LAUSR

AbstractReliable fish condition estimates help managers better understand ecosystem population dynamics. Therefore, our study objectives were to measure seasonal changes in percent dry weight and energy density (physiological-based measures of condition) of stream-dwelling Appalachian Brook Trout Salvelinus fontinalis, field-validate bioelectrical impedance analysis (BIA) models, and compare reliability of BIA and morphometric-based estimates of condition. Percent dry weight was highly correlated to energy density (R2 = 0.93; J/g wet weight = −1,803.5 + 286.43 ∙ [percent dry weight]), and the relationship was clearly different from those published previously for other salmonids. Significant seasonal changes in adult Brook Trout condition were observed and likely related to energy depletion from reproduction and changes in terrestrial invertebrate consumption. Adult percent dry weight peaked in early September and was lowest in February. Age-0 fish did not have large changes in measured condition between s...