Impact of Trawling in Indian Waters - A Review

Trawling which is the highest contributor to the marine fishery in India has undergone sea change as a fishing technique and fishing pattern. During recent years, the reduction of catch per unit effort from existing fishing grounds led to various modifications in trawl net design and trawling operations, which has resulted in increase in fish production. Impacts of trawling in Indian waters have been monitored by various agencies during last 25 years. Although there are a good number of articles in peer reviewed journals, a huge quantity of useful information still lies in the form of reports and grey literature which is not easily available to the researchers. This paper attempts to compile information available from various research papers, reports and presentations in seminars and symposia, to serve as an updated guide for trawl impact studies. The information are categorized as (i) impact on the ecosystem, (ii) impact on fishery and (iii) impact on biodiversity. The paper also analysis recent trends in trawling like pelagic and high speed trawling in Indian waters, taking up an example from the trawl fishing off Karnataka, south west coast of India. It was seen that after the introduction of high speed pelagic trawling, some of the areas which were unsuitable for trawling, have also been brought under exploitation. The utility of log book data in resource conservation studies and the need for incorporating spatial studies in trawling impact assessment in the context of ecosystem stability and fishery sustainability are also discussed