Marine plastic litter in certain trawl grounds along the peninsular coasts of India

Abstract

Non-biodegradable marine debris such as derelict fishing gears and their parts, polythene covers, carry bags, synthetic packaging materials etc., cause serious damages to the benthic ecosystem including the marine biota. We report here the monthly variation in the marine plastic litter (MPL) and its relative percentage to the quantity of fish caught from the trawling grounds off Cochin, Ratnagiri, Mumbai and Veraval along the west coast as well as Visakhapatnam from the east coast of India. The mean values of MPL from the fishing grounds registered the maximum of 55.2 +/- 16.52 kg/km(2) off Veraval and the minimum of 2.11 +/- 0.55 kg/km(2) off Visakhapatnam, registering a national average of 10.95 +/- 3.05 kg/km(2). The relative percentage of MPL over the fish catch remained highest (3.83%) at Veraval and lowest from Visakhapatnam (0.33%) while, the national average was 1.89 +/- 0.28. Monsoon season registered maximum MPL in the fishing grounds of all the coastal regions we studied. Depth of the trawling grounds also influenced the quantity of MPL that 20 m depth registered quantity (24.25 +/- 9.16 kg/km(2)) and the overall mean at 10 m and 40 m depth zone are significantly different from that of 20 m. The database created through this study are discussed in the light of increasing deleterious effects of plastic pollution in the active fishing areas in coastal region and the urgent need to save the sea for sustainable use of its resources.