TROPHIC BASIS OF PRODUCTION OF STREAM-DWELLING SMALLMOUTH BASS, ROCK BASS, AND FLATHEAD CATFISH IN RELATION TO INVERTEBRATE BAIT HARVEST

Authors
Citation
Mj. Roell et Dj. Orth, TROPHIC BASIS OF PRODUCTION OF STREAM-DWELLING SMALLMOUTH BASS, ROCK BASS, AND FLATHEAD CATFISH IN RELATION TO INVERTEBRATE BAIT HARVEST, Transactions of the American Fisheries Society, 122(1), 1993, pp. 46-62
Citations number
74
Categorie Soggetti
Fisheries
ISSN journal
00028487
Volume
122
Issue
1
Year of publication
1993
Pages
46 - 62
Database
ISI
SICI code
0002-8487(1993)122:1<46:TBOPOS>2.0.ZU;2-J
Abstract
We quantified annual consumption and annual production of the principa l predatory fishes (smallmouth bass Micropterus dolomieu, rock bass Am bloplites rupestris, and flathead catfish Pylodictis olivaris) in a 62 -hectare pool of the New River, West Virginia, to evaluate the potenti al for competition among these species and people for crayfish (Cambar us sciotensis, Orconectes sanbornii sanbornii, and Orconectes virilis) and hellgrammite (Corydalus cornutus) resources. Production of smallm outh bass (3.21 g-m-2.year-1), rock bass (2.00 g.m-2. year-1), and fla thead catfish (0.56 g.m-2.year-1) was supported primarily by aquatic i nsects (age-0 and age-1 fishes) and crayfish (age-2 and older fishes). Hellgrammites were rarely eaten due to their secretive nature, and pr ey fishes were less numerous than crayfish in the diets and the enviro nment. Diet overlap among the three species was relatively high (Schoe ner's overlap index = 0.74-0.93); species composition and sizes of cra yfish eaten by the three fish species were similar. Smallmouth bass, r ock 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 hellgramm ite production. Peak consumption by cohorts of all three fish species occurred in August and September and was a function of survivorship, i ncreasing individual fish size, and temperature-controlled energetic d emand. Seasonal patterns of cohort production and biomass mimicked tre nds 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 fl athead catfish populations in the New River. The sizes of crayfish eat en by these fishes and harvested by people, the extent of use of crayf ish production by these fishes and people, the crayfish species compos ition in the diets of these fishes, the intensity of predation on cray fish in late summer, and diet overlap suggest that competition among N ew River fishes and people for the crayfish resource is intensive. Inc reases in bait harvest or efforts to improve the quality of New River sport fisheries would probably increase competition for the crayfish r esource.