Once abundant and visible in large aggregations, the charismatic scalloped hammerhead sharks have nearly disappeared from the Sea of Cortez. Due to targeted commercial fishing, the scalloped hammerhead and other large shark populations of the Sea of Cortez collapsed by the early 2000s, and the species was considered ecologically extinct in seamounts where they were most abundant. It is believed that the great hammerhead has been completely wiped out from the Sea of Cortez. With our partners from Pelagios Kakunjá, researchers collected observations from divers over the last 50 years and found that scalloped hammerhead sharks (Sphyrna lewini) have been reduced by 97-100% at the two seamounts where they were most common.
Tracking Hammerheads, their loss and economic value
Through research with acoustic and satellite tags the team has demonstrated that the seamounts and submerged ridges provide important habitat, and a migratory highway, for scalloped hammerhead sharks. Other species of importance in the area between the eastern Cape and the southern islands include whale sharks, great hammerhead sharks, grey whales, green sea turtles, endemic mobula rays and other large fish.
In a socioeconomic survey, divers including famed conservation photographers Howard Hall and Marty Snyderman (as seen in the film Sharks of the Sea of Cortes’: A Lost Treasure), reported seeing an average of 150 sharks at El Bajo and 100 sharks at Las Animas, per dive in the 1970s. The same divers reported seeing only five sharks per dive at El Bajo and none at Las Animas in the 2010s.
The Hammerhead Highway
Our project aims to help recover the shark populations and the entire ecosystem along the Sea of Cortez, especially the aggregation sites of El Bajo and Las Animas and provide economic opportunities for ecotourism. Through the involvement of local artisanal fishers in shark ecotourism, research, and surveillance near and around these formerly famous seamounts, we will allow the sharks to recover, and the health of the ecosystem will return along with the sharks.
Hot Spots of Diversity and Potential for Ecotourism
El Bajo de Espíritu Santo is an underwater mountain ridge thrust up from more than 1000 meters in depth up to shallow waters (18 m) El Bajo seamount was a major hotspot of marine life and biodiversity in the Gulf of California. An area so amazingly full of sharks, giant mantas, yellowfin tuna and other pelagic fishes that it became famous worldwide. It was considered one of the best places in the world to dive with schools of hundreds of hammerhead sharks in the late 1980s. But since then, the abundance of hammerheads and many other species of sharks have plummeted along their entire range in the Sea of Cortez due to intense overfishing. Also lost was a significant source of income by divers and photographers willing to pay to dive with sharks.
Engaging Communities to Stop Fishing Hammerhead Sharks
Pelagios Kakunja and the team have discovered areas where hammerhead sharks are pupping, and with the help from local fishermen, the team is tagging and tracking juvenile sharks. To allow hammerhead sharks to recover, shark fishing must be eliminated along the pathway between the nursery areas and the feeding areas along which the shark migrate. Along this proposed protected zone we are building relationships and gathering information from local fishermen and other stakeholders to support this new area protecting migratory sharks from fishing.
Switching from shark fishing to ecotourism-Recovery of economic loss
At the island of El Pardito, located midway between La Paz and Loreto near the island of Franciscito, fishers stopped fishing sharks four years ago and put away their shark fishing equipment. They have done this despite a loss of 40% of their income, that is, shark fishing represented nearly half of their gross revenue. This proud community of venerable fishermen from the Cuevas family are also ardent conservationists protecting one of the healthiest reefs with beautiful fish near their island. They currently fish for other species, particularly grouper, snapper, and other deep-water bony fishes. However, the economic loss of the fishers needs to be regained by carrying out other economic activities like shark research and ecotourism. Pelagios Kakunjá is already helping fishers by hiring them seasonally for research field trips, but this is not enough. Widespread support for this protected area by recreational and artisinal fishermen is critical to protect these sharks and allow them to recover.
Overarching goal of the project:
We aim to help recover the shark populations from collapse and near ecological extinction at the seamounts and migratory pathway connecting the protected area of Cabo Pulmo to the pupping areas off Loreto. To accomplish this goal, shark research and surveillance involving local artisanal fishers will help identify nursery sites and areas to protect mature females. Developing stakeholder and community support for the project is critical for success. Our team is meeting and conducting surveys among commercial fishermen, recreational fishermen, tourists and tour operators to better understand the social, ecological and economic benefits of protecting these and other sharks.
The most effective way to ensure a regular and sustainable income is via shark ecotourism. The core of our project is to help the fishers buy a registered panga and start an ecotourism activity during the months with most sightings of hammerhead and silky sharks in the area. This can be a complementary economic activity that could offset their loss in income.
This project is being directly implemented with the fishing communities along the migratory corridors. This community uses traditional hook and line, a highly sustainable and selective fishing method to catch grouper and snapper in deep waters off El Bajo. However, the La Partida fishers are truly concerned by the destruction of El Bajo as it is one of their main fishing grounds. They used to fish for sharks until a few years ago, representing a significant part of their income, but by witnessing the collapse of shark populations and getting involved in research and conservation, they now want to have a more active role in the recovery of hammerheads and sharks of once popular dive destinations such as El Bajo. Using this example, other fishing communities along the corridor are being consulted and interviewed along with other stakeholders to build knowledge, perspectives and support for the protected corridor.
Sharks Most at Risk
Like other species of large shark, scalloped hammerhead sharks, are more vulnerable to extinction than most marine vertebrates. With late onset of reproductive maturity, these sharks produce few offspring, have long gestation periods and are slow growing, making them vulnerable to overfishing. As has been experienced, their schooling behavior, migration through open waters and aggregation at pinnacles make these sharks highly vulnerable to targeted fishing. According to the IUCN Red List of Threatened Species, scalloped hammerhead sharks are critically endangered globally. The sharks are coveted for their large fins, which are used in shark fin soup.
Shark Stewards has joined Pelagios Kakunja to develop this protected migratory swim-way that connects critical nursery and aggregation areas like Las Animas along the eastern Baja peninsula. We are also working with local communities and artisanal shark fishermen to develop sustainable ecotourism between Cabo Pulmo and Loreto to support a no-fishing zone, and allow endangered hammerhead sharks to recover.
Despite the cascade collapse among shark populations, it is again possible to see a few juvenile hammerhead sharks at El Bajo for the first time in 20 years. Thus, the recovery of this incredible ecosystem is still possible, but to help the seamounts to fully recuperate we need to take immediate action to protect and conserve the shark populations and the entire pelagic ecosystem of El Bajo and nearby seamounts.
Project supported by the Ignite Foundation, and your donations.
