Marine reserves, while effective at protecting coral reefs against local issues, are not protecting them against global issues such as climate change, according to Associate Professor John Bruno from the University of North Carolina.
Professor Bruno presented his findings to the Ecological Society of Australia’s annual conference at the University of Sydney.
18 Years of Data
In a speech entitled Climate change and coral reef resilience: are we expecting too much from marine reserves?, professor Bruno and former graduate student Elizabeth Selig compared 18 years worth of data collected from 8,540 coral reefs in the Indian, Caribbean and Pacific regions between 1987 and 2005.
They found that, while marine reserves are important for protecting fish populations, maintaining coral reef food webs and protecting against anchor damage, they are unlikely to prevent coral loss due to increased sea temperatures.
“We found that while coral loss was reduced in marine reserves, the rate of coral decline with warmer temperatures was just the same in marine reserves as in highly fished areas,” professor Bruno explained.
Bruno believes that regional and global issues are the largest threats to marine reserves.
“The biggest stresses put on coral reefs are ocean warming and disease outbreaks,” he says. “These stresses are regional and global in scale and local protection through marine reserves is unlikely to help these reefs resist such changes.”
Older Reserves Are More Resilient
Although marine reserves don’t directly guard against regional and global issues, professor Bruno did find that older reserves are in a better position to protect against coral loss than younger reserves.
“We don’t know the reason for this result, although we can speculate that it could be due to longer-term marine reserves being better managed or established,” he says.
Bruno believes that we need to think long term and establish marine reserves that can protect coral reefs from unknown future threats.
“Restoring and protecting corals from climate change requires urgent implementation of regional and global strategies to deal with the root causes of climate change, including reducing carbon emissions.”