Calibration of accelerometer transmitters to enable estimation of field metabolic rates in walleye

Abstract

Bioenergetic modelling is valuable for addressing many questions in animal ecology. However, applying these models to wild animals is limited by challenges with collecting in situ energetics data. To enable field applications, we conducted laboratory experiments using a swim tunnel respirometer on wild (n = 28) and hatchery-origin (n = 19) walleye (Sander vitreus) to calibrate acoustic accelerometer transmitters (InnovaSea V13A and V16AT) for estimating metabolic rate (ṀO2). Walleye (0.36–3.06 kg) underwent ramp-Ucrit swim trials (n = 70) across four temperatures (5–21◦ C). Using mixed effects models, we analyzed critical swimming speed (Ucrit), swimming speed, tailbeat frequency, and ṀO2 as functions of body mass, acceleration, sex, and water temperature. ṀO2 decreased with body mass and increased with higher swimming speeds, acceleration values, and water temperatures. Notably, ṀO2 increased more rapidly with acceleration at higher temperatures. No mass-specific sex differences were observed across measured parameters, and there were no differences in Ucrit or ṀO2 between control and tagged fish. These findings support the use of accelerometers to generate field estimates of energy expenditure in wild walleye.