Woods Hole scientists study swordfish deep-sea navigation

Researchers from the Woods Hole Oceanographic Institution (WHOI) have released a study suggesting that swordfish may perform extreme deep dives to aid in open ocean navigation. While these fish typically hunt in the ocean twilight zone at depths of approximately 600 meters, they occasionally descend beyond 1,000 meters.

The study, published in Marine Biology, indicates that these rare dives may allow swordfish to sample different water masses and ocean features. This process could provide environmental cues necessary for navigating during long-distance migrations between regions such as Canada and the Caribbean.

To reach these conclusions, scientists analyzed movement data from 34 North Atlantic swordfish using satellite archival transmitting tags. Over 3,666 deployment days, researchers identified 39 instances of extreme dives. The research was conducted in partnership with NOAA’s Southeast Fisheries Science Center and the Massachusetts Division of Marine Fisheries.