Auer, Felix; Ahmerkamp, Sören; Cueto, Jairo; Winter, Christian; Holtappels, Moritz: Oxygen consumption rate, organic carbon and grain size data for intertidal sediments and oxygen concentration of pore waters data of Spiekeroog Island North Beach, May 2022 to April 2023 [dataset]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.971357 (dataset in review)

The permeable sandy sediments of beach aquifers receive a high input of electron acceptors, such as oxygen (O2), as well as fresh organic matter through seawater infiltration, driving the biogeochemical turnover in the subterranean estuary. Here, we experimentally determined seasonal sedimentary O2 consumption rates of intertidal sediments along a transect in the seawater infiltration zone at Spiekeroog Island North Beach, Germany, and present the data together with measurements of organic carbon and grain sizes, oxygen concentration of pore waters and beach topography. The samples were taken down to 1 m depth during two-monthly sampling campaigns from May 2022 to April 2023. Preliminary investigations of O2 consumption rates took place in in March, June and August 2017. Sediment and porewater sampling procedures were carried out as described by Massmann et al. (2023). O2 consumption rates were determined in slurry incubations of the retrieved sediments using gas tight vials (Labco Exetainer® 12 ml) equipped with O2 sensor spots (Pyroscience, OXSP5). Incubations were carried out in the dark at in situ temperatures, and vials were mounted on a rotating wheel to mimic porewater advection. The sediment's total organic carbon content was determined in a CS analyser (Eltra CS 800). Additionally, the fine fraction of the sediment was washed out and the organic carbon content of the fine sediments was measured in a CHNSO analyser (Hekatech Euro EA). The grain size distribution of the sediments was detemined using dynamic image analysis (Sympatec QICPIC). The O2 concentration in the pore water along the transect was measured immediately after the sample was taken using a flow-through oxygen optode (Pyroscience, OXFTC). The data was collected to investigate the impact of seasonal inputs and filtration efficiency on the O2 consumption during seawater infiltration into the permeable sands of beach aquifers.