive vulnerability study of salmonids, we performed a life cycle-based risk assessment of climate change threats for nine species of salmonids (species within Oncorhynchus, Salvelinus, and Prosopium genera) inhabiting the Skagit River watershed, which is subject to an array of climate impacts. Our risk assessment integrated projections of impacts from various climate threats in freshwater, estuarine, and marine ecosystems with expert-based assessments of species-specific sensitivity and exposure. We found that projections (multiple global climate models under moderate emission scenarios) of both changes in magnitude and frequency of three flow-related freshwater impacts (flooding, low flows, and suspended sediment pulses) were more severe than threats in estuarine and marine habitats for which we could obtain projections. Combining projections with expert-based sensitivity and exposure scores revealed that these three threats exhibited the highest risk across all species. Of the nine species, the four most vulnerable were Chinook and coho salmon, steelhead, and bull trout. Even though these salmonids spend much of their lives

Comparative distribution of the fan mussel Atrina fragilis (Bivalvia, Pinnidae in protected and trawled areas of the north Aegean Sea (Thermaikos Gulf

Directory of Open Access Journals (Sweden)

K. FRYGANIOTIS

2013-02-01

Full Text Available The distribution of the fan mussel Atrina fragilis was studied at two contrasting areas of the north Aegean Sea (Thermaikos Gulf: one routinely trawled and one closed to trawlers for over 25 years. Significant differences were detected between the two areas with decreased values in density and size of A. fragilis individuals at the trawled area. As habitat differences, i.e. sediment composition and bathymetry, had non-significant effect, extensive trawling activities probably explain the observed results.

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

The effect of rapid and sustained decompression on barotrauma in juvenile brook lamprey and Pacific lamprey: implications for passage at hydroelectric facilities

Energy Technology Data Exchange (ETDEWEB)

Colotelo, Alison HA; Pflugrath, Brett D.; Brown, Richard S.; Brauner, Colin J.; Mueller, Robert P.; Carlson, Thomas J.; Deng, Zhiqun; Ahmann, Martin L.; Trumbo, Bradly A.

2012-10-01

Fish passing downstream through hydroelectric facilities may pass through hydroturbines where they experience a rapid decrease in barometric pressure as they pass by turbine blades, which can lead to barotraumas including swim bladder rupture, exopthalmia, emboli, and hemorrhaging. In juvenile Chinook salmon, the main mechanism for injury is thought to be expansion of existing gases (particularly those present in the swim bladder) and the rupture of the swim bladder ultimately leading to exopthalmia, emboli and hemorrhaging. In fish that lack a swim bladder, such as lamprey, the rate and severity of barotraumas due to rapid decompression may be reduced however; this has yet to be extensively studied. Another mechanism for barotrauma can be gases coming out of solution and the rate of this occurrence may vary among species. In this study, juvenile brook and Pacific lamprey acclimated to 146.2 kPa (equivalent to a depth of 4.6 m) were subjected to rapid (<1 sec; brook lamprey only) or sustained decompression (17 minutes) to a very low pressure (13.8 kPa) using a protocol previously applied to juvenile Chinook salmon. No mortality or evidence of barotraumas, as indicated by the presence of hemorrhages, emboli or exopthalmia, were observed during rapid or sustained decompression, nor following recovery for up to 120 h following sustained decompression. In contrast, mortality or injury would be expected for 97.5% of juvenile Chinook salmon exposed to a similar rapid decompression to these very low pressures. Additionally, juvenile Chinook salmon experiencing sustained decompression died within 7 minutes, accompanied by emboli in the fins and gills and hemorrhaging in the tissues. Thus, juvenile lamprey may not be susceptible to barotraumas associated with hydroturbine passage to the same degree as juvenile salmonids, and management of these species should be tailored to their specific morphological and physiological characteristics.

Invasion versus isolation: trade-offs in managing native salmonids with barriers to upstream movement.

Science.gov (United States)

Fausch, Kurt D; Rieman, Bruce E; Dunham, Jason B; Young, Michael K; Peterson, Douglas P

2009-08-01

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 frequently relegated to fragments of headwater habitat threatened by invasion from downstream by 3 cosmopolitan non-native salmonids. Managers often block these upstream invasions with movement barriers, but isolation of native salmonids in small headwater streams can increase the threat of local extinction. We propose a conceptual framework to address this worldwide problem that focuses on 4 main questions. First, are populations of conservation value present (considering evolutionary legacies, ecological functions, and socioeconomic benefits as distinct values)? Second, are populations vulnerable to invasion and displacement by non-native salmonids? Third, would these populations be threatened with local extinction if isolated with barriers? And, fourth, how should management be prioritized among multiple populations? We also developed a conceptual model of the joint trade-off of invasion and isolation threats that considers the opportunities for managers to make strategic decisions. We illustrated use of this framework in an analysis of the invasion-isolation trade-off for native cutthroat trout (Oncorhynchus clarkii) in 2 contrasting basins in western North America where invasion and isolation are either present and strong or farther away and apparently weak. These cases demonstrate that decisions to install or remove barriers to conserve native salmonids are often complex and depend on conservation values, environmental context (which influences the threat of invasion and isolation), and additional socioeconomic factors. Explicit analysis with tools such as those we propose can help managers make

Climate-induced trends in predator–prey synchrony differ across life-history stages of an anadromous salmonid

Science.gov (United States)

Bell, Donovan A.; Kovach, Ryan; Vulstek, Scott C.; Joyce, John E.; Tallmon, David A.

2017-01-01

Differential climate-induced shifts in phenology can create mismatches between predators and prey, but few studies have examined predator–prey mismatch across multiple life-history stages. We used long-term data from a warming stream with shifting salmonid migration timings to quantify intra-annual migration synchrony between predatory Dolly Varden (Salvelinus malma) and Pacific salmon prey and examined how predator–prey synchrony has been influenced by climate change. We demonstrate that Dolly Varden have become increasingly mismatched with spring downstream migrations of abundant pink salmon (Oncorhynchus gorbuscha) juveniles. However, Dolly Varden have remained matched with fall upstream migrations of spawning Pacific salmon, including coho (Oncorhynchus kisutch), sockeye (Oncorhynchus nerka), and pink salmon. Downstream predator–prey migration synchrony decreased over time and with higher temperatures, particularly with pink salmon. In contrast, upstream migration synchrony was temporally stable and increased with rising temperatures. Differing trends in Dolly Varden predator–prey synchrony may be explained by the direct use of salmon to cue upstream migration, but not downstream migration. Overall, we show that climate change can have differing impacts on predator–prey synchrony across life-history stages.

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...

Hydrodynamic characteristics of the oval cambered double slotted otter board in bottom trawl fisheries

Science.gov (United States)

Liu, J.; Huang, H. L.; Li, L. Z.; Qu, T. C.; Wu, Y.; Chen, S.; Yang, J. L.; Rao, X.

2017-07-01

The otter board is one of the main components of single boat trawl fisheries. An oval cambered double slotted otter board was developed for improving the expansion performance of trawl net in bottom trawl fisheries. A flume model experiment was conducted to measure the lift coefficient (C L), drag coefficient (C D), and lift to drag ratio (K) in different angles of attack (α). The experimental results are as follows : (1) The C L and K value show a trend of increasing at the beginning and then decreasing with the increase of angle of attack, the C D value reflects an upward trend as the angle of attack increases; (2) The D3 otter board (front flow deflector angle at 29°) showed a better hydrodynamic performance. When α=30°, the max lift coefficient (C Lmax) was 1.464, in this case C D = 0.554 and K=2.643. When α=15°, the max lift to drag ratio (K max) was 4.165, C L =0.633, and C D = 0.152. This suggests that the best working scope for the angle of attack is between 15°~30°, in which case, C L>0.633 and K>2.643. The mean value of the lift coefficient was 1.071 and the mean of the lift to drag ratio was 3.482. Comparative analysis of the hydrodynamic performance of different types of otter boards showed that the D3 otter board both had good expansion performance and efficiency, which can provide a reference basis for further optimization of the bottom trawl otter board.

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

OpenAIRE

Korsu, K. (Kai)

2008-01-01

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

50 CFR 660.381 - Limited entry trawl fishery management measures.

Science.gov (United States)

2010-10-01

... or tied along the length of the footrope). Other lines or ropes that run parallel to the footrope may... gear must have unprotected footropes at the trawl mouth, and must not have rollers, bobbins, tires... gear may not be enlarged by encircling it with chains or by any other means. Ropes or lines running...

Underwater methods for study of salmonids in the Intermountain West

Science.gov (United States)

Russell F. Thurow

1994-01-01

This guide describes underwater methods using snorkeling gear to study fish populations in flowing waters of the Intermountain West. It outlines procedures for estimating salmonid abundance and habitat use and provides criteria for identifying and estimating the size of fish underwater.

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,...

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

Science.gov (United States)

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

2011-01-01

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

Enhanced invertebrate prey production following estuarine restoration supports foraging for multiple species of juvenile salmonids (Oncorhynchus spp.)

Science.gov (United States)

Woo, Isa; Davis, Melanie; Ellings, Christopher S.; Nakai, Glynnis; Takekawa, John Y.; De La Cruz, Susan

2018-01-01

Estuaries provide crucial foraging resources and nursery habitat for threatened populations of anadromous salmon. As such, there has been a global undertaking to restore habitat and tidal processes in modified estuaries. The foraging capacity of these ecosystems to support various species of out-migrating juvenile salmon can be quantified by monitoring benthic, terrestrial, and pelagic invertebrate prey communities. Here, we present notable trends in the availability of invertebrate prey at several sites within a restoring large river delta in Puget Sound, Washington, U.S.A. Three years after the system was returned to tidal influence, we observed substantial additions to amphipod, copepod, and cumacean abundances in newly accessible marsh channels (from 0 to roughly 5,000–75,000 individuals/m2). In the restoration area, terrestrial invertebrate colonization was dependent upon vegetative cover, with dipteran and hymenopteran biomass increasing 3-fold between 1 and 3 years post-restoration. While the overall biodiversity within the restoration area was lower than in the reference marsh, estimated biomass was comparable to or greater than that found within the other study sites. This additional prey biomass likely provided foraging benefits for juvenile Chinook, chum, and coho salmon. Primary physical drivers differed for benthic, terrestrial, and pelagic invertebrates, and these invertebrate communities are expected to respond differentially depending on organic matter exchange and vegetative colonization. Restoring estuaries may take decades to meet certain success criteria, but our study demonstrates rapid enhancements in foraging resources understood to be used for estuary-dependent wildlife.

Growth, food consumption, and energy status of juvenile pallid sturgeon fed natural or artificial diets

Science.gov (United States)

Meyer, Hilary A.; Chipps, Steven R.; Graeb, Brian D. S.; Klumb, Robert A.

2016-01-01

Stocking of hatchery-raised fish is an important part of the pallid sturgeon Scaphirhynchus albus recovery program. In the wild, juvenile pallid sturgeon consume primarily aquatic insects, although little is known about specific dietary needs. In hatchery settings, pallid sturgeon are fed commercial diets that are formulated for salmonids. To compare food consumption, growth, and energy status of pallid sturgeon fed artificial or natural diets, we conducted a laboratory study using 24 juvenile pallid sturgeon (initial fork length 153–236 mm). Pallid sturgeon were fed a daily ration of either commercial pellets (1 mm, slow sinking; 45% protein, 19% fat) or chironomid larvae for 5 wk. Natural-fed pallid sturgeon exhibited a greater specific growth rate (2.12% d−1) than pellet-fed fish (0.06% d−1). Similarly, relative condition was greater for natural-fed sturgeon (Kn = 1.11) than that observed for pellet-fed fish (Kn = 0.87). In contrast, the hepatosomatic index was significantly higher in pellet-fed fish (2.5%), indicating a high lipid diet compared with natural-fed sturgeon (1.4%). Given the importance of natural diets to fish digestion and growth, it is suggested that a more holistic approach be applied in the development of a practical diet for pallid sturgeon that incorporates attributes of natural prey.

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....

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...... together with the bacteria in a ratio of 10 plaque‐forming units per colony‐forming unit. While we recognize the artificial laboratory conditions used for these protection assays, this work is the first to demonstrate that phages might be able protect salmonids from RTFS or CWD....

Predicting recolonization patterns and interactions between potamodromous and anadromous salmonids in response to dam removal in the Elwha River, Washington State, USA

Science.gov (United States)

Brenkman, S.J.; Pess, G.R.; Torgersen, C.E.; Kloehn, K.K.; Duda, J.J.; Corbett, S.C.

2008-01-01

The restoration of salmonids in the Elwha River following dam removal will cause interactions between anadromous and potamodromous forms as recolonization occurs in upstream and downstream directions. Anadromous salmonids are expected to recolonize historic habitats, and rainbow trout (Oncorhynchus mykiss) and bull trout (Salvelinus confluentus) isolated above the dams for 90 years are expected to reestablish anadromy. We summarized the distribution and abundance of potamodromous salmonids, determined locations of spawning areas, and mapped natural barriers to fish migration at the watershed scale based on data collected from 1993 to 2006. Rainbow trout were far more abundant than bull trout throughout the watershed and both species were distributed up to river km 71. Spawning locations for bull trout and rainbow trout occurred in areas where we anticipate returning anadromous fish to spawn. Nonnative brook trout were confined to areas between and below the dams, and seasonal velocity barriers are expected to prevent their upstream movements. We hypothesize that the extent of interaction between potamodromous and anadromous salmonids will vary spatially due to natural barriers that will limit upstream-directed recolonization for some species of salmonids. Consequently, most competitive interactions will occur in the main stem and floodplain downstream of river km 25 and in larger tributaries. Understanding future responses of Pacific salmonids after dam removal in the Elwha River depends upon an understanding of existing conditions of the salmonid community upstream of the dams prior to dam removal.

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.

Bycatch in 36 and 40 mm PA Turkish twin rigged beam trawl codends

African Journals Online (AJOL)

Jane

2011-07-20

Jul 20, 2011 ... Thus, landings of the shrimp beam trawling fleet also include some commercially valuable fishes. ... Fishing has significant direct and indirect effects on the habitat, diversity ..... Statistics 2006. State Institute of Statistics Prime.

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)...

How do land-based salmonid farms affect stream ecology?

International Nuclear Information System (INIS)

Tello, A.; Corner, R.A.; Telfer, T.C.

2010-01-01

Increasing research is highlighting the fact that streams provide crucial ecosystem services through the biogeochemical and ecological processes they sustain. Freshwater land-based salmonid farms commonly discharge their effluents into low order, headwater streams, partly due to the fact that adequate freshwater resources for production are commonly found in undisturbed areas. We review the effects of salmonid farm effluents on different biological components of stream ecosystems. Relevant considerations related to the temporal and spatial scales of effluent discharge and ecological effects are discussed. These highlight the need to characterize the patterns of stressor discharge when assessing environmental impacts and designing ecological effects studies. The potential role of multiple stressors in disrupting ecosystem structure and function is discussed with an emphasis on aquaculture veterinary medicines. Further research on the effects of veterinary medicines using relevant exposure scenarios would significantly contribute to our understanding of their impact in relation to other effluent stressors. - This article reviews the effects of aquaculture effluents on stream ecosystems with an emphasis on veterinary medicines and the temporal patterns of effluent discharge.

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...

Comparison of the movement and recapture of salmonid fishes tagged at two power plants

International Nuclear Information System (INIS)

Romberg, G.P.; Thommes, M.M.

1974-01-01

Fish tagging studies were conducted in the vicinity of Point Beach Nuclear Plant and Waukegan Power Plant to determine whether there were any seasonal or site specific differences in the residence behavior of salmonids at thermal discharges. Results showed that there were differences in the abundance and time of peak abundance of trout and salmon at the two power plant discharges. Certain species reacted differently to the two discharges probably as a result of maturity and water temperature. Salmonids did not appear to remain at either discharge for long periods. Direction of migration was affected by stocking location and water temperature

Diel effects on bottom-trawl survey catch rates of shallow- and deep ...

African Journals Online (AJOL)

Fishing in depths shallower than 400 m outside daylight hours should therefore be avoided in order to reduce bias and ensure consistency in abundance estimates from surveys. Keywords: Benguela Current system, consistency of survey indices, efficiency of bottom-trawl surveys, negative binomial GAM, transect survey ...

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...

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.

Crims Island-Restoration and monitoring of juvenile salmon rearing habitat in the Columbia River Estuary, Oregon, 2004-10

Science.gov (United States)

Haskell, Craig A.; Tiffan, Kenneth F.

2011-01-01

-channel' was extended westward and connected to Bradbury Slough to create a second outlet to the main river. New intertidal channels were constructed from the existing 'T-channel' and tidal mudflats became inundated at high tide to increase rearing habitat for juvenile salmonids. The restoration action resulted in a 95-percent increase in available juvenile salmon rearing habitat. We collected juvenile salmon and other fishes at Crims Island and a nearby reference site using beach seines and fyke nets annually from March through August during all years. Benthic invertebrates were collected with sediment corers and drift invertebrates were collected with neuston nets. Juvenile salmon stomach contents were sampled using lavage. Vegetation and sediments characteristics were surveyed and we conducted a topographic/bathymetric survey using a RTK (real time kinematic) GPS (global positioning system). The fish assemblage at Crims Island, composed primarily of threespine stickleback (Gasterosteus aculeatus), non-native banded killifish (Fundulus diaphanus), peamouth chub (Mylocheilus caurinus), subyearling Chinook salmon (Oncorhynchus tshawytscha) (hereinafter referred to as subyearlings), and small numbers of juvenile chum salmon (Oncorhynchus keta), did not differ appreciably pre- and post-restoration. Subyearlings were the primary salmonid collected and were seasonally abundant from April through May during all years. The abundance of juvenile salmon declined seasonally as water temperature exceeded 20 degrees C in the Reference site by mid-June; however, subyearlings persisted at the Mainstem site and in subtidal channels of the Restoration site through the summer in water temperatures exceeding 22 degrees C. Residence times of subyearlings in Crims Island backwaters generally were short consisting of one or two tidal cycles. Median residence time was longer in the Restoration site than in the Reference site pre- and post-restoration. Small (mean = 55.7 millimeters) subyea

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

Science.gov (United States)

Adams, Noah S.; Smith, Collin D.

2017-06-26

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

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.

Demersal trawling on the South African south and east coasts for the ...

African Journals Online (AJOL)

spamer

ralis was initiated in 1878, initially using a steam tug ... species composition, catch seasonality, catch per unit effort (cpue) and size-at-recruitment over the time ... Changes in the Eastern Cape demersal inshore trawl fishery operating out of Port ... MATERIAL AND METHODS ... The model parameters were estimated by mini-.

The design and analysis of salmonid tagging studies in the Columbia Basin. Volume 2: Estimating salmonid survival with combined PIT-CWT tagging. Technical report

International Nuclear Information System (INIS)

Newman, K.

1997-06-01

Passive Integrated Transponder (PIT) tags and Coded Wire Tags (CWTs) in combination can provide information about salmonid survival that single tag releases may not. The release and recapture protocol affects which survival and recapture rates can be estimated and the precision of the estimates. For the particular case of Columbia river salmonids tagged with both PIT tags and CWTs, three different release and recapture protocols were evaluated. This report addresses the need to study the fate of salmon smolt in-river and their subsequent return as adults. Double-tagging procedures are investigated where PIT-tags would be used to provide in-river survival data during smolt outmigrations and coded-wire tags (CWT) used to provide adult return information. This report provides statistical models for the analysis of the joint data as well as recommendations on optimal tagging studies. Study costs and stress on smolt can be reduced by only PIT-tagging a subset of all the fish coded-wire-tagged, while retaining the information content and sampling precision

Salmonid Chromosome Evolution as Revealed by a Novel Method for Comparing RADseq Linkage Maps

Science.gov (United States)

Gosselin, Thierry; Normandeau, Eric; Lamothe, Manuel; Isabel, Nathalie; Audet, Céline; Bernatchez, Louis

2016-01-01

Whole genome duplication (WGD) can provide material for evolutionary innovation. Family Salmonidae is ideal for studying the effects of WGD as the ancestral salmonid underwent WGD relatively recently, ∼65 Ma, then rediploidized and diversified. Extensive synteny between homologous chromosome arms occurs in extant salmonids, but each species has both conserved and unique chromosome arm fusions and fissions. Assembly of large, outbred eukaryotic genomes can be difficult, but structural rearrangements within such taxa can be investigated using linkage maps. RAD sequencing provides unprecedented ability to generate high-density linkage maps for nonmodel species, but can result in low numbers of homologous markers between species due to phylogenetic distance or differences in library preparation. Here, we generate a high-density linkage map (3,826 markers) for the Salvelinus genera (Brook Charr S. fontinalis), and then identify corresponding chromosome arms among the other available salmonid high-density linkage maps, including six species of Oncorhynchus, and one species for each of Salmo, Coregonus, and the nonduplicated sister group for the salmonids, Northern Pike Esox lucius for identifying post-duplicated homeologs. To facilitate this process, we developed MapComp to identify identical and proximate (i.e. nearby) markers between linkage maps using a reference genome of a related species as an intermediate, increasing the number of comparable markers between linkage maps by 5-fold. This enabled a characterization of the most likely history of retained chromosomal rearrangements post-WGD, and several conserved chromosomal inversions. Analyses of RADseq-based linkage maps from other taxa will also benefit from MapComp, available at: https://github.com/enormandeau/mapcomp/ PMID:28173098

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 many blood ...

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...

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...

Inshore small-mesh trawling survey of the Cape south coast. Part 5 ...

African Journals Online (AJOL)

Inshore small-mesh trawling survey of the Cape south coast. Part 5. Crustacea, Stomatopoda, Isopoda and. Decapoda. B. Kensley and C.D. Buxton. Port Elizabeth Museum, Port Elizabeth. Forty-six species of Crustacea from the shallow marine waters of the southern Cape coast are listed. Five new records for the area.

Fish behaviour in responce to a midwater trawl footrope in temperate reservoirs

Czech Academy of Sciences Publication Activity Database

Sajdlová, Zuzana; Draštík, Vladislav; Jůza, Tomáš; Říha, Milan; Frouzová, Jaroslava; Čech, Martin; Vašek, Mojmír; Muška, Milan; Blabolil, Petr; Tušer, Michal; Kratochvíl, Michal; Peterka, Jiří; Mrkvička, Tomáš; Balk, Helge; Kubečka, Jan

2015-01-01

Roč. 172, December (2015), s. 105-113 ISSN 0165-7836 R&D Projects: GA MŠk(CZ) EE2.3.20.0204 Institutional support: RVO:60077344 Keywords : pair trawling * avoidance behaviour * SED echogram * open water * vertical track slope Subject RIV: EH - Ecology, Behaviour Impact factor: 2.230, year: 2015

An extremely sensitive nested PCR-RFLP mitochondrial marker for detection and identification of salmonids in eDNA from water samples

Directory of Open Access Journals (Sweden)

Laura Clusa

2017-02-01

Full Text Available Background Salmonids are native from the North Hemisphere but have been introduced for aquaculture and sport fishing in the South Hemisphere and inhabit most rivers and lakes in temperate and cold regions worldwide. Five species are included in the Global Invasive Species Database: rainbow trout Oncorhynchus mykiss, Atlantic salmon Salmo salar, brown trout Salmo trutta, brook trout Salvelinus fontinalis, and lake trout Salvelinus namaycush. In contrast, other salmonids are endangered in their native settings. Methods Here we have developed a method to identify salmonid species directly from water samples, focusing on the Iberian Peninsula as a case study. We have designed nested Salmonidae-specific primers within the 16S rDNA region. From these primers and a PCR-RFLP procedure the target species can be unequivocally identified from DNA extracted from water samples. Results The method was validated in aquarium experiments and in the field with water from watersheds with known salmonid populations. Finally, the method was applied to obtain a global view of the Salmonidae community in Nalón River (north coast of Spain. Discussion This new powerful, very sensitive (identifying the species down to 10 pg DNA/ml water and economical tool can be applied for monitoring the presence of salmonids in a variety of situations, from checking upstream colonization after removal of river barriers to monitoring potential escapes from fish farms.

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...

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...... species caught in the trawls. To address this issue, we developed a novel sorting box concept consisting of a four-panel section with a window on the top in order to improve the escape of cod and other bycatch species through an escape window while retaining the target catch of Norway lobster. The concept....... The reduction in bycatch decreased with decreasing mesh size and increasing height of the sorting box. Escape of Norway lobster through the escape window was limited. A modified version of the sorting box concept was implemented in the Kattegat fishery from 2009 onwards...

Feasibility study for evaluating cumulative exposure of downstream migrant juvenile salmonids to total dissolved gas. Final report

International Nuclear Information System (INIS)

Abernethy, C.S.; Dauble, D.D.; Johnson, R.L.

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

Review of a model to assess stranding of juvenile salmon by ship wakes along the Lower Columbia River, Oregon and Washington

Science.gov (United States)

Kock, Tobias J.; Plumb, John M.; Adams, Noah S.

2013-01-01

uncertainty within a given set of model predictions, but such an approach would require a substantial amount of additional data collection. Several review questions focused on the accuracy and precision of the model estimates, but we were unable to address these questions because of the limited data that currently exists regarding wake stranding in the LCR. Additional field studies will be required to validate findings from Pearson (2011), if concerns regarding accuracy and precision remain a priority. Although the Pearson (2011) model provided a useful examination of stranding under pre-construction and post-construction conditions, future research will be required to better understand the effects of wake stranding on juvenile salmonids throughout the entire LCR. If additional information on wake stranding is desired in the future, the following topics may be of interest: (1) spatial examination of wake stranding throughout the entire LCR; (2) additional evaluation of juvenile salmonid behavior and population dynamics; (3) assessing and integrating predicted changes in ship development; and (4) assessing and integrating predicted changes in climate on environmental factors known to cause stranding.

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, Cecil 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.

Evaluation of Fish Passage Sites in the Walla Walla River Basin, 2008

Energy Technology Data Exchange (ETDEWEB)

Chamness, Mickie A. [Pacific Northwest National Laboratory

2008-08-29

In 2008, Pacific Northwest National Laboratory evaluated the Hofer Dam fish screen and provided technical assistance at two other fish passage sites as requested by the Bonneville Power Administration, the Walla Walla Watershed Council, or the Confederated Tribes of the Umatilla Indian Reservation. Evaluation of new sites such as Hofer Dam focuses on their design, construction, operation, and maintenance to determine if they effectively provide juvenile salmonids with safe passage through irrigation diversions. There were two requests for technical assistance in 2008. In the first, the Confederated Tribes of the Umatilla Indian Reservation requested an evaluation of the Nursery Bridge fish screens associated with the fish ladder on the east side of the Walla Walla River. One set of brushes that clean the screens was broken for an extended period. Underwater videography and water velocity measurements were used to determine there were no potential adverse effects on juvenile salmonids when the west set of screens was clean enough to pass water normally. A second request, received from the National Marine Fisheries Service and the Walla Walla Watershed Council, asked for evaluation of water velocities through relatively new head gates above and adjacent to the Eastside Ditch fish screens on the Walla Walla River. Water moving through the head gates and not taken for irrigation is diverted to provide water for the Nursery Bridge fish ladder on the east side of the river. Elevations used in the design of the head gates were incorrect, causing excessive flow through the head gates that closely approached or exceeded the maximum swimming burst speed of juvenile salmonids. Hofer Dam was evaluated in June 2008. PNNL researchers found that conditions at Hofer Dam will not cause impingement or entrainment of juvenile salmonids but may provide habitat for predators and lack strong sweeping flows to encourage juvenile salmonid passage downstream. Further evaluation of

Development of a System-Wide Predator Control Program: Stepwise Implementation of a Predation Index, Predator Control Fisheries, and Evaluation Plan in the Columbia River Basin; Northern Pikeminnow Management Program, 2001 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Porter, Russell G.; Winther, Eric C.; Fox, Lyle G.

2003-03-01

This report presents results for year eleven in a basin-wide program to harvest northern pikeminnow (Ptychocheilus oregonensis). This program was started in an effort to reduce predation by northern pikeminnow on juvenile salmonids during their emigration from natal streams to the ocean. Earlier work in the Columbia River Basin suggested predation by northern pikeminnow on juvenile salmonids might account for most of the 10-20% mortality juvenile salmonids experience in each of eight Columbia River and Snake River reservoirs. Modeling simulations based on work in John Day Reservoir from 1982 through 1988 indicated that, if predator-size northern pikeminnow were exploited at a 10-20% rate, the resulting restructuring of their population could reduce their predation on juvenile salmonids by 50%. To test this hypothesis, we implemented a sport-reward angling fishery and a commercial longline fishery in the John Day Pool in 1990. We also conducted an angling fishery in areas inaccessible to the public at four dams on the mainstem Columbia River and at Ice Harbor Dam on the Snake River. Based on the success of these limited efforts, we implemented three test fisheries on a system-wide scale in 1991--a tribal longline fishery above Bonneville Dam, a sport-reward fishery, and a dam-angling fishery. Low catch of target fish and high cost of implementation resulted in discontinuation of the tribal longline fishery. However, the sport-reward and dam-angling fisheries were continued in 1992 and 1993. In 1992, we investigated the feasibility of implementing a commercial longline fishery in the Columbia River below Bonneville Dam and found that implementation of this fishery was also infeasible.

Behavioural and Neuroendocrine Effects of Stress in Salmonid Fish

OpenAIRE

Øverli, Øyvind

2001-01-01

Stress can affect several behavioural patterns, such as food intake and the general activity level of an animal. The central monoamine neurotransmitters serotonin, dopamine, and norepinephrine are important in the mediation of both behavioural and neuroendocrine stress effects. This thesis describes studies of two salmonid fish model systems: Fish that become socially dominant or subordinate when reared in pairs, and rainbow trout (Oncorhynchus mykiss) genetically selected for high (HR) and l...

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...

Job satisfaction in the shrimp trawl fisheries of Chennai, India

OpenAIRE

Bavinck, M.

2012-01-01

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...

Juvenile coho salmon growth and health in streams across an urbanization gradient

Science.gov (United States)

Spanjer, Andrew R.; Moran, Patrick W.; Larsen, Kimberly; Wetzel, Lisa; Hansen, Adam G.; Beauchamp, David A.

2018-01-01

Expanding human population and urbanization alters freshwater systems through structural changes to habitat, temperature effects from increased runoff and reduced canopy cover, altered flows, and increased toxicants. Current stream assessments stop short of measuring health or condition of species utilizing these freshwater habitats and fail to link specific stressors mechanistically to the health of organisms in the stream. Juvenile fish growth integrates both external and internal conditions providing a useful indicator of habitat quality and ecosystem health. Thus, there is a need to account for ecological and environmental influences on fish growth accurately. Bioenergetics models can simulate changes in growth and consumption in response to environmental conditions and food availability to account for interactions between an organism's environmental experience and utilization of available resources. The bioenergetics approach accounts for how thermal regime, food supply, and food quality affect fish growth. This study used a bioenergetics modeling approach to evaluate the environmental factors influencing juvenile coho salmon growth among ten Pacific Northwest streams spanning an urban gradient. Urban streams tended to be warmer, have earlier emergence dates and stronger early season growth. However, fish in urban streams experienced increased stress through lower growth efficiencies, especially later in the summer as temperatures warmed, with as much as a 16.6% reduction when compared to fish from other streams. Bioenergetics modeling successfully characterized salmonid growth in small perennial streams as part of a more extensive monitoring program and provides a powerful assessment tool for characterizing mixed life-stage specific responses in urban streams.

Expert initial review of Columbia River Basin salmonid management models: Summary report

International Nuclear Information System (INIS)

Barnthouse, L.W.

1993-10-01

Over the past years, several fish passage models have been developed to examine the downstream survival of salmon during their annual migration through the Columbia River reservoir system to below Bonneville Dam. More recently, models have been created to simulate the survival of salmon throughout the entire life cycle. The models are used by various regional agencies and native American tribes to assess impacts of dam operation, harvesting, and predation on salmonid abundance. These models are now also being used to assess extinction probabilities and evaluate restoration alternatives for threatened and endangered salmonid stocks. Oak Ridge National Laboratory (ORNL) coordinated an initial evaluation of the principal models by a panel of outside, expert reviewers. None of the models were unequivocally endorsed by any reviewer. Significant strengths and weaknesses were noted for each with respect to reasonability of assumptions and equations, adequacy of documentation, adequacy of supporting data, and calibration procedures. Although the models reviewed differ in some important respects, all reflect a common conceptual basis in classical population dynamic theory and a common empirical basis consisting of the available time series of salmonid stock data, hydrographic records, experimental studies of dam passage parameters, and measurements of reservoir mortality. The results of this initial review are not to be construed as a comprehensive scientific peer review of existing Columbia River Basin (CRB) salmon population models and data. The peer review process can be enhanced further by a dynamic exchange regional modelers and scientific panel experts involving interaction and feedback

Effects of river morphology, hydraulic gradients, and sediment deposition on water exchange and oxygen dynamics in salmonid redds.

Science.gov (United States)

Schindler Wildhaber, Y; Michel, C; Epting, J; Wildhaber, R A; Huber, E; Huggenberger, P; Burkhardt-Holm, P; Alewell, C

2014-02-01

Fine sediment decreasing gravel permeability and oxygen supply to incubating salmonid embryos, is often considered the main contributing factor for the observed decline of salmonid populations. However, oxygen supply to salmonid embryos also depends on hydraulic conditions driving water flow through the redd. A more generalized perspective is needed to better understand the constraints on successful salmonid incubation in the many heavily modified fluvial ecosystems of the Northern Hemisphere. The effects of hydraulic gradients, riverbed and redd morphology as well as fine sediment deposition on dissolved oxygen (DO) and water exchange was studied in 18 artificial redds at three sites along a modified river. Fifty percent of the redds in the two downstream sites were lost during high flow events, while redd loss at the upstream site was substantially lower (8%). This pattern was likely related to increasing flood heights from up- to downstream. Specific water infiltration rates (q) and DO were highly dynamic and driven on multiple temporal and spatial scales. Temporally, the high permeability of the redd gravel and the typical pit-tail structure of the new built redds, leading to high DO, disappeared within a month, when fine sediment had infiltrated and the redd structure was leveled. On the scale of hours to days, DO concentrations and q increased during high flows, but decreased during the falling limb of the water level, most likely related to exfiltration of oxygen depleted groundwater or hyporheic water. DO concentrations also decreased under prolonged base flow conditions, when increased infiltration of silt and clay particles clogged the riverbed and reduced q. Spatially, artificial log steps affected fine sediment infiltration, q and interstitial DO in the redds. The results demonstrate that multiple factors have to be considered for successful river management in salmonid streams, including riverbed structure and local and regional hydrogeological

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...

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....

A protocol using coho salmon to monitor Tongass National Forest Land and Resource Management Plan standards and guidelines for fish habitat.

Science.gov (United States)

M.D. Bryant; Trent McDonald; R. Aho; B.E. Wright; Michelle Bourassa Stahl

2008-01-01

We describe a protocol to monitor the effectiveness of the Tongass Land Management Plan (TLMP) management standards for maintaining fish habitat. The protocol uses juvenile coho salmon (Oncorhynchus kisutch) in small tributary streams in forested watersheds. We used a 3-year pilot study to develop detailed methods to estimate juvenile salmonid...

The effect of chlorpyrifos on salinity acclimation of juvenile rainbow trout (Oncorhynchus mykiss).

Science.gov (United States)

Amiri, Bagher Mojazi; Xu, Elvis Genbo; Kupsco, Allison; Giroux, Marissa; Hoseinzadeh, Mahbubeh; Schlenk, Daniel

2018-02-01

As a part of their unique life cycle, most salmonids undergo a transition from fresh water to salt water requiring various adjustments in metabolism, osmoregulation and ion regulation. Exposure to pesticides may affect the acclimation of juvenile salmonids to salt water during downstream migration to estuaries. Using the Caspian Sea as a model waterbody, the present study aimed to determine how the toxicity of the organophosphate pesticide chlorpyrifos (CPF) impacts saline acclimation of rainbow trout (Oncorhynchus mykiss). We pre-exposed 4-month-old fish to nominal concentrations of 0, 20, 40, 80, 160 μg/L of CPF for seven days, and then gradually to salinity (12 ppt) for another seven days. Mortality, levels of cortisol, T3 and T4 in serum, and expression of genes involved in gill ion transport (Na + /K + ATPase α1a and α1b) and liver xenobiotic detoxification (Glutathione-S-Transferase pi, GST) were measured at day fourteen. Cortisol concentrations in serum were not changed by CPF exposure in freshwater, but serum T3 increased up to three fold relative to controls in freshwater. Following salinity acclimation, T3 and T4 concentrations in the serum were both increased up to 2.5 and 8.8 fold in animals treated with CPF followed by saltwater. Na+/K + ATPase α1a and α1b mRNA in gill were unchanged by CPF treatment in freshwater but trended higher in CPF-treated animals after salinity acclimation. Hepatic mRNA of GST was significantly increased following exposure to CPF but was unchanged after saltwater exposure. Although saltwater treatment reduced the acute lethality of CPF, changes in T3/T4 suggest sublethal impacts may occur in CPF-treated fish after they acclimate to Caspian seawater. Copyright © 2017 Elsevier B.V. All rights reserved.

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

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

Feeding Activity, Rate of Consumption, Daily Ration and Prey Selection of Major Predators in John Day Reservoir, 1985: Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Palmer, Douglas E.; United States. Bonneville Power Administration; U.S. Fish and Wildlife Service; National Fishery Research Center (U.S.)

1986-10-01

This report summarizes activities in 1985 to determine the extent of predation on juvenile salmonids in John Day Reservoir. To estimate consumption of juvenile salmonids we used the composition of the natural diet of predators and in the laboratory determined rate of gastric evacuation by predators. Salmonids were the single most important food item for northern squawfish (Ptychocheilus oregonensis) at McNary tailrace during all sampling periods and at John Day forebay during July. Salmonids accounted for 11.6% of the diet of walleye (Stizostedion vitreum vitreum) in 1985 which was about twice that found in previous years. Salmonids contributed little to smallmouth bass (Micropterus dolomieui) diet but comprised about 25% of the diet of channel catfish (Ictalurus punctatus). Composition of prey taxa in beach seine catches in 1985 was similar to 1983 and 1984 with chinook salmon (Oncorhynchus tschawytscha), northern squawfish, largescale sucker (Catostomus macrocheilus), and sand roller (Percopsis transmontana) dominating the catch at main channel stations and crappies (Pomoxis spp.) and largescale sucker dominating at backwater stations. Preliminary results of beach seine efficiency studies suggest that seine efficiency varied significantly among prey species and between substrate types in 1985. Results of digestion rate experiments indicate that gastric evacuation in northern squawfish can be predicted using water temperature, prey weight, predator weight and time. 19 refs., 19 figs., 13 tabs.

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

Recent stock assessments of the Pandalus stock in the Skagerrak (ICES Division IIIa) and the Norwegian Deep (Division IVa east) have relied largely on a time-series of landings per unit effort (lpue) calculated from Danish logbook data. Because of fleet renewal and trawl-size changes, the relatio......Recent stock assessments of the Pandalus stock in the Skagerrak (ICES Division IIIa) and the Norwegian Deep (Division IVa east) have relied largely on a time-series of landings per unit effort (lpue) calculated from Danish logbook data. Because of fleet renewal and trawl-size changes...

A synthesis of tagging studies examining the behaviour and survival of anadromous salmonids in marine environments.

Directory of Open Access Journals (Sweden)

S Matthew Drenner

Full Text Available This paper synthesizes tagging studies to highlight the current state of knowledge concerning the behaviour and survival of anadromous salmonids in the marine environment. Scientific literature was reviewed to quantify the number and type of studies that have investigated behaviour and survival of anadromous forms of Pacific salmon (Oncorhynchus spp., Atlantic salmon (Salmo salar, brown trout (Salmo trutta, steelhead (Oncorhynchus mykiss, and cutthroat trout (Oncorhynchus clarkii. We examined three categories of tags including electronic (e.g. acoustic, radio, archival, passive (e.g. external marks, Carlin, coded wire, passive integrated transponder [PIT], and biological (e.g. otolith, genetic, scale, parasites. Based on 207 papers, survival rates and behaviour in marine environments were found to be extremely variable spatially and temporally, with some of the most influential factors being temperature, population, physiological state, and fish size. Salmonids at all life stages were consistently found to swim at an average speed of approximately one body length per second, which likely corresponds with the speed at which transport costs are minimal. We found that there is relatively little research conducted on open-ocean migrating salmonids, and some species (e.g. masu [O. masou] and amago [O. rhodurus] are underrepresented in the literature. The most common forms of tagging used across life stages were various forms of external tags, coded wire tags, and acoustic tags, however, the majority of studies did not measure tagging/handling effects on the fish, tag loss/failure, or tag detection probabilities when estimating survival. Through the interdisciplinary application of existing and novel technologies, future research examining the behaviour and survival of anadromous salmonids could incorporate important drivers such as oceanography, tagging/handling effects, predation, and physiology.

Juvenile Chinook Salmon mortality in a Snake River Reservoir: Smallmouth Bass predation revisited

Science.gov (United States)

Erhardt, John M.; Tiffan, Kenneth F.; Connor, William P.

2018-01-01

Predation by nonnative fishes has been identified as a contributing factor in the decline of juvenile salmonids in the Columbia River basin. We examined the diet composition of Smallmouth Bass Micropterus dolomieu and estimated the consumption and predation loss of juvenile Chinook Salmon Oncorhynchus tshawytscha in Lower Granite Reservoir on the Snake River. We examined 4,852 Smallmouth Bass stomachs collected from shoreline habitats during April–September 2013–2015. Chinook Salmon were the second most commonly consumed fish by all size‐classes of Smallmouth Bass (≥150 mm TL) throughout the study. Over the 3 years studied, we estimated that a total of 300,373 Chinook Salmon were consumed by Smallmouth Bass in our 22‐km study area, of which 97% (291,884) were subyearlings (age 0) based on length frequency data. A majority of the loss (61%) occurred during June, which coincided with the timing of hatchery releases of subyearling fall Chinook Salmon. Compared to an earlier study, mean annual predation loss increased more than 15‐fold from 2,670 Chinook Salmon during 1996–1997 to 41,145 Chinook Salmon during 2013–2015 (in reaches that could be compared), despite lower contemporary Smallmouth Bass abundances. This increase can be explained in part by increases in Smallmouth Bass consumption rates, which paralleled increases in subyearling Chinook Salmon densities—an expected functional response by an opportunistic consumer. Smallmouth Bass are currently significant predators of subyearling Chinook Salmon in Lower Granite Reservoir and could potentially be a large source of unexplained mortality.

50 CFR Figure 6 to Part 223 - TED Extension in Summer Flounder Trawl

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false TED Extension in Summer Flounder Trawl 6 Figure 6 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS THREATENED MARINE AND ANADROMOUS SPECIES Pt. 223, Fig. 6 Figure 6 to Part 223—TED...

Juvenile rheumatoid arthritis

Science.gov (United States)

... joints. This form of JIA may turn into rheumatoid arthritis. It may involve 5 or more large and ... no known prevention for JIA. Alternative Names Juvenile rheumatoid arthritis (JRA); Juvenile chronic polyarthritis; Still disease; Juvenile spondyloarthritis ...

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...

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...

Influences of Stocking Salmon Carcass Analogs on Salmonids in Klickitat River Tributaries, 2001-2005 Completion Report.

Energy Technology Data Exchange (ETDEWEB)

Zendt, Joe; Sharp, Bill (Yakama Nation Fisheries, Toppenish, WA)

2006-09-01

This report describes the work completed by the Yakama Nation Fisheries Program (YNFP) in the Klickitat subbasin in south-central Washington under BPA innovative project No.200105500--Influences of stocking salmon carcass analogs on salmonids in Columbia River Tributaries. Salmon carcasses historically provided a significant source of marine-derived nutrients to many stream systems in the Columbia basin, and decreased run sizes have led to a loss of this nutrient source in many streams. Partners in this project developed a pathogen-free carcass analog and stocked the analogs in streams with the following objectives: restoring food availability to streams with reduced anadromous salmon returns; mimicking the natural pathways and timing of food acquisition by salmonids; minimizing unintended negative ecological effects; and increasing the growth and survival of salmonids. In the Klickitat subbasin, carcass analogs were stocked in two streams in 2002 and 2003; a third stream was used as a control. Salmonid fish abundance, growth, and stomach contents were monitored in all three streams before and after carcass analog placement. Fish, invertebrate, and periphyton samples were also collected for stable isotope analysis (to determine if nutrients from carcass analogs were incorporated into the stream food web). Water quality samples were also collected to determine if nutrient overloading occurred in streams. Significant differences in growth were found between fish in treated and untreated stream reaches. Fish in treatment reaches exhibited higher instantaneous growth rates approximately one month after the first carcass analog stocking. Stomach contents sampling indicated that salmonid fish routinely consumed the carcass analog material directly, and that stomach fullness of fish in treatment reaches was higher than in untreated reaches in the first few weeks following carcass analog stockings. No significant differences were detected in fish abundance between

Status after 5 Years of Survival Compliance Testing in the Federal Columbia River Power System (FCRPS)

Energy Technology Data Exchange (ETDEWEB)

Skalski, John R.; Weiland, Mark A.; Ham, Kenneth D.; Ploskey, Gene R.; McMichael, Geoffrey A.; Colotelo, Alison H.; Carlson, Thomas J.; Woodley, Christa M.; Eppard, M. Brad; Hockersmith, Eric E.

2016-06-27

Survival studies of juvenile salmonids implanted with acoustic tags have been conducted at hydroelectric dams within the Federal Columbia River Power System (FCRPS) in the Columbia and Snake rivers between 2010 and 2014 to assess compliance with dam passage survival standards stipulated in the 2008 Biological Opinion (BiOp). For juvenile salmonids migrating downstream in the spring, dam passage survival defined as survival from the upstream dam face to the tailrace mixing zone must be ≥96% and for summer migrants, ≥93%, and estimated with a standard error ≤1.5% (i.e., 95% confidence interval of ±3%). A total of 29 compliance tests have been conducted at 6 of 8 FCRPS main-stem dams, using over 109,000 acoustic-tagged salmonid smolts. Of these 29 compliance studies, 23 met the survival standards and 26 met the precision requirements. Of the 6 dams evaluated to date, individual survival estimates range from 0.9597 to 0.9868 for yearling Chinook Salmon, 0.9534 to 0.9952 for steelhead, and 0.9076 to 0.9789 for subyearling Chinook Salmon. These investigations suggest the large capital investment over the last 20 years to improve juvenile salmon passage through the FCRPS dams has been beneficial.

78 FR 7371 - Fisheries Off West Coast States; Pacific Coast Groundfish Fishery; Trawl Rationalization Program...

Science.gov (United States)

2013-02-01

... Rationalization Program; Cost Recovery AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... Office rule goes final before the cost recovery program rule and if it would affect the appeals process... would implement a cost recovery program for the Pacific coast groundfish trawl rationalization program...

PCR-RFLP Method to Identify Salmonid Species of Economic Importance

Directory of Open Access Journals (Sweden)

Andreea Dudu

2011-05-01

Full Text Available The identification of different fish species by molecular methods has become necessary to avoid both the incorrect labelling of individuals involved in repopulation programmes and the commercial frauds on the fish market. Different fish species of great economical importance, like the salmonids, which are very much requested for their meat, can be identified using molecular techniques such as PCR-RFLP. The method is based on the amplification of a target region from the genome by PCR reaction followed by endonucleases digestion to detect the polymorphism of restriction fragments. In our study we analysed the following salmonid species from Romania: Salmo trutta fario, Salmo labrax, Salvelinus fontinalis, Onchorhynchus mykiss, Thymallus thymallus and Hucho hucho. In order to discriminate between the analysed species we amplified a fragment of mitochondrial genome comprising tRNAGlu/ cytochrome b/ tRNAThr/ tRNAPro/ D-loop/ tRNAPhe, followed by digestion with a specific restriction enzyme. The direct digestion of unpurified PCR products generated species-specific restriction patterns and proved to be a simple, reliable, inexpensive and fast method. Thus, it may be successfully utilized in specialized laboratories for the correct identification of the fish species for multiple purposes, including the traceability of fish food products.

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.

Persistence of Salmonid Redds

Science.gov (United States)

Buffington, J. M.; Buxton, T.; Fremier, A. K.; Hassan, M. A.; Yager, E.

2013-12-01

The construction of redds by spawning salmonids modifies fluvial processes in ways that are beneficial to egg and embryo survival. Redd topography induces hyporheic flow that oxygenates embryos incubating within the streambed and creates form drag that reduces bed mobility and scour of salmonid eggs. Winnowing of fine material during redd construction also coarsens the streambed, increasing bed porosity and hyporheic flow and reducing bed mobility. In addition to the biological benefits, redds may influence channel morphology by altering channel hydraulics and bed load transport rates depending on the size and extent of redds relative to the size of the channel. A key question is how long do the physical and biological effects of redds last? Field observations indicate that in some basins redds are ephemeral, with redd topography rapidly erased by subsequent floods, while in other basins, redds can persist for years. We hypothesize that redd persistence is a function of basin hydrology, sediment supply, and characteristics of the spawning fish. Hydrology controls the frequency and magnitude of bed mobilizing flows following spawning, while bed load supply (volume and caliber) controls the degree of textural fining and consequent bed mobility after spawning, as well as the potential for burial of redd features. The effectiveness of flows in terms of their magnitude and duration depend on hydroclimate (i.e., snowmelt, rainfall, or transitional hydrographs), while bed load supply depends on basin geology, land use, and natural disturbance regimes (e.g., wildfire). Location within the stream network may also influence redd persistence. In particular, lakes effectively trap sediment and regulate downstream flow, which may promote long-lived redds in stream reaches below lakes. These geomorphic controls are modulated by biological factors: fish species (size of fish controls size of redds and magnitude of streambed coarsening); life history (timing of spawning and

Otter trawls in Greece: Landing profiles and potential mιtiers

Directory of Open Access Journals (Sweden)

S. KATSANEVAKIS

2010-02-01

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.

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

both negatively and positively influence the quantity and quality of food available. Using δ 13C and δ 15N we investigated potential diet changes of three commercially exploited species across trawling gradients in the Kattegat (plaice, dab and Norway lobster (Nephrops)) and the Irish Sea (Nephrops...

Development of a System wide Predator Control Program: Stepwise Implementation of a Predation Index, Predator Control Fisheries, and Evaluation Plan in the Columbia River Basin; Section II: Evaluation; 1996 Annual Report

International Nuclear Information System (INIS)

Young, Franklin R.

1997-01-01

Predator control fisheries aimed at reducing predation on juvenile salmonids by northern squawfish (Ptychocheilus oregonensis) were implemented for the seventh consecutive year in the mainstream Columbia and Snake rivers

Assessment of Salmonids and their Habitat Conditions in the Walla Walla River Basin within Washington, 2001 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Mendel, Glen Wesley; Trump, Jeremy; Karl, David

2002-12-01

Concerns about the decline of native salmon and trout populations have increased among natural resource managers and the public in recent years. As a result, a multitude of initiatives have been implemented at the local, state, and federal government levels. These initiatives include management plans and actions intended to protect and restore salmonid fishes and their habitats. In 1998 bull trout (Salvelinus confluentus) were listed under the Endangered Species Act (ESA), as ''Threatened'', for the Walla Walla River and its tributaries. Steelhead (Oncorhynchus mykiss) were listed as ''Threatened'' in 1999 for the mid-Columbia River and its tributaries. These ESA listings emphasize the need for information about these threatened salmonid populations and their habitats. The Washington Department of Fish and Wildlife (WDFW) is entrusted with ''the preservation, protection, and perpetuation of fish and wildlife....[and to] maximize public recreational or commercial opportunities without impairing the supply of fish and wildlife (WAC 77.12.010).'' In consideration of this mandate, the WDFW submitted a proposal in December 1997 to the Bonneville Power Administration (BPA) for a study to assess salmonid distribution, relative abundance, genetics, and the condition of salmonid habitats in the Walla Walla River basin. The primary purposes of this project are to collect baseline biological and habitat data, to identify major data gaps, and to draw conclusions whenever possible. The study reported herein details the findings of the 2001 field season (March to November, 2001).

Conceptualizing juvenile prostitution as child maltreatment: findings from the National Juvenile Prostitution Study.

Science.gov (United States)

Mitchell, Kimberly J; Finkelhor, David; Wolak, Janis

2010-02-01

Two studies were conducted to identify the incidence (Study 1) and characteristics (Study 2) of juvenile prostitution cases known to law enforcement agencies in the United States. Study 1 revealed a national estimate of 1,450 arrests or detentions (95% confidence interval [CI]: 1,287-1,614) in cases involving juvenile prostitution during a 1-year period. In Study 2, exploratory data were collected from a subsample of 138 cases from police records in 2005. The cases are broadly categorized into three main types: (a) third-party exploiters, (b) solo prostitution, and (c) conventional child sexual abuse (CSA) with payment. Cases were classified into three initial categories based on police orientation toward the juvenile: (a) juveniles as victims (53%), (b) juveniles as delinquents (31%), and (c) juvenile as both victims and delinquents (16%). When examining the status of the juveniles by case type, the authors found that all the juveniles in CSA with payment cases were treated as victims, 66% in third-party exploiters cases, and 11% in solo cases. Findings indicate law enforcement responses to juvenile prostitution are influential in determining whether such youth are viewed as victims of commercial sexual exploitation or as delinquents.

Lower Columbia River and Estuary Habitat Monitoring Study, 2011 - Final Report

Energy Technology Data Exchange (ETDEWEB)

Borde, Amy B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kaufmann, Ronald M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cullinan, Valerie I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zimmerman, Shon A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Thom, Ronald M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wright, Cynthia L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2012-03-01

The Ecosystem Monitoring Program is a collaborative effort between the Lower Columbia River Estuary Partnership (LCREP), University of Washington, Wetland Ecosystem Team (UW), US Geological Survey, Water Science Center (USGS), National Oceanic and Atmospheric Administration, National Marine Fisheries Service (NOAA-Fisheries, hereafter NOAA), and Pacific Northwest National Laboratory, Marine Sciences Laboratory (PNNL). The goal of the program is to conduct emergent wetland monitoring aimed at characterizing salmonid habitats in the lower Columbia River and estuary (LCRE) from the mouth of the estuary to Bonneville Dam (Figure 1). This is an ecosystem based monitoring program focused on evaluating status and trends in habitat and reducing uncertainties regarding these ecosystems to ultimately improve the survival of juvenile salmonids through the LCRE. This project comprehensively assesses habitat, fish, food web, and abiotic conditions in the lower river, focusing on shallow water and vegetated habitats used by juvenile salmonids for feeding, rearing and refugia. The information is intended to be used to guide management actions associated with species recovery, particularly that of threatened and endangered salmonids. PNNL’s role in this multi-year study is to monitor the habitat structure (e.g., vegetation, topography, channel morphology, and sediment type) as well as hydrologic patterns.

Comparison of gill nets and fixed-frame trawls for sampling threadfin shad in tropical reservoirs

Czech Academy of Sciences Publication Activity Database

Prchalová, Marie; Neal, J. W.; Munoz-Hincapie, M.; Jůza, Tomáš; Říha, Milan; Peterka, Jiří; Kubečka, Jan

2012-01-01

Roč. 141, č. 4 (2012), s. 1151-1160 ISSN 0002-8487 R&D Projects: GA ČR(CZ) GPP505/12/P647 Institutional support: RVO:60077344 Keywords : threadfin shad * gillnet * trawl * gear selectivity * catchability * reservoir Subject RIV: EH - Ecology, Behaviour Impact factor: 1.546, year: 2012

Great lakes prey fish populations: a cross-basin overview of status and trends based on bottom trawl surveys, 1978-2012

Science.gov (United States)

Gorman, Owen T.

2012-01-01

The assessment of prey fish stocks in the Great Lakes have been conducted annually with bottom trawls since the 1970s by the Great Lakes Science Center, sometimes assisted by partner agencies. These stock assessments provide data on the status and trends of prey fish that are consumed by important commercial and recreational fishes. Although all these annual surveys are conducted using bottom trawls, they differ among the lakes in the proportion of the lake covered, seasonal timing, bottom trawl gear used, and the manner in which the trawl is towed (across or along bottom contours). Because each assessment is unique in one or more important aspects, direct comparison of prey fish catches among lakes is not straightforward. However, all of the assessments produce indices of abundance or biomass that can be standardized to facilitate comparisons of status and trends across all the Great Lakes. In this report, population indices were standardized to the highest value for a time series within each lake for the following principal prey species: cisco (Coregonus artedi), bloater (C. hoyi), rainbow smelt (Osmerus mordax), and alewife (Alosa pseudoharengus). Indices were also provided for round goby (Neogobius melanostomus), an invasive fish that has proliferated throughout the basin over the past 18 years. These standardized indices represent the best available long-term indices of relative abundance for these fishes across all of the Great Lakes. In this report, standardized indices are presented in graphical form along with synopses to provide a short, informal cross-basin summary of the status and trends of principal prey fishes. In keeping with this intent, tables, references, and a detailed discussion were omitted.

AFSC/RACE/MACE: Results of 2012 Acoustic-trawl survey of the Shumagin Islands and Sanak Trough dy1201

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...

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

Development of a new method for the determination of residues of the neonictinoid insecticide imidacloprid in juvenile Chinook (Oncorhynchus tyshawytscha) using ELISA detection

Science.gov (United States)

Frew, John A.; Grue, Christian E.

2012-01-01

The neonicotinoid insecticide imidacloprid (IMI) has been proposed as an alternative to carbaryl for controlling indigenous burrowing shrimp on commercial oyster beds in Willapa Bay and Grays Harbor, Washington. A focus of concern over the use of this insecticide in an aquatic environment is the potential for adverse effects from exposure to non-target species residing in the Bay, such as juvenile Chinook (Oncorhynchus tshawytscha) and cutthroat trout (O. clarki). Federal registration and State permiting approval for the use of IMI will require confirmation that the compound does not adversely impact these salmonids following field applications. This will necessitate an environmental monitoring program for evaluating exposure in salmonids following the treatment of beds. Quantification of IMI residues in tissue can be used for determining salmonid exposure to the insecticide. Refinement of an existing protocol using liquid-chromatography mass spectrometry (LC-MS) detection would provide the low limits of quantification, given the relatively small tissue sample sizes, necessary for determining exposure in individual fish. Such an approach would not be viable for the environmental monitoring effort in Willapa Bay and Grays Harbor due to the high costs associated with running multiple analyses, however. A new sample preparation protocol was developed for use with a commercially available enzyme-linked immunosorbent assay (ELISA) for the quantification of IMI, thereby providing a low-cost alternative to LC-MS for environmental monitoring in Willapa Bay and Grays Harbor. Extraction of the analyte from the salmonid brain tissue was achieved by Dounce homogenization in 4.0 mL of 20.0 mM Triton X-100, followed by a 6 h incubation at 50–55 °C. Centrifugal ultrafiltration and reversed phase solid phase extraction were used for sample cleanup. The limit of quantification for an average 77.0 mg whole brain sample was calculated at 18.2 μg kg-1 (ppb) with an average

Metro Multnomah Wetlands - Multnomah Channel Wetland Restoration Monitoring Project

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Multnomah Channel Wetland Restoration Monitoring Project characterizes wetlands use by juvenile salmonids and other fishes in the Multnomah Channel Marsh Natural...

Comparison of infectious hematopoietic necrosis in natural and experimental infections of spawning salmonids by infectivity and immunohistochemistry

Science.gov (United States)

Yamamoto, T.; Arakawa, C.K.; Batts, W.N.; Winton, J.R.

1989-01-01

Infectious hematopoietic necrosis (IHN) continues to be a serious virus disease of salmonids with epizootics recorded in both wild and hatchery populations (Williams and Amend 1976; Carlisle et al 1979; Groberg and Fryer 1983; Saft and Pratt 1986; Traxler 1987; Follett et al 1987; Meyers et al 1988). While originally enzootic in western North America, the virus appears to be spreading further (Sano et al 1977; de Kinkelin et al 1987; Bovo et al 1987). In hatchery outbreaks occurring in regions where the virus is not enzootic, it is often possible to trace the virus to the importation of infected fingerlings or contaminated eggs. In regions where the virus is widespread among stocks of fish, the source of virus infection is more difficult to establish particularly in watersheds where there are anadromous salmonids. Although salmonid fish surviving infection as fry and returning from the ocean to spawn are considered to be parental carriers of IHNV, there is very little data to support this hypothesis. Amend (1975) in the study of rainbow trout reported that in a population surviving infection and assayed a few years later found that a few trout were carrying virus. This is the study often cited as evidence for the carrier status of returning salmonids. LaPatra et al (1987) presented data that indicated IHNV has been transmitted horizontally through water from adult chinook salmon (Oncorhynchus tshawytscha) to adult coho salmon (O. kisutch) at a hatchery in northern California. They suggested that horizontal transmission may be an important means for perpetuating IHN. However, the actual mechanisms for persistence and transmission of IHN among fish in a watershed is likely to be complex and involve multiple species and age groups as well as intermediate vectors and/or reservoirs.

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 ...

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

A framework to assess the impact of mobile fishing gear on the seabed and benthic ecosystem is presented. The framework that can be used at regional and local scales provides indicators for both trawling pressureand ecological impact. It builds on high-resolution maps of trawlingintensity and con...

What Is Juvenile Arthritis?

Science.gov (United States)

... Initiative Breadcrumb Home Health Topics English Español Juvenile Arthritis Basics In-Depth Download Download EPUB Download PDF What is it? Points To Remember About Juvenile Arthritis Juvenile arthritis is the term used to describe ...

Interactions between a Trawl fishery and spatial closures for biodiversity conservation in the Great Barrier Reef World Heritage Area, Australia.

Directory of Open Access Journals (Sweden)

Alana Grech

Full Text Available BACKGROUND: The Queensland East Coast Otter Trawl Fishery (ECOTF for penaeid shrimp fishes within Australia's Great Barrier Reef World Heritage Area (GBRWHA. The past decade has seen the implementation of conservation and fisheries management strategies to reduce the impact of the ECOTF on the seabed and improve biodiversity conservation. New information from electronic vessel location monitoring systems (VMS provides an opportunity to review the interactions between the ECOTF and spatial closures for biodiversity conservation. METHODOLOGY AND RESULTS: We used fishing metrics and spatial information on the distribution of closures and modelled VMS data in a geographical information system (GIS to assess change in effort of the trawl fishery from 2001-2009 and to quantify the exposure of 70 reef, non-reef and deep water bioregions to trawl fishing. The number of trawlers and the number of days fished almost halved between 2001 and 2009 and new spatial closures introduced in 2004 reduced the area zoned available for trawl fishing by 33%. However, we found that there was only a relatively minor change in the spatial footprint of the fishery as a result of new spatial closures. Non-reef bioregions benefited the most from new spatial closures followed by deep and reef bioregions. CONCLUSIONS/SIGNIFICANCE: Although the catch of non target species remains an issue of concern for fisheries management, the small spatial footprint of the ECOTF relative to the size of the GBRWHA means that the impact on benthic habitats is likely to be negligible. The decline in effort as a result of fishing industry structural adjustment, increasing variable costs and business decisions of fishers is likely to continue a trend to fish only in the most productive areas. This will provide protection for most benthic habitats without any further legislative or management intervention.

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

Science.gov (United States)

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

2018-01-01

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

Impact of natural (waves and currents) and anthropogenic (trawl) resuspension on the export of particulate matter to the open ocean: Application to the Gulf of Lion (NW Mediterranean)

Science.gov (United States)

Ferré, B.; Durrieu de Madron, X.; Estournel, C.; Ulses, C.; Le Corre, G.

2008-08-01

Modern sediment deposits on continental margins form a vast reservoir of particulate matter that is regularly affected by resuspension processes. Resuspension by bottom trawling on shelves with strong fishing activity can modify the scale of natural disturbance by waves and currents. Recent field data show that the impact of bottom trawls on fine sediment resuspension per unit surface is comparable with that of the largest storms. We assessed the impact of both natural and anthropogenic processes on the dispersal of riverborne particles and shelf sediments on the Gulf of Lion shelf. We performed realistic numerical simulations of resuspension and transport forced by currents and waves or by a fleet of bottom trawlers. Simulations were conducted for a 16-month period (January 1998-April 1999) to characterise the seasonal variability. The sediment dynamics takes into account bed armoring, ripple geometry and the cohesive and non-cohesive characteristics of the sediments. Essential but uncertain parameters (clay content, erosion fluxes and critical shear stress for cohesive sediment) were set with existing data. Resuspension by waves and currents was controlled by shear stress, whereas resuspension by trawls was controlled by density and distribution of the bottom trawler fleet. Natural resuspension by waves and currents mostly occurred during short seasonal episodes, and was concentrated on the inner shelf. Trawling-induced resuspension, in contrast, occurred regularly throughout the year and was concentrated on the outer shelf. The total annual erosion by trawls (5.6×10 6 t y -1, t for metric tonnes) was four orders of magnitude lower than the erosion induced by waves and currents (35.3×10 9 t y -1). However the net resuspension (erosion/deposition budget) for trawling (0.4×10 6 t y -1) was only one order of magnitude lower than that for waves and currents (9.2×10 6 t y -1). Off-shelf export concerned the finest fraction of the sediment (clays and fine silts

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...

Reflex impairment, physiological stress, and discard mortality of European plaice Pleuronectes platessa in an otter trawl fishery

DEFF Research Database (Denmark)

Methling, Caroline; Skov, Peter Vilhelm; Madsen, Niels

2017-01-01

whether reflex impairment can predict short-term mortality in commercially trawled European plaice upon landing and after air exposure of up to 90 min. Sub-lethal stress was assessed by a suite of physiological variables. Over a 10-day period, mortality was monitored for a total of 199 plaice following...... trawl and air exposure of varying duration, and for 50 control fish scored for reflex impairment on board the vessel. Mortality was only observed in fish exposed to air for >60 min, and averaged 11.1% (95% CI = 7.1–16.3%). Reflex impairment was found to be a significant (P ... of mortality in a generalized linear model, excluding other initially included variables by using a stepwise method. Plasma cortisol, haematocrit, and plasma osmolality all indicated a profound and increasing level of stress with air exposure, accompanied by a near depletion of muscle phosphocreatine...

Temporal and spatial distribution of young Brachyplatystoma spp. (Siluriformes: Pimelodidae) along the rapids stretch of the Madeira River (Brazil) before the construction of two hydroelectric dams.

Science.gov (United States)

Cella-Ribeiro, A; Assakawa, L F; Torrente-Vilara, G; Zuanon, J; Leite, R G; Doria, C; Duponchelle, F

2015-04-01

Monthly (April 2009 to May 2010) bottom-trawl sampling for Brachyplatystoma species along the rapids stretch of the Madeira River in Brazil revealed that Brachyplatystoma rousseauxii larvae and juveniles were present in low abundances in all areas and during all hydrological periods. The presence of larvae and juveniles throughout the hydrological cycle suggests asynchronous spawning in the headwaters of the Madeira River. © 2015 The Fisheries Society of the British Isles.

Juvenile Firesetting.

Science.gov (United States)

Peters, Brittany; Freeman, Bradley

2016-01-01

Juvenile firesetting is a significant cause of morbidity and mortality in the United States. Male gender, substance use, history of maltreatment, interest in fire, and psychiatric illness are commonly reported risk factors. Interventions that have been shown to be effective in juveniles who set fires include cognitive behavior therapy and educational interventions, whereas satiation has not been shown to be an effective intervention. Forensic assessments can assist the legal community in adjudicating youth with effective interventions. Future studies should focus on consistent assessment and outcome measures to create more evidence for directing evaluation and treatment of juvenile firesetters. Copyright © 2016 Elsevier Inc. All rights reserved.

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...

Ictiofauna juvenil de fondos blandos durante la transición de "secas" a lluvias en la costa pacífica de Colombia

Directory of Open Access Journals (Sweden)

Andrés Velasco

2000-03-01

Full Text Available En base a mayores concentraciones de plancton encontradas en la parte sur de la costa pacífica colombiana, se colectó su ictiofauna juvenil en aguas someras (Based on ichthyoplancton research along the southern Pacific coast of Colombia, which revealed high concentrations of fish larvae in this area, a juvenil fish survey was conducted in shallow waters (<10 meter water depth during the transition period from dry to wet season (July 21 to July 31, 1994. The twelve sampling stations, were distributed in front of the four main of this coastline, where the highest concentrations of juvenile fish were expected. At each sample station, three 15 min oblique hauls were conducted every 8 hours using a bottom trawl for juvenile fish of 4 mm mesh size; 53 species in 20 families were identified (21 not known as adults in the area. They were distributed as follows: Sciaenids (11, Ariids (7, Pristigasterids (6, Engraulids (6, Carangids (5, Clupeids (2, Soleids (2, Batrachoidids (2, Tetraodontids (2, Urolophids (1, Polynemids (1, Synodontids (1 and Taeniopedids (1. This ichthyofauna is common in open tropical estuaries. Abundances and biomass were 0.35 ind./m³ and 1.61 g/m³ respectively, higher than in other tropical shallow water systems. The niches of the 25 species whose abundance (A and biomass (B contributed 97.5% and 93.3% respectively to the total catches were: (1 pelagic-neritic (53% A, 34% B; (2 demersal-pelagic (18% A, 28% B; (3 demersal (22% A, 23% B and (4 benthic (8% A, 15% B. The Shannon-Weaver diversity index in the four subareas ranged from 0.89 to 1.1, within the range reported for other tropical American estuarine systems. An ordination analysis (non-metric Multi-Dimensional Scaling, MDS of the data revealed significant differences in the species composition between day and night and an important association among some species. Station position, tides and environmental parameters did not markedly influence species composition. It is

Tabular statistical summay of data analysis - Calawah River Riverscape Study

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The objective of this study was to identify the patterns of juvenile salmonid distribution and relative abundance in relation to habitat correlates. It is the first...

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

Energy Technology Data Exchange (ETDEWEB)

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

1997-08-01

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

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

International Nuclear Information System (INIS)

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

1997-08-01

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

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

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...

Avoidance reactions of fish in the trawl mouth opening in a shallow and turbid lake at night

Czech Academy of Sciences Publication Activity Database

Jůza, Tomáš; Rakowitz, G.; Draštík, Vladislav; Blabolil, Petr; Herzig, A.; Kratochvíl, Michal; Muška, Milan; Říha, Milan; Sajdlová, Zuzana; Kubečka, Jan

2013-01-01

Roč. 147, October (2013), s. 154-160 ISSN 0165-7836 R&D Projects: GA MŠk(CZ) EE2.3.20.0204 Institutional support: RVO:60077344 Keywords : Lake Neusiedl * trawl * DIDSON * fish abundance * biomass Subject RIV: EH - Ecology, Behaviour Impact factor: 1.843, year: 2013

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...

Umatilla River Fish Passage Operations Program, 2002-2003 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Bronson, James P. (Confederated Tribes of the Umatilla Indian Reservation, Department of Natural Resources, Pendleton, OR); Duke, Bill B. (Oregon Department of Fish and Wildlife, Pendleton, OR)

2004-03-01

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 enumerated at Threemile Dam from August 17, 2002 to September 29, 2003. A total of 3,080 summer steelhead (Oncorhynchus mykiss); 1716 adult, 617 jack, and 1,709 subjack fall chinook (O. tshawytscha); 3,820 adult and 971 jack coho (O. kisutch); and 3,607 adult and 135 jack spring chinook (O. tshawytscha) were counted. All fish were enumerated at the east bank facility. Of the fish counted, 6 summer steelhead and 330 adult and 49 jack spring chinook were hauled upstream from Threemile Dam. There were 2,882 summer steelhead; 1161 adult, 509 jack and 1,546 subjack fall chinook; 3,704 adult and 915 jack coho; and 2,406 adult and 31 jack spring chinook either released at, or allowed to volitionally migrate past, Threemile Dam. Also, 109 summer steelhead; 532 adult and 32 jack fall chinook; and 560 adult and 28 jack spring chinook were collected for brood. In addition, 282 spring chinook were collected for the outplanting efforts in the Walla Walla Basin. 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 canal was open for 159 days between January 27 and July 4, 2003. During that period, fish were bypassed back to the river 145 days and were trapped 11 days. An estimated 205 pounds of juvenile fish were transported from Westland to the Umatilla River boat ramp (RM 0.5). Approximately 82% of the juveniles transported were salmonids. No steelhead kelts were hauled from Westland this year. The Threemile Dam west bank juvenile bypass was opened on September 16, 2002. and continued until November 1, 2002. The bypass was reopened March 3, 2003 and ran until July 3, 2003. The juvenile trap was operated by the Umatilla Passage Evaluation

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...

Development of field-based models of suitable thermal regimes for interior Columbia Basin salmonids

Science.gov (United States)

Jason B. Dunham; Bruce Rieman; Gwynne Chandler

2001-01-01

This report describes results of research sponsored through an interagency agreement between the U.S. Forest Service Rocky Mountain Research Station and U.S. Environmental Protection Agency (Interagency Agreement #00-IA-11222014-521). The primary objectives of this research included 1) develop models relating occurrence of two threatened inland salmonid fishes to...

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

Patterns of coho salmon size and survival within a stream network

Science.gov (United States)

Effective habitat restoration planning requires correctly anticipating demographic responses to altered habitats. Network-scale investigations of habitat-specific growth and survival of juvenile salmonids have provided critical insights that can now better inform and help priori...

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...

AFSC/RACE/MACE: Results of 2013 Acoustic-trawl survey of the Shumagin Islands, Sanak Trough, and Morzhovoi Bay dy1302

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...

Juvenile Court Statistics - 1972.

Science.gov (United States)

Office of Youth Development (DHEW), Washington, DC.

This report is a statistical study of juvenile court cases in 1972. The data demonstrates how the court is frequently utilized in dealing with juvenile delinquency by the police as well as by other community agencies and parents. Excluded from this report are the ordinary traffic cases handled by juvenile court. The data indicate that: (1) in…

Juvenile Court Statistics, 1974.

Science.gov (United States)

Corbett, Jacqueline; Vereb, Thomas S.

This report presents information on juvenile court processing of youth in the U.S. during 1974. It is based on data gathered under the National Juvenile Court Statistical Reporting System. Findings can be summarized as follows: (1) 1,252,700 juvenile delinquency cases, excluding traffic offenses, were handled by courts in the U.S. in 1974; (2) the…

Facultative anadromy in salmonids: linking habitat, individual life history decisions, and population-level consequences

Science.gov (United States)

Steven F. Railsback; Bret C. Harvey; Jason L. White

2014-01-01

Modeling and management of facultative anadromous salmonids is complicated by their ability to select anadromous or resident life histories. Conventional theory for this behavior assumes individuals select the strategy offering highest expected reproductive success but does not predict how population-level consequences such as a stream’s smolt production emerge from...

THE STUDY OF FEATURES OF GUILT OF JUVENILE OFFENDERS IN THE CONTEXT OF JUVENILE JUSTICE

Directory of Open Access Journals (Sweden)

Natalija Vladimirovna Galkina

2015-08-01

Full Text Available The article is devoted to the results of empirical studies of the experiences of guilt of juvenile offenders in the context of juvenile justice where a minor appears as the subject of legal relations. Restorative approach of juvenile justice is based on an admission of guilt to the victim. In connection with it, the research of features of the guilt of minors who have committed an offence and the conditions for the development of the subjectivity will enhance understanding of the possibilities of restorative juvenile justice system in the prevention of juvenile delinquency.Thus, the results of empirical research presented in the article are important for determining of the psychological bases of realization of rehabilitation programs in the context of juvenile justice. In particular, the results are important for the organization and conduct of psychological work to overcome the psychological barriers in the behavior of juveniles having inherently maladaptive guilt and destructive psychological defense mechanisms.

Juvenile Justice in Mexico

Directory of Open Access Journals (Sweden)

Martha Frías Armenta

2014-08-01

Full Text Available The first tribunal in Mexico was established in the central state of San Luis Potosi in 1926. The Law Regarding Social Prevention and Juvenile Delinquency for the Federal District and Mexican territories was promulgated in 1928. In 2005, Article 18 of the Mexican Constitution was modified to establish a comprehensive system (“Sistema Integral de justicia” in Spanish of justice for juveniles between 12 and 18 years old who had committed a crime punishable under criminal law. Its objective was to guarantee juveniles all the due process rights established for adults, in addition to the special ones recognized for minors. The constitutional reform also provides a framework that includes special tribunals as well as alternative justice options for juveniles. With these reforms, institutionalization of minors was to be considered an extreme measure applicable only to felonies and to juveniles older than 14. In 2006, all states within the Mexican federation enacted the “Law of justice for adolescents”. This system, at both the federal and state levels, formalizes a new global paradigm with regard to the triangular relationship between children, the State and the Law. It recognizes that children are also bearers of the inherent human rights recognized for all individuals, instead of simply objects in need of protection. However, despite formally aligning Mexican juvenile justice law with the Convention on the Rights of the Child (CRC, issues of actual substantive rights remained and new ones have appeared. For example, juveniles younger than 14 who have not committed a felony are released from institutions without any rehabilitation or treatment options, and alternative forms of justice were included without evaluating their possibilities of application or their conditions for success. In addition, the economic status of most juvenile detainees continues to be one of the most important determining factors in the administration of justice

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...

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...

Common sole in the northern and central Adriatic Sea: Spatial management scenarios to rebuild the stock

Science.gov (United States)

Scarcella, Giuseppe; Grati, Fabio; Raicevich, Saša; Russo, Tommaso; Gramolini, Roberto; Scott, Robert D.; Polidori, Piero; Domenichetti, Filippo; Bolognini, Luca; Giovanardi, Otello; Celić, Igor; Sabatini, Laura; Vrgoč, Nedo; Isajlović, Igor; Marčeta, Bojan; Fabi, Gianna

2014-05-01

The northern and central Adriatic Sea represents an important spawning and aggregation area for common sole (Solea solea) and provides for around 20% of the Mediterranean landings. In this area, this resource is mainly exploited with rapido trawl and set nets. The stock is not yet depleted and faces a situation of growth overfishing. The comparison between the spatial distribution by age of S. solea and the geographic patterns of the rapido trawl fishing effort evidenced an overlapping of this fishing activity with the area where juveniles concentrate (age groups 0-2). The majority of spawners inhabits specific offshore areas, here defined as ‘sole sanctuaries', where high concentrations of debris and benthic communities make difficult trawling with rapido. The aim of this study was to evaluate existing spatial management regimes and potential new spatial and temporal closures in the northern and central Adriatic Sea using a simple modelling tool. Two spatial simulations were carried out in order to verify the effectiveness of complementary methods for the management of fisheries: the ban of rapido trawling from October to December within 6 nautical miles and 9 nautical miles of the Italian coast. The focus of the simulation is that the effort of the rapido trawl is moved far from the coast during key sole recruitment periods, when the juveniles are moving from the inshore nursery area toward the offshore feeding grounds. The management scenarios showed that a change in selectivity would lead to a clear increase in the spawning stock biomass and an increase in landings of S. solea in the medium-term. The rapido trawl activity could be managed by using a different logic, bearing in mind that catches and incomes would increase with small changes in the spatial pattern of the fishing effort. The present study highlights the importance of taking into account spatial dimensions of fishing fleets and the possible interactions that can occur between fleets and target

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.

Froude Number is the Single Most Important Hydraulic Parameter for Salmonid Spawning Habitat.

Science.gov (United States)

Gillies, E.; Moir, H. J.

2015-12-01

Many gravel-bed rivers exhibit historic straightening or embanking, reducing river complexity and the available habitat for key species such as salmon. A defensible method for predicting salmonid spawning habitat is an important tool for anyone engaged in assessing a river restoration. Most empirical methods to predict spawning habitat use lookup tables of depth, velocity and substrate. However, natural site selection is different: salmon must pick a location where they can successfully build a redd, and where eggs have a sufficient survival rate. Also, using dimensional variables, such as depth and velocity, is problematic: spawning occurs in rivers of differing size, depth and velocity range. Non-dimensional variables have proven useful in other branches of fluid dynamics, and instream habitat is no different. Empirical river data has a high correlation between observed salmon redds and Froude number, without insight into why. Here we present a physics based model of spawning and bedform evolution, which shows that Froude number is indeed a rational choice for characterizing the bedform, substrate, and flow necessary for spawning. It is familiar for Froude to characterize surface waves, but Froude also characterizes longitudinal bedform in a mobile bed river. We postulate that these bedforms and their hydraulics perform two roles in salmonid spawning: allowing transport of clasts during redd building, and oxygenating eggs. We present an example of this Froude number and substrate based habitat characterization on a Scottish river for which we have detailed topography at several stages during river restoration and subsequent evolution of natural processes. We show changes to the channel Froude regime as a result of natural process and validate habitat predictions against redds observed during 2014 and 2015 spawning seasons, also relating this data to the Froude regime in other, nearby, rivers. We discuss the use of the Froude spectrum in providing an indicator of

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...

The size selectivity of the main body of a sampling pelagic pair trawl in freshwater reservoirs during the night

Czech Academy of Sciences Publication Activity Database

Říha, Milan; Jůza, Tomáš; Prchalová, Marie; Mrkvička, Tomáš; Čech, Martin; Draštík, Vladislav; Muška, Milan; Kratochvíl, Michal; Peterka, Jiří; Tušer, Michal; Vašek, Mojmír; Kubečka, Jan

2012-01-01

Roč. 127, September (2012), s. 56-60 ISSN 0165-7836 R&D Projects: GA MZe(CZ) QH81046 Institutional support: RVO:60077344 Keywords : quantitative sampling * gear selectivity * trawl * reservoirs Subject RIV: GL - Fishing Impact factor: 1.695, year: 2012

Changes in habitat availability for outmigrating juvenile salmon (Oncorhychus spp.) following estuary restoration

Science.gov (United States)

Ellings, Christopher S.; Davis, Melanie; Grossman, Eric E.; Hodgson, Sayre; Turner, Kelley L.; Woo PR, Isa; Nakai, Glynnis; Takekawa, Jean E.; Takekawa, John Y.

2016-01-01

The restoration of the Nisqually River Delta (Washington, U.S.A.) represents one of the largest efforts toward reestablishing the ecosystem function and resilience of modified habitat in the Puget Sound, particularly for anadromous salmonid species. The opportunity for outmigrating salmon to access and benefit from the expansion of available tidal habitat can be quantified by several physical attributes, which are related to the ecological and physiological responses of juvenile salmon. We monitored a variety of physical parameters to measure changes in opportunity potential from historic, pre-restoration, and post-restoration habitat conditions at several sites across the delta. These parameters included channel morphology, water quality, tidal elevation, and landscape connectivity. We conducted fish catch surveys across the delta to determine if salmon was utilizing restored estuary habitat. Overall major channel area increased 42% and major channel length increased 131% from pre- to post-restoration conditions. Furthermore, the results of our tidal inundation model indicated that major channels were accessible up to 75% of the time, as opposed to 30% pre-restoration. Outmigrating salmon utilized this newly accessible habitat as quickly as 1 year post-restoration. The presence of salmon in restored tidal channels confirmed rapid post-restoration increases in opportunity potential on the delta despite habitat quality differences between restored and reference sites.

Coastal coho salmon research in the West Fork Smith River: Patterns of coho salmon size and survival within a complex watershed

Science.gov (United States)

Effective habitat restoration planning requires the ability to anticipate fish population responses to altered habitats. The EPA has conducted network-scale research to document habitat-specific growth and survival of juvenile salmonids in a complex watershed. These findings ha...

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.

Measurements and Counts for Larval and Juvenile Beryx Specimens

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Larval alfonsin (Beryx species) were collected in the vicinity of the Southeast Hancock Seamount. A three-net Tucker trawl (I m2 effective mouth opening and 0.333 mm...

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...

Recovery by the Norway lobster Nephrops norvegicus (L.) from the physiological stresses of trawling: Influence of season and live-storage position

DEFF Research Database (Denmark)

Lund, H. S.; Wang, T.; Chang, E. S.

2009-01-01

Live Norway lobsters (Nephrops norvegicus L.) were trawled at depths of 30 to 55 m off the coast of Jutland (Denmark) in late winter (March) and in summer (August) in 2006. Water temperatures at the bottom and surface of the sea were 7 °C and 2 °C during the winter, and 12 °C and 21 °C in the sum......Live Norway lobsters (Nephrops norvegicus L.) were trawled at depths of 30 to 55 m off the coast of Jutland (Denmark) in late winter (March) and in summer (August) in 2006. Water temperatures at the bottom and surface of the sea were 7 °C and 2 °C during the winter, and 12 °C and 21 °C...... in the summer, respectively. The recovery of specific physiological and metabolic variables from the intense stresses associated with capture (trawling and air-exposure during sorting) was followed in seawater at 5 °C in winter or 18 °C in summer. Recovery was compared in lobsters held individually in two......-base status. In winter, a potential metabolic lactic acidosis was compensated by a marked respiratory alkalosis, with significantly increased haemolymph pH and decreased CO2 total content and partial pressure. These effects disappeared gradually over 96 h. Summer lobsters showed combined metabolic...

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...

Use of high-frequency imaging sonar (DIDSON) to observe fish behaviour towards a surface trawl

Czech Academy of Sciences Publication Activity Database

Rakowitz, G.; Tušer, Michal; Říha, Milan; Jůza, Tomáš; Balk, H.; Kubečka, Jan

2012-01-01

Roč. 123, July (2012), s. 37-48 ISSN 0165-7836. [Fish Sampling with Active Methods. České Budějovice, 08.09.2010-11.09.2010] R&D Projects: GA ČR(CZ) GA206/07/1392 Grant - others:NFM(CZ) CZ 0091 Institutional support: RVO:60077344 Keywords : active sampling gear * trawl * fish avoidance behaviour * DIDSON * freshwater reservoir Subject RIV: EH - Ecology, Behaviour Impact factor: 1.695, year: 2012

Baseline study of the distribution of marine debris on soft-bottom habitats associated with trawling grounds in the northern Mediterranean

Directory of Open Access Journals (Sweden)

Pilar Sánchez

2013-06-01

Full Text Available The present study aims to analyse the local and regional variability in the density and typology of marine debris on fishing grounds on the northern Mediterranean continental shelf, and to test relationships between marine litter and trawl fishing activity. Moreover, the colonization of plastics was examined in order to study the importance of plastics as a source of impact on marine communities and their further environmental implications. This study surveyed 11 sites, associated with trawling grounds and subjected to different levels of fishing intensity, located in four areas of the Mediterranean: one in Italy, the Central Tyrrhenian coast, one in Greece, the eastern Ionian coast, and two in Spain, the Murcian and Catalan coasts. Samples were collected during an oceanographic cruise undertaken from the 21 May to the 24 June 2009. Results showed geographical variation in the density of marine debris which ranged from 0 to 405 pieces per hectare in the surveyed areas, plastics being the dominant components. Variability within sites was higher than between areas, indicating small-scale patchiness in the distribution of the debris over the seafloor. Though the study areas were within trawling grounds, the density of debris was not significantly correlated with fishing effort. More than 30% of plastics were between 10 and 20 cm width/length, and more than 40% of the plastics were colonized by a biofilm of microorganisms, suggesting indirect effects on benthic communities.

The mobilisation of sediment by demersal otter trawls.

Science.gov (United States)

O'Neill, F G; Summerbell, K

2011-05-01

The mobilisation of sediment by towed demersal fishing gears has been related to the release of nutrients, benthic infaunal mortality and the resuspension of phytoplankton cysts and copepod eggs. Hence, to understand the broader environmental and ecological implications of demersal fishing, it is important to be able to estimate accurately the amount of sediment put into the water column by towed gears. Experimental trials were carried out in the Moray Firth, Scotland, to measure the quantity of sediment remobilised by trawl gear components. It is demonstrated, for a given sediment type, that there is a relationship between the hydrodynamic drag of the gear element and the mass of sediment entrained behind it. A better understanding of this relationship and the hydrodynamic processes involved will lead to the development of accurate predictive models and aid the design of fishing gears of reduced impact. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Kelp and Eelgrass in Puget Sound

National Research Council Canada - National Science Library

Mumford, Jr, Thomas F

2007-01-01

.... Shellfish, such as crabs and bivalves, use eelgrass beds for habitat and nursery areas. Fishes such as juvenile salmonids use eelgrass beds as migratory corridors as they pass through Puget Sound; the beds provide both protection from predators and abundant food.

Juvenile Idiopathic Arthritis

Directory of Open Access Journals (Sweden)

Kenan Barut

2017-04-01

Full Text Available Juvenile idiopathic arthritis is the most common chronic rheumatic disease of unknown aetiology in childhood and predominantly presents with peripheral arthritis. The disease is divided into several subgroups, according to demographic characteristics, clinical features, treatment modalities and disease prognosis. Systemic juvenile idiopathic arthritis, which is one of the most frequent disease subtypes, is characterized by recurrent fever and rash. Oligoarticular juvenile idiopathic arthritis, common among young female patients, is usually accompanied by anti-nuclear antibodie positivity and anterior uveitis. Seropositive polyarticular juvenile idiopathic arthritis, an analogue of adult rheumatoid arthritis, is seen in less than 10% of paediatric patients. Seronegative polyarticular juvenile idiopathic arthritis, an entity more specific for childhood, appears with widespread large- and small-joint involvement. Enthesitis-related arthritis is a separate disease subtype, characterized by enthesitis and asymmetric lower-extremity arthritis. This disease subtype represents the childhood form of adult spondyloarthropathies, with human leukocyte antigen-B27 positivity and uveitis but commonly without axial skeleton involvement. Juvenile psoriatic arthritis is characterized by a psoriatic rash, accompanied by arthritis, nail pitting and dactylitis. Disease complications can vary from growth retardation and osteoporosis secondary to treatment and disease activity, to life-threatening macrophage activation syndrome with multi-organ insufficiency. With the advent of new therapeutics over the past 15 years, there has been a marked improvement in juvenile idiopathic arthritis treatment and long-term outcome, without any sequelae. The treatment of juvenile idiopathic arthritis patients involves teamwork, including an experienced paediatric rheumatologist, an ophthalmologist, an orthopaedist, a paediatric psychiatrist and a physiotherapist. The primary goals

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...

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...

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...

Evaluation of an ion adsorption method to estimate intragravel flow velocity in salmonid spawning gravels

Science.gov (United States)

James L. Clayton; John G. King; Russell F. Thurow

1996-01-01

Intragravel water exchange provides oxygenated water, removes metabolic waste, and is an essential factor in salmonid embryo survival. Measurements of intragravel flow velocity have been suggested as an index of gravel quality and also as a useful predictor of fry emergence; however, proposed methods for measuring velocity in gravel are problematic. We evaluate an ion...

Temporal modification in cardiac rhythmicity of Nephrops norvegicus (Crustacea: Decapoda in relation to trawl capture stress

Directory of Open Access Journals (Sweden)

Jacopo Aguzzi

2005-09-01

Full Text Available The effects of trawling on cardiac rhythmicity of Nephrops norvegicus (L. are still mostly unknown. Ultradian rhythms reported in previous studies may result from trawling capture stress, thus disappearing following acclimatisation to laboratory conditions. To test this hypothesis, 34 time series of cardiac activity data recorded in constant darkness were studied by Fourier analysis. Spectral decomposition of time series was obtained by defining the fundamental or circadian harmonic (CH in 24-h together with 9 submultiples of this period. The power content (PC of each harmonic was estimated in data segments of 24-h duration (days, giving graphic matrices of PC values over consecutive days. Values of PC for 9 submultiples were summed and studied in a block named ultradian band (UB. The modification in the PC of the CH and of the UB was evaluated during laboratory acclimatisation. A significant increase in the PC of the circadian harmonic component (CH over consecutive days of testing was observed. These findings suggest that, rather than being a product of dim light environmental fluctuations experienced by the animals from the deep waters of the continental slope, ultradian periodicity could well be caused by the stress of capture.

Environmental eff ects on the availability of shallow and deep-water hake to the demersaltrawl survey in Namibian waters

DEFF Research Database (Denmark)

Kainge, Paulus Inekela

at different size groups (juvenile, small, medium and large) of the two hake species. Most of the years, the environmental data were collected independent of the fishing operations usually on few selected transects with limited spatial overlap between the CTD and the trawl stations. The results, however...

Effects of environmental variables on survey catch rates and distribution by size of shallow- and deep-water Cape hakes, Merluccius capensis and Merluccius paradoxus off Namibia

DEFF Research Database (Denmark)

Kainge, Paulus Inekela; van der Plas, A. K.; Bartholomae, C. H.

2017-01-01

In order to study the effects of temperature, oxygen, salinity and time of day on survey trawl catches, we modeled observed catches of juvenile, small, medium and large hakes per station as functions of zenith angle of the sun, geographical position, year, temperature, salinity, oxygen and depth....

Trawling disturbance on benthic ecosystems and consequences on commercial species: a northwestern Mediterranean case study

Directory of Open Access Journals (Sweden)

Alba Muntadas

2014-03-01

Full Text Available Trawling is known to disturb benthic communities and habitats, which may in turn indirectly affect populations of commercial species that live in close association with the seabed. The degree of impact on both benthic communities and demersal species depends on the fishing effort level. This may vary over the year because of the fleet dynamics, which are in turn normally driven by the main target species’ life cycle. In this study we describe changes in benthic functional components of a northwestern Mediterranean fishing ground that represents a recruitment area for an important target species (red mullet, Mullus barbatus. This fishing ground experiences a varying intensity of fishing effort over the year and benthic functional components under different levels of trawling were compared with an unfished, control area. Traits related to sexual maturity and life span for infauna and body size and life span for epifauna were found to vary with fishing activity. Potential effects of these changes on ecological functioning and the impact on red mullet population are discussed. The development of fisheries management plans under an ecosystem based fisheries management (EBFM requires the links between target species and benthic communities’ disturbance due to fishing practices to be explicitly considered.

Testing Nordmøre grids on the target and by-catch species of the commercial bottom trawl fishery in the Gulf of Cadiz

Directory of Open Access Journals (Sweden)

Mariángeles Gamaza

2015-12-01

Full Text Available Sorting grids have been tested worldwide in trawl fisheries. Here we report upon the first trials performed using Nordmøre sorting grids with four different bar spacings in the trawl fisheries of the Gulf of Cadiz targeting crustaceans as the main resource. A total of 288 valid hauls and 67 commercial species were caught. Escapement and escape size selectivity were evaluated for the most important target and by-catch species. A decrease in the percentage of biomass escape was recorded with increasing grid spacing for the two target species, deep-water rose shrimp (Parapenaeus longirostris and Norway lobster (Nephrops norvegicus, from 24% to 8% for the former and from 86 to 9% for the latter, with a 15-mm and 30-mm grid respectively. In general, high escape rates were found for most finfish and cephalopods. For hake (Merluccius merluccius, as the main by-catch species, the results showed an escape rate decreasing from 96% to 71% as the bar spacing increased. Our findings suggest the 30-mm grid would be effective for the deep-water crustacean trawlers but different mitigation measures will be required for other métiers in the multispecies trawl fishery of the Gulf of Cadiz.

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.

Assessment of Salmonids and their Habitat Conditions in the Walla Walla River Basin of Washington : 2000 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Mendel, Glen Wesley; Karl, David; Coyle, Terrence

2001-11-01

Concerns about the decline of native salmon and trout populations have increased among natural resource managers and the public in recent years. As a result, a multitude of initiatives have been implemented at the local, state, and federal government levels. These initiatives include management plans and actions intended to protect and restore salmonid fishes and their habitats. In 1998 bull trout were listed under the Endangered Species Act (ESA), as ''Threatened'', for the Walla Walla River and its tributaries. Steelhead were listed as ''Threatened'' in 1999 for the mid-Columbia River and its tributaries. These ESA listings emphasize the need for information about the threatened salmonid populations and their habitats. The Washington Department of Fish and Wildlife (WDFW) is entrusted with ''the preservation, protection, and perpetuation of fish and wildlife....[and to] maximize public recreational or commercial opportunities without impairing the supply of fish and wildlife (WAC 77. 12.010).'' In consideration of this mandate, the WDFW submitted a proposal in December 1997 to the Bonneville Power Administration (BPA) for a study to assess salmonid distribution, relative abundance, genetics, and the condition of their habitats in the Walla Walla River basin. The primary purposes of this project are to collect baseline biological and habitat data, to identify major data gaps, and to draw conclusions whenever possible. The study reported herein details the findings of the 2000 field season (March to November, 2000).

Development of a System-Wide Predator Control Program: Stepwise Implementation of a Predation Index, Predator Control Fisheries, and Evaluation Plan in the Columbia River Basin; Northern Pikeminnow Management Program, 2002 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Porter, Russell G.; Winther, Eric C.; Fox, Lyle G.

2004-01-01

This report presents results for year twelve in a basin-wide program to harvest northern pikeminnow1 (Ptychocheilus oregonensis). This program was started in an effort to reduce predation by northern pikeminnow on juvenile salmonids during their emigration from natal streams to the ocean. Earlier work in the Columbia River Basin suggested predation by northern pikeminnow on juvenile salmonids might account for most of the 10-20% mortality juvenile salmonids experience in each of eight Columbia River and Snake River reservoirs. Modeling simulations based on work in John Day Reservoir from 1982 through 1988 indicated that, if predator-size northern pikeminnow were exploited at a 10-20% rate, the resulting restructuring of their population could reduce their predation on juvenile salmonids by 50%. To test this hypothesis, we implemented a sport-reward angling fishery and a commercial longline fishery in the John Day Pool in 1990. We also conducted an angling fishery in areas inaccessible to the public at four dams on the mainstem Columbia River and at Ice Harbor Dam on the Snake River. Based on the success of these limited efforts, we implemented three test fisheries on a system-wide scale in 1991--a tribal longline fishery above Bonneville Dam, a sport-reward fishery, and a dam-angling fishery. Low catch of target fish and high cost of implementation resulted in discontinuation of the tribal longline fishery. However, the sport-reward and dam-angling fisheries were continued in 1992 and 1993. In 1992, we investigated the feasibility of implementing a commercial longline fishery in the Columbia River below Bonneville Dam and found that implementation of this fishery was also infeasible. Estimates of combined annual exploitation rates resulting from the sport-reward and damangling fisheries remained at the low end of our target range of 10-20%. This suggested the need for additional effective harvest techniques. During 1991 and 1992, we developed and tested a modified

Estimation of alewife biomass in Lake Michigan, 1967-1978

Science.gov (United States)

Hatch, Richard W.; Haack, Paul M.; Brown, Edward H.

1981-01-01

The buildup of salmonid populations in Lake Michigan through annual stockings of hatchery-reared fish may become limited by the quantity of forage fish, mainly alewives Alosa pseudoharengus, available for food. As a part of a continuing examination of salmonid predator-prey relations in Lake Michigan, we traced changes in alewife biomass estimated from bottom-trawl surveys conducted in late October and early November 1967–1978. Weight of adult alewives trawled per 0.5 hectare of bottom (10-minute drag) at 16 depths along eight transects between 1973 and 1977 formed a skewed distribution: 72 of 464 drags caught no alewives; 89 drags caught less than 1 kg; and 2 drags caught more than 100 kg (maximum 159 kg). Analysis of variance in normalized catch per tow indicated highly significant differences between the main effects of years and depths, and highly significant differences in the interactions of years and transects, years and depths, and transects and depths. Five geographic and depth strata, formed by combining parts of transects wherein mean catch rate did not differ significantly, were the basis for calculating annual estimates of adult alewife biomass (with 90% confidence intervals). Estimated biomass of alewives (±90% confidence limits) in Lake Michigan proper (Green Bay and Grand Traverse Bay excluded) rose gradually from 46,000 (±9,000) t in 1967 to 114,000 (±17,000) t in 1973, declined to 45,000 (±8,000) t in 1977, and rose to 77,000 (±19,000) t in 1978.

Can biosecurity and local network properties predict pathogen species richness in the salmonid industry?

Science.gov (United States)

More, Simon J.; Geoghegan, Fiona; McManus, Catherine; Hill, Ashley E.; Martínez-López, Beatriz

2018-01-01

Salmonid farming in Ireland is mostly organic, which implies limited disease treatment options. This highlights the importance of biosecurity for preventing the introduction and spread of infectious agents. Similarly, the effect of local network properties on infection spread processes has rarely been evaluated. In this paper, we characterized the biosecurity of salmonid farms in Ireland using a survey, and then developed a score for benchmarking the disease risk of salmonid farms. The usefulness and validity of this score, together with farm indegree (dichotomized as ≤ 1 or > 1), were assessed through generalized Poisson regression models, in which the modeled outcome was pathogen richness, defined here as the number of different diseases affecting a farm during a year. Seawater salmon (SW salmon) farms had the highest biosecurity scores with a median (interquartile range) of 82.3 (5.4), followed by freshwater salmon (FW salmon) with 75.2 (8.2), and freshwater trout (FW trout) farms with 74.8 (4.5). For FW salmon and trout farms, the top ranked model (in terms of leave-one-out information criteria, looic) was the null model (looic = 46.1). For SW salmon farms, the best ranking model was the full model with both predictors and their interaction (looic = 33.3). Farms with a higher biosecurity score were associated with lower pathogen richness, and farms with indegree > 1 (i.e. more than one fish supplier) were associated with increased pathogen richness. The effect of the interaction between these variables was also important, showing an antagonistic effect. This would indicate that biosecurity effectiveness is achieved through a broader perspective on the subject, which includes a minimization in the number of suppliers and hence in the possibilities for infection to enter a farm. The work presented here could be used to elaborate indicators of a farm’s disease risk based on its biosecurity score and indegree, to inform risk-based disease surveillance and

Can biosecurity and local network properties predict pathogen species richness in the salmonid industry?

Directory of Open Access Journals (Sweden)

Tadaishi Yatabe

Full Text Available Salmonid farming in Ireland is mostly organic, which implies limited disease treatment options. This highlights the importance of biosecurity for preventing the introduction and spread of infectious agents. Similarly, the effect of local network properties on infection spread processes has rarely been evaluated. In this paper, we characterized the biosecurity of salmonid farms in Ireland using a survey, and then developed a score for benchmarking the disease risk of salmonid farms. The usefulness and validity of this score, together with farm indegree (dichotomized as ≤ 1 or > 1, were assessed through generalized Poisson regression models, in which the modeled outcome was pathogen richness, defined here as the number of different diseases affecting a farm during a year. Seawater salmon (SW salmon farms had the highest biosecurity scores with a median (interquartile range of 82.3 (5.4, followed by freshwater salmon (FW salmon with 75.2 (8.2, and freshwater trout (FW trout farms with 74.8 (4.5. For FW salmon and trout farms, the top ranked model (in terms of leave-one-out information criteria, looic was the null model (looic = 46.1. For SW salmon farms, the best ranking model was the full model with both predictors and their interaction (looic = 33.3. Farms with a higher biosecurity score were associated with lower pathogen richness, and farms with indegree > 1 (i.e. more than one fish supplier were associated with increased pathogen richness. The effect of the interaction between these variables was also important, showing an antagonistic effect. This would indicate that biosecurity effectiveness is achieved through a broader perspective on the subject, which includes a minimization in the number of suppliers and hence in the possibilities for infection to enter a farm. The work presented here could be used to elaborate indicators of a farm's disease risk based on its biosecurity score and indegree, to inform risk-based disease surveillance and

Prioritizing fishery management for loggerhead turtle (Caretta caretta) conservation in the northern Adriatic Sea from reproductive value analysis

OpenAIRE

Lazar, Bojan; Heppell, Selina S.

2013-01-01

Fisheries bycatch often affects particular size classes of turtles. Because of the late age at maturity, the reproductive value (RV) of small juvenile, large juvenile and adult loggerheads vary by orders of magnitude. RV provides a relative measure of value for individuals, thereby allowing us to estimate the effects of different stressors based on the number of animals killed. Using RV as a comparative index, we assessed the relative impact of trawl and gillnet fi sheries operating in the no...

Virucidal activity of two Iodophors to salmonid viruses

Science.gov (United States)

Amend, Donald F.; Pietsch, John P.

1972-01-01

Wescodyne® and Betadine®, organic iodine complexes, were compared in vitro for virucidal activity against infectious hematopoietic necrosis (IHN), infectious pancreatic necrosis (IPN), and viral hemorrhagic septicemia (VHS) viruses. Both iodophors were about equally effective on all three viruses. Each iodophor completely destroyed IHN virus within 30 sec at 12 ppm iodine, and was not affected by water hardness. Virucidal activity, however, was reduced at pH levels above 8.0 and in the presence of organic matter. Wescodyne was also compared with seven disinfectants commonly used in fish hatcheries, for virucidal properties against IHN virus. Wescodyne and chlorine were the only disinfectants to completely destroy the virus. Either Wescodyne or Betadine would effectively destroy the salmonid viruses at less than 25 ppm iodine within 5 min in solutions near neutrality.

Monitoring of downstream salmon and steelhead at federal hydroelectric facilities -- 1995. Annual report 1995

International Nuclear Information System (INIS)

Martinson, R.D.; Graves, R.J.; Langeslay, M.J.; Killins, S.D.

1996-12-01

The seaward migration of juvenile salmonids was monitored by the National Marine Fisheries Service (NMFS) at Bonneville and John Day Dams on the Columbia river in 1995. The NMFS Smolt Monitoring Project is part of a larger Smolt Monitoring Program (SMP) coordinated by the Fish Passage Center (FPC) for the Columbia Basin Fish and Wildlife Authority. This program focuses on protecting, mitigating, and enhancing fish populations affected by the development and operation of hydroelectric power plants on the Columbia River. The purpose of the SMP is to monitor the migration of the juvenile salmonid stocks in the Columbia basin and make flow and spill recommendations designed to facilitate fish passage. Data are also used for travel time, migration timing, and relative run size analysis. The purpose of the NMFS portion of the program is to provide FPC with species and project specific real time data from John Day and Bonneville Dams

Juvenile angiofibromer

DEFF Research Database (Denmark)

Thuesen, Anne Daugaard; Jakobsen, John; Nepper-Rasmussen, Jørgen

2005-01-01

Juvenile angiofibroma is a rare, benign, rich vascular tumor, and approximately one new case is diagnosed in Denmark each year. It sits in the foramen sphenopalatinum and occurs in boys from 14 to 25 years of age. The most frequent initial symptoms are nasal obstruction and epistaxis. Through...... the years, the treatment of juvenile angiofibroma has included many methods, including surgical excision, electrocoagulation, interstitial or external radiation therapy, cryosurgery, hormone administration and chemotherapy. Radiation, chemotherapy and surgery have proven to be the most effective treatments...

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...

Impact of beaver dams on abundance and distribution of anadromous salmonids in two lowland streams in Lithuania.

Science.gov (United States)

Virbickas, Tomas; Stakėnas, Saulius; Steponėnas, Andrius

2015-01-01

European beaver dams impeded movements of anadromous salmonids as it was established by fishing survey, fish tagging and redd counts in two lowland streams in Lithuania. Significant differences in abundancies of other litophilic fish species and evenness of representation by species in the community were detected upstream and downstream of the beaver dams. Sea trout parr marked with RFID tags passed through several successive beaver dams in upstream direction, but no tagged fish were detected above the uppermost dam. Increase in abundances of salmonid parr in the stream between the beaver dams and decrease below the dams were recorded in November, at the time of spawning of Atlantic salmon and sea trout, but no significant changes were detected in the sections upstream of the dams. After construction of several additional beaver dams in the downstream sections of the studied streams, abundance of Atlantic salmon parr downstream of the dams decreased considerably in comparison with that estimated before construction.

Impact of beaver dams on abundance and distribution of anadromous salmonids in two lowland streams in Lithuania.

Directory of Open Access Journals (Sweden)

Tomas Virbickas

Full Text Available European beaver dams impeded movements of anadromous salmonids as it was established by fishing survey, fish tagging and redd counts in two lowland streams in Lithuania. Significant differences in abundancies of other litophilic fish species and evenness of representation by species in the community were detected upstream and downstream of the beaver dams. Sea trout parr marked with RFID tags passed through several successive beaver dams in upstream direction, but no tagged fish were detected above the uppermost dam. Increase in abundances of salmonid parr in the stream between the beaver dams and decrease below the dams were recorded in November, at the time of spawning of Atlantic salmon and sea trout, but no significant changes were detected in the sections upstream of the dams. After construction of several additional beaver dams in the downstream sections of the studied streams, abundance of Atlantic salmon parr downstream of the dams decreased considerably in comparison with that estimated before construction.

Parenting and juvenile delinquency

NARCIS (Netherlands)

Hoeve, M.

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 use of at‐sea‐sampling data to dissociate environmental variability in Norway lobster (Nephrops norvegicus) catches to improve resource exploitation efficiency within the Skagerrak/Kattegat trawl fishery

DEFF Research Database (Denmark)

Feekings, Jordan P.; Christensen, Asbjørn; Jonsson, Patrik

2015-01-01

Research into the influence of environmental variables on the behaviour of Norway lobster (Nephrops norvegicus), and hence catch rates, dates back to the 1960s (e.g., Höglund and Dybern, Diurnal and seasonal variations in the catch‐composition of Nephrops norvegicus (L.) at the Swedish west coast...... on commercial trawl catches of Nephrops norvegicus (L.). ICES J. Mar. Sci. 58:1318). Here, we aimed to dissociate environmental variability in Norway lobster catches to improve resource exploitation efficiency within the Skagerrak and Kattegat trawl fisheries by utilising data collected as part of an extensive...

Juvenile delinquency and correctional treatment in Britain

OpenAIRE

堀尾, 良弘; ホリオ, ヨシヒロ; Yoshihiro, Horio

2006-01-01

Japanese modernistic culture is influenced not a little from Britain. In looking at the Juvenile Law and the history of correctional treatment in Britain, understanding of today's juvenile delinquency and treatment deepen. Moreover, the background and issue of juvenile delinquency in Britain are also discussed. As a feature of the juvenile delinquency in Britain, the common field with Japan and the field peculiar to Britain became clear in each. It is common to the world that the juvenile del...

Non-native salmonids affect amphibian occupancy at multiple spatial scales

Science.gov (United States)

Pilliod, David S.; Hossack, Blake R.; Bahls, Peter F.; Bull, Evelyn L.; Corn, Paul Stephen; Hokit, Grant; Maxell, Bryce A.; Munger, James C.; Wyrick, Aimee

2010-01-01

Aim The introduction of non-native species into aquatic environments has been linked with local extinctions and altered distributions of native species. We investigated the effect of non-native salmonids on the occupancy of two native amphibians, the long-toed salamander (Ambystoma macrodactylum) and Columbia spotted frog (Rana luteiventris), across three spatial scales: water bodies, small catchments and large catchments. Location Mountain lakes at ≥ 1500 m elevation were surveyed across the northern Rocky Mountains, USA. Methods We surveyed 2267 water bodies for amphibian occupancy (based on evidence of reproduction) and fish presence between 1986 and 2002 and modelled the probability of amphibian occupancy at each spatial scale in relation to habitat availability and quality and fish presence. Results After accounting for habitat features, we estimated that A. macrodactylum was 2.3 times more likely to breed in fishless water bodies than in water bodies with fish. Ambystoma macrodactylum also was more likely to occupy small catchments where none of the water bodies contained fish than in catchments where at least one water body contained fish. However, the probability of salamander occupancy in small catchments was also influenced by habitat availability (i.e. the number of water bodies within a catchment) and suitability of remaining fishless water bodies. We found no relationship between fish presence and salamander occupancy at the large-catchment scale, probably because of increased habitat availability. In contrast to A. macrodactylum, we found no relationship between fish presence and R. luteiventris occupancy at any scale. Main conclusions Our results suggest that the negative effects of non-native salmonids can extend beyond the boundaries of individual water bodies and increase A. macrodactylum extinction risk at landscape scales. We suspect that niche overlap between non-native fish and A. macrodactylum at higher elevations in the northern Rocky

Cumulative effects of logging road sediment on salmonid populations in the Clearwater River, Jefferson County, Washington

Science.gov (United States)

C. J. Cederholm; L. M. Reid; E. O. Salo

1981-01-01

Abstract - The nature of sediment production from logging roads and the effect of the resulting sediment on salmonid spawning success in the Clearwater River drainage have been studied for eight years. The study includes intensive and extensive analyses of field situations, supplemented by several controlled experiments. It was found that significant amounts (15-25...

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.

Analyses of Trawling Track and Fishing Activity Based on the Data of Vessel Monitoring System (VMS)：A Case Study of the Single Otter Trawl Vessels in the Zhoushan Fishing Ground

Institute of Scientific and Technical Information of China (English)

WANG Yang; WANG Yingbin; ZHENG Ji

2015-01-01

The original purpose of Vessel Monitoring System (VMS) is for enforcement and control of vessel sailing. With the ap-plication of VMS in fishing vessels, more and more population dynamic studies have used VMS data to improve the accuracy of fisheries stock assessment. In this paper, we simulated the trawl trajectory under different time intervals using the cubic Hermite spline (cHs) interpolation method based on the VMS data of 8 single otter trawl vessels (totally 36000 data items) fishing in Zhou-shan fishing ground from September 2012 to December 2012, and selected the appropriate time interval. We then determined vessels’ activities (fishing or non-fishing) by comparing VMS speed data with the corresponding speeds from logbooks. The results showed that the error of simulated trajectory greatly increased with the increase of time intervals of VMS data when they were longer than 30 minutes. Comparing the speeds from VMS with those from the corresponding logbooks, we found that the vessels’ speeds were be-tween 2.5kn and 5.0kn in fishing. The cHs interpolation method is a new choice for improving the accuracy of estimation of sailing trajectory, and the VMS can be used to determine the vessels’ activities with the analysis of their trajectories and speeds. Therefore, when the fishery information is limited, VMS can be one of the important data sources for fisheries stock assessment, and more at-tention should be paid to its construction and application to fisheries stock assessment and management.

SEM/EDS and optical microscopy analyses of microplastics in ocean trawl and fish guts.

Science.gov (United States)

Wang, Zhong-Min; Wagner, Jeff; Ghosal, Sutapa; Bedi, Gagandeep; Wall, Stephen

2017-12-15

Microplastic particles from Atlantic and Pacific Ocean trawls, lab-fed fish guts and ocean fish guts have been characterized using optical microscopy and SEM/EDS in terms of size, morphology, and chemistry. We assessed whether these measurements could serve as a rapid screening process for subsequent identification of the likely microplastic candidates by micro-spectroscopy. Optical microscopy enabled morphological classification of the types of particles or fibers present in the sample, as well as the quantification of particle size ranges and fiber lengths. SEM/EDS analysis was used to rule out non-plastic particles and screen the prepared samples for potential microplastic, based on their element signatures and surface characteristics. Chlorinated plastics such as polyvinyl chloride (PVC) could be easily identified with SEM/EDS due to their unique elemental signatures including chlorine, as could mineral species that are falsely identified as plastics by optical microscopy. Particle morphology determined by optical microscopy and SEM suggests the fish ingested particles contained both degradation fragments from larger plastic pieces and also manufactured microplastics. SEM images of microplastic particle surfaces revealed characteristic cracks consistent with environmental exposure, as well as pigment particles consistent with manufactured materials. Most of the microplastic surfaces in the fish guts and ocean trawls were covered with biofilms, radiolarians, and crustaceans. Many of the fish stomachs contained micro-shell pieces which visually resembled microplastics. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of tow duration on catch performance of trawl survey in the Mediterranean Sea.

Directory of Open Access Journals (Sweden)

Antonello Sala

Full Text Available The aim of this study was to assess the effect of tow duration on catch per unit of swept area (CPUE, trawl catch performance, and the proportion of the species caught in a trawl survey. Longer tows are expected to have a greater probability of catching species. An average of 26 species were caught in the first 30 minutes, whereas only about one additional species was caught in the next 30 minutes in longer tows. The shorter tows involved a decrement in catch weight for 11 of the 12 target species sampled, demonstrating that tow duration did affect catch per unit of swept area CPUE. The shorter tows were associated with a significant reduction of the overall CPUE in terms of weight of the main target species and of the total catch (circa 60%. The same strong reduction of around 70% was found in particular for European hake (Merluccius merluccius and surmullet (Mullus spp and 50% for Nephrops (Nephrops norvegicus. The shorter tows were less efficient in catching large-sized hake, surmullet, Nephrops, Atlantic horse mackerel (Trachurus trachurus, and poor cod (Trisopterus minutus, even though the difference was significant only for Nephrops. Regardless of the p-value statistic, these findings suggest that the continuity of survey time series would be severely impaired by changing tow duration. Further work is required to explore a way to reduce tow duration without reducing CPUE.

Assessment of salmonids and their habitat conditions in the Walla Walla River Basin of Washington : 2000 annual report; ANNUAL

International Nuclear Information System (INIS)

Mendel, Glen Wesley; Karl, David; Coyle, Terrence

2001-01-01

Concerns about the decline of native salmon and trout populations have increased among natural resource managers and the public in recent years. As a result, a multitude of initiatives have been implemented at the local, state, and federal government levels. These initiatives include management plans and actions intended to protect and restore salmonid fishes and their habitats. In 1998 bull trout were listed under the Endangered Species Act (ESA), as ''Threatened'', for the Walla Walla River and its tributaries. Steelhead were listed as ''Threatened'' in 1999 for the mid-Columbia River and its tributaries. These ESA listings emphasize the need for information about the threatened salmonid populations and their habitats. The Washington Department of Fish and Wildlife (WDFW) is entrusted with ''the preservation, protection, and perpetuation of fish and wildlife....[and to] maximize public recreational or commercial opportunities without impairing the supply of fish and wildlife (WAC 77.12.010).'' In consideration of this mandate, the WDFW submitted a proposal in December 1997 to the Bonneville Power Administration (BPA) for a study to assess salmonid distribution, relative abundance, genetics, and the condition of their habitats in the Walla Walla River basin. The primary purposes of this project are to collect baseline biological and habitat data, to identify major data gaps, and to draw conclusions whenever possible. The study reported herein details the findings of the 2000 field season (March to November, 2000)

Bilateral, independent juvenile nasopharyngeal angiofibroma

DEFF Research Database (Denmark)

Mørkenborg, Marie-Louise; Frendø, M; Stavngaard, T

2015-01-01

BACKGROUND: Juvenile nasopharyngeal angiofibroma is a benign, vascular tumour that primarily occurs in adolescent males. Despite its benign nature, aggressive growth patterns can cause potential life-threatening complications. Juvenile nasopharyngeal angiofibroma is normally unilateral, originating...... from the sphenopalatine artery, but bilateral symptoms can occur if a large tumour extends to the contralateral side of the nasopharynx. This paper presents the first reported case of true bilateral extensive juvenile nasopharyngeal angiofibroma involving clinically challenging pre-surgical planning...... embolisation. Radical removal performed as one-step, computer-assisted functional endoscopic sinus surgery was performed. The follow-up period was uncomplicated. CONCLUSION: This case illustrates the importance of suspecting bilateral juvenile nasopharyngeal angiofibroma in patients presenting with bilateral...

Criminal Profiles of Violent Juvenile Sex and Violent Juvenile Non-Sex Offenders: An Explorative Longitudinal Study

Science.gov (United States)

van Wijk, Anton Ph.; Mali, Bas R. F.; Bullens, Ruud A. R.; Vermeiren, Robert R.

2007-01-01

Few studies have longitudinally investigated the criminal profiles of violent juvenile sex and violent juvenile non-sex offenders. To make up for this lack, this study used police records of juveniles to determine the nature of the criminal profiles of violent sex offenders (n = 226) and violent non-sex offenders (n = 4,130). All offenders…

Juvenile morphology in baleen whale phylogeny.

Science.gov (United States)

Tsai, Cheng-Hsiu; Fordyce, R Ewan

2014-09-01

Phylogenetic reconstructions are sensitive to the influence of ontogeny on morphology. Here, we use foetal/neonatal specimens of known species of living baleen whales (Cetacea: Mysticeti) to show how juvenile morphology of extant species affects phylogenetic placement of the species. In one clade (sei whale, Balaenopteridae), the juvenile is distant from the usual phylogenetic position of adults, but in the other clade (pygmy right whale, Cetotheriidae), the juvenile is close to the adult. Different heterochronic processes at work in the studied species have different influences on juvenile morphology and on phylogenetic placement. This study helps to understand the relationship between evolutionary processes and phylogenetic patterns in baleen whale evolution and, more in general, between phylogeny and ontogeny; likewise, this study provides a proxy how to interpret the phylogeny when fossils that are immature individuals are included. Juvenile individuals in the peramorphic acceleration clades would produce misleading phylogenies, whereas juvenile individuals in the paedomorphic neoteny clades should still provide reliable phylogenetic signals.

Patterns of variation and covariation in the shapes of mandibular bones of juvenile salmonids in the genus Oncorhynchus

Science.gov (United States)

Watson, Sawyer; Couture, Ryan B.; McKibben, Natasha S.; Nichols, James T.; Richardson, Shannon E.; Noakes, David L. G.

2016-01-01

SUMMARY What is the nature of evolutionary divergence of the jaw skeleton within the genus Oncorhynchus? How can two associated bones evolve new shapes and still maintain functional integration? Here, we introduce and test a ‘concordance’ hypothesis, in which an extraordinary matching of the evolutionary shape changes of the dentary and angular articular serves to preserve their fitting together. To test this hypothesis, we examined morphologies of the dentary and angular articular at parr (juvenile) stage, and at three levels of biological organization – between salmon and trout, between sister species within both salmon and trout, and among three types differing in life histories within one species, O. mykiss. The comparisons show bone shape divergences among the groups at each level; morphological divergence between salmon and trout is marked even at this relatively early life history stage. We observed substantial matching between the two mandibular bones in both pattern and amount of shape variation, and in shape covariation across species. These findings strongly support the concordance hypothesis, and reflect functional and/or developmental constraint on morphological evolution. We present evidence for developmental modularity within both bones. The locations of module boundaries were predicted from the patterns of evolutionary divergences, and for the dentary, at least, would appear to facilitate its functional association with the angular articular. The modularity results suggest that development has biased the course of evolution. PMID:26372063

Larval, pre-juvenile and juvenile development of Diapterus peruvianus (Perciformes: Gerreidae

Directory of Open Access Journals (Sweden)

Sylvia Patricia Adelheid Jiménez Rosenberg

2003-06-01

Full Text Available The development of Diapterus peruvianus (Sauvage 1879 is based on 60 larvae collected in superficial tows made in Bahía Concepción, and on 16 prejuvenile and juvenile organisms collected in Bahía de La Paz, B. C. S., México, using a standard plankton net and a rectangular epibenthonic net, respectively. Larvae of D. peruvianus show three large blotches on the dorsum of the gut that can fuse together and give the appearance of one large continuous blotch. There are two to three pre-anal pigments and 16 post-anal pigments in the ventral midline; cephalic pigments are present from the postflexion stage, as well as a serrated preoperculum. The prejuvenile and juvenile organisms are distinguished by their body depth, the analfin formula, the serrated preoperculum and the base pigments in the dorsal and anal fins.El desarrollo de Diapterus peruvianus se analizó con base en 60 larvas recolectadas en Bahía Concepción y 16 pre-juveniles y juveniles recolectados en la Ensenada de La Paz, B. C. S. México, usando respectivamente, una red estándar de plancton en arrastres superficiales y una red epibentónica para arrastres de plancton. Las larvas presentan desde la pre-flexión tres manchas alargadas sobre la superficie dorsal de la masa visceral, que pueden unirse y dar apariencia de pigmentación continua, observándose hasta 16 pigmentos post-anales en la línea media ventral y de dos a tres pigmentos pre-anales; la pigmentación cefálica así como la forma aserrada del pre-opérculo característica del género, aparecen a partir de la post-flexión. Los organismos pre-juveniles y juveniles se distinguen por la profundidad del cuerpo, la fórmula de la aleta anal, la fina forma aserrada del pre-opérculo y la pigmentación en la base de las aletas dorsal y anal.

From fishing to fish processing: Separation of fish from crustaceans in the Norway lobster-directed multispecies trawl fishery improves seafood quality

DEFF Research Database (Denmark)

Karlsen, Junita Diana; Krag, Ludvig Ahm; Albertsen, Christoffer Moesgaard

2015-01-01

Fishing gears have negative impacts on seafood quality, especially on fish in the mixed trawl fishery targeting Norway lobster (Nephrops norvegicus). In this fishery, which is worth about €80 millions in Denmark alone, the quality of fish can be significantly improved by simple gear changes....... A trawl codend divided into an upper and lower codend was designed to separate fish from Norway lobster during the fishing process by encourage fish to swim into the upper codend by using a frame at the entrance of the lower codend. Separate codends for fish and Norway lobster in the same gear provide...... with hard or spiny surfaces due to successful separation of fish and Norway lobster into the upper and lower codends, respectively, and by lower catch weight in the upper codend of the test codend compared with the standard codend. The decrease in damages may also improve quality indirectly by inflicting...

Juvenile Residential Facility Census, 2010: Selected Findings. Juvenile Offenders and Victims: National Report Series. Bulletin NCJ 241134

Science.gov (United States)

Hockenberry, Sarah; Sickmund, Melissa; Sladky, Anthony

2013-01-01

This bulletin is part of the "Juvenile Offenders and Victims National Report Series." The "National Report" offers a comprehensive statistical overview of the problems of juvenile crime, violence, and victimization and the response of the juvenile justice system. During each interim year, the bulletins in the "National…

Fine-scale environmental effects on Cape hake survey catch rates in the Northern Benguela, using data from a trawl-mounted instrument package

DEFF Research Database (Denmark)

Kainge, Paulus Inekela; Wieland, Kai

2017-01-01

We investigated fine-scale effects of environmental variables associated with habitat distribution for 4 size groups of Cape hakes, Merluccius capensis and M. paradoxus, using generalized additive models (GAMs) with a negative binominal error distribution. This study took place during the Namibian...... hake trawl survey of 2016, and was made possible for the first time in Namibia by collecting oceanographic information with a trawl-mounted instrument package concurrently with the catch data. Depth, geographical position, bottom oxygen and bottom temperature had the most pronounced effect on the catch...... rates of both hake species, whereas solar zenith angle representing diel effects and surface layer chlorophyll appeared to be less important. The explained deviance for the best models ranged from 71.4% for M. capensis to 92.7% for M. paradoxus between 43 and 57 cm in length. Differences in catch rates...

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…

Vibrios associated with mortality in cultured plaice Pleuronectes platessa fry

DEFF Research Database (Denmark)

Pedersen, Karl; Austin, B.; Austin, D.A.

1999-01-01

is as yet uncertain. Selected isolates were tested for Virulence to salmon and turbot. When injected into juvenile salmonid fish, the recorded LD50 values were higher than 10(6), indicating that their virulence was relatively low. However, virulence seemed to deteriorate upon subculturing, and therefore...

Juvenile Angiofibroma: Evolution of Management

Science.gov (United States)

Nicolai, Piero; Schreiber, Alberto; Bolzoni Villaret, Andrea

2012-01-01

Juvenile angiofibroma is a rare benign lesion originating from the pterygopalatine fossa with distinctive epidemiologic features and growth patterns. The typical patient is an adolescent male with a clinical history of recurrent epistaxis and nasal obstruction. Although the use of nonsurgical therapies is described in the literature, surgery is currently considered the ideal treatment for juvenile angiofibroma. Refinement in preoperative embolization has provided significant reduction of complications and intraoperative bleeding with minimal risk of residual disease. During the last decade, an endoscopic technique has been extensively adopted as a valid alternative to external approaches in the management of small-intermediate size juvenile angiofibromas. Herein, we review the evolution in the management of juvenile angiofibroma with particular reference to recent advances in diagnosis and treatment. PMID:22164185

Juvenile Angiofibroma: Evolution of Management

Directory of Open Access Journals (Sweden)

Piero Nicolai

2012-01-01

Full Text Available Juvenile angiofibroma is a rare benign lesion originating from the pterygopalatine fossa with distinctive epidemiologic features and growth patterns. The typical patient is an adolescent male with a clinical history of recurrent epistaxis and nasal obstruction. Although the use of nonsurgical therapies is described in the literature, surgery is currently considered the ideal treatment for juvenile angiofibroma. Refinement in preoperative embolization has provided significant reduction of complications and intraoperative bleeding with minimal risk of residual disease. During the last decade, an endoscopic technique has been extensively adopted as a valid alternative to external approaches in the management of small-intermediate size juvenile angiofibromas. Herein, we review the evolution in the management of juvenile angiofibroma with particular reference to recent advances in diagnosis and treatment.

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...

Stock Assessment of Columbia River Anadromous Salmonids : Final Report, Volume I, Chinook, Coho, Chum and Sockeye Salmon Summaries.

Energy Technology Data Exchange (ETDEWEB)

Howell, Philip J.

1986-07-01

The purpose was to identify and characterize the wild and hatchery stocks of salmon and steelhead in the Columbia River Basin on the basis of currently available information. This report provides a comprehensive compilation of data on the status and life histories of Columbia Basin salmonid stocks.

Monitoring of downstream salmon and steelhead at federal hydroelectric facilities - 1996. Annual report

International Nuclear Information System (INIS)

Martinson, R.D.; Graves, R.J.; Mills, R.B.; Kamps, J.W.

1997-08-01

The seaward migration of juvenile salmonids was monitored by the National Marine Fisheries Service (NMFS) at Bonneville and John Day Dams on the Columbia River in 1996 The NMFS Smolt Monitoring Project is part of a larger Smolt Monitoring Program (SMP) coordinated by the Fish Passage Center (FPC) for the Columbia Basin Fish and Wildlife Authority. The purpose of the SMP is to monitor the migration of the juvenile salmonid stocks in the Columbia basin and make flow and spill recommendations designed to facilitate fish passage. Data are also used for travel time, migration timing, and relative run size analysis. The purpose of the NMFS portion of the program is to provide the FPC with species and project specific real time data from John Day and Bonneville Dams. Monitoring data collected included: river conditions; total numbers of fish; numbers of fry, adult salmon, and incidental catch; daily and seasonal passage patterns; and fish condition. 10 refs., 16 figs., 5 tabs

Monitoring of downstream salmon and steelhead at Federal hydroelectric facilities. Annual report 1993

International Nuclear Information System (INIS)

Wood, L.A.; Martinson, R.D.; Graves, R.J.; Carroll, D.R.; Killins, S.D.

1994-04-01

The seaward migration of juvenile salmonids was monitored by the National Marine Fisheries Service (NMFS) at Bonneville and John Day Dams on the Columbia River in 1993 (river mile 145 and 216, respectively, Figure 1). The NMFS Smolt Monitoring Project is part of a larger Smolt Monitoring Program (SMP) coordinated by the Fish Passage Center (FPC) for the Columbia Basin Fish and Wildlife Authority. This program is carried out under the auspices of the Northwest Power Planning Council Fish and Wildlife Program and is funded by the Bonneville Power Administration. The purpose of the SMP is to index Columbia Basin juvenile salmonid stocks and develop and implement flow and spill requests intended to facilitate fish passage. Data is also used for travel time, migration timing and relative run size magnitude analysis. The purpose of the NMFS portion of the program is to provide FPC with species specific data; numbers, condition, length, brand recaptures and flow data from John Day, and Bonneville Dams on a daily basis

Sexual segregation in juvenile New Zealand sea lion foraging ranges: implications for intraspecific competition, population dynamics and conservation.

Directory of Open Access Journals (Sweden)

Elaine S Leung

Full Text Available Sexual segregation (sex differences in spatial organisation and resource use is observed in a large range of taxa. Investigating causes for sexual segregation is vital for understanding population dynamics and has important conservation implications, as sex differences in foraging ecology may affect vulnerability to area-specific human activities. Although behavioural ecologists have proposed numerous hypotheses for this phenomenon, the underlying causes of sexual segregation are poorly understood. We examined the size-dimorphism and niche divergence hypotheses as potential explanations for sexual segregation in the New Zealand (NZ sea lion (Phocarctos hookeri, a nationally critical, declining species impacted by trawl fisheries. We used satellite telemetry and linear mixed effects models to investigate sex differences in the foraging ranges of juvenile NZ sea lions. Male trip distances and durations were almost twice as long as female trips, with males foraging over the Auckland Island shelf and in further locations than females. Sex was the most important variable in trip distance, maximum distance travelled from study site, foraging cycle duration and percent time at sea whereas mass and age had small effects on these characteristics. Our findings support the predictions of the niche divergence hypothesis, which suggests that sexual segregation acts to decrease intraspecific resource competition. As a consequence of sexual segregation in foraging ranges, female foraging grounds had proportionally double the overlap with fisheries operations than males. This distribution exposes female juvenile NZ sea lions to a greater risk of resource competition and bycatch from fisheries than males, which can result in higher female mortality. Such sex-biased mortality could impact population dynamics, because female population decline can lead to decreased population fecundity. Thus, effective conservation and management strategies must take into account

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,...

Influence of infection with Renibacterium salmoninarum on susceptibility of juvenile spring chinook salmon to gas bubble trauma

Science.gov (United States)

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

1999-01-01

During experiments in our laboratory to assess the progression and severity of gas bubble trauma (GBT) in juvenile spring chinook salmon Oncorhynchus tshawytscha, we had the opportunity to assess the influence of Renibacterium salmoninarum (Rs), the causative agent of bacterial kidney disease, on the susceptibility of salmon to GBT. We exposed fish with an established infection of Rs to 120% total dissolved gas (TDG) for 96 h and monitored severity of GBT signs in the fins and gills, Rs infection level in kidneys by using an enzyme-linked immunosorbent assay (ELISA), and mortality. Mortality occurred rapidly after exposure to 120% TDG, with a LT20 (time necessary to kill 20% of the population) of about 37 h, which is at a minimum about 16% earlier than other bioassays we have conducted using fish that had no apparent signs of disease. Fish that died early (from 31 to 36 h and from 49 to 52 h) had significantly higher infection levels (mean ?? SE ELISA absorbance = 1.532 ?? 0.108) than fish that survived for 96h (mean ?? SE ELISA absorbance = 0.828 ?? 0.137). Fish that died early also had a significantly greater number of gill filaments occluded with bubbles than those that survived 96 h. Conversely, fish that survived for 96 h had a significantly higher median fin severity ranking than those that died early. Our results indicate that fish with moderate to high levels of Rs infection are more vulnerable to the effects of dissolved gas supersaturation (DGS) and die sooner than fish with lower levels of Rs infection. However, there is a substantial amount of individual variation in susceptibility to the apparent cumulative effects of DGS and Rs infection. Collectively, our findings have important implications to programs designed to monitor the prevalence and severity of GBT in juvenile salmonids in areas like the Columbia River basin and perhaps elsewhere.

Copper, cadmium, and zinc concentrations in juvenile Chinook salmon and selected fish-forage organisms (aquatic insects) in the upper Sacramento River, California

Science.gov (United States)

Saiki, Michael K.; Martin, Barbara A.; Thompson, Larry D.; Walsh, Daniel

2001-01-01

This study assessed the downstream extent andseverity of copper (Cu), cadmium (Cd), and zinc (Zn)contamination from acid mine drainage on juvenile chinook salmon(Oncorhynchus tshawytscha) and aquatic insects over aroughly 270-km reach of the Sacramento River below KeswickReservoir. During April–May 1998, salmon were collected fromfour sites in the river and from a fish hatchery that receiveswater from Battle Creek. Salmon from river sites were examinedfor gut contents to document their consumption of variousinvertebrate taxa, whereas salmon from river sites and thehatchery were used for metal determinations. Midge(Chironomidae) and caddisfly (Trichoptera) larvae and mayfly(Ephemeroptera) nymphs were collected for metal determinationsduring April–June from river sites and from Battle and Buttecreeks. The fish hatchery and Battle and Butte creeks served asreference sites because they had no history of receiving minedrainage. Salmon consumed mostly midge larvae and pupae (44.0%,damp-dry biomass), caddisfly larvae (18.9%), Cladocera (5.8%),and mayfly nymphs (5.7%). These results demonstrated thatinsects selected for metal determinations were important as fishforage. Dry-weight concentrations of Cu, Cd, and Zn weregenerally far higher in salmon and insects from the river thanfrom reference sites. Within the river, high metalconcentrations persisted as far downstream as South Meridian (thelowermost sampling site). Maximum concentrations of Cd (30.7 μg g-1) and Zn (1230 μg g-1),but not Cu (87.4 μg g-1), in insects exceeded amounts that other investigators reported as toxic when fed for prolonged periods to juvenile salmonids.

Juvenile polyposis syndrome

OpenAIRE

Hsiao, Yi-Han; Wei, Chin-Hung; Chang, Szu-Wen; Chang, Lung; Fu, Yu-Wei; Lee, Hung-Chang; Liu, Hsuan-Liang; Yeung, Chun-Yan

2016-01-01

Abstract Background: Juvenile polyposis syndrome, a rare disorder in children, is characterized with multiple hamartomatous polyps in alimentary tract. A variety of manifestations include bleeding, intussusception, or polyp prolapse. In this study, we present an 8-month-old male infant of juvenile polyposis syndrome initially presenting with chronic anemia. To the best of our knowledge, this is the youngest case reported in the literature. Methods: We report a rare case of an 8-month-old male...

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.

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

Science.gov (United States)

Matthew R. Sloat; Gordon H. Reeves

2014-01-01

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

Social and psychological aspects of criminal juvenile justice in the world practice (Anglo-Saxon model of juvenile justice

Directory of Open Access Journals (Sweden)

D.S. Oshevsky

2013-10-01

Full Text Available The article is the final part of the review of existing foreign models of juvenile criminal justice system. We analyze the principles of juvenile justice in the criminal trial: protective orientation, personalization and social richness of the trial, the emphasis on educational influences. We present the foreign experience of incorporating social, psychological and clinical special knowledge into specialized justice concerning juvenile offenders. We analyze modern trends in the development of juvenile justice in the United States and Canada. We present material related to methods of risk assessment of re-offending among adolescents. We highlight approaches to complex long-term follow-up of juvenile offenders in Anglo-Saxon juvenile justice. We describe some aspects of the probation service using the method of case management. In the context of the accepted “National Strategy for Action for the Benefit of Children for 2012-2017”, the prospects for the development of specialized criminal justice for young offenders in the Russian Federation are discussed

Juvenile polyposis syndrome

Science.gov (United States)

Hsiao, Yi-Han; Wei, Chin-Hung; Chang, Szu-Wen; Chang, Lung; Fu, Yu-Wei; Lee, Hung-Chang; Liu, Hsuan-Liang; Yeung, Chun-Yan

2016-01-01

Abstract Background: Juvenile polyposis syndrome, a rare disorder in children, is characterized with multiple hamartomatous polyps in alimentary tract. A variety of manifestations include bleeding, intussusception, or polyp prolapse. In this study, we present an 8-month-old male infant of juvenile polyposis syndrome initially presenting with chronic anemia. To the best of our knowledge, this is the youngest case reported in the literature. Methods: We report a rare case of an 8-month-old male infant who presented with chronic anemia and gastrointestinal bleeding initially. Panendoscopy and abdominal computed tomography showed multiple polyposis throughout the entire alimentary tract leading to intussusception. Technetium-99m-labeled red blood cell (RBC) bleeding scan revealed the possibility of gastrointestinal tract bleeding in the jejunum. Histopathological examination on biopsy samples showed Peutz-Jeghers syndrome was excluded, whereas the diagnosis of juvenile polyposis syndrome was established. Results: Enteroscopic polypectomy is the mainstay of the treatment. However, polyps recurred and occupied the majority of the gastrointestinal tract in 6 months. Supportive management was given. The patient expired for severe sepsis at the age of 18 months. Conclusion: Juvenile polyposis syndrome is an inherited disease, so it is not possible to prevent it. Concerning of its poor outcome and high mortality rate, it is important that we should increase awareness and education of the parents at its earliest stages. PMID:27631205

Acupuntura em adolescentes com fibromialgia juvenil Acupuntura en adolescentes con fibromialgia juvenil Acupuncture in adolescents with juvenile fibromyalgia

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Marialda Höfling P. Dias

2012-01-01

Full Text Available OBJETIVO: Descrever a utilização da acupuntura em adolescentes com fibromialgia juvenil. MÉTODOS: Estudo retrospectivo realizado em pacientes com fibromialgia juvenil (critérios do Colégio Americano de Reumatologia submetidos a, pelo menos, 11 sessões semanais de acupuntura. As avaliações antes e após acupuntura incluíram dados demográficos, características da dor musculoesquelética, número de pontos dolorosos (NPD, escala visual analógica (EVA de dor, algiometria e índice miálgico (IM. Durante o estudo, os pacientes puderam usar analgésicos, amitriptilina e foram orientados a praticar atividade física aeróbica. Os resultados antes e após acupuntura foram comparados pelo teste não paramétrico de Wilcoxon. RESULTADOS: Dos 38 pacientes com fibromialgia juvenil acompanhados em oito anos consecutivos, 13 tinham todas as informações nos prontuários e nas fichas de acupuntura e foram avaliados. Destes 13, sete obtiveram melhora nos três parâmetros analisados (número de pontos dolorosos, EVA de dor e IM. As medianas do número de pontos dolorosos e da EVA de dor foram significativamente maiores antes do tratamento quando comparados ao final do tratamento com as sessões de acupuntura [14 (11-18 versus 10 (0-15, p=0,005; 6 (2-10 versus 3 (0-10, p=0,045; respectivamente]. Em contraste, a mediana do IM foi significativamente menor antes do tratamento [3,4 (2,49-4,39 versus 4,2 (2,71-5,99, p=0,02]. Nenhum dos pacientes com fibromialgia juvenil apresentou eventos adversos associados à acupuntura. CONCLUSÕES: Acupuntura é uma modalidade de Medicina Tradicional Chinesa que pode ser utilizada nos pacientes pediátricos com fibromialgia. Futuros estudos controlados serão necessários.OBJETIVO: Describir el uso de acupuntura en adolescentes con fibromialgia juvenil. MÉTODOS: Estudio retrospectivo realizado en pacientes con fibromialgia juvenil (criterios del Colegio Americano de Reumatología sometidos a al menos 11 sesiones

A comparison of single-suture and double-suture incision closures in seaward-migrating juvenile Chinook salmon implanted with acoustic transmitters: implications for research in river basins containing hydropower structures

Energy Technology Data Exchange (ETDEWEB)

Brown, Richard S.; Deters, Katherine A.; Cook, Katrina V.; Eppard, M. B.

2013-07-15

Reductions in the size of acoustic transmitters implanted in migrating juvenile salmonids have resulted in the ability to make shorter incisions that may warrant using only a single suture for closure. However, it is not known if one suture will sufficiently hold the incision closed, particularly when outward pressure is placed on the surgical site such as when migrating fish experience pressure changes associated with passage at hydroelectric dams. The objective of this research was to evaluate the effectiveness of single-suture incision closures on juvenile Chinook salmon (Oncorhynchus tshawytscha). Juvenile Chinook salmon were surgically implanted with a 2012 Juvenile Salmon Acoustic Telemetry System (JSATS) transmitter (0.30 g) and a passive integrated transponder tag (0.10 g) and incisions were closed with either one suture or two sutures. Mortality and tag retention were monitored and fish were examined after 7 and 14 days to evaluate tissue responses. In a separate experiment, surgically implanted fish were exposed to simulated turbine passage and then examined for expulsion of transmitters, expulsion of viscera through the incision, and mortal injury. With incisions closed using a single suture, there was no mortality or tag loss and similar or reduced tissue reaction compared to incisions closed with two sutures. Further, surgery time was significantly reduced when one suture was used, which leads to less handling and reduced stress. No tags were expelled during pressure scenarios and expulsion of viscera only occurred in two non-mortally injured fish (5%) with single sutures that were also exposed to very high pressure changes. No viscera expulsion was present in fish exposed to pressure scenarios likely representative of hydroturbine passage at many Columbia River dams (e.g. <2.7 ratio of pressure change; an acclimation pressure of 146.2 absolute kpa and a lowest exposure pressure of ~ 53.3 absolute kpa). Based on these results, we recommend the use of a

Development of a low commercial value fish-sausage from the fish trawling “mix” category

Directory of Open Access Journals (Sweden)

Juliana de Lima Brandão GUIMARÃES

2018-05-01

Full Text Available Abstract The decreasing stock of the main species consumed in Brazil has stimulated studies regarding the use and development of products using low commercial value species. The shrimp trawling modality produces a large volume of a “mix” category comprising low commercial value fish. However, it is necessary to develop products with greater practicality to meet the current demands of the Brazilian consumer. The aim of the present study was to develop a sausage using a low commercial value fish, the Brazilian flathead (Percophis brasiliensis , caught in the fish trawling “mix” category landed in Niterói/RJ, and perform physico-chemical, microbiological, toxicological and sensorial analyses. The centesimal composition of the analyzed fish were as follows: humidity 73.78%, proteins 16.17%, carbohydrates 3.75%, total lipids 4.41% and ash 1.78%. The microbiological and toxicological results were within the legislation standards. Twenty varieties of fatty acids (AG were detected, with the most frequent being palmitic acid (22.81%. Among the omega-3 series, the most frequent were eicosapentaenoic acid (5.36% and docosahexaenoic acid (15.95%. Regarding minerals, the most noteworthy were sodium, calcium and iron (1114.24 mg, 112.32 mg and 1.73 mg respectively. The sausage showed 87.30% acceptability. The results demonstrate that the low commercial value fish Brazilian flathead resulted in a viable product for use in fish technology, with excellent nutritional results.

Effects of riparian canopy opening and salmon carcass addition on the abundance and growth of resident salmonids

Science.gov (United States)

Margaret A. Wilzbach; Bret C. Harvey; Jason L. White; Rodney J. Nakamoto

2005-01-01

We studied the concurrent effects of riparian canopy opening and salmon carcass addition on salmonid biomass, density and growth rates in small streams over 2 years. In each of six streams in the Smith and Klamath River basins in northern California, red alder (Alnus rubra) and other hardwoods were removed along both banks of a 100-m reach to...

The vertical distribution of fish in the open water area of a deep temperate mesotrophic lake assessed by hydroacoustics and midwater trawling

Czech Academy of Sciences Publication Activity Database

Jůza, Tomáš; Frouzová, Jaroslava; Brämick, U.; Draštík, Vladislav; Mrkvička, Tomáš; Kubečka, Jan

2012-01-01

Roč. 97, č. 6 (2012), s. 509-525 ISSN 1434-2944 R&D Projects: GA AV ČR(CZ) IAA600960901 Institutional support: RVO:60077344 Keywords : smelt * vendace * trawling * hydroacoustics * Lake Werbellin Subject RIV: EH - Ecology, Behaviour Impact factor: 0.870, year: 2012

Determining the impacts of trawling on benthic function in European waters : a biological traits approach

DEFF Research Database (Denmark)

Bolam, Stefan; Kenny, Andrew; Garcia, Clement

characteristics, have allowed us to better understand the interactions between the benthic fauna and their environment at a functional level. We present the initial findings of work conducted under the auspices of the EU-funded project ‘BENTHIS’ which aims to improve our understanding of the impacts of trawling...... on benthic ecosystem functioning over much larger spatial scales than previously undertaken. Biological traits information from 887 stations across European waters (Norwegian, UK, Belgian, Dutch, Danish waters, the Mediterranean and Black Sea) were analysed to: i) quantify the relationships between infaunal...

Juvenile dispersal in Calomys venustus (Muridae: Sigmodontinae)

Science.gov (United States)

Priotto, José; Steinmann, Andrea; Provensal, Cecilia; Polop, Jaime

2004-05-01

Both spacing behaviour and dispersal movement are viewed as hierarchical processes in which the effects may be expressed at spatial scale. This research was carried out to examine the hypothesis that the presence of parents promotes the dispersal of juveniles from their natal nest and their father or mother home-range, in Calomys venustus.The study was carried out in four 0.25 ha fences (two controls and two experimentals), in a natural pasture. This study had two periods: Father Removal (FR) (August and December 1997; year one) and Mother Removal (MR) (August 1998 and January 1999; year two). For the FR treatment fathers were removed after juveniles were born, but in the MR treatment mothers were removed after the juveniles were weaned. The effect of parents on the dispersal distance of juveniles was analysed with respect to their natal nest and their mother and father home-range. Dispersal distance from the nest of C. venustus was independent of either male or female parent. Juveniles were more dispersing in relation to the centre of activity of their mothers than to that of their fathers, and females were more dispersing than males. Female juveniles overlap their home-range with their parents less than male juveniles do. The differences observed between female and male juveniles would be related to their different sexual maturation times, as well as to the female territoriality.