| Mangrove forests are generally distributed in the inter-tidal areas between the land and the sea in the tropical and subtropical regions of the world. The Pacific region is an area with thousands of islands that are home to mangrove forests that are highly diverse in their spatial extent as well as taxonomy. The nineteen Pacific islands in the study region represent this diversity. However, the spatial extent of the Pacific mangrove forests is not known on a regional scale. While the mangrove forests of some of the larger islands such as Papua New Guinea, New Caledonia and Fiji have been well documented, many of the smaller islands do not have reliable estimates. The available estimates of mangrove forests for the Pacific region are often outdated, incomprehensive and incompatible. A regional assessment based on a scientific methodology is needed to understand their true extent. This research offers a regionally consistent, moderate resolution (30m) and a comprehensive mapping of mangrove forests on the islands of American Samoa, Fiji, French Polynesia, Guam, Hawai'i, Kiribati, Marshall Islands, Micronesia, Nauru, New Caledonia, Northern Mariana Islands, Palau, Papua New Guinea, Samoa, Solomon Islands, Tonga, Tuvalu, Vanuatu and Wallis and Futuna Islands for circa 2000. The mangrove forests areas were mapped using unsupervised image classification technique on a total of 128 Landsat scenes gathered between 1999 and 2004, and the results were validated using existing GIS datasets, high resolution imagery and published literature. Furthermore, a comparative analysis is drawn with the mangrove forests inventory published by The United Nations Food and Agriculture Association (FAO) for the year 2000. This analysis shows a total of approximately 62, 3755 hectares of mangrove forests in the Pacific region; an increase of 17.9% from FAO's estimates. Although mangrove forests are disproportionately distributed on a few larger islands on the western Pacific, they are also present in many smaller islands. |
