To investigate the response of Fucus distichus and Saccharina latissima to local environmental conditions along the Woodfjorden gradient in Svalbard, field sampling was conducted in August 2024. Specimens of both species were collected at ten sampling stations distributed along the fjord. The intertidal brown alga Fucus distichus was found at six of the ten stations and was collected by hand during low tide. Meristematic apical tips were cut for further analysis. The subtidal kelp Saccharina latissima was present at nine of the ten stations. At each station, sporophytes of similar size were collected from a water depth of 5 ± 2 m using a plant rake (Plant Rake 19.000, according to Sigurd Olsen, KC Denmark, Silkeborg, Denmark). Circular discs of meristematic tissue (2 cm²) were cut from the basal blade approximately 10 cm above the stipe for further analysis. The maximum quantum yield of photosystem II (Fv/Fm) was determined using a pulse-amplitude-modulated fluorometer (Portable Chlorophyll Fluorometer PAM-2100, Heinz Walz GmbH, Effeltrich, Germany) after 5 min of dark acclimation (n = 7–11 per station and species). Subsequently, all tissue samples were dried in silica gel, which was replaced regularly to ensure complete desiccation. Pigment composition was analyzed by high-performance liquid chromatography (HPLC; Chromaster® system with chilled autosampler 5260, DAD detector 5430, and column oven 5310; VWR-Hitachi International GmbH, Darmstadt, Germany) (n = 5 per station and species). Total carbon and total nitrogen contents were determined using an elemental analyzer (Euro EA 3000 Elemental Analyzer, EuroVector S.P.A., Milan, Italy) (n = 5 per station and species).