Description: English: Japweed, or Japanese Wireweed (Sargassum muticum) floating freely on water. This species is highly invasive: it remains alive after being detached from rocks (for instance after a storm), and may reattach itself somewhere else after being carried away by water currents. Picture taken on Baleal, Peniche, Portugal. Date: 3 July 2009. Source: uploaded with the author's permission. Author: Graça Gaspar. Permission (
Reusing this file): uploaded with author's permission.