Publications

The ability to predict subsequent landings of striped bass Morone saxatilis from the indices of abundance of juveniles (young of the year) determined annually by the Maryland Department of Natural Resources was evaluated by multiple‐regression techniques. About 57% of the variation in reported landings could be accounted for by the juvenile indices 2, 3, 4, and 5 years prior to the year...

No abstract available.

Phytoplankton of the Potomac River and Estuary were counted and identified to the generic level. Double-blind precision tests for an individual counter yielded a standard deviation that was * 10 percent of the mean. Differences between three counters exceeded * 10 percent, and a curve could be fit to calibration counts to yield correlation coefficients of 0.70 to 0.86 between counters...

No abstract available.

A one-dimensional unsteady flow model has been applied to the tidal Potomac River, including its major tributaries and marginal embayments, between Washington, D. C. and Indian Head, Md. The computer model has been calibrated to simulate the combined effects of tide, freshwater inflows, and wind conditions governing flow in the system of channels. The comprehensive flow data provided by...

No abstract available.

Field and laboratory evaluations were made of a simple, inexpensive diffusion-controlled sampler with ports on two sides at each interval which incorporates 0.2-??m polycarbonate membrane to filter samples in situ. Monovalent and divalent ions reached 90% of equilibrium between sampler contents and the external solution within 3 and 6 hours, respectively. Sediment interstitial water...

The yield of striped bass (Morone saxatilis) in biomass and numbers was estimated for constant recruitment of young fish into the population on the basis of vital statistics of the Maryland stock. Separate computations were performed for males, females, and sexes combined. Yield in biomass per individual entering the population was highest when the minimum legal length was in the range...

Bald eagle (Haliaeetus leucocephalus) eggs were collected in 14 States in 1969–79 and analyzed for organochlorine pesticides, polychlorobiphenyls, and mercury. Moderate shell thinning occurred in eggs from several areas. Eggs from the Chesapeake Bay area contained the highest residue levels of most organochlorines. DDE was detected in all eggs; other organochlorines were detected less...

Feeding flights of Snowy Egrets (Egretta thula), Tricolored Herons (E. tricolor), Little Blue Herons (E. caerulea), and Cattle Egrets (Bubulcus ibis) were monitored at a small nesting colony near Chincoteague, Virginia during late May and June 1979. All four species varied their flight directions over a series of days. Cattle Egrets oriented in a different direction (toward uplands) from...

No abstract available.

The U.S. Geological Survey began a 5-year interdisciplinary study of the tidal Potomac River and Estuary in October of 1977. The objectives of the study are: (1) to provide a basic understanding of physical, chemical, and biological processes; (2) to develop flow and transport models to predict the movement and fate of nutrients and algaes and (3) to develop efficient techniques for the...