Measurements of net ecosystem productivity (NEP) and calcification (NEC) from contemporary coral reefs provide a baseline for monitoring the impacts of future stressors like ocean acidification and sea-surface warming. However, separating secular trends from natural variability requires NEP and NEC records across a wide range of spatial and temporal scales. One promising way to make these measurements is with autonomous pH and O₂ sensors. Crucially, the accuracy of this approach relies on knowledge of the in situ ecosystem productivity quotient (Q), which indicates the moles of O₂ consumed per mole CO₂ produced. Using co-located measurements of total dissolved inorganic carbon (DIC), total alkalinity, and dissolved O₂, we empirically determined Q during a three-year field campaign on Tetiaroa Atoll, French Polynesia. Empirical values of daily net Q (−1.02 ≤ Q_net ≤ −0.47) frequently differed from both the canonical value of −1.45 for the ocean and the value of −1 often assumed for tropical reef ecosystems. Furthermore, Q changed on hourly timescales, and integrated daily values differed between days. We hypothesize that captive bubbles on the surfaces of coral, macroalgae and other substrates can explain these variations in Q, with other influential mechanisms being mixing between parcels of water, sedimentary denitrification, and ammonium-fueled primary productivity. Our findings, which are robust to changes in the model that is used to correct for advection and gas exchange, as well as changes in model parameters, suggest that future investigations of metabolism on reefs should be based on measurements of carbonate chemistry variability, rather than O₂ evolution. Otherwise, large biases in NEP and NEC could result (> 40%).

对当代珊瑚礁的净生态系统生产力（NEP）和钙化（NEC）的测量为监测未来压力源（如海洋酸化和海表变暖）的影响提供了基准。但是，要将长期趋势与自然变异区分开来，则需要在广泛的时空范围内进行NEP和NEC记录。进行这些测量的一种有前途的方法是使用自动pH和O ₂传感器。至关重要的是，这种方法的准确性取决于对原位生态系统生产力商（Q）的了解，它表示每生产1摩尔CO ₂消耗的O ₂摩尔数。使用总溶解无机碳（DIC），总碱度和溶解O _{2的共地测量}，我们在法属波利尼西亚的Tetiaroa Atoll进行了为期三年的野战期间，根据经验确定了Q。日净Q的经验值（-1.02≤Q_网 ≤-0.47）通常不同于海洋的标准值-1.45和热带珊瑚礁生态系统的-1值。此外，Q在每小时的时间尺度上发生变化，并且每天的综合每日值在几天之间有所不同。我们假设珊瑚，大型藻类和其他基质表面的俘获气泡可以解释Q值的这些变化，其他影响机制是水域之间混合，沉积物反硝化和以氨为燃料的初级生产力。我们的发现对用于校正对流和气体交换的模型变化以及模型参数的变化具有鲁棒性，表明未来对礁石代谢的研究应基于碳酸盐化学变异性的测量，而不是Ø ₂进化。否则，可能会导致NEP和NEC出现较大偏差（> 40％）。