In shallow coastal systems, sediments are exposed to dramatic and complex variability in environmental conditions that influences sediment processes on short timescales. Sediment oxygen demand (SOD), or consumption of oxygen by sediment-dwelling organisms and chemical reactions within sediments, is one such process and an important metric of aquatic ecosystem functioning and health. The most common instruments used to measure SOD in situ are batch-style benthic chambers, which generally require long measurement periods to resolve fluxes and thus do not capture the high temporal variability in SOD that can be driven by dynamic coastal processes. These techniques also preclude linking changes in SOD through time to specific features of the sediment, for example, shifts in sediment faunal activities which can vary on short time scales and can also be affected by ambient oxygen concentrations. Here we present an in situ semi-flow through instrument to repeatedly measure SOD in discrete areas of sediment. The system isolates patches of sediment in replicate benthic chambers, and measures and records oxygen decrease for a short time before refreshing the overlying water in the chamber with water from the external environment. This results in a sawtooth pattern in which each tooth is an incubation, providing an automated method to produce direct measurements of in situ SOD that can be directly linked to an area of sediment and related to rapid shifts in environmental conditions.

中文翻译：

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一种原位底栖室系统，用于提高沉积物需氧量的时间和空间分辨率测量

在浅海沿海系统中，沉积物面临环境条件的剧烈而复杂的变化，这些变化会在短时间内影响沉积过程。沉积物需氧量（SOD），即沉积物生物体和沉积物内化学反应对氧气的消耗，就是这样一个过程，也是水生生态系统功能和健康的重要指标。用于原位测量 SOD 的最常见仪器是批量式底栖室，通常需要较长的测量周期来解析通量，因此无法捕获可由动态沿海过程驱动的 SOD 的高时间变化。这些技术还无法将 SOD 随时间的变化与沉积物的特定特征联系起来，例如沉积物动物活动的变化，这种变化可能在短时间内发生变化，也可能受到环境氧浓度的影响。在这里，我们提出了一种原位半流通式仪器，可重复测量沉积物离散区域中的 SOD。该系统在复制的海底室中隔离沉积物斑块，并测量和记录短时间内的氧气减少，然后用外部环境的水刷新室中的上覆水。这会产生锯齿图案，其中每颗牙齿都是一个孵化体，提供了一种自动化方法来直接测量原位 SOD，该测量可以直接与沉积物区域相关并与环境条件的快速变化相关。