Farewell, Java stingaree: Scientist declare the first marine fish extinction

Scientists know very little about the Java stingaree (Urolophus javanicus), which they haven’t spotted since a naturalist purchased this specimen from which he described the species at a fish market in Jakarta in 1862. Image courtesy of Edda Aßel, Museum für Naturkunde Berlin.

 

• In December 2023, scientists declared the Java stingaree (Urolophus javanicus), a species of stingray, extinct.
• It’s the first marine fish confirmed to have gone extinct due to human actions.
• Scientists know very little about the species, which they haven’t spotted since a naturalist purchased the specimen from which he described the species at a fish market in Jakarta in 1862.

In 1862, German naturalist Eduard von Martens was part of a multiyear expedition to what was known then as the Far East. That July, he found himself in a fish market in the city of Jakarta on the island of Java, then part of a Dutch colony. For a naturalist from temperate Germany, such a market must have been full of tropical wonders. Coming upon a strange little stingray, a popular delicacy in Indonesia, Martens purchased the dead fish.

Little did he know he’d be the only scientist ever to see it.

Fast-forward 161 years to December 2023, and that species, which Martens dubbed the Java stingaree or Urolophus javanicus, has been declared extinct. It’s never been recorded since 1862 and may have already been super rare when Martens purchased it. The extinction declaration comes after an extensive assessment for the IUCN Red List by researchers at Charles Darwin University (CDU) in Australia.

The Java stingaree, hardly a household name, is the first marine fish confirmed to have gone extinct due to human actions — and it took a century and a half for scientists to verify it.

A banded stingaree (Urolophus cruciatus), a genus-mate of the now extinct Java stingaree, photographed in Tasmania. Image courtesy of John Turnbull via Flickr (CC BY-NC-SA 2.0 Deed).

 “Extinction is forever, and unless we can secure populations of threatened marine species around the globe, the Java Stingaree will only be the tip of the iceberg,” Julia Constance, a Ph.D. candidate at CDU who led the assessment, told Mongabay in an email.

Scientists declared another fish extinct in 2020, the smooth handfish (Sympterichthys unipennis). But after a petition, the IUCN moved this fish back into its “data deficient” category a year later, meaning we still don’t know enough to say it’s extinct.

Stingarees are a type of stingray in the family Urolophidae that lives in the Indo-Pacific. They’re notable for having a single venomous spine on their tail and dwelling at the bottom of the sea. Constance said they also tend to be smaller than other stingrays and have a shorter tail.

We know the specimen Java stingaree is female, but little else about the species. We don’t know if the specimen, which is about the size of a dinner plate, is a juvenile or an adult. We don’t know the species’ range around Indonesia. We don’t know anything about its reproduction, though its closest relatives are slow breeders and therefore vulnerable to overfishing and other threats.

The Java stingaree was likely pushed to extinction by “unregulated fishing,” according to Constance, who said fishing pressure was so high that catches of many species were already dropping in the Javan Sea by the 1870s.

“The northern coast of Java, particularly Jakarta Bay where the species was known to occur, is also heavily industrialized, with extensive, long-term habitat loss and degradation,” she said. Given the fishing technology of the day, researchers assume the Java stingaree that von Martens described was caught within 40 kilometers (25 miles) of Jakarta.

With the help of local fishers, researchers have been keeping an eye out for this stingaree in catches for more than 20 years, with no luck.

“The Java Stingaree being named as extinct is a warning sign for everyone across the world that we must protect threatened marine species,” Peter Kyne, a senior research fellow at CDU who was also involved in the assessment, said via email.

Indonesia’s only other known stingaree, the Kai stingaree (U. kaianus), is currently considered data deficient but it could well be extinct too. It hasn’t been recorded since being described from two specimens collected in 1874 off the Kai Islands. The one bright side? It was collected from a depth of 236 meters (774 feet), so it may still be holding on out of sight. This is a pattern with stingarees: Another, the New Ireland stingaree (Spinilophus armatus), has also only been seen once by scientists, in 1841 near the island of New Guinea.

Not long ago, humans believed the seas were so plentiful and vast that our kind could never meaningfully affect them. Since then, we’ve pushed several marine species to extinction, including the Stellar’s sea cow (Hydrodamalis gigas), the great auk (Pinguinus impennis) and the Caribbean monk seal (Monachus tropicalis).

It’s also likely species have vanished without being scientifically cataloged. If von Martens hadn’t had enough money at the time to buy the Java stingaree at the market, it would never have been described. We’d be ignorant not only of its existence, but also its extinction.

“The extinction of the Java Stingaree likely happened long ago, and could have gone unnoticed,” Constance said. “Although a seemingly small and insignificant species, the Java Stingaree proves that our ocean’s resources are not inexhaustible.”

The group of jawed fish that includes sharks and rays first showed up on our planet around 400 million years ago. Yet these ancient beasts are facing new perils. According to a 2021 study in Nature, shark and ray populations have plunged globally by 71% in the last 50 years, largely due to fishing.

But it’s humans, as well, that can save what’s left. And protection, when implemented, can work.

“Fisheries are extremely important, both as a source of protein for a growing human population, and as a source of income,” Constance said, adding that people around the world need to manage fisheries sustainably and devote more resources to monitoring species that may be in trouble.

Citation:

Pacoureau, N., Rigby, C. L., Kyne, P. M., Sherley, R. B., Winker, H., Carlson, J. K., … Dulvy, N. K. (2021). Half a century of global decline in oceanic sharks and rays. Nature, 589(7843), 567-571. doi:10.1038/s41586-020-03173-9

 

 Source: https://news.mongabay.com/2023/12/farewell-java-stingaree-scientist-declare-the-first-marine-fish-extinction/