Monthly measurements of extracellular polymeric substances in a sub-Arctic fjord, Ramfjord in Tromsø, Norway between September 2020 and August 2021

Fjord water was collected on a monthly basis between November 2018-September 2019, and then again between February-August 2021 from 5m and 30m depth at two stations in a sub-Arctic fjord (Ramfjorden, Tromso, Norway) with a GoFlo (General Oceanics). Around 150ml was filtered onto 0.4 mum polycarbonate filters (Whatman). Following the colorimetric method by Dubois et al. (1956), a mixture of phenol and concentrated sulfuric acid was used to extract material from the filter to determine total carbohydrates in the sample. A spectrophotometer (UV-6300PC, VWR) was used to measure the absorbance of the solution at 485 nm. Since concentrations were too low to be calculated reliably with a standard curve against xanthan gum concentrations, relative EPS concentrations are depicted as “absorption at 485 nm”.