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 on Monday, July 9 from Cairns, Australia.
The Great Barrier Reef coral Acropora tenuis spawning. (Photo courtesy A. Hayward and A. Negri, Australian Institute of Marine Science)
“The future of coral reefs isn’t a marine version of tree-hugging but a central problem for humanity,” said Jeremy Jackson, a senior scientist emeritus at the Smithsonian Tropical Research Institute in Panama and recipient of the 2012 Darwin Medal.
Speaking at a coral reef symposium in Cairns held only once every four years, Jackson said, “What’s good for reefs is also critically important for people and we should wake up to that fact.”
Jackson was among 2,600 of the world’s top marine researchers at the 12th International Coral Reef Symposium who released an unprecedented “Consensus Statement on Climate Change and Coral Reefs.”
Image right: A coral specimen from Guam (Smithsonian Tropical Research Institute/NOAA image).
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 $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 Terry Hughes, director of the Australian Research Council Centre of Excellence for Coral Reef Studies at James Cook University in Cairns. –Source: Environment News Service
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