One of the largest studies to date of coral reef protection measures warns that conservation zones are in the wrong place to protect reefs from collapse.
Research published today in the journal PLoS ONE by an international team of scientists indicates that current zones or ‘No-take areas’ (NTAs) are vulnerable to the effects of climate change.
The scientists studied 66 sites across seven countries over a decade in the Indian Ocean.
They conclude that while existing conservation zones should not be removed, new zones are urgently needed to protect coral reef ecosystems against the effects of rising temperatures.
What does this research mean for marine conservation? We asked New Zealand marine scientists to give their views.
Jeff Shima – Director of the Victoria University Coastal Ecology Laboratory, School of Biological Sciences, Victoria University of Wellington, said:
“Coral reefs are the arks of the oceans. This work by Nick Graham and co-authors underscores the need for urgent action in the tropical Indo-Pacific. Their publication in PLoS One is the latest in a growing list of scientific articles that present compelling evidence for losses of living corals across large regions of our planet. It should not come as a surprise to anyone that these losses will adversely affect the fishes and many other animals that rely upon living corals for food and shelter. But like so many effects of climate change, these changes to reefs and their occupants happen slowly (in comparison to the length of most scientific research programmes), so they are exceedingly difficult to document. One key message: long-term research programmes are imperative, and these need to be supported.
“Graham and colleagues draw upon long-term data covering a large area to paint a compellingly bleak future for coral reefs. Projected losses of corals and their associated organisms-if realised-will prove devastating for the economies of many island- and coastal nations, including many Pacific Island nations with strong cultural, social, and economic ties to New Zealand. Graham and colleagues rightly note that marine reserves-while certainly important as tools to curb effects of overfishing-won’t necessarily protect against adverse effects of climate change.
“So what is the way forward?
“Coral reefs require urgent action-not just from concerned global citizens and conservation groups who help raise awareness, but from top scientists and those who fund their work. There is still so much to learn. An understanding of how this incredibly diverse collection of species (including humans and their associated activities) respond to climate change is paramount to predicting and possibly mitigating unwanted effects. I have conducted research on coral reefs in the Pacific for more than 15 years, and I-for one-am staggered by how little we know about most species and their ecological roles-and perhaps more importantly, the potential of some of these species to respond to-, exacerbate, or mitigate other effects of climate change. If we hope to be proactive, this knowledge is essential.
“Few nations with threatened coral reefs are in a position to provision and fund the level of research that is required. Countries such as New Zealand are well positioned to support the required science. With inaction, we stand to lose nearly as much as our Pacific neighbours.”
Mark Costello, Leigh Marine Laboratory, University of Auckland said:
“Shallow-water tropical coral reefs are amongst the richest habitats on earth in terms of biodiversity, and provide an important source of food and tourism for many coastal communities. This study brings together data from 66 locations in the Indian Ocean and shows that a widespread pattern of decline of live coral was followed by a loss of fish, indicating that the integrity of these ecosystems has been lost. In other words, the loss of coral habitat results in the loss of the fish associated with it (as we would expect for forest birds should their habitat be lost).
“They did find the no-take marine reserves held much higher abundance of fish, and that the regional, climate-driven mass-bleaching of corals occurred inside and outside reserves. Thus regional scale changes in climate, for example due to sea temperature and ocean acidification, will impact reefs regardless of the type of protection they may be provided locally. The implication is that both regional (and global) scale, as well as local scale (e.g. marine reserves), control of human activities is necessary if coastal resources are to be sustained.
“A study at the University of Auckland’s Leigh Marine Laboratory (published in Science by Mora, Costello and others in 2006), found that while almost 20% of tropical shallow-water coral reefs are within so-called Marine Protected Areas, that only 2% were protected from fishing, and many are impacted by coastal pollution. Thus only 0.01% of these reefs are fully protected from human activities. Whether these pockets of diversity would be sufficient to provide fish and other species to restore the diversity of the wider reefs is unknown.
“The principle findings of this study are likely to apply to other ecosystems. That coral dominated ecosystems are common in the deep-ocean, including around New Zealand, was overlooked until the past decade. However, the very limited information on these ecosystems makes it difficult to give them the attention that the more accessible and charismatic shallow-water tropical coral reefs receive.”
Stephen Wing, Department of Marine Science, University of Otago, said:
“I think the take home message is that no-take areas can be vulnerable to large scale disturbance like climate change and that locating them in areas that are naturally resilient to disturbance is the best strategy for guarding against loss of corals and associated reef fish communities.
“One of the important contributions of community ecology to management of fisheries and biodiversity in the oceans is the idea that more intact food webs, those with abundant predators, grazers and structure forming organisms, are more resilient to change and disturbance than communities that have been degraded by over-fishing or pollution. Accordingly one of the management measures that has been increasingly used to achieve this has been marine protected areas where the direct effects of harvest are removed and communities become more intact. The article by Graham et al. makes the important point that for wide scale degradation of habitat caused by global climate change the best strategy for locating marine protected areas or marine parks is to take advantage of geographic refuges where the effects of climate change might be less and the system might be naturally more resilient. In these places the effect of removing direct disturbance from fishing would pay extra dividends in terms of the long term resilience of the community.
“In a nutshell Graham et al. have pointed out that geographic refuges exist for corals and the best strategy for insuring against loss of coral systems in the face of climate change is to protect those refuges from direct impacts of fishing et cetera as well. The article points out that one of the likely results of the loss of corals due to climate change would be the loss or decline of associated reef fish communities. These communities are the most species dense vertebrate communities on earth and along with corals would represent a tremendous loss of marine biodiversity.”
James J. Bell – Centre for Marine Environmental and Economic Research, Victoria University of Wellington, said:
“One of the major issues facing the scientific community and government agencies world-wide is how to define and implement effective strategies to manage marine resources in response to a multitude of threats occurring over different spatial and temporal scales. Designating any protected area is a complex issue and determining the ‘right’ location has rarely been based on rigorous scientific study. Instead, the designation of most marine protected areas and no-take zones, and the location of their boundaries, has been decided with an emphasis on social and economic considerations. It is important to take care when suggesting that existing no-take zones are in the ‘wrong’ place, as we should carefully consider what the original purpose of the no-take zone was, and whether the original aim has been achieved or not. This new research clearly demonstrates the complexities facing government agencies, environmental groups and researchers in protecting the marine environment from current and future threats.
“To a large extent the results of this large-scale study no surprise, since the majority of the small no-take zones considered in the study were probably not designated with protecting against the impacts of climate change in mind. Instead, most were established for the purpose of enhancing fish stocks, protecting biodiversity and allowing coral recovery. It is important to realise that for most developing nations the need to create local sustainable subsistence fisheries likely to provide food are of more concern than the effects of climate change, which may be considered to be decades away. This study highlights how some areas of reef are likely to be more resilient to the impacts of climate change than others and that different approaches may be needed to protect coral reefs from its impacts.”
To talk to these or any other scientists, please contact the Science Media Centre on tel: 04 499 5476 or email: smc@sciencemediacentre.co.nz.
Notes to Editors
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