ZOOPLANKTON PRODUCTION, COMPOSITION AND DIVERSITY IN THE COASTAL WATERS OF GOA

Spatial and temporal variability in zooplankton production, compositio n and diversity iri the coastal waters of Goa were studied. Zooplankto n production was bimodal with primary peak during September-October an d secondary peak during March-April. Secondary production computed fro m the zooplankton biomass values fluctuated between 24.7 and 87.2 mgC. m(-2).d(-1). Herbivores dominated the zooplankton community and copepo ds were most abundant. Cladocerans, pteropods and decapod larvae, serg estids, siphonophores, chaetognaths and fish eggs were the other commo n taxa. Zooplankton population was never dominated by a single group. Swarms of copepods (Temora turbinata), cladocerans (Evadne tergestina) , and pteropods (Creseis acicula) occurred in the nutrient enriched en vironment during early postmonsoon months (October-November). Swarming of these zooplanktonic forms resulted in high biomass but low diversi ty community. Faunal and species diversity were enhanced with increase of carnivores in the ecosystem. An inverse relationship between zoopl ankton biomass and species diversity was the general trend. A total of 58 species of pelagic copepods belonging to calanoids(42), cyclopoids (12) and harpacticoids(4) were identified. Their occurrence and abunda nce were influenced by seasons, depth of sampling station and prevaili ng hydrographic conditions. Niche partioning among congeners was evide nt.