Spatial distribution of benthic-pelagic coupling

Coastal estuaries and bays are sites of strong environmental gradients caused by tides, winds and river flow. Bottom sediments are a manifestation of this variation, with bottom habitat (sand, mud, plants) reflecting the energy of the environment and development of animal communities. The shallow well-mixed water column insures that the bottom influences overlying waters by resuspension of sediments and organic debris, and release of nutrients from decomposition. Material produced in the water column (phytoplankton) sinks to the bottom where it fuels these processes. The rate at which material is cycled between the bottom, water column, and coastal ocean determines how estuaries deal with pollution, excess nutrients, and a variety of stresses. Although there is some understanding of the range of different habitat types, their relative importance is not well known. For example, it is expected that decomposition will be greater in organic-rich mud than in clean sand, but this level of spatial resolution is rarely included in the models that are used to make predictions about the functioning of coastal ecosystems. The proposed research will document variation in coastal habitats as well as the rate at which physical exchange, decomposition, and primary production (plants, microalgae) occur in these habitats. I will use remote detection techniques such as acoustic seabed mapping to define habitat variation. A series of detailed measurements on decomposition, plant growth, and other processes will be measured in multiple locations, allowing a match between environmental conditions and their role in ecosystem functioning. This information will then be input to improved ecosystem models to allow greater capability in prediction of effects from nutrient loading, resource extraction, fisheries, commercial development, and climate change.