Intermittent‐flow respirometry is an experimental protocol for measuring oxygen consumption in aquatic organisms that utilizes the best features of closed (stop‐flow) and flow‐through respirometry while eliminating (or at least reducing) some of their inherent problems. By interspersing short periods of closed‐chamber oxygen consumption measurements with regular flush periods, accurate oxygen uptake rate measurements can be made without the accumulation of waste products, particularly carbon dioxide, which may confound results. Automating the procedure with easily available hardware and software further reduces error by allowing many measurements to be made over long periods thereby minimizing animal stress due to acclimation issues. This paper describes some of the fundamental principles that need to be considered when designing and carrying out automated intermittent‐flow respirometry (e.g. chamber size, flush rate, flush time, chamber mixing, measurement periods and temperature control). Finally, recent advances in oxygen probe technology and open source automation software will be discussed in the context of assembling relatively low cost and reliable measurement systems.

Marine ecosystems provide essential resources and services, with fishes being of prime socio-economic importance. There are alarming global trends of excessive exploitation and habitat degradation of marine fishes, with most commercial stocks either overfished or nearing capacity ( Pauly et al., 2002; FAO, 2014; Pauly and Zeller, 2016). Global climate change is also altering patterns of marine biodiversity, with more pronounced effects expected in the future ( Perry et al., 2005; IPCC, 2014; McNeil and Sasse, 2016). The consequences of over-exploitation, habitat degradation and global climate change are unknown, but there is legitimate concern about irreversible loss of fisheries resources and biodiversity, leading to reduced food security and even direct threats to ecosystem integrity ( Perry et al., 2005; Cheung et al., 2009; Sumaila et al., 2011; Duarte, 2014; Elliott et al., 2015; Pauly and Zeller, 2016). There is a need, therefore, to improve the scientific knowledge base underpinning advice on the sustainable management of marine fish biodiversity and fisheries resources.

The aim of the study was to investigate the distribution of net joint moments in the lower extremities during walking on high-heeled shoes compared with barefooted walking at identical speed. Fourteen female subjects walked at 4 km/h across three force platforms while they were filmed by five digital video cameras operating at 50 frames/second. Both barefooted walking and walking on high-heeled shoes (heel height: 9 cm) were recorded. Net joint moments were calculated by 3D inverse dynamics. EMG was recorded from eight leg muscles. The knee extensor moment peak in the first half of the stance phase was doubled when walking on high heels. The knee joint angle showed that high-heeled walking caused the subjects to flex the knee joint significantly more in the first half of the stance phase. In the frontal plane a significant increase was observed in the knee joint abductor moment and the hip joint abductor moment. Several EMG parameters increased significantly when walking on high-heels. The results indicate a large increase in bone-on-bone forces in the knee joint directly caused by the increased knee joint extensor moment during high-heeled walking, which may explain the observed higher incidence of osteoarthritis in the knee joint in women as compared with men.