Assessment of viability in the bacterial standing stock of the Antarctic Sea from the Indian side

Abstract

During the austral summer, the bacterial population along the cruise track extending from 70 degrees S and 18 degrees E to 30 degrees S and 35 degrees E are examined. During the cruise, three distinct fractions of the bacterioplankton viz. total count, total direct viable and retrievable counts were simultaneously enumerated in these waters. In the stations south of the convergent region designated as section 1 the population ranged within 10 sup(8-9) L sup(-1) whereas in the north of the region designated as section 2 they were one order higher and ranged from 10 sup(9-10) L sup(-1). The percentage of viability in the region was high corresponding to the generally high chlorophyll and primary productivity encountered in the eastern Agulhas bank. The study substantiates the hypothesis that in the Antarctic, not only the bacterial standing stock but also the active population of bacterioplankton (ca. 50%) are almost equal in abundance to those in the other oceanic or coastal regions. The viable fraction forms a hitherto unreported significant component of these waters