Scientists Seek To Learn More About Sharks

Mar 17, 2017

Off the coast of Hilton Head Island, the M/V OCEARCH sits stationary ready to catch sharks from twelve inches to twelve feet. The vessel is a temporary laboratory for scientists conducting research on the fish, from the way they see color to their mating habits. OCEARCH has done expeditions around the world, though this is the first time the organization has worked off the South Carolina or Georgia coast. They were pulled here by shark activity.

Male white shark named "Hilton" caught earlier this month aboard the M/V OCEARCH
Credit Tucker Adams / OCEARCH

Earlier this month, the M/V OCEARCH managed to bring on board their first male shark of the three week expedition -- they had pulled up three female sharks so far. The crew corralled the 1,300 pound white shark onto the platform as scientists readied their equipment to quickly snag blood samples, measure dorsal fins, and fit three tags including one for tracking.

Owner of the boat Chris Fischer said catching this shark was a big deal.  

"The largest mature male spot-tagged with the first full health assessment work up in north Atlantic history a 12.5 foot mature male and we are going to name it Hilton," Fischer said. 

Hilton is guided off of the platform of the research vessel and back into the Atlantic Ocean. A group of scientists hope to gain valuable information from the samples collected Bryan Frazier. He's a scientist with the South Carolina Department of Natural Resources studying where and when sharks migrate. Frazier puts a tracking device on the shark’s fin so he can follow him as he moves across the world.

Two of the tags scientists fit to caught sharks
Credit Cooper McKim/SC Public Radio

Frazier said, “We’ve had tag returns from Norwegian fleets, from Japanese fleets, from Mexican fleets. We’ve had sharks that we tagged in South Carolina go down to the Dominican Republic.”

"We get as many scientists together to learn as much as possible to create an abundant future for the ocean and we want everyone to be involved."

When and where the fish move depends partially on water temperature. The National Oceanic and Atmospheric Administration reports 2016 had the highest globally averaged sea surface temperature on record. Frazier said those warmer waters, “might have pushed tiger sharks north a little earlier than they would usually have been here.”

Some scientific studies have linked warmer water temperatures to stronger hurricanes. Hurricane Matthew in October 2016 caused millions of dollars of damage along the South Carolina coast.

Chris Fischer leading a tour of the vessel
Credit Cooper McKim/SC Public Radio

All the data Frazier and the other scientists on this boat collect is shared; that’s how OCEARCH works. Founder of the organization Chris Fischer says that’s a condition of the scientists using the boat free of charge to study marine life. Fischer calls it an “ocean first approach.”

Fischer said, “We get as many scientists together to learn as much as possible to create an abundant future for the ocean and we want everyone to be involved.”

Fischer bought the boat formerly used to catch crabs and altered a few things to enable it to lift and hold sharks that are several feet long and weigh thousands of pounds. OCEARCH has done 28 expeditions around the world and says data collected while on expeditions has and is currently contributing to research papers. Fischer funds the expeditions through corporate sponsors.

Professional image of the research vessel
Credit Provided by OCEARCH

In response to concerns that the publicly available tracking data may point commercial fisherman right to where the sharks are, Fischer says the tracking data isn’t that precise enough to allow poachers to pinpoint exact locations.

The University of North Florida has been working with OCEARCH for the past four years. Graduate student Clark Morgan is on the Lowcountry expedition off the coast of Hilton Head to study shark mating and reproductive cycles.

Morgan said female sharks are pregnant for a lot longer than humans.

"We believe that it is about eighteen month’s gestation period which is a very long time and these animals are coming out born at four and a half feet long," Morgan said. 

When a mature female shark is caught, he will conduct an ultrasound to see if the animal is pregnant. Typically, Morgan says female sharks carry between six and twelve pups at a time. He adds finding out where and when sharks mate and give birth is important so that those habitats are protected.

Close-up of a caught shark on the Lowcountry expedition
Credit Provided by OCEARCH

Christine Bedore is another scientist researching on the M/V OCEARCH. Bedore is an assistant professor at Georgia Southern University studying the sensory ecology of sharks, as well as other marine organisms. From the sharks caught on this vessel, she plans to study the dilation of the eyes in response to changing light.

Bedore said, “We want to measure how these sharks are adapting to light environments as they go to surface waters or deep waters where the light is more limited.”

During the more than 20 day long expedition in the waters off of the Georgia and South Carolina coast OCEARCH reports having collected samples from four sharks. The scientists say each one will produce a lot of data for them to begin analyzing.