Contrary to popular belief, Guntersville trophy bass are not pure Florida strain, according to DNA research conducted during the 2014 Bassmaster Classic at that northern Alabama fishery.
From a scientific standpoint, however, that really isn’t surprising. Between 1981 and 1994, an estimated 500,000 Florida bass were released into Guntersville, but few have been added since.
“The population, instead, consists largely of hybrid crosses,” said Dr. Eric Peatman, an associate professor in Auburn University’s School of Fisheries, Aquaculture, and Aquatic Sciences.
Eight-pound-plus fish are 52 percent Florida and 48 percent northern. That’s in keeping with the assessment of Gene Gilliland, B.A.S.S. National Conservation Director, who said that bass with 50 percent or more Florida genes have enhanced trophy potential. “Below that, and it’s no greater than for native fish,” he added.
Peatman and his team also found that the “lakewide average genetic composition” is about 70 percent northern and 30 percent Florida.
“Four to five-pound fish do not vary significantly from the lakewide average in their genetic make-up,” he explained. “However, seven-pound-plus fish show an increase in Florida percentage to 42 percent of their genome.”
These findings suggest that stocking Guntersville with Florida bass has been effective in shifting the genetic baseline of the population and that trophy-size fish are bunched around a rough 50:50 genetic split, said Peatman, adding that more samples are needed to reach definitive conclusions.
“One of the missing components in this analysis is age,” the scientist said, adding that multiple ages likely are represented among those samples of larger bass. “Ultimately, we want to know what is the genetic composition of the largest size fish within each year class, or what mix of Florida and northern alleles produces the fastest growing fish.”
The Alabama Department of Conservation and Natural Resources (ADCNR) will with this aspect during its spring sampling.
“A final component in the mix is obviously habitat,” Peatman said. “The best performing genotype in one reservoir is not necessarily the best genotype in a different reservoir with different environmental parameters. “So we have plans to include different reservoirs and habitats in the analysis in the coming year as well.”
All of this work is part of a statewide project funded by ADCNR to better understand the impacts of the state’s Florida bass stocking program on the quality of its bass fisheries.
“The Classic and other tournaments throughout the year in Alabama represent an excellent opportunity to take non-lethal DNA samples from larger bass brought in by anglers,” Peatman said.
“At the end of the day, the goal is to use these genetic tools to help ALDCNR make proactive stocking and management decisions to ensure the highest quality bass fisheries for our anglers for years to come.”
(This article appeared originally in B.A.S.S. Times.)