There have murmurs this spring about yellowfin tunas being caught by South Carolina offshore anglers. Not the behemoths of a few decades ago when South Carolina’s 241-pound, 12-ounce catch was made out of Charleston by Tommy Lewis, but much smaller ones, yellowfins that don’t even meet the 27-inch federal minimum size limit.
Still, any news about yellowfins being caught off the coast of South Carolina is good news considering the decades-long drought.
“We haven’t had any landed in the Governor’s Cup since 2007, that number has been zero. In 2002 in five events we had 450 or so landed. That’s a giant difference in abundance,” said Wallace Jenkins, a fisheries biologist with the S.C. Department of Natural Resources and program coordinator for the S.C. Governor’s Cup Billfishing Series.
Jenkins said DNR biologists have been trying to collect yellowfin tuna tissue samples for research purposes for five years and so far have only one sample.
Recreational anglers out of Oregon Inlet, N.C., are landing 30,000 yellowfins a year, but a decade ago they were landing 300,000 annually, Jenkins said. South Carolina longline boats have landed yellowfin, but they are being caught off the northern tip of the Bahamas, he added.
The 27-inch size limit doesn’t protect yellowfins to spawn even once. The yellowfin tuna is a highly migratory fish, making management (done by the International Commission for the Conservation of Atlantic Tunas, or ICCAT) difficult. There is a western Atlantic stock and an eastern Atlantic stock, and the two stocks mix.
Jenkins said purse seining (where fish of all sizes are gathered in a large net) that takes place on the west coast of Africa and northern part of South America affects the abundance of yellowfin tuna off the coast of the U.S.
Jenkins said he likes to explain that when you have a large population of fish that all niches are filled. But as the population dwindles, then the fish are only found in the optimum places, where there are upwellings, feedings and high concentrations of bait.
He said he has been told that yellowfins weren’t as abundant off South Carolina in the 1970s, and there aren’t records of yellowfin abundance in DNR’s database.
Jenkins said he is hopeful that the yellowfin population could be rebounding.
In the meantime, DNR is trying to make sure the same thing doesn’t happen with another important tuna species, the blackfin tuna. Jenkins said there are no management measures in place, no size limit, and even less is known about blackfins than yellowfins.
“Amy (Dukes, tournament coordinator for the Governor’s Cup and also a DNR biologist) has been meeting boats each afternoon to collect tissue and genetic samples so that we can better (understand) the blackfin population,” Jenkins said.
He said Dukes has collected more than 100 samples this spring, including tissue and fin clips, for DNR work.
“Hopefully, we’ll get ahead of the game before they disappear,” Jenkins said.