Why This Potentially Pregnant Great White Shark Is ‘Something Big’ for Science

Ever since a great white shark called Miss Costa was tagged in September 2016, she has traveled more than 8,100 miles along the East Coast — from Massachusetts south to the Carolinas and Florida, where she spends her summers.

But this year, the 12-foot-long, 1,700-pound shark did something unusual. Instead of taking her normal route, she made a sudden U-turn and headed for deeper waters.

Researchers are calling this change in Miss Costa’s travel pattern “something big.” Other female sharks they’ve observed have exhibited similar behavior when pregnant. Could Miss Costa, who is in her mid-to-late 20s, be expecting some toothy little bundles of joy?

Marine biologists are so excited about this possibility because they know very little about the mating and reproductive habits of great white sharks. In fact, a great white birth has never been observed in the wild.

“We’ve only tagged about half a dozen mature females in this part of the world,” Robert Hueter, chief science advisor for the nonprofit Ocearch, told WECT. “To see this pattern sort of repeat itself is very important data for us. It’s exciting to see this and be able to predict the life cycle of this species.”

Ocearch aims to collect critical scientific data for the tracking and biological studies of marine species, including great white and tiger sharks. When the dorsal fins of tagged sharks like Miss Costa break the surface of the water for at least 90 seconds, satellites receive a ping.

You can view each tagged shark’s travel patterns on the Ocearch website or its Shark Tracker app. And, according to Ocearch, the process of tagging the sharks causes them minimal distress but “some level of brief discomfort.”

Miss Costa, also known as @MissCostaShark, is likely to become as famous — or at least as popular on social media — as two other female great white sharks tracked by Ocearch: 

  • Lydia, who’s been tracked since 2013 with a tag that also records water temperature and depth, is the first great white ever recorded to swim all the way across the Atlantic Ocean. Her Twitter account @RockStarLydia has over 41,000 followers.
  • Katharine, who was also tagged in 2013, has traveled over 34,000 miles in the past five years. Her Twitter account @Shark_Katharine has 54,000 followers.

The Sex Lives of Great Whites

This much is known about the sex lives of great white sharks: Males have what’s known as a clasper — a pelvic fin – that they use to impregnate females. Although great whites have never been observed mating in the wild, based on the behavior of other sharks, researchers believe that males must first bite the females’ heads or pectoral fins to gain necessary leverage. Ouch! Cue the theme from “Jaws.”

Once impregnated, female great whites have a gestation period of 12 to 18 months. They are ovoviviparous, meaning that embryos develop in eggs and then hatch inside the mother’s uterus. The pups are born shortly thereafter. There are typically between two and 10 pups per litter.

A 2013 study of four pregnant great white sharks off the coast of Mexico discovered that during that long gestation period, females avoid males by following what the study’s author, marine biologist Michael Domeier, referred to as “an ambling path through the open ocean” — which sounds very similar to Miss Costa’s route.

When it was time to give birth, the sharks returned closer to the shoreline, which was no easy task. They had to swim across commercial shipping lanes, putting themselves in danger of collisions with vessels. Because of their small size — they’re about 5 feet long at birth — the pups, who spend their first few years along the coastline, are also at risk of being caught by fishing boats.

Sharks Should Be Afraid of Humans

While many people have a fear of sharks — galeophobia –  these predators,  especially pregnant females, have good reason to be much more afraid of humans.

In addition to being killed by ships and entangled in commercial fishing nets, the population of great white sharks is dwindling because they’ve been hunted for their fins and teeth for many years. And that’s truly scary, since these sharks play an essential role in the ecosystem. At the top of the marine food chain, great whites prey on the sick and weak, helping to stop diseases from spreading and keeping other fish healthy.

If she is indeed pregnant, here’s hoping Miss Costa eventually makes it safely back to the shoreline to have her pups. Although galeophobics might disagree, the more great white sharks, the better.

Photo credit: Elias Levy/Flickr


bob P
bob P5 months ago

Vert interesting thank you

Linda W
Linda Wallace5 months ago

I am glad that great whites are being studied. We need more knowledge.

Nicole Heindryckx
Nicole Heindryckx5 months ago

It would be very great if we indeed could figure out more about the great white shark. Most people still believe what they saw in the awful film JAWS. Since then, the animal has been hunted like a piece of vermin, the biggest danger on earth. It has been found that these animals are not at all dangerous to people, and that we should not fear them more than a grizzly bear or an elephant or lion. Just leave them alone, and they don't even look at you !!
It would be marvelous to see them giving birth to their babies, how and when they are being fed, etc... But of course these investigations must take place without hindering the animal. Women know that giving birth is not an easy and very private happening. So, when they can locate these females, filming must take place without disturbing or hindering the animal.
I would be exited to finally see a documentary showing the birth of babies (2 up to 10) of great whites. There still is so little known about sea living animals, be it fish or crabs, lobsters, etc.. that enlarging our knowledge of this part of the world, and even the biggest part of the world, and regretfully also specialized tele stations give so few documentaries, that I long to see more.
Before following the series of "Deadly Catch" I thought there were only 2 sort of crabs. Now I've seen at least 6/7 different ones. Watching Discovery Channel or BBC really is one of my favorite things to do, when my back is killing me%2

hELEN h5 months ago


Mark T
Mark T6 months ago


Janis K
Janis K6 months ago

Thanks for sharing.

Leo C
Leo C6 months ago

Thank you for posting!

Amanda M
Amanda McConnell6 months ago

Thanks for sharing

Amanda M
Amanda McConnell6 months ago

Thanks for sharing

Ruth S
Ruth S6 months ago