title: Thermal stress resistance of the brown alga Fucus serratus along the North-Atlantic coast: acclimatization potential to climate change.
abstract: Seaweed-dominated communities are predicted to disappear south of 45° latitude on North-Atlantic rocky shores by 2200 because of climate change. The extent of predicted habitat loss, however, could be mitigated if the seaweeds' physiology is sufficiently plastic to rapidly acclimatize to the warmer temperatures. The main objectives of this study were to identify whether the thermal tolerance of the canopy-forming seaweed Fucus serratus is population-specific and where temperatures are likely to exceed its tolerance limits in the next 200 years. We measured the stress response of seaweed samples from four populations (Norway, Denmark, Brittany and Spain) to common-garden heat stress (20 °C-36 °C) in both photosynthetic performance and transcriptomic upregulation of heat shock protein genes. The two stress indicators did not correlate and likely measured different cellular components of the stress response, but both indicators revealed population-specific differences, suggesting ecotypic differentiation. Our results confirmed that thermal extremes will regularly reach physiologically stressful levels in Brittany (France) and further south by the end of the 22nd century. Although heat stress resilience in photosynthetic performance was higher at the species' southern distributional edge in Spain, the hsp expression pattern suggested that this edge-population experienced reduced fitness and limited responsiveness to further stressors. Thus, F. serratus may be unable to mitigate its predicted northward shift and may be at high risk to lose its center of genetic diversity and adaptability in Brittany (France). As it is an important intertidal key species, the disappearance of this seaweed will likely trigger major ecological changes in the entire associated ecosystem.
authors.affiliation: Faculty of Biosciences and Aquaculture, University of Nordland, 8049 Bodø, Norway. Electronic address: Alexander-Jueterbock@web.de.
authors.forename: Alexander
authors.initials: A
authors.lastname: Jueterbock
authors.affiliation: Faculty of Biosciences and Aquaculture, University of Nordland, 8049 Bodø, Norway.
authors.forename: Spyros
authors.initials: S
authors.lastname: Kollias
authors.affiliation: Faculty of Biosciences and Aquaculture, University of Nordland, 8049 Bodø, Norway.
authors.forename: Irina
authors.initials: I
authors.lastname: Smolina
authors.affiliation: Faculty of Biosciences and Aquaculture, University of Nordland, 8049 Bodø, Norway.
authors.forename: Jorge M O
authors.initials: JM
authors.lastname: Fernandes
authors.affiliation: Shoals Marine Laboratory, Cornell University, Portsmouth, NH 03801, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: Coyer
authors.affiliation: Marine Benthic Ecology and Evolution Group, Centre for Ecological and Evolutionary Studies, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
authors.forename: Jeanine L
authors.initials: JL
authors.lastname: Olsen
authors.affiliation: Faculty of Biosciences and Aquaculture, University of Nordland, 8049 Bodø, Norway.
authors.forename: Galice
authors.initials: G
authors.lastname: Hoarau
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D000704:Analysis of Variance; D001267:Atlantic Ocean; D057231:Climate Change; D017931:DNA Primers / Q000235:genetics; D005060:Europe; D044645:Fucus / Q000502:physiology*; D006360:Heat-Shock Proteins / Q000378:metabolism; D006358:Hot Temperature; D010788:Photosynthesis / Q000502:physiology; D058974:Phylogeography; D060888:Real-Time Polymerase Chain Reaction; D013045:Species Specificity; D013312:Stress, Physiological
chemical_list: D017931:DNA Primers; D006360:Heat-Shock Proteins
keywords: Global warming; Heat shock protein; Heat stress; Macroalgae; Photosynthetic performance