bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resolving Some of the Complexity of a Mixed-Origin Walleye Population in the East Basin of Lake Erie Using a Mark–Recapture Study
Authors: Zhao Yingming , Einhouse Donald W. , MacDougall Thomas M. 
Published: December 2011

Abstract
At least two genetically distinct populations of walleye Sander vitreus reproduce in Lake Erie: one west-basin-origin population and one east-basin-origin population. Each year, some west-basin-origin walleyes migrate to the east basin and create a mixed-origin walleye population. Uncertainties associated with this migratory behavior make it difficult to describe the dynamics of the east-basin-origin population. We used mark–recapture analysis to estimate the dynamics of the east-basin-origin walleye population and to measure the contribution of west-basin-origin walleyes to the total walleye harvest in the east basin. Compared with the west-basin-origin walleyes, the east-basin-origin walleyes experienced lower fishing pressure, lower natural mortality, and a higher survival rate. On average, the west-basin-origin walleye migrants comprised about 90% of the annual harvest in the east basin. The number of the west-basin-origin walleyes migrating to the east basin was linearly related to their abundance. Walleyes showed a strong fidelity to their spawning sites. This study provided an approach to the assessment of population dynamics and the management of walleye fisheries in the east basin of Lake Erie.
Received June 7, 2010; accepted December 30, 2010
Physiological Effects of Potassium Chloride, Formalin, and Handling Stress on Bonytail
Authors: Sykes Catherine L. , Caldwell Colleen A. , Gould William R. 
Published: December 2011

Abstract
We characterized the sublethal physiological changes in bonytail Gila elegans subjected to consecutive 750-mg/L potassium chloride (KCl) and 25-mg/L formalin treatments for the removal of zebra mussel Dreissena polymorpha and quagga mussel D. bugensis veligers. Plasma cortisol, glucose, and osmolality were measured over 24 h and at 14 d posthandling after exposing bonytail to KCl and one net stressor (capture with a net), KCl plus formalin and two net stressors, and one or two net stressors without chemicals. Elevated plasma cortisol (322–440 ng/mL) and glucose (254–399 mg/dL) concentrations were observed in all treatments compared with the concentrations in control fish (plasma cortisol, 56 ng/mL; glucose, 43 mg/dL). While there were no detectable differences in plasma osmolality among the treatment and control fish, a difference was observed between fish that were handled once versus twice. Chemical effects of stress were not observed in any of the physiological responses when the KCl treatment was compared with the one-net stressor treatment or when the KCl plus formalin treatment was compared with the two-net stressor treatment. Cumulative responses, however, were observed between one net stressor and two net stressors for plasma glucose and osmolality but not for plasma cortisol. Plasma cortisol and glucose levels remained elevated at 24 h posthandling, indicating that bonytail had not completely recovered from the handling stressors and would benefit from a recovery period in protected refugia before being released.
Received August 23, 2010; accepted January 20, 2011
Evaluating Benchmarks of Population Status for Pacific Salmon
Authors: Holt Carrie A. , Bradford Michael J. 
Published: December 2011

Abstract
Canada is developing an indicator approach for assessing the biological status of conservation units of Pacific salmon Oncorhynchus spp. under its Wild Salmon Policy that is based, in part, on the abundance of adult fish. Two benchmarks will be used to place populations in one of three abundance categories. The lower benchmark is proposed to be at a level that allows for a substantial buffer between it and the abundance that would result in a population's being assessed as at risk of extirpation based on quantitative criteria used by the Committee on the Status of Endangered Wildlife in Canada. Using Monte Carlo simulation, we evaluated eight candidate lower benchmarks calculated from parameters of the stock–recruit relationship against two criteria, the probability of extirpation over 100 years and the probability of recovery to spawner abundances that result in the maximum sustainable yield in one or three generations. For modeled populations of moderate size (unfished equilibrium abundances &gt;25,000) and moderate productivity (∼four adult recruits produced per spawner at low spawner abundances), all benchmarks protected populations from extirpation when harvest restrictions were imposed at the lower benchmark. For small or unproductive populations, none of the benchmarks was adequate to prevent populations from being at risk of extirpation. However, those benchmarks that covaried with the productivity parameter of the stock–recruitment relationship performed better and are preferred to those that were derived mainly from estimates of habitat capacity.
Received May 31, 2010; accepted February 4, 2011
Balancing Biological Sustainability with the Economic Needs of Alaska's Sockeye Salmon Fisheries
Authors: Steiner Erin M. , Criddle Keith R. , Adkison Milo D. 
Published: December 2011

Abstract
Total revenue in the Bristol Bay, Alaska, fishery for sockeye salmon Oncorhynchus nerka has declined by 80% over the past two decades. In contrast to other fisheries where declining revenues are a consequence of declining catches, Bristol Bay sockeye salmon landings have remained high and the revenue decline is a result of falling prices, which in turn are a consequence of competition from increased production of rainbow trout/steelhead O. mykiss (hereafter, rainbow trout) and coho salmon O. kisutch farmed in Chile. This paper explores possible changes to current management strategies that would continue to ensure biological sustainability while enhancing economic returns. We simulate three management strategies for Bristol Bay sockeye salmon: fixed escapement range, conditional fixed harvest, and conditional fixed harvest rate. Yields from these simulations are combined with a forecast of Chilean rainbow trout and coho salmon production and a model of international trade flows for Alaskan sockeye salmon and Chilean coho salmon and rainbow trout to generate forecasts of exvessel price and total revenue for 2010 under each management strategy. The simulations suggest that a change from the current fixed escapement range management strategy could improve the economic health of the fishery without compromising biological sustainability.
Received March 2, 2010; accepted February 10, 2011
Dungeness Crab Mortality Due to Lost Traps and a Cost–Benefit Analysis of Trap Removal in Washington State Waters of the Salish Sea
Authors: Antonelis Kyle , Huppert Daniel , Velasquez Don , June Jeffrey 
Published: December 2011

Abstract
Loss of Dungeness crabs Cancer magister in derelict crab traps was estimated from catches and mortality in 24 simulated lost traps at two locations in Washington State. Equal numbers of recreational and commercial crab traps were initially baited and monitored weekly by divers until the bait was consumed and were monitored biweekly thereafter for 1 year. Dungeness crabs caught in the traps were individually tagged. Catch, escapement, retained catch, and mortality rates were estimated. The traps caught 1,077 Dungeness crabs, of which 500 (46%) died and 421 (39%) escaped. Mortality of sublegal males and females was expressed in legal male equivalents. The overall retained catch of Dungeness crabs (caught minus escaped) was 0.082 crabs·trap−1·d−1. After an initial lag, the cumulative daily mortality rate of Dungeness crabs rose steadily to 0.058 crabs·trap−1·d−1. An estimated 12,193 traps are lost annually in Washington waters of the Salish Sea, and the estimated trap fishing duration was 126 d for traps with escape cord (i.e., reflecting decomposition of the cord) and 2.2 years for traps without escape cord. Annual Dungeness crab loss was estimated at 178,874 legal male equivalents, translating to an exvessel value of US$744,296, or 4.5% of the value of recent harvests. Average annual net value to fishers from the saved Dungeness crabs (i.e., crabs available for harvest if lost traps had been removed) was estimated at $450,657–744,296 depending upon variable costs to harvest all of the saved crabs. Estimated net exvessel value of saved crabs ranged from $36.96 to $61.04 per removed trap compared with removal costs of $92.66–193.00 per trap. Removal of lost traps may be warranted in high-density fishing areas and for ecological reasons. Reducing the diameter of the escape cord and modifying the trap design could significantly reduce Dungeness crab mortality due to lost traps.
Received May 14, 2010; accepted February 10, 2011
Spawning Habitat Selection of Hickory Shad
Authors: Harris Julianne E. , Hightower Joseph E. 
Published: December 2011

Abstract
We examined the spawning habitat selectivity of hickory shad Alosa mediocris, an anadromous species on the Atlantic coast of North America. Using plankton tows and artificial substrates (spawning pads), we collected hickory shad eggs in the Roanoke River, North Carolina, to identify spawning timing, temperature, and microhabitat use. Hickory shad eggs were collected by both sampling gears in March and April. The results from this and three other studies in North Carolina indicate that spawning peaks at water temperatures between 12.0°C and 14.9°C and that approximately 90% occurs between 11.0°C and 18.9°C. Hickory shad eggs were collected in run and riffle habitats. Water velocity and substrate were significantly different at spawning pads with eggs than at those without eggs, suggesting that these are important microhabitat factors for spawning. Hickory shad eggs were usually collected in velocities of at least 0.1 m/s and on all substrates except those dominated by silt. Eggs were most abundant on gravel, cobble, and boulder substrates. Hickory shad spawned further upstream in years when water discharge rates at Roanoke Rapids were approximately average during March and April (2005 and 2007), as compared with a severe drought year (2006), suggesting that water flows may affect not only spawning site selection but also the quantity and quality of spawning habitat available at a macrohabitat scale. Using our field data and a Bayesian approach to resource selection analysis, we developed a preliminary habitat suitability model for hickory shad. This Bayesian approach provides an objective framework for updating the model as future studies of hickory shad spawning habitat are conducted.
Received July 16, 2010; accepted February 21, 2011
An Approach to Defining Stock Complexes for U.S. West Coast Groundfishes Using Vulnerabilities and Ecological Distributions
Authors: Cope Jason M. , DeVore John , Dick E. J. , Ames Kelly , Budrick John , Erickson Daniel L. , Grebel Joanna , Hanshew Gretchen , Jones Robert , Mattes Lynn , Niles Corey , Williams Sarah 
Published: December 2011

Abstract
The Magnuson–Stevens Fishery Conservation and Management Act (MSA) requires active management of all stocks at risk of overfishing or otherwise in need of conservation and management. In the Pacific Fishery Management Council groundfish fishery management plan, about two-thirds of the more than 90 managed stocks are currently without traditional assessments to help define stock status in relation to management targets. Stock complexes are often employed for management purposes in such situations. The guidelines issued in response to the 2006 MSA amendments defined a complex as a group of stocks with similar geographic distributions, life histories, and vulnerabilities to fisheries. This work uses productivity–susceptibility analysis (PSA) to measure the vulnerabilities of 90 managed groundfish stocks, 64 of which are currently managed within stock complexes. These stock complexes are reevaluated by first using a partitioning cluster analysis to group the stocks by depth and latitude. Vulnerability reference points are then established based on the PSA results to determine vulnerability groups of low, medium, high, and major concern within each ecological group. This method is a simple and flexible approach to incorporating vulnerability measures into stock complex designations while providing information with which to prioritize stock- and complex-specific management.
Received September 28, 2010; accepted February 23, 2011
Gender- and Year-Specific Mortality of Yellow Perch with Evidence of Compensatory Mortality
Authors: Schoenebeck Casey W. , Brown Michael L. 
Published: December 2011

Abstract
Gender- and year-specific survival (S) of yellow perch Perca flavescens, the tag recovery rate (f, i.e., the joint probability of a fish being harvested, the tag being recognized, and the tag being reported, corrected for tag loss and tagging mortality), and natural mortality (v) were estimated using Brownie tag recovery models. These models were constructed from 4 years of tagging and angler tag recovery data to determine whether mortality is additive or compensatory for the high- and low-quality yellow perch fishery types commonly found in eastern South Dakota glacial lakes. Natural mortality comprised the majority of total annual mortality, S was constant among years, and f was female-biased for both study populations. Survival and f did not vary among years for the low-quality population, providing inconclusive evidence of mortality function. However, a constant S coupled with annual changes in f and v (i.e., when harvest mortality increased, natural mortality decreased) suggests that mortality was compensatory for the high-quality population.
Received October 13, 2010; accepted March 3, 2011
Success or Failure? Do Indicator Selection and Reference Setting Influence River Rehabilitation Outcome?
Authors: Weber Christine , Peter Armin 
Published: December 2011

Abstract
Recovery indicators play a crucial role in the evaluation of river rehabilitation projects. Various types of biological indicators are used to address different ecosystem attributes (structure, composition, and function) at different levels of the biological hierarchy (population, guild, and community). Indicator values are evaluated against reference information from various sources, representing the conditions to be achieved (near-natural references) or to avoid (degraded references). We studied the extent to which investigators’ conclusions on project outcome were influenced by the indicator and reference types used. We analyzed 40 selected studies dealing with the recovery of riverine fish assemblages after active rehabilitation of physical habitat and lateral connectivity. In 32 (80%) of the 40 studies, fish response was measured at the population level. Structural and compositional indicators dominated (31 and 24 studies, respectively), while functional indicators were underrepresented (5 studies). Eighteen studies used multiple indicator types for a given ecosystem attribute, a given hierarchical level, or both. Among these studies, we found only very limited evidence that project outcome differed among different indicator types (1 study). In contrast, highly heterogeneous results were found within the different indicator types at the level of the individual study (i.e., indicators addressing the same hierarchical level and ecosystem attribute resulted in different evaluations of project outcome). Such heterogeneity was related to the spatiotemporal variability of the results and species-specific responses to physical habitat rehabilitation. Most studies (73%; 29 studies) used a single type of reference, and the majority focused on degraded conditions. Among the 10 studies that applied multiple reference types, one-third (3 studies) showed inconsistent results (i.e., one reference comparison produced a positive assessment for a given indicator, whereas the second comparison indicated that the endpoint was not achieved). We discuss the implications of inconsistent project outcomes for future monitoring activities.
Received July 6, 2010; accepted March 7, 2011
Freshwater Survival of Stranded Steelhead Kelts in Coastal Central California Streams
Authors: Barnett Lewis A. K. , Spence Brian C. 
Published: December 2011

Abstract
During 2008, spring drought conditions in the Santa Cruz Mountains of California resulted in hundreds of postspawn adult steelhead Oncorhynchus mykiss becoming stranded in streams and unable to return to sea. These individuals had no other option than to spend the entire summer and fall in freshwater habitats. As the fate of stranded kelts is poorly documented, we attempted to estimate the oversummer survival of steelhead kelts and to assess whether local habitat characteristics influenced survival rates. We found that nearly 40% of kelts observed during summer surveys were still alive in late October, just before the first significant rains of the season, and most individuals were observed to be in fair condition. Survival was higher for fish that resided in pools with substantial cover than for fish that occupied pools with only partial or no concealment. Overall, the unexpectedly high survival rates of stranded kelts suggest that the rescue and relocation of stranded steelhead to other habitats or to hatcheries may only be warranted when there are clear imminent threats to survival. Managers should consider the effects of strandings on population viability given that climate change may increase the frequency of strandings and decrease the survival of stranded individuals.
Received September 28, 2010; accepted April 28, 2011
Comparison of Retention Success for Multiple Tag Types in Common Snook
Authors: Boucek Ross E. , Adams Aaron J. 
Published: December 2011

Abstract
Tags are commonly used to uniquely identify fish in order to estimate population size, harvest rates, and fish behavior. However, some tags have the propensity to be shed (lost), which can bias results. To examine the shedding rates of external tags and the potential bias this introduces for common snook Centropomus undecimalis we marked adult snook with an internal 23-mm half duplex passive integrated transponder (PIT) tag (as a permanent mark) and one of two external tags: a T-bar anchor tag (44 mm; Floy, FD-68B) or a dart tag (89 mm × 2 mm; Floy, FT-1-94). Fish were tagged along sandy beaches of the Gulf of Mexico in southwestern Florida during the spawning season in 2007–2009. Short-term (37-d) external tag retention success was 100% for both tags. However, long-term (391-d) retention success was low for external tags (T-bar = 76%; dart = 38%). Given the limitations of and trade-offs among tag types, choosing the most appropriate tag will continue to challenge researchers. Until more universal tags are developed, researchers must carefully consider the advantages and disadvantages of each tag type with respect to different project objectives.
Received October 17, 2010; accepted May 19, 2011
Genetic Variation of Gray Triggerfish in U.S. Waters of the Gulf of Mexico and Western Atlantic Ocean as Inferred from Mitochondrial DNA Sequences
Authors: Antoni Luca , Emerick Nicholas , Saillant Eric 
Published: December 2011

Abstract
Gray triggerfish Balistes capriscus is a reef fish exploited by recreational and commercial fisheries in the southeastern United States. Recent stock assessments indicated that the species is overfished, and a rebuilding plan is in progress. The U.S. fishery is currently managed as a single stock owing to the absence of reliable information on stock structure. We sequenced a 617-base-pair fragment of the ND4 mitochondrial gene in a total of 150 specimens from five localities (South Texas, Louisiana, West Florida, southeastern Florida, and South Carolina) encompassing the exploited range of the species in the USA. Analysis of molecular variance, spatial analysis of molecular variance, and spatial autocorrelation analysis did not reveal significant spatial heterogeneity in haplotype distributions within the studied range. Significant departure from neutrality was inferred from neutrality tests and may reflect the signature of a rapid population expansion following the recent glacial epochs, an inference that was supported by the results of Bayesian coalescent analysis. While the present results are consistent with management of the species as a single stock, development of additional genetic markers is needed to increase the resolution in genetic analyses and evaluate fine-scale genetic stock structure in the region.
Received January 10, 2011; accepted May 5, 2011
Effect of Passive Integrated Transponder Tag Implantation Site on Tag Retention, Growth, and Survival of Two Sizes of Juvenile Bluegills and Yellow Perch
Authors: Kaemingk Mark A. , Weber Michael J. , McKenna Paul R. , Brown Michael L. 
Published: December 2011

Abstract
Passive integrated transponder (PIT) tags are commonly used to monitor growth, habitat use, activity rates, and survival of individual fish. However, for successful completion of research objectives, the tags must be retained and must not affect fish growth or survival. We compared the effects of PIT tagging location on tag retention, growth, and survival of juvenile bluegills Lepomis macrochirus and yellow perch Perca flavescens. In total, 80 bluegills and 80 yellow perch from two size-classes (75–101 and 128–162 mm total length) were randomly assigned to a control or to one of three tagging location treatments: isthmus, body cavity, or dorsal musculature. Fish received daily ad libitum rations and were monitored for survival. On days 14, 28, and 42, the fish were measured, weighed, and checked for tag retention. Use of the isthmus as a tagging location resulted in lower tag retention for both species and both size-classes relative to the body cavity and dorsal musculature locations. Tagging location had no detectable effect on growth or survival responses for either species or either size-class. Thus, PIT tags that are implanted in the dorsal musculature of large juvenile bluegills and yellow perch and in the body cavity of small juvenile bluegills and yellow perch can have high retention with minimal adverse effects.
Received May 4, 2011; accepted June 2, 2011
Mortality of Walleyes Angled from the Deep Waters of Rainy Lake, Minnesota
Authors: Talmage Philip J. , Staples David F. 
Published: December 2011

Abstract
Existing models of hooking mortality for walleyes Sander vitreus in large polymictic lakes are inadequate for estimating the number of catch-and-release mortalities in deeper, stratified lakes where fish are predominantly caught from depths greater than 10 m. To improve the understanding of how water depth affects catch-and-release mortality, logistic regression was used to investigate how depth of capture, fish length, and epilimnetic water temperature affect hooking mortality rates. In 2006 and 2007, 319 walleyes were caught by anglers at 5.8–17.1-m depths during a total of 10 angling events (July–September) on Rainy Lake, Minnesota. Fish were released into holding cages that allowed them the opportunity to reestablish themselves at their depths of capture; survival was recorded after 5 d (2 d for one cage). After accounting for the effects of experimental handling time (i.e., the time between hook removal and fish placement in the holding cage), capture depth had the largest effect on mortality; increases in either factor were associated with higher mortality rates. A mixed-effects model showed that pseudoreplication (i.e., correlations in survival rates among fish held in the same cage) did not detrimentally affect model parameter estimates or significance tests. In contrast to previous studies of hooking mortality in Minnesota, neither water temperature nor fish length best explained the mortality rates. By providing improvements over previous models, the logistic hooking mortality model developed in this study will allow managers to more effectively estimate hooking mortality rates in Rainy Lake and other deep lakes.
Received February 11, 2011; accepted May 13, 2011