Trophic Basis of Production of Stream-Dwelling Smallmouth Bass, Rock Bass, and Flathead Catfish in Relation to Invertebrate Bait Harvest

Abstract

Abstract We quantified annual consumption and annual production of the principal predatory fishes (smallmouth bass Micropterus dolomieu, rock bass Ambloplites rupestris, and flathead catfish Pylodictis olivaris) in a 62-hectare pool of the New River, West Virginia, to evaluate the potential for competition among these species and people for crayfish (Cambarus sciotensis, Orconectes sanbornii sanbornii, and Orconectes virilis) and hellgrammite (Corydalus cornutus) resources. Production of smallmouth bass (3.21 g·m−2·year−1), rock bass (2.00 g·m−2·year−1), and flathead catfish (0.56 g·m−2·year−1) was supported primarily by aquatic insects (age-0 and age-1 fishes) and crayfish (age-2 and older fishes). Hellgrammites were rarely eaten due to their secretive nature, and prey fishes were less numerous than crayfish in the diets and the environment. Diet overlap among the three species was relatively high (Schoener's overlap index = 0.74–0.93); species composition and sizes of crayfish eaten by the three fish sp...