Coral Reef Resilience: The Impact Of Reef Management And Restoration Efforts

Introduction

Background on Сorals and Threats to Its Biodiversity

Corals, often mistaken as plants, are marine animals that exhibit plant-like characteristics. Taxonomically, they are classified under the class Anthozoa, phylum Cnidaria, and order Alcyonacea for soft corals, or order Scleractinia for hard corals. Corals reefs are composed of tiny coral colonies, within these colonies are polyps, and within these polyps are the microscopic algae that live symbiotically within them. Both species symbiotically thrive because of their mutualistic relationship: as the coral benefits from the algae’s byproduct of photosynthesis, such as oxygen and food, the algae in turn profits by using the coral’s metabolic wastes for their own photosynthetic process and using the coral itself as a protective housing.

Owing to this unique and clever coral-zooxanthellae relationship, along with the various organisms residing in coral communities, coral reefs are known to have very rich biodiversity (Dumas et al., 2009). Their high biodiversity and productivity make them one of the most important ecosystems, often being compared to tropical rainforests. According to DOST-PCAARRD, the Philippine reefs are one of the most diverse because it is located at the heart of the coral triangle, with 915 reef fish species and about 400 scleractinian coral species, ranking as the largest reef in Southeast Asia.

Coral reefs serve as protection and food source to many marine species and offer numerous ecosystem services to humans such as sources of livelihood, food, medicine, coastal protection and the like (Smithsonian Ocean Portal, 2016). When the reef’s worldwide ecosystem services are combined, it is estimated to be worth $375 billion yearly – bringing great impact to everyday human life

However, due to the numerous stressors that destroy the corals, their biodiversity is declining, along with the services that it provides. These stressors include global warming, ocean acidification, and predation. Although these climate-related factors pose a threat to corals, its impact is exacerbated by human intervention (Hill and Wilkinson, 2004). Other major coral threats are from anthropogenic activities such as destructive fishing methods, overfishing, untreated wastewater effluents, sedimentation, coastal development, human settlement, and recreational activities. Among these said factors, today fisheries are the greatest threat to the coral reefs in the Philippines.

The increase of coral decline made coral rehabilitation one of the priority researches as several scientists have come up with different ways of restoring the health of reefs with the main objective of assisting the recovery of a destroyed reef as close to its original state, as possible. Thus, efforts in coral rehabilitation bring hope in improving the resilience of the reefs towards the said stressors.

In this term paper, several coral management efforts and restoration techniques will be evaluated in terms of their efficacy. The aim of this paper is to investigate the widely used restoration actions implemented in the Philippines along with their success rates. Moreover, this will shed light on solutions, as which method holds big promise to the future of our reefs.

Significance of the Paper

Coral reef communities in the Philippines bring massive ecosystem services such as livelihood, food, medicine, coastal protection, and the like. However, the biodiversity of Philippine reefs is threatened as anthropogenic activities are on the rise – this, coupled with climate change will intensively result in their degradation. Thus, protecting the reefs is so important and calls for the need for effective management and restoration efforts in order to improve reef resilience.

Today, researchers are developing and improving techniques in reestablishing coral communities. Investigating the management efforts and techniques that have been tested in situ provides us information on what restoration method brings greater promise to be able to meet with the increasing demand for coral reef restoration.

Objectives of the Paper

Generally, this term paper aims to investigate the widely used restoration actions implemented in the Philippines along with their success rates. Specifically, it aimed to evaluate the efficacy of management efforts and to weigh which management efforts have the greatest impact on improving reef resilience.

Results and Discussion

Coral Rehabilitation Actions in the Philippines

In the year 2012, a coral reef restoration project was launched by the Department of Science and Technology (DOST) and the Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development of the DOST (DOST-PCAARRD), called “Filipinnovation.” The project aimed to improve coral productivity for fishing sustainability. The Filipinnovation project used asexual reproduction approach using the coral transplantation technology wherein live coral fragments that are detached from their colonies, called “corals of opportunity” (COPs) are collected and transported to a coral nursery unit (CNUs). In the CNUs, COPs are monitored and left to recover and regenerate and later to be transplanted in degraded coral reef sites. The CNU design uses marine epoxy clay, nails, and cable ties, holding 500 COPs per batch. The project deemed successful in 2013 as it had established a total of 538 CNUs and transplanted 487,158 coral fragments. After the Filipinnovation project, the same technology was continually used by the National Coral Reef Rehabilitation Roll-Out to restore degraded coral reefs across the country in Ilocos Norte, Pangasinan, Bataan, Zambales, Palawan, Bohol, Zamboanga City, and Sarangani. In addition, the same transplantation technology was used in 2015 during the fifth Asia-Pacific Economic Cooperation Policy Partnership on Science, Technology, and Innovation (APEC PPSTI-5) culminated in Boracay (Carlos et al, 2016).

To date, there are also ongoing projects such as the project is by Southern Cross University, led by Dr. Peter Harrison with project code FIS/2014/063. This project’s goal is said to restore the damaged coral communities in Australia and the Philippines using the mass coral larval reseeding technique to improve food security and reef productivity. They anticipate that the reseeded corals will reproduce sexually after 1-4 years thus promoting local reef resilience. It started last July 1, 2015, and is expected to end on June 30, 2020.

The reseeding technique is aided by a robot called LarvalBot. LarvalBot, about the size of a briefcase, strolls along the reef sites and “reseeds” corals with thousands of larvae. According to Dr. Harrison, LarvalBot was tested at Vlasoff Reef, Australia and in the trial, the robot dispersed 100,000 coral larvae in the area. However, results are yet to be seen as it takes time for the coral larvae to settle (Chow, 2018).

Aside from restoration techniques, management efforts are also implemented in the Philippines in the form of Marine Protected Areas (MPAs). MPAs are any specific marine area that has been held in reserve by law or other effective means and has broad management plans on fisheries, recreation, and pollution control to protect the entire or part of, the enclosed coastal and marine environment. Restricting human activity in MPAs allow the marine environment to be left undisturbed and thus, species flourish and resources replenish. This protects the critical spawning stock biomass to ensure spillover. The spillover effect is said to be one of the most important features of MPAs since it allows the migration of adult or juvenile fishes from the sanctuary or MPA to the fished areas or non-MPAs, maintaining a sustainable fishery.

According to Karin Post of Marine Conservation Philippines, there are three kinds of MPAs namely: (1) Marine Reserve, (2) Marine Sanctuary, and (3) Marine Park. A Marine Reserve is kind of MPA where strict conditions are not mandated for the entire area. There are some zones that allow but at the same time controls activities such as fishing and recreation. A Marine Sanctuary is an MPA that has full control and prohibition on all kinds of human activities. Whereas a Marine Park is a kind of MPA that restricts fishing but allows recreation. It is usually focused on education and preservation. To date, there are 372 MPAs in the Philippines with a total area of 10,724 km2.

Most Promising Restoration Efforts Towards Reef Resilience

In an interview with Dr. Harrison last August 31, 2018, by the Reef Resilience Network, he disclosed the partial results of his Larval Reseeding project. Partially, it was said that there were eight successful coral larval restoration sites; five in the Philippines and three in Australia. Their methods include the capture of coral spawns in situ, rearing them in the laboratory to get high rates of fertilization and raising millions of larvae each year to be reseeded in the degraded coral reef areas, increasing natural recruitment in the said reef area. Dr. Harrison revealed that they had achieved a record of the fastest growing Acropora species. Normally, it would take about three years for the branching coral to reach sexual maturity but in Dr. Harrison’s project, the Acropora sp. reached breeding age and size for only two years. He also highlighted that this method is more promising than 95% of restoration projects that use fragmentation technology.

The results of the fragmentation-transplantation technique were indeed of a low success rate as it was also noted during the APEC-PPSTI-5. After a month of planting the transplanted fragments in Boracay Island, DOST, Sangkalikasan, and PCG documented the survival of the COPs. It was observed that there was no dramatic increase in the growth but at least the COPs fully settled in the substrate, indicating that they stand a chance in survival.

In addition, perhaps the low success rate of coral transplantation lies in the way the corals were handled from capture to replanting. In an interview with Rappler, Dr. Wilfredo Licuanan of the De La Salle University said that the transplantation depends on 'planting the right coral species in the right areas.” It is indeed a core requirement to know where to place these corals because, like plants, some species produce chemicals that may have allelopathic effects on the neighboring corals and like plants, coral species grow specifically in their optimal reef environments and conditions.

Conclusion

The efficacy and success rates of Larval Reseeding technique outweigh those of the Transplantation technology. Larval reseeding resulted in a high growth rate than those corals that were transplanted. However, the former was only successful in fast-growing species such as branching corals. In coral restoration, it is indeed a “one size doesn’t fit all” case. More studies are needed in order to address which technique or technology best fits a certain coral species in a certain area.

In the case of Marine Protected Areas, strategic environmental rules, plans, and strategies should be established along with its strong enforcement should be maintained in order for the marine area to be properly monitored and protected. Education to government workers and conservationists, intensive coral research by institutions and agencies, and information dissemination to the local fishermen and even to the laymen is also crucial in maintaining MPAs as it increases awareness and motivates communities to be involved in improving reef resilience.

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