Channel Islands' Marine Protected Areas after Ten Years

image of a part of 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. A four-page booklet "Ten Years of Change at the Channel Islands" summarizes these findings. Overall, sea life inside these reserves is bigger and more abundant than outside the reserves. The booklet also describes how different MPAs performed and discusses the complexities of identifying the effects of MPAs across environmental gradients.

PISCO scientist Jennifer Caselle from University of California Santa Barbara leads this subtidal research in the Channel Islands.


In 2003, a network of MPAs was implemented in the northern Channel Islands, home to the Channel Islands National Marine Sanctuary and the Channel Islands National Park. Now part of the South Coast region of the Marine Life Protection Act, these MPAs celebrated their anniversary in 2013.

In 2008, a five-year evaluation was done, and results were presented at a special symposium and distributed in a summary report. Many research, agency, citizen science and fishermen groups contributed to this evaluation and all agreed that while five years was not enough time to see dramatic changes in the ecosystem, interim results can be useful in providing a glimpse of the changes that might come as well as the types of information that are used in evaluating MPA effectiveness. The 2008 five-year report documented patterns in the communities of animals occupying shallow kelp forests to deepwater habitats as well as changes to both recreational and commercial fisheries.

In 2014, analyses were completed of the past ten years (2003-2013) of shallow rocky reef and kelp forest monitoring in the northern Channel Islands. These analyses update the five-year evaluation of these habitats aand are now available in the new booklet "Ten Years of Change at the Channel Islands.


PISCO has monitored the rocky reef and kelp forest ecosystems in the northern Channel Islands MPAs for over a decade, beginning in 1999. Other groups have also historically monitored these areas, including the National Park Service, ReefCheck CA, and Marine Applied Research Expedition (MARE). The South Coast MPA Baseline Program began in 2012, when the broader South Coast MPA network was established. In this program, scientists, fishermen, and citizen science groups are working together to establish a benchmark that highlights ecological ocean conditions and human uses when the South Coast MPA network took effect. For more information about South Coast MLPA activities, visit. The data presented in "Ten Years of Change at the Channel Islands" are from PISCO's monitoring program.


"Ten Years of Change at the Channel Islands" updates the 2008 results on the patterns of kelp forest organisms inside and outside MPAs. The five-year review of the CI MPA network focused primarily on spatial patterns and less on changes over time. The latest 10-year results indicate that the initial positive trends seen in 2008 are continuing. The five-year review showed that abundance (numbers of fish) and biomass (total weight of fish) of fish species targeted by in the region were both greater inside the reserves relative to the outside reference sites. Non-targeted fish species did not show these same differences between MPA and open areas. This ten-year review now shows the same patterns with even larger differences between protected and unprotected sites. Other findings explained in the brochure are:

  • Fish and invertebrates are bigger and more abundant. Fish species traditionally targeted by fishermen have increased in biomass (total weight per area, both size and number of organisms) inside and outside of the MPAs; the increase is much more pronounced inside the MPAs.
  • Shifts in fishing effort do not appear to be affecting fish populations in open areas adjacent to MPA boundaries. The increase in biomass of targeted species in reference areas outside of MPAs suggests that redistributed fishing effort is not exhausting these species in areas close to, but outside of, MPA boundaries. Altered fishing patterns, fish spillover from MPAs, changes in ocean conditions, or a combination of these and other factors could be contributing to this observed increase.
  • Highly targeted species (e.g., spiny lobster, red urchin) are more abundant inside the reserves, while unfished or lightly fished species do not show any consistent patterns of change inside and outside the MPAs.
  • Overall, sea life inside these reserves is bigger and more abundant than in fished areas. However, not all MPAs perform in a similar manner. Environmental conditions, fishing patterns, and other variables are important when considering observed changes and evaluating MPA performance.


MPAs are natural laboratories where research can be done to inform management of coastal resources in the face of climate change, ocean acidification, and other looming challenges. These results from the northern Channel Islands contributes to the body of knowledge and understanding of California's South Coast region. Over the next year, results from the South Coast MPA Baseline Program will be integrated with this and other research and monitoring activities in the region to develop a comprehensive picture of the region – a benchmark against which future changes can be measured.


PISCO kelp forest monitoring could not occur without substantial support from a large number of partners and funders. These include: David and Lucile Packard Foundation, Gordon and Betty Moore Foundation, Channel Islands National Park, NOAA, National Science Foundation, CA Department of Fish and Wildlife, Channel Islands National Marine Sanctuary, CA Ocean Protection Council, CA Sea Grant, and Resources Legacy Fund.