Estimation of the plankton population, diversity and correlation analysis with sustainable fishery of the Ashtamudi estuary and Thekkumbhagam creek, Kerala India

Abstract

The Thekkumbhagam creek of Ashtamudi estuary is having a high potential for fishery development and as per the available records no scientific study on availability of the commercial fauna pertaining to the Thekkumbhagam creek alone has been conducted so far. The present study deals with the evaluation of the impact of eco-touristic activities on the availability of commercial fauna of the creek. For adequate information the study focuses on the four selected stations of Thekkumbhagam creek namely Pallikodi (station 1), Kaadanmoola (station 2), Munambathukadavu (station 3), Sankaravilasam kadavu (station 4). Around 51 species of fishes, 7species of shrimps, 2 species of crabs, 5 species of bivalves and a single species of oyster were encountered from the selected four stations. In station 1, the Shannon Diversity index and species richness of fishes and shrimps were comparatively higher than other stations. In station 2, the evenness index was greater than that of station1. Station 3, diversity indices and species richness were much lesser than that of station 1 and station 2 but greater than station4.Study point out that many species in the study area are being threatened by various human activities. Correlation analysis between phytoplankton and diversity indices revealed that a significant positive relationship existed between species richness and diatoms in all stations except station 4. A significant positive correlation between rotifer and dominance index was noted. From the present study it is concluded that the best approach to the conservation of this species is to disseminate conservation information, education and practices to fisherman and stake  holders  about  the  danger  of  extinction  of  species.  It is important to adopt measures for the rehabilitation of fishery stocks that shows symptoms of depletion.