Marine protected areas were not designed for climate resilience

As climate change intensifies, so does the urgency to protect our planet’s precious marine ecosystems. An international team of experts has risen to the challenge by devising the first comprehensive framework for creating networks of marine protected areas (MPAs).

The goal of the research is to help protect vulnerable species amidst the pressures of climate change-induced habitat loss.

Critical timing

Stanford marine conservation scientist Nur Arafeh-Dalmau led this ambitious project, which involved 50 scientists and practitioners from agencies in the U.S., Mexico, and Australia.

Their proposed guidelines arrive at a time when nearly every country around the world has committed to protecting 30% of both land and sea by 2030. 

Significant oversight 

While marine protected areas, and their terrestrial counterparts, aim to connect habitats fractured by human interference and the unpredictable ravages of climate events like wildfires, there has a significant oversight. 

“Until now, marine protected areas have been designed for biodiversity conservation, but not necessarily for climate resilience,” said Arafeh-Dalmau. “They suffer from climate impacts but aren’t designed to endure them.”

Southern California Bight 

For a detailed case study, the team focused on the Southern California Bight. This region, marked by the gradual curve of California’s coastline stretching into Baja California, Mexico, supports a rich ecosystem. 

Its giant kelp forests, vital to numerous commercially and culturally significant species, are under threat from marine heatwaves and reduced oxygen levels. These factors have already impacted critical fisheries, such as the jumbo squid and abalone, threatening local communities’ livelihoods.

Under-protected waters

While California boasts marine protected areas covering 16 percent of its state waters, with half being fully protected, Baja California’s waters remain under-protected, with less than one percent prohibiting activities like fishing. 

Moreover, current MPA networks don’t adequately account for species migration across U.S. and Mexico boundaries, leading to potential losses in conservation efforts.

“We designed a systematic approach to help resource managers stay ahead of the curve and anticipate rather than react to climate change,” said co-lead author Adrian Munguia Vega, a genomics researcher at The University of Arizona. 

“A big part of that is showing how entire marine ecosystems and the species that inhabit them are connected by ocean currents that do not stop at the international border. Thus, we need coordinated efforts and protections across political boundaries.”

Redefining marine conservation

The authors advocate for the integration of climate adaptations into the MPA planning process. By factoring in anticipated climate scenarios, conservationists can create more resilient protections against worsening marine conditions. 

In addition to habitat diversity, the researchers prioritized habitat persistence. These habitats, known as “climate refugia,” can provide consistent relief for species faced with extreme thermal shocks.

“Climate extremes don’t stop at the boundary of a marine protected area,” said co-author Fiorenza Micheli, chair of the Oceans Department and co-director of the Center for Ocean Solutions. “If California’s network of marine protected areas had been designed with climate considerations, it would look different.”

Alarming potential outcomes 

For their study, the researchers analyzed satellite imagery spanning decades to gauge the persistence of giant kelp along the Southern California Bight. They discovered alarming potential outcomes: marine heatwaves in the upcoming five decades could drastically fragment suitable habitats for marine larvae. 

As a result, ecological connectivity could plummet by 50 percent, with population densities witnessing a possible decline of up to 90 percent.

In a departure from conventional conservation strategies that focus on areas with maximum kelp species, the new framework prioritizes areas where kelp – and by extension, other marine life – has the highest survival likelihood. 

Stepping stone strategy 

The experts recommend a series of protected areas, or “stepping stones,” that link isolated populations like beads of a necklace along the Southern California Bight.

“This stepping stone strategy can be very cost-effective and cheaper for everyone,” said Arafeh-Dalamu, who documented Mexico’s worst marine heat wave from 2014 to 2016. 

“Maybe you need fewer areas to be protected if you are protecting the important areas.” Plus, the collaboration between countries can strengthen research capacity, and ideally, diplomacy, noted Arafeh-Dalamu.

“We have the information and tools to design and implement marine conservation in a way that explicitly and proactively accounts for climate change,” said Micheli. “Now is the time to understand where we strategically invest in expanding and strengthening protection so these ecosystems have a future.”

The study is published in the journal One Earth. 

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