Impact of Aquatic Vegetation on Water Quality of the Delaware River Estuary

The objective of this study was to evaluate the impact of aquatic vegetation, emergent and submergent, on water quality of designated sections of the tidal freshwater Delaware Estuary. The breadth of the survey region encompasses two study segments within the tidal freshwater estuary from the head of tide near Trenton, NJ (Morrisville-Trenton Bridge) to just downstream of the confluence with Chester Creek, PA (Commodore Barry Bridge). Specific tasks that were investigated for the two study areas include: (1) estimate aerial extent of emergent aquatic vegetation and the extent of each of the dominant species; (2) determine the biomass of the dominant species and productivity; (3) estimate the daily-average, net dissolved oxygen (DO), phosphorus and nitrogen fluxes within the water column, per estuary river-mile and over the range of the study time period based on a comprehensive literature survey; and (4) evaluate the potential impact of submerged aquatic vegetation on DO, phosphorus, and nitrogen net fluxes within the water column. This report also includes a plan for potential future evaluation of emergent and submerged aquatic vegetation beds, including periphyton and epiphytes for the entire estuary, in terms of their ecological importance upon the tidal estuary in relation to water quality, productivity, and habitat.Final Report 98-5