The island group of Siargao (coordinates: 9° 52’ N, 126° 03’ E) is a complex of over 50 islands, islets, reefs, and atolls, of which the islands of Siargao and Bucas are the largest and the most populated. It is located northeast of Mindanao and east of Dinagat Islands, between Dinagat Sound and the Pacific Ocean. Siargao falls under the political jurisdiction of Siargao del Norte, Province and is comprised of nine municipalities under the province’s first district, namely, Burgos, Dapa, Del Carmen, General Luna, San Benito, Pilar, San Isidro, Santa Monica, and Socorro and with a total of 132 barangays. In territory size, the largest is Del Carmen (with 20,189 hectares) and the smallest is Burgos (1,905 hectares). The island group of Siargao is a protected area and is collectively known as Siargao Island Protected Landscape and Seascape (SIPLAS).

Siargao island group occupies an area of 62,796 hectares. Terrain is generally rugged and mountainous with numerous low hills and mountain ranges that straddle the islands, but none of which reach heights of no more that 300 meters. The basal rocks of Siargao and adjacent islands are composed of limestone karst. The soil type of Bucas Island and adjoining islands is ultramafic and is rich in mineral ores. In contrast to other surrounding islands (such as Dinagat and nearby islands), the islands of Siargao have not been strip-mined for precious metals.

Many of the islands in the Siargao group, especially the low-lying hills and mountain ranges, are still covered with sizeable tracts of various types of forest: forest over limestone karst, forest over ultramafic rocks, beach forest, and mangrove forest. Mangroves are especially extensive at the western region of Siargao at the Municipality of Del Carmen; smaller tracts occur at inland bays of Siargao, Bucas, and adjacent smaller islands. This type of habitat is among the most threatened in the Philippines and has greatly declined in the area. This makes Siargao one of the most important areas in the Philippines in terms of biodiversity conservation of mangroves.

SIPLAS is one of the key biodiversity areas of the Philippines and was declared as a protected area by virtue of Presidential Proclamation 902 in October 1996. Its marine and terrestrial biodiversity, however, remains poorly studied. For instance, no major biological expedition to survey the region’s terrestrial biodiversity has been undertaken since the early 1970’s. A series of surveys of the marine biodiversity of Siargao was conducted in the late 1990’s but were limited to a few sites.

We propose to conduct biological field surveys at 5-10 sites across the mangrove forests of Del Carmen of Siargao Island in order to assess the degree of diversity and abundance of flora (phytoplankton, marine algae, seagrass, flowering plants) and fauna (zooplankton, crustaceans, marine fish, amphibians, reptiles, birds, mammals).

Studies on these groups will center on qualitative and quantitative description and analysis of patterns of species richness, abundance, distribution, and habitat preferences. By generating this scientific information, this project will directly support efforts by the local government office of the Municipality of Del Carmen, Siargao, and of the Province of Surigao del Norte to have the mangrove ecosystem in the Municipality of Del Carmen be recognized as a wetland of international importance as one of the Ramsar sites in the world.

This project will directly support efforts by the local government of Del Carmen and the Province of Surigao del Norte to the Siargao Island impact future conservation efforts in the Philippines and will provide unique insights into patterns of distribution, abundance, species richness, and dispersal abilities across a diverse group of vertebrates.