Submersed aquatic vegetation in the tidal Potomac River and Estuary of Maryland, Virginia and the District of Columbia; Hydrologic data report, May, 1978 to November, 1981

Abstract

As part of a comprehensive interdisciplinary study of the tidal Potomac River and Estuary, the U.S. Geological Survey studied the distribution and abundance of submersed aquatic vegetation from 1978 to 1981. Sites were chosen throughout the tidal river and estuary. The plant species were identified; distribution and abundance of submersed aquatic vegetation were determined at the sites; and volumes, biomass-volume equivalents, and representative stem lengths were measured. Substrate types were identified, and particle size distribution, bottom nutrients, organic carbon, and heavy metals were measured at numerous sites. Water quality parameters that were measured included temperature, conductivity, salinity, secchi depth, photosynthetically active radiation, pH, chlorophyll a., nutrient concentrations, and epiphyte biomass. Experiments were performed in the field and in the laboratory to evaluate factors that would potentially affect distribution and abundance of aquatic macrophytes. For example, plants were suspended in cages and planted in exclosures, and transplant success was determined.