New research published Wednesday warns of dire consequences for humans in low-lying areas of the world with large coral reefs, including the U.S. Virgin Islands.
The research, published in the scientific journal PLOS, was written “to understand where the effects of climate change and ocean acidification would affect the most people,” said Linwood Pendleton, a senior scholar at Duke University’s Nicholas Institute for Environmental Policy Solutions who is a lead author on the report.
The report details areas around the world that face threat from how “increasing levels of carbon dioxide in the atmosphere put shallow, warm-water coral reef ecosystems, and the people who depend upon them, at risk,” he said.
“We chose climate change and ocean acidification because these two factors are beyond the control of most coral reef dependent communities,” Pendleton said. “Of course, a lot of people depend on coral reefs in the USVI. They depend on tourism; on reef fish for food and reef fishing for jobs; and people who live near the sea depend on corals to break waves, especially waves and storm surge caused by hurricanes.
“The USVI face a moderately high threat from increasing sea temperature, which can cause bleaching,” Pendleton said Thursday from Paris. “The threat from ocean acidification, for the USVI, is well below the threat faced by most coral areas. So, the combined threats of bleaching and ocean acidification are relatively small compared to coral reef areas in Australia and Southeast Asia.”
The report said 34,003 people are at risk from increased waves and storm surge.
“Coral reef ecosystems create natural barriers that protect shorelines from storm surge and erosion — defending villages, businesses, and coastal residents,” the report states.
Pendleton said the degradation of the reefs increases risk to people living at certain low elevations. “The coral reef crest breaks waves. When corals die, fish and algae can begin to weaken corals. Storms and waves can break these corals. When this happens, the reef crest disappears and no longer breaks waves.”
The risk is for “people that live at low elevations — less than 30 feet above sea level — and within 3 kilometers, slightly less than 2 miles, of a coral reef,” he said.
Pendleton said that increased bleaching means reefs don’t have a chance to rebuild. “When corals are damaged by bleaching they can die. Hurricanes can also kill corals. Normally, corals have time between bleaching events and hurricanes to regrow. The problem comes when bleaching happens so often that the corals cannot regrow. Ocean acidification makes it even harder for corals to grow back because even small changes in the pH of the water can reduce growth rate and the reproductive success of coral. Even worse, when warmer oceans combine with ocean acidification, the effects on growth and reproduction are more than twice as bad for each factor alone,” he said.
Pendleton said research shows limits on fishing can help extend the life of a coral fishery.
“Corals have proven reasonably resistant to both warmer temperatures and ocean acidification, when other environmental stresses are low. Overfishing and damaging fishing practices — for instance dynamite, cyanide, spearfishing that causes coral breakage — put extra stress on the reef ecosystem,” he said. “If properly managed, low-impact fishing can be accommodated, even when climate change and ocean acidification is a serious threat.”
Pendleton also said the threat can be mitigated.
“Damage to coral reefs is reversible. We do not know yet if coral reefs will be able to evolve or adapt to rising sea-surface temperature, but we do know that coral reefs that currently have well-managed fisheries and low levels of pollution are healthier, even in the face of warmer waters and waters that have experienced ocean acidification.”
He said the territory largely controls its coral destiny.
“Unlike other places, the most serious threats to coral reefs in the USVI are likely to be largely homegrown,” Pendleton said. “The fate of USVI coral reefs are largely in your hands. Other places are not so fortunate.”
EPA spokesman John Martin said Thursday that an EPA initiative is intended to address the issues raised in Pendleton’s research.
“The EPA’s Caribbean Coral Reef Protection Group continues to work with our fellow governmental agencies, including The Virgin Islands Department of Planning and Natural Resources and other federal agencies, to coordinate efforts to protect coral reefs. Our focus has been to address overfishing, sediment runoff, pollution, and other stresses that can be controlled locally,” Martin said.
“In addition, the EPA continues to develop regulatory initiatives to reduce greenhouse gas emissions and increase efficiency, such as the Clean Power Plan, which will put the nation on track to cut harmful pollution from the power sector by 32 percent below 2005 levels,” he said.