Porewater nutrients, dissolved organics, redox species, and gasses in estuarine intertidal sediments at sites on Sapelo Island and near the Satilla River from Fall 2000 through Fall 2002

Seasonal patterns of estuarine creek-bank sediment porewater nutrients, dissolved organics, redox species and gasses were investigated at several sites on Sapelo Island and the Satilla River in coastal Georgia. Porewater ammonium, nitrate+nitrite, phosphate, silica, dissolved organic carbon, nitrogen and phosphorus, reduced iron and manganese, chloride, sulfate, hydrogen sulfide, pH, dissolved inorganic carbon, methane and nitrogen gas were measured at centimeter scale resolution depth profiles with the use of porewater equilibration meters. Several relatively pristine sites on Sapelo Island (Moses Hammock, Dean Creek and Marine Institute), a site slightly impacted by development (White Oak Creek) and a presumably heavily impacted site (Dover Bluff) show different levels and patterns of several porewater constituents.