As part of the KROP - Kongsfjorden Rijpfjorden Observatory Programme, UiT The Arctic University of Norway and The Scottish Association for Marine Science maintain a marine obervatory in the high-Arctic location Kongsfjorden, Svalbard, since 2002. The observatory consists of an array of CTDs, temperature loggers, ADCPs and a sediment trap, in addition to various other instruments or installations that change from year to year. This dataset cotains the temperature, salinity, density data of a Seabird SBE16p CTD with E(PAR) light and chlorophyll fluoresence auxiliary sensors which was located at 34m depth in the deployment year 2017-2018. The fluorescence sensor data is given as raw voltage due to fouling and calibration issues. It is only suitable to detect fluorescence peaks, not to compute actual chlorophyll concentrations. The equation to compute chlorophyll concentration is given in the variable attributes, use with care. E(PAR) data is not corrected for drift due to fouling during the deployment.