Bones are big business, especially when they come from extinct species.

Over the past few years, a surprisingly regular market has emerged for bones of the massive marine mammal known as the Steller's sea cow (Hydrodamalis gigas). This oversized cousin to the manatee and dugong once lived along the outskirts of remote islands in the Russian Bering Sea—until Europeans hunted them into extinction nearly 250 years ago.

Manatees and dugongs are protected by several laws in the various countries in which they swim, but Steller’s sea cows died out long before any laws could have been enacted to protect them. Because of that, trade in their bones is actually fully legal under the Endangered Species Act and other international laws, much in the way that mammoth ivory is legal while elephant ivory is not.

Also like ivory, sea cow bones are often carved into intricate little statues or fashioned into expensive knife handles. Sometimes they are marketed as Steller’s sea cow bones. Other times they can be found for sale under nickname of “mermaid ivory.” (Walrus bones are also frequent sold as “mermaid bone.”)

Lorelei Crerar, an associate professor at George Mason University in Fairfax, Virginia, says she bought her first “mermaid ivory” carving around 2008. She has since collected about 200 more samples, including raw bones. Those bones led to a lot of questions—as well as some unexpected answers.

Tests of the mitochondrial DNA within those bones revealed some startling information. According to a paper Crerar co-authored in 2014 in the journal Biology Letters, many of the bones came from Alaska’s St. Lawrence Island, just south of the Bering Strait and more than 1,600 kilometers from where Steller’s sea cows were previously known to swim. This, according to the paper, means a previously unknown population of Steller’s sea cows lived around St. Lawrence Island more than a millennium ago. The bones were dated to between the years 800 and 920, around the same time as the Medieval Warm Period. The authors theorize that this population died off either due to a warming climate or by hunting by local Inuit people who may have arrived in the area around that time.

The animals no longer live on St. Lawrence Island, but the bones remain. Crerar says they are often dug up and used by the people employed in the scrimshaw industry. Carvings collected by Crerar depict whales, sea turtles, horses and even human skulls. Other bones are sold as-is for carving elsewhere. “The bones cost quite a bit to buy, especially if they are whole ribs,” Crerar says.

Crerar’s DNA tests also revealed something beyond the previously unknown sea cow population. According to a poster that she co-authored and presented last month at the Conference on the Biology of Marine Mammals*, a few of the samples she tested were not really “mermaid ivory.” They were actually gray whale (Eschrichtius robustus), pantropical spotted dolphin (Stenella attenuata) and white-beaked dolphin (Lagenorhynchus albirostris).

All of these species are not only still alive; they’re also safeguarded under the Marine Mammal Protection Act. The Yupik people of St. Lawrence Island legally hunt whales on a subsistence basis, but sale of products from these hunts is not allowed.

Crerar says the bones from other species may have just been a mistake. She doubts anyone was trying to pull a fast one by selling bones from anything other than the right species. “I am suspicious that the only bad bone I got came from a single sales person,” she admits. “But the natives on St. Lawrence seem to know a lot about the ribs they sell, so the people I usually buy from are very well taken care of.”

Still, the presence of whale and dolphin bones within the legal Steller’s sea cow market does present a quandary. Crerar’s poster concludes that government agencies such as the U.S. Fish and Wildlife Service and the National Marine Fisheries Service may need to start policing the “mermaid ivory” market in order to make sure that it is truly selling legal products.

That won’t help the already extinct Steller’s sea cow, of course, but it could be one more step to prevent other marine mammals from the same fate as their long-lost relative.


*Disclosure: I attended the Conference on the Biology of Marine Mammals on a fellowship from Compass, funded by the Packard Foundation. Reporting for this story was conducted after the conference.