Hookweed (Bonnemaisonia hamifera) is an invasive red seaweed species found in the coastal waters of the British Isles. Originally from the Pacific it was introduced to Europe through marine activities. Hookweed thrives in sheltered and moderately exposed environments, attaching to rocks or other seaweeds. Its life cycle includes a filamentous stage and a distinctive hook-like structure that allows it to cling to substrates, giving it its name. While it adds to biodiversity, its proliferation can impact native species and ecosystems by outcompeting them for resources. As such, it is monitored as part of efforts to manage marine invasive species in the British Isles.
