Distributional pattern of seagrasses in the Canary Islands (Central-East Atlantic Ocean)

Abstract

The present knowledge of the marine phanerogams of the Canary Islands is poorly documented. Earlier studies of the marine phytobenthos along the Canarian coasts provides little information on seagrass ecosystems and their distributional patterns. This contribution summarizes the available information about the three species reported for the islands: Cymodocea nodosa (Ucria) Ascherson, Halophila decipiens Ostenfeld and Zostera noltii Hornemann; and their distributional records is analized in relation with the main oceanographic and geomor- phological conditions. Cymodocea nodosa and Halophila decipiens are present in shallow subtidal areas on diverse mobile substrata, whereas Zostera noltii has been reported for intertidal communities in one eastern locality of Lanzarote Island, with historical records in Fuerteventura and Gran Canaria Islands. At present, the latter species is not found in any of the mentioned localities and probably its has disappeared due to anthropogenic activities (urban pollution, sediments disturbances). Most of the localities with seagrass communities are located in the eastern and southern coasts of the islands, always in sheltered areas, protected against Trade Winds. The vertical distribution of Cymodocea nodosa meadows ranges from (0.3) 2 to 35 m depth, whereas Halophila decipiens meadows are present between 6 to 40 m depth