Scientists Invent Device That Sends Out Baby-Shark Birth Announcements

"This is our holy grail."

Amanda Kooser
Freelance writer Amanda C. Kooser covers gadgets and tech news with a twist for CNET. When not wallowing in weird gear and iPad apps for cats, she can be found tinkering with her 1956 DeSoto.
Amanda Kooser
2 min read
A group of researchers leans over the ocean water from a boat. They're holding a pregnant tiger shark above the waves and inserting a tag into its cloacal opening.

Researchers insert a birth-alert tag into the cloacal opening of a pregnant tiger shark.

Tanya Houppermans/Blue Elements Imaging

Congratulations, it's a bunch of bouncing baby shark pups! Shark science is taking a big swim forward with an innovation device called a birth-alert tag, or BAT, that tracks where pregnant sharks have their babies. 

Knowing where and when sharks give birth could help with conservation and protection measures. "We've been trying to do this since we started studying sharks," Arizona State University marine biologist James Sulikowski said in a statement on Wednesday.  "This is our holy grail. We have really advanced shark science, 20, 30, 40 years." 

A small, egg-shaped birth-alert tag for sharks. It's mostly white with a black tip. It's sitting on an open hand and is smaller than the person's palm.
Enlarge Image
A small, egg-shaped birth-alert tag for sharks. It's mostly white with a black tip. It's sitting on an open hand and is smaller than the person's palm.

The birth-alert tag is a small device that goes along for the ride when a shark gives birth.

James Sulikowski

According to the International Union for Conservation of Nature -- keeper of the IUCN Red List of Threatened Species -- a 2021 study found nearly 36% of 536 assessed shark species are threatened with extinction. Overfishing and the demands of the shark fin trade are driving a lot of the pressure. Shark fins are used in medicinal preparations or as food. 

A paper published in Science Advances on Wednesday details the use of the satellite-based BAT device in pregnant sharks. Researchers capture a shark and then insert a BAT through the animal's cloacal opening (where the babies come out). The small, egg-shaped device hangs out in the shark until she gives birth. It then floats to the surface and transmits a birth announcement with the time and location.

The team successfully used the device in a tiger shark and a hammerhead, two sharks known for traveling across long distances. 

Scientists also learned something new about sand sharks, discovering they like to give birth in abandoned shipwrecks. "It was a total surprise," Sulikowski said. "For most shark species we have no idea where they give birth or how far they must travel to habitats that are essential to their survival." 

The research team sees the BAT playing a big role in shark conservation. "Once habitats are discovered," said ASU, efforts will be made to protect those areas, either by creating sanctuaries or expanding areas already set aside for this purpose."