Byrnes, E. E., Lear, K. O., Morgan, D. L. et al. 2020. Respirometer in a box: development and use of a portable field respirometer for estimating oxygen consumption of large‐bodied fishes. Journal of Fish Biology 96(4), 1045-1050.

Respirometry has become the standard method for measuring the metabolic rate of fishes. Traditionally, respirometry has required the fish to be kept in captivity and tested under controlled conditions; however, many species do not readily adapt to captivity, and stress caused by transport and confinement in captivity can inflate metabolic estimates or even cause adverse health conditions and death. This study developed a portable, low‐cost field respirometer for measuring oxygen consumption rates of large‐bodied fishes. The respirometer performed well in laboratory tests and was used to measure the oxygen consumption rates (urn:x-wiley:00221112:media:jfb14287:jfb14287-math-0101 O2) of bull sharks Carcharhinus leucas (mean: 249.21 ± 58.10 mg O2 kg−1 h−1 at 27.05°C). Interspecific comparisons and assessments of oxygen degradation curves indicated that the respirometer provided reliable measurements of urn:x-wiley:00221112:media:jfb14287:jfb14287-math-0101 O2. This system presents a field‐based alternative to laboratory respirometers, opening opportunities for studies on species in remote localities, increasing the ability to validate physiological field studies.