Study finds disturbing evidence of marine plastic pollution off Kerala coast

EU-funded project in University of Kerala to document underwater diversity finds plastic bottles, bags, fishing nets, and fragments of single-use plastics beyond 40-metre depth off Kerala coast

Researchers have found unsettling evidence of plastic dumps in the ocean beyond 40-metre depth off the Kerala coast that are posing a grave threat to marine life forms.

An expedition to document underwater biodiversity led by the European Union-supported Project Ecomarine in the Department of Aquatic Biology and Fisheries, University of Kerala, found reefs beyond 40 metres depth dumped with plastics. Underwater sites were littered with plastic bottles, bags, fishing nets, and fragments of single-use plastics, according to the findings published on Wednesday.

Peril of ‘ghost nets’

The documentation revealed the direct impact of plastic pollution on marine species, the researchers said. Marine creatures were seen struggling to free themselves from discarded fishing nets, while others were found ingesting plastic fragments, mistaking them for food. Plastic fishing nets, possibly discarded by fishers, were found on several deepwater reefs. These ‘ghost nets’ pose a grave problem as they trap creatures, and remain a permanent threat to underwater life.

The diving team included Umeed Mistry of Earth CoLab, Bengaluru and noted underwater photographer and filmmaker Jonah Skoles, Eternal Divers, Puducherry.

Role of rivers, sewers

The findings highlight the deadly consequences of plastic pollution on marine biodiversity, calling for increased efforts in waste management, recycling and the adoption of sustainable practices, A. Biju Kumar, Professor and Head, Department of Aquatic Biology, said. They also call for serious thought on upstream management of plastics, as rivers and sewers drain plastic waste into the ocean on a daily basis, according to him.

‘’Underwater rocky reefs have a wealth of Gorgonians (sea pens, sea fans) and solitary corals. These areas at a depth of 50 metres may be called ‘animal forests’ as the biodiversity is so rich, including the rare soft corals, solitary hard corals, sponges, worms, molluscs, bryozoans and ascidians. In this environment, huge schools of fish are also present,’‘ he said.

A wake-up call

While plastic dumps have been reported in shallow waters, this is the first instance of a study being conducted on rocky reefs beyond 40 metres off the Kerala coast. ‘‘The discovery of additional plastic dumps in the ocean off Kerala is a distressing wake-up call. It is crucial that we take immediate action to reduce plastic consumption, promote responsible waste management, and develop sustainable alternatives to plastic. Our marine ecosystems and the livelihoods of coastal communities depend on it,’‘ says Biju Kumar.

The study is in its first phase, and ongoing investigations are expected to unravel the richness of biodiversity as well as threats to the system.

The Project Ecomarine apart, the University of Kerala, in its Budget speech for 2022, had announced a project for the digital documentation of biological and archaeological heritage in the coastal seas of Kerala.