bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors Affecting Walleye Catch in Short-Term Gill-Net Sets in a Large Minnesota Lake
Authors: Schmalz Patrick J. , Staples David F. 
Published: December 2011

Abstract
Gill nets are a versatile fish sampling gear used for many species and habitats; however, their usefulness may be limited by selectivity patterns and reliance on fish movement, which can be influenced by several factors. We evaluated the effect of net length, time of day, sampling date, surface water temperature, soak time, water depth, and location on the number, length, and initial mortality of walleyes Sander vitreus caught in short-term (mean, 38.8 min; range, 10–200 min) gill nets set in Mille Lacs Lake, Minnesota. The number of walleyes caught was best described by a generalized additive model (GAM) that contained all seven covariates and explained 35% of the variation in catch. The length of walleyes caught was best described by a GAM that contained time of day, sampling date, soak time, and sampling location as covariates and explained 11% of the variation in fish length. The initial mortality of walleyes was best described by a GAM that included surface water temperature and soak time as covariates. Walleye catches were higher from dusk to dawn than at other times, with peak catches occurring around 0500 and 2100 hours, demonstrating the diel activity patterns of walleyes. Catches also increased with surface water temperature and soak time. However, the initial mortality of walleyes also increased with surface water temperature and soak time, with the largest increase in initial mortality at soak times longer than 60 min. Investigators can use these results to assist in designing and planning short-term gill-netting efforts to maximize the catch and minimize the mortality of walleyes.
Received June 23, 2010; accepted October 22, 2010
Development of a Riverine Index Netting Protocol: Comparisons of Net Orientation, Height, Panel Order, and Line Diameter
Authors: Jones Nicholas E. , Yunker Geoffrey B. 
Published: December 2011

Abstract
We developed a gillnetting protocol by sampling 17 nonwadeable rivers across northern Ontario over the course of four summers from 2005 to 2008. The rivers represented a range of habitats; however, all had a coolwater to warmwater fish community characterized by walleyes Sander vitreus, northern pike Esox lucius, white suckers Catostomus commersonii, yellow perch Perca flavescens, and smallmouth bass Micropterus dolomieu. During the study, three net designs were used. Each net had one to four configurations that varied in height, length, monofilament diameter, and sequence of the mesh sizes. We found that most fish (87%) were captured in the lower half of 1.8-m-high gill nets and that there was no difference in catch between gill nets with serial panels (i.e., sequentially increasing mesh sizes) and those with randomly organized panels. Net that were set perpendicular to shore or angled to shore caught approximately twice as many fish as nets that were set parallel to shore. Contrary to expectations, there were no differences in net durability and catch between thick- and thin-diameter monofilament nets. Based on the results of these experiments, we propose an improved net design that we call the large-mesh riverine index net for use in rivers; it is more versatile, reduces net drag, and fishes more effectively than the traditional gill nets that are used in lakes. The large-mesh riverine index net has eight panels (3.1 m long × 0.9 m high) and totals 24.8 m in length. Panel stretch measures (and the random order used) for this design are 127, 76, 178, 25, 102, 203, 51, and 152 mm. The nets are set perpendicular to shore in rivers from July 1 to October 1 and should be fished in areas where water velocity is less than 0.1 m/s.
Received January 12, 2010; accepted November 2, 2010
Sensitivity of Recreational Access to Reservoir Water Level Variation: An Approach to Identify Future Access Needs in Reservoirs
Authors: Daugherty Daniel J. , Buckmeier David L. , Kokkanti Praveen K. 
Published: December 2011

Abstract
Reservoirs support popular sport fisheries and other forms of water recreation. However, access to these systems is often sensitive to variation in water level. Increasing water demands due to population growth and the effects of climate change suggest that maintaining adequate recreational access to reservoirs will become increasingly difficult. Knowledge of the effects of water level variation on boat and shoreline access is required to identify future needs and to aid in prioritizing improvement efforts that promote participation in fishing and aquatic recreation. To address this need, we developed a geographical information systems-based approach to quantify the effects of reservoir water level variation on recreational access and applied the technique to three Colorado River reservoirs in Texas: Lake Buchanan, Lake Travis, and Lyndon B. Johnson Reservoir. The data were used to identify reservoir-specific water levels (m below full pool) at which the availability of access was adversely affected. For the three reservoirs, 33–39% of boat access sites were dewatered with 1–3-m reductions in water level, over 50% of access sites were unusable with an additional 1–2-m loss of water level (i.e., 2–4-m reductions), and over 75% of access sites were lost with 4–8-m reductions in water level. The effect of water level reductions was less for shoreline access than for boat access. Historic water levels in each reservoir were then compared with a regional water availability model to estimate future trends in access for each reservoir. Reservoirs exhibited contrasting trends in future accessibility, ranging from a 92–500% decrease in access for Lake Buchanan to a 5–31% increase for Lake Travis. The techniques developed in this study will assist fisheries managers in working with water authorities and policy makers to minimize, mitigate, or prevent negative effects on recreational access and will aid in identifying and prioritizing reservoirs that require future access improvements.
Received June 25, 2010; accepted December 27, 2010
Performance of Diploid and Triploid Rainbow Trout Stocked in Idaho Alpine Lakes
Authors: Koenig Martin K. , Kozfkay Joseph R. , Meyer Kevin A. , Schill Daniel J. 
Published: December 2011

Abstract
Increased growth, improved survival, and genetic protection of wild stocks have been suggested as benefits of stocking triploid (i.e., sterile) salmonids for recreational fisheries. We examined the return rates and growth of mixed-sex diploid (2N), mixed-sex triploid (3N), and all-female triploid (AF3N) rainbow trout Oncorhynchus mykiss across 28 alpine lakes. Equal numbers of each treatment group were stocked in 2001 and 2003 and sampled 3–4 years later. During 2004 and 2005, a total of 75 2N and 36 3N marked rainbow trout were recaptured. Taken together, the 2N fish accounted for an average of 0.68 of the total marked fish caught, and the combined proportions of test fish (including netting and angling) differed significantly between the test groups and were consistent across survey years. During 2006 and 2007, a total of 60 2N, 31 3N, and 208 AF3N marked rainbow trout were recaptured. The mean length of the test fish was similar between test groups within sampling years. Overall, the return of 3N rainbow trout to alpine lakes in Idaho was low compared with that of 2N trout, whereas AF3N trout appeared to return in higher proportions than both of the other groups. The triploid stocks studied in this evaluation did not show any growth advantages over the duration of the study. Study design limitations may have contributed in part to some of the differences in the number of 2N and 3N rainbow trout captured. However, our results suggest that fisheries managers should consider all-female triploid rainbow trout as a low-risk option for maintaining alpine lake fisheries while minimizing the impact on native stocks.
Received January 27, 2010; accepted November 16, 2010
Recovery of Coded Wire Tags at a Caspian Tern Colony in San Francisco Bay: A Technique to Evaluate Impacts of Avian Predation on Juvenile Salmonids
Authors: Evans Allen F. , Roby Daniel D. , Collis Ken , Cramer Bradley M. , Sheggeby John A. , Adrean Lindsay J. , Battaglia Daniel S. , Lyons Donald E. 
Published: December 2011

Abstract
We recovered coded wire tags (CWTs) from a colony of Caspian terns Hydroprogne caspia on Brooks Island in San Francisco Bay, California, to evaluate predation on juvenile salmonids originating from the Sacramento and San Joaquin rivers. Subsamples of colony substrate representing 11.7% of the nesting habitat used by the terns yielded 2,079 salmonid CWTs from fish released and subsequently consumed by terns in 2008. The estimated number of CWTs deposited on the entire tern colony was 40,143 (ranging from 26,763 to 80,288), once adjustments were made to account for tag loss and the total amount of nesting habitat used by terns. Tags ingested by terns and then egested on the colony were undamaged, and the tags’ complete numeric codes were still identifiable. The CWTs found on the tern colony indicated that hatchery Chinook salmon Oncorhynchus tshawytscha trucked to and released in San Pablo Bay were significantly more likely to be consumed by Caspian terns than Chinook salmon that migrated in-river to the bay; 99.7% of all tags recovered were from bay-released Chinook salmon. Of the CWTs recovered on the tern colony, 98.0% were from fall-run Chinook salmon, indicating a higher susceptibility to tern predation than for the spring run type. None of the approximately 518,000 wild Chinook salmon that were coded-wire-tagged and released in the basin were recovered on the tern colony, suggesting that the impacts on wild, U.S. Endangered Species Act–listed Chinook salmon populations were minimal in 2008. Overall, we estimate that 0.3% of the approximately 12.3 million coded-wire-tagged Chinook salmon released in the basin in 2008 were subsequently consumed by Caspian terns from the Brooks Island colony. These results indicate that CWTs implanted in juvenile salmon can be recovered from a piscivorous waterbird colony and used to evaluate smolt losses for runs that are tagged.
Received January 25, 2010; accepted December 13, 2010
Assessing the Reliability of Fisher Self-Sampling Programs
Authors: Roman Sally , Jacobson Nikki , Cadrin Steven X. 
Published: December 2011

Abstract
The transition to catch share management for groundfish fisheries in the waters off the northeastern USA will require more monitoring than is presently obtained through traditional programs. Other types of at-sea reporting may be necessary to address data gaps and complement other sampling programs like the Northeast Fisheries Observer Program (NEFOP). Validation of fisher self-sampling programs, such as the study fleet program of the School for Marine Science and Technology (University of Massachusetts Dartmouth), provides another monitoring option to be used in conjunction with existing systems. In this paper, data from the study fleet program were compared with other fisheries-dependent data sources in the region. We tested for significant differences in catch at the trip, species, and haul levels by disposition (i.e., kept and discarded). Effort and length measurements for six commercial species were also analyzed. Catch results were mixed but similar for commercial species across comparisons. The study fleet program and NEFOP had consistent reporting in comparison with dealer landings, which are reported to the National Marine Fisheries Service by seafood dealers that are issued a federal permit to sell fish. For comparisons of catch at the haul level, there was a significant difference between NEFOP data and study fleet data; median differences were small, and the study fleet reported less catch. For commercial species, there was no significant difference in catch (except for kept catch) between the study fleet data and NEFOP data. Study fleet catch data were more comprehensive than logbook data (e.g., study fleet data included catch of bycatch species). Effort data from the study fleet were more accurate and precise than logbook data and were similar to NEFOP data. There was no statistical difference in length frequencies based on study fleet data and NEFOP data.
Received April 16, 2010; accepted November 26, 2010
Comparison of Boat Electrofishing, Trawling, and Seining for Sampling Fish Assemblages in Iowa's Nonwadeable Rivers
Authors: Neebling Travis E. , Quist Michael C. 
Published: December 2011

Abstract
The effect of reach length on species richness (estimated with boat-mounted electrofishing, a modified Missouri trawl, and a bag seine) was evaluated in Iowa's nonwadeable river systems. In 2007 and 2008, 21 reaches were sampled on 16 nonwadeable rivers throughout Iowa; reaches were 3 or 5 km in length, depending on stream order. A total of 21,197 fish from 83 species were sampled in this study. Electrofishing produced the highest number of species (65), followed by trawling (60) and seining (54). Forty-seven percent of all the species sampled in this study were captured by all three gears. Four species were captured only by the seine, 8 only by the trawl, and 13 only by electrofishing. Fish sampling data were used to evaluate gears and estimate the number of samples required to observe specified percentages of the total number of species in each reach. The minimum effort necessary to sample 90% of the species in a reach with 95% confidence was determined using a resampling procedure. Sampling with a seine was considered ineffective in nonwadeable rivers and did not substantially reduce the effort necessary to sample 90% of the species in a reach. In 3-km-long reaches, the minimum effort necessary to sample 90% of the species observed was fifteen 100-m electrofishing runs and twenty-four 50-m-long trawls. Twenty-five 100-m electrofishing runs and forty-two 50-m-long trawls were necessary to sample 90% of the species observed in 5-km-long reaches.
Received October 13, 2009; accepted January 27, 2011
A Portable Electronarcosis System for Anesthetizing Salmonids and Other Fish
Authors: Hudson J. Michael , Johnson Jeffrey R. , Kynard Boyd 
Published: December 2011

Abstract
The physiological responses of fish to continuous (nonpulsed) direct current were first described in the 1960s. One of these responses, electronarcosis (anesthesia, accompanied by muscle relaxation, through electrical inhibition), has been used in fisheries research and management as an anesthetic since the 1970s. We provide details on the assembly and operation of a portable electronarcosis unit for fish anesthesia and describe its performance with respect to two species of salmonids. The portability and effectiveness of this approach make electronarcosis a viable alternative to existing anesthetics that can be used for a number of applications.
Received June 8, 2010; accepted January 27, 2011
Postrelease Survival of Sublegal Southern Flounder Captured in a Commercial Gill-Net Fishery
Authors: Smith William E. , Scharf Frederick S. 
Published: December 2011

Abstract
Discards from commercial fisheries may be subject to high rates of mortality that vary over time and space, contributing to inaccuracies in stock assessments. We present the results from a field experiment in the New River estuary, North Carolina, designed to estimate the postrelease survival of commercially gill-netted, sublegal southern flounder Paralichthys lethostigma. Large, replicate field enclosures were used to monitor gill-netted southern flounder for a 3-d period after capture. The survival of observed discards showed significant variation among seasons. During fall and spring, overall survival was estimated to fall between 0.74 and 0.87, while during summer survival was estimated to fall between 0.22 and 0.30 and included fish that were dead when gill nets were retrieved. Logistic regression analysis was used to evaluate the relative effects of individual traits on the postrelease survival of southern flounder in the commercial gill-net fishery. Model selection indicated that season and fish condition were the best characteristics with which to predict postrelease survival and that body size may also influence postrelease survival. Low seasonal estimates of the survival of discarded southern flounder suggest that management measures that mitigate poor discard survival will be most effective during the summer.
Received November 11, 2010; accepted February 17, 2011
Spring Capture Site Fidelity of Adult Muskellunge in Inland Lakes
Authors: Jennings Martin J. , Hatzenbeler Gene R. , Kampa Jeffrey M. 
Published: December 2011

Abstract
Behaviors that affect the distribution of fish within aquatic systems are important considerations in the design of sampling programs. Although movements consistent with reproductive homing have been documented for muskellunge Esox masquinongy in relatively large, complex systems, quantitative data describing their distribution at the restricted spatial scale relevant to small lake fisheries are lacking. We sampled muskellunge by means of fyke netting over 2 years in each of four Wisconsin lakes with surface areas between 110 and 588 ha. Individual capture locations were recorded. Each muskellunge sampled during the first year was injected with a passive integrated transponder to allow identification of the individuals recaptured during the second year. The number of recaptures with functional transponders during the second year ranged from 15 to 43 per lake. Capture site fidelity, defined as the percentage of recaptured fish being found in the same spawning area in two consecutive years, varied from 55% to 93%. The results are relevant to population estimation and broodstock collection for artificial propagation. Population estimates need to include all spawning habitats because marked and unmarked fish are not well mixed throughout the lake during the spawning season. Because repeated netting effort at the same locations among years is likely to resample individuals used for broodstock collection, netting effort should be dispersed among spawning sites.
Received October 21, 2010; accepted February 18, 2011
Impervious Surface, Summer Dissolved Oxygen, and Fish Distribution in Chesapeake Bay Subestuaries: Linking Watershed Development, Habitat Conditions, and Fisheries Management
Authors: Uphoff James H. , McGinty Margaret , Lukacovic Rudolph , Mowrer James , Pyle Bruce 
Published: December 2011

Abstract
We estimated target and limit impervious surface reference points (ISRPs) based on Chesapeake Bay dissolved oxygen (DO) criteria, and we examined associations and relationships among the percentage of watershed in impervious surface (IS), summer DO, and the presence of indicator species (blue crab Callinectes sapidus, white perch Morone americana, striped bass M. saxatilis, and spot Leiostomus xanthurus) in bottom waters of nine brackish subestuaries of Chesapeake Bay. Ideally, a target ISRP represented a level of development that maintained mean bottom DO at 5 mg/L or greater, while an ISRP threshold represented development that degraded mean bottom DO to less than 3 mg/L. The proportion of bottom trawls containing each indicator species rapidly declined from about 0.40 to 0.10 when DO fell below 3 mg/L, whereas the proportion remained at about 0.50 when DO was above 5 mg/L. The IS percentage had a significant negative influence on mean bottom DO and the odds that indicator species were present in midchannel bottom waters (0.8–7.0 m deep). Watersheds at or below a target IS of 5.5% (rural watershed) maintained mean bottom DO above 3 mg/L, but mean DO was only occasionally at or above 5 mg/L. Mean DO seldom exceeded 3 mg/L in watersheds with an IS value above 10% (suburban threshold). Comprehensive watershed management will be needed to offset significant degradation of bottom-water fish habitat in brackish subestuaries if rural lands are converted to suburban areas.
Received July 6, 2010; accepted March 23, 2011
A Comparison of Egg Funnel and Egg Bag Estimates of Egg Deposition in Grand Traverse Bay, Lake Michigan
Authors: Barton Nathan T. , Galarowicz Tracy L. , Claramunt Randall M. , Fitzsimons John D. 
Published: December 2011

Abstract
Reefs are used for spawning by Great Lakes fishes such as the lake trout Salvelinus namaycush, lake whitefish Coregonus clupeaformis, and cisco C. artedi. We designed egg funnels as a new type of sampling gear for quantifying egg deposition while minimizing losses of eggs to physical disturbance and predation. Egg funnels were compared with traditionally used egg bags to quantify egg deposition by spawning fish. In addition, the efficiencies of the egg funnels and egg bags were measured by seeding each gear type with artificial lake trout and lake whitefish eggs in situ. Egg funnels were as efficient as or more efficient than egg bags for capturing artificial eggs and naturally deposited lake trout eggs in both 2008 and 2009. Egg funnels had lower efficiency than egg bags for capture of natural coregonid eggs in 2008, potentially due to avoidance of the gear by spawners; gear avoidance was reduced by burying the egg funnels more deeply in 2009. Accurate estimates of egg deposition will assist fisheries managers in making more-informed decisions for management actions, such as stocking strategies and habitat protection.
Received November 29, 2010; accepted April 26, 2011
Evaluation of Offshore Stocking of Lake Trout in Lake Ontario
Authors: Lantry B. F. , O'Gorman R. , Strang T. G. , Lantry J. R. , Connerton M. J. , Schaner T. 
Published: December 2011

Abstract
Restoration stocking of hatchery-reared lake trout Salvelinus namaycush has occurred in Lake Ontario since 1973. In U.S. waters, fish stocked through 1990 survived well and built a large adult population. Survival of yearlings stocked from shore declined during 1990–1995, and adult numbers fell during 1998–2005. Offshore stocking of lake trout was initiated in the late 1990s in response to its successful mitigation of predation losses to double-crested cormorants Phalacrocorax auritus and the results of earlier studies that suggested it would enhance survival in some cases. The current study was designed to test the relative effectiveness of three stocking methods at a time when poststocking survival for lake trout was quite low and losses due to fish predators was a suspected factor. The stocking methods tested during 2000–2002 included May offshore, May onshore, and June onshore. Visual observations during nearshore stockings and hydroacoustic observations of offshore stockings indicated that release methods were not a direct cause of fish mortality. Experimental stockings were replicated for 3 years at one site in the southwest and for 2 years at one site in the southeast. Offshore releases used a landing craft to transport hatchery trucks from 3 to 6 km offshore out to 55–60-m-deep water. For the southwest site, offshore stocking significantly enhanced poststocking survival. Among the three methods, survival ratios were 1.74 : 1.00 : 1.02 (May offshore : May onshore : June onshore). Although not statistically significant owing to the small samples, the trends were similar for the southeast site, with survival ratios of 1.67 : 1.00 : 0.72. Consistent trends across years and sites indicated that offshore stocking of yearling lake trout during 2000–2002 provided nearly a twofold enhancement in survival; however, this increase does not appear to be great enough to achieve the 12-fold enhancement necessary to return population abundance to restoration targets.
Received November 29, 2010; accepted May 18, 2011