The decrease in crappie density at Melvern is more likely a result of several factors such as prolonged drought, low spawning production resulting from low water levels/lack of spring inflows, low forage/shad density, and negative effects resulting from the zebra mussel population.
While the Melvern blue cats do eat crappie as well as a variety of other fish species, this predation by the blue cat population is not responsible for the drop in crappie numbers.