The Retention of Nutrients (C, N, P), Heavy Metals (Mn, Cd, Pb, Cu), and Petroleum Hydrocarbons in Narragansett Bay

Abstract

Nixon, S.W., Hunt, C.D. and Nowicki, R.L., 1986. The retention of nutrients (C, N, P), heavy metals (Mn, Cd, Pb, Cu), and petroleum hydrocarbons in Narragansett Bay. In: P. Lasserre and J.M. Martin (eds), Riogeochemical Processes at the Land-Sea Boundary. Elsevier, Amsterdam. Various workers have assembled relatively complete assessments of the annual input h e major biological nutrients (C, N, P), certain heavy metals (Mn, Cd, Pb, Cu), and petroleum hydrocarbons to Narragansett Bay. Other studies have developed inventories h e amounts of these materials in the sediments of the Bay. We have brought these data together with information on sediment accumulation ratesin the Bay to determine degree to which this one estuary serves as a sink for different types of materials in their passage between land and the coastal ocean. It appears that Narragansett Bay retains less than 5% of the nutrients, less than 10% of the Mn, and perhaps 15-30% of the Cd that is input to the system each year. The removal of Cu (70-95%) and Pb (80-100%) i s much more effective. Somewhere between 25–65% of the petroleum hydrocarbons entering the Bay remain in the sediments. These estimates are in agreement with the behavior of the different materials in sediment-water flux measurements and in experiments using the large MERL mesocosms.