Female sharks and shipwrecks go together


Shipwrecks provide valuable habitat for female sand tiger sharks

August 1, 2019 

Photos from divers help reveal shark trends

The initial findings of a citizen science project studying the behavior of sand tiger sharks are in: female sand tiger sharks love shipwrecks. It’s been less than one year since the North Carolina Aquariums launched the Spot a Shark USA citizen science program. Divers were asked to submit recent and older photos of sand tiger sharks they spotted, along with data detailing where and when the photo was taken. Behind the scenes, researchers identified the sharks from the spots on their sides (just like human fingerprints the spots are unique) and plotted the sharks’ location.

Female sharks and "site fidelity"

The data suggests that female sand tiger sharks exhibit “site fidelity”- returning to the same locations over time. In fact, some sand tiger sharks were photographed and re-photographed at the same or nearby shipwrecks off the coast of North Carolina over a period of time ranging from a few months to six years.

“This indicates shipwrecks are potentially critical habitats for sand tiger sharks and worthy of further research,” says Avery Paxton, lead researcher for the project. “Knowing these shipwrecks may be critical habitat could help facilitate conservation of sand tiger sharks, whose estimated population off the United States coast have declined by more than 75 percent.”

Sand tiger sharks are a highly migratory species. Researchers believe sand tiger sharks use the North Carolina shipwrecks as “rest stops” on their journey from New England to Florida. The new data is also lending evidence to another theory that suggests the shipwrecks may be even more valuable to sand tigers as key reproductive habitats or even year-round habitats. To learn more about the shark research program visit: spotasharkusa.com.

—Frank Graff 

 Frank Graff is a producer/reporter with UNC-TV, focusing on Sci NC, a broadcast and online science series.