Publications

Perkinsus marinus, the cause of serious losses of the eastern oyster Crassostrea virginica, secretes extracellular proteins (ECP) in culture (in vitro) including serine proteases. The production of similar ECP in the eastern oyster (in vivo) and their role in pathogenicity, however, remain to be elucidated. The induction and dissemination of these proteins within infected eastern oysters...

SEABOSS has proved to be a valuable addition to the USGS data-acquisition and processing field program. It has allowed researchers to collect high-quality images and seabed samples in a timely manner. It is a simple, dependable and trouble-free system with a track record of over 3,000 deployments. When used as part of the USGS seafloor mapping acquisition, processing, and ground-truth...

Food web studies often ignore details of temporal, spatial, and intrapopulation dietary variation in top-level consumers. In this study, intrapopulation dietary variation of a dominant carnivore, the Laughing Gull (Larus atricilla), was examined using carbon, nitrogen, and sulfur isotope analysis of gull tissues as well as their prey (fish, invertebrates, and insects) from the Virginia...

No abstract available.

No abstract available.

This preliminary experimental lithogeochemical map shows the distribution of rock types in the Virginia and Maryland parts of the Chesapeake Bay watershed. The map was produced digitally by classifying geologic-map units according to composition, mineralogy, and texture; rather than by age and stratigraphic relationships as shown on traditional geologic maps. This map differs from most...

Beginning in 1995, the USGS, in cooperation with the U.S Army Corps of Engineers (USACE), New York District, began a program to generate reconnaissance maps of the sea floor offshore of the New York-New Jersey metropolitan area, one of the most populated coastal regions of the United States. The goal of this mapping program is to provide a regional synthesis of the sea-floor environment...

Total coliform and Escherichia coli (E. coli) bacteria were analyzed in ground water sampled from 78 private household-supply wells as part of a study by the U.S. Geological Survey in cooperation with the Pennsylvania Department of Environmental Protection to evaluate the relation between well construction characteristics and the occurrence of bacteria in ground water. Sampling was done...

In October 1998, a chemical synoptic survey was conducted by the U.S. Geological Survey, in cooperation with the U.S. Department of Energy, National Energy Technology Laboratory, in the Lower Youghiogheny River Basin in Pennsylvania to give a snapshot of present (1998) water quality during low-flow conditions. Water samples from 38 sites—12 mainstem sites, 22 tributaries, and 4 mine...

Atlantic salmon (n = 1682) from 27 anadromous river populations and two nonanadromous strains ranging from south-central Maine, USA to northern Spain were genotyped at 12 microsatellite DNA loci. This suite of moderate to highly polymorphic loci revealed 266 alleles (5–37/locus) range-wide. Statistically significant allelic and genotypic heterogeneity was observed across loci between all...

Overharvest and habitat alteration have led to a collapse of most commercial Atlantic sturgeon(Acipenser oxyrinchus oxyrinchus)fisheries while pushing the species to rarity or extirpation in most of its historical range. A biologically sound conservation program for this species requires knowledge of its genetic diversity and of the evolutionary relationships among geographic populations...

The hormones responsible for the regulation of the teleostean gill Na+–K+–2Cl− cotransporter have not been elucidated. With Western blotting and immunocytochemistry, Na+–K+–2Cl− cotransporter abundance and localization were examined in the gills of Atlantic salmon (Salmo salar) following 2-week treatment with growth hormone (GH; 5.0 μg · g−1), cortisol (50 μg · g−1), and both hormones in