The prevalence of stormwater wet detention ponds in coastal South Carolina may have significant influences on the biogeochemical linkages between terrestrial nutrient runoff and organic matter production and fate in the coastal zone. That many of these ponds are high in algal biomass suggests that organic matter production within these ponds can be substantial. Quantifying the magnitude and fate of this organic matter is critical to determining the influence of stormwater ponds on coastal water quality impairment. A key issue in this regard is the effects that various land uses and current design criteria for stormwater ponds have on pond Net Ecosystem Production (NEP) and bioavailability of pond-derived organic carbon and nitrogen.
The specific objectives of this study are to (1) quantify rates of NEP across 30 individual residential and golf course stormwater ponds and determine relationship(s) between nutrient conditions and NEP in these ponds, (2) quantify degradation kinetics and bioavailability of pond-derived dissolved organic carbon (DOC) and dissolved organic nitrogen (DON), the extent to which these vary as a function of pond NEP, and the effects that pond-derived DON has on primary productivity and phytoplankton species composition of coastal marine ecosystems, (3) determine the role that stormwater pond size and design attributes have on nutrient – NEP relationship(s) and DOC/DON production and bioavailability, and (4) compare and contrast temporal dynamics of pond productivity, internal nitrogen transformations, and DOC/DON production and bioavailability in response to storm events among a subset of ponds of varying morphometry and design criteria.