Institute says plastic pellets could have been dropped accidentally during transportation; rules out possibility of terrestrial discharge of plastic through rivers
PANJIM: Goa’s coast is now facing a bigger threat and marine organisms are at risk as large quantities of plastic debris wash ashore during the southwest monsoon period. The plastic dropped accidentally from vessels during transportation by ship, is posing a big challenge to the coastal environment.
A study by National Institute of Oceanography (NIO) scientists along six beaches of Goa concluded that plastic debris moved in during the monsoon season from the ocean and may lead to a major threat to marine organisms. It has ruled out the possibility of terrestrial discharge of plastic through the rivers of Goa into the Arabian Sea.
The study called ‘Characteristics, seasonal distribution and surface degradation features of microplastic pellets along the Goa coast’ was conducted by group of NIO scientists including S Veerasingam, Mahua Saha, V Suneel, P Vethamony, Andrea Carmelita Rodrigues, Sourav Bhattacharyya and B G Naik.
Microplastic pellets (MPPs) are ubiquitous contaminants, recognised as a serious threat to the biotain coastal, estuarine and marine environment. The distribution, abundance, weathering and chemical characteristics of MPPs on Goa’s beaches, and their transport to the coast during the southwest (SW) monsoon has been studied.
MPPs were collected from six beaches along the Goa coast during the northeast (January 2015) and southwest (June 2015) monsoon seasons. The beaches include Keri, Vagator and Calangute in North Goa and Colva, Mobor and Galgibag in South Goa. Around 100 MPPs were collected from the high tide line of the sandy surface of each beach.
“A total number of 3000 MPPs were collected from six beaches along the Goa coast during January-June 2015. Overall, the occurrence of total MPPs on beaches along the Goa coast was found to be higher in June (1655 pellets) than January (1345 pellets). Significant variations were observed in abundance of MPPs on beches during that period,” the study reveals.
“The strong ocean currents during SW monsoon could be playing a major role in pushing the micro plastic residue floating on the sea due to accidental spillage from ships during its transportation onto Goa beaches,” the study explains.
The study claims that though it observed many secondary microplastics (plastic films, fibres and fragments), could not find any MPPs in estuarine waters. As there are no MPP manufacturing industries in Goa or nearby coastal regions, the distribution of MPPs along the Goa coast is likely to be marine based sources (unintentional spillage in international and national shipping routes and/or neighbouring countries) than land based sources. “Therefore, ruled out the possibilities of terrestrial discharges of MPPs through the rivers of Goa into the Arabian Sea,” NIO said.