Annex 2 - Ecological and Socio-Economic Criteria of the Tubbataha Natural Reefs Park Particularly Sensitive Sea Areafootnote
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Statutory Documents - IMO Publications and Documents - Resolutions - Marine Environment Protection Committee - Resolution MEPC.294(71) - Designation of the Tubbataha Reefs Natural Park as a Particularly Sensitive Sea Area - (adopted on 7 July 2017) - Annex 2 - Ecological and Socio-Economic Criteria of the Tubbataha Natural Reefs Park Particularly Sensitive Sea Area1

Annex 2 - Ecological and Socio-Economic Criteria of the Tubbataha Natural Reefs Park Particularly Sensitive Sea Areafootnote

1 Introduction

1.1 The Tubbataha Reefs Natural Park (TRNP) is comprised of the Tubbataha Reef complex, the Jessie Beazley Reef, and their surrounding waters, enclosed within a Core Zone established under Republic Act No.10067. Established and maintained by the Philippine Government since 1988, the TRNP presently encompasses an area comprised of a 97,030 hectare "Core Zone" and a 350,000 hectare "Buffer Zone" surrounding it. It is approximately 80 NM southeast of Puerto Princesa City, the capital of the Philippine island province of Palawan. In 1993, it was inscribed as a World Heritage Site. The TRNP was also inscribed in the Ramsar List of Wetlands of International Importance in 1999. Since 2009 the Park has been designated as a national MPA through Republic Act 10067, which establishes a 10 NM Buffer Zone around the perimeter of the Core Zone of the TRNP, see figure 1 below.

1.2 The Tubbataha Reef complex is comprised of the North and South Atolls. The North Atoll is a large oblong-shaped reef platform 2 km wide and enclosing a sandy lagoon some 24 m deep. The seaward face of the reef is comprised of steep and often perpendicular walls extending to a depth of 40 to 50 m. The South Atoll is a small triangular reef up to approximately 1 NM wide. It also consists of a shallow platform enclosing a sandy lagoon. The North and South Atolls are separated by a 5 NM channel. Each atoll has an islet associated with it: the Bird Islet in the North Atoll and the South Islet in the South Atoll. Bird Islet serves as an internationally significant nesting site for birds and marine turtles. South Islet is a coralline-sand cay of approximately 800 square metres, and is also used as a nesting site. Jessie Beazley Reef is 13 NM north of the two atolls. It extends some 640 m in a north-westerly direction, and is approximately 137 m wide. A small hill of broken coral stands at the centre of the reef about 1.8 m high devoid of vegetation. At low water, the reef bares over a considerable area. A small number of birds will sometimes land on the bare parts of the reef. A white sand cay is readily visible by day from a distance of 3 to 5 NM.

Figure 1 Map highlighting the 10 NM Buffer Zone around the TRNP The Reef Ecosystem in the TRNP

1.3 Atolls like those in the Tubbataha Reef complex are formed when living corals colonize the edges of seamounts or volcanoes. As the volcano gradually sinks underwater, corals reaching for sunlight grow upward toward the sea surface, building on top of thick layers of coral reefs. The Park thus includes extensive reef flats and perpendicular walls reaching over 100 m depth, as well as large areas of deep sea.

1.4 The TRNP's North and South Atolls each have two principal but very different habitats: (1) the outer reef slopes, and (2) the lagoon. The outer reef slopes have very clear water, strong wave action and currents, high oxygen and low nutrient contents, and a very wide depth range from about 1 m to over 40 m. The lagoons have turbid water, little wave action or currents, lower oxygen and higher nutrient content, higher temperatures than surrounding waters, and a much more restricted depth range of from less than 1 to 25 m. The outer reef slopes have much greater coral diversity than the lagoon, and consequently much higher values in terms of biodiversity, biological productivity, and tourism potential.

1.5 The TRNP is universally important because it is one of the world's few remaining examples of a highly diverse near-pristine coral reef. It is located within the Coral Triangle (figure 2), the centre of global coral biological diversity that is also a region of high fishing pressure. The TRNP is an important source of fish, coral, and decapod larvae that enrich fisheries in the greater Sulu Sea area, including the surrounding Philippine islands and their coastal waters. Its huge assemblages of fish and corals attract scuba divers from around the world and provide opportunity for tourism. It is also a living laboratory with an enormous potential to contribute to educational and scientific advancement. These factors make the protection of the TRNP more critical to science and the regional economy.

Figure 2: Map of the Coral Triangle


1.6 As a marine protected area with coral reefs, small islets, and large sea spaces, the TRNP simultaneously evinces multiple criteria for PSSA designation. This part indicates the presence of all these criteria within the Park's boundaries. As a general rule, the ecological, socio-economic, and scientific values apply across the entire TRNP, especially with respect to marine life, habitat, and human uses. Certain values related to its terrestrial components are naturally localized and concentrated, but overall, the pristine conditions of their surrounding waters and the entire Park also ensure sustainability of the environmental conditions that make such localized areas viable. The various criteria for PSSA designation are as acutely intertwined as are the various components of the TRNP ecosystem.

2 Ecological criteria

Uniqueness or rarity

2.1 TRNP is one of the last few remaining examples in the world of a highly diverse, near-pristine coral reef complex in an offshore area located far from human settlements. The great distance from population centres and separation by deep waters from inhabited landmasses have protected TRNP's reefs from degradation and destruction due to over-exploitation associated with many other near-shore reef systems in the Philippines (UNESCO 2008; UNESCO 1992). TRNP is the largest and only atoll reef complex enclosed within the Philippine archipelago. Its high levels of biodiversity and abundant biological productivity are unmatched by any other coral reef in the country (Alino et al. 2002). It stands out as the most intact and diverse of all of the marine reserves in the Philippines (IUCN 2009; UNESCO 1992; Arquiza 1990). It has been referred to as the "crown jewel" of Philippine marine protected areas and biodiversity conservation priorities (UNESCO 2013). It is also the only purely offshore or marine World Heritage Site in Southeast Asia today (Aquino et al. 2011).

Critical habitat

2.2 The entire TRNP is home to significant populations of critical endangered species of marine flora and fauna. It hosts considerable assemblages of marine life equal to, if not surpassing, coral reef sites of the same size around the world. It contains 401 out of 461 species of hard corals (zooxanthellatescieractinians) found in the Philippine waters (TMO 2003). More than 600 species of fish have been compiled from various fish surveys in the TRNP, which include protected species of fish such as the Humphead Wrasse (Cheilinus undulates) (TMO 2015). Endangered species of mollusks like the Topshells (Trachusniloticus), Clams (Tridacna sp.), Tridacnid clams such as crocus clam (Tridacnacrosea), giant clam (T. gigas), scaly clam (T. squamosal), and horse's hoof clam (Hipopushippopus) are found in some parts of the lagoons (Dolorosa 2010; Ledesma et al. 2008; UNESCO 1992). Significant numbers of critically endangered marine turtles are found and have their nesting/breeding grounds in the TRNP. Two species of the highly endangered marine turtles, the Green Sea Turtle (Cheloniamydas) and the Hawksbill Turtle (Eretmachelysimbricata), nest in the islets and use the Park as a developmental stage habitat (Cruz and Torres 2005). Thirteen species of cetaceans (dolphins and whales) and twelve species of sharks have been identified as Park inhabitants. Marine scientists have established that the Sulu Sea is part of the migratory range of the endangered whaleshark (Rhincodontypus) (Eckert et al. 2002). TRNP also supports the highest population densities known to date for white-tip reef sharks (Triaenodonobesus) (Walker & Palomar-Abesamis, 2005). Sightings of white-tip sharks, black-tip sharks (Carcharinusmelanopterus), and eagle rays are common (IUCN 2009).

2.3 TRNP is one of the few diverse strongholds or rookeries of seabirds in the Philippines and Southeast Asia. (Jensen 2009) Its remoteness and protected status make it critical to the continued existence of seabirds in the Philippines. A total of 109 species of birds, both resident and migrant, have been recorded on the islets and cay of the Park. These include species like the brown boobies (Sula leucogaster), red-footed boobies (Sula sula), sooty tern (Onychoprionfuscatus) and crested tern (Thalasseusbergii), as well as the Philippine sub-species of Black Noddy (Anousminutusworcestri), found nowhere else in the world (Aquino et al. 2011). TRNP is the last known major breeding place of the Black Noddy (Anousminutusworcestri). It is also one of only four remaining breeding areas for the Sooty Tern (Fuscatanubilosa), the other three being North Borneo, the Paracel Islands, and Layang-layang Island in Malaysia. It is also the last known breeding area for the Masked Booby (Sula dactylatrapersonata) (Jensen 2009; Heegard and Jensen 1992; Wells 1991). Eight species of seabirds have been observed to have resided and bred in the Tubbataha Reef islets. Most of these seabirds have disappeared from their natural roosts in the Sulu Sea and other parts of the Philippines; they can be found only in the Park (Jensen 2009).


2.4 Coral reefs comprise less than 1% of the Earth's surface and less than 2% of the ocean bottom. Despite this scarcity, they support a quarter of all species found in the ocean (SMNH 2013). Hence, as a general rule, many forms of marine life are directly dependent on the existence of coral reef systems. It may be surmised that such systems would be very important for life in semi-enclosed sea areas like the Sulu Sea. The TRNP plays a fundamental role in the process of reproduction, dispersal and colonization of marine life in the Sulu Sea (Campos et al. 2008). The northeast monsoon encourages the transport of larvae towards the Balabac Strait and the opposite monsoon winds transport larvae towards the southwest, to the Cagayancillo Islands and beyond. Internal wave patterns have been observed moving in a westerly direction, towards the eastern coast of Puerto Princesa City, Palawan, and vice versa to the Cagayan de Sulu area, bringing with it marine larvae that enhances fisheries productivity in these localities (Villanoy et al. 2003). One of the very few coral formations in the middle of the Sulu Sea, TRNP functions as a natural fish aggregating area that attracts, sustains, and disperses various marine organisms that depend on the reef's general overall health for their survival. (Campos et al. 2008) As such it performs a major natural role in support of marine biological productivity and sustainability of fisheries in and around the Sulu Sea. TRNP plays a vital role in the stocking of fisheries in the Sulu Sea and adjacent Philippine waters, thus producing much of the region's wealth of fisheries. Oceanographic studies (Villanoy et al. 2003) and larval dispersal investigations (Campos et al. 2008) demonstrate that ocean currents in the Sulu Sea support the distribution of fish, corals, and decapod larvae to the surrounding islands. The Sulu Sea, of which TRNP is part, is also critical to the emigration of commercially important fish species from reserves like Tubbataha Reef to adjacent areas (DeVantier et al. 2004).

2.5 Aside from the six resident species of seabirds on the islets, TRNP is regularly visited by the Christmas Island Frigate (Fregata Andrewsi), a critically-endangered species of which less than 3000 individuals are believed to exist in the world. This foreign species likewise benefits from the protection of TRNP since the Park forms part of its range (Jensen 2009).

2.6 TRNP is one of the elements of the Tri-national Sea Turtle Network of Protected Areas in the Sulu-Sulawesi Marine Ecoregion (MRF 2008). This MPA contributes the largest no-take area in the Philippines' total marine no-take areas (Weeks et al. 2009).


2.7 TRNP contains excellent examples of pristine and near-pristine reefs with a high density of marine life, a spectacular 100 m perpendicular wall, an almost undisturbed reef crest and reef edge, extensive lagoons with seagrass beds and coral beds, and two coral islands (UNESCO 2015a; UNESCO 1992). The Tubbataha Reefs complex is among the best-documented examples of diverse and concentrated coral atoll systems in Southeast Asia (UNESCO 1994; White 1991). This is among the reasons why TRNP is part of the Palawan Biosphere Reserve, one of two biosphere reserves designated in 1990 under the UNESCO Man and Biosphere Programme (UNESCO 2015b). It is also the largest MPA in the Philippines, and its Core Zone represents 65% of the most highly protected waters of the country (Ong et al. 2002).


2.8 The reef complex contains a diverse coral assemblage, with species representing 80 of the 111 coral genera found worldwide. There are endemic coral species found only in the lagoons, most notable of which are 30 species previously unreported in the Philippines (Fenner 2001). TRNP contains 374 species of corals representing almost 90% of all species in the Philippines and about 80% of all coral species in the Sulu-Sulawesi Seas (UNESCO 2015a; TPAMB 2014). Several distinct physiographic zones are discerned on the reefs. The deep stretches of the steep drop-off show foliose or plate-like forms of Pachyseries, Leptoseris, and Montipora at 20-30 m depth. At 12-20 m depth, massive Diploastrea, Platygyra and Porites are found. The reef edge is an Acropora zone with branching Montipora, Pocillopora, Porites, and some faviids, and extends to a reef slope of similar composition. The reef flats consist mainly of A. hyacinthus, Pocillopora, Millepora, and some faviids. Porites "micro-atolls" and branched Porites characterize the back-reef areas (UNESCO 1992).

2.9 A very high diversity of fish species has been recorded with 600 species in at least 40 families. Among the reasons cited by UNESCO for inscription of TRNP as a World Heritage Site was the exceptional diversity of corals and fish, particularly pelagic fish species such as jacks, tuna, barracuda, and sharks (UNESCO 1992). Forty-five species of benthic macroalgae and four species of microalgae are found, and extensive seagrass beds grow in the shallower parts of the lagoon. The four dominant species are Thalassiahemprichii, Halophiliaovalis, Haloduleuninervis, and H. Pinifolia (UNESCO 1992).


2.10 Fish biomass in TRNP is estimated to be as much as 200 metric tons per square kilometre in the last decade, the highest in the country. It is far higher than the average biomass of healthy reefs elsewhere in the Philippines, which is estimated to be from 35-40 metric tons per square kilometre (TMO 2014). The very high fish biomass estimates in TRNP translates to more larvae that serve to seed degraded fishing grounds surrounding the Sulu Sea. The productivity of TRNP therefore is linked to the productivity of the Sulu Sea and surrounding waters.

Spawning or breeding grounds

2.11 TRNP is a major source and sink of larvae in the Sulu Sea. Larval dispersal simulations show that within a 12-month period, TRNP broadcasts larvae into most of the fishing areas in the Sulu Sea (Campos et al. 2008). As stated above, various threatened or critically endangered species such as marine turtles, seabirds, sharks, and molluscs also spawn or breed within the TRNP.


2.12 Marine life in TRNP thrives on account of its being relatively undisturbed for hundreds of years, due to its remote location and inaccessibility. Weather conditions limit access to the Park, so that tourism activities can be controlled and conducted only three months every year, from mid-March to mid-June. The Park is otherwise left in its natural condition for the rest of the year, and is free from human habitation except for the 8-12 Park Rangers in residence in a centrally located ranger station that stands watch over the MPA. The remote and undisturbed character of the TRNP and the continued presence of large marine fauna such as tiger sharks, cetaceans and marine turtles, large schools of pelagic fish such as barracuda and trevallies add to the ecological and aesthetic qualities of the TRNP (UNESCO 1992). For this reason, The UNESCO designated the TRNP as a World Heritage Site in 1993. It is the first such site in the Philippines, having been approved for inscription for satisfying three of the four criteria for World Heritage Sites. The criteria included the fact that TRNP contained "superlative natural phenomena or areas of exceptional natural beauty and aesthetic importance," "outstanding examples representing significant ongoing ecological and biological processes in the evolution and development of terrestrial, freshwater, coastal and marine ecosystems and communities of plants and animals," and "most important and significant natural habitats for in-situ conservation of biological diversity, including those containing threatened species of outstanding universal value from the point of view of science or conservation" (UNESCO 2008; UNESCO 1992).


2.13 The TRNP comprises the North and South Atolls and the Jessie Beazley Reef. It includes open sea areas with an average depth of 750 m and contains a well-preserved marine ecosystem with top predators, a large number and diversity of coral, as well as pelagic and demersal fish species. It is of sufficient size to maintain associated biological and ecological processes; this also ensures the complete representation of the key features and processes of the reef ecosystems within it. The low level of fishing pressure, due to the no-take policy in place throughout the park, is key to maintaining its integrity. However, maintenance of ecosystem values within the TRNP requires measures to be taken outside the TRNP boundaries, in relation to some migratory species and to create a buffer from threats to the marine environment that could occur in the wider area.

2.14 Compared with other Philippine reefs, the corals of TRNP have recovered well from the bleaching events, the most serious of which took place in 1998 resulting in 21% loss of coral cover. The reefs recovered faster than in locations where human activity was intense. Scientists suspect the protected status of the reefs allows it to better recover from one stress because they do not have to deal with other stresses such as pollution and fishing (Francisco et al. 2008). The corals' resilience is a sign that TRNP has been able to maintain its integrity despite the onset of environmental stressors. Well-connected reef systems usually take 10 to 20 years to fully re-establish after a massive disturbance (Fabricius et al. 2007).


2.15 Coral reefs like those in the TRNP are fragile ecosystems to begin with; they require a delicate balance of environmental conditions to survive and thrive. The existence of a coral ecosystem may be threatened by changes to even one of those environmental conditions. Corals grow very slowly, with the fastest growing species expanding by more than 6 inches (15 cm) per year. Most corals grow less than an inch per year (SMNH 2013). This slow growth contributes to the vulnerability of the reefs to natural and man-made damage or disaster. Thus, even brief changes in water quality (e.g. turbidity, salinity, acidity) could threaten the very survival of coral reefs. For this reason, corals are considered a threatened species. The health of most reefs across the region is in decline as a result of human exploitation (CRA 2014). It has been suggested that one third of reef-building coral species are under elevated threat of extinction due to human impacts and climate change (Carpenter et al. 2008). Shipping activities may generate low-level but constant impacts that accumulate over time, such as operational pollution, as well as introduce risks of occasional or accidental impacts such as large oil or chemical spills that may be relatively brief but potentially catastrophic.

2.16 Climate change impacts increase the vulnerability of coral reefs to degradation. It negatively affects sea surface temperatures, which are suspected to be the cause of "coral bleaching" where live coral in the sea die prematurely, leaving white coral reef skeletons. Extreme environmental conditions such as warmer-than-usual waters, combined with man-made accidental pollution events, could push coral reefs beyond the limits of their biological resilience and result in their destruction in a short period of time. As demonstrated by the coral bleaching event in 1998 resulting in 21% loss of coral cover, TRNP is already close to the limits of its ability to recover from natural stresses. Coincidence with human-induced stresses arising from shipping activities is thus a major risk at present.

Bio-geographic importance

2.17 TRNP is located at the apex of the Coral Triangle, the richest biogeographic region in the world, home to the highest concentration of marine species on the planet. The Coral Triangle, often called "the Amazon of the Seas", is home to 600 corals or 76% of the world's known coral species. It contains the highest reef fish diversity with 2,500 or 37% of the world's reef fish (CTI 2015). As a result, TRNP is considered to be "extremely high" on the list of marine conservation priority areas of the final report of the Philippine Biodiversity Conservation Priorities Project implemented by the government with foreign development assistance to support the long-term planning and rationalization of Philippine environmental conservation efforts. It is also ranked as "very high" on the list of conservation priority areas for birds, reef fishes, corals, molluscs, seagrass, elasmobranches, and turtles (Ong et al. 2002). The convergence of the ranges of multiple terrestrial, marine, and aerial species (as noted above) within the Park make it an ideal and strategic location for environmental conservation and protection, with expected associated impacts extending not only to other areas of the Philippine archipelago but to the rest of the Southeast Asian region as well.

3 Social, cultural and economic criteria

Social or economic dependency

3.1 The TRNP makes direct contributions to the national and local economy through tourism revenues generated from scuba divers, and has been ranked as the eighth best diving destination worldwide (CNN 2012). Indirect contributions are derived to the fisheries by functioning as a habitat and source of larvae. The total economic value of TRNP based on tourism revenues and larvae contributions for fisheries is estimated at over $6 million annually, while values derived from non-use or simply serving as a protected habitat has been estimated at $2.5 to 4.8 million (Subade 2007).

Human dependency

3.2 The TRNP is a key source of coral and fish larvae, seeding the greater Sulu Sea. It has a decisive role in sustaining the fisheries in surrounding areas, directly providing food and livelihood for hundreds of thousands of Filipinos (Campos et al. 2008). The Philippines has nearly 2 million people who are dependent on fisheries for their livelihood (BFAR 2012). This relatively small ecological contribution translates into more substantial benefits for the human population. The TRNP is a source of fish larvae whose benefits extend beyond its borders, and is the source of municipal/artisanal fishers and commercial fishers in areas outside the Park (Campos et al. 2008). Larvae dispersal to the surrounding area is estimated to be worth almost $3 million (Subade 2007). The inhabitants of the isolated island Municipality of Cagayancillo are directly dependent on fishing in their municipal waters, which are in turn dependent on the productivity of the TRNP. Cagayanon fishermen once reported that fish catch in their waters doubled in the three years since the establishment of the no-take policy of the TRNP, indicating that management of the fisheries in the Park area benefits neighbouring areas as well (UNESCO 2008; Cola 2008).

3.3 On a larger scale, strong wind variations from the Mindoro Strait, Balabac Strait, and Sulu archipelago create upwelling and downwelling events that affect primary productivity and the concentration or distribution of fish and other marine life. The predominantly westward movement of ocean currents in the Sulu Sea transport fish eggs and larvae to the eastern coast of Palawan; this ensures the sustainability of fisheries in mainland Palawan (Villanoy et al. 2003).

Cultural heritage

3.4 On account of its remoteness and extremely limited land area, the Park does not contain significant historical and/or archaeological sites. The few shipwreck sites located within the Park boundaries to date serve only as dive sites, and have not been the subject of marine historical or archaeological studies.

4 Scientific and education criteria


4.1 Scientists, especially biologists, oceanographers and geologists have been fascinated by the manner of reef formation in the Sulu Sea and by its high biodiversity in terms of species numbers and habitat types. They consider these reefs to be prime research and experimental sites because they are associated either with emergent islands or islets, or with submerged structures. The TRNP's unique position in the middle of the sea and interactions between the atolls and surrounding marine ecosystem make it an ideal laboratory for the study of ecological and biological processes, in particular larval dissemination and fish recruitment. The TRNP offers marine researchers an opportunity to discover and study the biology and ecology of marine ecosystems at various spatial scales. Subjects for study could vary from minute plankton to the large marine mammals and apex species (TMO 2015). Scientific interest in the Tubbataha Reef complex has been increasing. During the 1980s, only five commissioned studies were conducted in the area, starting in 1982. In the following decade there were ten. Between 2000 and 2006, the number of studies had increased to 25 (Conservation International, 2006). At present, 31 studies are available online directly from the Tubbataha Management Office (TMO 2015b); these do not include many others published in scientific journals and in print.

Baseline for monitoring studies

4.2 Corals support numerous reef inhabitants and are thereby considered to be a key measure of reef habitat quality and quantity (Bruno and Selig 2007). Being separated from land by deep water, TRNP is relatively free from land-based sources of pollution and as such forms a unique area for scientific study and comparison with other areas in the Coral Triangle.


4.3 TRNP is a living laboratory for the study of marine ecological processes and climate change adaptation. As part of the Palawan Biosphere Reserve of the UNESCO Man and Biosphere Programme, TRNP is considered a "Science for Sustainability support site," or a special place for testing interdisciplinary approaches to understanding and managing changes and interactions between social and ecological systems. Each reserve promotes solutions to reconcile biodiversity conservation with sustainable use (UNESCO 2015b).

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