Search

Trawl catches indicated diel migratory activities by young-of-the-year alewife Alosa pseudoharengus, American shad A. sapidissima, and blueback herring A. aestivalis in Virginia rivers. Bottom catches were significantly greater during day than at night; conversely, surface catches were significantly greater at night than during day. Spatial separation of alewife and blueback herring stocks, which could reduce feeding competition, also was indicated. Surface pushnet catches of blueback herring were associated with a sky-opacity index, suggesting that this species (or its prey) is negatively phototropic. The influence of light on distributions of juvenile Alosa should be taken into account when sampling location, time, and gear are chosen for stock-assessment programs.

Results of an analysis of abyssal benthic megafauna based upon review of nearly 250 hours of videotape and 2149 bottom photographs are presented, and the utility and limitations of such analyses in deep sea biological studies are discussed. The images were acquired at depths of 4,400-4,800 metres during a resource assessment cruise aboard the RV PROSPECTOR using a unique deep-towed television-telemetry system coupled with 35mm photography. The data review was carried out in support of National Oceanic and Atmospheric Administration (NOAA) efforts to provide adequate environmental baseline information before industrial exploitation of nodule deposits and concurrent monitoring begin.

Young-of-the-year alewife, American shad, blueback herring, and striped bass were analyzed for Kepone contamination. Samples were collected from the Potomac, Rappahannock, Pamunkey, Mattaponi, Chickahominy, and James rivers during the period 1977–79. Concentrations of Kepone ≥0.3 ppm occurred in all four species collected in the James River nursery zone between km 65 and 120, and in the lower Chickahominy River. Concentrations of Kepone