Data presented here were collected between November 2019 to September 2023 within the research unit DynaCom (Spatial community ecology in highly dynamic landscapes: From island biogeography to metaecosystems, https://uol.de/dynacom/ ) involving the Universities of Oldenburg, Göttingen, and Münster, the iDiv Leipzig and the Nationalpark Niedersächsisches Wattenmeer. Experimental islands and saltmarsh enclosed plots were established in the back-barrier tidal flat and in the saltmarsh zone of the island of Spiekeroog (Germany). A recording current meter (RCM; SEAGUARD® Recording Current Meter, Aanderaa Data Instruments AS, Bergen/Norway) was installed in the back-barrier tidal flat near the experimental islands. The sensor was bottom-mounted in a shallow tidal creek (0.59 m NHN) using a steel girder buried in the sediment, which caused the sensor to be exposed during low tide. All low-tide data have been removed from the dataset. The system was equipped with a ZPulse Doppler Current Sensor (DCS), a conductivity sensor, an oxygen optode, and two analogue sensors for chlorophyll-a and turbidity (16445). All sensors were pre-calibrated by the manufacturer. Recorded data were internally logged until readout with the SeaGuard Studio software (V1.5.23). Salinity was derived in the SeaGuard Studio software using temperature-dependent, nonlinear seawater conductivity compensation following the Practical Salinity Scale (PSS-78). Subsequent data processing was done using MATLAB (R2024b). Turbidity and chlorophyll-a data were excluded from the final dataset, as the recorded signals show implausible values and did not pass quality-control criteria. Post-processing and quality control included (a) the removal of low tide data, data covering maintenance activities, and data affected by biofouling, (b) the removal of implausible values, c) an outlier detection using the Hampel filter method, and (d) visual checks. Identified outlier were removed and synchronously removed across all associated parameters of the respective sensor.

Due to a sensor malfunction, the instrument was sent to the manufacturer in 2022, where it was repaired and serviced before being redeployed in the field.