Researchers tag first Mediterranean shortfin mako shark

Virginia Tech researchers successfully tagged a young shortfin mako shark in the Mediterranean during the summer of 2023, the first time that this has been done in the region.

These sharks are critically endangered not only in the Mediterranean but also globally.

The research team tagged the mako shark during a research expedition for the white shark in the region.

“During that research trip, we encountered a young shortfin mako shark by happenstance,” said Brendan Shea, a Ph.D. student in the 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 tag the team used is called a pop-off archival tag. It collects and stores data on water temperature, depth, and ambient light levels. This data helps the researchers estimate the shark's location and understand its movements. The tag detaches after a set period or if the shark dives too deep – more than 1,800 meters – and then transmits the data back to a satellite.

“These tags give us valuable information about where these animals travel,” Shea said. “This makes conserving them easier. We need to do more tagging, but this is a great starting point.”

The research, carried out as part of the White Shark Chase initiative led by Francesco Ferretti at Virginia Tech, was published recently in Frontiers in Marine Science.  

This collaborative effort included Jeremy Jenrette of Virginia Tech's Department of Fish and Wildlife Conservation, Chiara Gambardella of the Polytechnic University of Marche, Gambardella and Stefano Moro of Stazione Zoologica Anton Dohrn, Khaled Echwikhi of the High Institute of Applied Biology of Medenine at University of Gabes, Robert Schallert and Barbara Block of Stanford University, Schallert of Tag-a-Giant, and Taylor Chapple of Oregon State University’s Coastal Oregon Marine Experiment Station.

Funding was provided by The Explorers Club, Discovery Channel, Sharkproject, the Bertarelli Foundation, the Augmentum platform, and individual donors.

The young mako shark traveled more than 750 miles in 54 days, even though it was likely only 1 or 2 years old. This means that protecting nursery areas might not be enough because these young sharks travel so far.   

“Sharks play a crucial role in the health of our oceans,” Shea said. “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.”   

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