Cooperative Fish and Wildlife Research Units Program: Tennessee
Education, Research and Technical Assistance for Managing Our Natural Resources

Bettoli, P. W. 2005. The fundamental thermal niche of adult landlocked striped bass. Transactions of the American Fisheries Society 134:305-314.


Researchers have described the temperatures selected by landlocked striped bass Morone saxatilis in different locales throughout the U.S. However, seasonally low concentrations of dissolved oxygen (DO) in many systems prevented striped bass from using cool waters (< 22 0C) they may have preferred. In Melton Hill Reservoir, a 92-km long impoundment on the Clinch River in east Tennessee, fifteen adult striped bass were tagged with temperature-sensing radio tags and tracked for an average of 418 d in 1999-2000. Cold hypolimnetic discharges from an upstream dam and heated discharge from a steam-generating electric facility near the midpoint of this run-of-the-river reservoir provided a broad range of temperatures in most seasons and hypoxic habitats were uncommon, even during stratification. Mean temperatures occupied by striped bass varied seasonally (repeated-measures ANOVA; P < 0.0001) and were highest in summer (17.5 0C), intermediate in spring and fall (15.4 - 16.9 0C) and lowest in winter (13.0 0C). The mean and modal temperatures occupied during the growing season (May - October 1999) were 17.5 0C and 19.0 0C, respectively, and 30% of the observations were between 9 0C and 15 0C. These data indicate that the fundamental thermal niche of adult landlocked striped bass may be lower than literature estimates. These results also represent the first unbiased field estimates of the influence of season on the thermal ecology of adult striped bass. Finally, the thermal characteristics of habitats considered optimal in habitat suitability index models for adult land-locked striped bass (i.e., 18-24 0C) should be revised to include cooler waters.