A study was conducted by the Pacific Southwest and Northern research stations of United States Forest Service, University of Helsinki in Finland, and the Indonesian based Center for International Forestry Research.

It assessed the carbon content of 25 mangrove sites on the shores of the Indian and the Pacific Oceans. The mangrove systems were found to keep four to five times more carbon than terrestrial forests, due in part to their thick layer of organic-rich sedimentary soil.

Our thankfulness, all scientists involved, for these important results. May we do everything possible to protect this invaluable treasure of our ecosphere.
http://www.sciencedaily.com/releases/2011/04/110404173247.htm
http://www.nature.com/news/2011/110403/full/news.2011.205.html