Over 80 per cent of current fishing activity is confined to the shallow waters near the seashores. There are several adverse impacts to overexploiting the coastal areas. The number of fish catches per trip in this zone is declining rapidly. This has, in turn, spurred fishermen to reduce the mesh size of trawl nets, thereby netting large quantities of non-targeted and unwanted fish. More importantly, marine fish output is stagnating.
On the other hand, there are also valid impediments for the common fishermen from venturing into offshore waters. The most significant among them is the high-cost and energy-intensive nature of deep fishing that essentially involves reaching lower levels and trawling in deeper waters. The need for a prolonged stay in the oceans and the lack of bigger vessels capable of moving into distant waters are also major deterrents. Most fishermen own small- or medium-sized trawlers that are ill-equipped to operate beyond a depth of 250 metres. Lack of precise information on where to find the targeted fish,also hinders better exploitation of the deep sea. Such knowledge can help cut the cost and effort involved in deep-sea fishing substantially.
To remove this constraint, the task of locating commercially exploitable fishing grounds in the deep sea, has been taken up by Kochi-based Central Institute of Fisheries Technology (CIFT). It recently undertook a comprehensive study entitled "assessment of demersal fishery resources along the continental slope area of the Indian EEZ and the central Indian ocean". Involving cruises to far-off waters by a group of CIFT scientists, headed by U Sreedhar, on the fisheries and oceanographic research vessel Sagar Sampada, the study helped trace as many as 155 new fish species in water depths ranging from 50 to 1,100 metres.
"All the species spotted in this study were not known to exist in the Indian waters and thus are of great interest and possibly of great commercial value," maintains Sreedhar. "Some of these species figure in the list of threatened species compiled by the International Union for Conservation of Nature. Some others are among those whose conservation status is uncertain for want of adequate data," he points out. Further analysis of the biological composition and other traits of these species is underway at the CIFT headquarters. A major aim of these studies is to extract compounds from the species that may have nutritional, therapeutic or other gainful uses.
One of the discovered species, scientifically named Lamprogrammus, inhabiting deep-water columns at depths of 550 to 700 metres , is a fleshy fish that can be consumed as food. Another, Anoplogaster cornuta, found at depths of up to 2,000 metres, can serve as feed for tuna, albacore, marlin and others. Yet another species, Echinorhinus brucus, is a shark that is harmless to humans and can potentially be used for obtaining liver oil or preparing fishmeal.
Interestingly, this scientific mission also discovered Vampryoteuthis infernalis which, although called a "vampire squid", is actually a peculiar animal living between 600 to 900 metres. The high-pressure and low-oxygen content of water in that column is deemed unfavourable for life but the vampire squid manages to thrive there. This creature, notably, does not hunt but feeds like a scavenger on various kinds of remains floating in the sea. Another interesting find of this expedition was Synagrops japonicus that have light-emitting organs on their undersides. Once the precise commercial potential of these fish species is established through investigations, prospective entrepreneurs will be able to look for them at the locations suggested by the CIFT.
surinder.sud@gmail.com