Impact of tropical cyclone Ockhi on the marine fishery resource assemblages along the Kerala and Tamil Nadu coast, India

Abstract

Extreme weather events such as tropical cyclones strongly influence marine fishery landings along the Indian coast. This paper assessed tropical cyclone Ockhi's impacts on the marine fishery resource assemblages along the Kerala and Tamil Nadu coasts. Apart from this, variation in environmental variables during the cyclone and their association with fishery was evaluated. The catch composition before, during, and after the Ockhi was determined using the SIMPER (Similarity Percentages) analysis. The species dissimilarity was high during and after the cyclone compared to the pre-cyclone data. The main environmental variations noticed during Ockhi were the decline in sea surface temperature, a hike in chlorophyll, salinity, and upwelling. Moreover, current speed and direction variations were observed during the cyclone month, and it might have badly affected fish recruitment. The study revealed the exponential changes in fish abundance during the cyclone and showed a sign of recovery in the post-cyclone period. This indicates that ecosystem changes due to such extreme events are not long-lasting, and the beneficial ecological changes in the habitats were helpful for the higher fish landings in the post-cyclone period.