Mactan, Kalawisan and Cansaga Bays
Location:	10°17'-10°23'N, 123°54'-124°02'E; on the east coast of Cebu Island north from Cebu City, and on the south and west shores of Mactan Island, Cebu Province.
Area:	18,000 ha including at least 3,800 ha of coral and sand flats, 350 ha of intertidal mudflats, 400 ha of mangrove swamps and 500 ha of fish ponds.
Altitude:	Sea level.
Biogeographical Province:	4.26.12.
Wetland type:	01, 02, 06, 07, 09 & 10.
Description of site:	A complex of shallow sea bays and channels, extensive intertidal sand flats and mudflats, mangrove swamps, fish ponds, salt pans and seaweed culture ponds, with coral reefs offshore. The area includes the mangroves, sand flats and fringing coral reefs of southern and western Mactan Island, the narrow Mactan Channel which separates the island from the Cebu mainland, the adjacent mainland coast (including Kalawisan Bay, Cansaga Bay and the estuary of the Cansaga River) with fringing mudflats and mangroves, and a large area of fish ponds at Jugan in Cansaga Bay. The tidal variation is l.8m, and there are strong tidal currents within the coral reef and Mactan Channel zones. Salinities range from brackish in the aquaculture ponds to hypersaline in the salt pans.
Climatic conditions:	Humid tropical climate with the seasons not very pronounced; relatively dry from November to April and wet for the remainder of the year (Type III). The site is partly sheltered from the northeast monsoon and trade winds, and open to the southwest monsoon or at least to frequent cyclonic storms.
Principal vegetation:	Mangrove forest dominated by Sonneratia alba in the sandier areas, and Avicennia marina in the muddier areas. Other mangrove species include Rhizophora mucronata (in rocky areas), Nypa fruticans, Lumnitzera racemosa, Excoecaria agallocha and Rhizophora apiculata. Non-mangrove species in drier areas include Sesuvium portulacastrum, Leucaena glauca, L. leucocephela, Bambusa blumeana and Glauca spp. Sea-grass beds are dominated by Thalassia spp and the seaweeds Turbinaria spp and Buergesinia spp. The seaweeds Caulerpa sp and Eucheuma sp are cultivated on a commercial scale in specially constructed ponds. There are plantations of Cocos nucifera and subsistence agricultural crops in adjacent areas.
Land tenure:	Most of the site is state owned but the greater part is leased to private individuals; surrounding areas are mostly privately owned.
Conservation measures taken:	Jugan Fish Ponds and adjacent areas important as roosting sites for shorebirds are protected by the owners. A part of Mactan Bay has been replanted with Rhizophora mangroves by the local inhabitants, and the sides of bunds in the Kalawisan area have been planted with Rhizophora to prevent erosion.
Conservation measures proposed:	A proposal has been made to introduce a complete ban on hunting in the area. Howes (1987) recommends that mangrove replanting and rehabilitation schemes be extended throughout the area, and that further conversion of mangroves into aquaculture ponds be terminated. Howes also recommends that further research be carried out on the importance of the site for waterfowl, and that the mangrove forest in Mactan Bay be used as an outdoor centre for education for local foresters and school and university students.
Land use:	Predominantly offshore fishing; also the harvesting of shellfish and mangrove products, navigation and outdoor recreation. Fish ponds at Jugan are used for the culture of milkfish (Chanos chanos) and prawns, while ponds in the Kalawisan region are used for the culture of the seaweeds Caulerpa racemosa and Eucheuma sp on a commercial scale. Nypa fruticans is used for the production of alcohol, and Rhizophora mangroves for the production of tannin. Surrounding areas are both rural and industrial, with a port complex and international airport.
Possible changes in land use:	There is a possibility of increased industrial activity in Cebu City and reclamation of intertidal areas for housing in Magellan Bay. Continued deforestation and the resulting soil erosion in the water catchment area may affect land use.
Disturbances and threats:	The principal threat is pollution from the Cebu Port and Industrial Zone, particularly the Shell Oil Terminal built on the coral reef on the south coast of Mactan Island. Pollution from the Asian Alchohol Plant at Cansaga Bay was particularly damaging to fish stocks, but this plant was closed down about ten years ago as a result of complaints from local fishermen. Other disturbances include heavy hunting pressure, particularly at Kalawisan, dynamite fishing and fish poisoning at Mactan and Kalawisan, and general over-exploitation of the marine resources.
Economic and social values:	The offshore fisheries are very important for the local economy and the Cebu market. The seaweed culture ponds provide a base for exports to Japan, and mangroves and nipa palms are harvested locally for construction purposes, tannin and animal fodder (leaves of Sonneratia and Avicennia spp).
Fauna:	One of the most important staging areas for migratory shorebirds in the Visayas. Up to 3,700 shorebirds were observed at Jugan Fish Ponds in 1986, and almost 1,600 were observed in the area in April 1987. Twenty-three species were recorded, the commonest being Pluvialis dominica, Charadrius mongolus, Tringa totanus, T. nebularia, Actitis hypoleucos, Heteroscelus brevipes (710 in April 1987) and Calidris ruficollis (maximum of 2,600 in 1986). The area is also important for a variety of herons and egrets, including the endangered Chinese Egret Egretta eulophotes, 17 of which were observed on the sand flats of southern Mactan in April 1987. Terns (Sterna spp) are common, and several species of ducks including Anas clypeala and Aythya fuligula have been recorded at Jugan Fish Ponds. Fishes include Mugil spp and Siganus sp.
Special floral values:	Magellan Bay and Cansaga Bay on southern Mactan support small pockets of mature Sonneratia/Avicennia type mangrove forest.
Research and facilities:	Magsalay conducted regular monthly counts of shorebirds at Jugan Fish Ponds in 1986, and the Asian Wetland Bureau carried out a wetland evaluation of the area in April 1987 (Howes, 1987). The University of San Carlos in Cebu City has a marine research station off Mactan Island, concerned mainly with research on coral reefs.
References:	Howes (1987); Parish (1987); Magsalay (in press).
Criteria for inclusion:	1b. 1e, 2a, 2c, 3b.
Source:	John R. Howes and Perla M. Magsalay.