Quantification and Evaluation of Factors Influencing Largemouth Bass Predation of Stocked Advanced Fingerling Yellow Perch
Seth A. Lundgren, Casey W. Schoenebeck, Keith D. Koupal, Jared A. Lorensen & Caleb G.
Largemouth bass, of course, once again displaying their penchant to be generalist predators. Researchers spent two years studying the survival of stocked advanced fingerling yellow perch in 8 Nebraska lakes (16 total stockings). Tests showed that handling mortality during stocking was essentually zero, while bass consumption of stocked yellow perch ranged from 0 - 100% depending upon lake and year, but averaged 26.4% across all lakes and years. The highest number of perch consumed was always on the day of stocking, with only minimal consumption occurring beyond day 4. This sounds similar to the trout stocking truck scenario we always hear about in California, and is certainly in line with other studies showing bass predation on other similarly stocked fishes.
In lakes that had largemouth bass populations comprised mainly of smaller sized individuals, there was typically greater yellow perch mortality, suggesting that there is greater perch survival in lakes with bass populations of larger size structure. Other possible factors that could affect stocking success included timing of the stocking, with cooler water temps (earlier or later in the year) possibly helping to limit predation, as well as having an alternative and abundant food source for the bass to feed upon at the time of stocking, such as appropriately sized gizzard shad.