This is data on continuous high temporal resolution (every 5min) logging of several environmental parameters inside an eelgrass meadow at Gåsholmen close to the Tjärnö Marine Laboratory, University of Gothenburg from 2019-2024. The coordinates are:  58.878775428313126, 11.13467707196515.
The loggers were attached to a sledge attached to a buoy, so the exact position did change by ca 100m over the course of several years, when being sligthly displaced in storms. The approximate depth of the loggers was 1.5m deep, depending on water level. We downloaded the data and calibrated the loggers approximately every 3 weeks, at which point we also made sure that the loggers were positioned in the meadow. This was always the case, but sometimes the loggers were predominantly in Ruppia spp, particularly in late summer, and at these occasion we moved the logger to a an area predominantly consisting of eelgrass - Zostera marina. 

Appropriate Hobo loggers were used to record this high-resolution data, and all had to be replaced at least once during this time-frame. Missing data either indicates periods when the loggers (as well as the eelgrass meadow) were completely covered by drifting algae, or when a logger broke while out in the field.

Fields in the data file zostera_timeseries_5min.csv are:

Date – date and time of reading (UTC+1)
Temp – temperature (degree Celsius)
Sal - salinity (psu)
pH - pH
DO - dissolved oxygen (mg/L)
Lux - light (lux).