Seaweed. Running stems produce regularly spaced, flattened feather-like fronds, which grow upwards. Side branchlets opposite in attachment to midrib, curving upwards and narrowing towards the tip.
Saline waterbeds from industrial ports to clean bays, headlands. Prefers temperatures >20°C but tolerates wide range of conditions. Grows from seashore to 35m in depth.
Originally cultivated as an aquarium plant. Regenerates from tiny fragments. Spread on boat anchors, fishing gear.
Highly invasive, forms dense underwater ‘meadows’, rapidly becoming dominant.
Nearly impossible to control once infestation is established, regrows from tiniest fragments. Fishing gear, boat anchors should be checked regularly.
Call the national pest and disease hotline on 0800 80 99 66
Caution: when using any herbicide or pesticide PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.