Mean coverage of dominant algal species in Porsangerfjorden

Surveys were performed of %coverage of dominant macroalgal species at Harvika, Holmfjord and Veineset in Porsangerfjorden, northern Norway, between 2 m and 19 m depth in June 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 kelp forest depth extension 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. A coverage value (%) was assigned for the presence of each species in the visual close surrounding (~1-2 m radius) of the quadrat. In summary this generated a mean coverage value (%) for each species per replicate. The target replication was four per depth, but due to the depth corrections to chart datum and the measured height of the kelp canopy this resulted in n = 3-8 for each depth and species.