Apo Coral Reef

• Category: Marine and Oceanic Biomes.
• Geographic Location: Asia.
• Summary: The Apo Coral Reef is an atoll-like platform reef considered to be the second-largest contiguous coral reef in the world and the largest in the Philippines.

The Apo Reef is situated approximately 15 nautical miles (28 kilometers) west of Mindoro, the seventh-largest island in the Philippines. The reef forms the core of the Apo Reef Natural Park, which is comprised of a series of islands, coral reefs, and adjacent waters, all of which aid in conserving a vast diversity of regionally and internationally important species. The park encompasses approximately 61 square miles (158 square kilometers), surrounded by an additional 45-square-mile (117-square-kilometer) buffer zone. Apo Coral Reef itself consists of a series of coral reefs within the park, covering approximately 13 square miles (34 square kilometers).

Apo Reef, the primary geographic feature of Apo Island, is the largest atoll-like reef in the Philippines. Its two platform reefs encompass approximately 34 square miles (88 square kilometers). Apo Reef is located at the northern tip of the Coral Triangle, an area of 2.2 million square miles (5.7 million square kilometers) that contains the seas of six countries, including the Philippines, Indonesia, Malaysia, Papua New Guinea, the Solomon Islands, and Timor-Leste. It has been estimated that approximately 25 percent of the world's islands lie within the triangle and that this area harbors at least 500 species of reef-building corals.

The Apo Reef Natural Park includes Apo Island as well as Apo Menor (Binangaan) and Cayos del Bajo (Tinangkapaang). Apo Island, the largest of the islands in the reef conglomeration at 54 acres (22 hectares), contains a shallow lagoon 6.6 to 32.8 feet (2 to 10 meters) deep, a mangrove forest, and beach vegetation. By contrast, Binangaan is a rocky limestone island and Tinangkapaang is mainly coralline rock; neither of these two has much vegetation.

Apo Island provides a variety of habitat types and ecosystems, accounting for the high density and diversity of species. The lagoon is an important source of food, and is a nursery and spawning ground for a variety of coastal and marine species. The mangroves serve as a vital nursery area for juvenile fish and play an important role in nutrient production that contributes to the aquatic food chain. The mangroves in combination with the lagoon are home to several species of fish, stingrays, jellyfish, marine plants, and other organisms. Sandy beaches, beach forest, and karstic rock habitats (geological formations created by the dissolution of soluble bedrock) serve as transitional zones between marine and terrestrial habitats. The beaches serve as nesting habitats for the green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) sea turtles. Also dependent on these transitional habitats are a variety of crustaceans, mollusks, and polychaetes.

Aside from the coral reefs, the marine habitat includes extensive seagrass and macroalgae beds on or adjacent to the reef proper; this zone is home to diverse corals, fish, marine plants, and other marine organisms. The marine biodiversity is impressive, with surveys estimating as many as 385 species of fish, 400 different coral species, 26 algae species, and seven species of seagrass. Seabirds are also well represented, with as many as 46 migratory and resident species roosting regularly on Apo's three islands.

Environmental Stresses

Due in part to the vast diversity of marine organisms, Apo Reef was viewed as one of the world's premiere diving destinations 30 or 40 years ago. In the 1970s, however, destructive fishing practices such as dynamite, cyanide, muro-ami (a local net-and-crush technique), and strobe-fishing were implemented on Apo Reef, all which had devastating effects on the marine environment. People from as far away as Cebu, Navotas, and other distant Philippines cities came to fish at Apo Reef to reap the rewards. These negative effects became so pronounced that in the 1980s, the international diving community lost interest in the area. A survey conducted in 1994 concluded that the remaining coral covered only 33 percent of the entire reef.

To add insult to injury, an El Niño event in 1998 raised ocean temperatures in the area, which produced a massive coral-bleaching event and killed countless corals. Additionally, the reef is subject to the same threat as low-lying islets and lands around the world: the sea-level rise attributed to man-made global warming, and the attendant higher intensity of storms and cyclones.

Alternative modes of fishing are slowly being developed and implemented in the area. The use of fish aggregation devices (FADs) in the area, for example, has demonstrated that a single FAD can yield a minimum of 33 pounds (15 kilograms) of fish daily. The FAD technique is a passive way to attract fish that voids the use of destructive nets, draglines, and other previously very prevalent methods. Some locals are resistant to change, but in the long term, both the fishers and the marine environment will benefit.

Conservation Efforts

Updated surveys conducted in 2003 and 2006 concluded that coral coverage had increased to 43 percent and 52 percent, respectively. In addition to the 19-percentage-point increase in coral coverage in a period of 13 years, larger fish have begun to return. Schools of hammerhead sharks, manta and eagle rays, whale sharks, and sperm whales are being sighted regularly, which is a sign that Apo Reef's biodiversity is rebounding. As the reefs recover and the fish stocks increase, it is hoped that the outlying waters will be seeded sufficiently for sustainability.

Apo Reef lies in waters that are under the jurisdiction of the province of Occidental Mindoro in region IV-B of the Philippines; it is administered by the local government of the municipality of Sablayan. The reef was originally declared a marine park by the Philippines president in 1980. Three years later, the local government of Sablayan declared the reef a special Tourism Zone and Marine Reserve. On September 6, 1996, the entire reef was proclaimed a Protected Area under the category of Natural Park, and its surrounding waters were made a buffer zone by virtue of Presidential Proclamation No. 868. In 2006, the Protected Areas and Wildlife Bureau of the Philippine Department of Environment and Natural Resources submitted Apo Reef to the United Nations Educational, Scientific and Cultural Organization (UNESCO) for consideration as a World Heritage Site; it is currently designated on the UNESCO “tentative” list.

In 2007, fishing, collection, and harvesting of any life form within the park was banned by the Philippines government. The entire park was declared a “no take” zone to allow the reef time to recover from decades of overfishing. Instead, the park was accessible mainly to scientists and to tourists, who in return will assist in generating funds for the protection of the reef, as well as providing an alternative livelihood for area fishers. The conservation efforts proved successful. In 2022, Apo Reef National Park won the Blue Park Award for marine wildlife conservation at the United Nations' Ocean Conference.

Bibliography

"Apo Reef National Park Bags Int'l Marine Conservation Award." Inquirer.net, 7 July 2022, newsinfo.inquirer.net/1623457/apo-reef-natural-park-bags-intl-marine-conservation-award. Accessed 14 Oct. 2024.

“Apo Reef Natural Park.” UNESCO World Heritage Centre Global Strategy, 2012, . Accessed 14 Oct. 2024.

Jennings, Simon, et al. Marine Fisheries Ecology. Wiley-Blackwell, 2001.

Sheppard, Charles R. C., et al. The Biology of Coral Reefs. Oxford UP, 2009.