Authors: Bryn Power, CSU COAST Science-Policy Intern, and Hayley Carter, Senior Science Officer, California Ocean Science Trust

Photos: Michael Langhan

Expanding the Tools Available to Tackle Our Changing Ocean 

In California, climate change poses risks to California’s commercial and recreational fishing industries, public health, tourism, coastal protection, as well as ecosystem structure and function. From marine heat waves, harmful algal blooms, sea-level rise, kelp forest loss, and ocean acidification, coastal systems face new and ongoing challenges from a changing climate. In looking for ways to expand the tools available to us to deal with the effects of climate change, a growing body of research is focused on advancing our understanding of the role of MPAs in helping species cope and recover from climate-related impacts.

MPA monitoring survey in progress. 

Can MPAs Support Climate Resilience? 

While there are many definitions of “resilience,” in this context we refer to climate resilience as the ability of species or ecosystems to remain intact or recover from disturbance related to changing ocean conditions. Bolstering species’ abilities to bounce back from climatic impacts will likely have a cascading effect of improving the overall ecosystem’s resilience. MPAs protect a variety of habitats, communities, and ecosystems, and may harbor populations of species that can re-seed locations subject to extreme climate-related events like die-offs related to marine heatwaves (e.g., kelp forest loss) or disease (e.g., abalone withering syndrome syndrome and sea star wasting). MPAs may also protect genetic diversity hotspots and allow for naturally more resistant variants to thrive and repopulate other more sensitive locations.  

While an active area of study, to date very few examples exist of MPAs providing climate resilience. Answering this question requires substantial long-term monitoring information, and many protected areas have only just recently been established. However, some areas along our coast have been protected regions for a lot longer – including the Channel Islands – which can give us a window into what climate effects we may expect from California’s MPA network as a whole in the future. 

Healthy kelp ecosystem.

Case Study: Channel Islands MPAs Support a Healthy Kelp Forest Ecosystem as Oceans Warm

In Southern California, Northern Channel Islands kelp forests have been destroyed by an invasive species of alga, Sargassum horneri, which has increased in prevalence as our ocean warms. The invasive alga feed on giant kelp and other key algae that work together to ensure a functioning kelp forest ecosystem. When a species of purple sea urchin, Strongylocentrotus purpuratus, is abundant in the area, invasive algae thrive in place of the native algae. However, in no take MPAs in the region, predators of the sea urchin, the spiny lobster, Panulirus interruptus, and the California sheephead, Semicossyphus pulcher, are abundant, and act to balance the amount of sea urchins present, therefore keeping the kelp forest ecosystem intact. In comparison, outside of the marine protected areas, where those two predators of the sea urchin are fished, native and invasive alga populations are greatly reduced, and the kelp ecosystem is much weaker. Therefore, the establishment of an MPA has indirectly strengthened the ecosystem, and with increasing weakening of ecosystems due to climate impacts such as ocean acidification and hypoxia, any ecosystem strengthening is beneficial to keep them as intact as possible. 

Urchin barren.

To read more examples of resilience and protected areas around the world, check out the full federal advisory committee report, co-authored by UC Santa Cruz researcher Dr. Mark Carr (here)

New Expert Science Group At the Ready

As we face uncertain and growing climate-related threats along our coast, we must continue to explore ways to apply a climate lens to all the natural resource management tools available to us. California is committed to furthering our understanding of the MPA network’s potential to provide ecosystem resilience against climate driven impacts and has recently established an expert science working group to tackle this issue. Convened by the Ocean Science Trust with funding from the Ocean Protection Council, the group will address: What could we know if we analyzed existing monitoring and research data in new ways? And what could we invest in to efficiently grow our scientific understanding on this topic? For more information about the working group see here

We look forward to keeping the MPA community up to date as we learn more over the coming year. 

Subtidal survey of algae and invertebrates.

Photo Credit: Steve Lonhart/NOAA MBNMS

About Ocean Science Trust

Ocean Science Trust is a nonprofit organization, created by legislation, and staffed by a team of science-to-policy experts based jointly in Sacramento and Oakland. We work statewide and collaborate with scientists and policy leaders across the West Coast and nationally. To learn more, visit