Samples for sinking mass flux of size-fractionated (>0.7µm and >10µm) Chlorophyll-a and Phaeopigments were collected with short-term drifting sediment traps between 75° and 85°N in the northern Barents Sea with R/V Kronprins Haakon in March 2021 as part of the Nansen Legacy project (cruise 2021703, Q1). High-density bottom water was collected at the station and filtered (Whatman GF/F 0.7µm), and then filled into the trap cylinders (KC Denmark, aspect ratio >6) prior to their deployment. Afterwards, the sediment traps were deployed with 2 cylinders at each depth (30m and 120 or 200m) for a duration between 12 to 39 hours. Depending on the sea ice conditions, the sediment traps were deployed in open water, anchored to a sea ice floe or within an ice lead. Upon retrieval, the content of the cylinders from each depth was pooled and stored at 4°C in dark until further analyses. Between 100-300ml were filtered onto 0.7µm GF/F filters (Whatman) for the analysis of Chla and Phaeopigments, depending on the amount of material in the traps. To quantify the contribution of larger cells, additional subsamples for Chla were filtered onto 10µm polycarbonate filters (Millipore). After filtration, both filters were immediately transferred to a tube with 100% methanol and stored between 12-24h at 4°C for pigment extraction. Size-fractionated Chla (0.7 and 10µm) was measured with a pre-calibrated Turner Triology photometer before and after acidification with 5% HCl. Chla and phaeopigments were calculated according to Holm-Hansen & Riemann, 1978. Holm-Hansen, Osmund, and Bo Riemann. “Chlorophyll a Determination: Improvements in Methodology.” Oikos 30 (1978). https://doi.org/10.2307/3543338.