In a stunning example of the natural world’s remarkable ability to bounce back from ecological decline, the coral reefs surrounding Little Cayman Island in the Caribbean Sea—all but written off as dead by some marine scientists a decade ago—are rapidly regaining their health.
Back to Pre-Bleaching Levels
Bleaching, blamed by global warming activists on warmer ocean water, and the spread of infectious disease, took a heavy toll on the reefs around the turn of the century. From 1999 to 2004, live coral cover declined by more than 40 percent. But a 13-year study conducted by the University of Florida and Caribbean researchers and released in November 2013 found the amount of live coral on the reefs, the density of young colonies critical to the reefs’ future health, and the overall size of corals have returned to 1999 levels.
The study was published in November in the peer-reviewed online periodical Public Library of Science.
An Encouraging Resilience
Chuck Jacoby, a University of Florida researcher who participated in the study, pointed out much of the reef surrounding Little Cayman Island is protected, limiting damage from fishing, anchoring, and other human activities.
“Nevertheless, all coral reefs, even those that are well protected, suffer damage,” Jacoby said in a University of Florida press release. “Little Cayman is an example of what can happen, because it is essentially free from local stresses due to its isolation, small human population, and generally healthy ecology.”
Located approximately 60 miles northeast of Grand Cayman, Little Cayman is about 10 miles long and has an average width of one mile. It is home to approximately 170 residents.
“There’s a debate over how resilient coral reefs are,” said Tom Frazer, a professor of aquatic ecology and director of the University of Florida’s School of Natural Resources and Environment, in the same press release. “Some say it’s a lost cause. We believe there’s value in making sure coral reefs don’t die.”
Known for their vibrant colors and the colonies of tiny marine animals they house, coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs occupy less than 0.01 percent of the marine environment, but they harbor up to 25 percent of the different species of marine organisms. They yield about 25 percent of the fish caught in developing nations and generate up to 30 percent of the export earnings of countries that promote reef-related tourism, the study reports.
Over the past couple of decades, ecological deterioration of coral reefs, including those surrounding Little Cayman Island, has been attributed by some scientists and environmental activists to manmade global warming. However, the rebound of the reefs surrounding Little Cayman Island despite rising atmospheric carbon dioxide (CO2) levels casts doubt on the influence of greenhouse-gas-induced climate change on coral reefs.
No Warming Harm Seen
“My impression of concerns raised by climate-change alarmists involving purported adverse effects on coral reefs from warming oceans and rising dissolved CO2 concentrations in the seawater surrounding coral reefs is that the claims are naturally inconsistent and greatly overblown. Others factors more likely account for instances of dying or sick reefs,” said William D. Balgord, Ph. D., a geochemist and president of Middleton, Wis.-based Environmental & Resources Technologies, Inc.
“The Great Barrier Reef has persisted throughout geological ages,” including periods of fluctuating temperatures and atmospheric carbon dioxide levels, Balgord observed.
Balgord noted studies show the recent warming seems to be beneficial to coral.
“Recent research cited by Craig Idso of the Center for the Study of Carbon Dioxide and Global Change also shows that coral are robust with regard to moderate thermal excursions and to elevated carbon dioxide in surrounding seawater,” he said.
“Coral colonies are composed of individual sessile animals that enclose symbiotic algae within each individual cell,” Balgord explained. “The algae photosynthesize the CO2 produced by the animal’s metabolism, thus producing food, and maintain a nearly constant internal pH highly favorable to and protective of the coral—a micro-environment. That the reef cited in the University of Florida study is rejuvenating should be welcomed by all.”
Bonner R. Cohen, Ph. D., ([email protected]) is a senior fellow at the National Center for Public Policy Research.
“A Positive Trajectory for Corals at Little Cayman Island,” PLOS One, October 9, 2013, http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0075432