Plankton Composition and Water Quality Analysis of Batticaloa Lagoon qt Solid Waste Dumping Site, Eravur, Sri Lanka

Study was aimed to assess the composition, richness of plankton species with physico-chemical water quality parameters. Total of six sampling stations (L1-L6) were selected for this survey through a transect line along the lagoon from the land at different distance. Study was carried out for three months, fortnightly. The water quality parameters and plankton were measured by standard procedure. Total of 83 species of phytoplankton of six divisions were identified in which Bacillariophyceae is most diverse (50% composition) followed by Chlorophyceae, Charophyceae, Cyanophyceae, Euglenophyceae and Dinophyceae. Total of 26 species of zooplankton of five divisions were recorded, in which rotifers account for most diverse group (63% composition). Nitrate, phosphate and dissolved oxygen level showing variation (P < 0.05) along the sampling points. The composition and abundance of plankton species were strong positively correlated with nitrate, phosphate, turbidity and electrical conductivity; pH, dissolved oxygen, temperature and salinity were negatively correlated. The presence of bio-indicators were evident that the lagoon is subjected to pollution. The sampling point near to land (L1) resulted nutrition rich condition than the sampling points distanced from land into lagoon (L2-L6). Proper mitigation ways against pollution inputs (solid-waste dumping) were needed to ensure lagoon utilization in sustainable manner.