The opening day of the 57th Annual Big Rock Tournament on Monday was big with four blue marlins brought in to be weighed. But the tournament is not all about sport. In addition to raising money for charity, each fish caught at the event handed over to NC State’s College of Veterinary Medicine to provide valuable data about the fish population.
Jeff Buckel, a professor in the Department of Applied Ecology at NC State, said that the latter’s Center for Marine Sciences and Technology, known as CMAST, is providing the National Marine Fisheries Service with anal fin spine samples from blue marlins caught at the Big Rock Tournament.
“We send out an email and say, ‘What do you guys need?’” Buckel said.
The Department of Applied Ecology is primarily interested in studying the feeding ecology of the fish brought to the dock such as the blue marlin, dolphin fish—better known as mahi-mahi—yellowfin tuna and wahoo.
However, the researchers collect a variety of fish parts for research including the scales, ear bones and anal fin spines. The anal fin spines, Buckel said, have been the most widely used because they allow researchers to estimate a fish’s age.
“We take a cross-section of [the anal fin spines], and they are just like tree rings,” Buckel said. “The fish has high growth and low growth periods, and from those low growth periods you can see how many winters or seasons a fish has been through. You count up the number of rings and that gives you the estimate of the age.”
CMAST collects fish samples from many fishing tournaments and charter-boat trips along the Eastern seaboard which contribute to research being done in other parts of the world.
In addition to the anal fin spine samples, the center is currently collecting muscle samples from blue marlins to be tested for mercury levels as part of a data collecting project with the National Marine Fisheries Service.
Buckel said that even though the study has yet to be finalized, the data show that mercury levels in the water have decreased since the 1970s as a result of more stringent regulations on mercury emissions in North America.
“Blue marlins are really nice handlers of the environment because they have a large-scale migration range so they roam throughout the oceans and they’re also a top predator that builds up the mercury to a measureable level [as they eat prey], so that’s really been an interesting finding coming out to Big Rock,” Buckel said.
CMAST is also sending samples of tissue and ear bones from dolphin fish to the University of Southern Mississippi as part of a study on the genetic links between fish populations in the Gulf of Mexico, the Eastern and Western regions of the North Atlantic and the Mediterranean.
“If you saw genetic differences, that would suggest that over evolutionary time there hasn’t been much mixing which would tell us that the population stays relatively local,” Buckel said.
Also working out of CMAST is Kyle Farmer, a second-year student in NC State’s veterinary medicine program with a focus in zoological medicine.
“We’re looking at the different species of fish and assessing what their environment is like, basically what they’re eating, daily stressors like being caught, all of that influences their environment,” Farmer said. “We’re trying to get a broad range of samples so that we can get a baseline of what normal is [for the fish] so that if something happens, we can find out what caused it easier and try to fix it quicker.”
Farmer said he volunteered to be a part of the project because much of his curriculum as a veterinary medicine student is focused on the clinical side rather than the research side. Monday was Farmer’s first day of doing research.
“It benefits me a lot to get in and experience the research because I’ve never tried it,” Farmer said. “It may be something that I fall in love with but I don’t know that until I get in and try it so that’s what this is for me.”
