The Effects of Predation on Populations of Etheostoma fonticola

A management strategy adopted to protect a federally protected benthic fish (Etheostoma fonticola) under low flow conditions is the removal of piscine predators (e.g., Micropterus salmoides).  However, habitats of E. fonticola include another potential predator (crayfish; Procambarus), which collectively are reported to be formidable predators of benthic fishes. Removal of a top predator that consumes both benthic fish and crayfish can produce a cascading effect and unintentionally increase rates of consumption on E. fonticola by removing top-down regulation of crayfish communities.  The purpose of this study was to test for synergistic effects in benthic fish predation by quantifying number of E. fonticola consumed by crayfish, bass, and crayfish-bass treatments in a laboratory setting among three temperature regimes (i.e., cool water, spring water, warm water).  Temperature regimes were selected to mimic natural habitat conditions under lower flow conditions during the winter and summer in order to account for temperature-dependent metabolic demands of the predators and prey.  With two of the three temperature regimes tested, study results suggest that crayfish and bass predation on E. fonticola is additive and not synergistic.