A recently completed study on the effectiveness of marine protected areas off the California Coast have shown some promising results but scientists now say the expected rebound in fish stocks will take some time.
The recently released joint study between Cal Poly and the California Sea Grant suggests that the Central Coast’s MPAs “may eventually produce more and larger fish than areas open to fishing, but the benefits could take time to accrue,” reads a news release from the study group.
The study looked at the first 7 years of monitoring within four MPAs strung between San Francisco and Morro Bay.
“The study found few significant differences between fish populations inside and outside three of the MPAs, which were established in 2007. However, Point Lobos State Marine Reserve, which has been protected since 1973, is flourishing with more and bigger fish than its surrounding areas.” The research was published in March in the journal PLoS One.
“These marine reserves are going to work, but they’re not a short-term solution for commercial fisheries,” said Rick Starr of California Sea Grant and lead study author.
Starr and Dean Wendt, dean of research at Cal Poly, led a team of marine researchers and more than 700 volunteer fishermen to sample fish both in and out of four protected areas: Año Nuevo State Marine Conservation Area, Point Lobos, and the Piedras Blancas and Point Buchon State Marine Reserves. Point Buchon reserve is off Montaña de Oro State Park, covering many square miles.
“We didn’t see much change that could be attributed to the MPA status,” Starr said of the data in the study.
Starr and Wendt think part of this trend might be attributable to “good conditions for fish outside the reserves.”
Stringent fishery regulations in California over the past decade have reduced fishing pressure, while ocean conditions favored successful reproduction for many of the species in the study, they said.
MPAs provide a refuge for marine life where little or no harvesting is allowed. The theory about MPAs is that eventually fish will rebuild their population size and spill over to the surrounding ocean, thus helping to replenish commercial fish stocks.
With MPAs it appears that success depends on where the protected areas are established.
“Early research on MPAs came from tropical areas,” Starr said, “where fish tend to have a shorter lifespan and are fast breeders. When you protect those areas, they rapidly rebuild their population. It can take as little as 3 to 5 years. We didn’t see those results in cold Central California waters. Some of the fish here live for more than 50 years, growing and breeding slowly.”
Other reserves in California, where ocean conditions vary widely, have behaved differently. MPAs near the Channel Islands saw a rebound of fisheries in just 5 years, although Starr admitted that these results were primarily for short-lived or fast-growing species.
Despite the mixed results so far, the goal of the project is to “work with agencies and fishermen to use the monitoring results for better fisheries management.”
Wendt said, “Our goal is to improve conservation and economic outcomes for California fisheries by building strong partnerships among fishermen, scientists, non-governmental organizations and resource managers.”
Starr and Wendt plan to meet with fishermen and state fishery managers to work on a management plan that includes the expertise and participation of non-agency stakeholders. Wendt said these kinds of partnerships offer a number of benefits, including more eyes on the water to notice changes in the fisheries and better cost-effectiveness at gathering data.
“A study of this size would not have been possible without the help of more than 700 fishermen,” said Wendt. “We hope what we learned over the last seven years can help Californians strengthen our fisheries for the future.”
To learn more or become involved in the fisheries management plan, email Starr at: or call (831) 771-4442 or Wendt at: or (805) 756-1508.