Philippines

Spalding et al. (2001) place the Philippines, with Indonesia, at the center of global coral reef biodiversity, and estimate the country's reef area at 25,060 km², with 421 coral species recorded and 577 estimated for its biogeographic region. The three areas on this page are very different parts of it. Around Luzon they found reefs far from continuous, with none in the far northwest, the first fringing reefs at the Hundred Islands in the Lingayen Gulf, and discontinuous fringing reefs in the south, notably at Puerto Galera on Mindoro; ash and mudflows from the Mount Pinatubo eruption cut live coral cover on the nearest fringing reefs from 60-70% to 10-20%. Palawan's reefs they rank among the most fully developed in the country, with fringing and patch reefs along most of its coast, live cover reported at 50-90% in places, offshore banks thought to belong to a long submerged barrier reef, and the two atoll systems of the Cagayan Islands and Tubbataha in the Sulu Sea. The Visayas are a close-set group of islands around the Visayan Sea, fringed along much of their coast and broken by soft sediment near river mouths, and home to the small reserves at Apo Island and Sumilon, cited as globally recognized models of community-based management. The same account rated 97% of the country's reefs as at risk from human activity.

This page covers 26 sites in three regional groups, from three separate trips. The Visayas group holds seven sites from recreational dives in February 2013 around Moalboal and Pescador Island off western Cebu, Mactan Island beside Cebu City, Alona Beach on Panglao and Balicasag Island off Bohol, Apo Island off Negros, Punta Ballo at Sipalay, and Boracay. Luzon holds seven dived on 30 September and 1 October 2016, four around Anilao and three in the Verde Island Passage. Palawan holds twelve visited between 20 and 28 January 2017 in three areas: Port Barton, the Bacuit Archipelago off El Nido, and Busuanga and Coron Island. Logged maximum depths, where they exist, ran from 12.8 m on the Anilao night dive to 34.4 m on the Akitsushima wreck at Coron. The record is unevenly built: the Visayas sites rest on Anderson's dive logs alone, because every surviving frame from that trip is topside, while the Luzon and Palawan sites have photographs and photo-derived cover.

Blind Claude computer-vision cover exists for 15 of the 26 sites and averaged 26%, from 4.6% at Beatriz Island to 67% at the first Port Barton island-hopping stop. Palawan averaged 33% (n = 9) and Luzon 16% (n = 6); the Visayas have no value at all. The first Port Barton island-hopping stop had vast monospecific staghorn and tabulate Acropora thickets beside an unbroken pavement of violet-edged foliose plating coral, with massive Porites bommies between them; Abdens at El Nido had broad fields of tabular plates, one several meters across; Sombrero Island in the Verde Island Passage had enormous tabular Acropora plates meters across with columnar Porites. Elsewhere the community is soft. Ligpo Island off Anilao carries dense Dendronephthya, Sarcophyton, and pulsing Xenia fields among barrel sponges, and Beatriz Island is defined by very large barrel sponges, black coral bushes, and gorgonian fans. Three of the 26 sites are wrecks, where low coral cover is expected because the surface is a hull, not reef: the Alberguin wreck reads 20%, the Akitsushima wreck had too few usable photographs for a figure, and no coral cover is estimated for the Taiei Maru wreck.

No site in the set showed a reef-wide bleaching signal, but localized flags recur across both photographed units. At Anilao, patchy bleaching at Dive and Trek (partly bleached Acropora thickets, a bleached mound-shaped colony, a bleached fine-branching colony, and a partly bleached host anemone), a bleached sea fan, a stark-white colony, and a partly bleached host anemone at Ligpo Island, and at least four bleached fine-branching colonies at Monte Carlo; in the Verde Island Passage, a partly bleached table and two massive colonies with stark-white patches at Sombrero Island and a pale, sharply bordered patch of uncertain cause (possibly disease or partial bleaching) on one colony at Kirby's Rock; in Palawan a possibly partially bleached colony at the second Port Barton stop (one frame), scattered white recent-mortality spots on single colonies at Paglugaban Rocks, two white patches of recent mortality at Abdens, several conspicuously pale colonies on the Alberguin wreck, and a Seriatopora photographed and recorded as dying at Nat Nat. Older damage also appears in the set. Reef 1 near Port Barton town is extensive standing dead branching Acropora, algal-colonized and breaking to rubble, with small live recruits growing on the dead branches, and Anderson recorded pollution damage in one frame. In the Visayas logs the pressures are specific rather than photographed: tabular acroporids overturned at Arco Point by a strong typhoon about two months before the February 2013 dives, and a Sipalay fish assemblage that appeared severely overfished despite good coral structure.

The Visayas logs also describe strong coral, without a survey measurement behind it. Talisay at Moalboal had close to continuous, genus-rich coral; the Sambaguita shallows at 3-4 m were near-continuous branching Porites; the Balicasag Sanctuary wall carried abundant coral; and at Marigondon Cave on Mactan the log calls the hard coral cover and diversity striking given how close the site is to Cebu City. Set against that, Wilkinson (2006) reported Philippine reefs in continuing decline as of 2004, under overfishing and destructive fishing, land-based pollution, sediment from coastal development and reclamation, with only 10-20% of Southeast Asia's more than 630 marine protected areas effectively managed. Souter et al. (2021) estimate that hard coral cover across the East Asian Seas dropped to 35% by 2012 after the 2010 mass bleaching and to 33.9% in 2017 after the 2016 event, before recovering to about 37% in 2019.