bluuebunny/crossref_metadata_2025_split huggingface dataset:
Overwinter Growth and Mortality of Young-of-the-Year Windowpanes: Cohort-specific Responses
Authors: Neuman Melissa J. , Able Kenneth W. 
Published: October 2009

Abstract
We tested the overwintering capability of young-of-the-year (age-0) windowpanes Scophthalmus aquosus to determine if there are cohort-specific differences in growth and mortality. We conducted a laboratory study at ambient estuarine winter temperatures from 9 November 1995 to 22 April 1996 with two cohorts (spring-spawned cohort: 83–140 mm total length [TL]; fall-spawned cohort: 15–37 mm TL). We hypothesized that (1) among individuals within both cohorts, winter growth rates would be low compared with summer growth rates; and (2) overwinter mortality rates of the smaller, fall-spawned fish would be higher than those of larger, spring-spawned fish due to size-selective mortality. Under ambient winter temperatures (−2.0 to 14.0°C) with daily, ad libitum feeding in the laboratory, growth rates were low but positive for the fall- and spring-spawned fish. Overwinter mortality occurred in both cohorts but was higher for the fall cohort than for the spring cohort (75% and 31%, respectively). Within the fall cohort, mortality was size selective, with reduced survival of individuals smaller than 24 mm TL. Within the spring cohort, there was no evidence of size-selective mortality. We concluded that the first winter of life may be an important mortality bottleneck for both cohorts of age-0 windowpanes in the Middle Atlantic Bight but that mortality patterns are cohort specific and may be determined by different combinations of factors, such as fish size at the start of winter, the magnitude of water temperature decline between fall and winter, and the frequency and duration of extremely cold water temperatures. Thus, overwinter mortality during the first winter of life may influence the population dynamics of the windowpane and other multimodal spawners inhabiting the Middle Atlantic Bight.
Description and Initial Evaluation of a Text Message Based Reporting Method for Marine Recreational Anglers
Authors: Baker M. Scott , Oeschger Ian 
Published: October 2009

Abstract
Despite the large number of marine recreational anglers in the United States, there exist few opportunities for individuals to contribute self-reported effort and catch data directly to fisheries managers. Successfully implemented data collection programs based on self-reported information have been able to provide scientists with additional indices for comparisons with existing fisheries data sets and to increase angler participation and confidence in the fisheries management process. Limitations to self-reported data aside, the lack of a portable, electronic reporting device for the average angler has hindered development of new survey methods. We have developed a simple but fully customizable reporting method by which users can submit basic effort and catch information to an online database via text messages from mobile phones. To evaluate this new approach, we asked captains on behalf of six marine for-hire operations to send a text message to document effort, catch, and disposition of catch by species at the completion of each for-hire trip. Report submission was facilitated by RECTEXT, a compact syntax we developed to allow users to submit information within the technical limitations of a 160-character text message framework. During the course of the 4.5-month evaluation, participants submitted 128 trip-level reports that described 1,957 finfish interactions. Results and feedback from participants indicate that the approach is easy to use, is cost efficient, and allows for real-time reporting of information directly to an online database. In addition to the electronic angler diary application described here, we suggest that future evaluations of this approach be applied to tournament data collection, as the real-time nature of reporting and the organized structure of tournaments may provide a mechanism to both interact with all registered anglers and facilitate design of an unbiased sampling protocol for validating the self-reported data.
Virulence Variation of White Spot Syndrome Virus in Pacific White Shrimp Litopenaeus vannamei
Authors: Laramore S. E. , Scarpa J. , Laramore C. R. , Lin J. 
Published: October 2009

Abstract
The virulence of seven geographic isolates of white spot syndrome virus (WSSV; genus Whispovirus; China (strain CH1995), Nicaragua (strain N2000), Honduras (strain H2000), Ecuador (strains E-L1999 and E-LT2002), and Mexico (strains M-M2001 and M-LP2001)) was compared using a series of challenge experiments, each lasting 10 d. For each isolate, four quantified dilutions (10−6, 10−7, 10−8, and 10−9) of a viral inoculum were prepared from WSSV-infected shrimp tissue. Each viral inoculum was injected into 10 specific pathogen-free juvenile Pacific white shrimp Litopenaeus vannamei (0.25–1.50 g); controls received injections of marine crustacean physiological saline (3.2%). The minimum dose of viral inoculum that killed 50% of injected shrimp (LD50) was calculated for dilution, tissue concentration, and viral DNA amount. The CH1995 and M-M2001 isolates were the least virulent, with LD50 values of 10−6 to 10−7 of viral inoculum. The isolates could be grouped into three virulence clusters (CH1995 and M-M2001; N2000 and E-LT2002; and H2000, E-L1999, and M-LP2001). Virulence clusters were not altered by LD50 values based on viral DNA concentration, although a slight shifting of order in regards to virulence was seen among the three most virulent isolates (E-L1999, H2000, and M-LP2001). Overall, results indicate that there is a measurable virulence difference among WSSV isolates, which may correspond to geographical region.
Tumors in Brown Bullheads in the Chesapeake Bay Watershed: Analysis of Survey Data from 1992 through 2006
Authors: Pinkney Alfred E. , Harshbarger John C. , Rutter Michael A. 
Published: October 2009

Abstract
Liver and skin tumor prevalences in brown bullheads Ameiurus nebulosus have been used in the North American Great Lakes to designate highly contaminated areas of concern and monitor their recovery. Here we interpret the results of six surveys conducted in the Chesapeake Bay watershed between 1992 and 2006, with data for 647 fish. The objective has been to develop an adequate database to critically evaluate the use of tumor prevalence as a habitat quality indicator within the watershed. Surveys featured randomized fish collection; recording of sex, length, weight, and age; and histopathology of all livers and all raised skin lesions. The Bayes information criterion was used to analyze all possible combinations of age, gender, length, and weight as covariates for logistic regression. Length and gender were the covariates that best described liver tumor prevalence. There were no covariates in the model for skin tumor prevalence. In some surveys, biomarkers, such as biliary polynuclear aromatic hydrocarbon (PAH)-like metabolites, hepatic cytochrome P450 activity, and hepatic DNA adducts, were used with sediment and tissue chemistry data to evaluate classes of chemicals as likely contributors to tumor prevalence. We highlight two surveys of the Anacostia River, Washington, D.C. (average = 55% liver tumors, 23% skin tumors), where sediment PAHs, biliary PAH-like metabolites, and hepatic DNA adducts were high, suggesting that PAHs play a major role. We show that logistic regression is an appropriate procedure for comparing “contaminated” versus “reference” locations, and we evaluate the utility of tumor surveys as an environmental indicator for the Chesapeake Bay watershed.
Are All Koi Ulcer Cases Associated with Infection by Atypical Aeromonas salmonicida? Polymerase Chain Reaction Assays of Koi Carp Skin Swabs Submitted by Hobbyists
Authors: Goodwin Andrew E. , Merry Gwenn E. 
Published: October 2009

Abstract
Infection by atypical Aeromonas salmonicida is regarded as the cause of ulcer disease (KUD) in koi carp Cyprinus carpio and goldfish Carassius auratus. However, other causes—including parasites, viral infection, and fungi—have been proposed. In our diagnostic work, we often fail to isolate A. salmonicida even when clear clinical signs of KUD are present. This failure may be because these fastidious and slow-growing bacteria are difficult to isolate in culture or because the bacteria are not actually present in the lesions. In this study, we used polymerase chain reaction (PCR) to detect A. salmonicida in DNA samples swabbed from koi carp ulcers. These alcohol-preserved samples were collected and submitted by hobbyists and included 40 separate cases from 12 different states. We identified atypical A. salmonicida by PCR in 52 of 62 samples submitted and in 33 of 40 unique cases. The negative findings for A. salmonicida by PCR could all be attributed to high water temperatures, prior antibiotic use, poor sample quality, or misdiagnosis of columnaris disease as KUD. Tests for Aphanomyces invadans by PCR were negative in every case. This work confirms that A. salmonicda is still the predominant cause of KUD and that our negative culture results were ost likely due to technical failures rather than an absence of A. salmonicda in the ulcer lesions.
A Comparison of Two Methodologies for Estimating Brook Trout Catch and Harvest Rates using Incomplete and Complete Fishing Trips
Authors: Keefe Donald G. , Perry Robert C. , Luther J. Glenn 
Published: October 2009

Abstract
On the island portion of Newfoundland and Labrador, Canada, the provincial government relies on roving creel surveys to assess the fishery for brook trout Salvelinus fontinalis. The estimation of catch and harvest rates for these surveys requires on-site interview methods that gather information from incomplete fishing trips. When the objective is to determine total catch, the mean-of-ratios estimator is the accepted method for deriving catch rate from incomplete trips, whereas the ratio-of-means estimator is the accepted method for deriving catch rate for completed trips. When we compared the two estimators using incomplete and complete trip catch data measured from the same sample of anglers, we found a persistent bias. Catch and harvest rates derived from the mean-of-ratios estimator were significantly higher than those obtained with the ratio-of-means estimator. Catch rate was higher by 32%, while harvest rate was higher by 39%. When we only used the completed trip data set for both calculations, we found a mean difference of 19% between the two estimators. We also found a second source of error. When we examined individual angler responses for catch and harvest, the estimates revealed a positive bias whereby the incomplete trips showed higher estimates relative to the complete trips (16% and 21%, respectively). These biases appear to be related to the estimation procedure as well as fish and fisher behavior at the individual angler level. We use linear regression analysis to help correct the bias associated with the mean-of-ratios estimator.
Defining and Characterizing Coolwater Streams and Their Fish Assemblages in Michigan and Wisconsin, USA
Authors: Lyons John , Zorn Troy , Stewart Jana , Seelbach Paul , Wehrly Kevin , Wang Lizhu 
Published: October 2009

Abstract
Coolwater streams, which are intermediate in character between coldwater “trout” streams and more diverse warmwater streams, occur widely in temperate regions but are poorly understood. We used modeled water temperature data and fish assemblage samples from 371 stream sites in Michigan and Wisconsin to define, describe, and map coolwater streams and their fish assemblages. We defined coolwater streams as ones having summer water temperatures suitable for both coldwater and warmwater species and used the observed distributions of the 99 fish species at our sites to identify coolwater thermal boundaries. Coolwater streams had June-through-August mean water temperatures of 17.0–20.5°C, July mean temperatures of 17.5–21.0°C, and maximum daily mean temperatures of 20.7–24.6°C. We delineated two subclasses of coolwater streams: “cold transition” (having July mean water temperatures of 17.5–19.5°C) and “warm transition” (having July mean temperatures of 19.5–21.0°C). Fish assemblages in coolwater streams were variable and lacked diagnostic species but were generally intermediate in species richness and overlapped in composition with coldwater and warmwater streams. In cold-transition streams, coldwater (e.g., salmonids and cottids) and transitional species (e.g., creek chub Semotilus atromaculatus, eastern blacknose dace Rhynichthys atratulus, white sucker Catostomus commersonii, and johnny darter Etheostoma nigrum) were common and warmwater species (e.g., ictalurids and centrarchids) were uncommon; in warm-transition streams warmwater and transitional species were common and coldwater species were uncommon. Coolwater was the most widespread and abundant thermal class in Michigan and Wisconsin, comprising 65% of the combined total stream length in the two states (cold-transition streams being more common than warm-transition ones). Our approach can be used to identify and characterize coolwater streams elsewhere in the temperate region, benefiting many aspects of fisheries management and environmental protection.
Using Positional Data from Vessel Monitoring Systems to Validate the Logbook-Reported Area Fished and the Stock Allocation of Commercial Fisheries Landings
Authors: Palmer Michael C. , Wigley Susan E. 
Published: October 2009

Abstract
Stock allocations derived from vessel monitoring system (VMS) positional data from northeastern U.S. fisheries were compared with those obtained from mandatory vessel trip report (VTR) logbooks. A gear-specific speed algorithm was applied to VMS positions collected in 2005 from otter trawl, Atlantic sea scallop Placopecten magellanicus dredge, sink gill-net, and benthic longline fisheries to estimate the locations of fishing activity. Estimated fishing locations were used to reallocate the stock area landings of eight federally managed groundfish species. The accuracy of the VMS method relative to that of the mandatory logbooks was assessed using haul locations and catch data recorded by at-sea observers. The VMS algorithm tended to overestimate the number of statistical areas fished, such that when a trip's fishing activity occurred in a single statistical area, logbooks more accurately reflected the true fishing location. However, when fishing activity occurred in multiple statistical areas, the VMS algorithm showed appreciable gains relative to logbook data. Compared with mandatory logbooks, the VMS method achieved distributions of stock landings closer to observer estimates in 77.8% of the cases examined. The stock allocation percentages from both the VMS- and VTR-based methods were within 1.7% for all stocks, suggesting that the impacts on total stock allocations are relatively minor. However, these small differences represent major relative differences in stock landings for less abundant stocks such as southern New England–Mid-Atlantic yellowtail flounder Limanda ferruginea, where the VTR-based method allocated 61.9% more landings than the VMS-based method. The VMS-based method is not a replacement for the VTR-based method; however, it can and should be used as a tool to identify those vessels for which targeted outreach activities would improve the accuracy of VTR statistical area reporting.
An Assessment of Age Determination Methods for Great Lakes Larval Sea Lampreys
Authors: Dawson Heather A. , Jones Michael L. , Scribner Kim T. , Gilmore Stacy A. 
Published: October 2009

Abstract
Estimating the age composition and recruitment of populations of invasive sea lampreys Petromyzon marinus necessitates the validation and improvement of age assessment methods that rely on statoliths and length-frequency data. Determining age based on length-frequency distributions is subjective because of heterogeneity in the growth rates of larval sea lampreys (ammocoetes) within and across streams and the resulting overlap in lengths between age-classes. Statolith-based age assessment methods have never been validated for more than 1 year. We established “known-age” ammocoete populations in two streams by introducing a single cohort of spawners above barriers and compared estimates of ammocoete age based on statoliths with the true ages. In five additional streams, we used microsatellite data from adults and ammocoetes to assign parents to ammocoetes produced the same year and compared the age determined by statolith-based interpretation with the age based on parentage assignment. We combined length-frequency data with age composition data from streams having known-age populations and evaluated likelihood-based statistical models used to estimate the age composition of the ammocoete population. Multiple independent age readings of statoliths from known-age sea lampreys indicated that the age assessment bias (average percent error) was 24.3–36.2%. Genotype-based ages differed from statolith-based ages in 36.1% of cases across all streams. Bias-corrected statolith ages, when combined with length-frequency data, substantially increased age assessment accuracy in a known-age population stream and increased precision in a randomly selected stream; their use, however, requires knowledge of the magnitude of the bias of statolith-based age assessment in study streams. Further effort is needed to quantify these biases and generalize to different types of streams before a reliable methodology for age assessment will be available for sea lamprey management.
Fishery and Population Characteristics of Blue Catfish and Channel Catfish and Potential Impacts of Minimum Length Limits on the Fishery in Lake Wilson, Alabama
Authors: Holley Michael P. , Marshall Matthew D. , Maceina Michael J. 
Published: October 2009

Abstract
A popular recreational and commercial fishery for blue catfish Ictalurus furcatus and channel catfish I. punctatus exists at Lake Wilson, Alabama (Tennessee River). We examined the fishery, exploitation, angler size selectivity, and population demographics of these two species at Lake Wilson. In addition, we explored management strategies to enhance the fishery of trophy blue catfish. Currently, Alabama has no bag or minimum-length-limit regulations for catfish, except for the harvest of fish over 864 mm total length (TL). From April to October 2006, catfish harvest was high (8 kg/ha), and angler catch and harvest rates averaged 1.5 and 1.2 fish/h, respectively. The majority of fish harvested were between 300 and 600 mm TL, and anglers harvested larger fish in proportion to the sample population. Catfish were collected by low-frequency (15-MHz) DC electrofishing; they were aged with otoliths from 180 and 122 blue catfish and channel catfish, respectively, subsamples of 2,905 blue catfish and 699 channel catfish. Fish over 300 mm TL were tagged with Carlin dangler tags to estimate exploitation. Accounting for tag loss and variations in angler nonreporting rates (20–70%), we estimated that annual exploitation ranged from 8% to 22% for blue catfish and from 4% to 11% for channel catfish. Of the tagged fish harvested, 33% came from seven commercial fishers. Blue catfish and channel catfish displayed different life histories, which pointed to contrasting management strategies for increasing yield. Blue catfish were longer-lived (maximum age = 25 years), expressed slower growth (von Bertalanffy K = 0.081), and had lower natural mortality (M = 0.16) than channel catfish (maximum age = 12 years; von Bertalanffy K = 0.148; M = 0.29). Increasing minimum length limits from 300 to 660 mm for blue catfish would increase yield up to 50%, prevent growth overfishing, and increase the abundance of memorable-length (890-mm) blue catfish over our range of estimated exploitation. However, for channel catfish, minimum length limits greater than 300 mm would result in a lower yield. High length limits could drastically reduce the angler harvest of catfish but increase the abundance of memorable-length and larger blue catfish. Even so, the anglers surveyed preferred to harvest smaller fish. Fishing mortality was probably equal to natural mortality for blue catfish, but for channel catfish fishing mortality was less than natural mortality. On the basis of these observations, angler catches, the lack of angler species recognition, and the abundance of small catfish, we currently do not recommend bag or minimum length limits for this fishery.
Determination of Striped Bass Spawning Locations in the Two Major Tributaries of Lake Texoma
Authors: Baker William P. , Boxrucker Jeff , Kuklinski Kurt E. 
Published: October 2009

Abstract
Even though Lake Texoma is one of only four reservoir systems in the southeastern United States with a reproducing population of striped bass Morone saxatilis, spawning locations have not been determined. Recently proposed water development projects in the watershed make locating and protecting these locations a priority. The objectives of this study were to (1) determine where and when striped bass spawn in the Red and Washita rivers, (2) compare the relative densities of striped bass eggs collected in the two rivers, (3) determine the horizontal distribution of striped bass eggs in the Washita River, and (4) assess water-chemistry-related differences in the size of striped bass eggs between the two rivers. Striped bass eggs were classified into developmental stages and assigned ages (in hours) based on developmental temperature. Spawning areas were predicted from egg age and river current velocity as well as the presence of suitable habitat (verified visually). Striped bass spawning peaks generally followed stage rises in both rivers. Striped bass eggs were collected from 4 April to 18 May, 2001, in the Red River and from 3 April to 19 May, 2001, in the Washita River. Mean egg density peaked at 5 eggs/m3 on 16 April in the Red River and at 34.4 eggs/m3 on 21 April in the Washita River. We found no relationship between spawning distance from the lake and discharge. Direct comparison of egg catches in the two rivers may be misleading due to differences in channel morphology. However, in the Washita River, we found no horizontal difference in egg density across the river channel. Management agencies should exercise caution with respect to the implementation of water development projects within the watershed that could alter river flow or water chemistry, as these are probably key to the continued reproductive success of striped bass in the Lake Texoma system.