URI_Research _Magazine_Momentum_Spring_2020_Melissa-McCarthy

“Most shark fisheries around the world have shown a pattern of boom and bust. The population can’t sustain heavy fishing and declines rapidly.”

- Bradley Wetherbee

“In the U.S. we’ve decided that these fisheries are going to be managed sustainably by law, which means that the number taken out must not be greater than the rate at which they are reproducing, so that the population doesn’t decline. With shark populations, that’s often not the case because they are so easily overfished and exploited.” Wetherbee’s research — tagging and tracking sharks — aids in managing the populations. To come up with appropriate management measures, scientists must know the species’ geographic boundaries, the interactions they have with fisheries, and the specific country territorial waters through which they swim. Information about where the males, females, and large and small sharks swim — all are fished differently – directly influences best scientific advice for practices to protect their populations. During the summer, Wetherbee conducts his research on shark movement and migration in Rhode Island waters and provides undergraduate students with inshore fishing experience and the offshore tagging of mako sharks. Given its seasonal weather, the Ocean State provides a narrow window of time for Wetherbee’s work, so he also heads to Mexico, Bermuda, the Bahamas, and the Cayman Islands to

pursue the longer shark seasons. He says in the last 10 years, he and his collaborators have tagged more than 100 sharks. Offshore, Wetherbee’s team attracts bites using a rod and reel with chum. Once on board the boat, the sharks calm down, allowing the researchers to attach a transmitter to the dorsal fin in less than five minutes before returning the sharks to the sea. The number of sharks being tracked via satellite depends on the time of year. At the height of the summer, Wetherbee figures satellites probably pick up as many as 10 mako sharks that are carrying transmitters. People can follow the sharks’ journeys through the tracking projects of Nova Southeastern University’s Guy Harvey Research Institute. Wetherbee has collaborated with the program for nearly two decades and serves as its assistant director. While this research provides insight into shark populations and their interactions with fisheries, Wetherbee says much of the cascading ecological aspects remain unknown. However, lions on the Serengeti in Africa and wolves in Yellowstone National Park offer insight to the enormous influence of top predators on ecosystems. If you remove apex

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