Fish, sharks, whales, and pinnipeds have an incredible capacity to navigate the ocean and repeatedly find and return to the same places, even when they are thousands of miles away. Bluefin tuna, for instance, annually migrate from the cold waters of Canada past The Bahamas and into the Northern Gulf of Mexico to spawn. This navigational capacity helps ensure that marine animals are in the right place at the right time to feed, breed, and take refuge from predators.
However, this homing capacity can also stymie human-led efforts to mitigate depredation, property damage, or other forms of mischief (for example, Neil the Seal) from conflict animals using translocation (moving conflict animals to a distant location). For instance, in Scotland and in the Pacific Northwest, conservationists attempted to translocate harbor seals and sea lions that were depredating salmon at rivers and dams. Animals were moved distances of up to 200 miles away, only to have those individuals return to those same locations weeks later.
Bonefish & Tarpon Trust's Florida Keys Shark Depredation Project is a multi-year research effort triggered by increasing shark-angler interactions and their potential impact on the flats fishery. The focus of this research is on shark depredation hotspots in the Keys, including the Flamingo area of Everglades National Park, and finding effective, science-backed mitigation strategies.
Though BTT researchers haven't tried translocating a lemon shark to see if it would return to depredation hotspots, they have learned about the sharks' ability to find their way home during the recent cold spell that affected South Florida at the end of January and early February 2026. During that event, BTT researchers already had more than 55 lemon sharks in Flamingo fitted with acoustic transmitters, which allows BTT to track the sharks' movements locally. Additionally, thanks to Capt. Rob Fordyce, BTT had four sharks fitted with satellite tags that track their movements anywhere in the world they decide to go.
Shark activity in Florida Bay during and after the 2026 cold event. South Florida entered cold front conditions on January 30, 2026, represented by the vertical line. Shark activity is measured by the number of acoustic detections on receivers.
The number of acoustically tagged lemon sharks detected in Florida Bay during and after the 2026 cold event. All lemon sharks sampled in Florida Bay left during the cold event and then returned afterward.
What did the data gathered during the cold spell reveal? From the acoustic tags, the researchers saw when the sharks left and returned; the satellite tags revealed where they went. At the onset of the cold event, sharks started to evacuate Flamingo, and by February 3, all the tagged sharks were gone. Three days later, as waters started to warm, sharks began to trickle back into the system. By February 25, all the tagged lemon sharks had returned.
The four satellite tags revealed that these sharks traveled far from Flamingo. One shark traveled a round-trip distance of 225 miles to Key West, north to Cape Sable, then back to Flamingo over the course of 15 days. Swimming in the opposite direction, another satellite-tagged shark traveled 138 miles to the northern end of Biscayne Bay and back to Flamingo over 27 days. The third shark traveled north and west into the Gulf, totaling a 119-mile trip over a two-week period. And the fourth shark went south to the Gulf Stream and returned 22 days later.
The most fascinating finding from this event was that the sharks, despite traveling hundreds of miles, returned to the exact (or nearly the exact) location they had left weeks earlier. This homing behavior not only highlights how spectacular the navigational capacity of our marine fauna is, but, most importantly for BTT's efforts to determine science-based mitigation strategies, we have learned that the potential challenges to translocate conflict animals could be considerable.
Learn more about BTT's Florida Keys Shark Depredation Project.