Sunday, August 14, 2011

Coral Reef Stress Factors: scientists develop world map for better marine management

In March, I wrote of a coral reef stress test developed by scientists from the Wildlife Conservation Society. The stress test was a model based on several environmental factors that impact the viability of a coral reef's ability to survive. Some of the key factors included in the test model were water temperature, biodiversity, and tidal movement. The idea behind the stress test was to help enable marine management organizations to better determine which reef areas had a higher rate of survivability to as best to manage human activities that might exacerbate the identified stress factors.

The Wildlife Conservation Society has continued working with their stress test model and in a recent issue of PLoS One, have presented a map of the world's coral reef regions with the stress test applied. The purpose of the map is to identify the types of stress placed upon coral reef regions so that, again, marine management organizations can compare human activities with the kinds of stress already taking place naturally and in so doing decide the most appropriate course of coral reef management to ensure its survival.

The map basically identifies two groups: those with high radiation stress (sea surface temperature, ultra-violet radiation, and minimal wind weather patterns) combined with few stress-reducing factors such as temperature variability and tidal movements - call this a high stress group - and a second group with less intense stress factors and a greater level of stress-reducing ones - call this the moderate group.

For marine management, these stress factors - while not necessarily fatal for any coral region when the reef is left in a pristine, undisturbed natural state - are not something that can be controlled, except on a global level that deals with the larger issue of climate change. However, when you add in man-made impacts like overfishing, pollution, and coastal development, then what the region is able to withstand can be exceeded, and this is where marine management and marine protected areas can then have the greatest impact.

In the high stress group, the researchers included coral reef regions in Southeast Asia, Micronesia, Eastern Pacific, Central Indian Ocean, Middle East, and Western Australia. The second, more moderate stress group included the Caribbean, Great Barrier Reef, Central Pacific, Polynesia, and the Western Indian Ocean.

“When radiation stress and high fishing are combined, the reefs have little chance of surviving climate change disturbances because they both work against the survival of corals that are the foundation of the coral reef ecosystem,” said Dr. Tim McClanahan, Wildlife Conservation Society Senior Conservationist and head of the society’s coral reef research and conservation program.

“The study provides marine park and ecosystem managers with a plan for spatially managing the effectiveness of conservation and sustainability,” said Dr. Caleb McClennen, Director of the society’s Marine Program. “The information will help formulate more effective strategies to protect corals from climate change and lead to improved management of reef systems globally.”

Coral reefs are critically important but very fragile marine ecosystems and have already been seriously affected by man-made activities. The more tools we have at our disposal to ascertain the survivability of a particular region the better management decisions that can be made before it is too late.

Map courtesy of the Wildlife Conservation Society.

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