The Effect of Multiple Techniques On Largemouth Bass Stocking Success

Largemouth bass are commonly stocked in Illinois lakes to supplement wild fish populations.   Despite these stocking efforts, largemouth bass populations often do not increase in abundance or size structure.  We have conducted a set of experiments examining long-term survival of stocked largemouth bass and a variety of stocking techniques that may increase the growth and survival of stocked fish.  Stocked largemouth bass experienced similar growth and survival as wild fish after stocking through the following spring.  Once stocked fish reach age 1, there is substantial mortality leading to poor survival and little contribution to the adult largemouth bass population.  When different sizes of largemouth bass were stocked in a set of four lakes, we observed no survival of small fingerlings (2-inch) and no advantage of stocking large or advanced fingerlings (6 or 8- inch) when compared to medium fingerlings (4-inch).  Fish raised in rearing ponds had significantly higher survival than those raised in raceways through the first year following stocking.  However, by the second fall, mortality was high and there was low contribution of stocked fish from either rearing technique to the adult largemouth bass population.  We also observed no differences in survival of largemouth bass stocked using point source stockings at the boat ramp compared to fish distributed throughout the lake and into habitat.  Future research will examine how acclimating fish to natural centrarchid prey may increase their foraging ability and may lead to enhanced growth and survival following stocking.