Growth and mortality of Ozark bass (Ambloplites constellatus) in streams of the Ozark Highlands

The Ozark bass (Ambloplites constellatus) is endemic to the Upper White River Basin, and a limited amount of information exists on the Ozark bass population, including growth and mortality characteristics. The purpose of this study was to determine growth and mortality of Ozark bass in the Upper White River Basin, compare growth of Ozark bass to other Ambloplites species, and compare growth and mortality of Ozark bass between sample sites. Sampling occurred in Crooked Creek and in the Lower Wilderness Area (LWA) of the Buffalo River, with multiple collections from each body of water. Sampling occurred during summer 2013 via electroshocking from a boat. Length and weight data were recorded while sampling, and fish ages were determined through otolith retrieval. Ozark bass exhibited similar growth patterns to Shadow bass (Ambloplites ariommus); however, Rock bass (Ambloplites rupestris) grew faster and larger. Growth of Ozark bass appeared to be similar between Crooked Creek and the LWA of the Buffalo River until 5 years of age. After age 5, the growth of fish collected from the LWA of the Buffalo River slowed compared to 5 and older fish collected from Crooked Creek. Ozark bass of the LWA of the Buffalo River had an overall greater mortality rate than those in Crooked Creek; however, one of two sites sampled on Crooked Creek had a comparable fish mortality rate to that measured in the LWA of the Buffalo River. Results indicated that size-selected mortality may have occurred in the LWA of the Buffalo River and at least one location sampled in Crooked Creek, possibly due to fishing mortality and angler popularity at the sites. Data collected in this study were part of a long-term attempt by the Arkansas Game and Fish Commission to gather baseline data on the Ozark bass population and to determine the efficacy of current harvest regulations for that species in the Upper White River Basin. Baseline data will be used in the future to determine whether local fish populations respond to climate change or other impacts to the watershed