An autonomous bottom-transecting instrument for making long time-series measurements of phytopigment fluorescence and acoustically detectable sediment structure to abyssal depths

PI建议开发一种自主的底部横断面仪器，Rover II，能够对到达海底的新鲜植物碎屑进行长时间序列估计。此外，该仪器还将同时监测沉积物的结构特征，这些特征会影响沉积物群落活动的时空异质性，最终影响沉积物中生物地球化学过程测量的信噪比和分辨率。Rover II将能够对植物色素荧光进行非侵入性的时间序列测量，作为沉积物表面新鲜植物碎屑的指示器，同时对相同的沉积物进行声学成像，以提供结构特征(例如洞穴和动物)的三维轮廓。沉积物群落新陈代谢测量(例如沉积物群落耗氧量)加上二维氧成像研究，将在包括多达50个地点的相同沉积物横断面上进行，无需停靠、补给和数据下载。这一工具将解决的关键问题将有助于回答在生物地球化学循环背景下有关远洋-底栖生物耦合的重大问题。这些问题包括：1)到达海底的植物碎屑的质量和数量是什么，2)灌溉(非扩散输送)在测量沉积物中的矿化作用方面有多重要，以及3)新鲜碎屑到达海底会在沉积物群落中引起什么反应？

The PI proposes to develop an autonomous bottom-transecting instrument, ROVER II capable of making long time-series estimates of fresh phytodetritus arriving on the sea floor. In addition, this instrument will concurrently monitor the structural features of the sediment that influence spatial and temporal heterogeneity in sediment community activity, ultimately affecting the signal to noise ratio and resolution of measurements on biogeochemical processes in the sediments. ROVER II will be capable of conducting non-invasive time-series measurements of phytopigment fluorescence as an indicator of fresh phytodetritus on the sediment surface, while imaging the same sediments acoustically to provide 3-dimensional profiles of structural features (e.g. burrows and animals). Sediment community metabolism measurements (e.g. sediment community oxygen consumption) coupled with 2-dimensional oxygen imaging studies, will be conducted on the same sediments along transects including up to 50 sites without docking, recharging, and data download. The critical questions that will be addressed with this instrument will help answer significant questions regarding pelagic-benthic coupling in the context of biogeochemical cycling. These questions include: 1) what is the quality and quantity of phytodetritus reaching the sea floor, 2) how important is irrigation (nondiffusive transport) in measuring mineralization in sediments and 3) what responses are elicited in the sediment community by the arrival of fresh detritus on the sea floor?