Owens, M. S. UMCES, Horn Point Laboratory, owens@hpl.umces.edu
Cornwell, J. S. UMCES, Horn Point Laboratory, cornwell@hpl.umces.edu
Kana, T. M. UMCES, Horn Point Laboratory, kana@hpl.umces.edu
Bryner, J. UMCES, Horn Point Laboratory, jbryner@hpl.umces.edu
Haberkern, E. K. UMCES, Horn Point Laboratory, erik@hpl.umces.edu

 
DO TIDAL FRESHWATER AND OLIGOHALINE HABITATS IMPROVE DOWNSTREAM WATER QUALITY: EXAMPLES FROM A CHESAPEAKE BAY SUBESTUARY
 
The eutrophication of the Chesapeake Bay has been a concern of researchers and managers for a considerable period of time, with excessive nutrient inputs leading to loss of benthic primary production and bottom water anoxia in the main stem of the bay. The tidal freshwater and oligohaline reaches of Chesapeake Bay tributaries are often the first part of the estuary to receive nitrogen from point sources and from agricultural runoff. High inputs and concentrations of sediment and nitrate characterize these environments. While high turbidity limits the utilization of nitrogen by phytoplankton, nitrogen may be lost to sediment bacterial processes and to utilization and burial in the extensive tidal marsh communities found in these environments. Monthly measurements of sediment denitrification at four sites across the salinity gradient in the Choptank River subestuary were carried out in 1998. These data show considerable spatial and seasonal variability, largely related to temperature, salinity and nitrate concentration. High rates of marsh N burial were estimated from dated sediment cores. A first-order analysis of both sediment denitrification and marsh N burial rates relative to N input rates suggest that these processes can greatly alter the nitrogen balance in the subestuary.
 
Day: Tuesday, Feb. 2
Time: Poster
Location: Sweeney Center
 
Code: SS06TU0780S