The Use of Radiotelemetry to Evaluate Survival, Behaviour, and Habitat Selection of Stocked Hatchery Largemouth Bass

Domestication affects of pellet-reared largemouth bass have been documented at the Florida Bass Conservation Center including; behavioral, anatomical, and health related alterations.  While studies have shown poor post-stocking survival rates of less than 3% for pellet-reared bass in Florida lakes, advancements in the culture process such as out-of-season spawning, transitioning to live prey, and a new healthy diet should increase survival.  A radio-telemetry study was conducted on Lake Carlton (Lake County, FL) in the spring of 2009 and 2010 to evaluate the short term behavior and survival of pellet-reared largemouth bass once stocked into the wild.  Wild juvenile bass were also radio-tagged to identify behavioral and survival differences between hatchery and wild largemouth bass.  In the first 30 days post stocking, hatchery bass (n=30) suffered 62% mortality compared to 18% experienced by the wild bass (n=20).  Of the 30 hatchery tagged bass, 47% were determined to have succumbed to predation and three were suspected to be bird predation.  Movement (average meters per day ± SE) was also significantly different between the wild (25.7 ± 10.2 m) and hatchery-reared bass (74.5 ± 16.1 m).  Surviving wild bass had significantly faster growth (1.7 ± 0.29 mm TL) in percent body weight gained per day in comparison with hatchery-reared bass (0.4 ± 0.19 mm TL).  Conclusions from this study indicate that pellet-reared largemouth bass continue to suffer from domestication affects, leading to lower fitness and higher predation.  Further research needs to be done to reduce domestication affects by conditioning them to predators prior to being stocked into the wild.