Article

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

Marine Biological Laboratory Ecosystems Center 02543 Woods Hole MA USA
Microbial Ecology (Impact Factor: 3.12). 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.

1 Follower
 · 
96 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The growth characteristics of small (0.2-1.0μm) and large (1.0-3.0 (μm) free-living and attached bacteria were studied in Lake Constance by comparing the spatial and seasonal dynamics of their biomass turnover time (ratio of biomass/production). The biomass of small free-living bacteria usually turned over significantly faster than that of large free-living bacteria throughout the water column. The turnover of attached bacterial biomass was characterized by large fluctuations. Occasionally, in aphotic water layers, it was as long as that of large free-living bacteria, but when large amounts of decaying organic particles were present, it was shorter than that of small free-living cells. Biomass turnover times of free-living bacteria were in the same range as their generation times, which were estimated from the increase in bacterial abundance in 3μm prefiltered samples. The biomass turnover time of actively metabolizing bacteria was comparable to the generation time of actively metabolizing cells. These results indicate that the biomass turnover time is a useful indicator of the growth of different bacterial fractions, as it reflects their different amounts of participation in microbial processes of aquatic ecosystems.
    Microbial Ecology 03/1988; 15(2):151-63. DOI:10.1007/BF02011709 · 3.12 Impact Factor
  • Journal of Plankton Research 05/1987; 9(3):535-552. DOI:10.1093/plankt/9.3.535 · 2.26 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Bacterial community dynamics were investigated over seasonal and basin scales within the York River estuary, Virginia. Variables describing bacterioplankton dynamics were measured at 6 stations spanning the entire salinity gradient (0 to ca. 20 psu over 60 km). Samples were collected monthly from June 1996 through May 1997 and every other month from June 1997 through May 1998. Bacterial abundance and production were high throughout the estuary. Bacterial abundance ranged from 4.4 x 10(8) to 1.3 x 10(10) cells l(-1). Incorporation of (3)H-thymidine ranged from 10 to 863 pmol(-1) h(-1) while (3)H-leucine incorporation rates ranged from 25 to 1963 pmol l(-1) h(-1). A strong relationship between bacterial properties and temperature was found with clear seasonal trends. On a basin scale, bacterial properties were strongly related to changes in salinity, suggesting that freshwater inputs and estuarine circulation controlled the distribution of bacterial abundance and activity in the river. Although there was a great deal of variability from month to month, 2 opposing trends were consistently found: bacterial abundance increased from freshwater to the mouth of the river, while incorporation rates decreased from freshwater to the mouth. These patterns imply a strong landward gradient in specific growth rates, and thus a close match between production and removal near the freshwater endmember and throughout the estuary.
    Aquatic Microbial Ecology 01/2003; 30(2):135-148. DOI:10.3354/ame030135 · 1.90 Impact Factor

Full-text (2 Sources)

Download
10 Downloads
Available from
Aug 12, 2014