Derelict fishing gear abundance, its causes and debris management practices – Insights from the fishing sector of Kerala, India

Abstract

Commercial fishing activities are far from free of environmental consequences and can be a major source of marine plastic pollution. Information on the types and fishery-specific causes of derelict fishing gear (DFG) as well as fishers' behaviour contributing to marine debris is lacking from several fishing-intense regions of the world. The present study investigated the contribution of commercial fishing activities to marine plastic debris in the coastal Indian state of Kerala, using data from a survey of 390 fishers operating trawl, seine, gillnet and trammel net gear types as well as a litter assessment on 25 beaches. The findings suggested that the mismanagement of plastic wastes onboard fishing vessels and the loss/discard of fishing gear are the major causes of DFG in the region. The disposal practice of damaged fishing gear, galley waste and debris caught during fishing activities differed among different fishing gear users. Discarding damaged nets on beaches was a common practice among non-motorized gillnet users. Trawl and ring seine fishers threw debris caught during fishing back into the sea, whereas shore seine and mini trawl fishers disposed of it on the shore. Lack of waste collection facilities was the main reason (93 % of respondents) for improper disposal of damaged fishing gear and other plastic litter. DFG was the largest single-category litter (53.4 %) in terms of weight along the beaches of Kerala. Ropes (including rope cut-offs), gillnets/gillnet pieces and trawl pieces formed the major share of DFG. The abundance of DFG on the beaches had a positive correlation with the number of fishing vessels operated from there. The high share of DFG along the Kerala coast highlights the need to prioritize the fishing sector in management efforts to reduce marine litter. Given the anticipated rapid growth in global fishing activities, it is imperative to develop sector-specific plastic litter quantification and management strategies to tackle the growing problem of marine debris.