Global warming and human impacts combine destructive forces on coral reefs

provided by University of Queensland


cientists from around the world have issued a call for humanity to reduce the damage it is doing to coral reefs. Reefs are the foundations of tropical marine ecosystems and provide essential “natural services” to island communities, such as food and protection from erosive wave action.

    Meeting in Indonesia heart of the world's marine biological diversity 1,500 scientists from more than 50 countries discussed breakthroughs in understanding the health of coral reefs and addressed the serious degradation that coral reefs are suffering at the hands of human beings. A nine-member scientific panel representing the majority of scientists at the Ninth International Coral Reef Symposium (ICRS) in Bali and including some of the world's preeminent marine biologists concluded that, barring major reforms, “coral reefs face a bleak future.”

    The panel called upon the nations of the world to reduce their emissions of heat-trapping greenhouse gases. Panel representative Yossi Loya, professor at Tel Aviv University and winner of the International Society for Reef Studies' 2000 Darwin Award for lifetime contribution to coral reef science, declared, “As a coral reef society, we add our voice to the growing international concern on the issue of global climate change, and call for an effective reduction in greenhouse emissions over the next decade.”

    The overwhelming majority of scientists at the Bali conference agreed that climate change is having a significant impact on the world's coral reefs. High water temperatures such as the record sea surface temperatures reached throughout the tropics during the 1997-98 El Niño Southern Oscillation event cause coral to “bleach” or expel the algae they live symbiotically with. Bleaching starves and often kills corals. It also makes them more susceptible to marine diseases. Elevated concentrations of carbon dioxide, the main cause of global warming, also directly harm corals, whose skeletal growth declines in carbon dioxide-enriched water.

    Richard Aronson, senior marine scientist at Alabama's Dauphin Island Marine Lab, made a statement at Friday's closing press conference: “There is clearly cause for grave concern for the future of coral reefs if present climate trends continue.”

Fishing practices criticized

    Other scientific panels at the conference emphasized the need to address the many other threats facing coral reefs, among them the destructive fishing practices that are the main threat to coral reefs in Southeast Asia, overfishing, land-based pollution, and introduced species and diseases.

    Scientists declared an absolute need for strict enforcement measures against destructive fishing. “Carrot” programs, such as alternative income schemes, are highly prone to failure if not combined with the “stick” of strong enforcement. Economic analysis demonstrates that NOT enforcing blast fishing regulations is now costing Indonesia over $200 million per year.

    In addition to the call to action, scientists presented more than 1,500 papers detailing the latest science on these rich but endangered ecosystems. Perhaps the most comprehensive of the reports released at the conference was the Status of Coral Reefs of the World 2000 report of the Global Coral Reef Monitoring Network, which found that one-fourth of the world's reefs had been eliminated and another third were severely threatened. Those findings set the context for the “emergency room science” discussed at the meeting. Most of the scientific papers on topics as varied as shrimp genetics and aquarium trade economics had conservation implications or focus.

    Though coral reefs in many parts of the world are in critical condition, improved management can help preserve coral reefs, the richest ecosystems in the underwater majority of planet Earth. The symposium sessions reported many successful examples of coral reef conservation. For example, no-fishing protected areas have allowed fish populations as well as fishing in adjacent areas to rebound dramatically in fewer than five years.

    Other symposium studies helped shed light on the spread of diseases in coral reef ecosystems, suggested possible breakthroughs in helping coral reef ecosystems survive coral bleaching, and presented ideas for helping coral reef managers prevent degradation by more local forces, such as blast and cyanide fishing. Surprising findings include the partial but rapid recovery of some reefs from the 1997-98 El Niño, in part due to the recently discovered diversity of algae that can live even within one coral colony.

    The scientists agreed that both local, immediate threats, like dynamite fishing, and global threats, like climate change, must be addressed simultaneously. As Ove Hoegh-Guldberg, director of the Centre for Marine Studies at the University of Queensland explained, “If you're being charged by a rhino at 20 meters, and 100 meters away there's an enraged bull elephant, it pays to concentrate on both of those animals.”

    Contacts: Ove Hoegh-Goldberg, University of Queensland, 61 7 3365 4333,; Yossi Loya, Tel Aviv University, 972 3 640 7683, yosiloyapost; Mark Erdmann, Manado National Park,, HP 0811 433857; Lida Pet-Soede, WWF Indonesia;; Phone +62 361 731105; HP 0812 3805731.