Nia Dorsey
A Georgia Southern Professor has introduced a research that involves sharks and how they see their prey under different environmental circumstances by studying the psychology through their eyes. Her goal was to see how sharks and stingrays are viewing their prey and other predators.
Christine Bedore is an associate professor at Georgia Southern. She has a passion for learning about the dangerous sea animals living at the top of the food chain. She enjoys working with the organization, OCEARCH, a nonprofit organization that tags sharks to conduct research off the East Coast.
Bedore likes a focus on studying the eyes of sharks and stingrays, so she takes many pictures when onboard with OCEARCH.
“We get a bunch of eye measurements and bring that back to the lab and match it up with museum specimens,” she said. Bedore models the act of tracing the path of light through the eyes. She is able to examine how far a shark can see its prey, or another shark when it is put under different environmental conditions
Bedore also likes to study the stress levels of sharks and to achieve this, she takes blood samples to test their physiology in certain situations. Skin samples are also collected to measure bacteria and antibiotics that reside on the body. They then remove parasites and look at the health of the sharks.
She also works with shrimpers and wants to understand how sharks and stingrays act around shrimp boat equipment.
“We are interested in how sharks and stingrays act with the trawl gear,” she said. “Whenever a shrimp boat is actively fishing, they have nets they put down on the bottom of the ocean and tow them along and basically catch whatever is in the path of the net, which is what we call bycatch.”
The small fish caught in these nets usually act as bait that attracts sharks. The nets end up ripping. Bedore wants to produce a way or method that would deter predators from the gear. But her study is more focused on what happens when sharks and stingrays are caught with the bycatch.
“Part of what we’re doing is trying to understand how many sharks and stingrays are being caught by shrimpers,” she said. “What areas along the coast are they being caught, are they catching newborns or adults and how is that going to be significant for the environment?”
Bedore, who teaches biology and holds a Ph.D is fascinated with her studies on sharks and hopes to learn more about the top predators. She wants to conduct more research and expand on her passion of knowing how sharks and stingrays work and live.
“This is such an early project so we’re just trying to get an overall picture of what’s happening,” she said. “What we’ve figured out so far is that most of the species (of shark) caught as bycatch are some of the most reproductively successful species, and since they are putting out a lot of young, the impact on shark populations is probably pretty minimal.”
Trawl nets have an impact on stingrays, interestingly. Most trawl nets have devices that help prevent sea animals like sharks, turtles and others from getting stuck in them.
“What’s kind of interesting is that stingrays, because they’re flat, can turn sideways, so the turtle excluder devices don’t seem to work for the stingrays,” she said. “But stingrays tend to be pretty prolific, so they’re probably similar to some of the sharks we’re seeing that are caught in the net and there may be minimal impact.”
Stingrays are known to not have many children. They only birth about one or two a year. Because of this, scientists have trouble studying long term effects on them.
“Stingrays can also have some trauma from going through the net; they’re potentially towed for hours, and they have stingers that can get caught in the webbing so it can damage their tails,” she said.
Bedore continues to work with OCEARCH and during these times finds something fascinating though her research.
“The most interesting thing I’ve learned is how incredible it is to see people from so many different areas of life coming together for a common goal,” she said. “We get used to working with other scientists but we don’t often have the opportunity to work with these fishing groups and production teams. That’s a really cool learning experience.”