Big-nosed giant guitarfishes and wedgefishes are now the most endangered marine fish group. Will the international community step up to protect them from trade and exploitation?

rhino ray

Many scientists wait for their whole careers to see their predictions proven correct — and if that happens, it’s often cause for celebration. But for conservation scientists who study threatened species, it can be a gut punch to learn your prediction’s come true.

For Alec Moore, a conservation biologist at Bangor University, that’s exactly what happened.

In 2016 Moore participated in a symposium focusing on sawfishes, which were then considered the most endangered marine fish in the world. His talk, however, focused on emerging threats to a similar group of fishes called guitarfishes, a type of ray related to sharks.

At the time Moore said several of the 55 known guitarfish species faced a risk of extinction. He then called for “comprehensive and coordinated action” for guitarfish that could be conducted in conjunction with current sawfish conservation efforts — which themselves arrived almost too late.

“While great conservation work is now being done on sawfishes, we have to acknowledge that it had to get to an absolutely critical point before widespread efforts took place to protect them from total extinction,” Moore tells The Revelator. “I wanted to highlight that we would soon be in a similar situation with guitarfishes if we didn’t act now, while there were still some left.”

Last month the IUCN Red List announced that things had indeed taken a turn for the worse, as Moore had feared: Six species of giant guitarfishes and ten species of wedgefishes have now overtaken sawfish as the world’s most endangered marine fishes. Of the 16 species, 15 have been assessed as “critically endangered.”

“The wedgefishes and giant guitarfishes face an extremely high risk,” says Peter Kyne, a senior research fellow at Charles Darwin University. “Their critically endangered assessment means that these species are one step away from extinction.”

In response marine conservation biologists studying the species have dubbed the group “rhino rays” — an allusion to the terrestrial poster child of conservation. The new name also echoes back to the rhino rays’ taxonomic order — Rhinopristiformes — which itself stems from the fact that the rays have big, interesting noses.

Decisions pending this month could determine the fate of these increasingly rare fish.

What Are Rhino Rays, And What Threats Do They Face?

These shark-like rays live on the seafloor, in shallow tropical water close to shore. Some of them swim throughout the Indo-Pacific, while others have much more limited ranges.

“The false shark ray is only known from a single location, the Banc d’Arguin National Park in Mauritania,” says Kyne. ”The clown wedgefish has only been collected from fish markets in Singapore and Java, Indonesia, so its actual range and habitat are unknown.” He notes that many details of the biology of these animals are currently unknown to science.

What we do know is that they’re almost all at risk.

“A combination of factors explains their high extinction risk,” Kyne explains. This includes their slow reproductive rate, the life in shallow waters — which overlaps with “some of the most intense and increasing coastal fisheries in the world” — and their exploitation in fisheries both as target species and bycatch.

wedgefish
Bottlenose wedgefish (Rhynchobatus australiae) after processing at Kota Kinabalu fish market, Sabah, Malaysia. Photo: Peter Kyne, courtesy IUCN Shark Specialist Group

Living close to shore makes it easy for these species to be over-exploited. Giant guitarfish fins are some of the most valuable in the lucrative international shark fin trade, but they also face less well-publicized threats, including an increasingly popular dish called “dragon fish” made from boiling their heads until they become soft enough to eat.

CITES Happens Soon, But Is It Too Late to Help Rhino Rays?

With these threats now becoming better understood, the governments of the world may now decide what to do about them.

Later this month the 18th Conference of the Parties of CITES (the Convention on International Trade in Endangered Species) will take place in Geneva, Switzerland. This international meeting focuses on, you guessed it, regulating international trade in endangered species. Protections dozens of species are on the agenda, including elephants, mako sharks and rhino rays.

CITES has multiple levels of protection, called Appendices. Placing a species on a CITES appendix, called “listing,” triggers or inspires conservation action. The rhino rays are proposed for listing under CITES Appendix II, which, if passed, would only allow international trade in related products when an exporting government could demonstrate that it’s conducted sustainably.

“CITES Appendix I listings, which make commercial trade illegal and often result in full protections in countries globally, have been fairly rare,” says Luke Warwick, the associate director of the Wildlife Conservation Society’s shark and ray program. Most CITES-protected sharks and rays, indeed 90 percent of listed species, appear under CITES Appendix II. While it doesn’t offer full protection, “it pushes countries toward sustainable fisheries management measures — the big gap for sharks and rays outside hyper-developed countries.”

A CITES listing would just be a start to protect these species, “but it is a really important step to complement these new IUCN assessments,” Warwick says. “It’s a great motivator for governments to act. By including a policy driver with that new science, these first steps can be used to facilitate change at the legislative level and on the water in priority countries globally before these animals disappear forever.”

Necessary, But Not Sufficient?

CITES can be a powerful tool for the conservation of threatened species, but it has limits.

“CITES relates only to international trade, and wedgefishes and giant guitarfishes are also caught, traded and utilized domestically,” Kyne says. “To conserve these species and permit their recovery, a range of measures will be required.” He says a major priority would be nation-level species protections and catch prohibitions. “Marine protected areas may also have a role to play, however we know little about the connectivity of populations and their movement patterns.”

Giant shovelnose
Giant shovelnose rays (Glaucostegus typus) at Heron Island on the Great Barrier Reef. Photo: Colin Simpfendorfer, courtesy IUCN Shark Specialist Group

As with any endangered species, he adds, “conservation and management will be dependent on effective enforcement, which can be challenging in developing tropical nations who may lack capacity and resources, and where management needs to be balanced with food security and local livelihoods.”

Experts say the new Red List assessment of the rhino rays is an urgent call for action: If we’re to avoid the extinction of a fascinating group of fishes, we must act now to protect them. And while a CITES Appendix II listing won’t entirely solve the problem, it’s an important step. For now we have to hope that the government representatives attending CITES will do the right thing and protect these rhinos of the sea — before some or all of them disappear forever.

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David Shiffman

is a marine biologist specializing in the ecology and conservation of sharks. He received his Ph.D. in environmental science and policy from the University of Miami. Follow him on Twitter, where he's always happy to answer any questions anyone has about sharks.