Whale Sharks and Humans: Tourism, Conservation and Research | Sea Life, Islands and Oceania

WHALE SHARKS AND HUMANS

freediver with a whale shark

Whale sharks are known as gentle giants. They have never been known to attack a human. Whale sharks take little notice of divers, snorkelers and other human observers and gently go about their business even if people are near. About eight miles off the province of Papua in Indonesia, according to National Geographic, a group of whale sharks call on fishermen each day, zipping by one another, looking for handouts near the surface, and nosing the nets — a rare instance when the generally docile fish act, well, like the rest of the sharks.

Whale sharks are considered food in many countries They are hunted for their fins, used to make shark fin soup, and meat. Although the cartilage fibers in the fins are not good for making soup, they are sold as display or trophy fins in Asian restaurants. In Pakistan, the flesh has traditionally been consumed either fresh or salted, Many end up in Taiwan, where they are know as tofu shark after their soft, white flesh. Sometimes large ships accidently ram whale sharks and have to stop while the broken body of the shark slips off the bow and falls to the depths of the sea. Taiwan now has quotas of 65 a year.

Traditionally whale sharks have been hunted with harpoons. In some places quite a few have caught. Off of Gujarat, India, 591 were caught in 1999 and 2000 before catching them was banned. One of the largest whale sharks ever accurately measured was caught off Bombay in 1983. The large fish traditionally has been hunted in the Arabian Sea for its liver oil, which is used in waterproofing boats and as shoeshine. The meat is also eaten. Fishermen off India’s coast, particularly around Gujarat, have traditionally sought the sharks for their fins, used to make shark fin soup. The meat is also exported. Hunting has greatly reduced their numbers. In an effort to protect them, in 2001, whale sharks became the first fish to be added to India’s Wildlife Protection Act.

Okinawa Churaumi Aquarium displays whale sharks and is trying to breed them: It reported in 2016: As our effort for the world’s first captive breeding of whale sharks, we relocated one smaller female whale shark to an outside fish pen of three whale sharks in the Kuroshio main tank. Compared with their original size, they have grown 1.5 to 2 times in total length and 4 to 8 times in weight, so we need to secure the main tank with a sufficient space for immature female whale shark to be grown, eventually for the successful captive breeding of whale sharks. We are planning to add a smaller whale shark — total length about 11 to 13 feet (3.5 to 4 meters) — in the main tank to display with larger whale sharks in the future. Okinawa Churaumi Aquarium had succeeded in keeping whale shark for the first in the world and “Jinta” has the world’s long-term keeping record of whale shark. [Source: Okinawa Churaumi Aquarium, November 15, 2016]

Whale Sharks Conservation

20120518-Whale shark recovered from shallow water.jpg
Whale shark recovered from shallow water
Humans utilize whale sharks for food and their body parts are sources of valuable materials. Human activities, hunting, overfishing and poaching have considerably reduced the number of whale sharks in some places. Particularly noteworthy has been an absence of specimens under six feet. There are recent reports of live individuals being finned in the Maldives and Philippines. Whale sharks can also be injured by boats and propeller strike or tangled in nets and damaged fishing equipment.

The International Union for Conservation of Nature (IUCN) Red List lists whale sharks as vulnerable. They are the Convention on International Trade in Endangered Species (CITES)Appendix II, which lists species not necessarily threatened with extinction now but that may become so unless trade is closely controlled. In 2003 whale sharks were declared an endangered species by CITES and international trade restrictions on them were imposed. They are legally protected in Australian Commonwealth waters and the states of Queensland, Tasmania and Western Australia, the Maldives, Philippines, India, Thailand, Malaysia, Honduras, Mexico, in US Atlantic waters, and in a small sanctuary area off of Belize. Full legal protection is under consideration in South Africa and Taiwan.

In 1999 the whale shark was listed on Appendix II of the Bonn Convention for the Conservation of Migratory Species of Wild Animals. This identifies it as a species whose conservation status would benefit from the implementation of international cooperative agreements. This regulation has been enforced since February 2003, and requires fishing states to demonstrate that all exports are from a sustainably managed population, along with monitoring exports and imports. In Western Australian waters, Whale sharks are fully protected under the Wildlife Conservation Act of 1950.

In 2022, a video was posted that showed Spanish divers rescuing a trapped whale shark after it got caught in tuna fishing nets near the Strait of Gibraltar . “This is the first time, and I have been diving for many years, that I have seen a whale shark in Ceuta.,” a diver told Reuters. It took divers about four hours to release the shark [Source: Reuters Videos, December 9, 2022]

Studying Whale Sharks

Scientists know very little about whale shark. Jennifer S. Holland wrote in National Geographic, “The giant fish is hard to study in part because it is hard to find and track. By tagging individual specimens, scientists have learned that whale sharks can log thousands of miles in years-long trips. But they sometimes disappear for weeks, diving more than a mile down and resting in the chilly deep for a spell. No one has ever found mating or birthing grounds.[Source: Jennifer S. Holland, National Geographic, October 2011]

At Ningagola Reef whale sharks are being tagged with Hawaiian-sling pole spears with pop up tags that record depth temperature and other data. One of the main objectives is to determine where the sharks go when they leave the reef. Several tagged sharks went to the Indonesian coast where they are vulnerable to being caught by fishermen. Temperature and depth data indicates they spend most their time on the surface but sometimes dive to depths of more than 3,200 feet.

Whale sharks have also been tracked with real time transmitters attached to the shark’s dorsal fin since they spend so much time at the surface. Evidence from devices indicates that whale sharks migrate long distances. One individual was tracked migrating from the Sea of Cortez off Mexico 8,000 miles across the Pacific.

whale sharks at the Okinawa Aquarium

Isla Holbox off the Yucatán Peninsula near a major gathering place for whale shark and also serves as gathering places for scientists studying whale sharks. According to Smithsonian magazineL“Researchers have fastened IDs to about 750 whale sharks here since the scientists started studying them in earnest in 2003, and they hasten to say the procedure does not seem to hurt the animal. “They don’t even flinch,” says Robert Hueter, a shark biologist at the Sarasota, Florida-based Mote Marine Laboratory, which collaborates with Proyecto Dominó. The researchers have outfitted 42 sharks with satellite tags, devices that monitor water pressure, light and temperature for one to six months, automatically detach and float to the surface, then transmit stored information to a satellite; scientists use the data to recreate the shark’s movements. Another type of electronic tag tracks a shark by transmitting location and temperature data to a satellite every time the animal surfaces. [Source: Juliet Eilperin, Smithsonian Magazine, June 2011]

DNA from specimens caught in the Atlantic, Pacific and Indian Oceans are being compare to find out how closely they are related and maybe of there are separate subspecies or species. In an attempt to figure what whale sharks migration routes are a learn more about them a database called Ecocean Whale Shark Photo-identification Library (displayed a www.whaleshark.com ) has been set up. As of the late 2000s it had collected thousands of images and identified some 830 sharks by the patterns and markings behind their gills. To organize the pictures scientists borrowed a methods that astronomer use to line up pictures of stars. One of the main goals of the project is to map out the locations of where individual sharks are sighted and determine their migration routes.

Nuclear Tests Help Scientists Figure Out the Age of Whale Sharks

Data from Cold-War era nuclear bomb tests have helped scientists accurately age the world's biggest fish. The BBC reported: Whale sharks are long-lived but scientists have struggled to work out their exact ages. To date, scientists have tried to count distinct lines in the vertebrae of dead whale sharks. These act like rings in a tree trunk, increasing as the animal gets older. But scientists have been unsure about how often these rings can form and the reasons behind them. Now researchers say they have come up with a much more accurate way of determining the whale sharks' true age. [Source: Matt McGrath, BBC, April 6, 2020]

whale shark in the Andaman Sea

“From the late 1940s, several nations including the US, the Soviet Union, Great Britain, France and China conducted atomic bomb tests in different locations. One side effect of all these explosions was the doubling of an atom type, or isotope, called Carbon-14 in the atmosphere.“Over time, every living thing on the planet has absorbed this extra Carbon-14 which still persists. But as scientists know the rate at which this isotope decays, it is a very useful marker in determining age. The older the creature, the less Carbon-14 you'd expect to find.

"So any animal that was alive then incorporated that spike in Carbon-14 into their hard parts," said author Dr Mark Meekan, from the Australian Institute of Marine Science in Perth. "That means we've got a time marker within the vertebrae that means we can work out the periodicity at which those isotopes decay."

One of the difficulties with ageing these sharks has been in getting access to samples of vertebrae. This team managed to find two long-dead specimens stored in Pakistan and Taiwan. The study indicated that these creatures do actually live an incredibly long time. "The absolute longevity of these animals could be very, very old, possibly as much as 100-150 years old," said Dr Meekan. "This has huge implications for the species. It suggests that these things are probably intensely vulnerable to over-harvesting."

The scientists say their results explain why whale shark numbers have collapsed in locations like Thailand and Taiwan where fishing has taken place. "They are just not built for humans to exploit," said Dr Meekan. Long lifespans are often accompanied by late sexual maturity ages and long periods between giving birth, which means that whale sharks reproduce slowly and take a long time to come back — if they ever do — after they have been overfished.

Whale Shark Tourism

Snorkeling with and viewing whale sharks is a big tourism draw in some places and an important source of income in certain localities. Whale sharks are now established in several locations, including Australia, the Philippines, Oman, southeastern Africa, Seychelles, Maldives, Mexico, Belize and Honduras.

Whale sharks are docile and pose no risk to humans and are approachable. Tourists are often told to keep your distance, giving them the respect and space they deserve, but this advice is often ignored. Some divers have clung to the backs of large whale sharks and ridden them like cowboy at a rodeo by holding on to the shark's dorsal fin. Others have stroked the soft skin under the shark's throat and taken photographs of its stomach by aiming the camera through its mouth. Whale generally don't let this thing get to them but one thing they don't like is having somebody mess with its tail. When this happens the shark slowly dives out of range.

Explaining what it is like to be struck by a fin of whale shark, Steven Wilson wrote in Natural History magazine: “I felt a jolt in my lower back and suddenly found myself being propelled through the water. All I could see was the whirl of spots. It took me a moment to comprehend that another, much larger whale shark had struck me with its dorsal fin and was pushing me forward....Stunned but unhurt I dislodged myself. And swam back to the boat.”

Whale sharks tourism is big at Ningaloo Reef in western Australia, and in the Philippines, the Baja Peninsula of Mexico and Belize. The massive fish often glide near the surface. The Philippines has a couple places where whale sharks up show fairly often, attracted by fish-hand outs from dive companies and tourists swim with them off boats.. So many divers rode the whale sharks at Ningaloo reef that Australian government now prohibits the practice. Several are kept at aquariums in Japan.

According to Smithsonian magazine: “Shark tourism is growing. Graham, in a 2002 study of whale shark visitors to the small Belize town of Placencia, estimated revenues of $3.7 million over a six-week period. In the Philippines’ Donsol region, the number of whale shark tourists grew from 867 to 8,800 over five years. And a study found whale shark tourists spent $6.3 million in the area around Australia’s Ningaloo Marine Park in 2006. “It’s simple and more predictable than fishing,” Willy Betancourt Sabatini says of shark watching. The 12 men who work for him as boat operators and guides earn twice as much as they did fishing, he adds. “We respect the rules. People understand it very well.” [Source: Juliet Eilperin, Smithsonian Magazine, June 2011]

Swimming with Whale Sharks

Describing her experience diving with whale sharks at Isla Holbox off the Yucatán Peninsula, where hundreds of whale sharks gather, Juliet Eilperin wrote in Smithsonian Magazine: “It had taken an hour” by boat “to reach the sharks. The water was smooth and thick with reddish plankton. “There’s one of them!” a researcher cried out, pointing to a large, shiny dorsal fin. We motored closer, and I found myself gazing at the largest shark — about 23 feet — I had ever seen. Its skin was dark gray, glinting in the sunlight, with mottled white dots. [Source: Juliet Eilperin, Smithsonian Magazine, June 2011]

“Suddenly it seemed as if whale sharks were everywhere, though we could see only a fraction of their massive bodies: their gently curved mouths, agape as they sucked in volumes of water, or the tips of their tails, flicking back and forth as they glided through the sea. I donned a mask, snorkel and fins and prepared to jump in. Hueter had told me he thought the sharks’ cruising speed was one to two miles an hour — slow enough, I thought, to swim alongside one without much difficulty...Wrong.. I made a rookie’s mistake and jumped in near the shark’s tail. I never caught up.

“I tried again, this time hoping to swim out to an animal half a dozen meters away. It didn’t wait. Finally, I managed to plunge into the water near an animal’s head and faced an enormous, blunt-nosed creature, coming toward me at what seemed like a shockingly rapid rate. While I marveled at its massive nostrils and eyes on either side of its head, I realized I was about to be run over by a 3,000-pound behemoth. Never mind that it doesn’t have sharp teeth. I ducked. It cruised by, unperturbed. By the time I climbed back into the boat, everyone was ready with quips about how I had had to scramble to get away. I didn’t care. I had seen a whale shark.

Whale Shark Tourism in The Philippines

Tan-awan, Oslob (four hours from Cebu City) is a place where whale sharks are fed so tourists can view and swim with them. Whale shark watching is open from 6:00am – 12:30pm everyday the whole year round except on Good Friday. Viewing is limited to 30 minutes. All whale shark watchers must undergo orientation at the Briefing Center on the rules for interaction with whale sharks The following are the rules: 1) No feeding of whale sharks by unauthorized personnel; 2) Do not touch, ride, or chase a whale shark; 3) Do not restrict normal movement or behavior of the shark; 4) Do not use flash photography; 5) Do not create splash when entering the water; 6) Maintain a minimum distance of five meters from the head, six meters from the tail.

In 2013, David Loh of Reuters wrote: “Tan-awan, in the southern Philippines island of Cebu, used to be a sleepy village that never saw tourists unless they were lost or in transit. Yet now they flock there by the hundreds — to swim with whale sharks, the world's largest fish. Whale sharks are lured to the Tan-awan coastline of the Oslob district by fishermen who hand feed them small shrimp, drawing divers and snorkelers to see the highly sought-after animals, known as gentle giants of the sea. But the practice has sparked fierce debate on the internet and among biologists, who decry it as unnatural. [Source: David Loh, Reuters, March 12, 2103, March 13, 2013 /]

“'Some people are asking that we stop feeding, but if we stop feeding, what is our livelihood?' said Ramonito Lagahid, vice chairman of the Tan-awan Oslob Sea Warden and Fishermen Association (TOSWFA). 'We have to go back to fishing.' Lagahid says there have always been whale sharks in Tan-awan. He remembers seeing them even when he was young. 'They are always around when we go out at night to collect uyap,' he said, referring to a kind of small shrimp that the whale sharks are fed. 'Many times we have to stop fishing because the whale sharks are around.' /

Image Source: Wikimedia Commons, NOAA

Text Sources: Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; Wikipedia, National Geographic, Live Science, BBC, Smithsonian, New York Times, Washington Post, Los Angeles Times, The New Yorker, Reuters, Associated Press, Lonely Planet Guides and various books and other publications.

Last Updated March 2023