TUBBATHA REEF

What is Tubbataha?

Tubbataha is a reef ecosystem made up of two atolls located in the middle of the Sulu Sea. It is a sanctuary for marine life. The reefs lie on the Cagayan Ridge, a line of extinct underwater volcanoes which starts from the north at the Sultana Shoal and ends in the south at the San Miguel Islands. It is located 92 nautical miles southeast of Puerto Princesa City, Palawan and 80 nautical miles southwest of Cagayancillo, the municipality that exercises political jurisdiction over it. It was proclaimed as a National Marine Park on August 11, 1988 and inscribed as a UNESCO World Heritage in 1993, in recognition of its outstanding universal value in terms of marine life species diversity and richness.

The name Tubbataha comes from the dialect of the Samal, seafaring people of the Sulu region, and means ‘long reef exposed at low tide’. Tubbataha consists of two atolls made up of roughly 10,000 hectares of corals and many other forms of marine life. There is very little land in Tubbataha. Each atoll has just one islet, the highest of which is only two metres above sea level. The atolls have shallow lagoons and are surrounded by 200 to 500 metres of reef flat which ends in a steep drop off into deep water. The reef crests, which mark the atolls’ edges, are exposed above the water’s surface at low tide.

Tubbataha is well known among the fisher folk of the southern Philippines. It was called ‘Gusong’ by the islanders of Cagayancillo, literally meaning ‘coral reef.’  Until the late 1970s, Cagayanons were the primary users of Tubbataha’s resources. During the summer months, they would make month-long fishing trips in fleets of locally built wooden sailboats called pangko or balangay.

For most of its existence, Tubbataha’s remoteness has been its greatest protector against over exploitation. It is open to the shifting winds that affect the Philippines – the habagat, amihan and daplak which bring rough seas, fierce storms and brief periods of calm. The safest months for travel to Tubbataha are during the summer months, from March to May.

The first recorded visit to Tubbataha was made by naturalist Dean Worcester in 1911. He described the north islet – called Bird Island because of its role as a nesting ground for thousands of seabirds – as ‘a low, flat, sandy island…some 400 metres long and 75 metres wide.’ Seventy years later, when ornithologist Robert Kennedy visited the island, he noted that it had shrunk in size by almost 70 per cent. Today Bird Island is a mere 23 per cent of the area recorded in 1911, just one indicator of how dynamic the forces of nature are at Tubbataha.

A vast wealth of marine life  

The Philippines lies within the ‘coral triangle’ – the area with the highest marine biodiversity on earth. Tubbataha is regarded as one of the richest ecosystems on the planet. The diversity of marine life found in Tubbataha is equal to or greater than any such reef of its size in the world.

Researchers have recorded 396 species of corals – 85 per cent of all hard coral species in the entire Philippines. There are 479 species of fish from 46 families. Manta rays are frequent visitors to the reef as are barracudas and large schools of jacks. Tubbataha is also home to six species of sharks – usually found cruising around the outskirts of the reef. There are two types of sea turtles and nine species of marine mammals found in these reefs.

Tubbataha is a big ecosystem containing a network of smaller ecosystems. From the largest fish (the whale shark) down to the tiniest organisms (marine plankton) the underwater flora and fauna depend on one another for survival. The islets are also part of this complex, life-giving network. Sea turtles are often seen around the shallow reef flats. During breeding, they lay their eggs on both the North and South Islets.  The islets also serve as an important refuge for seabirds in Southeast Asia. Tubbataha’s islets is believed to be one of the last breeding grounds for a host of endangered bird species.

Coral reefs are one of the earth’s most ancient ecosystems. They date back to the Mesozoic period around 225 million years ago. Although they cover only 0.2 per cent of the ocean floor, they may produce up to 25 per cent of the fish catch of developing countries and 10 per cent of the total amount caught globally for human consumption. Tubbataha is one of the Philippines’ oldest ecosystems. Scientists have suggested that the reefs’ formation began around 15 million years ago with the eruption of the chain of volcanoes along the Cagayan Ridge.

Tubbataha reefs contribute immensely to the productivity of the fisheries sector. It is thought that the prevailing westward currents take fish and the larvae of other marine creatures towards the east coast of mainland Palawan, one of the country’s richest fishing grounds.

Tubbataha - vital yet endangered  

Coral reefs are under threat. They are among the most endangered ecosystems on earth. Human impacts have already caused the death of 5-10 per cent of the world’s reefs. If this pace of destruction continues, another 60 per cent could be lost in the next 20 to 40 years.

There are around 27,000 km² of coral reef in Philippine waters. They play a critical role in fisheries production, providing livelihood to millions of Filipinos. Marine products supply 50-60 per cent of the country’s protein intake.

However, Philippine coral reefs are currently under great stress. Many have been damaged by destructive fishing methods such as the use of dynamite or cyanide. The latest research shows that roughly 95 per cent of Philippine reefs are no longer in pristine condition and that humans are the prime instigators of this destruction.

Tubbataha has been exploited for decades prior to its declaration as a protected area. While its remote location and inaccessibility has served as a natural barrier, it became more and more vulnerable to large scale fishing in the 1980’s, especially following a decline of fisheries around Cagayancillo and the increased use of motorized outrigger boats. Increasingly, the reefs were fished by larger vessels, some coming from as far as China and Taiwan. In many cases, such fishers pillaged the area taking with them not only fish but turtles, turtle eggs and bird eggs.

According to the Cagayanons, in was in the late 1980s when large numbers of fishermen, predominantly Visayan, introduced the practice of cyanide and dynamite fishing in Tubbataha. Soon enough, some local fishermen learned the technique and began using them too.

These fishing methods were very destructive and caused long-term damage to the reef. Using air compressors for breathing, fishermen dive into the corals and squirt a cyanide-based solution to stun the fish for easy capture. It is widely practiced as a technique in catching live fish which brings higher yield to the fisher. In the process, the corals are poisoned to death.  Blast or dynamite fishing involves the detonation of small home-made bombs and dynamites in shallow reef areas. The damage caused by this practice is immense, as fish larvae, young fish and corals are killed in the process. Even the fishermen themselves are exposed to danger from the explosives.

Since the early 1980s, Tubbataha has been one of the most popular scuba diving destinations in the Philippines. It is known for its vibrant and pristine coral reefs. It was inaccessible to many because of its isolated location. But by the end of the decade, more and more poachers came to fish. Destructive fishing had taken its toll on the reef and the area could no longer be described as pristine. In 1989, research showed that living corals on the outer reef flats had decreased by 24 per cent in just five years. During their regular visits to the reef, scuba divers saw what was happening to Tubbataha and began to worry about its destruction. Ernesto ‘Bebot’ Santa Cruz, who was then working for the Philippines’ Task Force Pawikan, proposed to safeguard Tubbataha by having it declared a protected area. The Provincial Council, which was chaired by Vice Governor Arthur Ventura, then asked the President to establish Tubbataha as a National Park. Finally on August 11, 1988 when President Corazon Aquino signed Presidential Proclamation 306 which made Tubbataha the county’s first national marine park.

Tubbataha’s troubles did not end in 1988 when it was declared into a park. A company engaged in seaweed production and export had begun to set up a plantation right on top of Tubbataha’s reef flats. The plan was to bring in some 6,000 workers to live on the remote islets and cultivate seaweeds. The operation was effectively stopped by vigilant conservationists. However, the removal of the demonstration seaweed farm from Tubbataha took over a year of concerted efforts.

December 11, 1993 was a milestone for Tubbataha. It was inscribed by UNESCO as a World Heritage Site – the only purely marine World Heritage Site in Southeast Asia.  There are only nine entirely marine World Heritage Sites in the world and this international recognition of Tubbataha’s global significance was an important step in generating support to safeguard the reef.

Even after Tubbataha was declared a national marine park, authorities have been battling to protect it from illegal exploitation. Today, rangers from the Philippine Navy, Philippine Coast Guard and Tubbataha Management Office are permanently stationed in Tubbataha all year. They conduct regular patrols around the park perimeter to stop illegal fishers from entering.

Tubbataha and climate change

Coral reefs around the world are under serious threat due to man’s unabated emission of greenhouse gases into the earth’s atmosphere. The resulting increase in the temperature of the oceans has dire consequences. Scientists expect tropical sea surface temperatures to increase by 1-3°C over the next century and this could be catastrophic for coral reefs. Rising temperatures cause coral ‘bleaching’ which, if prolonged, causes slower rates of growth and reproduction and can eventually lead to the death of entire colonies. According to experts, Tubbataha is particularly vulnerable to water temperature increase due to its position in the middle of the Sulu Sea which is open to the flow of hot water from the north, through the Mindoro Strait, and from the south, through the Balabac Strait. The clear waters of Tubbataha make this even more of a threat as high light intensity contributes to the bleaching process.

The worst bleaching event ever recorded took place in 1998. In some parts of the world, live corals were completely lost. In late June to early November that year, coral bleaching took place all over the Philippines. Around 20-50 per cent of all reefs were seriously affected. Some recovered while others did not. Research carried out by the World Wildlife Fund (WWF) and The University of the Philippines  - Marine Science Institute (UP-MSI) showed that although affected, Tubbataha has been able to recover from the 1998 bleaching event.

Management strategies

The “no take” policy in effect in Tubbataha has demonstrated the effectiveness of marine protected areas (MPA) in providing refuge to fish, corals and other forms of marine life. It had allowed the reefs to recover easily from the 1998 bleaching event. MPAs are essentially sanctuaries for fish, corals and other forms of marine life. ‘No-take’ zones are areas wherein the collection any form of marine life is prohibited. In this way, they protect breeding grounds and provide fish with a refuge. The effective management of MPAs protects its spawning stock population and guarantees stock supply to other areas via fish migration and the dispersal of larvae.

Only activities related to tourism, research and conservation are allowed in the Tubbataha Reef National Marine Park (TRNMP). It is a ‘no-take’ zone where catching or collecting anything is strictly prohibited. Tourists and dive operators are oriented to the regulations within the park in order to minimize the impact the negative impact of diving activities. The absence of major human disturbances in Tubbataha allows the reef to heal naturally.

The park is managed by the Tubbataha Protected Area Management Board (TPAMB). Of the 439 MPAs in the Philippines, it is one of the few that has a functional organisational structure and an operational management plan. The board, established in 1999, is made up of a wide range of stakeholders. Past experience has shown that the conservation of Tubbataha is too big and complex a task to be entrusted to one organisation alone. The TPAMB is therefore represented by many different groups who are concerned with the conservation of Tubbataha Reefs. They remain vigilant to the changing times and are attuned to new challenges. They seek to involve new stakeholders and partners in the decision-making process. Through this, they have created an expanding network of interrelated groups and individuals whose focus is to safeguard the future of Tubbataha for the benefit of all.

         
Scientific research

In 1982, a combined team from the Government and the University of the Philippines Marine Science Institute carried out one of the first scientific surveys of Tubbataha.

Still, it was not until 1997 that the monitoring of the reef was standardized. Since that time, scientific surveys of Tubbataha have been a regular annual activity. Based on information gathered from these surveys, The World Wildlife Fund (WWF - Philippines) described Tubbataha as ‘probably the most important marine protected area in the Sulu Sea.

Every year since 1997, research teams have been sent to Tubbataha to gather data on the health of the reef. Through these visits they provide much of the information needed to carry out the TRNMP Management Plan. The research team makes observations on corals, fishes, seagrasses, seabirds, marine plankton, and marine mammals, such as dolphins and whales.  In recent years, Tubbataha has been visited by scientists from other groups such as Conservation International (2004) and the WWF Climate Change and Energy Unit (2004-2005). Research trips normally take place during summer when the weather allows for the safe passage of the research vessel and good scuba diving conditions so that the team can safely and effectively carry out their work. A few weeks of calm in September or October during the monsoon break also provides a brief opportunity for research.

In 2001, the Tubbataha research and monitoring team to visited other sites along the Cagayan Ridge - Jessie Beazley Reef to the northwest of Tubbataha, and some sites around Cagayancillo Island. In 2002, they branched out even further to include Basterra Reef, to the south of Tubbataha, and reefs around the islands of Arena, Cawili and Calusa, close to Cagayancillo.   These surveys allowed marine biologists to compare data from areas which were open to different levels of exploitation. They were able to compare the condition of coral reefs inside and outside a protected area, looked at sites which were fished to different extents and using different methods. This gathered data highlights the forces shaping the coral reef communities in these areas, forces which in turn will affect a diverse range of marine and terrestrial life.

The results of the research carried out since 1997 show that the condition of the fishes and corals of Tubbataha and other sites, such as Jessie Beazley and Cagayancillo, is improving. Cagayanon fishermen have reported that fish catch in their waters has almost doubled in the past three years alone. This indicates that ‘no-take’ zones may allow fish populations to increase not only inside the marine protected area itself but in neighbouring areas as well.

         
Coral research

The latest research suggests that the 1998 bleaching event had a minimal effect on the corals of Tubbataha. Since 1998, the reefs have shown gradual recovery and improvement. From 1997 to 1999, roughly 16 per cent of hard coral cover was lost. However, hard corals now cover around 46 per cent of the reef - almost the same as in 1997, before the bleaching.  At the same time, soft corals have increased in coverage. Algae, which increased after the bleaching, has declined. Compared to other Philippine reefs which experienced a coral mortality rate of 50 to 90 per cent, Tubbataha showed resiliency from the bleaching event.Scientists have suggested that protection efforts in Tubbataha contributed to this. The corals were protected from human disturbances, allowing the reef to recovery. Scientists have observed Tubbataha’s corals as being in ‘good condition’.

In 2003, Basterra Reef was classified as being in ‘poor condition’. According to the latest research, its condition is ‘fair’. Scientists have pointed out that Basterra, which is not a protected area, may be suffering from over-exploitation. Like Tubbataha, Basterra is an offshore reef and used to face little fishing pressure due to its remoteness. Now, however, the reef’s isolation no longer saves it from disturbance since poor fish catch in more accessible areas has driven fishermen to Basterra. In fact, the reef’s isolation may be attractive to fishers who may target it due to its high potential for exploitation. Illegal and destructive fishing activities have been reported in Basterra. It was observed that many fishers are resorting to these techniques in order to maximize their catch in a short period of time. Research conducted on other offshore reefs has shown that in such cases corals are left devastated. This points to two things – the need to protect Basterra from over-exploitation and the continued need to guard Tubbataha from such threats. The research findings indicate that in the absence of vigilance, Tubbataha would again be victim to illegal and destructive fishers.

The comparison between Cagayancillo reefs and its neighbouring island Cawili tells a similar conclusion. Scientists describe Cagayancillo as ‘fair’ while Cawili is said to be in ‘good condition’. According to researchers, this can be ascribed mainly to the attitudes of the different island communities towards their reefs. Although reef destruction in Cagayancillo is largely attributed to pressure from transient fishers, the island’s corals have also suffered significantly from the local community’s lack of awareness. On the other hand, ecological awareness of the residents of Cawili is high and people are remarkably proud of their natural resources. This research indicates that the condition of a reef is closely related to each community’s awareness and concern for their natural resources. The population of Cawili sets a good example of how communities can benefit from the coral reefs without destroying them.

Fish research

Since 2001, scientists have been surveying areas along the Cagayan Ridge which are open to varying degrees of fishing intensity – from Tubbataha’s ‘no-take’ zone to heavily fished areas such as Cagayancillo and Basterra. They compare data from different sites in order to analyse the health of different reefs and to assess the effectiveness of MPAs. One way in which this is done is to estimate the total fish biomass - the total mass of living fish - in specific areas. This estimation is calculated in metric tonnes per square kilometre (mt/km²).

The total fish biomass for Tubbataha in 2005 was estimated at 318 mt/km². This is remarkable when one considers that just 5 to 37 mt/km² is expected from a healthy coral reef. The ‘no-take’ policy tends to be justified by the research results. In 2004, the highest fish biomass along the whole Cagayan Ridge was found within the MPA. During the nine years that it has been surveyed, from 1997 to 2005, 479 species of fish from 46 families have been encountered on the reef.

In part, Tubbataha’s high productivity and species diversity can be explained by the reef’s natural attributes – it is offshore, remote and has a large variety of reef structures which attract a great diversity of fish. However, the MPA also contains the highest commercial fish biomass along the Cagayan Ridge. This is significant evidence that Tubbataha’s strict law enforcement is working and that, besides a handful of recorded instances of poaching, commercial fishing is not taking place within park boundaries. This research indicates that protecting a coral reef from human disturbance such as fishing can play a big role in increasing its productivity.

Jessie Beazley Reef, unprotected but located just 13 kilometres northwest of Tubbataha, seems to be directly benefiting from its proximity to the MPA. Since monitoring began in 2001, the total fish biomass of Jessie Beazley has nearly doubled. This suggests that fish, either as larvae or adults, are migrating from Tubbataha to Jessie Beazley and in this way the positive effect of Tubbataha’s ‘no-take’ policy is being spread to neighbouring reefs.

Cagayancillo, Calusa and Basterra Reef have the lowest fish biomass along the whole Cagayan Ridge. According to scientists, this is most likely due to fishing. When scuba diving on these reefs, the researchers rarely encountered mature commercial species. They conclude that many fish are being caught before they reach sexual maturity, thereby constricting their reproduction process.

Research also shows that fishing practices around Cawili has been sustainable. Despite the presence of a fishing village, Cawili enjoys the highest fish density among all the sites along the Cagayan Ridge. The study shows that even with a population of roughly 2,000 people, the community manages to benefit from the surrounding waters without devastating the reef.

Seabird research

Experts have estimated that there are roughly 30,000 seabirds regularly roosting and breeding on islands in the central Sulu Sea. Among these are Red-footed Boobies, Black Noddies (Anous minutes worcestri), Sooty Terns (Sterna fuscata nubilosa)  and various kinds of Frigatebirds. This is a good indicator of the health of these remote island ecosystems. In order to roost and breed, seabirds need intact habitats with a good supply of food such as squid and small fish. Seabird populations have dramatically declined in Southeast Asia since the end of World War II. Many species and populations have disappeared from most of their former breeding ranges and, in most cases, there is a threat that they may vanish from the region altogether. In 1995, the Masked Booby was declared regionally extinct. Other species are feared to follow this fate.

Tubbataha’s North and South Islets are among the last breeding strongholds for seabirds in Southeast Asia. Thousands of terns and boobies nest here, laying their eggs in the sand. In the past, the birds have suffered as they are extremely vulnerable to exploitation. Fishers and divers would roam around the islands, disturbing the birds and often stealing their eggs. The park has declared these islets off limits, but the damage has already been done. In the late 1970s, Ipil-Ipil trees were planted on the North Islet by Cagayanon fishermen. These trees have multiplied and now cover around 40 per cent of the limited land area. Because of this, the ground-breeding seabirds have been deprived of their natural habitat – an open space essential for nesting in the sand.

In 2003 and 2004, the critically endangered Christmas Island Frigatebird was reported on Tubbataha’s North Islet. Experts have suggested that Tubbataha is among only three areas in the Sulu Sea region that will be able to sustain seabirds in the long term. Among these areas, Tubbataha’s remoteness and protected status make it the most promising. In this respect, the marine park is vital to the country’s seabird populations, in particular the declining population of brown boobies and the Philippine sub-species of Black Noddy, found nowhere else in the world.

Seagrass research

Seagrasses are of great importance and are known to make up some of the most productive ecosystems on earth. They are flowering plants which had adapted to the marine environment. Most species are found in tropical waters, especially in the Indian and Western Pacific Oceans. Only 58 species of seagrass have been documented worldwide and the Philippines is known to contain 16 of these - or 27 per cent of all known seagrasses. Ten of these types of seagrass have been found in sites along the Cagayan Ridge.

Seagrasses form beds which can cover extensive areas of coastal waters and perform a wide array of functions for the marine environment. They are primary producers - able to use carbon dioxide in the water for photosynthesis - and are a source of food for many marine organisms. Seagrass beds also serve as breeding and nursery grounds for a range of creatures. Some reef fishes live in the seagrasses until they reach maturity and others return to them in order to breed.  Another role is to provide shelter for both transient and migrant marine organisms.

Seagrasses are important for stabilising the seabed. Strategically located between coral reefs and mangroves, they provide nutrients to these neighbouring ecosystems whilst absorbing and reducing current and wave impacts.

The distribution of seagrass species depends on the physical environment in which they are found. Seagrasses are affected by wave action and water currents, the types of sediment found on the seabed, the depth and clarity of the water and the light penetration through the water. The development of the seagrass community is also a key factor for their continued growth.

The sand flats on the eastern and western edges of the North Islet are dominated by the species Halodule and  Halophila. These areas are exposed to the impacts of strong monsoon winds and are therefore prone to sand movement. Halodule and  Halophila are fast-growing seagrasses and are quick to colonize the open spaces which such sand movement creates. The seagrass bed of the South Islet is more diverse. This could be due to the fact that it is exposed only to the weak southwest monsoon and is therefore relatively sheltered. This has enabled larger, slower growing species to grow and, as colonisation continues, may result in a mixed bed of seagrasses.

There are also anthropogenic factors which can affect seagrasses. Research has shown that seagrasses have generally been unappreciated by people all over the world. Their importance is overlooked and they are perceived as an eyesore, especially in areas being developed for tourism. Because of this, seagrass beds may be purposefully destroyed or they may suffer from trampling, gleaning, sedimentation or pollution.

However, due to its isolation and protected status, the seagrass beds of Tubbataha are largely free from human disturbances. The main factors which shape their community structures are environmental. Tubbataha’s seagrass beds are exposed to high wave or current energy, and this explains the absence of any shallow rooting species.

Marine mammal research

Tubbataha is an important habitat for marine mammals, or cetaceans, such as dolphins and whales. Unlike other surveys on the reef, cetacean surveys are carried out infrequently - in 1993, 2000 and 2004. However, thanks to these studies, researchers have identified at least nine species of marine mammal living within the park, including three types of dolphins and four kinds of whale sighted during the 2004 survey. This is more than half the number of species found in the entire province of Palawan, suggesting that Tubbataha is a significant habitat for cetaceans.

The long-snouted spinner dolphins are the species commonly encountered by the researchers. They are characterized by  their long beaks, distinct dorsal fins and their tendency to perform acrobatics. Scientists have recorded some rare events such as when a group of Fraser’s dolphins attempted to join a group of Risso’s dolphins. A short-lived fight between the two groups ensued during which a Risso’s dolphin head-butted a Fraser’s dolphin and eventually chased the group away.  The International Union for the Conservation of Nature (IUCN) has classified most of the species of whales and dolphins found in Tubbataha as ‘data deficient’. It is therefore important that more research is carried out to fill these knowledge gaps and help in marine mammal conservation efforts.

In 2004, the research team reported seeing all seven species of whale and dolphin that they encountered with at least one calf. This is encouraging as it shows that the marine mammals of Tubbataha are reproducing.

Within the marine park, the whales and dolphins are relatively safe. However, there are still threats caused by non-biodegradable waste like plastic, which is carried by ocean currents to Tubbataha. Marine mammals die once they ingest these matters which are sometimes mistaken for food. The whales and dolphins can also be troubled by excessive boat traffic or become caught in the fish aggregating devices or other fishing gears which lie just outside park boundaries.

Another threat to Tubbataha’s marine mammals was the decision of the national government in 2000, to open parts of the Sulu Sea oil and gas exploration. It is thought that the area may hold commercial deposits of oil and gas. We do not know the exact effect that such exploration and future drilling may have on whale and dolphin populations and the TRNMP management must therefore be prepared to mitigate the potential environmental risks of such a venture.

To gain further knowledge on species found in the area, it would be useful to conduct surveys throughout the year. However, sea conditions are not suitable for boat-based surveys for much of the year. Researchers have therefore suggested land-based cetacean surveys from the Ranger Station on the North Atoll and the Lighthouse on the South Atoll. This would provide an opportunity to obtain further information, especially on the seasonality of the occurrence of marine mammal species in TRNMP.

Useful websites  

ASEAN Regional Centre for Biodiversity Conservation                           www.arcbc.org

CMARIS (Coastal & Marine Resources Information System)                 www.cmartis.net

IUCN  - The World Conservation Union                                                www.iucn.org

Palawan Council for Sustainable Development                                      www.pcsd.ph

Ramsar  - The Ramsar Convention on Wetlands                                  www.ramsar.org

UNESCO                                                                                             www.unesco.org

WWF Philippines                                                                                 www.wwf.org.ph

 This article was originally published as an illustrated booklet by The World Wildlife Fund-Philippines

CLICK HERE TO VIEW PICTURES

back