15
January
2016
|
00:58
Asia/Singapore

Whither our mangroves

Mangrove forests in Southeast Asia are being depleted at an average rate of 0.18 per cent per year, with aquaculture, the expansion of rice production and oil palm plantations as the main causes. These findings were published by Assistant Professor Daniel Friess from NUS Geography, together with Dr Daniel Richards from the University of Sheffield, UK, in Proceedings of the National Academy of Sciences of the United States of America in December 2015. Dr Richards was formerly with NUS Geography.

“This is the first study to systematically quantify the conversion of mangroves to different land use types in Southeast Asia and identify the key drivers of mangrove deforestation over the last decade. While the available data potentially show encouraging signs of a slowdown in mangrove deforestation, it is important to note that mangrove loss in Southeast Asia still remains substantial. This not only results in negative impacts on the mangrove diversity, but also undermines the ecosystem services that mangrove forests provide, such as carbon storage,” said Asst Prof Friess.

The research team found that almost 10,000 hectares of mangroves were lost per year from 2000 to 2012, with the Rakhine state in Myanmar, Sumatra, Indonesian Borneo and Malaysia seeing higher rates of deforestation.

Aquaculture — the farming of edible aquatic plants and organisms including crustaceans and fish — was the leading cause of mangrove deforestation in Southeast Asia, particularly in Indonesia, the Philippines, Brunei, Cambodia and Vietnam. In Indonesia, aquaculture resulted in almost half of the country’s mangrove loss over the 12-year period.

An increase in rice production across Myanmar, predominantly in the state of Rakhine, accounted for more than 20 per cent of the total mangroves lost during the study period. The agricultural expansion was likely an effort by the government to enhance national food security. The researchers suggested that economic diversification from rice to products such as shrimp and oil palm could occur as export restrictions are reduced in the future.

The third largest driver of mangrove deforestation was attributed to oil palm plantations, primarily in Sumatra and Borneo in Indonesia, and Malaysia. This is in line with the countries’ standing as top palm oil producers; and together, they produce 85 per cent of the world’s palm oil.

mangrove 2

An aerial view of mangroves in West Papua, Indonesia

Besides having the greatest diversity of mangrove species, Southeast Asia houses one-third of the world’s mangrove forests. The reduction of mangroves is a cause for concern, as they also store substantially higher densities of carbon, when compared to other ecosystems, thus playing a significant role in absorbing carbon emissions and mitigating the effects of climate change.

See press release and media coverage.