Threatened gentle giants: both species of manta ray added to the IUCN Red List

Manta rays are true gentle giants; though they can grow more than 20 feet wide from wingtip to wingtip, they eat only plankton. Swimming with these animals is a rare thrill for SCUBA divers, and manta-viewing ecotourism is worth over $100 million each year. Like many species of sharks, manta rays grow slowly and reproduce rarely. According to Dr. Nick Dulvy of the IUCN Shark Specialist Group, ” they give birth to an average of one offspring every two years…they are a long-lived species with little capacity to cope with modern fishing methods.”  They also migrate across huge distances, regularly crossing between national boundaries and spending much of their time on the high seas, making management difficult.

Photo credit: David Shiffman (Georgia Aquarium)

Although their biology cannot support a large-scale fishery and their behavior makes any fishery inherently difficult to manage, manta rays are very much in demand. At least part of them is: their gill rakers. According to Lucy Harrison, program officer for the IUCN Shark Specialist group, “Increasing demand for these fishes’ filter-feeding system for traditional Chinese medicinal purposes, especially in Hong Kong, is rapidly driving down their population everywhere.”

By some measures, the global population of manta rays has declined by more than 30% in recent decades, with some local populations facing much larger declines.  Earlier this week, an IUCN Shark Specialist Group team led by Andrea Marshall has concluded that both species of manta ray (the giant manta Manta birostris and the reef manta Manta alfredi) should be declared Vulnerable* to extinction.

The IUCN Shark Specialist Group recommends that several steps be taken to protect mantas from further population declines. These include discussing the value of international conservation treaties, such as CMS and CITES, for both species as well as national-level policy changes in countries that fish for mantas. Some of these proposals may benefit from the support of the online conservation community, so please stay tuned! I’ll continue to report on these suggested policies as they moves forward.

* “Vulnerable” in the context of an IUCN Red List status should be capitalized, as should other IUCN Red List statuses. For more information on what “Vulnerable” means, please visit the Red List website here.


  1. Dashark · November 14, 2011

    Thank David (and IUCN, this is both timely and important.
    More about people trying to do something about it on

  2. Dr Brian W Darvell · November 15, 2011

    In June, elsewhere, I said:
    The largest Chinese traditional medicine building in Guangzhou is piled high with them (along with millions of sea horses, pipefish and many others). This is not new. To say “now being targeted” is simply wrong. Send somebody to see – it is open to the street. Wander around and be appalled! 3 floors of horror. This is no secret.

    The whole ‘magic’ business has to be dealt with properly, and exposing the tonnage of the take – the sheer numbers of animals involved – is essential. Deer, snakes, pangolins, monkeys – everything.

    This will all be said to be an interference in Chinese culture, and therefore racist. But it is about time that medieval witchcraft was exposed for what it is: an exploitation of the gullible in their hope of remediating their parlous condition in a state of general poverty – charging (relatively) huge sums for the privilege. Oddly, the richer people get, the more they subscribe to it! Destruction of the natural world cannot be excused by the pathetic hope of 4 billion people that mumbo-jumbo can improve sex drive and cure all cancer. Yin, yang may be worthy as a principle, but is not being observed – the take is hugely out of balance with the ability to renew.

    Then again, the principle that a person’s livelihood is sancrosanct will be invoked: you may not interfere with a trade. This must be countered: it is not acceptable that one man’s trade (actually, rather a lot!) should be to the detriment of everything else.

    In May 2009 I said
    You might like to note that the Chinese slaughter mantas in their thousands for their gill rakers for use in traditional ‘medicine’.

    I was taken to the largest Chinese medicine market in China, in Guangzhou, recently – a whole block of shops on three floors of the most amazing things. These included literally tonnes of dried seahorses – shops-full at a time, and similarly manta gills, 10s of thousands that I saw – boxes piled high.

    Mantas do appear to be getting infrequent – my last few dive trips have been very disappointing. I saw just one, briefly, over 12 days of diving in Indonesia …

    This is NOT a small, subsistence market, by any means. It is a massive, commercial operation that somehow has evaded notice. It can be added to the foul practices using of bear bile, tiger bone, seahorses etc etc for the magical, culturally-sanctioned, devastation of wildlife of all kinds. If it moves – eat it. It is about time that the centrality of Chinese activity in these matters was addressed properly, instead of pussyfooting around trying not to offend. Culture or long tradition is no longer an acceptable defence for anything, anywhere, now where commercial exploitation is involved. True subsistence use is hard to find, and altogether negligible in impact.

    Educationally, we have a huge task in front of us – the Red List on its own will achieve very little except make us angry.

  3. Cat · November 15, 2011

    Dr Brain Darvell, I am a Singaporean Chinese, never heard of manta gill rakers (peng yu sai) until Manta Ray of Hope… I have asked around, only few of the older generation have heard of it (mostly people of the Cantonese dialect – meaning they came from Southern China)… Anyway, now that more people are aware of the issue, hope we can all chip in.
    I have asked the Singapore AVA about seahorses, they gave me a vague answer that I couldn’t really recall – something to do with the CITES…
    We need more Yao Mings! & Wildaid!

  4. Paul · November 15, 2011

    [Comment Removed – Racism]

  5. Mark Bradfield · November 15, 2011

    I think its about time the issue of Chinese Traditional Medicine was brought out into the open and raised in profile on the international wildlife/biodiversity stage. Its too big an issue to ignore. It isnt just the Chinese we should blame though – all the people worldwide targetting animals for the trade are implicit. But as we all know where there is demand, there will be trade and its the demand that needs to be focused on. How do we achieve raising this profile? Through our individual parliaments etc, through WWF or can we harness the powers of Facebook etc somehow??

  6. Conrad Blickenstorfer · November 15, 2011

    I’ve had a chance to dive with dozens of giant mantas earlier this year, and the thought that even a single one of those majestic, magnificent creatures be slaughtered for their gills is simply unbearable.

    It probably will have to be a combination of protection and education as protective efforts alone won’t be enough to deter as long as there’s a lucrative market. I think China is struggling in many areas in becoming a responsible world citizen, and whatever efforts can be made to put conservation higher on their priority list will benefit all these animals driven to extinction for such dubious reasons.

  7. Steve Plant · November 16, 2011

    Being married into a Chinese family, I cant agree with some of the rampant anti-Chinese sentiment on a lot of these posts. The majority of Chinese have a great respect for nature. The point is they are totally unaware of the terrible slaughter involved in bringing them ingredients such as shark fins or manta ray gills. What is needed is education, education, education – if Chinese consumers were aware of the consequences of consuming these items then demand would fall drastically

    • WhySharksMatter · November 16, 2011

      I agree, Steve- I’m a strong believer in public education about environmental crises. They happen not because people don’t care, but because people don’t know.

      Just to be clear, though, are you saying there was anti-Chinese sentiment in the comment thread or in the post itself?

  8. Paul · November 17, 2011

    I’m very disappointed that my post has been removed and deemed to be racist.
    As far as I was aware disliking a nation due to skin colour or religion quite rightly is racist but because of a bowl of soup ?? I make no apologies for my stance as I’m very angry that as a nature lover and keen diver within my lifetime we could well see the extinction of some of the oceans most magnificent creatures. And like it or not this would predominately be down to one nation.
    You say the majority of Chinese are nature lovers, I disagree, have you ever been down the back streets of Hong Kong to an animal market?
    The animal cruelty has to be seen to be believed, the WWF would have a field day down there. I have also written to over 15 Chinese restaurants in my local area kindly requesting that they remove shark fin soup from their menu and politely giving them the full facts about
    the cruelty involved, I didn’t even receive a single reply let alone manage to convince any to remove this awful dish from their menu.
    You are right on one point though I believe education is the key however I also believe we haven’t got time to wait for the vast majority of China
    to become educated in these matters so if expressing anger and using strong words towards the consumers and suppliers is required then so be it. Censoring views just because they don’t fit in with your way of thinking or agenda is wrong, just ask the citizens of communist China who are apparently unaware of the terrible slaughter involved in bringing them ingredients such as shark fins or manta ray gills.

    • WhySharksMatter · November 17, 2011

      There’s a fine line near “criticizing a specific aspect of another culture” and we believed that your previous post crossed that line. I’m glad we agree that education is the solution.

    • Southern Fried Scientist · November 17, 2011

      Fine line? For real, David? Leaving a comment that adds nothing constructive to the conversation and stereotypes an entire group of people as savages thoughtlessly destroying the environment isn’t a fine line, it’s just plain old racism.

      To then come back and say “it wasn’t racist, and also, look at how terrible these people are” is also racist.

    • WhySharksMatter · November 17, 2011

      By “fine line” I mean that there are occasionally legitimate criticisms that can be made that may only apply to certain cultures. Obviously the level of stereotyping and hate speech that was found in the earlier comment was well beyond that line.

  9. Minz · November 18, 2011

    This makes me want to scream. Or cry. Or scream whilst crying, although that seems counterproductive. It seems as soon as one thing is fished out, people move onto the next one!

    Has anyone got a line to petitions and organisations doing something about this?

  10. Barbara · November 19, 2011

    I am glad that Mantas are finally listed on the IUCN Red list. and i hope it will go further as these animals need international protection on CITES.

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