Taking ecology to the seas

A FEW years ago, I visited Orissa to see the turtles nesting on the beaches of Gahirmatha, Rushikulya and Ekkakulnnai. Then, unlike now, very few turtles came to nest. What I saw, however, was a graveyard. The mangled remains of turtles caught in the fishing nets of the big trawlers were sprinkled across the sands and stray dogs were making a meal of them. For a nature lover, it was a heart-rending sight.

Last month on a visit to the Central Institute of Fisheries Technology (CIFT) at Kochi, I was delighted to see the turtle excluder device (TED) designed by the Institute. The TED is now seen as vital for responsible fishing. Fishermen, who wanted to catch all that they could in one clean scoop of the sea bed, were unhappy with the bigger TEDs which allowed shrimps and smaller fish also to escape with the turtles. After trial and error, an 800 by 1000 mm oval-grid TED has been designed. It is a top exiting single-grid hard TED meant for use in small mechanised trawlers in Indian waters. Five vertical grid bars of 8 mm diameter steel rods are welded inside of the frame with a spacing of 150 mm. The TED frame is fixed at an angle of 45 inside the TED extension cylinder made of polyethyelene netting. TED extension is provided with an exit of standard dimensions on the upper side with a cover or flap. An accelerator funnel is incorporated in the design for reducing the shrimp loss.

When this device was tried out at Visakhapatnam, 90 per cent of the turtles were able to escape. In February, at the invitation of Orissa Fisheries Directorate, CIFT scientists demonstrated the fabrication and operation of TED to local fishermen, net makers, entrepreneurs, environmentalists and others. Trawler fishermen had expressed concern about the large-scale loss of shrimp and fish because of TEDs. The new devices with exit cover codend, reduced the loss of shrimp to 0.62 per cent and overall loss of total catch to 1.2 per cent. All the Olive Ridley turtles which entered the nets during the operations, off Agaranasi, Paradeep, escaped. Some of them weighed 50 kg. The Marine Products Export Development Authority has ordered 600 TEDs.

In a small trawler, the TED can handle one to nine tonnes of fish. The trawler, cruising at three nautical miles an hour, catches the fish. Before the use of TEDs, shrimp trawlers were killing around 11,000 sea turtles in the Gulf of Mexico and along the South Atlantic coast annually. Now with the use of TEDs and an effective conservation strategy, there is hope of saving the turtle population for posterity. In Gahirmatha, which is one of the world's bigger nesting sites for the Olive Ridley, environmentalists and the Wildlife Institute of India have been pleading for the use of TEDs for some years now. Fortunately, the ecological concerns voiced in India found support in the United States which threatened to stop shrimp imports from India unless the fishing boats used TEDs.

According to Dr. K. Devadasan, director of the CIFT, of the $1100 million (Rs. 46300 million) marine exports from India, shrimp accounted for 72 per cent. Now that a fairly efficient TED is available, an all out effort has to be made to ensure that fishermen use it every time they set out.

In its own quiet way, CIFT has been safeguarding the ecological concerns of the nation through development of TEDs and utilisation of fish waste. Dr. Devadasan said that development of responsible fish harvesting techniques and viable post-harvest methods was the focus of the Institute's research in 1999-2000. The most significant achievement was the design and construction of a 15.5m fuel-efficient steel fishing vessel, Sagarkripa.

With the help of the Space Application Centre, Ahmedabad, the Institute has been using satellite imagery to locate potential fishing zones. Fishing boats, made from treated rubber wood and other less expensive woods, were manufactured. Eco-friendly fishing methods such as V-form otter board and by-catch reduction device were popularised.

The fishing industry brings Rs. 6,000 crores of foreign exchange into the country and half the catch is from Kerala alone. The southern coastline is a highly productive area. Earlier, prawn and shrimp formed the bulk of fish exports. Now other fish are being caught and value additions made.

The octopus, found in abundance on the east coast, is processed and exported, jellyfish is semi-dried and exported to the Far East. Squid and turtle fish are considered delicates in Japan. Shark, caught off the coast of Saurashtra, is like a coconut tree - every part of it is used.

Waste from the fish catches is now being put to good use. More than 100,000 tonnes of prawn and other crustacean shell waste is available annually from the processing centres. CIFT has developed a process for preparation of chitin from this shell waste. Incorporated in the diet of broiler chicks, chitin increases the weight of the chicks by 10 to 12 per cent. Chitin is also used for the production of glucosamine hydrochloride used in antibiotics and baby food formulations.

From prawn shell waste, a chemical called chitosan has been produced. This is used as a water and wine-clarifying agent and also in preparation of cosmetics and pharmaceutical products. Micro-fine chitosan powder, impregnated in gauze and films, helps treatment of chronic wounds and external ulcers. It also minimises bleeding in neurosurgery. From fishery wastes, chitin film is prepared to serve as artificial skin over wounds and burns. This artificial skin prevents moisture loss from burns as well as microbial invasion.

Till recently, shark bone was used in limited quantities to make necklaces and buttons. Now the cartilaginous bone is used in medicines for treatment of arterosclerosis and blood vessel thrombosis. Processed shark bone is in demand in Europe, the U.S. and Australia. CIFT has developed a process for extracting the shark fin rays used in soups in many foreign countries.

Till now cat guts were used as absorbable sutures during surgery. Now CIFT has processed fish guts as surgical sutures. Fish gut sutures are not only cheaper but can also be better utilised. It has been found suitable for eye and other micro-surgery.

CIFT has also entered the fish packaging business in a big way. Based on consultancies from the industry, it has developed packaging for fish curry, dried fish (sans smell), fried mussel ... For cutlets made from fish meat, it has developed thermoform containers. The fish processing division is helping industry can and export tuna, mackrel, clams, smoked fish, sardines, oysters and mussel. The environment-friendly CIFT is now working on biodegradable plastic packaging.

USHA RAI

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