Baja Fishers Work to Conserve Loggerhead Foraging Grounds

Fishermen from Puerto López Mateos, Baja California Sur, satellite track a loggerhead on her trans-Pacific journey. © GRUPO TORTUGUERO

Fishermen from Puerto López Mateos, Baja California Sur, satellite track a loggerhead on her trans-Pacific journey. © GRUPO TORTUGUERO

By Hoyt Peckham, Johath Laudino Santillán and Wallace J. Nichols

The small Mexican fishing community of Puerto Lopez Mateos has a big influence on loggerhead sea turtle conservation. Facing a massive bycatch problem in their halibut and shark fisheries, fishermen are partnering with researchers to better understand sea turtles and to avoid turtle bycatch.

Adult loggerheads in the North Pacific nest exclusively on Japanese beaches, but their juvenile migrations can span the entire Pacific Basin. Some travel more than 10,000 kilometers (6,213 miles) to the west coast of North America. On reaching maturity, they return to Japanese coasts to reproduce.

The legendarily rich waters of Baja California Sur attract thousands of juvenile loggerheads to feed and mature. However, these waters are also a place of intense fishing, where catastrophically high bycatch occurs. This bycatch is one of the greatest known threats to the critically endangered North Pacific loggerhead population—one of the 10 most threatened sea turtle populations in the world, as identified by the IUCN Marine Turtle Specialist Group.

Demographic models suggest that bycatch in this hotspot may preclude the North Pacific loggerhead population’s recovery. Local fishermen accidentally kill as many as 30 loggerheads per day, per boat. In 2005 alone, conservationists estimate that more than 900 loggerheads died in fishing nets in just two of the region’s fleets. The fishermen reported, however, that they catch loggerheads only in certain areas.

In 2003, the Grupo Tortuguero formed a task force of local fishers, community members, and managers to study turtle habitat use and to design and conduct experiments to reduce turtle bycatch. Ultimately, they developed a research program to engage local fishers in understanding, assessing, and reducing their bycatch.

The task force deployed more than 40 satellite transmitters and tracked turtles to better understand if loggerheads congregate in specific areas. The research revealed that although they range widely throughout their lifetimes, juvenile loggerheads off the Baja California Peninsula spend most of their time in a narrow feeding hotspot that overlaps with massive swarms of their primary prey, the pelagic red crab.

This map shows satellite telemetry data from a loggerhead known as Adelita, the first sea turtle ever tracked on a trans-Pacific journey. Adelita was released in Santa Rosalita, Baja, Mexico, and tracked to the Japanese coast before her satellite transmitter stopped sending signals. She most likely became caught in fishing gear and drowned. Adelita’s journey was recorded in 1996 by researchers Wallace J. Nichols, Jeffrey Seminoff, and Antonio and Beatris Resendiz.

This map shows satellite telemetry data from a loggerhead known as Adelita, the first sea turtle ever tracked on a trans-Pacific journey. Adelita was released in Santa Rosalita, Baja, Mexico, and tracked to the Japanese coast before her satellite transmitter stopped sending signals. She most likely became caught in fishing gear and drowned. Adelita’s journey was recorded in 1996 by researchers Wallace J. Nichols, Jeffrey Seminoff, and Antonio and Beatris Resendiz.

Testing of various types, sizes, arrangements, and locations of gillnets demonstrated that loggerheads are caught almost exclusively within the hotspot. The tests ascertained that the only reliable method of preventing turtle bycatch is to avoid fishing with bottom-set gillnets and longlines in the hotspot.

In March 2006, the community task force combined local ecological knowledge with these new data to declare the loggerhead hotspot a “fisher’s turtle reserve,” where turtle ecotourism can thrive and where locals work to eliminate loggerhead bycatch by changing their fishing techniques.

Since then, the Grupo Tortuguero has worked with state and federal authorities to formally establish the turtle reserve as a federally protected refuge zone that will give local fishermen the authority to defend turtles in the area from destructive local and outside fishing practices. During summer 2006, several fishing crews left nets and hooks ashore to take ecotourists to sea to witness the natural beauty of loggerheads in their waters.

Long-term solutions to mitigate bycatch must be based on good science, policy, and enforcement, but ultimately success derives from fishers’ direct interest and participation. The capacity to conduct and apply research and to enforce legislation for bycatch reduction in Baja California Sur is limited—as it is in many coastal fisheries around the world. The Grupo Tortuguero demonstrates the power of a small cadre of committed local citizens to effect change when they steward the resources on which their livelihoods depend.