Being a magnificent, ethereal ocean giant that traverses the deep and mysterious blue like a BOSS does not, alas, protect you from the reaches of industry and human impact on the environment. Far from it! Along with countless other marine species, manta ray populations around the world are now fighting for survival against man-made pressures including fishing, habitat loss, pollution and climate change and both Oceanic and Reef manta species are listed as Vulnerable by the IUCN.
One particularly worrying and relatively new threat to these colossal, briny beasts is that of the gill plate trade. I have mentioned in a previous post that manta rays have specialised gills which they use to filter feed. Inside each of a manta’s ten gill slits is a set of feather-like gill plates (a circle of thin cartilage filaments) which trap planktonic food as water passes through a manta’s mouth and out of through the gills. Manta and mobula rays are now being hunted specifically for their gill plates which are extremely valuable for their use in Traditional Chinese Medicine.
Gill plates are dried and usually eaten in a soup (see image below). The soup may not look all that appetising to our Western tastes (yup, it's garnished with pipefish) but retailers promote that consumption of the plates can treat all manner of health issues ranging from asthma to chicken pox to cancer and that their filtering properties help to boost the immune system and detoxify the blood... all of which helps to explain why so many people are slurping down this 'wonder-drug', pipefish and all! However there is of course no scientific evidence to back up any of these claims, as is the case for so many of these Traditional Medicines made from desperately endangered and ill-treated animals.
What makes this story all the more frustrating is that research into traditional literature has revealed no mention of gill plates. It seems they are not actually a true Traditional Medicine but a remedy invented in recent years by Chinese retailers seeing an opportunity to market new products as 'revived' ancient medicines, playing on the fears of consumers over disease outbreaks such as Bird Flu and SARS. The result: big new manta and mobula rays fisheries popping up in India, Sri Lanka and Indonesia.
That alone sounds like enough for a big, flappy, cartilaginous fish to have to deal with but sadly there is more to tell. Further posts to follow soon on other threats to mantas and what you can do to help protect them. You can read more about the gill plate trade on the Manta Trust's website.
Thanks for reading!