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At least 37 records · Page 2Linked to original sources
USGS1993

Fish meal and alternate sources of protein in fish feeds: Update 1993

Close to 12% of the world's 6.5 million metric tons of fish meal is used for aquaculture feeds. If current trends continue, roughly 20% to 25% of total world fish meal production could be used for aquaculture by the year 2000. Fish stocks used in fish meal reduction, however, appear to be in worldwide decline. A growing fish farming industry and a stagnating, if not diminishing, supply of fish meal have sobering economic and technologic implications for fish culture. Unless suitable alternate protein sources are found or other animal feeds begin to rely less on fish meal, fish production costs can be expected to increase dramatically. A precedent was set by the poultry industry, the most economically successful and competitive of the animal agriculture industries. Twenty years ago, the poultry industry consumed up to 80% of fish meal supplies. Through deliberate and well-organized research into alternate protein sources, the industry now uses less than 40% of supplies, and the trend is toward complete independence from fish meal. A comparable research effort is needed for aquaculture. Considering the biotechnologies available, plant proteins, processed to remove enzyme inhibitors and other antinutritional factors and properly supplemented with essential amino acids and minerals where needed, could produce results at least equivalent to those obtained with fish meal.

Fisheries↗
USGS2023

Migration, breeding location, and seascape shape seabird assemblages in the northern Gulf of Mexico

The Gulf of Mexico supports many seabird species, yet data gaps describing species composition and habitat use are prevalent. We used vessel-based observations from the Gulf of Mexico Marine Assessment Program for Protected Species to identify and characterize distinct seabird assemblages in the northern Gulf of Mexico (within the U.S. Exclusive Economic Zone; nGoM). Using cluster analysis of 17 seabird species, we identified assemblages based on seabird relative density. Vessel-based surveys documented the location, species, and number of seabirds across the nGoM between 2017–2019. For each assemblage, we identified the (co-)dominant species, spatial distribution, and areas of greater relative density. We also assessed the relationship of the total relative density within each assemblage with environmental, spatial, and temporal covariates. Of the species assessed, 76% (n = 13) breed predominantly outside the nGoM basin. We identified four seabird assemblages. Two assemblages, one dominated by black tern and the other co-dominated by northern gannet/laughing gull, occurred on the continental shelf. An assemblage dominated by sooty tern occurred along the continental slope into pelagic waters. The fourth assemblage had no dominant species, was broadly distributed, and was composed of observations with low relative density (‘singles’ assemblage). Differentiation of assemblages was linked to migratory patterns, residency, and breeding location. The spatial distributions and relationships of the black tern and northern gannet/laughing gull assemblages with environmental covariates indicate associations with river outflows and ports. The sooty tern assemblage overlapped an area prone to mesoscale feature formation. The singles assemblage may reflect commuting and dispersive behaviors. These findings highlight the importance of seasonal migrations and dynamic features across the seascape, shaping seabird assemblages. Considering the potential far-ranging effects of interactions with seabirds in the nGoM, awareness of these unique patterns and potential links with other fauna could inform future monitoring, research, restoration, offshore energy, and aquaculture development in this highly industrialized sea.

Gulf of Mexico↗
USGS2023

A review of grass carp and related species literature on diet, behavior, toxicology, and physiology focused on informing development of controls for invasive grass carp populations in North America

Grass carp ( Ctenopharyngodon idella ) are globally important in aquaculture and aquatic vegetation control. However, escaped grass carp have established invasive populations. A targeted keyword search was performed on a carp (order: Cypriniformes) literature database maintained by the U.S. Geological Survey to identify literature relevant to grass carp. Additional sources cited in reviewed documents and provided by numerous reviewers were also included. There were three focus areas designed to provide support for invasive grass carp management: (1) diet and behavior; (2) physiological constraints, toxicity, and biology; and (3) gut physiology. Each focus area provides information to guide development of potential pathways for invasive grass carp control. Information from other carp species was used to fill in gaps where grass carp information was lacking and provide additional, potential research directions. Diet-related information included food selection and aquacultural diet formulations. Behavioral information included stimuli and non-physical barriers to attract, repel, or stop movement. Physiological constraints, toxicology, reproductive control, and biological control provide a research review for control options. Gut physiology and related control pathways provide knowledge to improve toxin or pathogen delivery. This review provides a basis for developing approaches and research for controlling invasive grass carp populations, aquaculture, and native population management.

Fishes↗
USGS1982

Fish culture: an annotated bibliography of publications of the National Fisheries Center, Leetown, 1972-1980

This is an annotated bibliography of the publications authored or co-authored by the staff of the National Fisheries Center - Leetown (NFC-L) from 1972 through 1980. It includes publications from NFC-L staff at the Fish Farming Experimental Station, Stuttgart, AR; the Fish Genetics Laboratory, Beulah, WY; the Hagerman Field Station of the Tunison Laboratory of Fish Nutrition, Hagerman, ID; the National Fisheries Research and Development Laboratory, Marison, AL; and, the Tunison Laboratory of Fish Nutrition, Cortland, NY. It also includes publications from NFC-L staff at the Aquaculture Production/Demonstration Station, Fisheries Academy, Fish Genetics Station, National Fish Health Research Laboratory, and Technical Information Services, each located in Kearneysville, WV. Prior to 1977, each functioned as a separate entity within the U.S. Fish and Wildlife Service. In 1977, the administrative and program activities of these components were merged into the Natkonal Fisheries Center. This bibliography lists the publications issued by each of these entities both before and after becoming joined into the Center. Publications from these components prior to 1972 are documents in U.S. Bureau of Sport Fisheries and Wildlife, Resource Publication 120, Bibliography of Research Publications of the U.S. Bureau of Sport Fisheries and Wildlife, 1928-72 . Entries in this bibliography are arranged under broad subject categories, similar to those used in U.S. Fish and Wildlife Service, Sport Fishery Abstracts . Within these categories, the publications are then arranged alphabetically by author and sequentially by date of publication. They cover a wide range of scientific and technical disciplines applicable to the field of aquaculture. The annotations were submitted by each NFC-L component, and were modified to some extent for uniformity. An author index is included at the end of the bibliography.

Report↗
USGS2023

Stocking fish in inland waters: Opportunities and risks for sustainable food systems

Stocking is one of the foremost tools in the inland fisheries management toolbox, but it comes with both opportunities and risks. Stocking is often used as compensation for depleted wild populations, particularly where recruitment processes have been disrupted, but it can introduce disease, disrupt community structures, reduce genetic integrity, and cause conflicts between fishery stakeholders. Despite its widespread use, examples of effective stocking for food fisheries in inland waters are sparse in the peer-reviewed literature. Nevertheless, it is well established that stocking is frequently used to maintain fish yield, so there is a need to conduct the practice in a robust manner that minimises the potential risks. This paper serves as the front matter for a special section of Fisheries Management and Ecology focused on fresh waters feeding the world, which resulted from two panel sessions, one focused on aquaculture and one focused on stocking, hosted by the international InFish research network ( https://infish.org/ ). The paper highlights current practices of fish stock enhancement in inland waters for food, examines potential synergies and interactions of stock enhancement programmes with aquaculture, and provides an outline framework for responsible management of fish stock enhancement.

Fisheries Management and Ecology↗
USGS1995

The ecology of cormorants: some research needs and recommendations

Concerns about Double-crested Cormorants (Phalacrocorax auritus) have arisen because of their rapid population increase across North America and their economic impact on several aquaculture and commercial fish industries. In spite of the concern for cormorants, little published research is available that addresses either basic population biology questions or management issues. Based on a literature review, I recommend that research be conducted in four areas. First, a large-scale banding and marking program should be initiated so that population models can be used to estimate age- and sex-specific survival and fecundity (as has been done for the Shag [P. aristotelis] in Europe). By marking individual birds, survival and movement rates can be estimated between nesting colonies, which will provide information about potential source versus sink colonies. Second, studies of movements during migration and winter are required. Presently, no data are available on habitat use during migration or on the length-of-stay by individual birds. This has important implications to how cormorants interact with other fish and wildlife species over a broad range. Studies of movements during winter with radio-marked birds should indicate whether the 'problem birds' at aquaculture sites are merely a few specialists. Third, limiting factors, such as contaminants and disease, should receive further investigation, especially in light of recent concerns over the outbreak of Newcastle disease. The relationship between contaminant levels and developmental abnormalities in young cormorants in certain areas of the Great Lakes in Canada and the United States remains equivocal. Fourth, further studies are needed to document the economic impacts of cormorants on Channel Catfish (Ictalurus punctatus) and other cultured fishes and to determine ways to reduce predation by fish-eating birds. Mesocosm experiments should be conducted to evaluate how different fish extraction rates affect final productivity of fish. Controlled experiments with different exclusion and scaring devices are needed. With radio-marked birds, it should be determined what the behavioral responses are to the different scaring devises. Also, providing alternative wetland feeding sites in regions of fish farm depredation might alleviate some of the pressure on farmers. Studies with radio-marked birds could evaluate effects of manipulation of 'natural' wetlands on use by birds during the winter period. Finally, any research directed at the Double-crested Cormorant should also evaluate its interactions with other fisheating waterbirds.

Book chapter↗
USGS2007

Hydrogeologic Setting and Ground-Water Flow in the Leetown Area, West Virginia

The Leetown Science Center is a research facility operated by the U.S. Geological Survey that occupies approximately 455-acres near Kearneysville, Jefferson County, West Virginia. Aquatic and fish research conducted at the Center requires adequate supplies of high-quality, cold ground water. Three large springs and three production wells currently (in 2006) supply water to the Center. The recent construction of a second research facility (National Center for Cool and Cold Water Aquaculture) operated by the U.S. Department of Agriculture and co-located on Center property has placed additional demands on available water resources in the area. A three-dimensional steady-state finite-difference ground-water flow model was developed to simulate ground-water flow in the Leetown area and was used to assess the availability of ground water to sustain current and anticipated future demands. The model also was developed to test a conceptual model of ground-water flow in the complex karst aquifer system in the Leetown area. Due to the complexity of the karst aquifer system, a multidisciplinary research study was required to define the hydrogeologic setting. Geologic mapping, surface- and borehole-geophysical surveys, stream base-flow surveys, and aquifer tests were conducted to provide the hydrogeologic data necessary to develop and calibrate the model. It would not have been possible to develop a numerical model of the study area without the intensive data collection and methods developments components of the larger, more comprehensive hydrogeologic investigation. Results of geologic mapping and surface-geophysical surveys verified the presence of several prominent thrust faults and identified additional faults and other complex geologic structures (including overturned anticlines and synclines) in the area. These geologic structures are known to control ground-water flow in the region. Results of this study indicate that cross-strike faults and fracture zones are major avenues of ground-water flow. Prior to this investigation, the conceptual model of ground-water flow for the region focused primarily on bedding planes and strike-parallel faults and joints as controls on ground-water flow but did not recognize the importance of cross-strike faults and fracture zones that allow ground water to flow downgradient across or through less permeable geologic formations. Results of the ground-water flow simulation indicate that current operations at the Center do not substantially affect either streamflow (less than a 5-percent reduction in annual streamflow) or ground-water levels in the Leetown area under normal climatic conditions but potentially could have greater effects on streamflow during long-term drought (reduction in streamflow of approximately 14 percent). On the basis of simulation results, ground-water withdrawals based on the anticipated need for an additional 150 to 200 gal/min (gallons per minute) of water at the Center also would not seriously affect streamflow (less than 8 to 9 percent reduction in streamflow) or ground-water levels in the area during normal climatic conditions. During drought conditions, however, the effects of current ground-water withdrawals and anticipated additional withdrawals of 150 to 200 gal/min to augment existing supplies result in moderate to substantial declines in water levels of 0.5-1.2 feet (ft) in the vicinity of the Center's springs and production wells. Streamflow was predicted to be reduced locally by approximately 21 percent. Such withdrawals during a drought or prolonged period of below normal ground-water levels would result in substantial declines in the flow of the Center's springs and likely would not be sustainable for more than a few months. The drought simulated in this model was roughly equivalent to the more than 1-year drought that affected the region from November 1998 through February 2000. The potential reduction in streamflow is a result of capture of ground water tha

Scientific Investigations Report↗
USGS2019

Establishing genome sizes of focal fishery and aquaculture species along Baja California, Mexico

Genome size—the total haploid content of nuclear DNA— is constant in all cells in individuals within a species, but differs among species. Consequently, the genome size is a quantifiable genetic signature that not only characterizes a species, but it can reflect chromatin modifications, which play fundamental roles in most biological processes that are involved in the manipulation and expression of DNA. This characteristic makes the genome size a crucial parameter for genetic research on endemic aquatic species and for genetic manipulations in aquaculture species. Technologies for genetic assessments and improvements applied to fishery and aquaculture species use genome size values as a means by which hybrids, polyploids, and sex can be identified, when sex chromosomes exist. The objectives of this study were to determine genome sizes of aquatic species with economic and biological importance along the Pacific coast of Mexico, as well as to identify the appropriate reference standards for use in this study. Blood, hemolymph or milt were collected from 10 species occurring along the coast of Baja California: Sablefish Anoplopoma fimbria , Black Snapper Lutjanus novemfasciatus , California Halibut Paralichthys californicus , Pacific Sardine Sardinops sagax , Flag Rockfish Sebastes rubrivinctus , Starry Rockfish Sebastes constellatus, Totoaba Totoaba macdonaldi , Whiteleg Shrimp Litopenaeus vannamei and two Yellowtail Seriola lalandi and S. dorsalis . Nuclear DNA was stained with propidium iodide solution and the genome size was determined by flow cytometry, with results ranging from 0.61 pg (1.22 pg/diploid cell) to 2.59 pg (5.18 pg/diploid cell), with the smallest value in Sablefish and the largest in the Whiteleg Shrimp. No significant differences were detected ( P ≤ 0.05) among individuals of the same species; the likely reason behind any dissimilar DNA content values with those from the literature were differences in methodologies or variations in genetics. Red-ear Slider Turtle Trachemys scripta elegans 2.65 pg (5.30 pg/diploid cell) and Red Junglefowl Gallus gallus 1.27 pg (2.54 pg/diploid cell) were chosen as the standards for reference values. These results establish the basis for the Mexican National Aquatic Genetic Resources project supporting genetic improvements for aquaculture and conservation status parameters for fisheries species.

Baja California↗
USGS2017

Designing a global assessment of climate change on inland fishes and fisheries: knowns and needs

To date, there are few comprehensive assessments of how climate change affects inland finfish, fisheries, and aquaculture at a global scale, but one is necessary to identify research needs and commonalities across regions and to help guide decision making and funding priorities. Broadly, the consequences of climate change on inland fishes will impact global food security, the livelihoods of people who depend on inland capture and recreational fisheries. However, understanding how climate change will affect inland fishes and fisheries has lagged behind marine assessments. Building from a North American inland fisheries assessment, we convened an expert panel from seven countries to provide a first-step to a framework for determining how to approach an assessment of how climate change may affect inland fishes, capture fisheries, and aquaculture globally. Starting with the small group helped frame the key questions (e.g., who is the audience? What is the best approach and spatial scale?). Data gaps identified by the group include: the tolerances of inland fisheries to changes in temperature, stream flows, salinity, and other environmental factors linked to climate change, and the adaptive capacity of fishes and fisheries to adjust to these changes. These questions are difficult to address, but long-term and large-scale datasets are becoming more readily available as a means to test hypotheses related to climate change. We hope this perspective will help researchers and decision makers identify research priorities and provide a framework to help sustain inland fish populations and fisheries for the diversity of users around the globe.

Reviews in Fish Biology and Fisheries↗
USGS2026

The value of electronic tagging and tracking studies for understanding fish–hypoxia interactions

Objective Hypoxia (i.e., low dissolved oxygen availability) is a natural phenomenon but can also be induced by human activities (e.g., nutrient enrichment from runoff). Given that dissolved oxygen is essential for aquatic life, periods of hypoxia tend to have negative consequences (e.g., sublethal disturbances, mortality) for most fishes. Extensive laboratory research has documented hypoxia thresholds and physiological and behavioral outcomes for a variety of freshwater and marine fishes and there is also an extensive body of fieldwork assessing population-level responses (e.g., survival, distribution). Yet, studying how individual fish respond to hypoxia in the wild has proved challenging; electronic tagging and tracking tools (e.g., biotelemetry, biologging) have made it easier to study individual responses to hypoxia and complement other tools like hydroacoustics that tend to focus on population-level responses. Methods We review what has been learned from contemporary studies that employ electronic tagging and tracking tools to understand how fish respond to hypoxia in the wild. Topics explored include identifying and validating hypoxia thresholds, habitat compression, connectivity, mortality, physiological and bioenergetic consequences, and extreme weather conditions. We also consider what we have learned about evaluating various management plans for hypoxia and reflect on how electronic tags have also been used in aquaculture systems and in hybrid studies that combine laboratory and field research. We highlight fishes in Lake Erie as a research narrative to demonstrate how electronic tagging and tracking have markedly improved our understanding of a longstanding hypoxia issue. Results Our synthesis revealed that electronic tagging and tracking have provided critical information on how fish respond to hypoxia in the field, revealing complex trade-offs and compensatory mechanisms as well as cryptic hypoxia-induced mortality. Beyond just illuminating space use and mortality, tags equipped with various sensors are revealing how fish deal with hypoxia in real time in terms of physiology, bioenergetics, and behavior. Conclusions As electronic tagging and tracking methods experience further innovation and are increasingly applied to understand the effects of hypoxia on fish, we expect more unanticipated findings about the effects of hypoxia on fish in all aquatic ecosystems, which will strengthen our ability to manage and mitigate hypoxia. Combining tools and approaches (e.g., lab and field) is perhaps the best way to generate comprehensive understanding.

Transactions of the American Fisheries Society↗
USGS1996

The relevance of the Mediterranean Region to colonial waterbird conservation

The Mediterranean Sea is the largest partially enclosed sea in the world and provides habitat to more than 100 species of waterbirds from the Palearctic-North African-Middle Eastern regions. Even though the Mediterranean suffers from pollution, has little tidal influence, and is oligotrophic, more than half of the western Palearctic populations of numerous waterfowl species winter in the region. Thirty-three species of colonial waterbirds breed along the 46,000 km Mediterranean coastline with nine species considered threatened or endangered, mostly because of wetland loss and degradation. The long history of human activity and scientific investigations in the region has taught some valuable lessons. In the area of colonial waterbird biology and conservation, we have learned important lessons about the value of long-term monitoring and research on selected populations. From marking studies of Greater Flamingos (Phoenicopterus ruber roseus) and Little Egrets (Egretta garzetta) results have been used to derive useful information about metapopulation dynamics. Involvement of both African and European biologists allowed year-round Studies of these species that yielded valuable spin-offs for training in avian and wetland conservation. We have also learned the value of man-made wetlands as feeding and nesting sites for some colonial waterbirds. Careful evaluations of the habitat quality of different types of wetlands are required, as in contaminant levels such as lead shot and pesticides. Wetland conservationists have also learned from some instructive mistakes. Dam construction and agricultural incentive programs sponsored by the European Community, the World Bank, and others from the past have largely ignored impacts on wetlands and wildlife. In some areas, economic ventures such as aquaculture operations and salt mining have not involved waterbird habitat needs in their planning. Research and conservation needs include: (1) establishing regional monitoring programs and data banks for seabirds, wading birds, ducks, and geese; (2) implementing a wetland inventory for many Countries with little quantitative data on wetlands; (3) improving habitat quality assessments; (4) improving relationships with industry, the private citizenry, and government officials to further an appreciation for the value of wetlands and waterbirds; (5) enhancing training efforts, especially in underdeveloped Countries; (6) evaluating the effects of hunting and other disturbances to nesting and feeding waterbirds in different regions; (7) setting up 'sister-reserve' (twinned) sites in Europe and Africa to foster international linkages and training; and (8) fostering local-regional conservation programs to preserve reed beds, wet woodlots, and other key habitats.

Book chapter↗
USGS2008

Hydrogeology and water quality of the Leetown area, West Virginia

The U.S. Geological Survey’s Leetown Science Center and the co-located U.S. Department of Agriculture’s National Center for Cool and Cold Water Aquaculture both depend on large volumes of cold clean ground water to support research operations at their facilities. Currently, ground-water demands are provided by three springs and two standby production wells used to augment supplies during periods of low spring flow. Future expansion of research operations at the Leetown Science Center is dependent on assessing the availability and quality of water to the facilities and in locating prospective sites for additional wells to augment existing water supplies. The hydrogeology of the Leetown area, West Virginia, is a structurally complex karst aquifer. Although the aquifer is a karst system, it is not typical of most highly cavernous karst systems, but is dominated by broad areas of fractured rock drained by a relatively small number of solution conduits. Characterization of the aquifer by use of fluorometric tracer tests, a common approach in most karst terranes, therefore only partly defines the hydrogeologic setting of the area. In order to fully assess the hydrogeology and water quality in the vicinity of Leetown, a multi-disciplinary approach that included both fractured rock and karst research components was needed. The U.S. Geological Survey developed this multi-disciplinary research effort to include geologic, hydrologic, geophysical, geographic, water-quality, and microbiological investigations in order to fully characterize the hydrogeology and water quality of the Leetown area, West Virginia. Detailed geologic and karst mapping provided the framework on which hydrologic investigations were based. Fracture trace and lineament analysis helped locate potential water-bearing fractures and guided installation of monitoring wells. Monitoring wells were drilled for borehole geophysical surveys, water-quality sampling, water-level measurements, and aquifer tests to characterize the quality of water and the hydraulic properties of the aquifer. Surface geophysical surveys provided a 3-dimensional view of bedrock resistivity in order to assess geologic and lithologic controls on ground-water flow. Borehole geophysical surveys were conducted in monitoring wells to assess the storage and movement of water in subsurface fractures. Numerous single-well, multi-well, and straddle packer aquifer tests and step-drawdown tests were conducted to define the hydraulic properties of the aquifer and to assess the role of bedrock fractures and solution conduits in the flow of ground water. Water samples collected from wells and springs were analyzed to assess the current quality of ground water and provide a baseline for future assessment. Microbiological sampling of wells for indicator bacteria and human and animal DNA provided an analysis of agricultural and suburban development impacts on ground-water quality. Light detection and ranging (LiDAR) data were analyzed to develop digital elevation models (DEMs) for assessing sinkhole distribution, to provide elevation data for development of a ground-water flow model, and to assess the distribution of major fractures and faults in the Leetown area. The flow of ground water in the study area is controlled by lithology and geologic structure. Bedrock, especially low permeability units such as the shale Martinsburg Formation and the Conococheague Limestone, act as barriers to water flowing down gradient and across bedding. This retardation of cross-strike flow is especially pronounced in the Leetown area, where bedding typically dips at steep angles. Highly permeable fault and fracture zones that disrupt the rocks in cross-strike directions provide avenues through which ground water can flow laterally across or through strata of low primary permeability. Significant strike parallel thrust faults and cross-strike faults typically coincide with larger solution conduits and act as drains for the more pervasive network of interconnected diffuse fractures. Results of borehole geophysical surveys indicate that although numerous fractures may intersect a borehole, only one or two of the fractures typically transmit most of the water to a well. The diffuse-flow dominated network of fractures that provides the majority of storage occupies only a small proportion of the total aquifer volume but constitutes the majority of porosity within the aquifer. Solution conduits, while occupying a relatively small volume of the overall aquifer, are especially important because they serve as primary drains for the ground-water flow system. Surface resistivity maps and cross-sectionsshow anomalous areas of low resistivities coincident with the prevailing geologic strike at N. 20º E., with major cross-strike faults, and with major springs in the region. Transmissivity derived from straddle packer tests was highly variable, and ranged over three orders of magnitude (1.8 x 10 -6 to 5.9 x 10 -3 ft 2 /d) in diffuse-flow fractures. A similar large variability in transmissivity was documented by single- and multi-well aquifer tests conducted in conduit-flow dominated portions of the aquifer (2.0 x 10 3 to 1.4 x 10 4 ft 2 /d) in lowland areas immediately adjacent to the Leetown Science Center. A stream-gaging station installed on Hopewell Run near the point where the stream exits the Leetown watershed indicates average daily streamflow for the Hopewell Run of approximately 11.2 ft 3 /s, and ranged from a minimum of 1.80 ft 3 /s on September 28, 2005, to a maximum of 73.0 ft 3 /s on December 11, 2003. Base-flow (ground-water) discharge surveys identified numerous small seeps adjacent to streams in the area. Hydrographs of the stage of Balch Spring show rapid response to individual storms. Strong correlation of the flow of Hopewell Run and Balch Spring indicates the nearby losing stream reach is partly responsible for higher fluctuations in the stage of Balch Spring. A water budget for the study period (2003-2005), based on measured precipitation and hydrograph analyses, is expressed as Precipitation (38.60 in/yr) = Surface Runoff (1.36 in/yr) + Ground-Water Discharge (17.73 in/yr) + Evapotranspiration (24.23 in/yr) – Change in storage (4.72 in/yr). Flow of ground water through the epikarst, a shallow zone of intensely weathered rock and regolith, can be rapid (on the order of days or weeks) as flow is concentrated in solution conduits. Flow within the intermediate and deeper zones is typically much slower. Eight dye-tracer tests conducted in the Leetown area found ground-water flow patterns to be divergent, with velocities ranging from about 12.5 to 610 ft/day and a median velocity of 50 ft/day. Estimates of ground-water age in carbonate rocks in the region are on the order of 15 years in the shallower portions of the aquifer to 50 years or older for deeper portions of the aquifer. Shallow springs can have a significant component of fairly young water (< 5 years in age). Ground-water samples collected from 16 sites (12 wells and 4 springs) in the Leetown area were analyzed for more than 340 constituents. Only turbidity, indicator bacteria, and radon were typically present in concentrations exceeding U.S. Environmental Protection Agency (USEPA) drinking-water or aquatic life standards.

West Virginia↗
USGS2017

In memoriam - William Toshio (Tosh) Yasutake, 1922-2016

William Toshio (Tosh) Yasutake, 1922-2016 passed away peacefully at home on December 12, 2016, at the age of 94. He is survived by Fumi, his wife of 66 years, as well as four children and six grandchildren. With his death, the fish health community has lost an outstanding scientist as well as a kind, unassuming, and wonderful human being. Tosh was born on June 10, 1922, in Seattle, Washington, to Jack and Hide Yasutake. He was in his first year of studies at the University of Washington when Pearl Harbor was attacked by Imperial Japan on December 7, 1941. Following the attack, Tosh and his family (father, mother, sister, and two brothers) were among the 110,000–120,000 people of Japanese ancestry who were forced from their homes on the Pacific coast and incarcerated in internment camps in the interior. In June 1942, Tosh enlisted in the U.S. Army, serving as an unarmed combat medic in the famed 442nd Regimental Combat Team, the most decorated unit for its size and length of service in the history of American warfare. Wounded in October 1944 during the Vosges Mountains campaign near Bruyères, France, Tosh was evacuated and missed the ensuing battle to rescue the “Lost Battalion,” at which his replacement was killed. Tosh returned to action in Italy in February 1945 and served until the end of the war in Europe, earning both a Purple Heart and a Bronze Star for bravery. In October 2010, the Congressional Gold Medal was awarded to the 442nd Regimental Combat Team, and in 2012 the surviving members were made chevaliers of the French Légion d’Honneur for actions contributing to the liberation of France in World War II. After the war, Tosh returned to the University of Washington on the GI Bill and received a B.S. degree in zoology in 1951. In 1953 he began his research career at the U.S. Fish and Wildlife Service’s Western Fish Nutrition Laboratory at Cook, Washington, where he conducted pioneering research on nutritional fish diseases with John Halver. Tosh was one of the first to recognize hepatomas in hatchery-reared Rainbow Trout and helped to trace the disease to an aflatoxin produced by the mold Aspergillus flavis , which grew during the storage of ingredients for fish diets. In 1960, he transferred to the Western Fisheries Research Center (WFRC) in Seattle (then called the Western Fish Disease Laboratory) to start a fish pathology diagnostic laboratory. There he described the histopathology of diseases of economically important fishes, identified etiologic agents, and worked with hatchery biologists to improve the health, quality, and survival of salmonids released from federal and state hatcheries. Tosh was instrumental in recognizing that the viruses of Oregon sockeye disease and Chinook Salmon virus disease were one entity and in giving the disease its present name: infectious hematopoietic necrosis. In recognition of his pioneering research, Tosh was awarded a doctorate in fish pathology by the University of Tokyo in 1980, the first American to have been so honored. In 1983, he published his classic textbook The Microscopic Anatomy of Salmonids: An Atlas , which quickly became a standard reference work in fish pathology and is still in wide use today. For his outstanding career achievements, in 1987 Tosh received the S. F. Snieszko Distinguished Service Award, the highest honor bestowed by the American Fisheries Society’s Fish Health Section (AFS–FHS). Tosh retired in 1988 but continued his research at the WFRC as a senior scientist emeritus, providing technical assistance to federal and state agencies and to the aquaculture industry worldwide. His culminating project was to digitize his lifetime collection of photomicrographs and prepare an atlas, “Histopathology of Selected Parasitic Salmonid Diseases: A Color Atlas,” that is now posted on the Web sites of the WFRC and the AFS–FHS. Although his presence will be sorely missed, his research contributions have become part of the foundation of today’s knowledge of fisheries biology and have assured him a place in history.

Journal of Aquatic Animal Health↗
USGS2008

Fish Rhabdoviruses

Many important viral pathogens of fish are members of the family Rhabdoviridae . The viruses in this large group cause significant losses in populations of wild fish as well as among fish reared in aquaculture. Fish rhabdoviruses often have a wide host and geographic range, and infect aquatic animals in both freshwater and seawater. The fish rhabdoviruses comprise a diverse collection of isolates that can be placed in one of two quite different groups: isolates that are members of the established genus Novirhabdovirus , and those that are most similar to members of the genus Vesiculovirus . Because the diseases caused by fish rhabdoviruses are important to aquaculture, diagnostic methods for their detection and identification are well established. In addition to regulations designed to reduce the spread of fish viruses, a significant body of research has addressed methods for the control or prevention of diseases caused by fish rhabdoviruses, including vaccination. The number of reported fish rhabdoviruses continues to grow as a result of the expansion of aquaculture, the increase in global trade, the development of improved diagnostic methods, and heightened surveillance activities. Fish rhabdoviruses serve as useful components of model systems to study vertebrate virus disease, epidemiology, and immunology.

Book chapter↗
USGS2025

Local perceptions of marine conservation aquaculture for the restoration of native Atlantic salmon (Salmo salar) in Downeast, Maine

The entities responsible for the management of the endangered Gulf of Maine Distinct Population Segment of Atlantic salmon ( Salmo salar ) have partnered with a commercial aquaculture company to apply a novel conservation aquaculture program. This effort marks a major shift in management and has garnered mixed public reactions. Recent expansion of aquaculture in Maine has been a point of controversy as people and systems grapple with the social, environmental, and legal aspects of this burgeoning industry. Still, the use of aquaculture for conservation has shown some promise. In 2021, a questionnaire was administered to 850 households (response rate 27 %) in Maine via the Drop-off and Pick-up method. We examined differences and similarities in attitudes, beliefs, and knowledge about Atlantic salmon, hatcheries, and aquaculture between property owners in the town where the proposed net pens would be located (Cutler; n=73), and those in neighboring towns (n=152). The Potential for Conflict Index (PCI 2 ) was used to examine differences between the groups. Both groups held similar positive attitudes toward Atlantic salmon, endangered species conservation, freshwater hatcheries, and both commercial and conservation aquaculture. Both groups believe that “ Atlantic salmon should be protected, ” and that freshwater hatcheries and marine conservation aquaculture “ should be used for conservation. ” However, Cutler residents had less consensus and supported the use of freshwater hatcheries and marine conservation aquaculture less than other respondents. Community concerns have stalled efforts to move the project forward. Our research indicates there are several social concepts which may help to explain localized opposition to the project.

Maine↗
USGS2025

Detection and genetic characterization of red-spotted grouper nervous necrosis virus and a novel genotype of nervous necrosis virus in black sea bass from the U.S. Atlantic coast

Nervous necrosis virus (NNV) causes a neurologic disease in a wide range of marine fish and poses serious disease risks to marine aquaculture worldwide. Little is known about the presence of NNV along the Atlantic coast of the United States, aside from the presence of barfin flounder nervous necrosis virus (BFNNV) in coldwater species in the northern part of this range. Herein we conducted surveillance for NNV from 2020 to 2022 in the mid-Atlantic region of the United States in black sea bass Centropristis striata , a serranid fish that is found throughout the eastern U.S. coast. Molecular detection methods have identified and characterized red-spotted grouper nervous necrosis virus (RGNNV) sequences at low prevalence throughout the years. Further, in 2022, a higher prevalence of a novel NNV genotype, tentatively named black sea bass nervous necrosis virus (BSBNNV), was characterized for the first time. Though virus isolation was unsuccessful, this study was the first to genetically identify NNV in this region and in this species. These findings highlight the need for further research on NNV to understand epidemiology and virulence in the context of marine fisheries and an emerging marine aquaculture industry in the United States.

New Jersey↗
USGS2022

Science and innovation for battling invasive carp

The U.S. Geological Survey (USGS) is the Federal Government’s independent research agency that conducts research to inform management of invasive species. Bighead, black, grass, and silver carp, which are native to China, were originally stocked in aquaculture facilities to control algae, snails, and vegetation. These species have invaded the Mississippi River and are now established throughout the lower and middle Mississippi River Basins and some of its large tributaries where they damage ecosystems and harm economies. A reproducing population of grass carp in Lake Erie is a risk to the $7 billion Great Lakes fishery. The USGS is leading research efforts on risk assessment and on early detection of new invasions. The USGS is also developing and evaluating harvest methods, barriers and deterrents, and baits/attractants to provide Federal and State management agencies the tools needed to manage and reduce populations of these species.

Alabama, Arkansas, Illinois, Indiana, Iowa, Kansas↗