Research Highlight: Early Results Suggest California Marine Protected Areas are a Success

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A network of marine protected areas (MPAs) in California is showing signs of success in the form of more and larger fish and invertebrates, according to a new study published in the peer-reviewed journal Ocean and Coastal Management.

Samantha Murray of Scripps Institution of Oceanography at the University of California San Diego and Tyler Hee of environmental law firm DeLano and DeLano said their analysis demonstrates that California’s significant investment in MPA management with a focus on scientific monitoring, interagency coordination, public education and outreach, and enforcement provides an important case study that can guide similar efforts in MPA creation and management in other parts of the world.

“The story of creating California’s MPAs is globally recognized as an innovative, stakeholder-driven planning effort,” said Murray, executive director of the Master of Advanced Studies Program in Marine Biodiversity and Conservation (MAS MBC) at Scripps. “But this is the first paper to shine a light on the comprehensive management program California has implemented since the MPA network was completed in 2012. We applaud the visionary leadership that California agencies, legislators, and partners have demonstrated in adopting and implementing the most well-rounded, start-to-finish MPA program in the world.”

There are now 124 MPAs covering 852 square miles, or 16 percent of California state waters. Initial monitoring results show more and bigger fish, especially in older MPAs where the benefits of limiting fishing have had longer to accrue. Murray and Hee, a 2018 graduate of the MAS MBC program, found evidence of rebounding ecosystem health in several of them, ranging from an increase of commercially important fish species such as lingcod and black rockfish in the state’s central coast to a 52-percent increase of biomass – or total marine life – in reserves off the Channel Islands. Significantly, ocean waters just outside those reserves also experienced a 23-percent increase in biomass. These data, along with information collected in San Diego, Carmel Bay and Monterey Bay, suggest that MPAs are having the intended spillover effect into areas accessible to fishermen. The authors note, however, the full suite of ecological benefits from MPAs will likely be realized in the coming years.  

Murray noted that while the creation of the protected areas in itself was an important step, it is California’s significant financial investment and wide-ranging management activities that set the effort apart from all other networks globally. Resource agencies, Native American tribes, researchers, educators, businesses, and fishing, conservation, and community organizations have all engaged in a comprehensive range of programs and efforts designed to support effective long-term monitoring and enforcement of the state’s marine protected areas. For example:

  • Scientists are using the MPA network to study climate change impacts on the ocean and sustainable fisheries.

  • Recreational anglers catch and tag fish inside and outside MPAs to study the results of marine protections.

  • Mobile apps tell fishermen where the MPAs are and emerging technologies are being used to help identify poaching hotspots.

  • State, local, and federal agencies consider MPAs in evaluating coastal development projects.

  • The state legislature has passed two laws to bolster MPA enforcement efforts.

  • School groups engage in citizen science projects to survey beach and intertidal habitats.

Though some marine protected areas already dotted the California coastline, the state began creating the current network in 2004 in response to the Marine Life Protection Act, a state law adopted in 1999. The eight-year process involved hundreds of regional meetings at which sportfishermen, Native American tribes, surfers, divers and a range of other interests gave input. The final product is the country’s first statewide, science-based MPA network. The authors note that the state has applied for recognition of the network in the International Union for the Conservation of Nature Green List for Protected and Conserved Areas. 

Since California's marine protected area network was completed in 2012, there has been a steady rise in the establishment of protected areas throughout the world in response to international ocean protection targets such as the 2011 Convention on Biological Diversity Aichi Target 11 and U.N. Sustainable Development Goal 14, which call for 10 percent of global ocean protection by the year 2020.

As the use of MPAs expands internationally, so have warnings against “paper parks,” unmanaged and unenforced MPAs that may not provide the full range of conservation benefits. These global MPA targets and related cautions underscore the importance of sharing California's post-designation MPA management actions, as well as the value that the efforts undertaken to date will have for California’s marine life.


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