Fishing areas off Mumbai have highest plastic waste concentration
The United Nations Environment Programme (UNEP) estimates that the highest concentration of midsea plastic has been recorded in the North Pacific Gyre, located at the north Pacific Ocean at 18kg/sq km.Updated: Dec 28, 2018 08:28 IST
Fishing areas off the coast of Mumbai have the highest concentration of plastic waste in the country, according to a study by the Central Marine Fisheries Research Institute (CMFRI).
The study, which covered five major fishing grounds along the country’s coast, found that sites off Mumbai had 131.85 kg of plastic per square kilometre, followed by Tuticorin at 93.34 kg/sq km, Ratnagiri at 73.16 kg/sq km, Visakhapatnam at 4.95 kg/sq km, and Kochi with 1.55 kg plastic per sq km.
The United Nations Environment Programme (UNEP) estimates that the highest concentration of midsea plastic has been recorded in the North Pacific Gyre, located at the north Pacific Ocean at 18kg/sq km. Data released by the United Kingdom government from 2017 showed an average of 358 litter items per square kilometre of seabed and fishing areas, which included 78% plastic and micro plastic.
The findings were derived through an internationally accepted methodology called swept area method, which was also used to calculate density of marine organisms.
The researchers visited fishing landing sites between Janaury and December (except during the monsoon) and studied fish samples, plastic debris and fishing nets to estimate concentration of plastic waste.
Plastic waste is getting into the sea at an alarming rate, said KV Akhilesh, scientist from CMFRI Mumbai. “Earlier, we used to see organisms trapped or entangled in plastic debris, now we can see plastic in their stomach content, which means plastic is abundantly available and increasing along coastal waters,” he said. “Even during our deep surveys, plastic debris was collected more than 1000m deep from Arabian Sea.”
CMFRI conducted experiments at 20 -30 metres depths and found four fish species and two shark species with plastic in their stomach. Plastic was found in the stomach of a dolphin from the waters off Gujarat and a plastic spoon in a whale shark’s stomach. Species found along the Mumbai coast such as tuna, mahi mahi, threadfins (rawas), croaker (dhoma), and two shark species, spadenose and hammerhead, had plastic in their stomach.
While there has been no conclusive study on the harmful effect on human health due to consumption of fish with plastic in their bodies, experts said these were initial warning signs. “Mostly, the stomach of fish is removed before consumption but the rate at which plastic is increasing, it will not take much time for micro plastic and plastic microbeads to spread to other parts of these fish. Remedial measures need to be initiated immediately, especially along the Mumbai coast,” said Dr Baban Ingole, head of marine biology department, National Institute of Oceanography.
Akhilesh said untreated municipal sewage is taking plastic waste into the sea. “By placing nets, plastic that is arriving through drainage or creeks need be sieved out. More awareness programmes in coastal areas need to be conducted along with action on ground for proper disposal of plastic,” he said.
“While the plastic ban has considerably reduced total quantum of plastic generation, hundreds of tonnes is already at sea. Efforts have to be focused towards reducing that.”
“Single use plastics are reaching oceans — like plastic bottles, pouches of snacks, milk covers, etc. Proper collection mechanisms are absent in many areas of city, so people deliberately throw the waste in public spaces, including beaches,” said E Vivekanandan, former principal scientist and current national consultant at CMFRI.
A study released in February by CMFRI of 254 beaches across 11 states and Union Territories, which share India’s 7,516km coastline, found that beaches in Goa had the highest quantity of plastic debris in India with every metre of beach sand having an average 25.47g of plastic.
After Goa, 33 beaches in Karnataka were found contaminated with plastic with a concentration of 21.91g/m2, followed by 12 beaches in Gujarat at an average 12.62g/m2. The quantum of litter on Karnataka’s beaches was 178.44 g/m2 and 90.56g/m2 in Gujarat.
Andaman and Nicobar Islands and Lakshadweep followed with 8.97 g/m2 and 4.37 g/m2, and the lowest average quantity of plastic litter was identified at Odisha at 0.08g/m2.
First Published: Dec 28, 2018 08:28 IST