How these harmless creatures, these gentle giants of the deep, can be slaughtered on such an industrial scale is beyond belief.
The largest slaughtering facility for Whale sharks ever seen has been uncovered in southeastern China by Hong Kong based WildLife Risk.
The slaughterhouse, operated by China Wenzhou Yueqing Marine Organisms Health Protection Foods Co Ltd, is estimated to butcher over 600 Whale sharks - an internationally protected endangered species - every year.
Alex Hofford and Paul Hilton from the organisation said in a joint statement: "How these harmless creatures, these gentle giants of the deep, can be slaughtered on such an industrial scale is beyond belief."
Whale shark trade
The trade with Whale shark products - a large part of which ends up in beauty products such as shark oil health supplements, lipstick and moisturisers in the West - continues.
Despite international agreements The Pu Qi factory, which was discovered near Wenzhou - in China's southeastern Zhejiang Province - operates openly.
A manager at the factory, whom they identified as Li Guang, said shark products were being labeled as tilapia, a commonly farmed fish.
A four-year investigation
The revelations follow a four-year investigation, spanning from January 2010 to December 2013, by WildLife Risk, a marine conservation organisation.
It includes DNA tests, undercover footage and audio recordings of the findings, and was carried out in association with the New York Times.
The investigators says they were shaken by what they saw at the factory. Whale sharks, the biggest fish in the world, a tropical species the size of a bus (they can grow to 12 meters long) were butchered by hand on the slippery floor.
"It's a lot of carnage in one place, a lot of damage. It was pretty overwhelming", said Hilton. He and Hofford both visited the factory three times undercover, posing as buyers.
Other species found
Hofford said: "It was shocking. You go in there and they were laid out on the floor, all chopped up. You nearly want to vomit. When you have swum with them, it's very upsetting."
The investigation also found "countless" Basking sharks and Great white sharks - both protected under CITES - being slaughtered at the factory.
The international trade in products derived from endangered species is illegal or subject to controls under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) - and China is a CITES signatory.
'Carnage' for the sake of luxury products
"It's even more incredible that this carnage is all for the sake of non-essential lifestyle props such as lipsticks, face creams, health supplements and shark fin soup", the investigators said.
They learned that shark skins are sold as leather in the bag trade, while stomach, flesh and lips are sold in the restaurant trade as 'food'.
The meat is sold and consumed fresh, frozen or salted. The liver is processed for oil, the fins for soup, the offal for fish meal, the cartilage for use in Chinese medicine.
The meat of the Whale shark is among the most expensive in the world and sells for a high price in many Asian countries for example Taiwan, where a 10,000kg shark sells for as much as $21,400.
The real money-maker is the shark liver oil, extracted for skin care products, shoe polish products, and lipstick.
Shark liver oil trade linked to US company
The oil, often exported overseas to the West, is also used for omega-3 health supplements - and sold internationally in contravention of CITES regulations and Chinese national laws.
Manager Li Guang told the investigators that the oil was sent to another plant on China's Hainan Island, Hainan Jiahua Marine Products Bio-Pharmaceutical Company.
There, it is blended with other types of shark liver oil in preparation for export to western countries such as the US, Canada and Italy, the report says.
WildLife Risk identified one company which was receiving the product: Omojo, based in Washington State. Omojo's website says: "We control quality from end to end, ensuring 100% traceability - and 100% accountability."
Fins for soup and decoration
Whale shark fins are dried in Pu Qi and sent to Guangzhou, situated in China's southern Guangdong Province, where sold to restaurant owners who use them as ornaments.
The large fins are tied with red ribbons and placed on display in the windows of restaurants selling shark fin soup, to attract customers, the investigation found.
On a single day in 2012, investigators counted 260 large fins, 136 of them from whale sharks and the rest from basking sharks and great white sharks, for sale in the dried seafood markets of Guangzhou.
Call on consumers to reject whale products
"We are calling on China's regulatory authorities to enforce the international agreements on this illegal activity now, before these animals are brought closer to extinction", WildLife Risk said.
The report says if these animals are to avoid being hunted to extinction, consumers must be persuaded to reject shark-related products.
"We must hold individuals accountable for their violation of international protection laws and demand transparency so that consumers can make informed decisions about the products they buy."
There may be many more such factories
The Pu Qi factory is only one of many engaged in the trade of endangered sharks and their products throughout coastal China, the investigators believe.
The sharks at the Pu Qi factory are being caught off the coast of the South China Sea where the animals pass on their migratory journeys around the world's oceans.
Other areas they pass include famous Whale-shark watching spots These extensive journeys across the world's oceans, take in such famous whale shark-spotting sites as the Ningaloo Reef off Australia's northwest coast, and waters off Indonesia, the Philippines and Mexico.
An 2005 Australian government paper also reported that Taiwan was associated with Whale shark fishing - owing to a huge reduction in sightings of large individuals around the Taiwanese coast. Since then Taiwan has acted to ban the Whale shark industry.
They are worth more alive than dead
There is a compelling argument for protecting whale sharks in their natural habitats. These rare creatures are worth far more, in economic terms, alive than dead, WildLifeRisk says.
"Educating local communities about the value of a live whale shark and promoting the transition from hunting to eco-tourism is a practical means of achieving both a sustainable economy and a healthy ocean."
"It has been estimated that whale shark tourism, mainly through recreational diving, is worth about $47.5 million worldwide."
Call for educating fishermen and local communities
A large whale shark can be sold for around $31,000 at port. Opportunistic fishermen based in ports along the eastern seaboard of China, from Guangdong Province in the South to Shandong Province in the North, are catching whole whale sharks either as by-catch, or as targeted by-catch (intentionally), the report states.
The sharks found in the factory are protected in China, and it is illegal to hunt them without a special permit granted by the Chinese Government.
However, the investigation revealed that whole whale sharks were being obtained from Chinese coastal fishermen through an elaborate network of agents and middlemen, many of whom "may be unaware of the full conservation status of whale sharks" the report said.
May Mei, China program manager of WildAid - an NGO based in the US and China which campaigns to stop people eating shark fin soup - called the report "pretty shocking" and "convincing".
"Our control system just isn't good enough. And we have to teach fishermen what's a protected species and what's not. Supervision at all levels has to improve, including at customs departments."
Decreasing numbers reported worldwide
The whale shark's large size, slow speed and habit of swimming near the surface make them easy to kill.
Complete figures for the global population of whale sharks are not available, although a monitoring program in 16 countries has been implemented using photo-identification. The whale sharks have unique patterns used to identify each shark.
Whale shark numbers are decreasing, and it is "now globally vulnerable to extinction", says UK charity Shark Trust, which works for worldwide shark conservation.
"Whale sharks catches have greatly declined over recent years, an indication of the underlying decline in population numbers."
Whale sharks are listed as 'vulnerable' by the International Union for Conservation of Nature, meaning they are within the ‘extinction risk' category.
Sophie Morlin-Yron is a freelance journalist.
The WildLife Risk report: Planet's biggest slaughter of whale sharks exposed in PuQi, Zhejiang Province, China.