On Saving Whale Sharks

The first (and only) time I saw a whale shark (Rhincodon typus) was in 2018 at the Churaumi Aquarium in Okinawa, Japan, one of the few aquariums in the world to house them. I stared at the crowd-puller through the glass ceiling, mesmerised, as the 26-foot-long, polka-dotted giant glided almost in slow motion above me.

Because of their large size, whale sharks are often mistaken for whales. But unlike whales which are mammals, whale sharks are fish. Like all sharks, whale shark skeletons are made of cartilage, not bone (they are elasmobranchs). While the whale shark at the aquarium seemed huge to me, it was just average in size. They can grow as long as 20 m and weigh over 30 tonnes.

Gentle Giants

Found in warm tropical seas and oceans around the globe, whale sharks are the largest fish in the ocean, yet they are the gentlest of creatures, posing no threat to humans. The polka dots and line patterns on their dorsal or upper surface make them distinct and easy to identify in open waters. Like tiger stripes, the patterns are unique to every individual, and scientists use them to identify one individual from another.

In sharp contrast to their size, their diet consists of small fishes such as sardines, anchovies, mackerel, fish eggs, larvae, crustaceans (such as krill), and zooplankton. While they have more than 3,000 teeth arranged in 300-350 neat rows, these are very tiny and useless. Instead, whale sharks have filter pads in their cheeks to sieve out food from the large amounts of water they gulp in (filter feeders). And since they need to eat in large quantities, they follow schools of fish and track krill and plankton blooms.

In 2020, scientists in Japan observed microscopic teeth-like structures called dermal denticles clustered on the eyes of whale sharks. These are modified teeth normally found on the bodies of all shark species, protecting them and helping them swim faster. Scientists believe the dermal denticles function as an armour protecting their eyes.

Whale sharks are solitary creatures but congregate seasonally at specific sites to breed and give birth to young ones. Large congregations of several hundred (and sometimes 1,000) individuals can be found off the coasts of Western Australia, northwestern Madagascar, Seychelles, the Yucatan Peninsula in Mexico, and Ticao Pass in the Philippines. Scientists have tracked whale sharks and mapped a few of their congregation sites and migratory paths using satellite tags. They found that most of the sites and paths they mapped overlap with some of the busiest shipping routes and ports, and have identified the Arabian Gulf, northwest Madagascar, the Gulf of California, and the Red Sea as hotspots where whale sharks face a high risk of collision with ships.

Saving whale sharks

In India, whale sharks are frequently sighted along the coasts of Odisha, Andhra Pradesh, Gujarat, and the Lakshadweep islands. Between March and June each year, whale sharks congregate in large numbers off the coast of Saurashtra, Gujarat. Here, they were excessively hunted between the late 1980s and 2000 for their fins and liver. While the fins entered the international shark fin trade, the oil extracted from their livers was used for waterproofing artisan fishing boats. This disturbing discovery was brought to light in 2000 in the documentary “Shores of Silence” by acclaimed wildlife filmmaker Mike Pandey. Following this shocking revelation, the NGO Wildlife Trust of India (WTI) began surveys to investigate the severity of whale shark hunting along Gujarat’s coastline and measured the socio-economic status of the fishing communities involved. In May 2001, the Ministry of Environment and Forests added whale sharks to Schedule 1 of species under the Wildlife (Protection) Act 1972. This was the first time a species of fish was protected under Indian law, receiving the same level of protection as the tiger. However, granting legal protection didn’t make a remarkable difference on-ground. To bridge the gap between law and practice, in 2004, WTI launched the Whale Shark Project, teaming up with local groups, including the Gujarat Forest Department, to initiate awareness programmes to educate fisherfolk on the new legal status of the whale shark. Fishers were dissuaded from hunting whale sharks and encouraged to rescue and release beached individuals and those accidentally caught in fishing nets. They were monetarily compensated for any damage to their fishing equipment. A specially designed smartphone app (called Vhali Watcher App in Gujarat) introduced by WTI now helps fishers share the location of whale sharks they sight or rescue during their expeditions at sea (coordinates are noted and uploaded when back in cell network; rescues are documented on video etc.). The success of these initiatives in Gujarat has helped WTI and their partner organisations to replicate these programmes in Kerala and Karnataka (Malpe and Mangalore). Two decades of persistent conservation efforts have finally borne fruit with reports of more sightings. A 2019 study by marine biologist Dr Divya Karnad, Assistant Professor at Ashoka University, and her InSeason Fish research team found that fishers across the country’s coasts recognised whale sharks as a species protected by law and released individuals accidentally trapped in fishing nets.

Since 2021, there have been increasing reports of fishers spotting whale sharks close to the Andhra Pradesh coast. Experts believe they congregate in the region between October and March, perhaps to feed on algae or plankton that bloom profusely after the monsoon. To prevent or reduce the number of whale sharks caught in fishing nets or beaching on the shore, the Andhra Pradesh Forest Department has adopted many components from Gujarat’s Whale Shark Project, including awareness programmes, compensation schemes, and mapping of whale shark sightings using smartphone apps.

Demand for shark meat

Little is known about the behaviour of whale sharks (and most shark species). The Indian Ocean has a rich diversity of sharks and related species, such as rays and sawfish, with nearly 160 shark species found in Indian waters. However, only 10 of these, including whale sharks, are protected under Schedule 1 of the WPA, 1972. Catching sharks for consumption is not illegal (except for the ten listed species), and India is one of the largest consumers of shark meat.

“The international trade in shark fins has significantly reduced in the last decade, but the demand for shark meat from local consumers has shot up, owing to it being a cheap source of protein”, says Karnad, referring to the findings of her studies on fisheries. Additionally, “loose implementation of rules and policies, lack of awareness or inability to identify threatened and not-threatened shark species, makes conserving them difficult”, she adds. Unlike whale sharks, many rare and vulnerable shark species do not have distinctive features, which makes identification difficult. As a result, rare shark species find their way into fish markets and consumer kitchens. Quick action is the need of the hour to save rare sharks and other elasmobranchs, but also to prevent over-exploitation of the more common shark species. Given that grassroots-level programmes involving local fisher communities have helped turn the fortunes of the whale shark, similar awareness campaigns accompanied by better law enforcement will positively impact the conservation of other shark species as well.