Coral Reef Diagnostics

Philippines

NOAA Coral Reef Watch

Overview of 26 dive sites. Figures are averages across the sites that report them (n = sites with a value); each site's own page has its individual values. Regional summaries: Luzon, Palawan, Visayas.

⬇ Download this overview as a report card
05
Photo: Anderson Mayfield/Coral Reef Diagnostics — Philippines - Port Barton, Palawan: island-hopping stop 1 (San Miguel area)
Country
Philippines
Sites
26
each linked below
Hard coral cover (overview mean)
27% ± 8.0% (std. dev.)
n = 18 of 26 sites. range 15–43%
Water temp. during surveys (overview mean)
27.8°C
n = 13 of 26 sites; surveyed Sep 2016–Jan 2017
Coral Health Index (overview mean)
not yet scored
n = 0 of 26 sites
Most recent water temperature record
16 Sep 2026 · Central Philippines
Most recent heat stress record
16 Sep 2026 · below alert level
Mean annual max degree heating weeks (DHW), last 5 years
2021–2025 · regional mean of 26 sites, 3 stations
Highest annual heat stress
in 2020 · Central Philippines
Severe heat-stress years
1985–2025 · 6 in the last 10 years
Heat-stress figures: NOAA Coral Reef Watch — Central Philippines and Eastern Philippines, Western Philippines 5-km virtual stations. Each pill links its source record and carries the values behind it.

Heat stress, 1985–2025

04812161985: 0.9°C-weeks (below the bleaching alert threshold)19851986: 2.5°C-weeks (below the bleaching alert threshold)1987: 2.8°C-weeks (below the bleaching alert threshold)1988: 2.4°C-weeks (below the bleaching alert threshold)1989: 0.5°C-weeks (below the bleaching alert threshold)1990: 0.7°C-weeks (below the bleaching alert threshold)19901991: 0.3°C-weeks (below the bleaching alert threshold)1992: 3.7°C-weeks (below the bleaching alert threshold)1993: 0.8°C-weeks (below the bleaching alert threshold)1994: 2.6°C-weeks (below the bleaching alert threshold)1995: 0.6°C-weeks (below the bleaching alert threshold)19951996: 2.3°C-weeks (below the bleaching alert threshold)1997: 0.0°C-weeks (below the bleaching alert threshold)1998: 9.8°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely)1999: 0.6°C-weeks (below the bleaching alert threshold)2000: 0.3°C-weeks (below the bleaching alert threshold)20002001: 2.9°C-weeks (below the bleaching alert threshold)2002: 0.5°C-weeks (below the bleaching alert threshold)2003: 0.2°C-weeks (below the bleaching alert threshold)2004: 0.3°C-weeks (below the bleaching alert threshold)2005: 3.3°C-weeks (below the bleaching alert threshold)20052006: 2.4°C-weeks (below the bleaching alert threshold)2007: 10.4°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely)2008: 0.3°C-weeks (below the bleaching alert threshold)2009: 0.5°C-weeks (below the bleaching alert threshold)2010: 10.9°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely)20102011: 0.2°C-weeks (below the bleaching alert threshold)2012: 4.7°C-weeks (Alert Level 1: significant bleaching likely)2013: 6.3°C-weeks (Alert Level 1: significant bleaching likely)2014: 9.7°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely)2015: 8.0°C-weeks (Alert Level 1: significant bleaching likely)20152016: 11.8°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely)2017: 11.7°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely)2018: 3.3°C-weeks (below the bleaching alert threshold)2019: 10.9°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely)2020: 15.1°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely)20202021: 5.9°C-weeks (Alert Level 1: significant bleaching likely)2022: 8.4°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely)2023: 6.2°C-weeks (Alert Level 1: significant bleaching likely)2024: 14.5°C-weeks (Alert Level 2+: severe bleaching and significant mortality likely)2025: 6.8°C-weeks (Alert Level 1: significant bleaching likely)20254: bleaching likely8: severe bleaching and mortality likely°C-weeks
under 22–33–55–88–10over 10 (🔥 above 12)
Annual maximum Degree Heating Weeks, NOAA Coral Reef Watch 5-km virtual stations: Central Philippines, Eastern Philippines, Western Philippines (highest station each year). DHW ≥ 4: bleaching likely; ≥ 8: severe bleaching and mortality likely. Download the annual DHW data (CSV): eastern-philippines, palawan-north-borneo.

26 sites in this region — click a marker to open that site.

Overview

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 gathers 26 pins in three units, from three separate trips. The Visayas unit holds seven pins 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 Akikushima wreck at Coron. The record is unevenly built: the Visayas pins rest on Anderson's dive logs alone, because every surviving frame from that trip is topside, while the Luzon and Palawan pins have photographs and photo-derived cover.

Photo-derived cover exists for 18 of the 26 pins and averaged 27.0%, from 14.7% on the Taiei Maru oil tanker wreck at Coron to 43.4% at the second Port Barton island-hopping stop. Palawan read slightly higher (28.0%, n = 12) than Luzon (24.9%, n = 6), and the Visayas have no value at all. Acropora and plating corals define the best reefs. 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 pins are wrecks, where the cover figure indexes hull colonization rather than reef.

No site in the set showed a reef-wide bleaching signal, but localized flags recur across both photographed units. At Anilao a stand of stark-white branching Acropora at Dive and Trek, a stark-white colony and a partly bleached host anemone at Ligpo Island, and a partially bleached colony at Monte Carlo; in Palawan a partially bleached colony at the second Port Barton stop, scattered white patches or recent-mortality spots at Paglugaban Rocks and Coral Gardens, a small white patch at Abdens, several conspicuously pale colonies on the Alberguin wreck, and a Seriatopora photographed and labeled dying at Nat Nat. The clearest damage in the set is older. 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 one frame captioned 'pollution damaged reef'. 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 are also where the strongest coral in the set is described, without a number attached to any of it. Talisay at Moalboal was the dive Anderson rated best of the trip for coral, close to continuous and genus-rich; the Sambaguita shallows at 3-4 m were near-continuous branching Porites; the Balicasag Sanctuary wall carried the most coral he had then seen on one dive; 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 36.8% in 2019.

Highlights

Notable observations (12)

Coral cover over time (pooled)

One point per year: the mean of every hard coral cover value available for this region that year — Anderson’s own dives and every independent survey station within 5 km of them. The vertical bar is the full range behind that mean. Different programs use different methods at different stations, so this is a regional summary, not a single comparable series. Three values above 70% were excluded as best-patch figures rather than site means. Years resting on fewer than three values are drawn as smaller points (1999, 2000, 2001, 2018, 2019, 2023). Non-CRD points are from Reef Check Foundation. Marker shape: his own dives, other organizations’ surveys, a mix of both, that year.
0%20%40%60%80%1998 bleaching1998201020231998: mean 37% of 4 values (range 24–61%)1999: mean 43% of 1 value2000: mean 35% of 1 value2001: mean 20% of 2 values (range 12–27%)2002: mean 29% of 7 values (range 17–42%)2003: mean 28% of 15 values (range 7.5–50%)2004: mean 24% of 13 values (range 5.6–46%)2005: mean 22% of 11 values (range 11–44%)2006: mean 17% of 19 values (range 2.8–56%)2007: mean 24% of 16 values (range 4.4–51%)2010: mean 49% of 7 values (range 20–70%)2011: mean 53% of 3 values (range 34–63%)2012: mean 50% of 4 values (range 32–56%)2013: mean 42% of 16 values (range 4.4–69%)2014: mean 45% of 19 values (range 7.5–70%)2015: mean 28% of 5 values (range 24–34%)2016: mean 28% of 7 values (range 19–50%)2017: mean 29% of 22 values (range 11–56%)2018: mean 22% of 1 value2019: mean 24% of 2 values (range 16–33%)2023: mean 14% of 1 value
Sites in this region (26)

Nearby external survey stations

149 independent survey records within 5 km of a site in this region (deduplicated across sites).

Show all 149 records

All images from Coral Reef Diagnostics. Data are from Coral Reef Diagnostics and Reef Check Foundation.

© Coral Reef Diagnostics.