Community structure of meiobenthos from a tropical estuary

Abstract

Meiofaunal samples were collected from 3 stations, located in the salinity gradient of Zuari Estuary of Goa. Spatially the abundance of meiofauna decreased from lower to upper reaches and followed the trend of salinity distribution in the estuary. The population density showed clear seasonal abundance, the maximum being in premonsoon and the minimum in southwest monsoon season. The fauna showed remarkable recovery after monsoon, due to their resilient nature. Free living nematodes were most dominant, contributing over 50% of the total meiofauna in terms of number and biomass. They were followed by benthic copepods and ostracods/turbellarians in the order of abundance. Vertically, over 60% of the fauna occurred within the top 2 cm of the sediment and the faunal density reduced significantly in the deeper layer. Salinity and availability of food influenced the fauna horizontally while chlorophyll a and interstitidal water were important in determining the vertical distribution.