Marine Protected Areas

image of kelp forest by chad king

Interest in marine protected areas (MPAs) has rapidly increased as state, federal and international management agencies and stakeholders consider their application for ecosystem-based management and ocean conservation. MPAs are spaces in the ocean where human activities are more strictly regulated than surrounding waters. A special type of MPA, called a marine reserve, prohibits fishing and development activities. An underlying motivation for MPAs is that they are one of the management strategies to increase productivity, enhance resilience, and conserve biodiversity. 


Marine reserves and other protected areas in the coastal ocean are established in both California and Oregon, acting as sentinel sites for researching the state of the ocean and educating citizenry about these findings. PISCO’s broad-scale coordination of research, monitoring, data management, training, and outreach enables research into the effectiveness of these areas and effective communication of this science to different audiences, including policy makers and managers. We work closely with agency partners to develop monitoring and assessment programs to better understand how these and surrounding areas respond to protections.


Scientific understanding of marine reserves and other protected areas is growing rapidly. PISCO scientists have actively worked to develop a better understanding of the roles and design of MPAs for ecosystem-based management and conservation. Activities include working groups and meetings to synthesize the science of marine reserves. These, as well as PISCO-generated data, have spawned a number of publications in the scientific and policy literature as well as outreach materials for the general public. This work has resulted in new knowledge, such as general basics about MPAs:

  • Rules of thumb for MPA network design: MPAs should encompass a variety of marine habitats across a range of depths and environmental gradients. PISCO's monitoring programs have helped to elucidate how ecosystems and the communities they support vary across space and time. This information has been used to define biologically distinct regions and, in California, to help identify the scales across which habitats should be represented within MPAs for effective protection of the full diversity of marine communities in California.
  • Movement of species from inside to outside MPAs: The movement range of fish and invertebrate species has implications for MPA size guidelines. By understanding the mobility of a wide range of species, scientists can predict which species will likely be protected by an MPA of a given size.
  • Dispersal from one MPA to the next in a network of protected areas: PISCO's genetic and recruitment studies have helped to describe larval dispersal distances and inform development of MPA networks in California. We continue to conduct ecological and genetic sampling as well as modeling to test predictions of connections among populations and evaluate the extent to which individual MPAs are connected to form a network. 


PISCO is committed to communicating the science of marine reserves and other protected areas to the public, managers, and policy makers in an active, two-way dialog. We work to inform decision making with accurate science and do not advocate for particular policy and management outcomes. PISCO scientists regularly participate as science advisors to local, state, federal, and international processes. Examples include California's Marine Life Protection Act, Oregon's Ocean Policy Advisory Council, the National Marine Sanctuaries, the Federal Center for Marine Protected Areas, and others.


PISCO scientists are involved in the design and implementation of studies to monitor and evaluate the effects of MPAs in both California and Oregon. The California Marine Life Protection Act established an MPA network covering 16 percent of state waters. Eight percent of Oregon state waters are protected through MPAs and marine reserves. Further complementing these protected areas are conservation areas established through other legislative measures for shoreline and state water conservation.

Common to both state systems are interests to assess how the MPAs are working toward specific conservation goals. PISCO investigators collaborate closely with state agencies and other organizations to design and evaluate marine reserves and other protected areas. Because PISCO had established monitoring sites in many areas prior to the implementation of protected areas, PISCO’s program has been critical in providing long-term data beyond initial baseline data collection periods. PISCO investigators also lead ongoing data collections in marine reserves, protected areas, and comparison areas and perform analyses to directly inform MPA evaluations. We also actively advise the state agencies charged with implementing the reserves about methods development and long-term ecosystem monitoring strategies. Types of questions posed by PISCO investigators include:

  • How well will an ecosystem be protected if a specific fishing activity is allowed within an MPA?
  • Do MPAs alter the population abundance and size structure of fished species? How do those results vary among species, MPAs, and why?
  • What is the amount of habitat that should be protected to encompass the majority of habitat-associated biodiversity?
  • How do the structural and functional attributes of communities change in and out of reserves over time?
  • What are patterns of connectivity among reserves? To what extent is a marine reserve network's effectiveness reliant on connectivity and recruitment?



The Science of Marine Reserves booklet series: an international collaboration to study, synthesize, and share scientific information about marine reserves around the world.

Ten Years of Change at the Channel Islands: After ten years of monitoring within a network of Marine Protected Areas (MPAs) in the northern Channel Islands, a new series of analyses show changes in subtidal rocky reef and kelp forest habitats.


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To learn more about PISCO's long-term studies, read about our work in the coastal oceankelp forests, and rocky intertidal. Also access our sampling protocols and data.