Coral reefs are naturally resilient ecosystems, adapted to recover from battering storms that frequently strike the tropical areas where they occur. However, reefs today face many more threats than the occasional hurricane—intensifying global stresses like climate change and ocean acidification are accompanied by increasing local threats from coastal development, destructive fishing practices, careless tourism, and pollution.
It has been shown that both local and global stresses can significantly degrade coral reefs. But how do these different pressures interact? Could acclimatization to a stressful environment actually increase corals’ ability to withstand future stress? A recent paper published by the Public Library of Science (PLoS ONE) provides evidence that such wishful thinking is mistaken.
Rising ocean temperatures can induce coral bleaching, a phenomenon in which corals expel the symbiotic algae that provide an essential portion of their nutrition. Corals may recover their algae and survive if conditions become favorable again, but the stress can reduce their growth rates. Based on studies of coral growth in four locations on the Meso-american Reef around a mass bleaching event in 1998, the conclusion of the recent PLoS ONE paper is evident from its title: “Local Stressors Reduce Coral Resilience to Bleaching.” The study found that coral growth rates at sites that were relatively free from local stressors recovered in two to three years, while growth rates in sites with higher local stressors remained suppressed for at least eight years.
Studies of coral reefs in locations as diverse as Australia, the Coral Triangle, and Bonaire all present similar results: corals are most able to recover from large-scale threats like rising ocean temperatures, water quality decline, and storm damage when they are healthy to begin with. Building reef resiliency by reducing local stressors is the best strategy we have to help them withstand the global threats that will take longer to curtail and are already taking effect.
With data from the National Oceanic and Atmospheric Administration showing record high ocean temperatures this summer, and a new study in the journal Nature indicating that the past decade has seen more frequent hurricanes than any time in the past 1,000 years, it is clear that we must act quickly to bolster reef health and build robustness.
Experts from around the world are advocating networks of effectively managed marine protected areas, coupled with widespread education, poverty alleviation, and alternative livelihood creation, as essential components of a global approach to saving coral reefs.
Although reducing carbon dioxide emissions will be necessary to limit the detrimental impacts of climate change and ocean acidification, the long-term survival of coral reefs depends on our action now to alleviate local pressures and support healthy, resilient reef ecosystems.
*Adapted from the Coral Reef Alliance
The Marino Ballena National Park and Cano Island Biological Reserve are home to some of Costa Rica’s most beautiful coral reefs. Locals and visitors alike can enjoy some of the best Costa Rica Snorkel and Diving Tours. The importance of maintaining our beautiful Coral Reefs cannot be understated.
Coral Reefs are naturally resilient ecosystems, however, our coral reefs today face many threats such as, intensifying global stresses like climate change and ocean acidification. These threats are are accompanied by increasing local threats from coastal development, destructive fishing practices, careless tourism, and pollution.
It has been shown that both local and global stresses can significantly degrade coral reefs. Studies based on coral growth have found that coral growth rates at sites that are relatively free from local stressors recovered in two to three years, while growth rates in sites with higher local stressors remained suppressed for at least eight years. Studies of coral reefs in locations as diverse as Australia, the Coral Triangle, and Bonaire all present similar results: corals are most able to recover from large-scale threats like rising ocean temperatures, water quality decline, and storm damage when they are healthy to begin with.
Building reef resiliency by reducing local stressors is the best strategy we have to help our coral reefs withstand the global threats that are already taking effect. It is clear that we must act quickly to bolster reef health and build robustness. Experts from around the world are advocating networks of effectively managed marine protected areas, coupled with widespread education, poverty alleviation, and alternative livelihood creation, as essential components of a global approach to saving coral reefs.
The long-term survival of coral reefs depends on our action now to alleviate local pressures and support healthy, resilient reef ecosystems.
*Adapted from the Coral Current 2009 Autumn Edition – Coral Reef Alliance
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