Short-term variations of bacterioplankton in Antarctic zone: Terre Adelie area.

Previous studies on Antarctic seawater have demonstrated the presence of significant numbers of bacteria, but their in situ activity has not been demonstrated. In order to demonstrate this hypothetical activity, a scheduled survey was conducted from January to February 1986 in a coastal area of Adelie Land. Seawater samples were collected in a selected station every day or every hour during a 17 hour period. Bacterial communities in each sample were studied by measuring direct and viable counts, frequency of dividing cells estimation, taxonomic analysis, and heterotrophic potential. Complementary studies used batch cultures with artificial nutrient supplements. The results clearly suggest a strong potential activity of the natural Antarctic bacterial microflora.