For the first time, a shortfin mako shark (Isurus oxyrinchus) in the Mediterranean has been successfully tagged and tracked, marking a milestone in the conservation of this critically endangered species. Known for their speed and sleek build, these apex predators help regulate prey populations, maintaining balance within marine food webs. But their populations have been devastated by overfishing, often as unintended bycatch in commercial fisheries.
The tagging was part of the White Shark Chase initiative, spearheaded by Francesco Ferretti, Virginia Tech assistant professor in the College of Natural Resources and Environment. The team’s focus had been white sharks, but the young mako was encountered unexpectedly during a summer 2023 research expedition, and the team decided to seize the rare opportunity. “During that research trip, we encountered a young shortfin mako shark by happenstance,” explained Brendan Shea, a Ph.D. student involved in the expedition. “We placed an electronic tag on it, which provides valuable information about its movements, helping us understand how to better conserve the population.”
The shark was tagged with a pop-off archival tag, a sophisticated electronic device designed to collect data on water temperature, depth, and ambient light levels. This information not only reveals the shark’s movements but also gives clues about its preferred habitats and behavior. The tag is designed to detach after a set period, or, if the shark dives deeper than 5,900 feet (about 1,800 meters). Once it pops off, it transmits the collected data via satellite to the researchers, providing a treasure trove of information about the young shark’s journey. “These tags give us valuable information about where these animals travel,” Shea explained. “This makes conserving them easier. We need to do more tagging, but this is a great starting point.”
Over the course of just 54 days, the tagged mako traveled more than 750 miles—a remarkable feat for a shark likely only one- or two-years-old. This data challenges the notion that protecting nursery areas alone is sufficient for safeguarding young sharks, pointing to the need for broader conservation measures that account for their wide-ranging movements. “Sharks play a crucial role in the health of our oceans,” said Shea. “A healthy ocean supports various human activities, so understanding and conserving shark populations benefits everyone.”
For the researchers, the data doesn’t just show distance traveled but provides a window into the shark’s three-dimensional movement — insights, they say, are essential for designing conservation strategies tailored to their behaviors and needs. “Understanding the three-dimensional movement of sharks helps us know how they connect different habitats and their role in the ecosystem,” Shea emphasized. “This data also informs us about the depths they occupy, which is vital for conservation efforts.” While the tagging of this single shark is a groundbreaking achievement, the team says this is just the beginning. Much more data is needed to fully grasp the scope of their movements and ecological importance. Still, it provides a strong foundation for future work.
The collaborative research effort included scientists from institutions worldwide, such as the Polytechnic University of Marche, Stanford University, Oregon State University, and Stazione Zoologica Anton Dohrn, among others. Funding came from organizations like The Explorers Club, Discovery Channel, and Sharkproject, highlighting the global interest in protecting these remarkable creatures.
