News Releases

Scientists trick nature, stock Lake Griffin with 200,000 unique largemouth bass

News Release

Wednesday, March 31, 2010

Media contact: John Benton, 352-732-1225 or 352-516-7105; Nick Trippel, 352-732-1225; Joy Hill, 352-258-3426

Throughout March, fisheries managers from the Florida Fish and Wildlife Conservation Commission (FWC) have been releasing more than 200,000 young Florida largemouth bass into Lake County's Lake Griffin. Scientists at the FWC's Florida Bass Conservation Center in Webster produced the juvenile bass, called fingerlings.

What's different about these fish is that managers raised them using a special technique that produces young bass large enough to be past a critical and vulnerable life stage before their release.

"This larger size should increase their ability to survive and ultimately increase the number of bass available for anglers to catch," said FBCC fisheries biologist Rick Stout.

The FWC plan calls for stocking Lake Griffin for the next two years using the same number of fingerling bass each year.  The fish stocked this year could reach 14 inches (the legal minimum size limit for anglers to keep) within two years.

Lake Griffin, located in Leesburg, has long suffered from low survival rates of juvenile bass produced naturally within the lake. This affects the overall bass population there, and FWC researchers hope that the larger, hatchery-reared bass released in the lake will help increase the number of large bass sought by anglers.

What makes this project unique is that this is the first time fisheries managers have stocked such a large number of bass so early in the spring.

"This is the result of coaxing the fish to reproduce in October, which is several months earlier than they would have spawned naturally," Stout said. "The young hatchery-raised bass are approximately 4 inches long when we release them, while most of the native bass have not even hatched yet.  That means a significant head start for this crop of fish."

Hatchery personnel did this by controlling water temperature and length of daylight in a series of tanks housing the brood bass. After the small bass hatched, managers reared them on a special diet in indoor tanks called raceways.

"The result is that fishery managers may have another tool to help revive the bass fishery of a lake," Stout said.

Genetics of the bass used in this process is another important component of this stocking project.  Scientists genetically tested the hatchery brood fish to ensure that they were pure, Florida-strain largemouth bass.

"Genetic testing also allows us to identify these fish throughout their lives as originating from the hatchery by testing just a small clip from a fin.  We no longer need to place a mark or tag on a fish to identify it. This simplifies testing how effective supplemental stocking is and is much less stressful to the fish than marking or tagging," said fishery biologist John Benton.  Scientists will be evaluating the success of this program through periodic samples and surveys of anglers.

For more information about this project, call John Benton or Nick Trippel at the FWC's Eustis Fisheries Laboratory at 352-732-1225.  See the July 2009 issue of "Fish Busters' Bulletin" at MyFWC.com/Fishing for more information about the FWC's bass-stocking program.



FWC Facts:
Johnson's seagrass (Halophila johnsonii) lives only in Florida, and is the only federally listed threatened marine plant species.

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