Stocked Bass Learn Survival Skills
Researchers experiment with new hatchery procedures to better prepare young largemouth bass for the perils of the wild.
As Florida's premier freshwater sport fish, the largemouth bass is the central figure in a black bass fishery that generates more than $1.25 billion annually for the state. Maintaining and improving this valuable resource is a continuing effort that relies in part on supplementing wild stocks with hatchery-raised bass.
The FWC's Fish and Wildlife Research Institute (FWRI) evaluates these stocking programs and researches ways to improve them. In recent studies, biologists from FWRI's Eustis Fisheries Research Laboratory collaborated with researchers at the Florida Bass Conservation Center, the FWC's fish hatchery in Webster, to address some of the challenges of introducing hatchery-raised young bass into the wild.
Researchers have found that stocked bass have difficulty adjusting from feed pellets at the hatchery to live prey in the wild. They also typically lack the predator avoidance and survival skills of wild fish.
Biologists documented this vulnerability in a study at Lake Carlton in the Harris Chain of Lakes (Lake County). They tracked young hatchery bass and wild bass with radio telemetry to compare their behaviors. The researchers found that hatchery bass tended to wander away from cover more often than wild bass. Failure to avoid predators, including birds, was apparent from the radio tags that turned up on shore under nests, in neighboring Lake Beauclair, and even inside a live double-crested cormorant. Findings also showed that neither wild nor hatchery bass showed a preference for specific vegetation for cover.
Now researchers are adding predators and live prey to hatchery ponds, conditioning young bass to forage and avoid predators before entering the wild. Early results from this study have been encouraging. Conditioned fish tend to outgrow and survive other hatchery bass, indicating both improved foraging and avoidance of predators.
Additional research is under way to evaluate other aspects of the hatchery and stocking process and ensure that survival rates for stocked bass continue to improve, keeping the largemouth bass abundant for Floridians and visiting anglers.