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
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).
Dependency
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).
Representativeness
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).
Diversity
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).
Productivity
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.
Naturalness
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).
Integrity
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).
Fragility
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.