French Polynesia – Mystery of the Atoll Passes
A fascinating explanation about ocean tides and currents and how they affect the marine life in the remote atolls in the Tuamotu islands.
Video by: Adam Alpert
Indonesia – Walking Sharks
Walking Sharks and the Fight for Ocean Biodiversity in Raja Ampat:
The global abundance of oceanic sharks and rays has plummeted by nearly three-quarters (71%) over the past 50 years, primarily due to overfishing A quarter of all shark species are currently at risk of extinction.
Each year, approximately 100 million sharks are killed globally, either intentionally for their fins, meat, oil, and cartilage, or unintentionally as by-catch of the fishing industry. In stark contrast, sharks are responsible for just five to six human fatalities annually. Statistically, in the US you’re over 7 times more likely to die from eating a hot dog than from a shark attack
What We Saw on the Way to Indonesia:
Most people will never witness what we saw while navigating toward Indonesia: a forest of fishing vessels appearing on AIS (Automatic Identification System—a marine navigation tool) choking and overexploiting marine life. Seahawk was forced to weave and meander between countless boats and avoid hundreds of miles of fishing nets stretching across the ocean.
Overfishing of this scale has undoubtedly taken a toll on Indonesia’s marine biodiversity. Even in areas where coral reefs looked healthy, our dives revealed fewer large fish. A stark reminder of the invisible damage taking place. Demand fuels destruction, and the myth of “sustainable fishing” unravels quickly when faced with the reality of indiscriminate netting. These massive nets scoop up all species (known as by-catch), destroy habitats, and operate under poor regulation.
Change will only come when consumers reject these destructive practices. Among the countless vessels we passed a Singapore-flagged 250-meter bulk carrier ironically named Eternal Resource (insert eye roll here).
Raja Ampat’s Secret Shark:
One of the ocean’s lesser-known yet fascinating shark species is the Epaulette Shark (Hemiscyllium freycineti) also known as the “walking shark.” Endemic to the coral-rich waters of Raja Ampat, this shark is not your typical apex predator. It grows only about 60 to 76 cm (24 to 30 inches) long and has the unique ability to “walk” across the seafloor using its pectoral and pelvic fins.
These nocturnal creatures favour shallow reef environments, seagrass beds, and coral flats. Emerging under cover of night, they feed on small invertebrates like molluscs and crustaceans. They reproduce by laying eggs, typically placing them in rock crevices or coral outcroppings for protection until hatching.
Science at Sea: A Collaborative Mission:
To better understand and protect this unique species, Seahawk colaborated with Yacht Aid Global to support Indonesian marine scientists from the Elasmobranch Institute of Indonesia. Dr. Edy Setyawan, Dr. Danang Ambar Prabowo, Abdy Hasan and their team, have been conducting a groundbreaking study in Raja Ampat. Their efforts include tagging and tracking walking sharks to establish a population baseline and understand movement patterns.
Their research revealed highly restricted ranges for the sharks and a reliance on specific habitat types, making them particularly vulnerable to threats like:
· Artisanal fishing
· Habitat loss from coastal development
· Climate change and coral bleaching
Armed with this data, the team aims to implement local conservation strategies to ensure the long-term survival of the species.
Innovative Conservation: eDNA and Biologging
The research team is also pioneering the use of environmental DNA (eDNA) to detect the presence of walking sharks through water samples – an innovative, non-invasive method that allows scientists to track species even in hard-to-reach habitats.
In tandem, biologgers are being deployed to gather data on temperature and depth preferences, helping scientists understand how the species may adapt, or struggle, in response to climate variability.
These combined methods are offering a richer, more accurate picture of the species’ life cycle and habitat needs, contributing to science-based policy and management decisions.
Why Should We Care About a Walking Shark?
It’s easy to dismiss the plight of a small, strange-looking shark as inconsequential in the grand scheme of ocean conservation. But the truth is: we don’t fully understand the ecological role of many marine species until their absence causes cascading, devastating effects.
Just as a skyscraper depends on hidden structural supports, our oceans rely on species big and small. Remove enough, and the whole system begins to crumble. Biodiversity is not a luxury, it’s the foundation of ocean health.
The story of the walking shark is more than a curiosity, it’s a call to action. In Raja Ampat, where marine life clings to fragile reef systems, the survival of this small, remarkable species reflects the health of the broader ocean. Through cutting-edge science and cross-border collaboration, we have a rare opportunity to protect not just a single shark, but an entire ecosystem. The choices we make, what we eat, how we travel, what we support, ripple outwards. If we want thriving oceans tomorrow, we must act today – with awareness, intention, and a deep respect for even the smallest creatures that “walk” the seafloor.
Article written by Nicola Watton
Sources:
Marine Megafauna Foundation
Rodolphe Holler – Tahiti Private Expeditions
For more information, visit:
https://yachtaidglobal.org/campaigns/operation-swimway
https://www.elasmobranchinstitute.id/
French Polynesia – Operation Swimway
Much of what the S/Y Seahawk mission is about involves developing a better understanding of the marine environment, especially pelagic species. The focus is on migration patterns, Tiger and Grey Reef sharks of special interest because it is suspected that the travel itineraries in play are key to sustainability. Understanding reproduction strategies for these animals is also important. Knowing where the pupping areas are located could be the key to protecting the threatened population without having to make the sometimes-controversial Marine Protection Areas (MPAs) excessively large. For this, we mostly lean on our visiting scientists including Clémentine Séguigne who joined S/Y Seahawk for its most recent exploration of the Tuamotu Islands, French Polynesia during the months of March and April. The work itself is awe inspiring just because of the magnificence the laboratory affords. Of course, the science that follows is exceedingly important, too. What is learned may be the key to not only saving a species but the ecosystem as a whole.
The Tuamotu Island chain of French Polynesia is known for its stunning beauty both below and above the water. There is much complexity here to unravel because these atolls all revert to a volcanic history. Similar to the present-day younger islands of Moorea and Bora Bora, the Tuamotu islands once enjoyed some relief. Now, where there was land forming, e.g., domes and plateaus, there are luxurious lagoons, in most cases surrounded by the remanence of vast coral colonies. There are also one or more natural passes that exit these lagoons. In some cases, the passes through the coral reefs were formed because of the geology in play. More often it is the freshwater runoff (rain) that carves a path through the coral, (coral does not like fresh water.) But beyond the formation curiosity, these passes are where the action is. The currents that form both in and out of the lagoons attract a wide variety of species. Some come to these places to breed. Others, prototypically a variety of shark species, enjoy feeding and the luxury of resting on the bottom while the current effortlessly pumps oxygen through their gills.
Sharks are a keystone species in the marine ecosystem. As an apex predator, they keep the ecosystem in balance, and without them, the entire food web will collapse. Sharks are vital to the health of the oceans and to our existence on this planet. We must protect them.
Seahawk is on a mission to help researchers and advance the protection of sharks. In 2021 we began our involvement with Operation Swimway and partnered with researchers to tag 4 Tiger sharks and deploy 10 electronic receivers underwater to detect the transmission of the tagged sharks. Each receiver is an electronic device capable of detecting acoustic signals from the tags; it is encased in a waterproof canister that is about the size of a 1 litre water bottle, and affixed to the ocean floor by a rope attached to a chain at the base and a buoy at the top to keep it upright in the water column. To learn more about this endeavour, check out our mission log from our last trip in 2022 to French Polynesia.
Fast forward 2 years and Seahawk is back cruising around the stunning Tuamotu Islands, French Polynesia in March 2024. Along with our excellent guides Rodolphe and Sébastien, Tahiti Private Expeditions, the dive team followed the GPS coordinates of the receivers and set out to retrieve them. The team strategically planned each dive to navigate strong currents, shifting tides, and depths up to 35 meters to dismantle the chains, buoys, and collect the receivers with 2 years of crucial data about the sharks’ movements.
After the retrieval mission was complete, Seahawk sailed back to Tahiti and returned the canisters to the research team at IREMP so that they could analyse the sharks’ movements over the past 2 years. They learned some fascinating information about the local tiger sharks, which atolls they tend to prefer, which ones they didn’t visit, and which passes they frequented. Because of this information learned, the research team decided to focus their next data collecting mission on one unique atoll called Tahania atoll. This spot was chosen because tiger shark activity was detected here, and it is uncommon for an atoll to have 3 separate passes that allow water and marine life to flow in and out of the lagoon with each changing tide.
Along with researcher Clémentine Séguigne, and our experienced local guides, Seahawk helped deploy 6 new receivers at Tahania atoll. The receivers were strategically placed on the outside corners of each of the 3 passes to get the best chance of detecting a ping from a tagged tiger shark. Clementine found that the best chance for data collection would be at a deeper depth, so we deployed each receiver at a depth of 30-40 meters. The team had to work quickly at these depths and pay careful consideration to their no decompression time limits, but once the receiver was successfully installed, and the GPS coordinate marked, there were high fives and celebration all around! We look forward to learning more about the tiger shark movements around Tahania Atoll.
Through all these efforts, the ultimate goal is to better understand the tiger shark movements and ecology so that the researchers can propose MPAs to the local government and protect the crucial habitats for the species. Seahawk is one vessel able to provide support to researchers conducting field work in these remote locations. Through nonprofits like Yacht Aid Global, the hope is that other vessels will become involved in similar projects, all part of the greater effort to preserve the world’s oceans.
Galapagos – A Science Trip to Darwin and Wolf
Seahawk arrived to Darwin in July 2021, the northernmost island in the Galapagos archipelago, after previously cruising the southern parts of the province and formally launching YachtAid Global’s Swimming and Sailing program in San Cristobal.
Much excitement could be felt on the boat as the inaugural science mission was about to begin. In a joint effort led by YachtAid Global, Seahawk became an active participant in Operation Swimway; a project dedicated to lending support to science and marine conservation NGOs conducting state-of-the-art research around the world.
Operation Swimway’s focus is to determine patterns of migratory animals, such as sharks, mantas, and turtles. Understanding the movements of these animals and the corridors they use to feed and breed is key for protecting all marine life, especially so for sharks who have to take increasingly dangerous journeys due to unsustainable fishing practices and other hazards including water pollution. High on the list of Operation Swimway’s priorities is to precisely define endangered species migratory patterns. The data collected and analyzed is then used to help define candidate Marine Protected Areas (MPAs) with the goal of seeking and obtaining approval from the responsible governing agencies.
While visiting Darwin, Seahawk was joined by scientists from the conservation group Migramar, a well-known organization that operates in the Eastern Pacific Ocean dedicated to studying the movement of threatened marine species. Dr. Alex Hearn led the effort on this expedition, which focused on studying whale sharks, known to visit Darwin Island during the July, August, and September timeframe. Adult female whale sharks congregate annually in the Galapagos, a phenomenon that is one of the subjects of Migramar’s research. Most of the females are pregnant when visiting the islands, suggesting the archipelago could serve as a nursery for these sharks. The mission’s objective was to attach GPS tags to individual whale sharks in order to provide tracking data based on a representative sample for determining the overall nature of species’ movements. Very little is known about where the whale sharks go, their pupping grounds, or their feeding habits.
During our cruising of Darwin and Wolf, we were lucky to have several encounters with some of the whale sharks. As stewardess Thea remembers:make
“It was a crazy experience. I suddenly saw this 12-meter fish swimming very fast past us. You could feel the water moving around you as she swam past. The scientists tried to tag her, but failed to do so as she was at full speed. The sighting lasted a few seconds, but it was incredible.”
Some of the attempts at tagging these sharks were successful, but the process is far from perfect. The sheer size, speed, and strength of whale sharks make the attachment of transmitters very challenging.
But not all was focused on GPS tracking. Dr. Diana Alexandra Pazmiño Jaramillo was part of the science team leading Operation Swimway. Her work at the Galapagos Science Center focuses on a more evolutionary approach; research designed to trace the migration patterns of various shark genotypes by using genomics, a special kind of DNA fingerprinting used to identify individual species without actually tagging them. Dr. Diana Alexandra’s work involves analyzing the secretions and tissues of the animals at a molecular level, which is crucial to revealing their behavior and patterns of movement.
Miguel Herrero, Marine Biologist and Project director at Mantas Ecuador, was also on board Seahawk. His research revolves around developing an understanding of both the reproductive processes and migration patterns of giant manta rays. But Miguel is also interested in the role of cleaning stations and the special fishes that symbiotically bond to keep the rays healthy and free of parasites. Like many symbiotic relationships in the ocean, there is much specialization. In the case of the giant mantas, there are only a few specific types of cleaning fish suitable for servicing this shark family species.
During our days at Darwin and Wolf, owners, guests, and crew were fortunate to experience the outstanding marine life that the famous Galapagos islands hold, while also witnessing how research on marine animals is conducted by professional scientists; an inspiring and educational experience.
However, not all was fieldwork. The Seahawk team also attended presentations held by the Migramar scientists, in which they discussed the experimental design needed to further improve the understanding of the mechanisms in play. Much was about how to better track the animals, sharks and mantas, but also important to the cause was developing a comprehensive understanding of the ecosystem; the Galapagos islands in particular are complicated because of the byzantine matrix of converging currents, some very warm, some very cold. It is acknowledged that a more holistic approach to science is likely the right answer in order to secure the outcome desired.
Prototypically, developing MPAs in isolation will not solve the problem unless other environmental hazards are addressed. Migramar and other similar NGOs realize the problem is multifaceted and are working to establish more comprehensive understandings and solutions. As for the Seahawk team, the boat is exceedingly proud to have played a small role in this most important effort.
If you’d like to know more, you can watch the video below. It includes interviews with the Migramar team on board, as well as footage of our days cruising the islands. Not to be missed!
Fiji, Part II – Lau and the Seascape Initiative Project
While our exploration of Fiji during the first part of the trip delivered much to celebrate, not all is well in paradise. In particular, underwater exploration of Fiji revealed much stress on the coral and fish life there; a bittersweet realization given the many goodnesses characteristic of the country. Arriving within the Lau Group, Fiji’s least visited hidden jewel to the east, we hoped to find a natural world largely untouched.
It is now August, about half way through our Fijian itinerary. Here, in Vanua Balavu, Seahawk and her crew stood ready to support a new scientific mission, again organized by our partners at YachtAid Global. This is where the sponsored scientist, Kristian Miles, working with the NGO Conservation International (CI), joined us to survey the remote islet of Duff Reef, a recently declared turtle sanctuary.
Sadly, many of our dives, including those conducted with Kristian, showed the coral reefs were struggling. Many colonies were bleached or suffering from other stressors such as cyanobacteria blooms and destruction by cyclones. And other marine life, especially larger pelagic fish species, were suspiciously lacking,
All signs point to what is now a common problem around the world; overfishing, bad agricultural practices, and climate change. Over the course of our trip, we learned about Fiji’s struggles with overfishing, unsustainable fishing practices (catching of undersized, juvenile fish), and a growing population that increasingly turns to the sea for subsistence. Recent cyclones to hit the islands have also been problematic, some causing serious damage across coral reefs and devastation on land.
We wanted to know more about Fiji’s underwater world, the challenges faced and the organizations and individuals working towards solving them.
Behind the recently protected Duff Reef was the Lau Seascape Initiative; a plan launched in 2019 to protect Lau’s marine and terrestrial life from the current challenges while preparing the region’s communities to develop sustainably. It was launched by regional leaders with Conservation International and partners, with the support of the Fijian government.
Duff reef is a community-based marine managed area and is now a no-take zone where sea turtles can find refuge as they visit the site to breed.
The mission was going to be highly constructive. Kris gave the crew and owners a presentation explaining the Duff Reef environment and the many species found there. The introduction was fortuitous because it facilitated both owners and crew playing a role in surveying the area for key species of marine life. Much to take in and learn to be able to properly identify the different turtles species and other resident fish like groupers, jacks, and barracuda targeted for the survey. It was an intensive course that had some of the team members studying the fish identification book all night prior to next day’s planned dive.
Unfortunately, due to rough weather conditions that included 40-knot winds and heavy rains, Duff Reef’s expedition had to be canceled; located in a very exposed area (the islet is a small sandbank in the ocean) and surrounded by coral reefs, the risk of dragging anchor in such a delicate environment was too high. Seahawk got there and had to turn around straight away, back to the sheltered waters of the Bay of Islands.
On the bright side, Kristian and the Seahawk team were able to deploy a remote underwater temperature monitoring system in the northwestern pass of Vanua Balavu, to collect data on the inputs of ocean temperature. This unit is part of a greater effort by the University of the South Pacific to understand the impacts of climate change. The device will record temperatures over short intervals for up to a year. The annual retrieval/replacement of these devices will aid in the collection of data on ocean sea temperature changes. A similar system has already been installed in the southern Lau Group reef system.
During the days Kris was with us he was able to conduct several surveys of marine life in the various Vanua Balavu passes Seahawk visited. These surveys are about determining the density of populations of benthopelagic and pelagic animals along with turtles & sharks within scientifically important areas of the Lau group.
The dive sites we explored were some of the best of the trip. The reefs were healthy, like busy cities, filled with fish, and diving alongside the reef wall we encountered big schools of barracuda and other pelagic fish. A thriving environment that benefits from the remote nature of the region.
Still, cyanobacteria blooms were also present there. As Valu and Kris showed us how to identify the red algae covering the reef, it was difficult to unsee it. Another sign of how nutrient runoffs from agriculture are having an impact everywhere.
It is hoped that the Lau Seascape Initiative accomplishes its conservation goals and that the dependent communities in the area enjoy a sustainable future. There is much damage done, but also a lot to be saved within the pristine waters of the Lau islands.
The weeks that followed in Lau were marked by an immersion into the Fijian culture and a deeper understanding of the way of life and traditions of Fiji, as Seahawk made her way south of the group and visited some of the country’s most remote corners.
References used on this blog:
Sheldon Chanel, Shailendra Singh (2021, February 3rd). Fishing in Fiji Under Strain [Blog post]. Retrieved from https://earthjournalism.net/stories/fishing-in-fiji-under-strain#:~:text=According%20to%20a%202009%20University,fishing%20practices%2C%22%20says%20Dr.
Andrew Freedman (2020, December 17th). Fierce Cyclone Yasa strikes Fiji as one of the country’s most powerful storms [Washington Post]. Retrieved from https://www.washingtonpost.com/weather/2020/12/17/cyclone-yasa-hits-fiji/
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.