Steiner, Niko; Nilsen, Anne M; Franke, Kiara; Rößler, Leonard; Salvaitis, Dominykas; Rautenberger, Ralf; Bruckner, Christian; Buer, Nikolai; Jueterbock, Alexander; Bartsch, Inka (2026): Growth and biochemistry of Saccharina latissima sporophytes in response to gametophyte priming [dataset bundled publication]. PANGAEA, https://doi.org/10.1594/PANGAEA.996568

We examined the effect of gametophyte priming on early life stages of Saccharina latissima (gametophyte growth, sporophyte recruitment, juvenile sporophyte growth) and adult sporophytes harvested after growing for six months in mariculture (size and biomass, biochemical composition) in two experiments. Experiment 1: we primed S. latissima gametophytes (Lofoten 2023; 15°C clonal culture; n = 7) for 3 weeks at 0°C, 10°C, and 20°C and induced gametogenesis at 10°C for 2 weeks, during which we assessed relative gametophyte growth rates (from day 0 – 5), progression of gametogenesis, and sporophyte recruitment. Resulting sporophytes reared at 10°C were subjected to a 14-day temperature gradient treatment spanning 7 temperatures (0, 5, 10, 15, 20, 21.5, 23°C). We measured sporophyte growth (length and relative growth rates) after 7 and 14 days. Experiment 2: primed (0°C, 10°C, 20°C; 3 weeks) gametophytes (Lofoten 2023; 10°C mixed culture; n = 5) were sown on ropes and reared in a mariculture experiment (2 months hatchery, 4 months mariculture). Adult sporophytes were sampled and we measured growth (sporophyte length and width), total biomass (in fresh weight per m rope) and biochemical composition (C, N, mannitol, laminarin, and mineral composition). During the mariculture experiment, seawater temperature and nutrient composition was recorded at different time points. The mariculture field experiment took place at the hatchery of Polaralge AS (Sandhornøy, Norway; December - February 2024) and the deployment site of Lofoten Blue Harvest (Lilje Engla, Lofoten, Norway; 68°16'02.8N 15°06'14.8E; February – June 2024). The laboratory experiments of experiment 1 and the CN-analysis were carried out at the Alfred Wegener Institute in Bremerhaven, Germany; the mannitol analysis at the University of Rostock, Germany; the laminarin analysis at the MPI Bremen, Germany; and the mineral analysis at NIBIO Bodø, Norway.