The Ocean's Top 10 Coral Reef Hotspots Identified For First Time
Study Sounds Alarm for Extinctions of Marine Species
The world's top 10 coral reef hotspots, rich in marine species found only in small areas and therefore highly vulnerable to extinction, are identified for the first time in a study by the Center for Applied Biodiversity Science (CABS) at Conservation International and published in the Feb. 15 issue of Science magazine.
The paper contradicts a long-held contention that marine species are unlikely to become extinct as a consequence of human activities because of their vast geographic ranges in the oceans. CABS conducted the study in order to identify priority areas for coral reef conservation.
"We know that unless we take action right away, marine species will start going extinct, because you lose biodiversity as a consequence of habitat destruction. This study can help us create an urgently needed strategy that targets the places where biodiversity is bleeding away most rapidly," said Dr. Callum Roberts, of the University of York, lead author of the report.
The 10 coral reef hotspots, ranked according to the degree of threat, are:
These 10 hotspots account for a tiny 0.017 percent of the oceans, but claim 34 percent of restricted-range coral reef species. The study identified a total of 18 areas with the greatest concentrations of species found nowhere else, and determined the hotspots category based on threats.
"The oceans have long been considered limitless places where we have little impact on species' survival. But the richest of the shallow tropical marine habitats are at risk of disappearing at an incredibly fast rate. This study is further proof that we need to dramatically increase conservation efforts at sea," said Dr. Sylvia Earle, Executive Director for Marine Conservation with Conservation International (CI).
Eight of the 10 coral reef hotspots are adjacent to a terrestrial hotspot, those regions of the world that harbor the highest concentrations of species on land and are also at the greatest risk.
"The phenomenal overlap of the coral reef hotspots and the terrestrial hotspots shows that we're in the right places for lizards and lizardfish alike," said report co-author Tim Werner, Senior Director with CI Marine Conservation. "The reward for pursuing an integrated conservation strategy for land and sea will be high returns on conservation investments in these regions."
Activities destroying habitat in the terrestrial hotspots are also contributing to coral reef destruction. Some 58 percent of the world's reefs are reported as threatened by human activities.
Agriculture, deforestation and development resulting in large quantities of sediment, nutrients and other pollutants going into coastal wasters, as well as intense fishing and climate change, are listed as the leading causes of reef ecosystem destruction.
A quarter of the world's coral reefs have already been destroyed or severely degraded through global warming, according to the paper. Reef degradation in these hotspots could cost some of the world's poorest people an important source of nutrition, and in many cases their livelihoods. In the Philippines, for example, people derive some 70 percent of their animal protein from seafood.
The study mapped the geographic ranges of a total of 3,235 species, including reef fish, corals, snails and lobsters, four separate animal groups that all require healthy reef environments in order to survive.
The creation of marine reserves off limits to fishing is one of the steps that should be taken immediately, Roberts said. About six percent of the world's land is in parks. But at sea, less than one-half of one percent is in any kind of protected area.
"In the seas, conservation is proven to be economically beneficial. Marine reserve protection will pay for itself if designed properly. In marine reserves, fish live longer, grow larger and can replenish surrounding fisheries. Five years after setting up a network of marine reserves around the Caribbean island of St. Lucia, for instance, fish catches had nearly doubled," Roberts said.
In addition to the correlation with terrestrial biodiversity hotspots, the paper notes that tropical reef ecosystems include "wilderness" areas, which remain far less impacted by people, are rich in species, and relative to degraded areas, still contain abundant populations of reef species such as sharks that quickly disappear from overexploited reefs. These include places such as New Guinea, a terrestrial tropical wilderness area that also has coral reefs in near pristine condition relative to other parts of the world. The study recommends that conservation efforts extend to both the coral reef hotspots and these "wilderness" areas.
For more information, or to contact Conservation International, see their website at: www.conservation.org
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