Ecophysiological Plasticity of Desmarestia aculeata (Phaeophyceae) Present in an Arctic Fjord

The Arctic region has been affected by high temperatures, directly affecting the macroalgae living there. One of the macroalgae that inhabit this area is the species Desmarestia aculeata (Phaeophyceae), widely distributed in the North Atlantic. It is exposed to the high Arctic light regime and fluctuating salinity conditions from glacial and terrestrial run-off. Despite its abundance, little is known about D. aculeata and how environmental drivers will affect it in a future altered by climate change. D. aculeata was collected during the summer of 2019, in Kongsfjorden, Svalbard (78.9°N, 11.9°E) to investigate its physiological and biochemical responses to salinities of 34, 28, and 18, and daily cycles of irradiance (50-500 µmol photons/m**2/s) at 0ºC over 21 days. Photosynthetic parameters and high pigment concentrations show how this species has an effective acclimation. These manuscript shows the high plasticity of the specie D. aculeata, such that the species will probably be able to tolerate future changes in the Arctic fjord.