Sustainable Ocean Resources Network

Abstract

The present study carried out in order to understand the composition of zooplankton and their potentiality as bio indicators in Sri Lankan coastal waters. The study was carried out during the day time in a six months period in 2012. Samples were collected at major ports, fishery harbours and certain important native coastal habitats of Galle, Hambanthota and Trincomalee. A total of 79 zooplankton varieties representing nin major phyla; Protozoa, Cnidaria, Rotifera, Mollusca, Annelida, Arthropoda, Echinodermata, Chaetognatha and Chordata, were identified in the study. Of these, majority of them are Copepods belonging to four major orders; Calanoida, Cyclopoida, Poecilostomatoida and Harpacticoida and they represented more than 50% of the total species identified. The presence of small sized Poecilostomatoids in higher densities and the presence of large sized Calanoids and Harpactioids in low numbers may indicate the prey-predator relationship among these orders. Zooplankton diversity indices in all the studied locations were below 3.00. In majority of habitats higher BOD values were reported, few habitats were moderately or highly polluted. Further, presence of few number of Calanoid species with minimum of their densities can be considered as an indicator of water pollution.