VOA标准英语2010年-Sierra Leone Working to Save Mangrove（在线收听）

Sierra Leone is working to preserve the ecosystem of coastal mangrove swamps that are threatened by people collecting firewood and harvesting salt.

Harvesting salt along the coast of West Africa is an age-old business. But today  conservationists say it is degrading mangrove swamps and ravaging fish stocks.

Lawmakers in Sierra Leone are preparing to join a seven-nation charter to protect the region's mangrove ecosystem which conservationists now say totals just 800,000 hectares.

Mangroves are the most readily available source of firewood for fires to boil seawater and what is called "salt dust" scraped from the soil.

Marie Kano heads Sierra Leone's salt producers' association. She says many of the mangrove trees used for fuel are already gone.

"We come here to scrape the salt and we collect the salt dust," she said. "But because there is no wood, we've left the salt business for other things. My children, my sister and my father lived with me and we all used to cook salt. But because there is no wood anymore, they all left and went to town."

Environmentalists are trying to encourage Sierra Leone's salt producers to use other methods, including drying salt in the sun, to reduce the strain on mangroves.

"If the mangroves disappear, fishing will be in crisis and the ecological balance will be disrupted," said Richard Dacosta, the West Africa coordinator for the development group Wetlands International. "Also the saltwater tide will invade river estuaries and coastal areas. And local communities, who usually live right on the coast, will have to move."

West Africa's mangrove forests absorb thousands of tons of carbon dioxide, and could be a way for the region to get a foothold in the $136 billion carbon world market.

They are the nurseries of the ocean, where many species of fish and shrimp breed and serve as a buffer against coastal erosion in a region where much of the population lives in low-lying areas.