Physiological acclimation of floating Macrocystis pyrifera to temperature and irradiance ensures long-term persistence at the sea surface at mid-latitudes

► Large abundances of floating algae are found in coastal waters at mid latitudes. ► After detachment positively buoyant algae float to the seasurface where UV-radiation and temperature are high. ► Floating kelp Macrocystis pyrifera were able to acclimate to the UV-radiation and temperature at the seasurface. ► The high acclimation potential of these floating algae converts them into efficient dispersal vehicles at mid latitudes.