Philippines floor is covered with sandy mud or soft mud (Pichon, 1977a). Numerous islets are found on the bank, including Pandanon Islet, the two Caubyan Islets on the outer barrier, Tood Islets at the east end of the bank, and Danajon Islet. These are low, small, wooded, and covered with bushes (MPRDP, 1982a). Minantao Reef is a small patch reef lying within the double barrier reef (Hodgson and Ross, 1981). The Danajon Bank is weu protected from intense hydrodynamic action due to the enclosed location of the Camotes Sea. It has been suggested that the double barrier developed through unique tidal currents andor resumption of subsidence after the outer barrier was formed (Pichon, 1977a). Grobe et at. (1985) studied the double barrier. Reef Structure and Corals The outer slope of the outer barrier generally has a gentle upper slope about 500-800 m wide down to a 15 m depth and a lower, vertical slope down to 50 m. The upper slope has about 50% coral cover with Pavona cactus and Aiacropora dominating. Fungiids are particularly abundant on hard and soft bottoms and include species such as Halomiira phili pinensis The lower drop-off is composed of horizontal overhangs where Leptoseris dominates. Ahermatypic forms, like Tubastrea and Dendrophyllia, occur under the overhangs (Pichon, 1977a). commercially valuable red alga Eucheuma spinosum, a source of carageenan, was set up on the north-western bank in 1975. By 1979, there were 200 farm housesplatforms constructed, 500 hectares planted, 15 million plants in the water, 2000 people working daily in the farms, and 8000 people or 1000 famihes Using on the banks fully or partly dependent on income from farming seaweeds. It is being studied as possible seedstock for numerous Eucheuma farms on the reef flats of the western outer barriers (Lim and Porse, 1981). Disturbance or Deficiencies The area is subject to considerable damage from illegal fishing, especially dynamite fishing. Coral gathering was common before the 1977 ban (MPRDP, 1982a). The immigration of sea farm workers onto the banks and the seaweed farming activities may add to the disturbance of the area. Legal Protection None. Management None. Recommendations Danajon Bank has been included in the list of candidate marine park or reserve sites (MPRDP, 1982a and 1983). It has recently been proposed as a reserve by the NAME and is considered a priority site but as yet has received no management (White m to, 30187). The reef flats of both inner and outer barriers are similar. The external part of the reef flat on the outer barrier is covered mainly with corals of various growth forms (massive, digitate, or branching). The seagrass beds of both barriers are often interrupted by sandy areas where acroporids, pocilloporids, faviids, and Millepora grow (Pichon, 1977a). The back-reefs of both barriers are composed of sandy slopes colonized by large coral heads. The back-reef of the outer barrier has indented coral-built margins, sometimes descending by a series of steps toward the lagoon floor and colonized mostly by Anacropora, Pontes, Echinopora, Pachyseris, and Pectinia (Pichon, 1977a). Hodgson and Ross (1981) describe corals collected at Minantao Reef. Noteworthy Fauna and Flora The drop-off on the outer barrier has large reef-dwelling fish and occasional rays and sharks may be seen (Smith et ai, 1982). Alcyonarians, Sarcophyton and Xenia, are particularly abundant on the outer slope. The seagrass beds are dominated by Thalassia hemprichi and Enhalus acoroides (Pichon, 1977a). Scientific Importance and Research Danajon Bank is famous for its unusual double barrier reef morphology. Pichon (1977a) gave a detailed description of the area and concluded that the present structure can be interpreted as being an example of a degraded stage (by hyperaccumulation of sediments) of the coral reef evolutionary series. In 198081, the double barrier was studied by a group from the University of Kiel, West Germany, in cooperation with the University of San Carlos, Cebu (Wefer, 1985). The area has been surveyed by the BFAR as a candidate site for a marine reserve (MPRDP, 1982a). Economic Value and Social Benefits Fishermen from Romblon, Mindoro and Marinduque regularly fish these waters. Aquarium fish collecting has been reported (MPRDP, 1982a). An experimental farm for the DOS HERMANAS Geographical Location 12-15 nautical miles (22-28 km) south of Gasan, Marinduque Island; under the municipal jurisdiction of Corcuera (Jones), Romblon, located to the south-east; 131N, 12154E. Area, Depth, Altitude Total area of islands 45 ha; maximum altitude is 70 m (Isabel Island); maximum depth of fringing reefs 30 metres. Land Tenure Government-owned. Physical Features Dos Hermanas is a pair of islands two nautical miles (37 km) apart, oriented east-wst. The larger westernmost island is Carlota; the other is Isabel. Both islands are flat-topped with coastal limestone cliffs approximately 30-40 feet (9-12 m) high (MPRPD, 1983). Carlota has a short strip of beach on the north-east. Both islands are sparsely covered with Cogon Imperata and scrub. Carlota has a cultivated area, adjacent to the beach, planted with com, cassava and bamboo. The substrate is clay mixed with pebbles and coralline materials. The cliffs on both islands are almost vertical and are pock-marked with caves and crevices. Visibility underwater is 100' (30 m). Reef Structure and Corals Carlota Island is bordered by a fringing reef which is steeply sloping except on the north side, where the island has a rocky beach and the reef slopes gently down to 20 fathoms (36 m). Isabel Island is ringed by a narrow fringing reef on all sides. At a distance of one to two kilometres on the south and south-west of both islands are reef patches and white sand that slope gradually (NEPAL, 1977; MPRPD, 1983). -245