Assessing vulnerability and adopting alternative climate resilient strategies for livelihood security and sustainable management of aquatic biodiversity of Vembanad lake in India

The present study was carried out at the Thycattussery area in Vembanad lake and assessed the ichthyo-diversity, variability in climatic variables, the exploited status of predominant small-scale sector fisheries (SSFs) and impact of climatic variables upon an existing SSF. Fish, as well as clam specimens collected from the study area, were identified. Diversity indices and dominance curves helped to identify monsoon (June–September) as the diverse season in the wetland. SIMPER (similarity percentage) analysis indicated that Villorita cyprinoides (clam) was the predominant species in the wetland with a mean relative abundance of 16.1%. Canonical correspondence analysis (CCA) of variables with clam production identified calcium hardness and rainfall with axis loadings of –0.56 and 0.50 respectively as the variables predominantly contributing to clam production. Stepwise regression indicated that temperature and rainfall were the determinants of clam production. A decrease in rainfall and an increase in temperature at an annual rate of 0.02 and 0.8%, respectively, decreased the clam production by 5.37%/year in the study area. Further, the generalized linear model (GLM) indicated stagnancy in clam production until 2035 below 400,000 kg per year. The study introduced diversification of livelihood systems using clam culture in climate resilient pen structures (CRPS) as an adaptation strategy.