Abiotic timeseries (T, S, O2, u, v, Chl a, Turb) obtained from the underwater fish observatory (UFO) in Kiel Fjord (March 2021 - May 2022)

The dataset contains temperature, salinity, oxygen, velocity, chlorophyll and turbidity data from the stationary underwater fish observatory (UFO). The stationary UFO was deployed at 54°20.4375'N, 10°10.4463'E from 2021/03/05 to 2022/05/18 about 50 m from the eastern shore of the Kiel Fjord, at a depth of 6 m. The abiotic sensor instrumentation consists of an upward looking acoustic Doppler current profiler (ADCP; Teledyne Workhorse Sentinel 1200 kHz), a pumped conductivity, temperature, and depth sonde (CTD; Sea Bird Scientific MicroCAT) and a combined fluorometer and turbidity sensor (Sea Bird Scientific ECO FLNTUS). All sensors were placed ~1.0 m above the seafloor. Time series data for ADCP, CTD and fluorometer were downloaded and preprocessed to obtain average estimates at a frequency of 1 h. To guarantee the high quality of the measurements and the data output, the sensors are regularly serviced. After each survey, back in the laboratories, the raw data collected at sea are first checked for consistency, and then processed and calibrated according to international standards. To verify and calibrate the T, S, O2, CHL, and Turb data, a vertical CTD profile was measured fortnightly close to the two UFO sites. Additional water samples were taken to determine oxygen levels using the Winkler method and to determine Chlorophyll levels to calibrate the fluorometer.