Photosynthetic performances of two deep‐water canopy‐forming fucoid algae across a depth gradient: Interspecific variability and short‐term adaptation to the light environment

Deep-water canopy-forming algae Gongolaria montagnei var. compressa and Ericaria zosteroides (Fucales: Ochrophyta) co-exist in mixed populations, the first taxa dominating at upper limit of distribution (20 m) second lower (40 m). This depth pattern is consistent with photosynthetic performances both taxa, E. showing higher efficiency (α) light saturation (Ik) compensation (Ic) than G. compressa. Neither photosynthesis (Pmax) nor dark respiration showed any significant change species level. v. Pmax α 20 40 m, but did not follow same trend, although Ik Ic decreased this species, pointing to an increased capacity show photo-adaptation. Each maintained its Psat values when transplanted from where it was dominant secondary, case m m. These results point a better performance low-light conditions, information that can be used improve success restoration action plans.