Coral reefs have a lot of reasons to be stressed out. Climate change, pollution, ultra-violet rays, coastal run-off and rough weather all take their toll on reefs. These threats trickle down to the many marine species that depend on reefs for homes, food, and breeding grounds.

Earlier this year, WCS researchers developed a stress test (see A Stress Test for Corals on Edge) to ascertain just how well coral reefs are handling the changing conditions within their environment. This helps the scientists evaluate which reefs have the best chance at survival over the next 50 years or so, and therefore where to best direct conservation efforts.

Ina recent study published in the journal PloS One, WCS researchers and partners mapped out the world’s reefs according to how much stress the corals endure, placing priority on those with a high level of biodiversity and limited exposure to stressful conditions.

“Coral reefs around the globe are under pressure from a variety of factors such as higher temperatures, sedimentation, and human-related activities such as fishing and coastal development,” said Joseph Maina, a WCS conservationist and the study’s lead author. “The key to effectively identifying where conservation efforts are most likely to succeed is finding reefs where high biodiversity and low stress intersect.”

The map also takes into account conditions that could help make reefs resilient to stress, such as temperature variability and tidal dynamics. Management strategies that could further protect reefs might include restricting fishing in some areas, reducing agricultural run-off, and replanting forests along coastlines to reduce sediments from flowing offshore.

“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 WCS’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.”

To learn where some reef systems fall on the coral stress map, see the press release.