Occurrence of diatom blooms in Bahuda estuary, east coast of India

Abstract

99-101Blooms of Asterionella glacialis, Thallassiothrix fraunfeldii, Coscinodiscus centralis and C. excentricus were encountered successively in May 1991, September 1991 and June 1992. Cell counts of these bloom forming species accounted for about 80, 93 and 46% of total phytoplankton density of 2.67 x 10(6), 2.16 x 10(6) and 3.69 x 10(5) cells.l(-1) respectively. Thallasiothrix bloom occurred under low salinity (13.9 +/- 2.7 x 10(-3)), while the other species bloomed under typical marine conditions (< 30 x 10(-3)). A record fair of NO3--N was observed during Asterionella glacialis bloom