Salm, R.V. and Coles, S.L. (2001) CORAL BLEACHING AND MARINE PROTECTED AREAS. Technical Report.

Download (3641Kb)


    Both TNC and WWF have biodiversity conservation as the central pillar of their missions. Each organization is deeply concerned about the potentially severe impact of repeated mass coral reef bleaching that is linked to the El Niño Southern Oscillation (ENSO) events, and is striving to find ways to mitigate the related mortality and loss of biodiversity at scales that are meaningful in the face of widespread bleaching events. In that context, this meeting was convened to address the following problem: Is there anything that can be done to change the usual approach to coral reef conservation radically enough to influence coral reef survival at a global scale, despite mass bleaching? When viewed from the perspective of reef management and conservation, these mass bleaching events are challenging, to say the least, and those who work in this field might feel powerless to act at scales that will make a significant improvement. One of us (Rod Salm) first started grappling with this challenge in 1990 while tracking coral bleaching in the Sultanate of Oman and continued in 1998 with the bleaching that hit Kenya and the Seychelles Islands. It was during his visits to Indonesia, Palau, and Papua New Guinea in 1999 and 2000 that patterns seemed to emerge. The literature contributed, too—not by the studies presented, but by those that were left out. Authors omitted certain sites from their studies, such as channels through reefs, because these showed low levels of or no bleaching, and consequently held little interest for their research. Three things became apparent when considering ENSO-related bleaching. First, there appeared to be a collection of environmental factors that, working together or individually, could reduce the susceptibility of corals to bleaching and related mortality. This was interesting as it had the potential to enable predictions of where reefs or parts of reefs with one or more of these factors present would survive a bleaching event. Second, ENSO-related bleaching shows little respect for MPA boundaries—even the most effectively managed MPA is vulnerable to coral bleaching and massive mortality. The implication of this is that we cannot rely on current methods of reef protection and management to bail us out of the bleaching crisis. This was recently underscored on Ngeruangel atoll in the far north of the island nation of Palau. The people of Kayangel State (all of whom live on one atoll) established Ngeruangel atoll, some seven miles away as a total reserve in 1996. Their own conservation officers patrol the area to keep out fishermen and other unauthorized visitors. Ngeruangel is remote. If there are any impacts of people on the reefs of the atoll, they are few and likely to be very minor. But the corals of Ngeruangel were highly impacted by the 1998 El Niño bleaching event, and there are huge fields of enormous staghorn corals in the atoll lagoon that remain dead and covered by sponges and algae. This is a perfect example of how a remote, well-protected area fell victim to bleaching. Third, if indeed we can isolate environmental factors that render certain reefs or components of reefs less susceptible to bleaching-induced mortality and can demonstrate that these sites do survive subsequent bleaching events, we should be able to design our management to ensure adequate protection of these sites. For example, it should be possible to zone parts of larger MPAs, which have biodiversity conservation as an objective, to ensure high levels of protection for reef communities that consistently appear to resist bleaching, recover quickly, or have one or more environmental factors present. In some cases, luck rather than strategy or deliberate planning might already have assigned high levels of protection to the right places, such as the coral communities in Komodo National Park, which are influenced by cool water upwelling and mixing by strong currents. An understanding of these environmental factors and their role in bleaching resistance and resilience potentially adds another important piece to our scientific tools for selection, design, and management of MPAs. A global review of all coral reef MPAs to assess their management strategies in relation to coral bleaching should be considered as a follow- up to this workshop. Such a review should be conducted in concert with a review of other established considerations in MPA design, such as comprehensiveness, adequacy and representativeness, among others. These ideas were presented during the 9th International Coral Reef Symposium in Bali to a group of both reef scientists and managers and received considerable encouragement from both. It is clear that people are concerned about what we can do to mitigate the impacts of ENSO-related bleaching on coral reefs at scales that are meaningful. The ICRS participants acknowledged that direct interventions are labor intensive, expensive, and very limited in scale for this purpose, and were receptive to the idea of using MPAs as a means to protect areas that survive or rapidly recover from coral bleaching. During the discussion following the Bali presentation, Billy Causey noted that there are discrete reefs in the Florida Keys National Marine Sanctuary that survive bleaching year after year and the fact that these sites receive no special levels of protection is an issue that needs to be addressed. Protecting sites of low susceptibility to bleaching may not be enough. We also need to create conditions that enhance recovery of the susceptible areas. This means adequately controlling other stresses in the recovery sites to maintain conditions suitable for rapid recovery, and ensuring that that the resistant sites are upcurrent of the susceptible areas so as to enhance larval recruitment. This leads us into the bigger picture of larval dispersal, recruitment, and the connectivity among reefs. Ultimately we must consider these factors in a global network of coral reef MPAs to ensure survival of representative biodiversity of coral reefs. A global network of interconnected reef reserves that are designed to survive and managed to be mutually replenishing is an admirable goal to pursue, even if the network will be completed and its success measured many decades after our lifetimes. In summary, we are faced with the challenge of thinking at three different scales: 1) the local scale of different reef environments and habitats within MPAs; 2) the medium scale of factors and actors that can influence environmental conditions for recovery within a MPA; and 3) the distribution of MPAs at a global scale, with respect to global environmental and biodiversity patterns. This workshop is just one step in the direction of determining what more it takes to design coral reef MPAs to survive. We should focus on practical, immediate measures that MPA practitioners can adopt. But we should be mindful of the larger context and longer time-scales that we must consider in order to establish a truly sustainable global network of coral reef MPAs. Once we have synthesized the most current thinking and information into a draft set of additional MPA selection criteria, design principles, and management guidelines, we will need to present these to a wider audience for global application, testing, and refinement. Our approach focuses on confirming what, if any, predictable environmental determinants exist that would decrease the susceptibility of reefs or parts of reefs to bleaching related mortality. The approach also outlines an appropriate global research and monitoring program to test this possible relationship. We propose that this approach should inform the definition of additional selection criteria, design principles, and management guidelines for coral reef MPAs to complement those that already exist. We believe that changing the way we select, design, and manage MPAs can make the difference needed and we are committed to taking our outputs forward and promoting them around the world, together with any other willing partners.

    Item Type: Technical Reports (Technical Report)
    Related URLs:
    Publisher: The Nature Conservancy, Asia Pacific Coastal Marine Program
    Keywords: coral bleaching, marine, MPA's, protected, bleaching,
    Subjects: (C) Ecosystems > (CB) Marine > (CBA) Coral Reefs
    (H) Protected Areas > (HD) Marine Reserve
    Publication Sources: (3) Other Source > (3B) NGOs
    Date Deposited: 18 Nov 2010 15:11
    Last Modified: 20 Jan 2011 14:52

    Actions (login required)

    View Item