Back in the summer of 2023, Virginia Tech scientists were on white shark research expedition in the Mediterranean when they spotted something in the water: a shortfin mako shark.
The species is critically endangered both in the Mediterranean Sea and globally, and faces ongoing threats, including overfishing. The team tagged the shark – the first time this has ever been done in the region.
"We encountered a young shortfin mako shark by happenstance,” explains Brendan Shea, a Ph.D. student in Virginia Tech's College of Natural Resources and Environment.
“We placed an electronic tag on it, which provides valuable information about its movements, helping us understand how to better conserve the population.”
The team used a pop-off archival tag, a sophisticated device that collects data on water temperature, depth and ambient light levels. This information allows researchers to estimate the shark’s location and track its movements. The tag detaches after a set period or if the shark dives beyond 1,800 metres, transmitting its findings to a satellite.
“These tags give us valuable information about where these animals travel,” Shea says. “This makes conserving them easier. We need to do more tagging, but this is a great starting point.”
The tagged mako shark covered over 750 miles in just 54 days, despite being only one or two years old. This extensive travel suggests that protecting nursery areas alone may not be sufficient to safeguard young sharks, say the researchers.
"Sharks play a crucial role in the health of our oceans,” Shea explains. “A healthy ocean supports various human activities, so understanding and conserving shark populations benefits everyone. Understanding the three-dimensional movement of sharks helps us know how they connect different habitats and their role in the ecosystem. This data also informs us about the depths they occupy, which is vital for conservation efforts.”
The study, part of the White Shark Chase initiative led by Francesco Ferretti at Virginia Tech, was published in Frontiers of Marine Science.
Main image: The research team successfully tagged a Mako shark for the first time in the region as part of another research project/Francesco Ferretti.
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