In five sampling campaigns between 2021 and 2023, surface sediments (0-2cm) were collected from one station in Isfjorden, Svalbard (depth ca. 4.5 m; "Station 5": 78°06'36.0''N, 14°21'00.00''E ± 30 m). The sampling was done on two separate days per sampling campaign, during polar night (8th and 11th December 2021, 20th and 21st January 2023), polar day spring (30th April and 2nd May 2022, and 27th and 29th April 2023), and polar day summer (29th June and 2nd July 2022). Sediments were sampled using an Ellrott grab (Moncada et al., 2024). The top 2 cm of sediment was subsampled for further analyses. Analysis of bulk sediment pigment content was done according to the method described in Meier et al (2021).