Small Lakes Stocking Study

By Nick Trippel and James Kramer      

A live prey-reared fish collected one year post-stocking during sampling on Lake Orienta

Biologists determined a need to do a head-to-head stocking comparison of live prey-reared vs. pellet-reared advanced fingerling Florida Bass Micropterus floridanus.  Eight small lakes (<100 ha) were selected for this study. In February of 2015, 45,791pellet-reared fish were microwire tagged in the right cheek. In May 2015, 42,102 live-reared fish were microwire tagged in the left cheek.  Both groups were stocked at a rate of 124 fish/ha. It was determined that the cost to raise fish was $0.38/fish for pellet-rearing and $0.30/fish for live prey-rearing.

James Kramer sampling Trout Lake one year post-stocking

Population estimates for stocked fish at one year ranged from 0 to 259 fish remaining for pellet-reared fish and 0 to 175 fish remaining for live prey-reared fish. Survival of live prey-reared bass ranged from 0% to 1.8%, and survival of pellet-reared bass ranged from 0% to 2.6%. The percent contribution of pellet-reared fish ranged from 0 to 16% and contribution off live prey-reared fish ranged from 0 to 41%. Combined numbers for both treatments of stocked fish to the total bass population ranged from 0% in Crystal Lake to 47% in Hardee Lake 4. These results are for one year post-stocking, but if similar for year two, when fish recruit to the fishery, it appears that survival is similar between the two treatments.  It also appears that lake selection to stock may be more important than rearing technique at the hatchery. Managers should focus stocking efforts on lakes with low adult abundance, low recruitment, and abundant forage.