A man carries a ray by a gill slits (top); each of these is encircled internally by feathery prebranchial appendages known as gill plates; (left) a ray dealer cuts up the large wings into slices which will then be dried over several days at the fish processing beach nearby; (right) gill plates are removed from a large ray. (Jonathan Browning)

Sri Lanka - ‘It’s not like chicken farming’: why manta rays are chopped up in Sri Lanka

The gill plates of the extremely intelligent fish – many species of which are already categorised as endangered – are sold across east Asia as remedies said to have ‘no basis in medical science’

Every morning, starting at 3am, Lakshan hacks up manta rays. A wholesale buyer who plies his trade at Sri Lanka’s largest fish market, in the city of Negombo, just north of Colombo, he jostles with fishers offloading their catches. His business is primarily to find fresh tuna but he also buys 700kg (1,540lb) of manta and devil rays every day.

He doesn’t want the ray’s meat, which most Sri Lankans don’t eat. Instead, he’s after the gill plates: cartilage that helps manta and devil rays filter out microorganisms in ocean waters.

In a courtyard across from the market, Lakshan dries the gill plates on a corrugated iron board. Then he sells them to another trader for as much as $130 (£104) per kilo. It seems a high price, but Lakshan (who gave only his first name out of concern for his trade) needs 5kg of fresh gill plates for every kilo of dried ones. He has only a vague idea what happens to them afterwards. “We heard they sell it to the Chinese because they eat them,” he says.

Dried gill plates are indeed often sold in medicine and dried seafood markets across east Asia, but are not used in traditional Chinese medicine. The growing demand for ray gill plates stems from market vendors using them to make soup that they tout a remedy for various health issues. The conservation charity Manta Trust calls these gill-plate concoctions “a pseudo-remedy” that has “no basis in medical science”.

The demand for gill plates has generated a sprawling cottage industry. Small-scale fisheries across Sri Lanka kill manta and devil rays (collectively known as mobulids), including endangered and vulnerable species, just to export their gill plates. A recent study showed that more mobulid rays are caught in Sri Lanka alone than the annual global catch across large industrial purse seine fisheries (huge operations that use curtain-like nets to scoop up marine life by the tonne). Their sizes are also declining, the study says.

Most mobulid species are classed as endangered, which means – according to the International Union for Conservation of Nature’s criteria – their populations has reduced by between 50% and 70% in the past decade. Meanwhile, the number of mobulids being caught continues to grow, with India, Indonesia and China the biggest culprits, feeding a thriving trade centred in Guangzhou, China, and Hong Kong.

Sri Lanka fishers don’t specifically target mobulids. Instead, the rays get entangled in gillnets used to catch yellowfin tuna, billfish and sailfish. Most Sri Lankans don’t eat them, though some add dried ray meat to curry; there’s little to no demand for the fresh meat.

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