Effects of turbidity and risk of predation on habitat selection decisions by Fathead Minnow (Pimephales promelas)

Within aquatic ecosystems, turbid environments will have a significant impact upon predator-prey interactions if both the predator and their prey rely upon vision as their primary sense. Increasing water turbidity will reduce the probability of being detected by a predator, and once detected should provide prey with cover that is close and ubiquitous. We tested the extent that these features of a turbid environment will have in affecting the impact of predation risk on habitat quality using Fathead Minnow (Pimephales promelas) as the prey, and Yellow Perch (Perca flavescens) and Black Bullhead (Ameiurus melas) as visual and non-visual predators, respectively. Our experiments demonstrated a strong preference for turbid habitats in the absence of a predator. When a predator was present in a turbid habitat, the minnows reduced their use of this location but still preferred it to a clear habitat with no predator. These data suggest turbidity confers a benefit to feeding Fathead Minnow that more than compensates for the cost of predation risk.