KOCHI: From the riff-raff floating on contaminated waters to microplastics in the guts of fishes, the menace of marine debris is widespread and has now started impacting the livelihood of coastal communities.
“It was never acknowledged as a problem earlier but for the last couple of years, we have been getting serious complaints from fisherfolk who say that their catches have more plastic waste than fishes. We are getting reports and evidence of microplastics found in the guts of fishes,” said V Kripa, head, fisheries environment management division, Central marine fisheries research institute (CMFRI).
Stakeholder meetings have seen fishermen complaining of various plastic objects that get caught in their stake nets. “Since we are in a tropical zone, our waters are turbid and carry lot of mud in the flow. When a plastic kit is dumped into the water, mud settles in along with everything else that’s there in the waters. This makes it heavy and it sinks to the sea-bed. These objects get entangled in the stake nets. When they pull, it has lot of weight and this leads to damage of the nets also,” she said.
The debris include nylon ropes, parts of fishing nets, plastic covers, carry bags, PET bottles, containers of milk, creams, oil, ointments, synthetic slippers, glass bottles, electric bulbs, CFL bulbs and e-waste like TV/computer hardware, mobile phone handsets or parts, chargers, battery operated toys and Styrofoam.
Yet another problem is ghost nets – fishing gear and nets that have been abandoned or lost due to damage or accidents. Often dolphins, turtles, crabs and other organisms that reside in the bottom of the sea get caught in the ghost nets which gets entangled in nets of trawlers.
“We need to work out longterm solutions for the fishermen who are directly affected by ghost nets. It is important to address the removal of ghost gear with the participation of fishing communities. In case of gill nets, there are higher chances of it being lost, so we need to look at modifying of fishing vessels so that there is not much loss of gear,” said Ajay Venkataraman, marine programme officer, World Wildlife Fund, Delhi.
Almost 90% of the waste found in oceans are plastics. “In addition to plastic waste, hazardous electronic waste is also contributing to the destruction of marine ecosystem,” said N G K Pillai, former director, CMFRI.
Role played by microplastics, pieces of plastic debris less than five millimetres, in transferring persistent organic pollutants to the food web has opened a new dimension to marine pollution. “As plastic gets smaller and smaller, they release chemicals. One of those chemicals has been identified as Bisphenol A which can interfere with reproductive systems of marine fauna. Micro and macro plastics have been observed at all trophic levels starting from sardines to tunas and sea birds,” Kripa said.
The quantity of debris flowing into the coastal ecosystem was found to be considerably higher during the full moon and new moon period coinciding with the spring tides, she added.