Whale Sharks

‘Bone Sharks’ are fun to swim with!

In wildness is the preservation of the world.{d}

Whale Sharks (Bone Sharks) visit St Helena every year from December to March, and you can swim with them!

About

Global range

We get annual visits from Whale Sharks rhincodon typus (local name: Bone Sharks) - the largest known extant fish species, averaging nearly 10m long and sometimes weighing around 20 tonnes (the average weight is 9 tonnes). These enormous and completely harmless{1} animals are stunning to watch. To get an idea of their size look at the comparison image (left)…

Although normally solitary creatures, at the end of January 2013 a group of 17 Whale Sharks were spotted around St Helena{2}, much to the delight of ecologists and tourists alike. They have come back in increasing numbers, every year since…

…and you can go out and swim with them!

Despite their size Whale Sharks eat only plankton, including copepods, krill, fish eggs and even baby squid or fish. To collect this prey they have an enormous mouth and some Whale Shark watchers are concerned that they might be swallowed, albeit accidentally. But as Dr. Alistair Dove, a leading Whale Shark expert, explains: Their mouth may be up to 1.5m wide, but their throat is not much bigger than a £1 coin, so they couldn’t swallow you even if they wanted to.{3}

Whale Sharks are officially classified as Endangered{e}. Recent research suggests they may live up to a century.

It is now thought that Whale Sharks may come to St Helena to breed. They arrive each year in almost equal numbers of males and females, and females in the early stages of pregnancy are sometimes observed here. Actual mating or pupping of Whale Sharks has never been observed anywhere in the world, but mating seems to be the best explanation for their annual visits to St Helena.

In 2021 the St Helena National Trust conducted a census on the Whale Sharks that visited that year, concluding that the total population around St Helena that year was 312 Whale Sharks. 21 were recorded here for the first time anywhere in the world. In 2023 a male and a female were observed displaying potential courtship behaviour - the closest to actual mating that had been observed anywhere in the world.

The local name for Whale Sharks is ‘Bone Sharks’. We have no idea why… don’t all sharks have bones?☺

Swimming with Whale Sharks

Whale Sharks are docile creatures and there is no record of one ever having attacked or attempted to attack a human. Indeed they will happily allow humans to ‘hitch a ride’, though this is prohibited because of potential disturbance to the animal (see Whale Shark Rules, below).

All the firms that offer Dolphin watching trips also offer Whale Shark trips. In addition the Dive Companies also offer both swimming-with and diving-with trips.

To protect the species the following ‘Whale Shark Rules’ were published regarding human interaction with Whale Sharks:

• Touching or riding Whale Sharks is strictly prohibited

• The use of flash for underwater photography is prohibited

• All persons to remain a minimum of 3m swimming distance away from the Whale Sharks

• Do not chase after a Whale Shark in an aggressive manner

I was alongside the Whale Sharks for over half an hour. It was an experience that will never leave me.{f}

St Helena has become my favourite place to encounter these gentle giants. Nowhere else have I seen so many large adult sharks in such a small area.{g}

St Helena Whale Shark Festival

On 22nd February 2019 the St Helena National Trust held a ‘Whale Shark Festival’ at The Mule Yard, which included a virtual-reality Whale Shark ‘experience’. The event was repeated in subsequent years and it is thought the event will continue in future years.

International Whale Shark Day

Apparently celebrated on 30th August. We didn’t think this was a real day (Wikipedia didn’t mention it) and the only sites that did (e.g. daysoftheyear.com) are somewhat suspect - we think they make up ‘days’ just to get clicks - but in 2022 the St Helena National Trust made a Social Media post Happy Whale Shark Day, and if they are celebrating it then it must be real!☺

Unfortunately (for St Helena) the Whale Sharks are not here in August, which is why the St Helena National Trust-organised Whale Shark Festival takes place in February (when they are).

One to take home?

The Art & Crafts Association Shop usually has some knitted Whale Sharks and various other Whale Shark related gifts & souvenirs - all considerably smaller than the real thing and able to fit in a suitcase…

In 2023 Solomons, as part of its campaign the reduce plastic use, stopped issuing plastic bags to its shop customers. Instead it had re-useable canvas shopping bags printed, featuring (initially) The Wirebird and Whale Sharks. See the example of these bags (right) and read this article.

Read More

Below: Whale Sharks Watch Article: Whale Sharks may live up to a century, Cold War bomb dating reveals Article: I Sailed Twenty Thousand Miles to Swim With Whale Sharks Article: World’s Largest Fish and One Tiny Island: Studying Whale Sharks on St Helena Island Article: Durban ‘Environmental Disaster’ Reaches St Helena

Whale Sharks Watch

See whalesharkwatch.org.

Article: Whale Sharks may live up to a century, Cold War bomb dating reveals

By Liz Langley, nationalgeographic.com, 6th April 2020{4}

Whale Shark Rhincodon typus
TYPE:	Fish
DIET:	Carnivore
GROUP NAME:	School
AVERAGE LIFESPAN IN THE WILD:	70 years
SIZE:	5.5m to 10m
WEIGHT:	20 Tonnes
POPULATION TREND:	Decreasing
IUCN RED LIST STATUS:	Endangered

Beautifully patterned with white spots and stripes, the 5.5m to 10m long Whale Shark is the largest - and one of the most striking - fish in the sea. Though it’s beloved by ecotourists and native to temperate oceans the world over, very little is known about these behemoths - including how long they live.

Recent investigations into other shark species have revealed astounding life-spans: The Greenland shark, for example, can live nearly 300 years, longer than any other vertebrate on Earth. (Many more sharks, such as the great white, near the 100-year mark.)

Those discoveries are largely because of advanced methods for determining a shark’s age, such as tracing carbon-14, a rare type of radioactive isotope that is a by-product of Cold War-era bomb detonations, in shark skeletons. Measuring amounts of this element can tell scientists a shark’s age more accurately than the previous approach, counting tree-like growth rings on Whale Shark vertebrae. That’s because how much time each ring represents has long been a subject of dispute.

Now, researchers using radiocarbon dating have identified the remains of a Whale Shark that lived 50 years, the most ever for that species, says study leader Mark Meekan, a fish biologist at the Australian Institute of Marine Science.

He adds that it seems possible that these really big sharks could live to be about a hundred years old.

Meekan says his study, published April 6th in the journal Frontiers in Marine Science, is crucial to the conservation of these endangered species.

That’s because the Whale Shark’s longevity makes the species as a whole more vulnerable to threats such as legal and illegal fishing, warming ocean temperatures, and ship strikes.

Bomb analysis

From 1955 to 1963, atomic bomb testing in the United States and other countries doubled the amount of carbon-14 naturally in Earth’s atmosphere. That excess was absorbed into the ocean and taken up by everything in the food web - including cartilaginous Whale Shark skeletons.

By comparing the amount of carbon-14 in the oceans during certain years with the amount of the isotope captured in successive vertebral growth bands, the researchers could discern a shark’s age.

Basically what we showed is we have a time stamp within the vertebrae. We count the bands from there, and they appear to be annual, Meekan says.

Meekan and colleagues took vertebral samples from two shark skeletons, one that had been caught legally in a Taiwanese fishery in 2005 that had 35 growth bands; and another from an animal that was stranded off Pakistan in 2012. That one had 50 growth bands.

Because the 50-year-old Pakistan shark was only 10m long, and the animals can grow to double that size, bigger Whale Sharks undoubtedly are older than the two tested, he says.

‘Real data from real animals’

This study is really important because it gets rid of some of those questions about the age and growth patterns of Whale Sharks, says Taylor Chapple, a research scientist specializing in sharks at Oregon State University.

Conservationists need to know the growth rate of a species, he says, because a slower-growing species is more susceptible to extinction than one that reproduces quickly. The Whale Shark’s global population has fallen by more than half over the past 75 years, according to the International Union for Conservation of Nature.

Having real data from real animals, he says, adds a really a critical piece of information to how we globally manage Whale Sharks, for example by trying to minimize Whale Sharks caught accidentally while fishing other animals, which is known as bycatch.

Beyond being a vital part of the ocean ecosystem, Whale Sharks also support the ecotourism industry, which in many places offers opportunities to see or snorkel at a safe distance from the animals. In some locations, however, such as in Oslob, Philippines, shark-watching is controversial because of the practice of feeding or getting close to the animals.

Ecotourism keeps a lot of people out of poverty in many developing countries around the world, in particular in Southeast Asia, Meekan says.

We have a responsibility not just to the sharks, but also to those communities to make sure they’ve got a future.

Liz Langley is the founding writer of National Geographic’s Weird Animal Question of the Week.

Article: I Sailed Twenty Thousand Miles to Swim With Whale Sharks

By Matt Ray, published on medium.com, 30th January 2020{4}

The first time I thought about swimming with Whale Sharks was in Roatan, Honduras, in 2016. I had been there for a week but had just left my job as a computer consultant and had an extra week to blow in Honduras. I booked a boat to Utila, an island about 30 miles from Roatan, where I heard there was at least one Whale Shark. I could hardly wait to get there! There was a Whale Shark diving organization going there the same day so I was in good company.

I booked a week of diving (2 boat dives per day) at one of the local dive schools and found a place to stay nearby. Utila is a cool little island with lots of dive shops and some very interesting things to see. I rented an enduro motorcycle all week and explored the island from one end to the other.

It was hot in Utila and after two attempts I found the right accommodations with an adequate fan. Every morning I showed up at the dive shop and they promised if we saw Whale Sharks, they would immediately stop and let us swim with them. You aren’t allowed to swim with Whale Sharks using scuba gear; only fins, snorkel and mask. I went every day for three days and then on Thursday morning, I woke up with some serious sinus congestion and had to cancel my dives for that day. You can’t really clear your ears and dive effectively with sinus issues.

Guess which day they saw the Whale Shark? Thursday afternoon I checked in with the dive shop and they saw a shark that morning and everybody got to swim with it. I was so discouraged, not only because I was sick in a place where I had come to dive, but because I had missed the Whale Shark! I didn’t recover enough to dive again until I was leaving the island and returning to the US.

Search for Whale Sharks Begins

I went home and within a month I decided to take a break from my computer consulting business and instead pursue a dream of mine to sail around the world. A month later I was heading to Spain to get my Yacht Master Certificate and then start sailing around the world, by Global Hitch-Hiking or crewing. I sailed with one boat from Virginia to Aruba, then took a plane to Bonaire, where I earned my Dive Master Certificate. Two months later I flew to Panama and joined a boat sailing to Tahiti. From Tahiti, on yet another boat I sailed through Bora Bora, Niue, and Tonga. In Tonga, I joined my last boat for the year and we sailed to Malaysia.

On the boat to Malaysia, my skipper was a diver and he knew a great place to see Whale Sharks in Indonesia. I was out of my mind with excitement! We sailed outside of our planned itinerary to go down to the Whale Shark location, a large bay with 20-30 fishing platforms. The Whale Sharks love to hang out underneath fishing platforms because the nets hang down into the water and often smaller fish and sea life swarm underneath them. Whale Sharks eat plankton, krill, and fish eggs, among other things, and these fishing platforms tend to attract these items in abundance.

Unfortunately, we struck out. We had sailed into the far end of the inlet the night before and woke up early the next morning, motoring from fishing platform to fishing platform, asking if they had seen any Whale Sharks that day. None of them had. After a few hours of trying, we finally gave up and went back to our normal itinerary, heading to Kuala Lumpur. That was August of 2017.

Two More Oceans, Still No Sharks

To finish out 2017, I stayed in Kuala Lumpur and travelled around South East Asia, but didn’t do any diving, other than some free-diving in the Gili Islands. In May of 2018, I boarded a 40-foot boat in Darwin, Australia, and sailed it with the owner across the Indian Ocean, arriving in Cape Town, South Africa in December 2018. We made many stops along the way, saw plenty of whales and dolphins, but didn’t see any Whale Sharks.

In February of 2019, we left Namibia, sailed for two weeks, and arrived in Jamestown, St Helena. Jamestown is a quaint island, a British protectorate, and is famous for being where Napoleon was sentenced to spend the rest of his life after he was captured by the British{5}. A truly lovely place to visit, and one of many places I travelled to that I had never heard of before sailing there.

While we were there, we were told about several shivers of Whale Sharks that swam in the waters of the island, sometimes up to 25 in number. There was actually a Whale Shark symposium going on while we were there, so we got quite a lot of information about them.

We scheduled a tour for the following day, but that morning it was cancelled because the swells were too big. Murphy’s Law was really playing with my head at this point. 20,000 miles of sailing, hoping to swim with Whale Sharks and once again, I’m being thwarted! Please don’t let this be yet another near miss. We rescheduled for the next morning. We checked in with the tour group and they said that they couldn’t do it that morning for some reason but rescheduled again for 2pm that same day. Of course, in my mind, I kept thinking it was going to be cancelled or rescheduled again, as is my luck with Whale Sharks.

Yes! Finally, Whale Sharks!

At 2pm we boarded the powerboat that took us to the other side of the island. All along the way, we looked for dorsal fins and green/blue splotches in the water. We passed an area where they were known to congregate without seeing a single one. We continued on. I enjoyed the boat ride as it was quite swelly and bumpy and felt like I was riding a bronco as I held on for dear life. I’ve always enjoyed those kinds of boat rides, more like a rollercoaster than a boat ride. Maybe that’s part of the reason I enjoy sailing so much.

Finally, despite the constant concern in the back of my mind that we were not going to find any, we were told by the boat captain that indeed, there were Whale Sharks ahead and he asked us to put on our snorkel and fins and standby. I scrambled to get mine on and as soon as he said go, I was in the water with my GoPro in hand. I was so excited! The video is the footage from that entrance [go to medium.com/‌the-ascent/‌i-sailed-twenty-thousand-miles-to-swim-with-whale-sharks-a58acea7175e to view the video]. Forgive the shakiness and movement of the camera, I am not a professional videographer.

When I got in the water I didn’t see any sharks, but the water was beautiful and I could see large rock formations 20 meters below. I stuck my head out of the water and the captain pointed in a direction and I started swimming that way. As I swam, I could slowly start to make out something in the distance and it started to take shape. Finally, a magnificent creature started to come into view and it was heading in my direction. Then out of nowhere, another appeared to the right. In my first Whale Shark experience, I get 2 Whale Sharks in the same video clip. They came together so suddenly that Brian, my sailboat skipper, got stuck between the two of them as they passed, which you can see in this video.

I spent the next 30 minutes, recording Whale Shark after Whale Shark, and even had up to 3 Whale Sharks at one time. I was in Whale Shark heaven and I didn’t want to get out of the water. A couple we met in Cocos Keeling in 2018 was also with us and they said they had been circumnavigating for 17 years and this was also their first time seeing Whale Sharks. They were quite excited as well.

This is one of the most treasured experiences of my 3-year journey around the globe. I still get emotional thinking about it. Their majesty and grace as they slowly swim through the water, almost oblivious to us swimming around them, still blows my mind. According to the tour captain, they seem to enjoy it when people are swimming with them. We did have strict instructions to not touch them and avoid any contact. There was more than one time I had to swim back to avoid getting run over by one of them as it swam towards me. I can’t wait to do it again someday. Hopefully, it won’t take me 20,000 miles of sailing for my next adventure with them.

Article: World’s Largest Fish and One Tiny Island: Studying Whale Sharks on St Helena Island

On blog.nationalgeographic.org, posted by Georgia Aquarium, 11th April 2016{4}

Dr. Alistair Dove, director of research and conservation at Georgia Aquarium recounts his recent expedition to St Helena Island studying the world’s largest fish - Whale Sharks.

Approximately 2,500 miles east of Rio de Janeiro and just over 1,900Km west of the African country of Angola, lies St Helena Island: one of the most remote inhabited islands in the world. This stark volcanic peak juts up from the vast abyssal plain of the South Atlantic Ocean and covers just 122Km² of rugged rocky terrain, but is home to a multitude of diverse animal, plant, and marine life. It has even been called the Galapagos of the South Atlantic.

This tiny island is over 6,000 miles away from Atlanta, Georgia, where I and a team of researchers from Georgia Aquarium started our journey to study the world’s biggest fish: the enigmatic Whale Shark. This species lives throughout the tropical and sub-tropical waters of the world, but encounters are rare and those places where Whale Sharks gather reliably have become figurative goldmines of scientific discoveries about this extraordinary filter feeding shark.

Just getting to St Helena is a huge challenge; we first flew to Cape Town, South Africa and then boarded the RMS St Helena (1990-2018), which is the only form of regular transportation to the island and one of the last Royal Mail Ships in operation. We were aboard the St Helena for five days as she steadfastly steamed to our destination across a seemingly endless plain of seabirds and flying fish. Talk about remote! St Helena is so remote, in fact, that the island was chosen by the English as the location for Napoleon Bonaparte’s exile in 1815. He died there in 1821 and you can still visit his grave today.

Despite 500 years of this sort of exceptional maritime history, St Helena has only recently come to scientific attention, not only as an important habitat for Whale Sharks, but as part of the United Kingdom Overseas Territories, a group of islands that is home to more than 90% of the UK’s biodiversity assets. With the help of the Darwin Initiative, Georgia Aquarium’s partners in the St Helena Government, Mote Marine Laboratory, and the Marine Megafauna Foundation, we are so excited and proud to help study our flagship species in this beautiful and breathtaking location.

Georgia Aquarium is the only aquarium in the western hemisphere to display these elusive creatures and having them in this setting is an incredible research opportunity to complement our field research with studies of their growth, behaviour, health, and genetics. This helps us improve our interpretation of their behaviour seen in the natural setting, but there are still many tantalizing questions about Whale Sharks that we hope to answer.

We travelled to St Helena once before, in December of 2014, and we ventured back again in December of 2015. We started these expeditions because we think St Helena may play a vital role as a mating ground for Whale Sharks. The Whale Sharks of St Helena are an even split of adult males and females, which is different from the other places where Whale Sharks gather in numbers, where juvenile males dominate. This 50/50 mix of adults is incredibly important, because mating behaviours have never been documented in this species. Our main goal of the 2015-2016 expedition was to characterize these gentle giants in St Helena, how they use the island habitats, and where they go when they leave, and of course to stay ever vigilant for signs of mating behaviour. So how do we do all that?

We used a variety of techniques including computer-aided photographic identification, laser callipers to measure their size (and they can get big, over 35ft long), and several different types of tracking tags to help us figure out where they come from and where they go. We also worked with local ‘Saints’ to install an acoustic array, which is a network of underwater hydrophones around the island that listens for tags we put on Whale Sharks and other species. Over the weeks we spent in St Helena we tagged over 30 Whale Sharks and photographed dozens more - all these are collected to assist in our understanding of where they go, how they grow, how they reproduce, and how St Helena fits into a global population picture for this species, which the International Union for the Conservation of Nature lists as ‘Vulnerable’.

Another incredibly satisfying aspect of the expedition to St Helena was working alongside some of our fantastic research partners. We work with members of the Marine Section of the St Helena Government, and Mexican NGO Ch’ooj Ajail AC, in addition to Georgia Aquarium team members and other partners from the Marine Megafauna Foundation and Mote Marine Laboratory who couldn’t join us but materially supported our efforts. It was a demanding scientific agenda, but working with this talented crew made for a great trip. If you can measure the success of an expedition in the amount of data you generate, then we were certainly successful.

We’ve since returned from St Helena and unpacked our gear and washed the salt out of everything, including our ears. What lies ahead is a daunting task of compiling all the data we’ve collected, including terabytes of video and photo data and thousands of laser measurements, so we can begin looking for the answers to the questions we’ve been asking. We still have not documented mating behaviours, but we continue to learn more about their migratory patterns through the tagging studies and to identify new Whale Sharks through the Wildbook global database of Whale Shark sightings. With Whale Sharks, though, the more answers you try to find, the more questions you end up raising! It’s an incredibly exciting time to be studying this extraordinary species, especially in such a special location, and you can join in the excitement. Some of the animals we tagged automatically tweet out their locations in real time, and you can follow along on Twitter™ @Wheres_Domino, and at whalesharkwatch.org. We continue to learn and discover things about this magnificent species and I know there will be even more things to uncover. Anyone who says there isn’t amazing stuff still to discover in nature hasn’t put their head underwater lately, especially in places like St Helena.

Article: Durban ‘Environmental Disaster’ Reaches St Helena

By Emma Weaver, SAMS, published in The Sentinel, 25th May 2018{4}

The newly expanded National Trust Marine Team, now including St Helenians Luke Bennett, Jamie Ellick and Kenickie Andrews, has already made its first significant discovery: That a disastrous cargo spill, which resulted in about 2 billion tiny, toxic pellets of plastic being set loose into the ocean, may have just reached St Helena’s shores.

On Oct. 10, 2017 a container ship near Durban spilled 49 tons of ‘nurdles’ - pea-sized plastic pellets used as exfoliating beads or to make larger plastic items - into the ocean. This is comparable to an oil spill, said Di Jones of the Dolphin Conservancy to IOL News on Oct. 24. There is a disaster in the making.

Three months later, a Communication Director from the South African National Department of Environmental Affairs told News24 that It has become clear, due to the amount of nurdles spilt, and their size, that the clean-up operation is going to be long and difficult. To date, only 28 percent of the 2 billion nurdles spilled in October have been recovered. According to the nurdle spill data website, the pellets have washed as far North as Tofo, Mozambique and as far South as Yzerfontein, South Africa. And May 16, St Helena’s National Trust Marine Team found that some of the 72 percent of nurdles that had not yet been recovered, had washed as far West as St Helena.

Luke, Jamie and Kenickie - along with trainer Leigh Morris - visited Sandy Bay Beach May 16 for the first of the team’s weekly beach cleans. The aim of the weekly cleans is to collect information about what washes up on St Helena’s shores - on their first visit, the Marine Team members found large quantities of nurdles. We have found small numbers of nurdles on Sandy Bay Beach over recent months (mixed in with other micro-plastics), but the very large and very visible amount found this week is highly significant, said Marine Team member/trainer Leigh Morris.

The National Trust will be working with both the British Antarctic Survey and the Ocean Conservancy for their normal weekly beach cleans; this week, though, the team turned to Lisa Guastella, the South African Oceanographic Consultant that is coordinating the nurdle-spill reports.

The 5mm-diameter, round, translucent, white nurdles found on Sandy Bay [Beach] corresponds precisely to those lost in a spill in Durban harbour, east coast of South Africa after a freak storm on Oct. 10 last year, Lisa said. The National Trust is sending a sample to Lisa for confirmation, but Lisa believes the timing of the find is significant. Ocean-current theory suggests some [nurdles] will have entered the South Indian Ocean gyre and subgyres, while some may have ‘leaked’ westward into the South Atlantic Ocean, where expected current trajectories place St Helena Island in the pathway to possibly NE Brazil, she said. The timing and location of those found at St Helena fit in with expected ocean current transport.

This nurdle discovery, the remnants of an environmental disaster reaching St Helena’s shores, comes at the same time the island is building up its Marine Protected Area practices and policies, and focusing on sustainable fishing and its unique Whale Shark population. A high amount of nurdles in the water, could attract and concentrate additional environmental pollutants like DDT and PCBs. The iconic Whale Sharks (now officially one of The Seven Wonders of St Helena) are filter-feeders and will be taking these nurdles into their mouths, along with plankton and fish eggs, as they feed, Leigh said.

The build-up of plastics and their toxins within their bodies could have a major impact on this species in years to come, and the 5mm translucent white pellets being found on our beach at Sandy Bay look very similar to the fish eggs that Whale Sharks love to eat. Other species of fish, sea birds and other life will also mistakenly eat the nurdles, or eat smaller species that have previously eaten them. Over time the nurdles (like other micro-plastics) will become smaller as the sea breaks them down, and as they become smaller, other smaller marine life will consume them. Once they have been ingested, they will stay in the animal’s stomach and cause damage by making the animals become malnourished, and through the toxins they carry. Once in the food chain, these plastics are consumed by larger species, and then larger ones, etc. ultimately passing the nurdles up the food chain and building up a higher concentration in the top predators.

On May 19, Leigh returned to Sandy Bay Beach and found a significant number of nurdles on the volcanic sand once more. The Marine Team plans to return this week for further monitoring and clean-up. While worried about the long-term impact of nurdles and micro plastics in general, the team hopes to immediately begin aiding the worldwide tracking of plastic pollution in the oceans, in the hopes of helping St Helena’s Marine Protected Area survive over time.

From an oceanographic perspective, this find in St Helena is very exciting, Lisa said. Should people on St Helena come across nurdles in any other locations, please report these to Leigh at the National Trust; along with photographic evidence and details of the weather, wind and wave conditions at the time of observation, if possible.