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| Surviving the bleach |
| New report helps coral reef managers avert climate change-induced coral death |
Geneva, Switzerland, 30 November 2006 (IUCN) – As ocean temperatures continue to rise, nearly every coral reef around the globe has experienced increased levels of stress, best illustrated by “coral bleaching” – the loss of tiny algae that help corals thrive and give them their colour. Such bleaching events have increased in frequency, scale and intensity over the last two decades, exposing corals to higher risk of mortality. Bleached coral reefs now cover hundreds of thousands of kilometers worldwide, threatening millions of livelihoods and causing biodiversity loss that could be worth billions of dollars. A new report, A Reef Manager's Guide To Coral Bleaching, released this week by the United States’ National Oceanic and Atmospheric Administration (NOAA), the Australian Great Barrier Reef Marine Park Authority (GBRMPA) and the Swiss-based World Conservation Union (IUCN) aims to provide coral reef managers with the latest scientific information on the causes of coral bleaching and new management strategies for responding to this formidable threat. The report, which is being officially launched today in Canberra by Australia ’s Environment Minister Hon. Ian Campbell, includes contributions from over 50 international experts in coral bleaching and coral reef management. Based on experiences ranging from Palau to Kenya , the report identifies both short- and long-term management measures to help coral reefs survive mass bleaching events and recover after high coral mortality. Bleached but not dead Contrary to popular belief, bleached corals are not dead, and if the water temperature cools down soon enough they can regain their algae populations and survive the bleaching event. However, a coral’s ability to survive bleaching largely depends on the level of stress that it endures before and during such events. “Bleached reefs are essentially starving,” explains report co-author Paul Marshall from GBRMPA, “and reefs that are healthy with strong energy reserves when they start bleaching are more likely to endure the event and survive.” Stress management is the key “The management of stressors can go a long way in determining whether, or how quickly, a reef can bounce back,” says report co-author Heidi Schuttenberg, from James Cook University . “A healthy reef with few stressors may regrow coral areas in a few years, but the process typically takes at least a decade under good conditions. However, even corals in excellent condition will not be able to survive mass bleaching events if high temperatures persist,” adds Schuttenberg. The report suggests that maintaining good water quality, sustaining strong herbivorous fish populations, and protecting biological diversity are the most important strategies for helping coral reefs to recover from increasingly damaging mass bleaching events. Short-term measures, such as the restricting dredging near coral reefs in the summer, eliminating dynamite fishing and preventing boat anchoring on reefs, need to be coupled with longer-term strategies such as catchment management and marine zoning that can protect biological diversity. Furthermore, protection of healthy and resilient coral areas will become increasingly important in the future as nurseries for rebuilding damaged reefs. These areas could serve as refugia to “re-seed” damaged reefs through natural ecosystem connectivity and, in exceptional cases, could even be used for coral transplantation. Learning from experience The report presents a variety of approaches to address the plight of coral reefs around the world. Activities in Palau have concentrated on identifying resilient areas and ensuring their protection; in Florida , US, collaborative partnerships with reef users have been built during bleaching events; in Kenya , fishermen have been integrated in the monitoring programme, whilst in American Samoa climate-related research contributes to management responses and site-specific protection measures. “While there is no ‘silver bullet’ in preventing coral bleaching and dealth from rising ocean temperatures due to climate change, sharing experiences will help us find the most cost-effective ways to ensure that these vital ecosystems will remain diverse and productive for decades to come,” concludes Carl Gustaf Lundin, Head of IUCN Global Marine Programme. *** ENDS *** |
Notes to Editors
1. Contact information: In Switzerland
In Australia
2. Background information
Stages in mass coral bleaching 3. Links Full report: www.coris.noaa.gov/activities/reef_managers_guide/pdfs/reef_managers_guide.pdf IUCN Global Marine Programme: www.iucn.org/marine 4. About The World Conservation (IUCN) Created in 1948, the World Conservation Union (IUCN) brings together 81 States, 113 government agencies, 850 plus NGOs, and some 10,000 scientists and experts from 181 countries in a unique worldwide partnership. The Union ’s mission is to influence, encourage and assist societies throughout the world to conserve the integrity and diversity of nature and to ensure that any use of natural resources is equitable and ecologically sustainable. The World Conservation Union is the world's largest environmental knowl edge network and has helped over 75 countries to prepare and implement national conservation and biodiversity strategies. The Union is a multicultural, multilingual organization with 1000 staff located in 62 countries. Its headquarters are in Gland , Switzerland . Web: www.iucn.org; press iucn.org
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Areas where coral reef bleaching has been recorded. Red dots signify high mortality, yellow dots medium mortality, blue dots low mortality and green dots no mortality. Source: www.reefbase.org
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