bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Surface Trawl to Detect Migrating Juvenile Salmonids Tagged with Passive Integrated Transponder Tags
Authors: Ledgerwood Richard D. , Ryan Brad A. , Dawley Earl M. , Nunnallee Edward P. , Ferguson John W. 
Published: June 2004

Abstract
We developed a surface pair-trawl system to detect juvenile Pacific salmon Oncorhynchus spp. marked with passive integrated transponder (PIT) tags as they migrate through the upper Columbia River estuary. The trawl was fitted with a detection antenna in its cod end and was deployed by two vessels. Fish entering the trawl body exit after passing by the detection antenna. Detection data were recorded by electronic components housed in a small boat tethered to the trawl. The system was modified extensively after its first deployment in 1995 and by 2001 was performing reliably under a variety of weather conditions and river flows. From 1995 to 2001 the device detected 29,699 PIT-tagged juvenile salmon. During extended daily sampling periods, we detected nearly 2% of all PIT tags previously detected at Bonneville Dam, which is located 159 rkm upstream from the study area.
Evaluation of Dredging Effort by the Delaware Bay Oyster Fishery in New Jersey Waters
Authors: Banta Sarah E. , Powell Eric N. , Ashton-Alcox Kathryn A. 
Published: June 2004

Abstract
As part of a study to assess the effect of commercial dredging for eastern oysters Crassostrea virginica on their beds in Delaware Bay, we evaluated the total dredging effort for the Delaware Bay oyster industry in New Jersey waters for 1999-2000 and examined some of the behavioral and gear-related factors that determined this total effort. In a standard 8-h fishing day, a one-dredge boat traverses about 3.8 ha (38,000 m2) of oyster bed. A two-dredge boat traverses nearly twice that area, about 6.4 ha. Oyster boats typically fish in a single area for most of the day, yet catch per unit effort (CPUE) does not decline during the course of the day. Catch per unit effort is stable because of low dredge efficiency. Although an oyster dredge is capable of routinely achieving efficiencies of 10-60%, dredge efficiency during fishing is usually only 4-7%. Low dredge efficiency means that swept-area coverage (area of the bottom traversed by a dredge) is high for the number of oysters taken. The most heavily fished Delaware Bay oyster beds were completely dredged one to eight times in a single year. Oyster catch is typically measured in bushels (1 bushel = 35 L). The CPUE, calculated as the number of bushels of oysters caught per hectare swept by the dredge, averaged 10-12 in 1999-2000. The CPUE did not vary significantly between one- and two-dredge boats but varied by more than a factor of five among oyster beds. Nevertheless, CPUE was not correlated with the number of bushels landed from each bed. Hence, factors other than the rate of capture, such as market quality, determined the spatial distribution of fishing effort.
Reconnecting a Fragmented River: Movements of Westslope Cutthroat Trout and Bull Trout after Transport Upstream of Milltown Dam, Montana
Authors: Schmetterling David A. 
Published: June 2004

Abstract
Milltown Dam annually impedes the migration of 11 fish species, and data suggest that fish that migrate to the dam do not spawn once their migration is impeded. Densities of westslope cutthroat trout Oncorhynchus clarki lewisi and bull trout Salvelinus confluentus are low near Milltown Dam, but their annual presence at the dam suggests the potential to reestablish fluvial life history forms and enhance local or upriver populations. Operating a fish trap at Milltown Dam in 2000 and 2001, I captured westslope cutthroat trout and bull trout, implanted 42 with radio transmitters, and transported them upstream of Milltown Dam. I monitored the implanted fish to determine posttransport movements and spawning. Most of the fish captured continued upstream to spawn, and many migrations exceeded 100 km after transport. Several fish encountered pre- or postspawning problems, including entrainment in irrigation ditches, predation by nonnative northern pike Esox lucius, angler harvest, and fallback over Milltown Dam. These movements elucidate the need for comprehensive watershed-level restoration and measures to mitigate the continued effects of Milltown Dam. Whereas habitat restoration may contribute to the long-term recovery of depressed populations, adding spawning adults provides immediate benefits to the upriver populations. Because bull trout numbers in the Clark Fork River system are very low, the addition of a few individuals could significantly enhance recruitment and aid recovery. The success of capture, transport, and spawning suggests that this is an effective, albeit labor-intensive way to enhance or restore spawning individuals to populations of westslope cutthroat trout and bull trout that have been fragmented by Milltown Dam until permanent fish passage is provided.
Responses in Fish Community Structure to Restoration of Two Indiana Streams
Authors: Moerke Ashley H. , Lamberti Gary A. 
Published: June 2004

Abstract
Stream restoration has accelerated in the Midwestern United States during the past decade, but the effects of restoration on stream biota are rarely evaluated. From 1997 to 2000, we studied the responses in fish communities to the attempted restoration of two channelized streams (Juday Creek and Potato Creek) in northwestern Indiana, each of which received two new meanders to a 1-km reach of stream length. The restored meanders of Juday Creek also received major improvement to instream habitat, bank stabilization, and silt control. In contrast, Potato Creek received only reconnection of the stream to historical meanders. Fish were monitored for 3 years after reconstruction by use of electroshocking and salmonid redd surveys. In Juday Creek, trout size-class distribution broadened and redd construction increased in the restored reaches. However, most fish metrics for reconstructed reaches did not surpass the levels in the channelized reaches after 3 years. Continued sedimentation from upstream sources, which reduced habitat quality, likely counteracted the positive effects of the restoration. In contrast, unanticipated geomorphic changes in Potato Creek led to decreased current velocity and highly altered fish community structure. The American brook lamprey Lampetra appendix, a sensitive species, was not collected after restoration, and the fish community changed from rheophilic species to highly tolerant, slow-water species. Overall, changes in fish community structure revealed strengths and weaknesses in contemporary stream restoration approaches, findings that will aid future restoration efforts.
Impacts of the Columbia River Hydroelectric System on Main-Stem Habitats of Fall Chinook Salmon
Authors: Dauble D. D. , Hanrahan T. P. , Geist D. R. , Parsley M. J. 
Published: June 2004

Abstract
Salmonid habitats in main-stem reaches of the Columbia and Snake rivers have changed dramatically during the past 60 years because of hydroelectric development and operation. Only about 13% and 58% of riverine habitats in the Columbia and Snake rivers, respectively, remain. Most riverine habitat is found in the upper Snake River; however, it is upstream of Hells Canyon Dam and not accessible to anadromous salmonids. We determined that approximately 661 and 805 km of the Columbia and Snake rivers, respectively, were once used by fall chinook salmon Oncorhynchus tshawytscha for spawning. Fall chinook salmon currently use only about 85 km of the main-stem Columbia River and 163 km of the main-stem Snake River for spawning. We used a geomorphic model to identify three river reaches downstream of present migration barriers with high potential for restoration of riverine processes: the Columbia River upstream of John Day Dam, the Columbia-Snake-Yakima River confluence, and the lower Snake River upstream of Little Goose Dam. Our analysis substantiated the assertion that historic spawning areas for fall chinook salmon occurred primarily within wide alluvial floodplains, which were once common in the main-stem Columbia and Snake rivers. These areas possessed more unconsolidated sediment and more bars and islands and had lower water surface slopes than did less extensively used areas. Because flows in the main stem are now highly regulated, the predevelopment alluvial river ecosystem is not expected to be restored simply by operational modification of one or more dams. Establishing more normative flow regimes—specifically, sustained peak flows for scouring—is essential to restoring the functional characteristics of existing, altered habitats. Restoring production of fall chinook salmon to any of these reaches also requires that population genetics and viability of potential seed populations (i.e., from tributaries, tailrace spawning areas, and hatcheries) be considered.
Migration of Precocious Male Hatchery Chinook Salmon in the Umatilla River, Oregon
Authors: Zimmerman Christian E. , Wes Stonecypher R. , Hayes Michael C. 
Published: June 2004

Abstract
Between 1993 and 2000, precocious yearling males of hatchery-produced fall and spring chinook salmon Oncorhynchus tshawytscha composed 3.6-82.1% of chinook salmon runs to the Umatilla River, Oregon. These yearling males are smaller than typical jack salmon, which spend a full winter in the ocean, and are commonly referred to as “minijacks.” Minijack fall chinook salmon are characterized by enlarged testes and an increased gonadosomatic index. Our goal was to determine if minijacks migrated to saltwater between the time they are released from the hatchery and the time they return to the Umatilla River, a period of 4-6 months. During 1999-2000, we collected otoliths from an adult male fall chinook salmon, 12 spring chinook salmon minijacks, and 10 fall chinook salmon minijacks. We measured strontium:calcium (Sr:Ca) ratios from the age-1 annulus to the edge of the otolith to determine whether these fish had migrated to the ocean. The Sr:Ca ratios increased from low values near the age-1 annulus, similar to ratios expected from freshwaters, to higher values near the edge of the otolith. The Sr:Ca ratios increased to levels similar to ratios expected in saltwater, indicating that these fish had migrated to saltwater before returning to the Umatilla River. Analysis of published water chemistry data from the Columbia and Snake rivers and rearing experiments in the main-stem Columbia River confirmed that high Sr:Ca ratios measured in otoliths were not the result of high strontium levels encountered in the freshwater environment. Previously assumed to remain within freshwater and near the point of release, our results suggest these minijack salmon migrated at least 800 km and past three hydroelectric dams to reach saltwater and return to the Umatilla River.
Walleye Predation on Hatchery Releases of Kokanees and Rainbow Trout in Lake Roosevelt, Washington
Authors: Baldwin Casey M. , McLellan Jason G. , Polacek Matt C. , Underwood Keith 
Published: June 2004

Abstract
Recruitment failures of stocked kokanees (lacustrine sockeye salmon Oncorhynchus nerka) in Lake Roosevelt have led to examination of various limiting factors. We evaluated the predatory impacts of piscivores on hatchery-released and net-pen-released kokanees and rainbow trout O. mykiss from the Sherman Creek Hatchery in 1999 and 2000. We used an angler tournament to mark walleyes Stizostedion vitreum for an abundance estimate, and then used gillnetting and electrofishing to collect recaptures and monitor the diet of walleyes. A bioenergetics model was used to quantify consumption, and estimates were extrapolated to walleye abundance to determine a percent loss of hatchery fish. Kokanees averaged 22-100% of the diet contents of walleyes (&gt;300 mm total length), whereas rainbow trout averaged 0-25%, depending on location and timing following release. In 1999, we estimated that 16,610 walleyes consumed 15% of the hatchery kokanees within 41 d of release; however, our diet information did not correspond spatially with our population estimate. In 2000, we corrected our spatial bias and estimated that the population of 12,233 walleyes consumed 9.4% of the hatchery kokanees and 7.3% of the hatchery rainbow trout within 41 d of release. We conclude that the walleye population in northern Lake Roosevelt was effectively “swamped” by the biomass of salmonids released at the Sherman Creek Hatchery. However, piscivores may still limit kokanee recruitment, depending on long-term predation rates for the reservoir-wide walleye population.
Physiological Changes in Largemouth Bass Caused by Live-Release Angling Tournaments in Southeastern Ontario
Authors: Suski Cory D. , Killen Shaun S. , Morrissey Michael B. , Lund Susan G. , Tufts Bruce L. 
Published: June 2004

Abstract
Several largemouth bass Micropterus salmoides tournaments in Ontario were visited in the summers of 1999 and 2000 to examine the physiological changes that occur in largemouth bass as a result of tournament procedures. Physiological variables were compared among tournament-caught largemouth bass, resting laboratory controls, and angled controls. The plasma cortisol and glucose concentrations and plasma osmolarity in tournament-caught largemouth bass sampled within 5 min following the weigh-in were significantly greater than those in both control groups. Tournament-caught fish also exhibited ionic disturbances that involved increases in plasma sodium and potassium concentrations, but there were no significant changes in the levels of plasma chloride. Large changes in the metabolic status of largemouth bass sampled following the weigh-in included major reductions in the muscle energy stores phosphocreatine, adenosine triphosphate, and glycogen and large increases in muscle and plasma lactate concentrations. In contrast, no significant changes occurred in the mRNA levels of heat-shock protein 70 in several tissues or in plasma creatine phosphokinase activity. Taken together, these results indicate that live-release angling tournaments cause a significant physiological disturbance in largemouth bass, but there is no evidence that these events normally result in serious cell damage.
Assessment of a Constructed Fish Migration Barrier Using Radio Telemetry and Floy Tagging
Authors: Baxter James S. , Birch Gary J. , Olmsted W. R. 
Published: June 2004

Abstract
We assessed the effectiveness of a constructed fish migration barrier in the Salmo River, British Columbia, Canada, 10 years after it was constructed. The barrier was initially installed to prevent an expected increase in upstream migration of suckers Catostomus spp. and northern pikeminnow Ptychocheilus oregonensis into the Salmo River following the creation of Seven Mile Reservoir on the Pend d'Oreille River. To determine the effectiveness of the barrier, we applied radio and Floy tags to these species in Seven Mile Reservoir to assess whether upstream migration over the barrier was occurring. After sampling below the barrier, 5 largescale suckers C. macrocheilus and 5 northern pikeminnow were radio-tagged, whereas 124 suckers and 11 northern pikeminnow were Floy-tagged. Radio tracking surveys confirmed that most radio-tagged suckers and northern pikeminnow made migrations only within the reservoir, but one sucker was tracked above the barrier. This movement occurred after the peak of annual discharge. During snorkel surveys conducted above the barrier, we observed five Floy-tagged suckers. The results are discussed in relation to the use of tagging methods to monitor sucker and northern pikeminnow migrations and assess the effectiveness of constructed fish migration barriers.
Latitudinal Comparisons of Walleye Growth in North America and Factors Influencing Growth of Walleyes in Kansas Reservoirs
Authors: Quist Michael C. , Guy Christopher S. , Schultz Randall D. , Stephen James L. 
Published: June 2004

Abstract
We compared the growth of walleyes Stizostedion vitreum in Kansas to that of other populations throughout North America and determined the effects of the abundance of gizzard shad Dorosoma cepedianum and temperature on the growth of walleyes in Kansas reservoirs. Age was estimated from scales and otoliths collected from walleyes (N = 2,072) sampled with gill nets from eight Kansas reservoirs during fall in 1991-1999. Age-0 gizzard shad abundance was indexed based on summer seining information, and temperature data were obtained from the National Oceanic and Atmospheric Administration. Parameter estimates of von Bertalanffy growth models indicated that the growth of walleyes in Kansas was more similar to that of southern latitude populations (e.g., Mississippi and Texas) than to that of northern (e.g., Manitoba, Minnesota and South Dakota) or middle latitude (e.g., Colorado and Iowa) populations. Northern and middle latitude populations had lower mean back-calculated lengths at age 1, lower growth coefficients, and greater longevity than southern and Kansas populations. A relative growth index (RGI; (Lt /Ls) × 100, where Lt is the observed length at age and Ls is the age-specific standard length derived from a pooled von Bertalanffy growth model) and standardized percentile values (percentile values of mean back-calculated lengths at age) indicated that the growth of walleyes in Kansas was above average compared with that of other populations in North America. The annual growth increments of Kansas walleyes were more variable among years than among reservoirs. The growth increments of age-0 and age-1 walleyes were positively related to the catch rates of gizzard shad smaller than 80 mm, whereas the growth of age-2 and age-3 walleyes was inversely related to mean summer air temperature. Our results provide a framework for comparing North American walleye populations, and our proposed RGI provides a simple, easily interpreted index of growth.
Postharvest Length Changes of Angler-Caught Walleyes
Authors: Blackwell Brian G. , Hubers Matthew J. , Losco Robert G. 
Published: June 2004

Abstract
Information concerning postharvest changes in fish length is important in the enforcement of length-based regulations. We evaluated whether the total length of walleye Stizostedion vitreum changed following angler harvest and being frozen. Walleyes were collected by angling during open-water periods at various water temperatures and during ice cover. To simulate angler practices, postharvest walleyes were placed in a cooler containing ice or in a live well. Postharvest, open-water-collected walleyes were measured at 1-h intervals through 10 h, at 20 h, and after 30 d of frozen storage. Walleyes collected during ice fishing were measured through 36 h, at 44 h, and after 30 d of frozen storage. All collected walleyes were frozen for 30 d because it is often the time period that fish are held before being introduced as evidence in court. Postharvest walleyes held in a cooler tended to lose length, the greatest decrease occurring from those collected at the coldest water temperatures. A two-way analysis of variance (ANOVA) indicated that both water temperature and time had significant (P &lt; 0.05) influence on total length changes for open-water-caught walleyes stored in coolers. Length change was minimal for walleyes held in live wells. While measurement time was not significant, water temperature significantly influenced the length change of walleyes held in a live well. Length changes for walleyes caught through the ice were similar to the changes observed for cooler-held fish caught at the coldest open-water temperature (10°C), but the amount of time required for change to occur was longer. Walleyes held in frozen storage generally exhibited a significant decrease in total length from the time of capture. Enforcement personnel should be aware of the potential length changes walleyes may exhibit while stored by anglers.
Effect of Pectoral Fin Ray Removal on Station-Holding Ability of Shovelnose Sturgeon
Authors: Parsons Glenn R. , Jeffrey Hoover Jan , Jack Killgore K. 
Published: June 2004

Abstract
The effect of fin ray removal on swimming performance was evaluated for shovelnose sturgeon Scaphirhynchus platorynchus from the lower Mississippi River. Immediately upon collection, the marginal pectoral fin ray was removed from some fish, and others were left unclipped as a control group. Fish were promptly returned to the laboratory and held in 1,300-L recirculating tanks at 21-26°C. After a minimum recovery time of 48 h, individual fish were placed in a 1,000-L, Brett-type swim tunnel, and their ability to maintain station in flowing water by swimming, skimming, or substrate appression was tested by subjecting fish to increasing speeds beginning at 10 cm/s. After a 60-min swimming bout, speed was increased by 10 cm/s. This was repeated until the fish could no longer maintain station. Fin ray removal had no significant effect on critical station-holding speed (CSHS). The CSHS (mean ± SE) of fin-ray clipped fish was 60.1 ± 4.2 cm/s, and that of unclipped fish was 59.2 ± 3.0 cm/s. Correlation analysis and analysis of variance indicated that collection method, water temperature, size of fish, and time spent in the laboratory had no significant effects on CSHS. Tail beat frequency increased with water velocity, but clipped and unclipped fish were not significantly different. Results indicate that removal of the pectoral fin ray has little or no effect on station-holding ability in shovelnose sturgeon.
Spatial Changes in Trawl Fishing Effort in Response to Footrope Diameter Restrictions in the U.S. West Coast Bottom Trawl Fishery
Authors: Hannah Robert W. 
Published: June 2004

Abstract
Changes in the spatial distribution of U.S. west coast bottom-trawl effort in relation to areas of prime habitat for rockfish Sebastes spp. were evaluated between 1992 and 2001. Prime trawlable rockfish habitat (PTRH) was defined based on the spatial distribution of high rockfish catches from logbook data for 1992-1995. Bottom-trawl effort was sharply reduced within PTRH after the establishment of maximum trawl footrope diameter restrictions in 2000. However, reductions in rockfish catch limits prior to 2000 had already reduced trawl activity within these areas, confounding the effects of reduced trip limits and footrope diameter restrictions. Fishing inside PTRH rebounded in 2001, when retention limits for yellowtail rockfish Sebastes flavidus as flatfish bycatch were raised, suggesting that limits may be as important as gear restrictions in determining the spatial distribution of trawl effort in this fishery. The untrawled area of PTRH between 43°N and 48°N in 2000-2001 was estimated at about 186,000 ha.
Standard Weight (Ws) Equations for Four Rare Desert Fishes
Authors: Didenko Alexander V. , Bonar Scott A. , Matter William J. 
Published: June 2004

Abstract
Standard weight (Ws) equations have been used extensively to examine body condition in sport fishes. However, development of these equations for nongame fishes has only recently been emphasized. We used the regression-line-percentile technique to develop standard weight equations for four rare desert fishes: flannelmouth sucker Catostomus latipinnis, razorback sucker Xyrauchen texanus, roundtail chub Gila robusta, and humpback chub G. cypha. The Ws equation for flannelmouth suckers of 100–690 mm total length (TL) was developed from 17 populations: log10 Ws = −5.180 + 3.068 log10TL. The Ws equation for razorback suckers of 110–885 mm TL was developed from 12 populations: log10 Ws = −4.886 + 2.985 log10TL. The Ws equation for roundtail chub of 100–525 mm TL was developed from 20 populations: log10 Ws = −5.065 + 3.015 log10TL. The Ws equation for humpback chub of 120– 495 mm TL was developed from 9 populations: log10 Ws = −5.278 + 3.096 log10TL. These equations meet criteria for acceptable standard weight indexes and can be used to calculate relative weight, an index of body condition.