KEY LARGO, Florida (30 Nov 2008) — The last, largest stands of ancient elkhorn coral survive in shallow waters off North Key Largo, where rough seas sometimes expose thick golden branches reaching toward the sunlit surface. Forty years ago, elkhorn grew in dense forests that would cover parking lots. Now, the biggest clump would barely fill one space. In another 40 years, elkhorn could disappear altogether -- along with just about every other hard coral forming South Florida's once-vibrant barrier reefs. Federal regulators last week designated a 1,329-square-mile strip of sea bottom stretching from southern Palm Beach County to the Dry Tortugas as critical habitat for elkhorn and staghorn corals, two species that have long formed the foundation of barrier reefs off Florida and in the Caribbean. But a new report by the Environmental Defense Fund and co-authored by two University of Miami scientists argues localized protections will do little to address the biggest threat to reefs. Global warming is not only accelerating problems that already have sickened and shrunken coral reefs, it has created a new, potentially more lethal threat: Increasingly acidic ocean waters that can reduce living coral to dead rubble. The report, ''Corals and Climate Change: Florida's Natural Treasures at Risk,'' concludes that 5,000-year-old reefs, which support an array of marine life, will be among the first ecosystems to collapse if greenhouse gas levels continue to rise in the atmosphere. ''All of the forecasts show that at the rate we're going that somewhere at the middle or the end of the century, it's going to be very challenging for corals,'' said Harold Wanless, UM's chairman of geological sciences. Wanless, who has studied rising sea levels in South Florida for decades, is one of the report's six co-authors, along with department colleague James Klaus, a UM assistant professor. The others: Terry Gibson, longtime environmental journalist in Florida; Patricia Foster-Turley, wildlife biologist based in Fernandina Beach; and Karen Florini and Thomas Olson, attorneys with the Environmental Defense Fund. GREENHOUSE EMISSIONS Jerry Karnas, director of Environmental Defense's Florida climate project, said the report bolsters the case for dramatic state, federal and international steps to reduce greenhouse emissions -- particularly of carbon dioxide -- largely produced by cars and power plants burning fossil fuels. ''We're ground zero for impacts,'' said Karnas, who served on Gov. Charlie Crist's climate action team. The report doesn't break new ground but it does compile the latest studies of reef decline, threats and ripple effects on both the environment and economy. It estimates the loss of reefs, which are a magnet for tourists, divers and anglers, would cost 70,000 jobs and $5.5 billion in sales annually in five southeast counties alone: Miami-Dade, Broward, Monroe, Palm Beach and Martin. Staghorn and elkhorn corals, the first coral species to be listed as threatened under the federal Endangered Species Act in May 2006, came under new federal protection issued last week. Once the major reef builders in South Florida's shallow barrier reefs, the large corals, whose stalks resemble the horns of their animal namesakes, have declined by as much as 97 percent off the Florida Keys and the Caribbean. Scattered colonies also have been found off Broward and Palm Beach counties. Last month, the National Marine Fisheries Service issued new regulations focused on direct human damage from anchoring, groundings, fishing, pollution and collection -- similar to protections already in place in the Florida Keys National Marine Keys sanctuary. The agency followed up last week by designating waters less than 30 feet deep off the Southeast coast -- from Boynton Beach to the Dry Tortugas -- as critical habitat for the corals. It's only about a third the size originally proposed, eliminating sections of Florida Bay and northern waters where the agency ruled the corals have not been historically found. Environmentalists and many scientists argue the new protections don't address broader and increasing assaults on reefs, including assorted diseases and bouts of coral bleaching -- a whitening that can weaken corals. Bleaching, linked to warming ocean temperatures, is just one of threat posed by climate change. Another one call ocean ''acidification'' is a potentially far more damaging, said Chris Langdon, a professor at UM's Rosenstiel School of Marine & Atmospheric Science. A NEW STRESSOR ''This is a new stressor over and on top of everything you have heard about already,'' said Langdon, whose is among several UM scientists who have chronicled rising acidity in oceans. | | Damaged elkhorn coral. Florida's hard corals are losing the battle against global warming, ocean acidification, coastal development and pollution. Simply put, oceans absorb much of the atmosphere's excess carbon dioxide, where it dissolves. The resulting rise in the acidity of sea water -- it's jumped 30 percent over the last century -- can cripple corals, which are particularly sensitive to changes in temperature, light and chemistry. It hinders polyps -- the tiny living animals inside coral -- from processing calcium, an essential component to building the hard coral skeleton that shelter them and build reefs. As ocean acidity increases, Langdon said, the rates of coral growth and reproduction slow and the swaths of the ocean where they can survive shrink. The coral itself also becomes thinner, more brittle and vulnerable to disease, hurricanes, human damage and natural parasites. Wanless likened what can happened to weakened or damaged reefs to ''termites going at a complex of wood.'' Corals can literally dissolve into calcified sediment. If carbon dioxide emissions aren't curtailed, the threats add up to what Langdon called a ''perfect storm'' that could destroy much of the world's reefs -- perhaps within four to five decades. Wanless considers a four- to six-foot rise in sea level almost unavoidable over the next 50 to 100 years, an increase that would inundate the Everglades and hundreds of millions worth of coastal real estate. But he believes there is still time to prevent far more catastrophic damage -- if people and policymakers will only pay closer attention to what already is happening just a few miles offshore. ''People just can't imagine the world changing as it may this century,'' he said. CORAL REEF FACTS | Coral Reefs Are Valuable Coral reefs comprise only 0.2% of the ocean floor, yet they are home to more than 25% of all marine life. An estimated one million species of plants and animals depend on coral reefs.Annually, reefs generate $375 billion in economic value through tourism, fishing, and other industries.Coral reefs account for 25% of the global fish catch, helping feed one billion people in Asia alone.Chemical compounds found only in coral reefs help produce numerous medicines for treatment of diseases including cancer and AIDS, and research in this area is in its infancy.Reefs protect human populations along coastlines from wave and storm damage by serving as buffers between oceans and near shore communities.A recent national poll indicated that 78% of Americans support designating portions of coral reefs as protected areas.Reefs Are Threatened At Unprecedented Rates 11% of the world's reefs have been destroyed and another 16% have been significantly damaged.Nearly 60% of the world's remaining reefs are at significant risk of being lost in the next 30 years. In Southeast Asia alone-considered to be the most biologically diverse in the world-88% of the region's reefs are threatened.Recent episodes of coral bleaching-a phenomenon that leaves coral reefs highly susceptible to mortality-indicate that reefs once thought to be safe and pristine are also at risk of destruction.Major Causes Of Coral Reef Decline Coastal development and increased sedimentationDestructive fishing practices including such as cyanide and dynamite fishingGlobal warming and coral bleachingSewage and chemical pollutionCollection of corals and reef animals for souvenirs, jewelry and aquariumsCareless tourism |
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