PRELIMINARY OBSERVATIONS ON THE HYDROGRAPHY AND INSHORE PLANKTON IN THE BAY OF BENGAL OFF VISAKHAPATNAM COAST

Abstract

PLANKTON investigation in Indian waters is in its infancy and most of the
observations so far made are confined to a narrow coastal belt of water not
exceeding two to five miles width, the samples being collected by towing
a net from country crafts like the catamaran. Sewell (1913) gave the earliest
account of the plankton from the south-east zone of the Bay of Bengal, based
on a large number of samples collected from R.I.M.S.S. " INVESTIGATOR "
during the survey season 1910-12. He found that while in the northerly
region of the zone under survey the plankton exhibited a regular banded
arrangement, there was uniform distribution of the plankton in the southerly
region. Other studies have so far been largely confined to the inshore
waters. Menon (1931), Aiyar et al. (1936), and Rama Murthy (1953)
studied the qualitative and quantitative aspects of the plankton off the coast
of Madras City. Chacko (1950), Prasad et ah (1952) and Prasad (1954)
have made preliminary investigations on the seasonal variations and distribution
of the plankton in the Gulf of Mannar. Ganapati and Murthy (1953)
made a preliminary survey of the quantitative variations of the phytoplankton
at various depths and distances in the neritic waters off Visakhapatnam.
In addition to these general investigations accounts of special groups of
planktonic organisms from the Bay of Bengal are also available.