VULNERABILITY AND RESILIENCE ASSESSMENT OF TUBBATAHA REEFS NATURAL PARK, CAGAYANCILLO, PALAWAN, PHILIPPINES

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1 VULNERABILITY AND RESILIENCE ASSESSMENT OF TUBBATAHA REEFS NATURAL PARK, CAGAYANCILLO, PALAWAN, PHILIPPINES Ma. Theresa R. Aquino, Rowell C. Alarcon and Maria Retchie C. Pagliawan 1 Rationale Tubbataha Reefs Natural Park (TRNP) is internationally renowned for its ecological importance and aesthetic value. It provides important ecosystem services, which underpin Filipinos with its resultant economic benefits and incalculable social values. In combination, the social-ecological system centered on the reef is extraordinary in its importance and complexity. Unfortunately, it is not totally safe from issues that threaten its stability such as climate change and illegal fishing, to name a few. Thus conservation efforts have to be prioritized and hastened to counter degradation and maintain ecological balance to assure food security and ensure that future generations will experience all the wonders of a rich habitat such as Tubbataha Reef (Ledesma et al 2009). TRNP is the largest coral reef atoll in the Philippines and the first purely marine World Heritage Site in Southeast Asia. TRNP harbors a diversity of marine life equal to or greater than any such reef of its size in the world. As of the latest surveys, it has been found to harbor at least 360 species of corals (representing 80 out of 111 genera known in the world), 7 species of sea grass, 66 species of algae, over 600 species of fish, two species of marine turtles, 12 species of sharks, 13 species of cetaceans and around 100 species of seabirds. Rays and skates are also commonly seen around the reefs. Pelagics such as tuna, mackerel, jacks and barracudas are observed in schools near the reef crests. In the Southeast Asian context, TRNP represents the only known breeding area of the Philippine endemic subspecies of Black Noddy (Anous minutus worcestri). It is also one out of about four major remaining breeding areas of Sooty Tern and Brown Noddy, and the last known breeding area of Masked Boobies in the Philippines, and probably in Southeast Asia. Most of the seabird species breeding at the Tubbataha Reefs can be considered threatened on the national and regional levels. One globally critically endangered but migratory seabird species also occur: the Christmas Island Frigatebird Fregata andrewsi (Jensen 2010). Philippine reefs are not the only reefs at risk. Southeast Asian reefs continue to face development and exploitation in spite of greater awareness of their ecological and economic importance (Ledesma et al 2009). With the growing human population, the lack of education, poverty and unsustainable fishing practices leave the country s surrounding waters in a critical state. Its continuing degradation will ultimately decrease the productivity of our coastal waters, leaving an unstable future for the country s food security. The potential for increasing economic growth through tourism also decreases as the destruction of the reefs continue. Climate change is a new challenge that is truly global in scale. While few systems are likely to benefit from climate change, coral reefs are particularly vulnerable. Mass coral bleaching events, resulting when sea temperatures become unusually hot, have already caused serious damage to over 16 percent of the world s coral reefs (Wachenfeld et al 2005). Understanding the vulnerability of such a large and intricate system to climate change is a particularly difficult challenge. Local environmental issues make the reefs within Tubbataha ideal as a case study for the application of the resilience assessment framework. This study, based on Maynard et al. (2010), is a valuable tool for assessing the resilience of coral reefs. Its use will help management understand the 1 Tubbataha Management Office, 41 Abad Santos Street, Puerto Princesa City, 5300 Palawan, Philippines

2 current condition of TRNP, thereby allowing the same to act appropriately to ensure ecosystem resilience to current and potential threats such as climate change. This exercise was conducted to assess the vulnerability and resilience levels of Tubbataha Reefs Natural Park and to recommend management policies and actions that can improve its resilience to threats such as climate change. Methods Tubbataha Reefs Natural Park is situated in the middle of the Sulu Sea (N 8 50'677 E '734 ) and covers a total area of 97,030 hectares plus a 10-nautical mile perimeter buffer zone. The park is composed of two coral atolls separated by a 5-nm channel with Jessie Beazley Reef located about 14 nm north of South Atoll and about 10 nm northwest of the North Atoll. The oblong-shaped North Atoll is 10 miles long and three miles wide enclosing a lagoon of sand and corals 24 meters deep. The South Atoll is a triangular reef structure about 9 miles long and 2 miles wide. Portions of the atolls shallow coralline reef platforms are exposed at extreme low tide. The reef systems are composed of continuous reef platforms meters wide, completely enclosing sandy and coral substrate lagoons that range from 1-40 meters in depth. The reef platform deepens at the outer reef flat and reef crests. It ends in steep, often vertical, walls on the seaward side. On the inner side of the platform are shallow reef flats and sea grass beds with a deeper lagoon in the center (Figure 1). An islet found in the north atoll, approximately 1.3 hectares, harbors more than 17,000 seabirds and is also an important nesting ground for sea turtles. Situated in the southern part of the south atoll is a smaller islet, roughly 0.28 hectares, where a lighthouse stands. Figure 1. Map showing the three reef formations found in TRNP. For purposes of this study, the park was divided into three sites North Atoll, South Atoll and Jessie Beazley Reef. Previously existing scientific data collected from 1998 to 2008 was used in the assessment. This study employed the coral reef resilience assessment method of Maynard et al. (2010). The assessment tool includes 19 resilience indicators, which were based on their influence on ecological processes, anthropogenic impacts, biological variables and physical variables. This study applied the indicator justifications used in Maynard et al. (2010), except for the water pollution/contaminants indicator, where the authors considered solid waste instead of pesticides, nutrients and pathogens, since these are the more predominant type of pollution in the park.

3 Unknown Not really Somewhat Certainly Unknown Not really Somewhat Certainly Table 1. Resilience assessment framework by Maynard et al. (2010). Indicators were posed as questions to reduce ambiguity. Broad-scale Resilience Indicators Are neighboring upstream reefs close enough to this site to provide larvae for recolonisation following disturbance events? Has the site been exposed to hot water events previously and survived and/or recovered quickly? Is the site free from contamination/pollution (e.g. nutrients and wastes)? Are factors present that work to increase water movement and promote mixing (e.g. Peninsulas/channels, large tides, exposure to winds and waves)? Is the site free from physical impacts (e.g. Storm damage, mining/extraction, destructive fishing)? Is this site impacted by upwelling? Is the site free from fishing pressure? Are factors present that work to reduce incident light (e.g. High islands, proximity to river outflows/sediment plumes)? Local-Scale Resilience Indicators Is coral cover at this site higher than at other site in your analysis? Is the coral community made up primarily of resistant/tolerant coral species? Are herbivores (e.g. Fish, urchins, molluscs, turtles, etc.) abundant at the site? Are mature (large) coral colonies abundant at the site? Is there a high availability of hard substrate suitable for coral recruitment? Is the site free from other physical impacts (e.g. Anchor damage, dive/snorkel, fin damage)? Do corals at the site stay submerged at low tide? Is bioeroder abundance extremely low at the site? Does the site have topographic complexity (e.g. Gullies, ridges, large range in coral sizes and morphologies)? Is the site free from sedimentation? Is coral disease abundance extremely low at the site? Results of the assessment of the three sites were then compared and analyzed initially between sites. The average of the three sites was then compared with the findings of the study of Maynard et al. (2010) in the southern Great Barrier Reef. Results and Discussion The results of the assessment are presented in the table below. Comparing the three sites, North Atoll ranked the highest in resilience at 85 and Jessie Beazley the lowest at 64. The South Atoll garnered a score of 81, bringing the average for these three sites at The difference in scores might primarily be due to the discrepancy in size of the coral reef formations. The Jessie Beazley reef is barely one percent of the size of either the North or South Atolls thus its resilience would be comparatively lower than these two. In addition, the levels of protection afforded to the three sites over the years have not been equal. Neither is the proximity of these sites to the ranger station ergo the ease of patrolling the areas. The big discrepancy in the level of protection given to Jessie Beazley could be accounted for by the fact

4 that it was only in 2006 that the area around this reef was added to the park. Prior to that, illegal fishers attempting to enter the park at night or early morning were known to often rested at the emerging cay of Jessie Beazley while waiting for darkness to fall. Evidences of their presence were often seen by researchers covering the area. Table 2. Results of the assessment of the three sites in Tubbataha Reefs Natural Park using the framework described by Maynard et al. (2010). JB NA SA Average Broad-scale Factor Connectivity Hot water events Free from contaminants/pollution Water mixing Free from physical impacts Exposure to upwelling Free from fishing pressure Reduction in Light Stress Local-scale Factor Coral Cover Resistant/tolerant species Abundance of herbivores Abundance of mature corals Substrate availability Free from anthropogenic physical impacts Coral submersion Absence of bioeroders Topographic complexity Free from sedimentation Absence of coral disease The study done by Villanoy et al. (2002) describes the Sulu Sea as a type of transition area between the South China and Sulawesi Seas. Strong horizontal wind variations from the Mindoro Strait, Balabac Strait and Sulu archipelago, at times, create upwelling and downwelling events that influence primary productivity and thus has a large effect on the concentration and distribution of fishes and other marine life including cetaceans inside the TRNP. The predominantly westward movement of ocean currents in the Sulu Sea was initially hypothesized to transport fish eggs and larvae to the eastern coast of Palawan (Dolar, L & Alcala, A. 1993), ensuring the sustainability of fisheries in mainland Palawan significantly. This theory was confirmed by the study on connectivity conducted by Campos et al. (2008) showing TRNP as source and sink of fish and decapod larvae to the eastern coast of Palawan, enriching fisheries in the area. These include commercial fish species such as tunas, jacks and groupers. The resilience of reefs is inextricably linked to factors that influence the growth, reproduction and survival of key functional groups on coral reefs. The assumption is that well-connected reef systems generally take 10 to 20 years to fully re-establish after a massive disturbance (Fabricius et al 2007). No massive disturbances have been recorded since the first coral survey conducted in TRNP in 1984 (White and Palaganas 1991). The most extensive damage so far was recorded during a bleaching event due to the El Niño cycle in According to the research carried out by the World Wide Fund for Nature- Philippines (WWF) and the University of the Philippines-Marine Science Institute (UP-MSI), TRNP lost

5 about 21% of its coral cover. However, TRNP managed to recover faster than in places where human pressure was intense (Songco, A. & Jack, K. 2009). Nevertheless, there are adjacent reefs to TRNP, such as Basterra and Cagayancillo reefs, which could provide larvae for recolonisation should other destructive events occur in the park. A few incidents of coral damage due to anchoring were recorded in the park. To mitigate this, mooring buoys were installed and used by boats during the dive season from March to June. Tourism (which only allows diving) and research are the only activities currently allowed in TRNP. Certainly the presence of divers has impacts on the corals and marine animals; however, a study to quantify and assess divers impact on the reefs has yet to be conducted. Occurrence of coral diseases has not been noted in TRNP but is a threat that is being closely monitored by management. However, this is a difficult proposition given the size of the coral reef area. It is feared that detection might only be possible if such diseases have already occurred in a significantly large area. In Maynard et al. (2010), water pollution referred to pesticides, nutrients and pathogens that are normally generated from land-based sources and cause coral disease increasing the likelihood of bleaching. TRNP currently does not have data on contaminants and is remote and therefore far removed from land-based sources of these contaminants/pollutants. Thus, in the interpretation of the criterion contaminants/pollution, the authors expanded the definition to include non-biodegradable waste such as plastics which emanate from outside of the park boundaries. Non-biodegradable plastics might not necessarily cause coral disease or bleaching but these could still contaminate the water by releasing polystyrene by-products which are suspected carcinogens and bisphenol A, a reproductive disruptor (American Chemical Society 2010). Thus, in interpreting the question on contaminants, plastics and other non-biodegradable waste were considered in place of pesticides, thereby affecting the results to a large extent. Overall, the assessment showed that TRNP has moderate resilience, a rating only slightly higher than that of the sites studied by Maynard et al. (2010) in the Southern Great Barrier Reef. To what degree the results of the two marine protected areas can be compared, however, would be highly debatable. For one, the assessors are not the same in the two areas and thus would have their own inherent biases and/or errors. Secondly, there is a very strong difference in the habitat type found in TRNP and that of the Southern Great Barrier Reef. Furthermore, the number of sites in the two MPAs varied greatly three for TRNP and 31 for the Southern Great Barrier Reef. Such discrepancies in the conditions of the MPAs preclude the possibility of a useful comparison. TRNP scored the lowest in the local-scale factor presence of resilient coral species since this data was not available at the time of assessment. Coral surveys conducted in TRNP in the past had only identified life forms and not species. Thus the authors had no way of knowing what percentage of the coral cover were resilient species. Low scores were likewise garnered in the local-scale factor due to the fact that a large area of the park is made up of shallow reefs that are exposed during low tide, hence its name Tubbataha. This moderate resilience rating of TRNP underscores the fragility of the park and the need for the furtherance of its protection. The moderate results showed that TRNP management policies and actions need to be improved on or strengthened to increase the resilience of the park to impacts of climate change. Maynard et al. (2010) pointed out that, of the 19 indicators, four are responsive to improved management action, namely (1) fishing pressure, (2) water pollution, (3) sedimentation and (4) anthropogenic physical impacts. In the case of TRNP, water pollution emanates from outside of the boundaries of the park and will thus require intervention at a higher level of management than that of the park. Waves and wind carry sand from the

6 islets and cays to settle on the corals. This is the cause of the very minimal sedimentation which can be observed in the park, and is a natural occurrence, thus beyond management control. A noticeable increase in sand movement has been documented in the past years. The continued erosion of the Bird Islet and the emergence of numerous cays in the reef flats of the atolls are a testament to these shifts. Likewise, in 2009 the ranger station sandbar, normally located about 20 meters east of the ranger station (Figure 2) shifted right underneath the structure, an incident that has not occurred in the last nine years of the station s habitation. This unusual condition (Figure 3) lasted for about two months, from August to October where the prevailing wind is Southeast Monsoon, before the sandbar moved back to its original location. Figure 3. Photo of the Ranger Station showing the elevated position. Photographer was positioned at the sandbar. January 2009 Figure 2. Photo taken of Ranger Station on 16 October 2009 showing the sandbar shift which engulfed the stilts of the station. Summary and Recommendations In view of these considerations, TRNP management could still improve resilience of the park by ensuring that it is free of fishing pressure and other anthropogenic impacts. Sustained enforcement of park rules and regulations could help increase compliance and lessen anthropogenic impacts. More intensive awareness programs for users of the park, i.e., tourists, dive boat operators, crew, and dive masters should be implemented. Further increasing the role of dive boat operators and dive masters in enforcing the park rules and regulations among their guests could help ensure compliance and lessen impacts on the park. The result of this assessment also emphasized the need to generate more refined research data. Although having more than a decade s worth of comparable data is most desirable and has proven useful these past years, there is a need to identify, up to the species level, some of the marine life in TRNP especially those that are critical to the study of climate change impacts. In the case of corals, there is a need to determine whether those that are found in the park are predominantly resilient species or not. While it helps that the authors are familiar with the site to be assessed, being an integral part of its management, it is unavoidable that some bias may be present in answering the questions. Thus, in future assessments, it might be more accurate to include non-members of the management staff in the group of assessors.

7 The method of Maynard et al (2010) was well replicated and tested in a lot of areas. However, there are some aspects in the management of TRNP that are not fully addressed by the method. Thus, it might be helpful to develop a vulnerability assessment tool that would better fit the conditions of TRNP. References: American Chemical Society Hard plastics decompose in oceans, releasing endocrine disruptor BPA. ScienceDaily. /releases/2010/03/ htm Campos L., Beldia II P., Villanoy C., and Aliño P Using Ichthyoplankton Distribution in Selecting Sites for an MPA Network in the Sulu Sea, Philippines. Proceedings of the 11th Interntional Coral Reef Symposium, Ft. Lauderdale, Florida, 7-11 July 2008 Dolar M.L.L. and Alcala A.C Notes on the ichthyoplankton and marine mammals of the Sulu Sea, Philippines. Silliman Journal (2). pp Fabricius K., Hoegh-Guldberg O., Johnson J., McCook L. and Lough J Chapter 17 Vulnerability of Coral Reefs of the Great Barrier Reef to Climate Change. In Climate Change and the Great Barrier Reef, eds. Johnson JE and Marshall PA. Great Barrier Reef Marine Park Authority and Australian Greenhouse Office, Australia. Jensen A Field Report: Monitoring and Inventory of the Seabirds and their Breeding Areas in Tubbataha Reefs Natural Park and World Heritage Site, May 12-16, Ledesma M.C., Jontila J. B., Dygico M. P., Aquino M.T., Songco A. M Coral Reef Monitoring in Tubbataha Reef Natural Park: Status and Trends from 1997 to WWF-Philippines, Tubbataha Project. Maynard J. A., Marshall P. A., Johnson J. E., and Harman S Building resilience into practical conservation: identifying local management responses to global climate change in the southern Great Barrier Reef. Songco A. and Jack K Tubbataha Primer 2 nd Edition. Tubbataha Protected Area Management Board Villanoy C., Silvano K. and Palermo J Tubbataha Reef and Sulu Sea Oceanographic Study. WWF- Philippines Report. Tubbataha Management Office Files Wachenfeld D., Johnson J., Skeat S., Kenchington R., Marshall P., and Jinnes J Introduction to the Great Barrier Reef and climate change. Page 3, Chapter 1. White A. and Palaganas V Philippine Tubbataha Reef National Marine Park: Status, Management Issues, and Proposed Plan. Environmental Conservation, Vol. 18, No. 2