Groundwater discharge and associated nutrient fluxes to the Delaware Bay at Cape Henlopen, Delaware

Groundwater discharge is a source of both fresh water and dissolved nutrients (nitrogen, phosphorus, and silica) to coastal waters. The fresh groundwater frequently carries higher nutrient concentrations than the receiving coastal waters and thus knowledge of the fluxes of nutrients from the fresh groundwater is important in defining mass balances in the coastal zone. This study focused on quantifying the total groundwater discharge at low tide from a seepage site at Cape Henlopen, Delaware, and on determining the nutrient fluxes from the groundwater to the adjacent Delaware Bay. The groundwater discharging from the beachface at Cape Henlopen is a mixture of "new" fresh groundwater and "recycled" estuarine water and thus should have characteristics intermediate to the two end-member waters, however, diagenetic reactions occurring within the beachface were found to modify the fluxes of some of the nutrient species. (Abstract shortened by UMI.)...