With smart action, hope isn’t lost for coral reefs

A diver explores a coral reef that has experienced bleaching. (Credit: The Ocean Agency)

Management that takes evolution and adaptation into account can help rescue coral reefs from the effects of climate change, according to a new study.

Importantly, the results show that by making smart decisions to protect reefs today, conservation managers can generate the conditions that can help corals adapt to rising temperatures.

“It is well documented that climate change is causing corals to die off at an unprecedented rate, but our study provides tools that offer promise for their survival,” says coauthor Madhavi Colton, program director at the nonprofit Coral Reef Alliance. “Our results show that when evolution is enabled, conservation efforts can help corals adapt to rising temperatures.”

A healthy reef in Indonesia teems with life
A healthy reef in Indonesia teems with life. (Credit: Michael Webster/Coral Reef Alliance)

Saving coral reefs from climate change

Contrary to approaches that are popular today, such as focusing protection on reefs in cooler water, the study shows that protecting diverse reef habitat types across a spectrum of ocean conditions is key to helping corals adapt to climate change.

“We found that a diversity of reef types provides the variety that evolution depends on,” says coauthor Malin Pinsky, an associate professor at Rutgers University. “Hot sites are important sources of heat-tolerant corals, while cold sites and those in between can become important future habitats. Together, a diversity of reef types act as stepping stones that give corals the best chance for adapting and moving as climate changes.”

A green sea turtle passes through a cleaning station in Hawaii
A green sea turtle passes through a cleaning station in Hawaii, where a Coral Reef Alliance initiative is working with local partners to improve water quality throughout the state. (Credit: Michael Webster/Coral Reef Alliance)

Key to successful evolution is management that improves local conditions for reefs by effectively reducing local stressors, such as overfishing and water pollution. However, the authors caution that not all management strategies are created equal.

“We used mathematical models to test the effects of management choices on coral reef outlooks,” says lead author Tim Walsworth, a postdoctoral researcher at the School of Aquatic and Fishery Sciences at the University of Washington.

A coral reef in Roatan, Honduras
A coral reef in Roatan, Honduras, is reflected in the surface of the water above. (Credit: Michael Webster/Coral Reef Alliance)

“We found that corals in well-managed areas act as a source of baby corals in the future, essentially rescuing reefs after the climate stabilizes. Without both evolution and management, the corals in our model were unable to survive rising temperatures.”

Time to act

Coral reefs are one of the most diverse ecosystems on the planet and support the livelihoods of over 500 million people. Globally, they are estimated to be worth $375 billion per year.

The study shows that managing reefs to facilitate evolution today and in the future can enhance their prospects for long-term survival. This means creating managed area networks that contain a diversity of coral types and habitats and effectively reduce local stressors.

“This study shows that we know enough of the science to act—and with the effects of climate change only increasing, we have little time to waste,” Colton says.

The study appears in Nature Climate Change.

The study is the result of a collaborative research program Colton and Michael Webster of the Coral Reef Alliance launched. Additional coauthors and project collaborators came from the University of Washington, Stanford University, and the University of Queensland. Funding for the research came from the Gordon and Betty Moore Foundation.

Source: Coral Reef Alliance via University of Washington