Pancake sharks: The cousins are in trouble
Reversing overfishing, climate change, and population growth can seem insurmountable. Safina Center Fellows strive to amplify the global conservation discussion and, in targeted ways and places, overcome some of these obstacles. They bring a wide range of skills, engaging in every way from primary research to policy to popular media. They make a difference.
Where the rubber meets the road to change, the drive to redefine the future of our damaged oceans starts with the belief that progress is possible. —Carl Safina
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The following interview with shark experts and Safina Center Fellows, Demian Chapman and Debra Abercrombie explores sharks less iconic cousins, rays and skates, aka, pancake sharks.
What do you mean by “pancake sharks?”
Demian: It’s just a term I use to help people realize that sharks, rays and skates are all related. When you talk about rays and skates, many people are just not that interested. If you say they are “flat sharks” or “pancake sharks,” people are automatically more interested because people tend to like sharks (or at least feel strongly about them). There are actually more rays and skates than there are sharks, in terms of species, and they are by themselves interesting, ecologically important and commercially valuable animals.
So there are more species of rays and skates than there are of sharks?
Demian: Let’s talk about batoids – that’s rays, skates, guitarfish and sawfish. We know there are about 500 species of sharks and over 600 species of batoids. And even though there are more batoid species, we know so much less about many of them than we do about many of the shark species. Even the number of species is changing because researchers are finding that some batoids that were described as belonging to only one species are, in fact, actually a complex of different species. The manta ray, for example, was thought to be one globally distributed species, but has been recently recognized to actually comprise at least two – one that lives over coral reefs and one that likes open water. And the manta ray is an iconic animal in the public eye and the subject of a lot of research. Imagine then what we have left to learn about some of the other batoids that are considered more mundane.
Most people are aware that sharks are heavily fished. But their cousins, the batoids (rays and skates) are often found right alongside them in fish markets. Photo: Demian Chapman
People do seem to be very attracted to mantas.
Debra: Yes, they are definitely among the best-known and most charismatic of the batoids. Even so, manta rays and their close relatives the devil rays (mobula rays) are fished for their meat and gills. As they feed, they filter plankton out of the water column and have special structures called gill rakers that they use to separate the plankton from the water. Those gills are used in Traditional Chinese Medicine. The idea is that if you crush up gill rakers and take the powder in a tonic, it will detoxify your blood. There’s no real basis for this claim but people believe it will help, and the demand has been created, so the gill rakers are traded.
I understand why in the past, when wild animal populations were much more robust and the human population was much smaller, wild animal parts used for medicinal ingredients could be somewhat sustainable. But now, with wild populations plummeting and the human population boom in China, that really spells disaster.
Demian: I think what may be happening is that people who grew up with Traditional Chinese Medicine as the norm, and who are now part of the booming, more affluent middle class, have more disposable income and are also getting older. They are starting to struggle to maintain their health and turn to Traditional Chinese Medicine when modern medicine begins to fail. With any luck, if the animals can weather the current storm, the younger generation in China might not buy into these traditional medicines as much. If this happens, then the demand for Traditional Chinese Medicine that relies on wild animal parts will diminish considerably.
Does our lack of interest or ignorance about the other batoids cause problems?
Demian: People see mantas kind of like whales—they seem harmless, graceful, awe-inspiring… But in some ways many of the rest of the batoids are like the “red-headed step child.” People just don’t seem to be that interested in them unless there’s a sensational headline, like someone getting stung by one at the beach. As a result, research money and conservation efforts go more toward protecting the more charismatic sharks or species that are commercially important in first world countries. While these species definitely need research and management attention, a recent paper produced by the International Union for the Conservation of Nature (IUCN) highlighted that batoids were ranked as even more threatened than sharks. Sawfish and guitarfish, for example, are some of the most endangered and vulnerable marine fish on Earth, and there is a very real possibility that some of them could become extinct within our generation.
Tell us more about sawfish and guitarfish—most people have never heard of them.
Debra: Sawfish are all endangered or critically endangered. They used to be very common in tropical or subtropical waters, but now they are almost extinct. Most countries that used to have sawfish haven’t seen them in decades. They’ve gone locally extinct. Sawfish get caught in coastal gillnets and in trawls. They aren’t the target of the fishery but get tangled in nets and wind up as bycatch. Back when they were abundant, sawfish were killed as a nuisance to the fisheries. Locals would sell the saw (rostrum) as a curiosity. But nowadays sawfish fins are quite valuable in the fin trade in China, mostly for the traditional delicacy, shark fin soup. Sawfish have become one of the highest value fins in the world, especially now that they are so rare. It’s a strange history—no one ever really targeted sawfish. Now, even though it is illegal to catch and kill them, they are so rare and valuable that sawfish are rarely released alive even when they are accidentally caught in a net.
How sad to watch such unusual, magnificent creatures like sawfish go extinct–for soup!
Debra: Yes, indeed. They are a true ocean giant, with the largest species growing to lengths similar to the longest white sharks (20 feet). There are five species of sawfish and they are all in big trouble. The only places where we know that we have viable and well-protected populations of sawfish are in and around the Everglades (Florida) and also off Northern Australia. There may still be some in the Bahamas and in Brazil, but more research efforts are needed in these areas. Sawfish need a big stretch of protected habitat–they live near the coast and need mangroves and seagrass. And places where net fishing is not that common.
What about guitarfish? Are they also killed for the fin trade?
Demian: Guitarfish look like a cross between a shark and a ray. Unfortunately, they are also highly valued in the fin trade. We recently conducted genetic testing on some high value fins in Hong Kong that were traded under the name “Qun.” These fins sell for close to $1,000 a kilogram. We found they were all guitarfish. For the most part, the trade in guitarfish fins is completely off the radar of conservation organizations and management agencies. If this doesn’t change they will most likely wind up as endangered as the sawfishes.
There are a lot of claims in the media these days that the demand for shark fins has greatly diminished in China and that this will “save the sharks.” Is that true and will it save the batoids as well?
Demian: Well, it’s more complicated than that. Even as demand for fins diminishes, there is still a huge, global trade in fins of sharks and some batoids. And lets not forget that we also capture skates and rays in huge numbers for their meat, as well as manta and devil rays for their meat and gill rakers. We have to address these issues as well.
So from your point of view, what do you recommend?
Demian: I think that it isn’t rocket science. We just need to make some investments into researching batoids and in batoid conservation. With the limited resources we have at present, research money tends to go to the charismatic ray species such as mantas, which is okay if they are the ones who truly need it most. But sometimes less iconic species need it much more.
Debra: Readers probably know a bit about shark conservation and have even signed petitions for shark conservation efforts. These days there’s a lot of investment in shark conservation and high profile media attention. But if you pause, take a broader perspective and consider these lesser-known relatives of well known sharks, you’ll see that batoids are in bad shape too! There are all kinds of “pancake sharks” out there and many of them need our help.