Why Maine researchers are doing ultrasounds on pregnant sharks

Look, it’s well documented that humans are much bigger threats to sharks worldwide than vice versa, and that there are all sorts of rare calamities more likely to befall you than a shark attack — lightning strikes, tornadoes and Black Friday crowds kill more people every year than sharks, for instance.

But still, bothering potentially irritably pregnant tiger sharks seems like dangerous work.

The tiger shark is second only to the great white in terms of suspected attacks on humans, as infrequent as they may be. And these are the sharks that University of New England researchers are giving pregnancy ultrasounds to.

Same basic thing as when doctors give expectant human mothers ultrasounds, except the patients have much sharper teeth and don’t post the grainy pictures on their Facebook pages.

The success of this breakthrough approach means that scientists can begin studying the reproductive habits and biology of these animals without having to occasionally sacrifice them. Previously, efforts to learn enough about the creatures to ultimately help protect them involved killing some specimens to inspect their reproductive organs and see if they were carrying embryos, according to a UNE release.

This new ultrasound research, which the UNE team is doing alongside counterparts from the University of Miami, is taking place in the waters off Tiger Beach in the Bahamas, which, in case it wasn’t obvious based on the name, are heavily populated by tiger sharks.

“Using the same ultrasound imaging technology used on pregnant women, we discovered Tiger Beach was important for females of different life stages, and that a high proportion of tiger sharks were pregnant during winter months,” said James Sulikowski, a professor at UNE’s Department of Marine Science and something of a go-to local expert on sharks.

The researchers were able to attract the sharks by using chum specially made from pickles and ice cream. Kidding.

Anyway, their study was written up and published in the “Journal of Aquatic Biology,” and found that it’s likely the no-shark-fishing zone that protects Tiger Beach contributes to the larger local shark populations there compared to the rest of the Caribbean.

“Our data suggests that Tiger Beach may function as a refuge habitat for females to reach maturity as well as a gestation ground where pregnant females benefit from calm, warm waters year-round that help incubate the developing embryos and speed up gestation,” said study co-author Neil Hammerschlag, a research assistant professor at the Miami school, in a statement. “It is crucial for marine biologists to understand their behaviors to provide information for resource managers to effectively protect and manage them.”