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BACTERIOPLANKTON DYNAMICS IN PENSACOLA BAY, FL, USA: ROLE OF PHYTOPLANKTON AND DETRIAL CARBON SOURCES
Murrell, M C. BACTERIOPLANKTON DYNAMICS IN PENSACOLA BAY, FL, USA: ROLE OF PHYTOPLANKTON AND DETRIAL CARBON SOURCES. Presented at Estuarine Odyssey, St. Pete Beach, FL, 4-8 Nov., 2001.
Bacterioplankton Dynamics in Pensacola Bay, FL, USA: Role of Phytoplankton and Detrital Carbon Sources (Abstract). To be presented at the16th Biennial Conference of the Estuarine Research Foundation, ERF 2001: An Estuarine Odyssey, 4-8 November 2001, St. Pete Beach, FL. 1 p. (ERL,GB R851).
Bacterioplankton dynamics were studied in Pensacola Bay, Florida, USA to examine the relative role of riverine detritus versus phytoplankton as substrate fueling bacterioplankton metabolism. Monthly samples were collected at five sites along the axis of the estuary spanning the salinity gradient. Bacterioplankton parameters included biomass via direct counts, production via incorporation of radio-labeled L-leucine, and ectoenzyme activities of aminopeptidase, alpha-glucosidase and beta-glucosidase enzymes using methylumbelliferyl
substrate analogs. Ancillary data included chlorophyll a nutrients, PC/PN, and DOC. Seasonally, most metabolic rates showed strong temperature-driven variability, peaking at all stations during the July-August period. An exception was aminopeptidase activity, which peaked during the spring diatom bloom in March. Spatially, beta-glucosidase activities peaked at the uppermost site in the Escambia River, suggesting increased metabolism of cellulose and other beta-linked polysaccharides, and consistent with the distribution of bulk DOC. However, bacterioplankton biomass, L-leucine incorporation, and alpha-glucosidase measures
peaked downstream of this site at mouth of the Escambia River, coinciding with maximal chlorophyll concentrations. This overall pattern suggests that bacterioplankton metabolism of phytoplankton-derived substrates are relatively more important than riverine detritus. A severe drought during 2000 resulted in record low river flow, and may have reduced role of allochthonous carbon delivery to Pensacola Bay.
Record Details:Record Type: DOCUMENT (PRESENTATION/ABSTRACT)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL HEALTH AND ENVIRONMENTAL EFFECTS RESEARCH LAB
GULF ECOLOGY DIVISION
COASTAL ECOLOGY BRANCH