Monthly measurements of size-fractionated Chlorophyll-a and phaeopigments in a sub-Arctic fjord, Ramfjord in Tromsø, Norway between September 2020 and August 2021

Fjord water was collected on a monthly basis between September 2020 and August 2021 from 5m and 30m depth in a sub-Arctic fjord (Ramfjorden, Tromso, Norway) with a GoFlo (General Oceanics). Water for total Chlorophyll-a and phaeopigment concentration (~300-500ml) was filtered in triplicates through a GFF filter (0.7mum, Whatman). In addition, to characterize the contribution of large phytoplankton to Chlorophyll-a concentrations, an additional sample was filtered over a 10µm polycarbonate filter (Whatman). Immediately after filtration, the filters were extracted in 100% methanol at 4°C and in dark between 12 – 24 h. Afterwards, the samples were measured with a pre-calibrated Turner Trilogy fluorometer before and after acidification with 5% HCl after (Parsons et al., 1984). In May, samples were measured with a pre-calibrated Turner Trilogy fluorometer.