Publications

No abstract available at this time

No abstract available.

Determining factors that limit winter survival of waterfowl is necessary to develop effective management plans. We radiomarked immature and adult female mallards (Anas platyrhynchos) after the 1988 and 1989 hunting seasons in eastcentral Arkansas to test whether natural mortality sources and habitat conditions during late winter limit seasonal survival. We used data from 92 females to...

Aeromonas salmonicida was isolated from paddlefish (Polyodon spathula) mortalities collected during an epizootic of furunculosis at the Spring River State Hatchery, Arkansas (USA), in 1992. Isolates of the bacterium were obtained from culture of gill and kidney tissue. This is the first epizootic of bacterial etiology to be reported in paddlefish.

During the 1988 and 1989 growing seasons, dissolved gas pressures were measured in 0·04 ha to 0·06 ha earthen ponds (n = 17) used to produce channel catfish or bluegill sunfish, both with and without supplemental aeration. Surface waters in early morning hours (0630 to 0830 h) were typically saturated with nitrogen (N2) and argon (Ar), undersaturated with dissolved oxygen (DO), and...

An 18 month simulation of circulation was conducted in Massachusetts Bay, a roughly 35 m deep, 100??50 km embayment on the northeastern shelf of the United States. Using a variant of the Blumberg-Mellor (1987) model, it was found that a continuous 18 month run was only possible if the velocity field was Shapiro filtered to remove two grid length energy that developed along the open...

New seismic data from marine air-gun and Vibroseis profiles in Lake Ontario and Lake Erie provide images of subhorizontal Phanerozoic sediments underlain by a remarkable series of easterly dipping reflections that extends from the crystalline basement to the lower crust. These reflections are interpreted as structural features of crustal-scale subdivisions within the Grenville Orogen...

No abstract available.

A map showing ground-water levels in Buckingham and Wrightstown Townships, Bucks County, Pennsylvania, was constructed from water levels measured in 251 wells and from 3 reported elevations of quarry sumps from June 1992 through January 1993. Observed water-level altitudes range from 459 feet above sea level along Burnt House Hill Road, south- west of Mechanicsville, to 10 feet above sea...

This U.S. Geological Survey Open-File Report [extract] contains a listing of publications authored or co-authored by members of the Branch of Atlantic Marine Geology and published in calendar year 1993. The Branch conducts a broad geologic and geophysical research and mapping program, primarily along the U.S. Atlantic Margin, in the Great Lakes, the Gulf of Mexico, the Caribbean and...

Two episodes of meltwater influx from glacial Lake Agassiz are recorded as prominent sedimentologic, isotopic, magnetic, and faunal signatures in southern Lake Michigan profundal sediments. As a tributary to the main path of eastward Lake Agassiz flow, southern Lake Michigan recorded only the largest, catastrophic discharges. The distinctive Wilmette Bed, a massive gray mud that...

Streamlined, oval-shaped, oriented topographic highs in Massachusetts Bay are identified as the erosional remnants of drumlins. The topographic highs correlate with outlines of lag gravel deposits on the sea floor and both the highs and lag gravel seafloor footprint have a distinct east-southeast long axis trend. This trend is similar to the preferred orientation of the long axes of...