Effect of Water Quality on Zooplankton in Mangrove Areas of Munroe Island, Kerala

The present study was directed to evaluate the influence of water quality variables on selected zooplankton groups in the Munroe Island. Ten sampling stations were selected and zooplankton samples were collected with WP net (200 μm). Fourteen water quality parameters were considered for the analysis to recognize their influences on zooplankton community. The pH ranged from 6.90 to 7.53.The level of solids, conductivity, salinity, total alkalinity and total hardness was high in Pattamthuruthu when compared to other stations. Palliyanthuruthu registered a minimum DO. The BOD and COD varied from 0.17 to 0.876, 9 to 19 respectively. The Pezhumthuruthu shows maximum abundance of zooplankton (72745No/m³) and minimum at Kidapram I (8002No/m³). Among the zooplankton communities, copepoda showed maximum abundance (32740No/m³) and chaetognatha minimum (3No/m³).The water quality variables such as totalhardness, total alkalinity, salinity, temperature, electrical conductivity and total dissolved solids tend to increase towards the sampling stations adjacent to the Ashtamudi estuary. The variation in zooplankton abundance and hydrological features clearly corroborate the influence of Ashtamudi estuary and similarly the influence of Kallada River on Villimangalam, Kidapram II and Kidapram I was also reflected during the study period. The zooplankton abundance in Munroe Island was significantly influenced by the variations in water quality due to various natural as well as anthropogenic stresses.