GCRC Project Summary |
Rates and Controls of Sediment Processes Regulating Nutrient Regeneration/Burial in the Satilla River Estuary
PIs: Joel E. Kostka*, Clark R. Alexander and Richard A. Jahnke (Skidaway Inst of Oceanography, Savannah, Georgia, USA) *Currently at Florida State Univ.
Support: Georgia Sea Grant College Program (project R/WQ-4).
Timeframe: 3/1/98 - 2/28/00 (complete)
Project Objectives:
- To directly measure rates of nutrient regeneration and burial from a range of sediment types (and salinity conditions) to the water column of the Satilla River and an adjacent tidal creek
- To characterize the porewater/solid phase geochemistry of a range of sediment types in the Satilla River channel, in an adjacent tidal creek, and in a fringing marsh
- To utilize
sediment incubations to elucidate rates and pathways of the dominant microbial/geochemical
processes controlling nutrient flux in sediments of the Satilla river estuary.
Findings:
- Porewater nutrient distributions correlated with sediment grain size (sand or silt), indicating that advection is likely to be an important nutrient exchange mechanism.
- Benthic flux chamber deployments (2 in the fall and 4 in the spring) indicate drastic changes in nutrient fluxes, with much higher fluxes observed in the fall.
Publications:
J.E. Kostka, B. Gribsholt, E. Petrie, D. Dalton, H. Skelton, and E. Kristensen. 2001. The rates and pathways of carbon oxidation in bioturbated saltmarsh sediments. Submitted to Limnology & Oceanography.
J.E. Kostka, A. Roychoudhury, P. Van Cappellen. 2001. Rates and controls of anaerobic microbial respiration across spatial and temporal gradients in saltmarsh sediments. Submitted to Biogeochemistry.
R.A. Jahnke, C.R. Alexander, and J.E. Kostka. 2001. Advective pore water input of nutrients to the Satilla River estuary, Georgia, USA. In preparation.
J.E. Kostka, R.A. Jahnke, and C.R. Alexander. 2001. Biogeochemical controls of nutrient fluxes in riverine sediments of the Satilla estuary, Georgia, USA. In preparation.