Mexico Marine Life Makes Astounding Recovery

Results of their 10-year analysis of Cabo Pulmo revealed that the total amount of fish in the reserve ecosystem — the biomass — boomed by more than 460 percent from 1999 to 2009. Citizens living around Cabo Pulmo, which was previously depleted by fishing, established the park in 1995 and have strictly enforced its "no take" restrictions.

"We could have never dreamt of such an extraordinary recovery of marine life at Cabo Pulmo," said Enric Sala, the National Geographic explorer-in-residence who started the study in 1999. "In 1999, there were only medium-sized fishes, but 10 years later it's full of large parrotfish, groupers, snappers and even sharks."

Striking results

The most striking result of the study, the authors say, is that sea creatures at a depleted site can recover up to a level comparable to remote, pristine sites that have never been fished by humans.

"The study's results are surprising in several ways," said Octavio Aburto-Oropeza, a Scripps postdoctoral researcher and lead author of the study. "A biomass increase of 463 percent in a reserve as large as Cabo Pulmo (71 square kilometers) represents tons of new fish produced every year. No other marine reserve in the world has shown such a fish recovery."

The paper notes that factors such as the protection of spawning areas for large predators have been key to the reserve's robustness. Most importantly, local enforcement, led by the determined action of a few families, has been a major factor in the park's success. Boat captains, dive masters and other locals work to enforce the park's regulations and share surveillance, fauna protection and ocean cleanliness efforts.

"We believe that the success of CPNP is greatly due to local leadership, effective self-enforcement by local stakeholders, and the general support of the broader community," the authors wrote in their report.

Local impacts

Strictly enforced marine reserves have been proven to help reduce local poverty and increase economic benefits, the researchers say. The national park's marine life recovery has spawned eco-tourism businesses, including coral reef diving and kayaking, making it a model for areas depleted by fishing in the Gulf of California and elsewhere.

"The reefs are full of hard corals and sea fans, creating an amazing habitat for lobsters, octopuses, rays and small fish," said Brad Erisman, a Scripps postdoctoral researcher and co-author of the article. "During some seasons, thousands of mobula rays congregate inside the park and swim above the reef in a magnificent way."

The scientists have been combining efforts to monitor the Gulf of California's rocky reefs every year for more than a decade, sampling more than 30 islands and peninsula locations along Baja California, stretching from Puerto Refugio on the northern tip of Angel de la Guarda to Cabo San Lucas and Cabo Pulmo south of the Bahia de La Paz.

During the 10 years of study, the researchers found that Cabo Pulmo's fish species richness blossomed into a biodiversity "hot spot." Animals such as tiger sharks, bull sharks and black tip reef sharks increased significantly. Scientists continue to find evidence that such top predators keep coral reefs healthy. Other large fish at Cabo Pulmo include gulf groupers, dog snappers and leopard groupers.

The study was published in the journal Public Library of Science (PLoS) ONE.