World's mangroves retreating at alarming rate-study

The world's mangroves are being destroyed up to four times faster than other forests, costing millions of dollars in losses in areas such as fisheries and storm protection, a report said on Wednesday.

The study commissioned by the United Nations Environment Programme (UNEP) and The Nature Conservancy said a fifth of mangroves had been lost since 1980 and that they continued to be destroyed at a rate of around 0.7% a year by activities such as coastal construction and shrimp farming.

The ''World Mangrove Atlas'' report noted that mangrove forests provide huge economic services, acting as nurseries for sea fish, storing carbon and providing robust defences against floods and cyclones at a time of rising sea levels.

The trees and shrubs, which grow in saline coastal habitats, also provide excellent rot-resistant wood. 

"Given their value, there can be no justification for further mangrove loss," said Emmanuel Ze Meka, head of the International Tropical Timber Organisation, which helped fund the report.

The report cited evidence that mangroves reduced the impact of the 2004 Indian Ocean tsunami in some places. 

It urged nations, especially those with the largest mangroves like Brazil, Indonesia and and Australia, to do more to halt the retreat of an estimated 150,000 square kilometres of global mangrove forest cover.

"The greatest drivers for mangrove forest loss are direct conversion to aquaculture, agriculture and urban land uses. Coastal zones are often densely populated and pressure for land intense. Where mangroves remain, they have often been degraded through overharvesting," it found.

It cited Malaysia as a country that uses state-ownership of mangroves to better manage them and stem their decline.