Aquatic Sciences Meeting, Albuquerque 2001

PC09 River and Margin Biogeochemistry

Date: Wednesday, February 14, 2001

Location: Southwest Hall

Eddins, S, N, University of South Carolina, Columbia, USA, nikolova@geol.sc.edu

Williams, D, F, University of South Carolina, Columbia, USA, doug.williams@schc.sc.edu

TERRESTRIAL CONTRIBUTIONS TO PARTICULATE ORGANIC CARBON AT THE AIR-SEA INTERFACE, WINYAH BAY, SOUTH CAROLINA

Using the isotopic and elemental composition of particulate organic carbon (POC) and chlorophyll concentrations, potential carbon sources at the air-sea interface of Winyah Bay, South Carolina, were assessed. Seasonal ebb-tidal samples were collected along an estuarine longitudinal transect. POC:Chl-a ratios higher than 200, measured in 95% of the samples, indicated detritally dominated POC. The 2.5 permil difference between delta C-13 of POC at the air-sea interface (-26.3+/-1.2 permil, averaged over all stations and seasons) and that of common C-3 plants from the area (-28.8+/-1.3 permil) suggested predominantly C-3 derived POC relative to that from C-4 and phytoplankton. Seasonal average delta C-13 at the interface ranged from –27.1 to –25.1 permil, while spatial averages ranged from –27.9 to –25.4. A mixing model using isotopic, POC and chlorophyll data assessed C-3, C-4 and phytoplankton contributions. More than 70% of POC was of C-3 plant origin suggesting a river-dominated air-sea interface in Winyah Bay. The estimate error was less than 10%.

This Session Listing

Aquatic Sciences Meeting, Albuquerque 2001

Quicklinks