The direct result of the expansion of these fisheries has been the death of tens of thousands of small cetaceans in Sri Lankan waters. Many of these are entangled accidentally in coastal gill nets set to catch fish such as tuna and sharks, and others are taken by a large-scale commercial fishery which kills dolphins deliberately for use as bait.
In the past, dolphins were sometime accidentally entangled in fishing nets in Sri Lanka's coastal waters. However, the nets were made of natural fibre such as jute and cotton and the dolphins could either detect them with their sonar or break free if they did become entangled.
Then, as part of an extensive programme funded by the UN Food and Agriculture Organization (FAO), designed to encourage the modernization of Sri Lanka's fisheries, nets were supplied that are made of stronger materials, which the dolphins can neither detect nor break. These gill nets are now being used, in some areas, to catch dolphins deliberately and a market for cetacean meat, which did not exist prior to the FAO net programme, has now developed.
Conservationists are concerned that the total catch may be extremely high. Interviews with fishermen from Tangalle, in the south of the island, suggest that they generally take 10-25 dolphins a day in gill nets between March and July each year; if true, this would amount to an annual icidental kill of between 1,800 and 4,500 dolphins by fishermen from this one town alone.
A report written by marine mammal scientists Stephen Leatherwood and Randall R. Reeves (based on studies by Abigail Alling in conjunction with the Sri Lankan National Aquatic Research Agency [NARA]), was published in 1990 by the United Nations Environment Programme (UNEP). This estimated that between 25,000 and 45,000 small cetaceans may be brought ashore every year having been killed, deliberately or accidentally, in Sri Lankan waters. It isn't known how many dolphins are killed and used as bait at sea, although NARA had previously estimated that bait fisheries were responsible for 25 per cent of the total dolphin kill in the area.
Tragically, the size of this catch is likely to increase as the market for dolphin meat grows and the commercial fisheries in the region continue to expand, creating an increased demand for bait. At the same time, dolphins are being killed by harpoons fired from 3.5-tonne ships in some areas when catches of the usual target fish are poor. With the decline of fish stocks, particularly tuna, the number of dolphins being taken is likely to grow.
The Sri Lankan fishery is a case study in how well-intentioned programmes can have unforeseen and damaging effects. It is a difficult situation to tackle, given the enormous financial incentives for fishermen to modernize and eexpand their operations. Any efforts to conserve marine mammals, or for that matter fish stocks, in Sri Lankan waters will understandably meet with strong local opposition. Consideration has to be paid to the interests of those may Sri Lankans for whom the sea's resources may provide their best, if not their only, means of securing a better standard of living. A programme, jointly sponsored by UNEP and NARA, is currently working to educate fishing communities about the problems of over-exploitation.
Effective regulations of fishing gear, seasons and areas could enable fisheries and dolphins to co-exist in Sri Lankan waters. However, fishermen, scientists and environmentalists must strengthen their co-operative efforts to ensure that these regulations are developed and implmented in the interests of all.