Mexico – Operation Swimway in Cabo Pulmo and Revillagigedo

Mexico – Operation Swimway in Cabo Pulmo and Revillagigedo

The Revillagigedo archipelago was a blessing in disguise for Seahawk. The visit, courtesy of a mechanical problem, landed the yacht in Ensenada until well beyond the time when a safe, typhoon-free crossing to the South Pacific would be possible. While not part of the yacht’s original itinerary, a remarkable trip with outstanding diving and marine encounters was the result. Mostly, though, we are grateful for having the opportunity to collaborate with Pelagios Kakunja, a world-renowned marine conservation NGO, to better understand the migratory patterns of pelagic species including sharks. Sometimes good things happen when you go off course.

Pelagios Kakunja operates in Mexico studying the populations of sharks and mantas that inhabit its waters. Their goal is to provide research that helps implement conservation strategies for the different species of these territories, many of which are known for their rich biodiversity, but also under stress due to overfishing and other threatening anthropogenic practices. 

After a few days exploring the mesmerizing surroundings of La Paz, Baja California, we were joined by scientists James Ketchum (Co-Founder of Pelagios), Miguel Grau (Field Technician), and experienced fisherman Alejandro Romero. And so the expedition “Operation Swimway” began. The main objective was the installation of new acoustic receivers and BRUVS (Baited Remote Underwater Video System) in strategic areas, the maintenance of legacy receivers, and the tagging of additional sharks, whose fastened transmitters will provide data on behavior and migration patterns. 

The technology used by Pelagios has been a popular tool among experts studying the movements of migratory marine animals. In the case of Pelagios’s work, tagged sharks in the proximity of the receivers send signals that identify the individual animal and its time of encounter, along with several other parameters.

The data on this acoustical sensors is then accessed by retrieving the receivers from the strategically fixed locations where they’ve been installed, a process that is done after 18 months or more. With enough receivers and transmitters installed and working together, a map of the species’ movements can be created, revealing migration patterns in and across the MPAs (Marine Protected Areas).

The information gathered on Operation Swimway intends to further the research on migration patterns; critical information that will benefit the creation of protected corridors between the MPAs of the Gulf of California and the Mexican Pacific.  

As for the BRUVS, they are useful for collecting data near important areas such as cleaning stations. These cameras gather information on shark behavior, such as feeding patterns and reproduction, thereby facilitating a more comprehensive picture of species’ life function and relationship to the environment.

In the days we spent cruising the waters of Cabo Pulmo and Revillagigedo, Pelagios managed to install 1 new receiver in Cabo Pulmo, renew a total of 7, and tag 4 sharks (two sharks with acoustic transmitters and two with satellite ones).

The owners, guests, and crew on board Seahawk also had the opportunity to attend educational presentations made by James and Miguel, who taught us about the research being conducted in the present and how the receivers installed work to gather valuable data. We also learned about the different species of marine life encountered in the areas visited and their conservation status.

Our experience exploring the underwater world of the Sea of Cortez and the Mexican Pacific is a highlight on Seahawk’s journey. From bull sharks in Cabo Pulmo to schools of scalloped hammerheads in the islands of Revillagigedo, along with the many encounters with the oceanic manta rays, magnificent gentle giants with wing spans of up to 25 feet, we are in awe of what the marine world holds.

Sadly, though, evidence points to the decline of sharks and reef fish in the past 20 years around most of the areas we visited. Industrial and unregulated fishing is a concern and a constant threat for many of these species. Pelagic fish migrating long distances, away from the protected areas for mating or feeding, are a special worry.

There is cause for optimism, however. Increasingly, there are inspiring stories that suggest positive change is in the wind. Oftentimes, the local communities negatively affected a declining environment successfully advocate for change. Cabo Pulmo National Park, 50NM south of La Paz, is an MPA with thriving marine life. But it wasn’t long ago that the region’s coral reefs and aquatic life were on the brink of collapsing, due in majority to overfishing and pollution. As studies started to be conducted on the area and locals became aware of the damage, the community came together in an effort to make Cabo Pulmo a protected area. Today, the town has a sustainable business model based on ecotourism and enjoys a healthy underwater world that keeps on giving income; marine animals, such as the resident group of bull sharks that inhabit the region, are more valuable alive than dead. 

Seahawk’s expedition in Mexico represents an important milestone. It reflects an aspiration to actively contribute to reverse damage to the environment by leveraging science, education, and technology in concert with the local experts best equipped to guide the effort. We hope Seahawk’s participation in “Operation Swimway” with YachtAid Global and Pelagios Kakunja helps protect bigger areas and create more MPAs, while serving to push conservation efforts even further. At the very least, all those involved come away knowing that a world without sharks is a poorer world and one that is likely unsustainable.

French Polynesia, Part II: Supporting Research in the Tuamotus

French Polynesia, Part II: Supporting Research in the Tuamotus

We had been navigating the French Polynesian waters for 6 weeks before our new Operation Swimway began in the Tuamotus Archipelago. After visiting some of the remote Marquesas islands, cruising the pristine waters of the Western Society Islands, and experiencing the culture in Tahiti and Moorea, we were set to start the next science expedition on board Seahawk.

For this trip, we were joined by a team of renowned marine researchers from top universities in the U.S and France; Eric Clua, Ph.D., shark specialist and professor at Centre de Recherches Insulaires et Observatoire de l’Environnement (CRIOBE); Mark Royer, Ph.D., Shark expert from the University of Hawaii; and Clémentine Séguigne, shark ecologist and Ph.D. student at CRIOBE. Planning and logistics for this mission were also arranged with YachtAid Global and Carl Meyer, Ph.D., professor, and researcher at the University of Hawaii.

Rodolphe Holler, our local guide and videographer throughout our time in French Polynesia, and his assistant Tearenui Poole joined the trip with their boat ‘Coconut’. Rodolphe’s expertise and understanding of the area were key for a successful trip and a safe navigation through the different Atolls.

This time, the mission’s goal was to study tiger shark populations in some of the Atolls of the Tuamotus. Specifically, their migration patterns and habitat use across the archipelago.

The research focused on tiger sharks as there’s still a lot to learn from them within their Polynesian habitats. Existing studies in the country have shown a population predominantly female from sightings around shark ecotourism sites, with males being a minority and seen more often in pelagic environments. Although photo-id studies have shed light on females’ reproductive biology, more studies needed to be conducted to deepen the knowledge of sharks’ habitat use and behavior in the Polynesian waters.

The objective of the project conducted in the Tuamotus, therefore, was the tagging of several individuals, the installation of new acoustic receivers, and the recuperation of old ones to recover previous data.

Our expedition began in the atoll of Makemo, located in Central Tuamotus. From there, we started a 10-day trip that was action-packed, with an itinerary that incorporated some of the archipelago’s most remote corners, where we found ourselves looking for tiger sharks, diving the extreme passes of the atolls, and even swimming alongside the rare Chilean Devil Rays (Mobulas Tarapacanas) in Raroia, as Eric collected DNA from them.

Another interesting experience was joining the scientists in their “recovery dives”, where we would drop at a location where previous receivers had been placed, to grab them and place new ones. These dives were challenging at times, due to the receivers being broken off and swept away by the strong currents of the passes. Due to the COVID lockdowns, some of the receivers had been in place for 2 years or more. Finding them was always a reason for an underwater celebration.

Fortunately, the data collected from these older receivers was worth the long search, as it had very valuable information on some of the sharks’ long migrations across French Polynesia. To be precise, a particular individual often sighted in Tahiti was recorded to have traveled several times to Hao (900km away!), proving the shark’s long-distance journeys.

The trip also included a visit to a local school in Hao, where Eric gave a presentation to students, aged 10 to 16, and taught them about sharks and their importance within the ecosystems they inhabit. The goal of the presentation was to educate the young generations about sustainable fishing practices, and why it is important to keep sharks alive in order to keep reefs and fish populations healthy. It was inspiring to see the great interest the children showed, and how knowledgeable some of them were, as they come from families that heavily depend on fishing as a source of income.

As for the shark tagging, the science team managed to tag a total of 4 tiger sharks (3 of them in one day!); A remarkable accomplishment, considering that a total of 10 sharks had been tagged in 7 years. It was also an unforgettable experience for guests and crew on board, as most were able to be present during the tagging.

However, this trip also made us face a hard reality. During one of our dives, in Raroia, we came across a dead black tip reef shark that showed signs of stabbing. A gruesome sight that most likely indicated that it had been killed for being a nuisance to fishermen. There is still work to be done in educating the population about shark conservation. Unfortunately, that isn’t just a local concern, but an international one.

On a positive note, thanks to the researchers’ accomplishments during the trip, a broader picture of these sharks’ spatial movements across the different atolls and further islands such as Tahiti is now underway. Hopefully, the new data will provide meaningful insight to protect key areas that serve as mating and pupping grounds for these animals, as well as create protected corridors for them to travel across islands safely.