Largemouth Bass Stocking
Bass stocking is extremely popular with anglers but must be based on solid science to ensure it returns effective and efficient results for the fishery.
In 2007, the Florida Fish and Wildlife Conservation Commission (FWC) opened the Florida Bass Conservation Center (FBCC) at Richloam Hatchery. Stakeholders and biologists both considered maximizing the effectiveness of this outstanding facility as an important key to the success of the Black Bass Management Plan, which was implemented in 2011.
The FBCC was modernized to provide optimal production of Florida largemouth bass for stocking and as a research facility for bass conservation. Stocking bass as a management tool has been used to supplement poor recruitment (fish that reach harvestable size), create new fisheries in artificial reservoirs, restore a fishery after renovation, or re-establish a fishery after a major fish kill. FWC hatchery staff developed a new production technique to spawn bass out-of-season (in fall), so they can produce advanced-fingerlings (4-inch) ready to stock in early spring. In theory, stocking advanced-sized fingerlings early should promote greater growth and survival, due to more abundant prey and less stocking stress in cooler water.
Few studies have evaluated long-term survival of stocked fish, largely because the technology to track large numbers of hatchery fish has only been recently developed and remains costly. FWC management and research staffs agreed to conduct a replicated small-lake stocking study to determine survival of hatchery-reared advanced-fingerling largemouth bass and factors that affect success of this management tool.
The study includes 11 lakes each less than 200 acres throughout Florida. These lakes had a history of poor or limited largemouth bass recruitment. In early 2012, each lake was stocked with 50 hatchery-produced advanced-fingerling bass per acre. Each bass was micro-wire tagged with wires embedded in cheek musculature. Recaptured fish can be identified using a scanning wand.
Starting in spring 2013, a bass population estimate will be done on each test lake. Since hatchery bass were tagged, biologists can determine which fish were stocked and which fish were naturally (wild) produced. This will be repeated in spring 2014. Characteristics that improved survival, such as vegetation, water quality, water levels and bass densities, will guide FWC biologists in determining when and where to use this management tool – or not.
Lake Trafford, a 1,500-acre natural lake in Collier County, underwent a three-phase multi-year restoration. More than 75 percent of the lake bottom was dredged to remove organic sediments and re-establish desirable habitat. Historically, the lake experienced repeated massive fish kills caused by excessive algal blooms fueled by the thick muck.
Phase-1 involved removing more than 6 million cubic yards of sediments with a dredge. Phase-2 included planting 75,000 giant bulrush, 25,000 plugs of “Kissimmee grass,” an acre of Illinois pondweed and multiple test plots of eel grass. Phase-3 was largemouth bass stocking and evaluation. It began in 2010 with 166,000 genetically marked fingerling (1-2 inch) bass, followed by 40,000 wire-tagged advanced fingerlings (4-5 inch) in June 2010. In March 2011, 50,000 more advanced fingerling largemouth bass were stocked, and the next month 192,000 fingerling bass were added. Genetic markers will be used to identify both sizes of bass from the 2011 stocking.
Spring and fall samples over the following two years consistently included 40 to 50 percent hatchery-produced bass. These findings provide strong support for use of hatchery fish to expedite recovery of bass populations that have been impacted by natural or human influences, but the jury is still out about stocking in established fisheries to improve catch rates.
For more information, contact Barron Moody, 561-625-5127; Barron.Moody@MyFWC.com.