The underreported presence of the subtidal seagrass Cymodocea nodosa in rocky intertidal pools of the Canary Islands

During 2014, 21 patches of Cymodocea nodosa were found in intertidal pools in Fuerteventura (Canary Islands). Pool substratum was mixed sand and rock, but mostly dominated by stone bottoms. Most plants were established with fully exposed rhizomes, filling small fissures without sediment. During subsequent sampling surveys between 2016 and 2019, the presence of these patches was consistent over time in an environment normally considered extreme for most seagrasses. As far as we know, the presence of Cymodocea nodosa patches in intertidal areas has not been observed previously in the Canary Islands. If the presence of C. nodosa patches in these intertidal pools is stable over time, it raises new environmental management and conservation questions for this endangered species in the Canary Islands. In addition, due to the current regression of C. nodosa meadows, our observations represent an optimistic perspective that underline the need for specific monitoring plans for this ecosystem.