Fertile drifting individuals of the invasive alien Sargassum muticum (Fucales, Phaeophyceae) reach the coasts of the Canary Islands (eastern Atlantic Ocean).
Individuals of the invasive alien seaweed Sargassum muticum were found drifting off the coasts of Lanzarote (Canary Islands). This species is native to the cold temperate northwestern Pacific but currently is widely distributed in the NE Pacific and the Atlantic. The closest known populations of Sargassum muticum to the Canary Islands are located in Morocco, at more than 600 km north of Lanzarote. All Canarian individuals presented numerous pedicellate air vesicles, and some of them had receptacles with mature conceptacles. Although there was no evidence of attached individuals in the area, the release of gametes, zygotes or germlings from fertile individuals could start the invasion processes. Surveys and monitoring programmes should be conducted to avoid population development. The rapid detection of individuals is essential to manage and eradicate colonising Sargassum and prevent it becoming invasive as it has in many other regions.