HR: 10:45h
AN: NB52F-02    [Abstracts]
TI: Linking Watershed Land Cover to Ecological Indicators in Streams and Subestuaries of Chesapeake Bay
AU: * King, R S
EM: Ryan_S_King@baylor.edu
AF: Center for Reservoir and Aquatic Systems Research, Department of Biology, Baylor University, One Bear Place #97388, Waco, TX 76798 United States
AU: Whigham, D F
EM: whighamd@si.edu
AF: Smithsonian Environmental Research Center, P.O. Box 28, Edgewater, MD 21037 United States
AU: DeLuca, W V
EM: delucaw@si.edu
AF: Smithsonian Environmental Research Center, P.O. Box 28, Edgewater, MD 21037 United States
AU: Baker, M E
EM: bakerm@si.edu
AF: Smithsonian Environmental Research Center, P.O. Box 28, Edgewater, MD 21037 United States
AU: Hines, A H
EM: hinesa@si.edu
AF: Smithsonian Environmental Research Center, P.O. Box 28, Edgewater, MD 21037 United States
AU: Marra, P P
EM: marrap@si.edu
AF: Smithsonian Environmental Research Center, P.O. Box 28, Edgewater, MD 21037 United States
AU: Weller, D E
EM: wellerd@si.edu
AF: Smithsonian Environmental Research Center, P.O. Box 28, Edgewater, MD 21037 United States
AU: Gallegos, C A
EM: gallegosc@si.edu
AF: Smithsonian Environmental Research Center, P.O. Box 28, Edgewater, MD 21037 United States
AU: Jordan, T E
EM: jordant@si.edu
AF: Smithsonian Environmental Research Center, P.O. Box 28, Edgewater, MD 21037 United States
AB: Estuaries are dynamic, hydrologically open ecosystems. Consequently, it is difficult to identify linkages between the ecological health of estuaries and their watersheds. In 2002 and 2003, we sampled streams and subestuaries of 31 subwatersheds of Chesapeake Bay that spanned gradients in land use ranging from largely forested to highly developed or agricultural. Ecological indicators included water quality, wetland vegetation, benthic macroinvertebrate, bird, and fish assemblages, contaminants in fish, and estuarine optical properties. We observed a consistent linkage between the amount and spatial proximity of developed land and degraded ecological condition in both streams and subestuaries, with many indicators exhibiting threshold responses at similar levels of development in both years. The effect of agriculture was unclear for most indicators except stream nutrient concentrations, which increased with increasing percentage of cropland in watersheds. However, in 2003 (a wet year), markedly higher concentrations of nutrients were observed in agricultural subestuaries than in 2002, suggesting an interaction between watershed landuse and interannual hydrologic flux on estuarine nutrients. Overall, the majority of estuarine indicators responded negatively to development and less to agricultural land uses. Given the trend of urbanization of agricultural lands in coastal areas, our results have important management implications for coastal watersheds.
DE: 9810 New fields (not classifiable under other headings)
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly