Aquatic Sciences Meeting, Albuquerque 2001

CS20 Microbial Dynamics

Date: Friday, February 16, 2001, Time: 10:00:00 AM

Location: Ruidoso/Pecos

Apple, J, K, University of Maryland Center for Environmental Science Horn Point Laboratory, Cambridge MD 21613, USA, japple@hpl.umces.edu

del Giorgio, P, A, University of Maryland Center for Environmental Science Horn Point Laboratory, Cambridge MD 21613, USA, delgior@hpl.umces.edu

THE EFFECTS OF ANTHROPOGENIC NUTRIENT LOADING ON BACTERIOPLANKTON COMMUNITY METABOLISM OF ESTUARINE WATERS

Although anthropogenic nutrient loading has been unequivocally linked to increased primary production in aquatic systems, the direct impact of nutrient inputs on heterotrophic bacterial communities remains a poorly understood component of the eutrophication process. The effects of anthropogenic nutrient inputs on bacterioplankton metabolism were studied in Monie Bay, a small tidally influenced estuarine sub-system of the Chesapeake Bay, USA. Two marsh creeks impacted by agricultural nutrient inputs and a third unimpacted creek were sampled monthly between April and September and compared to the open bay waters. Ambient nutrient concentrations differed systematically among creeks and were linked to source proximity and to local fertilizer application schedules. Bacterial production, single-cell activity, and bacterial growth efficiency also varied systematically among the creeks and were related to variations in ambient nutrient concentrations. Bacterioplankton communities responded differently to nutrient enrichment, and the relationship between production and single-cell activity differed markedly among creeks. These differences may be attributed to variations in the watershed characteristics of each creek, which may in turn influence the composition of the bacterioplankton assemblage and their response to nutrient inputs.

Return to This Session's Schedule · Complete Session Listing ·

Aquatic Sciences Meeting, Albuquerque 2001

Quicklinks