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Distribution and activity of bacteria in the headwaters of the Rhode River Estuary, Maryland, USA

Biology Department Whitman College 99362 Walla Walla WA USA; Marine Biological Laboratory Ecosystems Center 02543 Woods Hole MA USA
Microbial Ecology (Impact Factor: 3.28). 08/1984; 10(3):243-255. DOI: 10.1007/BF02010938

ABSTRACT A transect along the axis of the headwaters of a tidal estuary was sampled for microbial, nutrient, and physical parameters. Chlorophylla averaged 42g 1–1 and phytoplankton comprised an estimated 80% of the total microbial biomass as determined by adenosine triphosphate (ATP). Bacterial concentrations ranged from 0.3–53.9106 cells ml–1 and comprised about 4% of the total living microbial biomass. Bacterial production, determined by3H-methyl-thymidine incorporation was about 0.05–2.09 109 cells 1–1 h–1, with specific growth rates of 0.26–1.69 d–1. Most bacterial production was retained on 0.2m pore size filters, but passed through 1.0m filters. Significant positive correlations were found between all biomass measures and most nutrient measures with the exception of dissolved inorganic nitrogen nutrients where correlations were negative. Seasonal variability was evident in all parameters and variability among the stations was evident in most. The results suggest that bacterial production requires a significant carbon input, likely derived from autotrophic production, and that microbial trophic interactions are important.

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