Publications

The U.S. Geological Survey is conducting a water quality study as part of the nationally implemented Rural Clean Water Program in the headwaters of the Conestoga River, Pennsylvania. The study, which began in 1982, was designed to determine the effect of agricultural best management practices on surface--and groundwater quality. The study was concentrated in four areas within the...

The characteristics and distributions of near-surface bottom sediments and of nutrients in the sediments provide information on modern sediment and nutrient sources, sedimentation environments, and geochemical reactions in the tidal Potomac system, Maryland and Virginia. This information is fundamental to an improved understanding of sedimentation and eutrophication problems in the tidal...

The Potomac River at Chain Bridge is the major riverine source of dissolved silica (DSi) to the tidal Potomac River and Estuary. DSi concentrations at Chain Bridge are positively correlated with river discharge; river discharge is an important factor controlling rates of supply, dilution, and residence time. When river flow is high, the longitudinal DSi distribution is conservative. When...

No abstract available.

In situ and mobile on-site striped bass prolarval and yearling survival studies were conducted in the Choptank River and in the Chesapeake and Delaware (C & D) Canal area of the Upper Chesapeake Bay. Extensive chemical analyses of both organic and inorganic contaminants in the habitat water were performed and water quality parameters were monitored during these experiments. Surviving...

No abstract available.

The distribution and abundance of phytoplankton in the fresh, tidal Potomac River, Md., was different during 1979-81 from that observed in the 1960's and 1970's. Concentrations of phytoplankton in the 1960's and 1970's reached maximum attainable levels that were limited only by self-shading. A sag in phytoplankton abundance, apparent during the summers of 1980 and 1981 between Rosier...

The mouth of Chesapeake Bay contains a distinctive shoal complex and related deposits that result from the complex interaction of three different processes: (1) progradation of a barrier spit at the southern end of the Delmarva Peninsula, (2) strong, reversing tidal currents that transport and rework sediment brought to the bay mouth from the north, and (3) landward (bayward) net non...

No abstract available.

No abstract available.

Baltic clams (Macoma balthica) were the predominant food items of 323 canvasbacks (Aythya valisineria) collected throughout Chesapeake Bay during 1970–1979. Natural vegetation constituted 4% of the food volume. Widgeongrass (Ruppia maritima) and redhead grass (Potamogeton perfoliatus) constituted the greatest percent volume and frequency of occurrence among the plant species, whereas...

A three-year study of seasonal variation in water-column and sediment nitrogen species was conducted in the transition zone of the Potomac River 35 m from the Virginia shore at a site with an average water-column depth of approximately 1 m over sandy sediment. A diffusion-controlled sampler was used to collect water samples from the water column, at the interface between the water column...