全球珊瑚礁拉警報 2600位科學家籲立即救援

Coral reefs worldwide are being destroyed by changes in ocean temperature and chemistry faster than at any time since the last reef crisis 55 million years ago, thousands of marine scientists warned in a joint statement today.

"The future of coral reefs isn't a marine version of tree-hugging but a central problem for humanity," said Jeremy Jackson, senior scientist emeritus, Smithsonian Institution and the 2012 recipient of the Darwin Medal.

Speaking at a coral reef symposium in Cairns held only once every four years, Jackson said today, "What's good for reefs is also critically important for people and we should wake up to that fact."

At the 12th International Coral Reef Symposium, Jackson was among 2,600 of the world's top marine researchers who released an unprecedented "Consensus Statement on Climate Change and Coral Reefs."

By consensus the scientists are urging a worldwide effort to overcome growing threats to coral ecosystems and to the livelihoods of millions of people who depend on them. It calls for measures to head off the escalating damage from rising sea temperatures that cause coral bleaching, ocean acidification, overfishing and pollution from the land.

Coral bleaching occurs when high water temperatures cause corals to expel their symbiotic algae; if prolonged or severe, it can kill the corals.

Jackson told delegates that in the Caribbean Sea, 75-85 percent of the coral cover has been lost in the last 35 years. Even the Great Barrier Reef, the world's best-protected reef ecosystem, has lost half its coral cover in the past 50 years, he said.

Climate change is pushing that decline and causing increased droughts, agricultural failure and sea level rise at increasingly faster rates that implies huge problems for societies, the scientists warn.

Coral reefs provide food and livelihood for tens of millions of coastal inhabitants around the world and function as natural breakwaters for waves and storms. Reefs provide an estimated US$170 to $375 billion in goods and services globally each year.

The consensus statement says that by the end of this century, emissions of the greenhouse gas carbon dioxide at the current rate will warm sea surface temperatures by at least 2-3°C (3.6-5.4°F), raise sea-level by as much as 1.7 meters (5.7 feet), reduce ocean pH from 8.1 to less than 7.9 by dissolving additional carbon dioxide from the atmosphere in seawater, and increase storm frequency and/or intensity.

"There is a window of opportunity for the world to act on climate change - but it is closing rapidly," said Professor Terry Hughes, convener of the symposium and director of the Australian Research Council Centre of Excellence for Coral Reef Studies at James Cook University in Cairns.

"When it comes to coral reefs, prevention is better than cure," said Hughes. "If we look after the Great Barrier Reef better than we do now, it will continue to support a vibrant tourism industry into the future. Unfortunately, in Queensland, the rush to get as much fossil fuel out of the ground as quickly as possible, before the transition to alternative sources of energy occurs, has pushed environmental concerns far into the background."

"While there has been much progress in establishing marine reserves around the coastline of Australia, marine parks do not prevent pollution from the land, or lessen the impact of shipping and port developments, or reduce the emissions of greenhouse gases," said Hughes.

Stephen Palumbi, director of Stanford University's Hopkins Marine Station in California, said governments must make stronger commitments to reducing greenhouse gas emissions, and meanwhile addressing local threats, such as poor land development and unsustainable fishing practices, can help by improving reef health.

"Local action buys us time to deal with the bigger issue of climate change," Palumbi said, urging rebuilding fish populations, reducing polluted runoff and establishing more marine protected areas.

From the University of Hawaii, Robert Richmond, president of the International Society for Reef Studies, said the consensus statement is not just another document about the mounting problems facing coral reefs. Rather, it is focused on connecting the best available science with policy development and implementation through partnering with and supporting both elected officials and traditional leaders.

The five-day event at the Cairns Convention Centre is attended by more than 2,500 people from some 80 countries.

In the symposium's keynote address, the top U.S. oceans official announced a major advance in the ability to predict mass coral bleaching. The new seasonal ecological forecast system can forecast the probability of bleaching four months ahead.

Jane Lubchenco, under secretary of commerce for oceans and atmosphere and administrator of the National Oceanic and Atmospheric Administration, NOAA, said, "This advance in bleaching warning systems represents another milestone in our efforts to save the world's critically important reef systems."

NOAA's advances in satellite monitoring of the high ocean temperatures that can cause coral bleaching now provide daily five-kilometer satellite monitoring of coral bleaching thermal stress for reefs around the world. This means 100 times finer resolution, more frequent observations, and more data than the current twice-weekly 50-km global satellite coral bleaching monitoring.

The new information products use a blend of data from NOAA and international partner environmental satellites that orbit the planet combined with data from geostationary weather satellites, providing 10 to 50 times more observations each day than the older products.

"The state of reefs today should raise concerns for everyone. Reef ecosystems are globally important, and healthy reefs are the life-line for local communities," said Lubchenco. "Their continued existence is a moral imperative for the global community."

A new report released at the symposium finds that up to 90 percent of reefs in the Coral Triangle are threatened by local human activities plus climate change - much more than the global average of 60 percent.

In the six countries that make up the Coral Triangle - Indonesia, Malaysia, Papua New Guinea, the Philippines, Solomon Islands, and Timor-Leste - overfishing, watershed-based pollution, and coastal development as well as coral bleaching caused by warming ocean waters, are destroying the coral ecosystems.

The report, "Reefs at Risk Revisited in the Coral Triangle," was written by the World Resources Institute with the USAID-funded Coral Triangle Support Partnership. The partnership is a consortium of three large environmental groups WWF, The Nature Conservancy, and Conservation International that assists the six Coral Triangle governments in implementing their regional and national Coral Triangle Initiative plans of action.

The Coral Triangle contains nearly 30 percent of the world's coral reefs and more than 3,000 species of fish - twice the number found anywhere else in the world.

Spanning parts of insular Southeast Asia and the western Pacific, the Coral Triangle is recognized as the global center of marine biological diversity, with the highest coral diversity in the world - 76 percent of all coral species - as well as the highest diversity of coral reef fishes in the world - 37 percent of all species, according to the report.

More than 130 million people living in the region rely on reef ecosystems for food, employment, and tourism revenue.

"The influence of coral reefs on the most important aspects of people's lives cannot be overstated," said Katie Reytar, research associate at World Resources Institute and a lead author of the report. "The influence extends far beyond the Coral Triangle to people around the world who benefit from the fisheries, tourism, medicines, and numerous other services that reefs provide."

The six Coral Triangle countries have signed and agreed to a regional plan of action called the Coral Triangle Initiative, a collaboration that aims to protect this area, and each has developed a national plan of action aligned with the regional plan.

Within the Coral Triangle Region, the Philippines is the most highly vulnerable country because of its highly threatened reefs, very high economic dependence on reefs, and low capacity to adapt to the loss of goods and services provided by reefs, the report finds.

The authors urge a halt to destructive fishing - the use of explosives and poisons to kill or capture fish, a common practice across much of the Coral Triangle Region, particularly in East Malaysia, the Philippines, and Indonesia, threatening nearly 60 percent of the region's reefs.

When conserved, coral reefs can recover, and the authors agree that healthy reefs are more likely to survive the negative effects of climate change, such as coral bleaching or slower coral growth due to increased ocean acidity. They, too, say that tackling the local threats first will buy reefs time until the global community can reduce greenhouse gas emissions.