Macroalgal fresh biomass was collected in the subtidal fringe level at Guovolesuolu in Porsangerfjorden in July 2022. This dataset is part of a space-for-time comparison between low-Arctic Porsangerfjorden and high-Arctic Kongsfjorden. The aim was to document differences in macroalgal biomass and community composition between two Arctic fjord systems at different stages of cryosphere loss to understand how benthic vegetation in the high-Arctic will likely develop in the future.

The data contains fresh biomass data for a range of macroalgal taxa at the subtidal fringe level. Macroalgae were identified to the lowest taxonomic level possible. The taxonomic 'Class' of the species is provided, as well as a 'Category' that shows if the species is a kelp, or was found in the understory of the canopy-forming kelps. Within the taxon column there is a 'Fucus vesiculosus spiralis distichus', a 'Acrosiphonia Spongomorpha' and a 'Dictiosiphon Chordaria Stictyosiphon' value. Because these are field data, and the distinction between these species requires genetic lab work, the exact species identification is not possible.