An impact of tropical cyclone on meiobenthic fauna of Chennai coast, Tamil Nadu, India: A case study of cyclone Mandous

The meiofaunal diversity is used as an indicator to assess the complex and diverse impacts on the coastal environment during the natural calamities. The present study evaluates the effects of Mandous cyclone on ecologically two different stations, Pattinampakkam beach and Adyar estuary, which are located on Chennai coast, Tamil Nadu, India. The impact of the Mandous cyclone on physico-chemical parameters and meiobenthic faunal composition was investigated during, prior to, and after the cyclone. Thirty-nine species of meiofauna belonging to 15 taxa were recorded in both the stations. Nematoda, Oligochaeta and Harpacticoida taxa occurred with higher diversity and abundance than other meiofaunal taxa. Among these taxa, Polygastrophora sp. of Nematoda, Grania pusilla of Oligochaeta, and Arenosetella indica of Harpacticoida were the predominant species recorded during the study period. There was a prominent decline in the population density of meiofauna due to the Mandous cyclone, and thereafter, it took three weeks for recolonization and restoration to normalcy. Statistically, significant impact of the Mandous cyclone on the diversity, density, and evenness of the meiofaunal community with abiotic factors were observed through the Ecological indices and Canonical Correspondence Analysis. The Mandous cyclone assessment with special emphasis on meiofaunal communities allowed to fill the gap with knowledge regarding the diversity, abundance, composition, and distribution of meiofauna between pre- and post-Mandous cyclone, which helped in understanding the physico-chemical changes and response of meiofauna in a sandy beach and estuary.