BACTERIOPLANKTON OF THE SURFACE-WATER LAYER IN THE CENTRAL ARCTIC REGION IN SPRING

The uppermost seawater layer (0 - 1 m) at 13 stations in the Central A rctic Region north-northwest of Komsomolets Island (the Novaya Zemlya Archipelago) was researched with respect to (i) the spatial distributi on and number of microbes in total and of the representatives of their groups, as well as of phytoplankton cells; (ii) the hydrocarbon conte nt of water samples. Binary correlations (r = 0.94 - 0.99; alpha = 0.0 01) among the cell numbers of bacteria of all groups capable of growin g on solid medium were revealed. Among these groups, eutrophic bacteri a dominated, their cell numbers varying from under 40 to 2140 CFU/I. O ligotrophic bacteria showed a population density from less than 20 to 1190 CFU/I, and hydrocarbon-oxidizing and hydrocarbon-tolerant bacteri a, from less than 10 to 830 CFU/I. The bacteria of these groups accoun ted for 0.0001 to 0.01% of the total number of microorganisms, which r anged from 1.90 x 10(7) to 1.10 x 10(8) cells/l at different stations. The number of phytoplankton cells in water samples varied from solita ry cells in April to 1.07 x 10(5) cells/I at the end of May. The hydro carbon content in water samples varied from 0 (at one station) to 70 m u g/l.