Kelp forest biomass, species composition and depth distribution survey at Hansneset in Kongsfjorden, Svalbard

Macroalgal surveys were performed at Hansneset, Blomstrand in Kongsfjorden, Svalbard, from the infralittoral fringe down to 15 m depth in June – August 2021. This dataset is part of a time series currently spanning over 25 years and complements the studies conducted in 1996/98 (Hop et al., 2012) and 2012-14 (Bartsch et al., 2016). The aim was to document changes in Arctic kelp forest dynamics in an Arctic fjord system influenced by glacial melt by repeatedly sampling the same site in a standardized manner. As ocean temperatures in the Arctic have risen substantially and underwater light climate continuously deteriorated over this time period, alterations were observed in the seaweed community, especially kelps as major coastal foundation species. This Zenodo upload contains all datasets supporting the findings of the manuscript Düsedau et al. (2023) "Arctic kelp forest decline - a consequence of melting glaciers?".