Fisheries & Oceans Canada, Institut Maurice-Lamontagne, Mont-Joli, Quebec, Canada.
Faculty of Land and Food Systems, & Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada.
J Fish Biol. 2021 May;98(5):1206-1216. doi: 10.1111/jfb.14650. Epub 2021 Jan 18.
This analysis shows good intentions in the selection of valid and precise oxygen uptake ( O ) measurements by retaining only slopes of declining dissolved oxygen level in a respirometer that have very high values of the coefficient of determination, r , are not always successful at excluding nonlinear slopes. Much worse, by potentially removing linear slopes that have low r only because of a low signal-to-noise ratio, this procedure can overestimate the calculation of standard metabolic rate (SMR) of the fish. To remedy this possibility, a few simple diagnostic tools are demonstrated to assess the appropriateness of a given minimum acceptable r , such as calculating the proportion of rejected O determinations, producing a histogram of the r values and a plot of r as a function of O . The authors offer solutions for cases when many linear slopes have low r . The least satisfactory but easiest to implement is lowering the minimum acceptable r . More satisfactory solutions involve processing (smoothing) the raw signal of dissolved oxygen as a function of time to improve the signal-to-noise ratio and the r s.
本分析通过仅保留呼吸计中溶解氧水平下降斜率中具有非常高决定系数 r 的那些斜率，显示出在选择有效且精确的耗氧量（O）测量方面的良好意图，但是并非总是能够成功排除非线性斜率。更糟糕的是，由于信噪比低，该程序可能会高估鱼类标准代谢率（SMR）的计算，从而潜在地去除 r 值较低的线性斜率。为了弥补这种可能性，演示了一些简单的诊断工具来评估给定最小可接受 r 的适当性，例如计算被拒绝的 O 测定的比例，生成 r 值的直方图以及 r 作为 O 的函数的图。作者为许多线性斜率 r 值较低的情况提供了解决方案。最不理想但最容易实现的解决方案是降低最小可接受 r。更令人满意的解决方案涉及根据时间对溶解氧的原始信号进行处理（平滑），以提高信噪比和 r 值。
