bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maximum Output of Peak Power for Two Backpack Electrofishers Operated at Various Pulsed Direct Current Duty Cycles and Water Conductivity Levels
Authors: Dean Jan C. , Temple Alan J. 
Published: December 2011

Abstract
The objectives of this research were to (1) determine the maximum output of peak power for two backpack electrofishers (Smith-Root Model LR-24; ETS Electrofishing Model ABP-3) at various pulsed DC (PDC) duty cycles and over a wide range of resistance levels and (2) use those results to develop a generalized model for predicting the maximum output of peak power available from backpack electrofishers for various water conductivity levels and duty cycles. The electrofishers were operated to maximum capacity under controlled conditions for water conductivities of 19, 155, and 610 μS/cm and for PDC duty cycles of 15, 25, and 50%. The results agreed closely with those expected based upon the manufacturer ratings for these backpack electrofishers and provided a graphical and analytical methodology for predicting backpack electrofisher capabilities over a range of water conductivity levels when operated at duty cycles recommended for electrofishing. Both electrofishers produced square wave PDC at low water conductivities. At higher water conductivities, the waveforms for both electrofishing units deviated from square pulses as they approached shutoff loading, but the response varied between electrofishers.
Received April 12, 2010; accepted February 9, 2011
Landscape Models of Brook Trout Abundance and Distribution in Lotic Habitat with Field Validation
Authors: McKenna James E. , Johnson James H. 
Published: December 2011

AbstractBrook trout Salvelinus fontinalis are native fish in decline owing to environmental changes. Predictions of their potential distribution and a better understanding of their relationship to habitat conditions would enhance the management and conservation of this valuable species. We used over 7,800 brook trout observations throughout New York State and georeferenced, multiscale landscape condition data to develop four regionally specific artificial neural network models to predict brook trout abundance in rivers and streams. Land cover data provided a general signature of human activity, but other habitat variables were resistant to anthropogenic changes (i.e., changing on a geological time scale). The resulting models predict the potential for any stream to support brook trout. The models were validated by holding 20% of the data out as a test set and by comparison with additional field collections from a variety of habitat types. The models performed well, explaining more than 90% of data variability. Errors were often associated with small spatial displacements of predicted values. When compared with the additional field collections (39 sites), 92% of the predictions were off by only a single class from the field‐observed abundances. Among “least‐disturbed” field collection sites, all predictions were correct or off by a single abundance class, except for one where brown trout Salmo trutta were present. Other degrading factors were evident at most sites where brook trout were absent or less abundant than predicted. The most important habitat variables included landscape slope, stream and drainage network sizes, water temperature, and extent of forest cover. Predicted brook trout abundances were applied to all New York streams, providing a synoptic map of the distribution of brook trout habitat potential. These fish models set benchmarks of best potential for streams to support brook trout under broad‐scale human influences and can assist with planning and identification of protection or rehabilitation sites.Received August 24, 2010; accepted March 1, 2011
Validation of Morphological Characteristics Used for Field Identification of Bull Trout × Brook Trout Hybrids
Authors: Popowich Ryan C. , Venturelli Paul A. , Stelfox Jim D. , Taylor Eric B. 
Published: December 2011

Abstract
Bull trout Salvelinus confluentus are of conservation concern throughout much of their range, in part because of displacement by and hybridization with nonnative brook trout S. fontinalis. Hybridization between these species can complicate efforts to control brook trout because hybrids are often difficult to distinguish from parental species. Here, we assess the reliability of five morphological characteristics that were used to identify bull trout × brook trout hybrids among 106 fish collected from Quirk Creek, Alberta. Genetic analysis of up to three microsatellite loci suggested that hybrids were correctly identified 95% of the time and that no bull trout were mistaken for hybrids. Visual inspection of photographs of hybrids suggested that dorsal fin markings were the most reliable morphological characteristic for identifying hybrids. Based on these results, we recommend that field identification of bull trout × brook trout hybrids be based solely on dorsal fin markings.
Received November 20, 2010; accepted March 21, 2011
Evaluating Two Observational Sampling Techniques for Determining the Distribution and Detection Probability of Age-0 Smallmouth Bass in Clear, Warmwater Streams
Authors: Brewer Shannon K. , Ellersieck Mark R. 
Published: December 2011

Abstract
Accurate determination of the distribution and abundance of age-0 sport fish, such as smallmouth bass Micropterus dolomieu, is an important aspect of successful species management (e.g., characterizing nursery habitats for protection or enhancement; identifying reproductive dynamics and influences of environmental variables). Two observational techniques—snorkeling and above-water (AW) observation—were evaluated in several Missouri Ozark streams to determine (1) accuracy of identifying age-0 smallmouth bass with each technique, (2) detection probabilities under a variety of channel unit (CU) conditions (i.e., discrete morphological features such as riffles or pools) and the relations between detection probability and hydraulic variables, and (3) behavioral responses (fright response, return response, or no response) of fish to the observers using each technique. Identification of age-0 smallmouth bass was over 90% accurate when using AW observation in shallow water and when snorkeling in deep water. In both streams, detection probabilities differed depending on the CU sampled and the method used. In deep pools, detection probabilities when snorkeling were two to three times those obtained from AW observation; however, AW observation was more efficient for sampling most shallow-water (&lt;0.5-m) CUs. Velocity had no significant relation to detection probability, whereas depth was significantly related to detection probability for both sampling methods (the relationship was positive for snorkeling and negative for AW observation). The percentage of age-0 smallmouth bass that exhibited a fright response was greatest for fish observed by snorkeling in shallow-water CUs. On average, approximately 20% of fish showed a fright response, but a large proportion of these fish exhibited a return response. Our results indicate that multiple sampling methods may be necessary to achieve high accuracy when sampling small fish in a variety of CUs, and snorkeling and AW observation may be viable methods for selecting CUs in many warmwater streams. Additional work is recommended to address knowledge gaps, especially those related to the influence of biotic and abiotic variables that were not measured in this study.
Received November 9, 2010; accepted May 12, 2011
Estimating the Hatchery Fraction of a Natural Population: A Bayesian Approach
Authors: Barber Jarrett J. , Gerow Kenneth G. , Connolly Patrick J. , Singh Sarabdeep 
Published: December 2011

Abstract
There is strong and growing interest in estimating the proportion of hatchery fish that are in a natural population (the hatchery fraction). In a sample of fish from the relevant population, some are observed to be marked, indicating their origin as hatchery fish. The observed proportion of marked fish is usually less than the actual hatchery fraction, since the observed proportion is determined by the proportion originally marked, differential survival (usually lower) of marked fish relative to unmarked hatchery fish, and rates of mark retention and detection. Bayesian methods can work well in a setting such as this, in which empirical data are limited but for which there may be considerable expert judgment regarding these values. We explored a Bayesian estimation of the hatchery fraction using Monte Carlo–Markov chain methods. Based on our findings, we created an interactive Excel tool to implement the algorithm, which we have made available for free.
Received March 30, 2011; accepted June 21, 2011
Largemouth Bass Nest Site Selection in Small, North Temperate Lakes Varying in Littoral Coarse Woody Habitat Abundances
Authors: Weis Jerome J. , Sass Greg G. 
Published: December 2011

Abstract
Coarse woody habitat (CWH) in the littoral zone is an important habitat feature in freshwater systems and has been suggested to influence nest density and nest site selection by black basses Micropterus spp. (e.g., largemouth bass M. salmoides and smallmouth bass M. dolomieu). To test for a relationship between nest site selection or nest density and the abundance of littoral CWH, we monitored largemouth bass nest site selection in the littoral zones of two small, northern Wisconsin lakes (comprising a total of three separated basins) for three consecutive spawning seasons. Our study sites varied in natural and manipulated abundances of CWH; spawning seasons before and after a whole-basin CWH reduction or a whole-basin CWH addition were examined. Within-basin analysis provided some evidence that local variation in CWH abundance influenced local nest density; however, this relationship was only significant for one basin in a single season. Among basins and across seasons, we observed a positive but nonsignificant effect of littoral CWH density on nest density and inconsistent responses to the CWH manipulations. Although littoral CWH is an important habitat feature influencing fish populations, communities, and life histories, our results suggest that CWH did not directly limit largemouth bass nest densities and was not a strong driver of nest site selection in these lakes. Nevertheless, policies allowing human-mediated removals of CWH from freshwater systems may still be detrimental to fish communities and other taxa that are dependent upon CWH.
Received March 31, 2011; accepted July 13, 2011
Population Dynamics of Lake Ontario Lake Trout during 1985–2007
Authors: Brenden Travis O. , Bence James R. , Lantry Brian F. , Lantry Jana R. , Schaner Ted 
Published: December 2011

Abstract
Lake trout Salvelinus namaycush were extirpated from Lake Ontario circa 1950 owing to commercial and recreational fishing, predation by sea lampreys Petromyzon marinus, and habitat degradation. Since the 1970s, substantial efforts have been devoted to reestablishing a self-sustaining population through stocking, sea lamprey control, and harvest reduction. Although a stocking-supported population has been established, only limited natural reproduction has been detected. Since the 1990s, surveys have indicated a continuing decline in overall abundance despite fairly static stocking levels. We constructed a statistical catch-at-age model to describe the dynamics of Lake Ontario lake trout from 1985 to 2007 and explore what factor(s) could be causing the declines in abundance. Model estimates indicated that abundance had declined by approximately 76% since 1985. The factor that appeared most responsible for this was an increase in age-1 natural mortality rates from approximately 0.9 to 2.5 between 1985 and 2002. The largest source of mortality for age-2 and older fish was sea lamprey predation, followed by natural and recreational fishing mortality. Exploitation was low, harvest levels being uncertain and categorized by length rather than age. Accurate predictions of fishery harvest and survey catch per unit effort were obtained despite low harvest levels by using atypical data (e.g., numbers stocked as an absolute measure of recruitment) and a flexible modeling approach. Flexible approaches such as this might allow similar assessments for a wide range of lightly exploited stocks. The mechanisms responsible for declining age-1 lake trout survival are unknown, but the declines were coincident with an increase in the proportion of stocked fish that were of the Seneca strain and a decrease in the overall stocking rate. It is possible that earlier studies suggesting that Seneca strain lake trout would be successful in Lake Ontario are no longer applicable given the large ecosystem changes that have occurred subsequent to invasion by dreissenid mussels.
Received January 19, 2011; accepted July 6, 2011
Using Lindgren–Pitman Hook Timers to Understand the Dynamics of Trotline Catches in a Large River
Authors: Steffensen Kirk D. , Eder Brandon L. , Pegg Mark A. 
Published: December 2011

Abstract
Trotlines have historically been used by commercial fishers to target ictalurids and have recently been shown to be effective for collecting sturgeons Scaphirhynchus spp. However, little is known about the gear–fish interaction after trotlines are deployed. Therefore, the objectives of this study were to determine whether trotlines equipped with Lindgren-Pitman (LP) hook timers could withstand harsh riverine conditions and whether catch rates, retention rates of hooked fish, capture times of targeted species, and bycatch would be affected. Our results showed no difference between standardized trotlines and trotlines with hook timers and indicated that 31% of pulled hook timers resulted in no fish being collected. Hook timers were activated by 69% of all the fish collected. The majority of fish collected were shovelnose sturgeon S. platorynchus (77%), of which 70% activated the timer. The fork length of the shovelnose sturgeon that did activate the timer (571.0 ± 60.1 mm [mean ± SE]) did not differ from that of fish that did not (542.4 mm). Overall, 43% of the hook timers were activated within the first 2 h of deployment and an additional 19% in the next 2-h period; 54% of the fish were collected prior to sunset. Our study shows that hook timers can be a valuable tool that will aid in the interpretation of trotline catches.
Received March 16, 2011; accepted June 14, 2011
Estimating Habitat-Specific Abundances of PIT-Tagged Juvenile Salmonids Using Mobile Antennas: A Comparison with Standard Electrofishing Techniques in a Small Stream
Authors: Sloat Matthew R. , Baker Peter F. , Ligon Franklin K. 
Published: December 2011

Abstract
The use of passive integrated transponder (PIT) tags in ecological studies is increasingly common, but evaluations of their performance and range of application in the field are still emerging. Here, we compare habitat unit–scale abundance estimates of PIT-tagged juvenile coho salmon Oncorhynchus kisutch and steelhead O. mykiss derived from multiple-pass surveys with a submersible pole-mounted PIT antenna and backpack electrofishing in a small coastal California stream. We found high concordance of methods for coho salmon and age-0 steelhead and moderate concordance for age-1 and older steelhead. Regression analysis of PIT antenna estimates on electrofishing estimates indicated an approximately one-to-one relationship between methods. Regression intercepts for coho salmon and age-0 steelhead were significantly greater than zero, but the differences were small (with an effect equivalent to less than one fish). We found no evidence that pool area, cover area, or cover complexity influenced the relationship between methods for coho salmon and age-0 steelhead, but some evidence that electrofishing may be more effective than PIT antennas for estimating the abundance of age-1 and older steelhead in pools with high cover complexity. Our results demonstrate that surveys using submersible PIT antennas can provide habitat unit–scale estimates of juvenile salmonid abundance similar to those derived from electrofishing in small streams. An advantage of using PIT antennas is that they allow fish abundance estimation without fish recapture and frequent sampling can occur without subjecting study animals to excessive handling stress or mortality. This is a particularly important consideration in studies of small populations, sensitive species, or fish listed under the U.S. Endangered Species Act.
Received July 30, 2010; accepted June 10, 2011
Applying Structured Decision Making to Recreational Fisheries Management
Authors: Irwin Brian J , Wilberg Michael J , Jones Michael L , Bence James R 
Published: December 2011

Abstract
Multiple objectives associated with recreational fishing, combined with multiple uncertainties, pose real challenges for management. We suggest that applying formal decision-making frameworks to partnership-based policy evaluations can prove beneficial to recreational fisheries management. We describe how a sequence of workshops can be used to engage scientists, managers, and other stakeholders and execute the steps of a structured decision-making process that centers on collaborative development of a quantitative forecasting model. This approach should aim to specify objectives and corresponding performance measures, identify critical uncertainties, and aid decision makers in making more informed choices among possible management options. An inclusive, participatory process can increase the transparency by which management decisions are made, provide an opportunity for tradeoffs to be discussed in a tangible way, and promote consensus building. Constructing and documenting a well-specified representation of the management process should also help reduce contention surrounding complex management decisions and promote proactive management.
Resumen
Toma Estructurada de Decisiones en el manejo de la pesca recreativa
Diversos objetivos relacionados con la pesca recreativa, combinados con múltiples incertidumbres, representan desafíos reales para el manejo. Se sugiere que al aplicar el enfoque de “toma formal de decisiones” a las evaluaciones de las políticas de participación, el manejo de la pesca recreativa puede beneficiarse. Se describe cómo una secuencia de talleres puede utilizarse tanto para concertar científicos, manejadores y otros participantes, así como también para llevar a cabo las etapas de un proceso estructurado de toma de decisiones, centrado en el desarrollo colaborativo de un modelo cuantitativo de predicción. Este enfoque debiera perseguir la postulación de objetivos precisos, el desarrollo de las correspondientes medidas de desempeño, identificación de las incertidumbres y asistencia a los administradores a tomar decisiones mejor informadas de entre diversas opciones de manejo. Un proceso incluyente y participativo puede incrementar la transparencia en las medidas de manejo, ofrece una oportunidad para que el espacio de negociación pueda discutirse de manera tangible y promueve el consenso. Crear y documentar una representación específica del proceso de manejo, también debiera ayudar a reducir los conflictos que rodean a las decisiones complejas de manejo y a promover un manejo proactivo.
Evolution of Catch Share Management: Lessons from Catch Share Management in the North Pacific
Authors: Fina Mark 
Published: December 2011

Abstract
Fishery managers, economists, industry advocates, and some environmental public interest groups are currently promoting catch shares (or the allocation of exclusive portions of the total allowable catch) as a means to address both environmental and economic fishery management problems. At the same time, a vocal opposition to catch share management has developed among some industry stakeholders, academics, and other public interest groups. Over the course of the last 20 years, while the debate has percolated, the North Pacific Fishery Management Council (known henceforth as the Council) has incrementally developed and overseen the implementation of five major catch share management programs for the fisheries it governs. This article draws on the experiences in the North Pacific fisheries to shed light on several facets of the debate over the efficacy of catch share management and suggests that catch share management is most effective and beneficial to stakeholders, when used in a measured manner, as part of a management program adapted specifically to a fishery and its stakeholders.
Red Snapper in the Gulf of Mexico and U.S. South Atlantic: Data, Doubt, and Debate
Authors: Cowan James H 
Published: December 2011

Abstract
Stock assessments provide fisheries managers with information that is used in the regulation of a fish stock. Assessments often rely upon a wide array of biological and fisheries data of varying quantity and quality, making the assessment process data hungry, complex, and uncertain. Assessment scientists face the difficulty of estimating numbers of individuals (among other biological benchmarks) of a population of widely distributed, often mobile, fishes for which direct measurement of almost everything is impossible. Consequently, stock assessment scientists are forced to use tools designed to assemble a variety of indirect measures into a statistical model capable of producing predictions to inform fisheries management about stock status and the consequences of past, current and future fishing practices. Despite large differences in estimates of the status of red snapper stocks in the Gulf of Mexico (U.S.) and south Atlantic Ocean (U.S.), and the management conclusions and decision drawn from these assessments, there are more similarities than differences in the basic data being used to inform assessment models, as well as in model outcomes concerning trends in biomass, catch-at-age and stock productivity. There are key differences in some of these data, and in how historical landings and uncertainty is handled in the assessment process, that result in large differences between the two management regions in beliefs about current and future productivity of red snapper stocks, and regulatory measures necessary for reaching management goals.
Eleven Ways to Improve Executive Management of Conflict
Authors: Fraidenburg Michael E 
Published: December 2011

Abstract
Conflict comes with the job of managing the public's natural resources. When I ask, fish and wildlife executives tell me they want employees with excellent conflict management skills. When I next ash what they are doing to prepare their employees to become skilled conflict managers, I regularly get a blank stare. Professionals are usually on their own to acquire these skills, largely through unguided, trial-and-error learning. Eleven actions leaders can take to improve conflict management in their organizations fall into four categories: Conflict prevention through training, adding a “conflict resolution” dimension to employee performance evaluations, maintaining an early warning system to detect emerging conflict, and creating robust stakeholder involvement processes.Contingency planning through systematically assessing vulnerabilities, conducting “What if…” strategy analyses, and maintaining a rapid response capacity for when a conflict emerges.Crisis management through ensuring that the organization can effectively analyze a conflict situation and can efficiently stabilize a bad situation so relationships can be rebuilt.Encouraging completed staff work by using a planning tool that teaches employees to bring a finished situation analysis and remedial plan forward at the same time they bring a conflict to the executive's attention.