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/
Solomon Islands
During mid October to early November 2024, Seahawk’s mission continued to the Solomon Islands where we spent 3 weeks exploring this beautiful tropical archipelago.
The striking thing about cruising these islands is that on one level they look and feel very unspoiled, untouched and stunning but this first impression belies the islands turbulent past and the onslaught of relatively recent misguided economic policies.
Scratching beneath the surface you are soon aware of past events, most notably the indelible footprint and scars on the land and seascape of WW2.
One of the most infamous battles of WW2 between the allies, primarily the United States, and Japan took place at Guadalcanal in the waters famously called “Iron bottom Sound”. This name refers to the huge numbers of aircraft and ships lost during the battles in this stretch of water. Reportedly some 111 shipwrecks and 1,450 airplanes are at the bottom of this sound. One striking statistic is that many of the wrecks along the shore are Japanese vessels. This was because at the time the Japanese were under considerable pressure from the allies with much disruption to their supply lines and army presence. To preserve life and as many of their supplies as possible, should a ship be hit and at risk of sinking, the Japanese sailors would literally drive their ship aground to salvage what they could.
The many wrecks in this area and other locations around the islands provide rich pickings as far as interesting dive sights today.
Beyond the “man made’ dive sites, the Solomons offer rich and beautiful coral dive spots populated with a multitude of reef fish and other creatures. These all look very healthy and are thriving.
Sadly however, there is a notable lack of larger pelagic fish in this area. Misguided economic policies have allowed large commercial factory fishing vessels to operate along the near coastal areas of the Solomons that are wiping out large populations of the larger fish stock either by design or through the inevitable destructive and indiscriminate “by catch” that is associated with the use of miles of large nets.
The other devasting destruction the Solomon Islands have experienced in the past was the logging of huge areas of the old forests. This commercial activity left large areas of unvegetated ground that was then eroded by the regular tropical downpours of rain this area experiences. The knock on effect of this led to soil run off into the surrounding waters that stifled and killed off coral reefs.
Thankfully this activity has now stopped, the vegetation is recovering rapidly and notable improvement to once devastated coral reefs is being observed in a relatively short time period.
During our stay, Seahawk partnered up with local conservationists to help lobby to establish an MPA ( Marine Protection Area) in the Munda province. A meeting was held onboard Seahawk with local politicians and key community leaders to discuss and agree a Memorandum of Agreement to establish an MPA.
The Munda MPA area is a beautiful area that needs protection from indiscriminate fishing. The hope is to show the importance of conservation and how marine life will thrive if protected. The meeting onboard was regarded as a great success with the community leaders and politicians present agreeing to and signing the Memorandum of Agreement to establish the MPA.
Touristically, the Solomon Islands are relatively untouched but one of the islands greatest assets is their marine life and environment. Protect this and they will protect a sustainable source of economic activity that will be good for both the islands ecosystem and their population if managed well.
Mass overfishing and deforestation is not sustainable but sadly the politicians of the islands have gone down this route in the past and continue to do so. By helping to try and establish an MPA we hope to have helped move the needle just a little in the right direction and maybe, just maybe, helped shift political thinking into a more sustainable and brighter future for the islands.
One insight I took away from these beautiful islands is that a large percentage of the local population live in small, disconnected villages on the numerous islands in the Solomons. We were fortunate enough to visit and interact with the local people in various villages. Among their numbers were many skilled artisans who produced amazing wood carvings of local culture and marine life. All onboard Seahawk came away with stunning souvenirs of their visit to these wonderful islands.
I felt that although the villagers led a life of simple subsistence living, they all seemed happy, content and living at one with their environment. Although their lives are physically hard in comparison to so many of us they already seem to have what many of us aspire to have that is sometimes missing from our, arguably, over complicated lives.
Written by: Guy Hayward
Bad Romance – Shark Canyon
The south pass of Fakarava Island atoll, Passe Tumakohua, provides for one of the best examples of natural marine habitat facilitated by the exchange of seawater with slightly fresher water from inside a lagoon. It is the freshwater runoff (rain) that carves a path through the coral. (Corals cannot tolerate fresh water.) But beyond the formation curiosity, these passes are where the action is. The tidal currents that form both in and out of the lagoon 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.
While there are many fish species to behold, this place hosts an amazing density of gray reef sharks. Further, these animals are largely oblivious to the presence of divers. So, an up-close view is possible most days. Important to note, the danger from the gray reef sharks and most shark animals is minimal. To the extent there are attacks on humans the incidents are rare, usually caused by the shark confusing a human swimmer/surfer with normal prey during feeding times. Certain sounds including those similar to crushing an empty plastic water bottle can trigger aggressive behavior, too. Still, more people die from eating hots dogs than shark attacks.
Written by: Adam Alpert
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.