Voracious Demand Threatens Manta and Mobula Rays

A manta ray off the island of Hawaii.James L. Wing for The New York TimesA manta ray off the island of Hawaii.
Green: Living

A few years ago, something surprising began turning up in Asia’s fish markets: the gill rakers of manta and mobula rays.

Manta and mobula ray gills at a market.Manta Ray of HopeManta and mobula ray gills at a market.

Shawn Heinrichs and Paul Hilton, photographers who have been monitoring the international soaring trade in shark fins, decided to find out what was going on. The appearance of those creatures in the markets “came as a real shock to us,” Mr. Heinrichs said by phone from Indonesia. “They don’t even taste good, so what was the reason?”

On Saturday, the conservation organizations Shark Savers and WildAid released the results of a comprehensive global study showing that these species have been driven to the brink of extinction within a chillingly short space of time. The main reason is demand from China, where their gill rakers (filaments that filter the animals’ food from the water) are marketed as a supposed cure for a variety of ailments.

The southern Chinese city of Guangzhou is the hub of the trade in the dried parts, which retail for as much as $500 a kilogram (roughly $225 a pound), according to the research team’s findings.

The gills are boiled along with other fish products in a soup that is promoted as a cure for anything from chickenpox to cancer. “I call it endangered species soup,” said Mr. Heinrichs, who led the research.

The researchers note that the gills had not previously been prescribed in traditional Chinese medicine, and many of its practitioners conceded in interviews for the study that gill rakers were not effective in treating illness and that many alternatives were available. The rising popularity of the ingredient seems to be the result of traders’ efforts to create a market, the report’s authors concluded.

The growth in demand has been devastating for populations of both rays — all the more so because these creatures reproduce very slowly.

A female manta ray will produce between 10 to 16 pups at best during her lifetime, far fewer than great white sharks, for example, which can produce that many in a single litter. And while great whites are protected under international conventions, manta and mobula rays are not, largely because the fishing pressures described in the new report are little understood by conservationists and the general public.

“The economics and the moral imperative are clear,” Peter Knights, executive director of WildAid, said in a statement. “We need an immediate moratorium on gill raker trade, and measures for complete protection to some populations and to reduce fishing pressure for others.”

A silver lining is that these creatures are also viewed as generators of millions of dollars in tourism revenue because divers and snorkelers travel from far and wide to observe them.

For the time being, however, this is not helping to curb the trade. And because of the extreme vulnerability of the manta and mobula rays, the race to save them is “an entire factor worse” than the race to save sharks, Mr. Heinrichs said.

As I’ve written here before, it took years of campaigning before shark sanctuaries and bans on shark fin possession began to materialize.

With manta and mobula rays, “we simply don’t have the time to go through years of raising public awareness before action is taken,” Mr. Heinrichs said. “The race to preserve these species is almost over before it even started.”