Concise review of the macroalgal species Pelvetia canaliculata (Linnaeus) Decaisne & Thuret

Abstract

AbstractPelvetia canaliculata (L.) Dcne. et Thur. is a marine brown macroalga within the Fucaceae (Fucales, Phaeophyceae, Ochrophyta) and the only species remaining in the monotypic genus Pelvetia. Abundant on sheltered rocky shores of the North-East Atlantic, Pelvetia forms a distinct horizontal band along the upper fringe in the intertidal, between maritime lichens and Fucus spp. Pelvetia canaliculata is a perennial species, characterized by dichotomously branching thalli 10–15 cm in length, forming narrow channels (“channelled wrack”). Distributed on the extreme upper shore, the species is exposed to atmospheric conditions for prolonged periods between spring high tides; photosynthesis recovers quickly, and fully, after water loss. Effective de-epoxidation of the xanthophyll cycle observed in P. canaliculata constitutes an important photoprotective mechanism in this species which receives high doses of solar radiation during tidal emersion. In comparison with other intertidal brown macroalgae, only few studies have investigated its chemical composition. Pelvetia typically presents high levels of sulphated polysaccharides, alginic acid, and polyphenols, associated with antioxidant and other biological activities. It accumulates high levels of mannitol and volemitol, two sugar alcohols considered to be involved in its tolerance to extended emersion. As a natural cation exchanger, Pelvetia biomass displays high biosorption capacities for toxic metals. Besides its slow growth rate and related small quantities of biomass, low protein content coupled with low degradability, have so far limited its potential for valorization.