Cal Poly Study Reveals Resilience of Coastal Ecosystems

Contact: Jennifer O’Leary
805-756- 5389; jkoleary@calpoly.edu

Climate-driven changes are having profound impacts on coastal ecosystems, like the Morro Bay Estuary
pictured in the above photo. 
 

SAN LUIS OBISPO — Coastal ecosystems worldwide are more resilient to climate change stressors than previously reported, according to a study led by Cal Poly and California Sea Grant biologist Jennifer O’Leary.

The results indicate that certain management tools, such as marine protected areas (MPAs), may benefit ecosystems by increasing resilience. This could mean that Central Coast MPAs, established in 2007, will help buffer the effects of climatic change into the future.

O’Leary and her colleagues surveyed 97 coastal ecosystem experts to determine the factors that promote and prevent resilience. Climate-driven changes are having profound impacts on coastal ecosystems, she said. Many crucial species are in sharp decline. However, examples of resilience are emerging.

Jennifer O'Leary.

“Bright spots of ecosystem resilience are surprisingly common across six major coastal marine ecosystems, with 80 percent of experts witnessing resilience during their careers,” O’Leary said.

As the research team reports in the journal BioScience, some areas demonstrated striking recoveries. In Western Australia, up to 90 percent of live coral died due to high water temperature. Despite reaching a low of 9 percent coral cover, the reef surface recovered to 44 percent coral cover within 12 years, she said.

The factors that contribute to resilience the most often are retention of native habitat after climatic disturbance and arrival and survival of new juveniles to recreate lost habitat. Sound local management practices also played a role. The authors argue that if marine protected areas are spaced appropriately, it may be possible to mitigate some of the climatic damage to ecosystems.

“This is hugely relevant to California generally where our new system of MPAs may help increase coastal resilience by protecting kelp forests and promoting better connections between the coast and undisturbed habitat,” O’Leary said.

For example, Morro Bay estuary has experienced a 95 percent loss of eelgrass over the last 10 years, but, according to O’Leary, this study provides hope that the ecosystem may recover, as not all eelgrass was lost. Cal Poly and the Morro Bay National Estuary Program have identified new eelgrass plots emerging, a sign of potential recovery.

O’Leary and her colleagues caution that local bright spots do “not contradict the overwhelming evidence that climatic impacts present a major stressor to coastal ecosystems,” although they do provide an optimistic outlook if coastal ecosystems are managed to reduce the effects of climatic stress.