This proposal brings together a highly interdisciplinary group of PIs to study the processing of algal carbon and nitrogen in sediments. It is hypothesized that sediment reworking under three different mixing regimes - bioturbated, unmixed and episodically mixed - will have a direct effect on organic matter processing. State of the art sediment geochemical techniques will be used to characterize the sediments and a large suite of biogeochemical tracers will be monitored in sediment mesocosms to which dual labeled (13C and 15N) algal material is added as a novel tracer of organic cycling. Microbial community structure will also be followed using molecular biological techniques. Oscillation of reactants between oxic and anoxic conditions is thought to be critical for organic matter degradation and nutrient cycling. These oscillations can be triggered by natural events (storms, for example) and man made impacts (eutrophication, for example). The results of the work will therefore have broad impact on our understanding of the health of the coastal ocean.
This proposal was part of the Environmental Geochemistry and Biogeochemistry program. It will be jointly funded by the Division of Ocean Sciences, Division of Chemical and Transport Systems, and the Division of Earth Sciences.
