bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recreational Freshwater Angler Success Is Not Significantly Different from a Random Catch Model
Authors: Seekell David A. 
Published: December 2011

Abstract
Most fish are caught by a small number of anglers. This striking empirical regularity has been attributed to angler skill, equipment, food-web structure, and fisheries management. I use long-term angler log data from Montana and creel survey data from the lower Current River of Missouri to test the hypothesis that inequality in fish catch is consistent with random chance. Catch data for largemouth bass Micropterus salmoides and lake trout Salvelinus namaycush recorded in angler logs for six Montana lakes were highly unequal (Gini coefficients = 0.26–0.64) but not significantly different from the theoretical expectation that chance determines success. The catch data from the lower Current River creel survey were more unequal than the Montana angler log data (Gini coefficient = 0.71) but, again, not significantly different from the theoretical expectation that chance determines success. As the amount of time spent fishing increases, the mean catch increases and the shape of the probability distribution of obtaining a certain size catch changes from being positively skewed to being symmetrical. Effective tests of skill and other factors that might promote larger catches require better measures and appropriate data with which to evaluate alternative models.
Received September 8, 2010; accepted January 3, 2011
Retention of Passive Integrated Transponder Tags in Stream-Dwelling Rainbow Trout
Authors: Meyer Kevin A. , High Brett , Gastelecutto Nick , Mamer Elizabeth R. J. , Elle F. Steven 
Published: December 2011

Abstract
Passive integrated transponder (PIT) tags have been widely used as a tool for various monitoring and research needs, but the retention of PIT tags has rarely been tested in resident salmonids. We quantified the short-term (≤1 week), annual (1 year), and long-term (≥1 year) retention rates of PIT tags placed in the peritoneal cavity of small resident rainbow trout Oncorhynchus mykiss in 11 study streams and assessed whether fish size and gender affected tag retention. Short-term retention rates were at least 92% and averaged 96% for all streams, but a paired t-test nevertheless indicated that experienced taggers had significantly higher short-term retention rates (mean, 98%) than did inexperienced taggers (mean, 95%). Annual retention rates for PIT tags averaged 81% among all study streams, ranging from a low of 67% to a high of 92%. Annual retention rates were lower for larger rainbow trout than for their smaller counterparts. Long-term tag loss for females was the same as for males for fish smaller than 15 cm but significantly higher for fish 15 cm or more, suggesting that egg expulsion was the primary cause of tag loss.
Received August 27, 2010; accepted January 3, 2011
Radiotelemetry to Estimate Stream Life of Adult Chum Salmon in the McNeil River, Alaska
Authors: Peirce Joshua M. , Otis Edward O. , Wipfli Mark S. , Follmann Erich H. 
Published: December 2011

Abstract
Estimating salmon escapement is one of the fundamental steps in managing salmon populations. The area-under-the-curve (AUC) method is commonly used to convert periodic aerial survey counts into annual salmon escapement indices. The AUC requires obtaining accurate estimates of stream life (SL) for target species. Traditional methods for estimating SL (e.g., mark–recapture) are not feasible for many populations. Our objective in this study was to determine the average SL of chum salmon Oncorhynchus keta in the McNeil River, Alaska, through radiotelemetry. During the 2005 and 2006 runs, 155 chum salmon were fitted with mortality-indicating radio tags as they entered the McNeil River and tracked until they died. A combination of remote data loggers, aerial surveys, and foot surveys were used to determine the location of fish and provide an estimate of time of death. Higher predation resulted in tagged fish below McNeil Falls having a significantly shorter SL (12.6 d) than those above (21.9 d). The streamwide average SL (13.8 d) for chum salmon at the McNeil River was lower than the regionwide value (17.5 d) previously used to generate AUC indices of chum salmon escapement for the McNeil River. We conclude that radiotelemetry is an effective tool for estimating SL in rivers not well suited to other methods.
Received July 21, 2010; accepted January 9, 2011
Simulated Population Responses of Common Carp to Commercial Exploitation
Authors: Weber Michael J. , Hennen Matthew J. , Brown Michael L. 
Published: December 2011

Abstract
Common carp Cyprinus carpio is a widespread invasive species that can become highly abundant and have deleterious ecosystem effects. Thus, aquatic resource managers are interested in controlling common carp populations, but control is difficult, in part, because of the inherent uncertainty as to how populations respond to exploitation. To better understand this response, we evaluated the population dynamics (recruitment, growth, and mortality) of common carp in three natural lakes in eastern South Dakota. Common carp exhibited similar population dynamics across these three systems, which were characterized by consistent recruitment (ages 3–15 being present), fast growth (K = 0.37–0.59), and low mortality (A = 1–7%). We then modeled the effects of commercial exploitation on size structure, abundance, and egg production to determine its utility as a management tool to control populations. All three populations responded similarly to exploitation simulations in which a 575-mm length restriction represented commercial gear selectivity. Simulated common carp size structure declined modestly (9–37%) in all simulations. The abundance of common carp declined dramatically (28–56% of starting levels) at low levels of exploitation (0–20%), but exploitation greater than 40% had little additive effect, the final populations only being reduced 49–79% despite high exploitation (&gt;90%). At a moderate level of exploitation (40%), maximum lifetime egg production was reduced to 77–89% of starting levels, indicating the potential for recruitment overfishing. Exploitation further reduced common carp size structure, abundance, and egg production when simulations were not size selective. Our results provide insights into the ways in which common carp populations may respond to exploitation. Although commercial exploitation may be able to partially control populations, an integrated removal approach that removes all sizes of common carp has a greater chance of controlling population abundance and reducing the perturbations induced by this invasive species.
Received July 23, 2010; accepted January 6, 2011
Comparing Size, Movement, and Habitat Selection of Wild and Streamside-Reared Lake Sturgeon
Authors: Mann Kevin A. , Holtgren J. Marty , Auer Nancy A. , Ogren Stephanie A. 
Published: December 2011

Abstract
A streamside rearing facility (SRF) on the Big Manistee River, Michigan, was constructed for the purpose of rearing larval and age-0 lake sturgeon Acipenser fulvescens. Size, movement, and habitat selection were studied from 2007 to 2008 to determine whether there were differences between age-0 lake sturgeon reared in the streamside facility and natural cohorts. Lake sturgeon reared streamside showed no significant difference in length from their wild counterparts. Movement patterns were studied by attaching external radio transmitters to 17 age-0 streamside (198–250 mm total length) and 17 age-0 wild lake sturgeon (206–262 mm). The average weekly distances traveled by SRF fish ranged from 0.05–2.28 km (of 46 km surveyed) while wild fish traveled 0.04–2.81 km. In the river sections sampled, sand, pebble, and gravel comprised over 92.5% of the encountered substrates and Strauss index values indicated no differences in the presence of wild and SRF sturgeon over these substrates. Age-0 lake sturgeon were most often found in water 1.7 m deep with a velocity of 0.5 m/s, and no statistically significant differences were observed between wild and SRF sturgeon for either depth or velocity during the study years. By September, streamside-reared age-0 lake sturgeon attained a size similar to that of their wild cohorts and exhibited similar movement patterns and substrate association.
Received February 8, 2010; accepted January 27, 2011
Movements of Radio- and Acoustic-Tagged Adult Koi Carp in the Waikato River, New Zealand
Authors: Daniel Adam J. , Hicks Brendan J. , Ling Nicholas , David Bruno O. 
Published: December 2011

Abstract
The movement of koi, a highly colored variant of common carp Cyprinus carpio, was monitored for 18 months in the Waikato River, New Zealand, with both radiotelemetry and acoustic telemetry. Koi had large total linear ranges (mean, 39 km), and most fish (74%) monitored for more than 250 d traveled between the Waikato River and lateral habitat. Differences in total linear range and mean daily movement between years suggest a behavioral response associated with reduced habitat availability during periods of low flow. The movements of koi were highly variable and infrequent, suggesting that important long-range movements are missed in short-term studies (&lt;250 d), resulting in underestimations of total linear range. Our data suggest that large numbers of koi could have been intercepted traveling between lateral habitat and the Waikato River during 1 of 2 years, indicating that point source removal would be highly effective.
Received June 12, 2009; accepted January 20, 2011
Testing the Severity of Ill Effects Model for Predicting Fish Abundance and Condition
Authors: Smedley Rosalyn A. , Curry R. Allen , Gray Michelle A. 
Published: December 2011

Abstract
We tested the severity of ill effects (SEV) model as a predictor of the potential impacts of suspended sediment in small streams in an agricultural region of New Brunswick. Proposed by Newcombe and Jensen, the SEV uses the concentration of suspended sediment and the duration of exposure to predict the impacts on fish. In 2007, eight streams with brook trout Salvelinus fontinalis and slimy sculpin Cottus cognatus were used to test the SEV model. Total suspended solids measured from May to August were used to calculate the SEV index using two different methods. Our analyses indicated poor correlations between the SEV index and measures of fish densities and condition factor. A survey of an additional eight streams in the region over 2 years indicated that local habitat and landscape features and temperature were better predictors of fish density and species occurrence. These results demonstrate the complexity of interpreting stressor impacts and the challenges inherent in developing indices of stress for fish in natural streams.
Received January 20, 2010; accepted January 28, 2011
Characterization of Plasma Vitellogenin and Sex Hormone Concentrations during the Annual Reproductive Cycle of the Endangered Razorback Sucker
Authors: Hinck Jo Ellen , Papoulias Diana M. , Annis Mandy L. , Tillitt Donald E. , Marr Carrie , Denslow Nancy D. , Kroll Kevin J. , Nachtmann Jason 
Published: December 2011

Abstract
Population declines of the endangered razorback sucker Xyrauchen texanus in the Colorado River basin have been attributed to predation by and competition with nonnative fishes, habitat alteration, and dam construction. The reproductive health and seasonal variation of the reproductive end points of razorback sucker populations are currently unknown. Using nonlethal methods, we characterized the plasma hormonal fluctuations of reproductively mature female and male razorback suckers over a 12-month period in a hatchery by measuring their vitellogenin (VTG) and three sex hormones: 17β-estradiol (E2), testosterone (T), and 11-ketotestosterone (KT). Fish were identified as reproductive or nonreproductive based on their body weight, VTG, and sex hormone profiles. In reproductive females, the E2 concentration increased in the fall and winter, and increases in T and VTG concentrations were generally associated with the spawning period. Mean T concentrations were consistently greater in reproductive females than in nonreproductive females, but this pattern was even more pronounced during the spawning period (spring). Consistently low T concentrations (&lt;3 ng/mL) in adult females during the spawning period may indicate reproductive impairment. In reproductive males, spring increases in KT and T concentrations were associated with spawning; concentrations of E2 (&lt;0.48 ng/mL) and VTG (&lt;0.001 mg/mL) were low in males throughout the study. In addition, the E2 : KT ratio and T were the best metrics by which to distinguish female from male adult razorback suckers throughout the year. These metrics of reproductive health and condition may be particularly important to recovery efforts of razorback suckers given that the few remaining wild populations are located in a river where water quality and quantity issues are well documented. In addition to the size, age, and recruitment information currently considered in the recovery goals of this endangered species, reproductive end points could be included as recovery metrics with which to monitor seasonal trends and determine whether repatriated populations are cycling naturally.
Received September 24, 2010; accepted February 18, 2011
Natural Mortality in Relation to Age and Fishing Mortality on Walleyes in Escanaba Lake, Wisconsin, during 1956–2009
Authors: Hansen Michael J. , Fayram Andrew H. , Newman Steven P. 
Published: December 2011

Abstract
To evaluate the dynamics of fishing and natural mortality, we used a catch–age cohort analysis model of the population dynamics of walleye Sander vitreus in Escanaba Lake, Wisconsin, during 1956–2009. The catch–age model was based on angling catches at age from a compulsory creel census, abundance at age from mark–recapture studies, and recruitment at age 0 from mark–recapture studies. Harvest of age-3 and older (age-3+) walleyes averaged 12.5 fish/ha and varied 55% among years during 1956–2002, before the imposition of a 71-cm (28-in) minimum length limit that eliminated harvest. The population density of age-3+ walleyes averaged 34.8 fish/ha and varied 51% among years during 1956–2009. Annual exploitation of age-3+ walleyes averaged 34% during 1956–2002 and varied 35% among years during that period. The variation in population density explained only 0.5% of the variation in annual exploitation during 1956–2002. Natural mortality was best described by a model with decreasing age-specific vulnerability and a negative relationship with angling exploitation. Relative vulnerability to natural mortality declined gradually with age from 100% at age 0 to 83% at age 3, 50% at age 9.4, and 24% at age 17. Relative vulnerability to fishing mortality increased sharply from less than 1% at age 0 to 98% at age 3, peaked at 100% at age 4, and declined gradually to 66% at age 17. Fully vulnerable natural mortality (M) declined from 0.70 to 0.10 (mean = 0.41) as annual angling exploitation (u) on age-3+ walleyes increased from 0.0 to 0.65 (mean = 0.30). Our findings suggest that natural mortality declines with age and is inversely related to fishing mortality, so that it varies among ages and years. We conclude that stock assessment models for walleye fisheries should evaluate the effects of year-specific and age-specific natural mortality on model predictions.
Received September 4, 2010; accepted February 24, 2011
Efficiency of Gastric Lavage on Age-0 Brook Trout and the Influence on Growth and Survival
Authors: Hafs Andrew W. , Niles Jonathan M. , Hartman Kyle J. 
Published: December 2011

Abstract
Accurate knowledge of food webs is important in understanding aquatic ecology. One common way to determine the food web structure of an aquatic ecosystem is to perform stomach content analysis. Gastric lavage has developed into the preferred method for collecting dietary data from live fish. The objective of this study was to determine the efficiency of gastric lavage for age-0 brook trout Salvelinus fontinalis. Also, to assess the effects on short- and long-term growth and survival, age-0 brook trout were monitored for 2 months following the gastric lavage procedure. Gastric lavage was extremely efficient (&gt;97% of dry weight; &gt;98% by number) at removing Ephemeroptera, Plecoptera, and Trichoptera larvae fed live to age-0 brook trout larger than 50 mm total length (TL). Neither growth nor survival was significantly influenced by gastric lavage. Long-term survival was excellent (94%) and did not differ from that of control fish. Gastric lavage is thus an efficient, safe method for stomach content analysis of age-0 brook trout larger than 50 mm TL.
Received September 29, 2010; accepted March 16, 2011
Survival of Angled Saugers in the Lower Tennessee River
Authors: Kitterman Christy L. , Bettoli Phillip W. 
Published: December 2011

Abstract
An intense winter fishery for sauger Sander canadensis exists in the lower Tennessee River, and the objective of this study was to estimate the survival of angled saugers. In February 2008 and January–March 2009, 81 angled saugers (72 live plus 9 euthanized) were affixed with ultrasonic tags. The movements (or lack thereof) by saugers released alive were compared with those of euthanized fish to assess survival. Sixty-eight percent of the tagged saugers that were released alive exhibited maximum daily movements exceeding the greatest movement of any euthanized fish (0.5 km/d), and those fish were subsequently classified as survivors. The upstream movements of several euthanized fish indicated that their carcasses were ingested by piscivorous scavengers. In logistic models, the probability of mortality was significantly and inversely related to total length but not to capture depth, water temperature, handling time, or ascent rate. In 2 × 2 contingency tables, the fate of released saugers was not found to be associated with either the presence or absence of bleeding from the hooking wound or whether or not the fish displayed gastric distension. Most released fish survived despite the fact that gastric distension was observed in 72% of the angled saugers.
Received August 11, 2010; accepted April 21, 2011
Information Flow within the Social Network Structure of a Joint Strategic Plan for Management of Great Lakes Fisheries
Authors: Leonard Nancy J. , Taylor William W. , Goddard Chris I. , Frank Kenneth A. , Krause Ann E. , Schechter Michael G. 
Published: December 2011

Abstract
Transboundary fish stocks are governed by multiple entities, involving individuals with different expertise and sociocultural backgrounds and representing various institutions and jurisdictions. At times, individuals from these entities collaboratively make fishery governance decisions, and the existence of collegial or personal relationships may facilitate the decision-making process and result in better management of fish stocks. Although studies have assessed several aspects of fisheries institutional structures, very few have looked at the impact of social network structure. In this study, we found evidence for the perceived effectiveness of A Joint Strategic Plan for Management of Great Lakes Fisheries in its social network structure. We focused on the frequency of interactions for exchanging information about Great Lakes fish stocks in general and lake sturgeon Acipenser fulvescens in particular. These informational exchanges correspond to distinct social network structures, the fish stocks network and the lake sturgeon network. Similarities in participants’ attributes and perceptions about fisheries governance may have facilitated the formation of social ties within these networks. The lake sturgeon network had significant subgroups wherein flow was more concentrated. The formation of these subgroups appears to have been influenced by individuals’ employer type, committee affiliation, and perception about lake sturgeon governance. These subgroups were found to have 11 central individuals and two central subgroups. When comparing the central and noncentral individuals’ attributes and perceptions, we did not find a significant difference that explains why the 11 individuals were central. Similarly, no significant differences were found in comparing the central and noncentral subgroups. In assessing the flow of information within and across these subgroups, we found that it was evenly distributed with some specialization of flow between subgroups, the latter probably related to the presence of bridging individuals connecting the subgroups.
Received March 24, 2010; accepted March 23, 2011
Preliminary Evaluation of a Large-Scale American Eel Conservation Stocking Experiment
Authors: Pratt Thomas C. , Threader Ron W. 
Published: December 2011

Abstract
Significant declines in the recruitment of American eels Anguilla rostrata to formerly productive habitats in the upper St. Lawrence River and Lake Ontario resulted in the implementation of an experimental conservation stocking program. Nearly 3.8 million American eels (glass eel and elver stages) were stocked during 2006–2009. Our study objectives were to (1) assess the adequacy of sampling procedures for following temporal changes in stocked eel abundance, (2) examine captured eels for evidence of spinal trauma, (3) qualitatively evaluate whether stocked eels would disperse outside of stocking locations, and (4) provide initial data on biological variables describing young stocked yellow eels. Boat electrofishing was successful at capturing all four stocked year-classes, and the densities of stocked eels in the main stocking locations ranged from 25 to 275 eels/ha. Estimated sampling precision ranged from 0.15 to 0.28, and the estimated sample sizes required to detect a 50% change in stocked eel densities ranged from 27 to 112 electrofishing transects depending on location and season. The stocked American eels dispersed throughout Lake Ontario and demonstrated among the fastest recorded growth rates for this species: 60 to 123 mm/year. The first male American eels ever identified in the St. Lawrence River watershed were among the stocked individuals assessed for gender. We conclude that boat electrofishing for yellow American eels has the potential to measure stocking effectiveness along shallow shorelines with limited aquatic vegetation. We also recognize that the ultimate assessment of the conservation stocking experiment will not be made until future studies on the population demographics, migratory behavior, and spawning physiology of stocked American eels are complete.
Received December 10, 2010; accepted May 11, 2011