Net disaster

  • 14/08/1999

In Japan, boys and young men practice what is called the muro-ami fishing technique. Using rocks tied to "scarelines' that are flagged with brightly-coloured streamers, they swim together over the reef and pound on its ridges. This scares the fish living inside the reef crevices, and as they come out the streamers lead them into a semi-circular net known as a muro-ami.

In the Philippines, some fishing communities pour drums of sodium cyanide to temporarily asphyxiate the reef fish. As they float to the sea surface, they are easily netted by their captors.

Probably the worst method used in the Indo-Pacific region is to toss dynamite into schools of reef fish. The force of the explosion ruptures the air bladders that control buoyancy in fishes. The fisherfolk easily harvest the injured fish that float to the surface. Dead or mangled ones and commercially undesirable species are left behind. "Stretches of fishless reefs around the Tanzanian island of Zanzibar, for example, are riddled with holes from the blasting, some as big as 10 metres in diameter,' says Barbie Bischof in The Yearbook of Science and the Future 1999 .

These are just some of the destructive fishing techniques practised the world over. Though reefs occupy only about 0.2 per cent of the world's oceans, they provide an estimated 10 per cent of all the fish harvested worldwide, says Bischof.

The dependence on reefs as a means of human sustenance has put added pressure on them. And what has worried coral watchers is the growing trend among people, especially in the Asian countries, to cater to the seafood market, even if it means using destructive fishing practices. "Fishing operations are today spreading to remote areas. Because of the disappearance of large fish in the populated Asian continent, fishing companies are willing to travel even to the South Pacific islands... Because of the high cost of transportation, commercial fleets are harvesting in one sweep, rather than engaging in a sustainable practice that entails smaller hauls and repeated visits,' says Bischof. This has resulted in the disappearance of large fish species in some areas. The jewfish, which is of great commercial value in the Caribbean, has virtually disappeared, from the region's reefs.

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