bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effectiveness and Retention of Thiamine and Its Analogs Administered to Steelhead and Landlocked Atlantic Salmon
Authors: Ketola H. George , Isaacs Gary R. , Robins Jeffrey S. , Lloyd Russell C. 
Published: February 2008

Abstract
We investigated the feasibility of enhancing the reproduction of steelhead Oncorhynchus mykiss and landlocked Atlantic salmon Salmo salar in lakes where the consumption of alewives Alosa pseudoharengus and other forage fishes containing thiaminase can cause them to become thiamine deficient and thereby reduce the survival of their fry. We evaluated feeding fingerling steelhead excess thiamine hydrochloride (THCl) for 1 or 2 weeks or equimolar amounts of thiamine mononitrate, thiamine-tetrahydro-furfuryl-disulfide, benfotiamine, or dibenzoyl thiamine (DBT). We found minimal internal reserves of thiamine after 6 months. We also compared the ability of injections of thiamine and its analogs to prevent mortality in thiamine-deficient steelhead and Atlantic salmon sac fry and found all forms to be effective, although benfotiamine was the least effective on an equimolar basis. Further, we injected yearling steelhead and found that DBT was tolerated at approximately 11,200 nmol/g of body weight, about 10 times more than thiamine in any other form. When yearling steelhead were injected with near-maximal doses of thiamine hydrochloride and several analogs and then fed a thiamine-deficient diet, DBT was retained for approximately 2 years—in contrast to other forms, which were retained for less than about 6 months. Therefore, these results suggest that neither feeding nor injecting young hatchery salmonids with DBT is likely to enhance their reproduction for more than 2 years after stocking. However, injecting DBT in nearly mature fish (either cultured fish from hatcheries or wild fish captured in lakes) may provide them with enough thiamine to successfully spawn within 2 years even though they consume mainly thiaminase-containing forage fishes.
Contribution of Terrestrial Invertebrates to Yearly Brook Trout Prey Consumption and Growth
Authors: Sweka John A. , Hartman Kyle J. 
Published: February 2008

AbstractTerrestrial invertebrates are an important component of stream fish diets, especially during the summer months, when aquatic invertebrates are limited. The seasonal diet composition of the brook trout Salvelinus fontinalis inhabiting two West Virginia streams was used in a bioenergetics model to simulate yearly prey consumption for two cohorts of age‐1 brook trout in each stream. Baseline simulations were run by fitting the model to observed growth from June 2000 to June 2001 for the first cohort and from June 2001 to June 2002 for the second cohort. Terrestrial invertebrate inputs can be negatively impacted by anthropogenic effects (e.g., timber harvest and pesticide application). To determine the degree to which growth would be suppressed by a reduction in terrestrial invertebrate consumption, we ran simulations in which the amount of terrestrial invertebrate consumption was reduced by 25, 50, 75, and 100%. Simulations were then run to determine the consumption of aquatic invertebrates that would be necessary to compensate for a reduction in terrestrial invertebrate consumption. The baseline simulations showed that terrestrial invertebrates accounted for 38‐47% of the biomass consumed annually and 51‐63% of the energy consumed. Reductions in the amount of terrestrial invertebrates in the diet of brook trout reduced growth; to maintain the same growth, brook trout would need to increase yearly consumption of aquatic invertebrates by more than 100% in the absence of terrestrial invertebrate input. These modeling results illustrate the importance of terrestrial invertebrates to headwater stream fish production, and managers need to recognize this energy source in assessing a stream's potential to support fish and in managing riparian forests.
An Overview of Methods for Developing Bioenergetic and Life History Models for Rare and Endangered Species
Authors: Petersen James H. , DeAngelis Donald L. , Paukert Craig P. 
Published: February 2008

AbstractMany fish species are at risk to some degree, and conservation efforts are planned or underway to preserve sensitive populations. For many imperiled species, models could serve as useful tools for researchers and managers as they seek to understand individual growth, quantify predator‐prey dynamics, and identify critical sources of mortality. Development and application of models for rare species however, has been constrained by small population sizes, difficulty in obtaining sampling permits, limited opportunities for funding, and regulations on how endangered species can be used in laboratory studies. Bioenergetic and life history models should help with endangered species‐recovery planning since these types of models have been used successfully in the last 25 years to address management problems for many commercially and recreationally important fish species. In this paper we discuss five approaches to developing models and parameters for rare species. Borrowing model functions and parameters from related species is simple, but uncorroborated results can be misleading. Directly estimating parameters with laboratory studies may be possible for rare species that have locally abundant populations. Monte Carlo filtering can be used to estimate several parameters by means of performing simple laboratory growth experiments to first determine test criteria. Pattern‐oriented modeling (POM) is a new and developing field of research that uses field‐observed patterns to build, test, and parameterize models. Models developed using the POM approach are closely linked to field data, produce testable hypotheses, and require a close working relationship between modelers and empiricists. Artificial evolution in individual‐based models can be used to gain insight into adaptive behaviors for poorly understood species and thus can fill in knowledge gaps.
Development and Evaluation of a Bioenergetics Model for the Inland Silverside in Freshwater Systems
Authors: Chizinski Christopher J. , Huber Caleb G. , Pope Kevin L. 
Published: February 2008

AbstractConsumption and respiration parameters were fit for inclusion in a bioenergetics model developed to predict the growth of the inland silverside Menidia beryllina. Although this model accurately predicted inland silverside growth through the initiation of spawning, it failed to predict the growth of reproductively active inland silversides. Model simulations provided initial evidence that a single model cannot predict the lifetime growth patterns of this species. Instead, a two‐stage model is probably necessary to account for the physiological differences between the prespawning and active‐spawning stages. In addition, the bioenergetics models of short‐lived (life span, <2 years) fishes may need to include a better means for assessing the direct energy expenditure for reproduction.
A Bioenergetics Approach to Modeling Striped Bass and Threadfin Shad Predator‐Prey Dynamics in Lake Powell, Utah‐Arizona
Authors: Vatland Shane , Budy Phaedra , Thiede Gary P. 
Published: February 2008

AbstractAn understanding of the mechanisms driving the cyclic relationship between piscivorous sport fish and their food base is needed in systems where predator and prey are tightly coupled. To understand the dynamics between striped bass Morone saxatilis and threadfin shad Dorosoma petenense in Lake Powell, Utah‐Arizona, we (1) synthesized and evaluated 20 years of historical data on temperature, diet, growth, and abundance of these fish, (2) collected similar data on a finer scale in 2003‐2004, (3) used components of this data set to develop specific conversions between coarser historic data and present data, and (4) modeled striped bass and threadfin shad dynamics within a bioenergetics framework. We estimated the consumption of threadfin shad by age‐0, subadult, and adult striped bass in Lake Powell from 1985 to 2003. During this period, threadfin shad abundance peaked at approximately 5‐ to 7‐year intervals and striped bass growth, condition, and abundance corresponded closely to peaks in threadfin shad foraging. Individual consumption of threadfin shad by striped bass was highest for adults followed by subadult and age‐0 fish; scaling individual consumption up to the population level resulted in highly variable subadult consumption that fluctuated from highs of about 1.2 million kg (18.4 kg/ha) to lows of about 0.3 million kg (4.6 kg/ha) on a 1‐ to 2‐year cycle. Despite these fluctuations, the consumption of threadfin shad was dominated by subadult striped bass, which appeared to control threadfin shad numbers in all but the highest peak years of shad abundance. Based on bioenergetics output, striped bass demonstrate a type II functional feeding response; consumption rates reach an asymptote when the threadfin shad biomass index exceeds 10,000 kg/year. We demonstrate a modeling approach that allowed us to evaluate the large fluctuations in predator and prey populations, which often become evident only over long time periods. Our results increase our understanding of the Lake Powell ecosystem and highlight areas for future study.
Individual Variation in Bioenergetic Rates of Young‐of‐Year Rainbow Trout
Authors: Tyler Jeffrey A. , Bolduc Melanie B. 
Published: February 2008

AbstractStudies collecting data on bioenergetic rates in fish typically measure the rates of a large number of individuals once and then fit parameters to those data sets. Such data commonly have large amounts of variation around the mean, which is left unexplained because the study aims to address population‐level or ecosystem‐level questions. We addressed the question of whether individual fish have detectably different rates of maximum consumption and respiration rates by repeatedly measuring those rates in individually identified young‐of‐year (age‐0) rainbow trout Oncorhynchus mykiss over a range of temperatures. In experiment 1 we measured the respiration rates of two size‐classes of age‐0 rainbow trout five times at five different temperatures (9‐19°C). In experiment 2 we measured the respiration and maximum feed consumption rates of one size‐class of rainbow trout five times at four different temperatures (7‐19°C). We also use these data to develop a new parameter set for a Wisconsin bioenergetics model of maximum consumption and respiration rates for age‐0 rainbow trout. The results show that individual differences have a significant effect on their respiration and maximum feed consumption rates. The new bioenergetics parameter set differs considerably from the parameter sets developed for adult rainbow trout. The new bioenergetics model may prove useful for studies examining the growth and feed consumption of age‐0 rainbow trout. The finding of significant differences between individuals in measured rates of respiration and maximum consumption may be important in individual‐based models (IBMs) of fish populations. Specifically, IBMs have not included individual‐level differences in bioenergetic rates, but such differences may have an important effect on their predictions of fish growth, production, and population number.
Effects of Age‐1 Striped Bass Predation on Juvenile Fish in Western Albemarle Sound
Authors: Tuomikoski Jack E. , Rudershausen Paul J. , Buckel Jeffrey A. , Hightower Joseph E. 
Published: February 2008

AbstractHistorically, the fisheries for adult river herring (i.e., alewife Alosa pseudoharengus and blueback herring A. aestivalis) and American shad A. sapidissima were economically important in Albemarle Sound, North Carolina. Stocks of these species are in decline, while stocks of striped bass Morone saxatilis have increased roughly 10‐fold in the Albemarle Sound‐Roanoke River since the early 1990s. The goal of this study was to quantify the predatory impact of age‐1 striped bass on age‐0 prey fishes by estimating striped bass consumption rates and comparing loss rates from predation with total prey loss rates using catch curves. Age‐1 striped bass and their potential prey were collected with beach and purse seines from western Albemarle Sound from spring to fall, 2002 and 2003. Commercially and ecologically important prey in one or both years included river herring, American shad, Atlantic menhaden Brevoortia tyrannus, and yellow perch Perca flavescens. Predation by age‐1 striped bass had a marked effect on juvenile American shad densities in 2002 but little effect in 2003. Conversely, predation by age‐1 striped bass explained none of the loss in juvenile yellow perch in 2002 but accounted for nearly all of the loss early in 2003. In most cases, predation by age‐1 striped bass did not greatly influence juvenile alewife numbers. Juvenile blueback herring were preyed on during late summer and fall, but the predatory impact could not be confirmed because of apparent downstream emigration into the study area. Thus, for some species, these predator‐prey linkages are important in determining year‐class strength and should be incorporated into multispecies population models.
Occurrences and ecological risks of roxithromycin, trimethoprim, and chloramphenicol in the Han River, Korea
Authors: Choi Kyungho , Kim Younghee , Jung Jinyong , Kim Myung-Hyun , Kim Chang-Soo , Kim Nam-Hee , Park Jeongim 
Published: February 2008

Abstract
We evaluated the occurrence of three antibiotics (roxithromycin, trimethoprim, and chloramphenicol) in surface water and effluents from several sewage treatment plants (STPs) on the Han River, Korea. In addition, standard acute toxicity tests were conducted using the microbe Vibrio fischeri, freshwater macroinvertebrates Daphnia magna and Moina macrocopa, and fish (Oryzias latipes) for these antibiotics. Antibiotics were more frequently detected at higher amounts in effluent samples and in samples collected during the low-flow season. For trimethoprim and chloramphenicol, the levels observed in surface water during low flow were, on average, 108 and 31 ng/L, respectively. These levels were comparable to those measured in the municipal effluents (average, 80 and 37 ng/L, respectively), suggesting the presence of other sources upstream (e.g., livestock wastes). For roxithromycin, surface water levels were approximately an order of magnitude lower than effluent levels. Adverse effects of roxithromycin, trimethoprim, and chloramphenicol were observed at mg/L levels in standard acute aquatic ecotoxicity tests. Based on hazard quotients calculated for the three antibiotics, minimal risks to aquatic systems are suggested. To further increase scientific understanding about the potential impacts of these pharmaceuticals in the environment, however, chronic ecotoxicology studies, with more subtle but ecologically meaningful end points or in combination with other mechanistically related contaminants, may be beneficial.
Assessment of exposure risk of polychlorinated biphenyls to interior least terns (Sterna antillarum)
Authors: Sanchez Brian C , Caldwell Colleen A 
Published: February 2008

AbstractRisk of polychlorinated biphenyl (PCB) exposure and effects were assessed for a colony of federally endangered interior least terns (Sterna antillarum) nesting on the Bitter Lake National Wildlife Refuge (NM, USA). The colony feeds from an area on the Refuge (Hunter Marsh/Oxbow Complex) wherein fish with elevated concentrations of total PCBs have been documented. Concentrations of total PCBs in whole fish averaged 0.94 mg/kg with a maximum concentration of 2.77 mg/kg, wet weight. Estimated daily PCB intake rates by adult birds throughout their 180-d breeding season ranged from &lt;0.01 mg/kg/d to 0.98 mg/kg/d, yielding hazard quotients that ranged from 0.01 to 21.68. Polychlorinated biphenyls pose a moderate risk to the colony of interior least terns that breed at the Bitter Lake National Wildlife Refuge, but the exposure rate is not likely to threaten their overall breeding success.
DNA Microarray-based ecotoxicological biomarker discovery in a small fish model species
Authors: Wang Rong-Lin , Bencic David , Biales Adam , Lattier David , Kostich Mitch , Villeneuve Dan , Ankley Gerald T , Lazorchak Jim , Toth Greg 
Published: February 2008

AbstractAs potential biomarkers, gene classifiers are gene expression signatures or patterns capable of distinguishing biological samples belonging to different classes or conditions. This is the second of two papers on profiling gene expression in zebrafish (Danio rerio) treated with endocrine-disrupting chemicals of different modes of action, with a focus on comparative analysis of microarray data for gene classifier discovery. Various combinations of gene feature selection/class prediction algorithms were evaluated, with the use of microarray data organized by a chemical stressor or tissue type, for their accuracy in determining the class memberships of independent test samples. Two-way clustering of gene classifiers and treatment conditions offered another alternative to assess the performance of these potential biomarkers. Both gene feature selection methods and class prediction algorithms were shown to be important in identifying successful gene classifiers. The genetic algorithm and support vector machine yielded classifiers with the best prediction accuracy, regardless of sample size, nature of class prediction, and data complexity. A chemical stressor significantly altering the expression of a greater number of genes tended to generate gene classifiers with better performance. All combinations of gene feature selection/class prediction algorithms performed similarly well with data of high signal to noise ratio. Gene classifier discovery and application on the basis of individual sampling and sample data pooling, respectively, were found to enhance class predictions. Gene expression profiles of the top gene classifiers, identified from both microarray and quantitative polymerase chain reaction assays, displayed greater similarity between fadrozole and 17β-trenbolone than either one to 17α-ethinylestradiol. These gene classifiers could serve as potential biomarkers of exposure to specific classes of endocrine disruptors.
Altered reproduction in fish exposed to pulp and paper mill effluents: Roles of individual compounds and mill operating conditions
Authors: Hewitt L. Mark , Kovacs Tibor G , Dubé Monique G , MacLatchy Deborah L , Martel Pierre H , McMaster Mark E , Paice Michael G , Parrott Joanne L , van den Heuvel Michael R , van der Kraak Glen J 
Published: February 2008

AbstractFor the last 20 years, studies conducted in North America, Scandinavia, and New Zealand have shown that pulp and paper mill effluents affect fish reproduction. Despite the level of effort applied, few leads are available regarding the factors responsible. Effluents affect reproduction in multiple fish species, as evidenced by decreased gonad size, decreased circulating and gonadal production of reproductive steroids, altered expression of secondary sex characteristics, and decreased egg production. Several studies also have shown that effluent constituents are capable of accumulating in fish and binding to sex steroid receptors/binding proteins. Studies aimed at isolating biologically active substances within the pulping and papermaking process have provided clues about their source, and work has progressed in identifying opportunities for in-mill treatment technologies. Following comparisons of manufacturing processes and fish responses before and after process changes, it can be concluded that effluent from all types of mill processes are capable of affecting fish reproduction and that any improvements could not be attributed to a specific process modification (because mills normally performed multiple modifications simultaneously). Improved reproductive performance in fish generally was associated with reduced use of molecular chlorine, improved condensate handling, and liquor spill control. Effluent biotreatment has been effective in reducing some effects, but biotreated effluents also have shown no difference or an exacerbation of effects. The role of biotreatment in relation to effects on fish reproduction remains unclear and needs to be resolved.
Net trophic transfer efficiencies of polychlorinated biphenyl congeners to lake whitefish (Coregonus clupeaformis) from their food
Authors: Madenjian Charles P , O'Connor Daniel V , Rediske Richard R , O'Keefe James P , Pothoven Steven A 
Published: February 2008

Abstract
Lake whitefish (Coregonus clupeaformis) were fed rainbow smelt (Osmerus mordax) in four laboratory tanks over a 133-d experiment. At the start of the experiment, 10 to 14 of the fish in each tank were sacrificed, and the concentrations of 40 polychlorinated biphenyl (PCB) congeners within these fish were determined. Polychlorinated biphenyl congener concentrations were also determined in the 15 lake whitefish remaining in each of the four tanks at the end of the experiment as well as in the rainbow smelt fed to the lake whitefish. Each lake whitefish was weighed at the start and the end of the experiment, and the amount of food eaten by the lake whitefish during the experiment was tracked. Using these measurements, net trophic transfer efficiency (γ) from the rainbow smelt to the lake whitefish in each of the four tanks was calculated for each of the 40 PCB congeners. Results showed that γ decreased exponentially as log KOW for the congeners increased from 6 to 8. Further, γ averaged 0.70 for the tetrachloro congeners but averaged only 0.45 for the higher chlorinated congeners.
Electron-microscopic localization of lipophilic chemicals by an antibody-based detection system using the blue mussel Mytilus edulis as a model system
Authors: Einsporn Sonja , Koehler Angela 
Published: February 2008

Abstract
Identification of lipophilic chemicals requires the development of new techniques to detect these compounds at the cellular and subcellular levels. To address this issue, we have developed a combinational protocol using antibodies directed against chemicals together with a multiple signal amplification system (catalyzed signal amplification/gold-substituted silver-intensified peroxidase) to detect the lipophilic compounds at their subcellular sites of accumulation by transmission electron microscopy. As a model organism, we exposed the blue mussel Mytilus edulis to the polycyclic aromatic hydrocarbon phenanthrene and the polychlorinated biphenyl mixture Aroclor 1254 for up to 10 d. The aim of these exposure experiments was to analyze the cellular targets and sites of accumulation in the digestive system by transmission electron microscopy. The endo-lysosomal system of digestive cells and mitochondria of epithelial cells appeared to be the preferred accumulation sites for the lipophilic compounds studied. The antibody-based approach to detect lipophilic chemicals provides an important insight into the pathways of uptake and accumulation as well as mechanisms of toxicity.