Chennai: A recent study conducted by Gunasekaran Kannan and his team at the Centre for Aquaculture at Sathyabama Institute of Science and Technology in Chennai sheds light on a concerning issue—marine organisms piggybacking on plastic, rubber, glass, foam sponge, metal, and wood debris to reach the shores of southeastern India. The study, published in the Marine Pollution Bulletin in September 2023, identified 17 marine species attached to various debris items on the Bay of Bengal coast, ranging from Puducherry to Parangipettai in Tamil Nadu.
Among the discovered species is the invasive tropical American brackish water mussel, Mytella strigata, known to impact fishing in Kerala backwaters. The study raises dual concerns about marine pollution and invasive species, emphasizing the potential risks to local biodiversity.
The research focuses on the lesser-studied aspect of marine litter as a carrier for species dispersal in India, one of the world’s largest producers and consumers of plastics. The study highlights the variety of items serving as carriers for marine organisms, including plastic fragments, bottle caps, lids, bottles, jars, and food containers.
Kannan, recalling his fieldwork experiences on the beaches of Puducherry and Parangipettai, noted the attachment of barnacles and algae to diverse items such as water bottles, ropes, nets, bags, and clothes. The study gathered samples from eight sites, including urban and small fishing villages, revealing the prevalence of marine litter and its potential impact on biodiversity.
The organisms identified in the study belong to seven major categories, including arthropods, moss animals, annelids, cnidarians, chlorophyta, and foraminiferans. Approximately 400 non-native species of mussels, barnacles, sponges, sea squirts, and bristle worms globally raft on marine litter, posing a threat to local organisms.
The study underscores the annual influx of 4.8-12.7 million tonnes of marine litter into global marine habitats and its long-distance travel. Marine litter not only endangers marine megafauna through ingestion and entanglement but also serves as a vector for the introduction of invasive species.
The invasive American mussel, Mytella strigata, was found abundantly on various debris items, raising concerns about its potential spread through marine litter. The study emphasizes the need for heightened awareness, detailed studies, and conservation measures to address the dual challenges of marine pollution and invasive species.
As coastal villages in south India express concerns about changing marine species and potential irreversible ecosystem damage, scientists advocate for effective strategies to control marine plastic pollution in pristine waters and clean beaches, such as the Nicobar archipelago.
