Researchers Tag 34 Sharks Off Florida’s Gulf Coast: ICYMI

SARASOTA, FL — Thirty-four sharks kicking around off Florida’s Gulf Coast are now contributing to science as they swim through their days thanks to a recent research cruise intended to advance understanding of the apex predators’ populations. The April 17-21 cruise was a joint effort conducted by scientists from Mote Marine Laboratory, The Nature Conservancy, and two graduate and 40 undergraduate students from Eckerd College and New College Florida.

During the multi-day cruise, the team managed to attach identification tags on 21 blacktip sharks. Ten of those sharks happened to be pregnant females, Mote announced Wednesday. Six bull sharks, three blacknose sharks and four tiger sharks were also tagged.

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Of the 34 sharks tagged, one blacktip and five of the bull sharks received acoustic tags that are designed to ping when the creatures swim by receivers placed underwater in bay passes. One bull and one tiger shark also received special satellite transmitters courtesy of TNC scientists. Those transmitters will enable scientists to keep up with the sharks’ movements in the Gulf, Mote said.

The cruise was conducted on the Florida Institute of Oceanography’s R/V Bellows. The ship was designed specifically to advance scientific knowledge about the shark species that are found in southwest Florida’s waters, Mote said.

“It’s amazing how many studies we supported in a five-day trip, while also giving two groups of college students an exciting, hands-on learning experience,” said Dr. Jayne Gardiner, assistant professor of biology at New College of Florida. “The group fitted sharks with advanced tags and collected data and samples to serve multiple projects at our institutions and elsewhere. Blood samples and ultrasound results will support studies of shark pregnancy by our colleagues at University of North Florida, and clips of fin tissue will support assessments of genetic diversity. Our catch, release and tagging efforts provided data for studies of habitat use.”

While only certain sharks species were tagged, others were captured and released as part of the research effort, Mote officials said. All told, 54 sharks were captured and released, which participants say is a potentially good sign for the Gulf Coast’s shark populations.

“The catch data add to Mote’s Center for Shark Research's database going back more than 25 years, examining the relative abundance of shark species in southwest Florida coastal waters,” said Dr. Robert Heuter, one of Mote’s senior scientists. “The relatively high catches last week are a good indicator of the resurgence of depleted shark populations following 25 years of fisheries management designed to achieve sustainability of these populations. Also, the conventional and electronic tagging will add to our knowledge of where these animals go, when, and what critical habitats they need to survive.”

Eckerd and New College students, their professors say, got a lesson that no classroom lecture can compare to.

“This trip was a once-in-a-lifetime opportunity for most of the students involved,” said Dr. Bill Szelistowski, Associate Professor of Marine Science and Biology at Eckerd College. “Afterward they told me it was amazing and incredible to see large sharks up close, participate in real research at sea and use the latest technology to reveal answers to mysteries about sharks and the ocean.”

As for the evidence found that indicates healthy shark populations along Florida’s coast, Hueter stressed it’s very good news.

“Healthy shark populations are good for a healthy ocean, and all of us, whether we live on the coast or not, need a healthy ocean to keep our planet flourishing.”

To find out more about Mote Marine’s research efforts, visit the Sarasota organization’s website.

Dr. Jayne Gardiner of New College of Florida (long-sleeved blue shirt) works with a tiger shark, accompanied by students and colleagues during a shark research cruise from April 17-21 including New College of Florida, Eckerd College, Mote Marine Laboratory and The Nature Conservancy. Credit New College of Florida/Chip Litherland.