Microbial Ecology Biological Sciences

The Microbial Ecology lab is a research unit of the Department of Biological Sciences, Virginia Institute of Marine Science, Gloucester Point, Virginia and the School of Marine Science of The College of William & Mary.

Bacterioplankton are the smallest and most numerous autonomous organisms on the planet. Most cells are less than 0.5 microns in diameter, contain just a few femtograms (=10^-15 grams) of carbon and have rather small genomes. Yet they are numerous, reaching densities of over 1 million cells per ml in the coastal and open sea, and even higher levels in estuaries. Bacterioplankton are the most widely distributed organisms on earth, flourishing near geothermal vents in the deep sea, in polar sea ice, and all areas in between these extremes. In many areas, bacterial biomass approaches or exceeds that of phytoplankton and zooplankton: they are an important component of marine foodwebs, and important agents of nutrient cycling and geochemical reactions.

Our group studies the population dynamics and biogeochemical roles of bacterioplankton throughout the marine realm, from rivers and upland streams feeding Chesapeake Bay and the Bay itself, to the coastal oceans the open sea and the marginal ice zones on Antarctica. We measure bacterial biomass using video image analysis, and estimate bacterial productivity with a variety of approaches, including radioisotopic tracers of DNA or protein synthesis and cell division. Some of our past and current work is described in the references and websites given below. For more information, please see:

Ducklow, H. W. and F.-K. Shiah, 1993. Estuarine Bacterial Production. Chapter 11, pp. 261-284 In: T. Ford, Ed., "Aquatic Microbiology: An ecological approach," London: Blackwell. 518 p.

Ducklow, H. W., and C. A. Carlson. 1992. Oceanic bacterial productivity. Advances in Microbial Ecology, 12:113-181. New York: Plenum.