Coastal Aquaculture and Mariculture

Unit 8- Deep sea fisheries

8.1.5. Commercial exploitation of deep sea crustaceans along the southwest Coast
Until late 1990s, it was considered that deep-sea resources could be exploited only by large trawlers. These resources were considered beyond the reach of small and medium trawlers, operating in the coastal waters. From November 1999, the fishermen of Kerala, and from 2001, the fishermen of Karnataka are engaged in deep-sea fishing by employing conventional trawlers. The major deep-sea pandalid shrimps landed at Kochi Fisheries Harbour are Heterocarpus woodmasoni, H. gibbosus, Plesionika spinipes, Aristeus alcocki, Metapenaeopsis andamanensis, Solenocera hextii and Penaeopsis. The deep-sea lobster fishery is supported by a single species, viz. Puerulus sewelli.
In the last three years, the fishermen of Tamil Nadu also have ventured into deep-sea trawling up to 400 m depth. Extreme caution should be exercised in exploiting deep-sea resources. Deep-sea shrimp fishery is characterized by the absence of juvenile populations and heavy dominance of berried, impregnated or mature females of almost all species. Compared to coastal species, the fecundity of deep-sea species is low and growth rate is slow. Because of these disadvantageous biological characteristics, most of the deep-sea resources including penaeid prawns are extremely vulnerable to fishing. Taking these biological limitations into account, it is advisable not to increase fishing pressure on these fragile stocks.