The first ever assessment of mangrove species by the IUCN Red List found 11 out of 70 mangrove species threatened with extinction, including two which were listed as Critically Endangered. Threats include coastal development, logging, agriculture, and climate change.

Species were evaluated by mangrove specialists and the Global Marine Species Assessment Unit (GMSA), a joint venture between the IUCN and Conservation International.

"The potential loss of these species is a symptom of widespread destruction and exploitation of mangrove forests," says Beth Polidoro, Research Associate of the GMSA at Old Dominion University and lead author of the study appearing in PLoS ONE. "Mangroves form one of the most important tropical habitats that support many species, and their loss can affect marine and terrestrial biodiversity much more widely."

Present in tropical and subtropical regions, mangroves grow where salt water meets the land. Although depleted in many parts of the world, mangrove forests provide vital ecosystem functions. The forests serve as nurseries for a variety of fish and other marine species and act as buffers against erosion. They also have the ability to store large amounts of carbon from the atmosphere. Finally, recent studies have shown that mangroves save both property and lives in the face of fierce tropical storms. During the devastating 2004 tsunami in Southeast Asia, regions with mangroves suffered less damage than those without. In all it is estimated that mangroves provide at least 1.6 billion US dollars in ecosystem services annually, yet despite their importance society is failing to stem the massive loss of mangrove forests worldwide.

"The loss of mangroves will have devastating economic and environmental consequences," explains Greg Stone, senior vice president of marine programs at Conservation International. "These ecosystems are not only a vital component in efforts to fight climate change, but they also protect some of the world’s most vulnerable people from extreme weather and provide them with a source of food and income."

Southeast Asia is home to both of the Critically Endangered species located by the study: Sonneratia griffithii and Bruguiera hainesii. Researchers have estimated that in the past 60 years Southeast Asia has lost 80 percent of its mangrove ecosystems, putting species like Sonneratia griffithii and Bruguiera hainesii at grave risk: to date only 250 mature Bruguiera hainesii survive.

By Jeremy Hance