Status of Commercially Exploited Demersal Fishery Resources of India

Demersal fishes can be divided into two main types: strictly benthic fish which can rest on the sea floor, and benthopelagic fish which can float in the water column just above the sea floor. Benthic fish, which are rest on the sea floor, sometimes called groundfish. World catches of demersal species increased rapidly during the first three-quarters of the 20th century. Demersal finfishes are one of the major components in the marine fish landings along the Indian coast. The demersal fisheries in India have exploited many major fish groups of different biological characteristics occupying a variety of ecological niche. The major gear which exploit the demersal finfish resources in India are bottom trawlnets. Large species are mainly caught by bottom set gillnets. Some demersal finfishes are taken as a by-catch in Indian trawl fisheries. Demersal fish though generally occupy the seafloor; feeding on the benthic organisms and detritus, perform vertical and horizontal migration in search of their feeding and breeding grounds. Hence, the day and night catches in bottom trawl show differences, eg. catfish, rays, eels etc. In the inshore fishing activities below 50 m depth, occurrence of pelagics in bottom trawl and catfish, perches and penaeid prawns in pelagic net is common. Trawl catch consists of 76% demersal (finfish 38% and inveretebares-38%) remaining pelagic or column water fishes.