Characteristics of an Unexploited Smallmouth Bass Population in a Missouri Ozark Stream

Abstract

An unexploited population of smallmouth bass Micropterus dolomieui in a headwater stream in the Ozark Mountains of Missouri consisted of relatively slow-growing fish at a high density (138 fish at least 150 mm long per hectare). The population size structure had a considerable percentage of large fish (proportional stock density = 41; 100 [number of fish ≥280 mm long/ number of fish ≥180 mm long]) and condition was average (Wr = 83; 100 × weight of individual fish/mean weight at length) for smallmouth bass in an Ozark stream. Total annual mortality for fish of ages 3–7 was only 16%. Estimates of biomass (28.9 kg/hectare) and annual production (11.7 kg/hectare) for fish at least 150 mm long were greater than those reported for 10 similar streams. The data suggested that a good-quality, although perhaps speciality, fishery could be maintained with highly restrictive harvest regulations in a headwater Ozark stream.