Photo by Ben Wicks

Marine Protected Areas significantly enhance kelp forest recovery following severe marine heatwaves, according to new research that provides evidence for ocean protection as a climate adaptation strategy.

Satellite analysis reveals protection benefits

UCLA researchers analysed four decades of satellite imagery comparing kelp forests inside and outside 54 Marine Protected Areas along California’s coast. While overall MPA effects were modest, benefits became clear after the devastating 2014-2016 marine heatwaves.

“We found that kelp forests inside MPAs showed better recovery after a major climate disturbance,” said lead author Emelly Ortiz-Villa. “Places where fishing is restricted and important predators like lobsters and sheephead are protected saw stronger kelp regrowth.”

The recovery effect was strongest in Southern California, where fishing restrictions preserve predator species that control sea urchin populations – the primary kelp grazers.

Climate adaptation tool

The study, published in the Journal of Applied Ecology, suggests MPAs serve as crucial climate adaptation tools as marine heatwaves intensify.

“Kelp forests can be remarkably resilient to individual stressors, but multi-stressor situations can overwhelm their capacity to recover,” said senior author Kyle Cavanaugh. “By mitigating certain stressors, MPAs can help enhance kelp resilience.”

Ecosystem protection through food webs

The protection works through trophic cascades – fishing restrictions preserve California sheephead and spiny lobsters that keep sea urchin populations in check. This natural balance prevents urchins from overgrazing kelp forests.

However, effectiveness varies by location. Professor Rick Stafford noted the results “demonstrate the need for effective MPAs,” as many designated areas lack comprehensive management or even permit destructive practices like bottom trawling.

The findings offer practical guidance as nations work toward protecting 30% of oceans by 2030, showing well-designed marine protection can help ecosystems withstand escalating climate pressures.