Distribution, Population Characteristics, and Physical Habitat Associations of Black Bass (Micropterus) in the Lower Eleven Point River, Arkansas

Abstract

We report the longitudinal distribution and population characteristics of Micropterus dolomieu (Smallmouth Bass), M. salmoides (Largemouth Bass), and M. punctulatus (Spotted Bass) of the lower Eleven Point River of Arkansas. Smallmouth Bass were the most abundant species collected, followed by Largemouth Bass and Spotted Bass. Abundance of Smallmouth Bass was greatest upstream and declined significantly downstream; abundance of Spotted Bass was significantly greater downstream. Largemouth Bass were evenly distributed throughout the river. Associated with these species distribution trends were a downstream decline in stream slope and velocity, and an increase in the proportion of pools relative to riffles and runs. Proportional stock structures were similar and relatively low for each species (range = 22.9–32.3). Growth rates of Smallmouth Bass and Spotted Bass were high relative to other study populations, with age-3 fish reaching ≈300 mm total length. Diets of adult Smallmouth Bass and Spotted Bass were similar. Diets of Smallmouth Bass varied by season (increased feeding on insects during the summer months) and length group (transition of feeding on insects to fishes to crayfishes). Relative weight was greater for Largemouth Bass (Wr = 96) and Spotted Bass (95) than for Smallmouth Bass (89). Based on habitat, abundance, diet and condition factors, the Arkansas portion of the Eleven Point River contains a viable and balanced population of black bass.