Mactan, Kalawisan and Cansaga Bays (9770)
Philippines, Asia
Site overview
KBA status: confirmed
Global KBA criteria: D1a
Year of last assessment: 2006
National site name: Mactan, Kalawisan and Cansaga Bays
Central coordinates: Latitude: 10.3333, Longitude: 123.9667
System: marine, terrestrial
Area of KBA (km2): 63.7312
KBA classification: Global
Legacy site: Yes
Site details
Site description: This IBA includes a complex of shallow sea bays and channels, extensive intertidal sand flats and mudflats, mangrove swamps, fishponds, 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 total area of 18,000 ha includes 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. The surrounding areas are both rural and industrial, with a port complex and international airport, and associated industrial complexes and oil terminals. There are also coconut plantations and subsistence agricultural crops in the rural areas. 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.). Gleaning on the intertidal flats is also very important for the local communities.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that meets the thresholds for at least one criterion described in the Global Standard for the Identification of KBAs. KBA identified in the CI/CEPF Conservation Outcomes booklet for the Philippines Hotspot (2006). Taxonomy, nomenclature and threat category follow the 2004 IUCN Red List.
Additional biodiversity: This IBA is 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 (of 23 species) were observed in the area in April 1987, including internationally important numbers of Grey-tailed Tattler. The area is also important for a variety of herons and egrets, including the threatened Chinese Egret. Terns (Sterna sp.) are common, and several species of ducks have been recorded at Jugan Fish Ponds.
Habitats
Summary of habitats in KBA: This IBA includes a complex of shallow sea bays and channels, extensive intertidal sand flats and mudflats, mangrove swamps, fishponds, 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 total area of 18,000 ha includes 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. The surrounding areas are both rural and industrial, with a port complex and international airport, and associated industrial complexes and oil terminals. There are also coconut plantations and subsistence agricultural crops in the rural areas. 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.). Gleaning on the intertidal flats is also very important for the local communities.
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Artificial - Aquatic | 3 | |
| Marine Neritic | 29 | |
| Marine Intertidal | 23 | |
| Marine Coastal/Supratidal | 29 | |
| Artificial - Terrestrial | 14 | |
| Forest | 2 |
Threats
Summary of threats to biodiversity at KBA: The principal threat to this IBA 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. There is also a possibility of increased industrial activity in Cebu City and the reclamation of intertidal areas for housing in Magellan Bay. A coastal resort has recently been developed on Mactan Island for tourists. Jugan Fish Ponds and adjacent areas, which are important roosting sites for shorebirds are protected by the owners. However, there is heavy hunting pressure elsewhere, particularly at Kalawisan, dynamite fishing and fish poisoning at Mactan and Kalawisan, and general over exploitation of the marine resources. A proposal has been made to introduce a complete ban on hunting in the area. Continued clearance of mangroves and the resulting soil erosion in the water catchment area may affect land use. The local inhabitants have replanted part of Mactan Bay with Rhizophora mangroves, and the sides of ponds in the Kalawisan area have been planted with Rhizophora to prevent erosion. There is probably some conflict between the operation of Cebu airport and the presence of large concentrations of birds near the airport runway. Control measures used to deter birds from frequenting the runways include the use of scarecrows, flags, explosives and other sound repellents, and even traps or shooting.
Additional information
References: Davies et al. (1990); Scott (1989).