By Chris Palmer
A decade-long ban on fishing in a marine park in southern Baja has resulted in a dramatic resurgence of ocean life, according to Scripps Institution of Oceanography Postdoctoral Researcher Octavio Aburto-Oropeza. Aburto-Oropeza showcased the success of Cabo Pulmo National Park to a near-capacity audience at January’s Jeffrey B. Graham ‘Perspectives on Ocean Science’ lecture hosted by the Birch Aquarium.
Aburto-Oropeza’s lecture, ‘Marine Protected Areas: A Success Story’, detailed the restoration of Cabo Pulmo since it became a marine protected area in 1995 and featured stunning photography of the region. Aburto-Oropeza cited Cabo Pulmo, a now-thriving undersea park near the southern tip of Mexico's Baja peninsula, as an example of how marine reserves can flourish given the proper protection.
“For me, this area is like a time machine. I am now able to see all of these species that I only read about in the literature,” he said.
Over the course of hundreds of scuba dives in 1999 and 2009, Aburto-Oropeza and a team of Scripps researchers inventoried the amount of fish biomass (a measure that reflects the number of fish and their individual sizes) in the waters near Cabo Pulmo, as well as several nearby marine protected areas. To the researchers’ surprise, fish biomass in Cabo Pulmo increased by 463 percent over the decade, the largest such increase ever recorded in a marine protected area. In contrast, the neighboring protected areas showed almost no increase in fish biomass over the same period of time.
In addition, the number of predators in Cabo Pulmo increased by nearly 1,000 percent from the initial 1999 count, which is significant given that research has shown that ecosystems top-heavy in predators tend to be the most sustainable. The average size of individual predators also increased.
“The largest predators in the Gulf of California are now in Cabo Pulmo,” said Aburto-Oropeza.
The difference between Cabo Pulmo and the other protected areas in the Gulf? The entire area of Cabo Pulmo has been declared a “no-take” area where fishing has been banned, whereas considerably smaller portions (close to 1 percent) of the nearby areas have been designated as no-take. Such small no-take zones are the norm for the vast majority of the world’s 5,000 or so marine protected areas.
“Cabo Pulmo confirms that by using no-take marine preserves we can protect endangered species,” said Aburto-Oropeza, who hopes that conservationists can apply the lessons learned in Cabo Pulmo to the broad network of marine reserves that went into effect in last fall in Southern California amid criticism that such areas do not produce a significant amount of marine life.
Initially, only one-third of Cabo Pulmo was no-take. Credit goes to the local population of Cabo Pulmo for initiating the expansion of the area to 100% no-take, making it, at a mere 71 km2, 70 times larger than the average no-take protected area.
“The local people changed their lifestyle. They left their nets and fishing boats and decided to protect the reefs,” said Aburto-Oropeza, adding that the economic benefits of embracing tourism over fishing have been significant.
The locals still fish, but only outside the borders of the national park. “They know the beauty of the land and the ocean will attract more and more visitors in the coming years and will generate enough work to sustain their community in the long term.”
In spite of the success of Cabo Pulmo, Aburto-Oropeza sees worldwide ocean productivity collapsing at an ever-quickening rate due to pressure from fishing as well as from coastal development. For example, in Cancun estuaries, mangrove forests, which are spawning grounds for some fish species, have been cleared for development, devastating those fish species.
Even Cabo Pulmo could be in danger. A 30,000-room hotel development is planned for Cabo Pulmo, but for now, financial difficulties for the developers have given the region, and its inhabitants, a reprieve.
• Aburto-Oropeza’s lecture can be viewed online at ucsd.tv/oceanscience/
• On Feb. 13, marine biologist Heidi Dewar will discuss how high-tech tools used to track the complex behaviors of fish advance conservation, 6:30-8 p.m. $8-$5.
RSVP: (858) 534-5771