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

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 (Schoenerˈs overlap index = 0.74–0.93); species composition and sizes of crayfish eaten by the three fish species were similar. Smallmouth bass, rock bass, and flathead catfish consumed 35, 31, and 10% of the annual production of age‐1 and age‐2 crayfish and less than 1, 13, and 1% of the annual production of age‐1 and age‐2 hellgrammites. A bait fishery harvested an additional 5% of crayfish production and 8% of hellgrammite production. Peak consumption by cohorts of all three fish species occurred in August and September and was a function of survivorship, increasing individual fish size, and temperature‐controlled energetic demand. Seasonal patterns of cohort production and biomass mimicked trends in consumption. Peak fish production rates in late September were a function of survivorship, increasing individual fish size, and high rates of prey consumption. Cohort biomass accretion exceeded attrition from mortality during most of the growing season, peaking in October. Crayfish are critical prey for the smallmouth bass, rock bass, and flathead catfish populations in the New River. The sizes ofcrayfish eaten by these fishes and harvested by people, the extent of use of crayfish production by these fishes and people, the crayfish species composition in the diets of these fishes, the intensity of predation on crayfish in late summer, and diet overlap suggest that competition among New River fishes and people for the crayfish resource is intensive. Increases in bait harvest or efforts to improve the quality of New River sport fisheries would probably increase competition for the crayfish resource.

Post-Release Attributes and Survival of Hatchery and Natural Fall Chinook Salmon in the Snake River; 2000-2001 Annual Report.

“…We used algorithms for consumption (Thornton and Lessem 1978), respiration, and egestion-excretion (Kitchell et al 1977) described in Roell and Orth (1993). We did not model gametic energy storage (G) in the bioenergetics simulations because reproductive energy storage in smallmouth bass is not well known (Roell and Orth 1993).…”

“…We did not model gametic energy storage (G) in the bioenergetics simulations because reproductive energy storage in smallmouth bass is not well known (Roell and Orth 1993). Smallmouth bass physiological parameters used were from Roell and Orth (1993) and Shuter and Post (1990; Appendix 3).…”

“…We did not model gametic energy storage (G) in the bioenergetics simulations because reproductive energy storage in smallmouth bass is not well known (Roell and Orth 1993). Smallmouth bass physiological parameters used were from Roell and Orth (1993) and Shuter and Post (1990; Appendix 3). We used estimated energy density values (calAg -1 ) from Cummins and Wuychuck (1971), Petersen and Ward (1999), Shuter and Post (1990), and Rondorf et al (1985;Appendix 4).…”

“…Ney (1993) suggests that the bioenergetics approach is based on a sound method that accounts for energy pathways, but that the model is susceptible to errors in the input parameters and internal functions. We used coefficients for the physiological rate equations from a model for adult largemouth bass Micropterus salmoides (Roell and Orth 1993) because Hanson et al (1997) advocated using physiological parameters from adult fish of similar species to model adult fish for which no parameters are available. Borrowing coefficients from similar species is common in bioenergetics modeling, however, this approach has been suggested as a weakness of bioenergetics modeling by Ney (1993).…”

Influence du compartiment trophique dans les réponses des populations de poissons aux variations artificielles de débit

“…Several independent studies on productivity of the New River, West Virginia, USA, were integrated into a model of energy flow through the community (ROELL and ORTH, 1994). Strong trophic links existed between three carnivorous fishes (smallmouth bass, rock bass, and flathead catfish) and crayfish, smaller fish, and aquatic insects (ROELL and ORTH, 1993). The habitats that support the insect productivity are areas with perceptible current.…”