This is not just a problem of local exploitation. Ever greater numbers of fishermen are coming to the islands' rich fishing grounds from Dar-es-Salaam, capital of Tanzania, of which Zanzibar is now part. These fishermen maximize catches with such destructive methods as dynamite fishing and trawling nets, which often rip out the corals.
Such is the danger that the Zanzibar government approached the conservation organization, WWF, with a plea from 14 villages on Menai Bay for help in protecting their traditional fishing grounds. The bay, which covers 470 square kilometres, is on Unguja island, not far from the capital, Stone Town. It is still largely intact, with extensive coral reefs, fields of sea grass and mangrove forests.
WWF-Switzerland agreed to finance the project and provide technical support, with the aim of protecting the bay through management by the local fishermen and the development of varied and sustainable cultivation. In 1995, the Zanzibar Marine Institute was commissioned to carry out a study of the ecological and economic importance of Menai Bay, while WWF held discussions with representatives from the 14 villages.
Winley Sichone, the WWF's local Project Director, recalls: "Our main task was to define the boundaries of the protected zone. Of course, the fishermen were afraid. But although there are some restrictions in the protected zone, fishing is allowed to continue there." As well as changing the work patterns of the local fishermen, the WWF management plan for the bay requires monitoring to prevent illegal fishing.
Patrol leader Nassoro Regebu says: "Thanks to the radio sets provided by the WWF, the village communities can communicate with one another, as well as with the authorities and the patrols. If we stop illegal fishermen in Menai Bay, we first point out to them that they are present without authority. We have no police powers, but we are authorized to report offending fishermen to the authorities, who will then open criminal proceedings."
Monica Borner, who has responsibility for International Projects at WWF-Switzerland and who has herself lived in Zanzibar, believes the programme is working well.
She says: "The government has passed laws that transfer the right of administering and exploiting the protected zone to the inhabitants of the villages. Fisheries Department officials and police help to make sure these laws are enforced."
There have also been welcome changes in the way the fishing communities earn their living, Borner says. "The individual fishermen had few possibilities of selling their catches in the town, because it was too far away and the quantities were too small. Now, marketing is coordinated, with catches deep-frozen in the villages' own freezer plant. Then they are taken to the city for sale in larger consignments."
But fishing does not provide a living for everyone. Round the bay, with its extensive coastal forests, certain land areas are totally protected while others are cultivated. That still means the locals must seek new sources of income if they are to improve their quality of life. One possibility is sustainable tourism, Borner says: "People can earn an additional income as guides and pilots, by hiring out boats, or from small restaurants."
Such is the support in Zanzibar for the Menai Bay project that it has recently become Africa's first "Gift to the Earth", an award presented to celebrate its achievements as part of WWF's Living Planet Campaign. The lesson is that people can protect their environment even as they make use of it.
*Richard Lehner is Director of Communications at WWF-Switzerland