ZOOPLANKTON ECOLOGY IN THE MANDOVI-ZUARI ESTUARINE SYSTEM OF GOA, WEST-COAST OF INDIA

Seasonal variability in the physico-chemical features, zooplankton sta nding stock (biomass) and faunal composition in the Mandovi-Zuari estu arine system of Goa during January to December 1990 were studied. Hydr obiological characteristics were influenced by the southwest monsoon. Salinity fluctuations were drastic (0.1 to 36.6 x 10(-3)). This appear ed to cause variations in plankton production and heterogeneity of var ious taxa. Zooplankton biomass and total numerical counts varied signi ficantly between seasons and estuaries. Highest biomass values (1.9 ml /m(3)) were recorded in the Zuari estuary but the maximum counts (2570 0/m(3)) were obtained in the Mandovi estuary. Crustaceans particularly copepods predominated (54.9 to 70.6%). Invertebrate larvae, luciferid shrimps, cladocerans and chaetognaths were the other common zooplankt on groups. Diustribution and abundance of majority of constituent grou ps and species were influenced by various hydrographical characteristi cs of the environment.