Biting into URI’s shark lab

 

A professor at the University of Rhode Island is working on research that he hopes will lead to a better understanding of the moving patterns of mako sharks, thereby effectively and properly controlling their population.

“When we talk about sharks, everybody thinks about shark attacks and white sharks and shark week, and that kind of thing,” Dr. Bradley Wetherbee of the Biology department said.

However, researchers like Wetherbee are more fascinated than afraid. Dr. Wetherbee works on understanding how to help better manage shark populations at a time of heavy fishing. Most sharks are not heavily fished, but mako sharks are because of their taste. This is causing the population to go on the decline. The goal of Dr. Wetherbee’s research is not just focused on the scientific understanding of the sharks, but also on how to better manage the shark populations for conservation.  

In order to understand how to manage a population in a sustainable way, researchers have to first understand where the fish go. The exact paths mako sharks swim, up until recently, has been widely unknown.

“There are just so many different entities involved. If you know that there is this many in a population and they reproduce this fast, then you can take this number out of the population,” said Dr. Wetherbee. “But if there’s so many question marks about how many there are, where they are going, who’s catching them, then people do not have that great of an idea of what’s going on.”

Dr. Wetherbee started as a Master’s student working on studying the digestive tracks of sharks before venturing out on his own. This propelled him into pursuing a doctorate where he studied sharks off the coast of Hawaii on a boat using acoustics to listen for them. Using acoustic technology was very limited, as it was labor intensive and you cannot track the sharks very far. Now, Dr. Wetherbee uses tracking devices and satellite technology to track the movement of the sharks over months at a time. This use of new technology has led to many new findings that are challenging the current view.

One of the findings is that mako sharks travel huge distances. One of the sharks travelled from Maryland and almost made it to Europe before being caught by fishermen. Another shark went from Maryland up to Canada and then down to South America and back up.

Amongst the work with mako sharks, Dr. Wetherbee and his colleagues also stumbled upon a tiger shark revelation. The current ideas of tiger sharks are that they “are supposed to be coastal animals.” If you look at their design, the way their fins are and their body shape and their head, they’re terribly designed for the open ocean,” Dr. Wetherbee said.

Because of this, his team decided to track the tiger sharks movements. They tagged the tiger sharks off the coast of Bermuda and spent three years tracking them. Their findings found that the tiger sharks consistently spent months in the open ocean, about half of their time was spent out there.

“If you’re this big, giant shark, why would you leave [the coral reef] and go out in the open ocean? What’s out there,” said Dr. Wetherbee as hopes to be able to answer this question in the future.

 

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