Some ocean ecosystems are bouncing back from climate change stress. What makes them special?

As 2016 closed on another record year of rising temperatures, scientists have been searching for signs of ecosystem resilience in an ocean beset by coral bleaching and increasing ocean acidification. Now, they’ve found a reason to be optimistic.

Several factors may promote ecosystem recovery and allow the habitats to persist in the face of climate change, according to a study published online February 1 in the journal BioScience.

“We found a remarkable percentage of experts who had witnessed resilience across diverse global locations and ecosystems,” said lead author Dr. Jennifer O’Leary, California Sea Grant Extension Specialist based at California State Polytechnic University (Cal Poly) in San Luis Obispo and postdoctoral researcher at Stanford University’s Hopkins Marine Station at the time of the study. “Coastal ecosystems may still hold great potential to endure, and there are steps we can take to help buffer the impacts.”

Ocean Optimism

The study found that more than 80 percent of coastal ecosystem scientists surveyed say they have observed instances of habitats resisting or recovering from climate change impacts. The study’s authors designed an expert survey to look at how common resilience is in marine nearshore habitat. Survey respondents on average had 25 years of experience in studying coastal habitats, and provided insight on the factors that promote and inhibit resilience.

Factors such as remaining biogenic habitat, recruitment and connectivity, physical setting, and management of local-scale stressors were identified as enhancing ecosystem resilience.

O’Leary said the results are a cause for “ocean optimism” and pinpoint the best management strategies to help ecosystems rebound from impacts like heavy storms and environmental disturbances. For example, after the 1997–98 El Niño, which had strong waves and high temperatures, the giant kelp forests in California rebounded as a result of high recruitment.

Buffering Global Impacts, Locally

The authors suggest that local- to regional-scale management can help buffer global climatic impacts. In California, that means the network of marine protected areas (MPAs) may help increase coastal resilience by protecting the existing habitat and promoting better recruitment.

For habitats that are already hard hit—such as the massive seagrass loss in Morro Bay—hope remains that the system may recover as not all eelgrass was lost. The Morro Bay National Estuary Program, working jointly with Dr. O’Leary and Cal Poly, has identified new eelgrass plots emerging, a sign of potential recovery.

“There is a high amount of resilience in nearshore ecosystems which is often unreported in scientific literature. Resilience occurs around the world,” said O’Leary. “By understanding what we can do to increase future resilience, we can protect better habitats from disturbances.”