University of Washington researchers tagging a swordfish
Steve Dougherty
Peter Gaube (wearing purple gloves) and Camrin Braun (far right) attach a satellite tag on a swordfish in August 2019 off the coast of Florida.

Researchers from the University of Washington are using high-tech tags to record the movements of swordfish — big, deep-water, migratory, open-ocean fish that are poorly studied — and get a window into the ocean depths they inhabit.

The researchers tagged five swordfish in late August off the coast of Miami: MaxSimoneAnthonyRex and Oliver. Their movements can now be viewed in near-real time. And although swordfish are a prized catch, these ones aren’t at higher risk, researchers say, since the website updates only every few hours and these fast-swimming fish spend most of their time far from shore.

This is the first time satellite position tags have successfully been placed on swordfish caught off the coast of the United States.

Earlier tags on swordfish relied on measurements of temperature and light to approximate the animal’s position, which resulted in errors greater than 60 miles (100 km). The new tags act together as a pair: One records detailed temperature, light and depth measurements as the fish is swimming, while the other beams back the precise location when the fish surfaces each day.

Oceanographer Peter Gaube and collaborator Camrin Braun, a UW assistant professor of aquatic and fishery sciences, have placed similar satellite tags on other ocean predators, including great white sharksblue sharkswhale sharks and manta rays.

“That’s why we’re so excited,” Braun said. “Swordfish are a particularly good platform to help us make observations in the deep ocean, while at the same time giving us a better understanding of why and how this predator makes a living.”

Read more at UW News »