The invasive brown alga Undaria pinnatifida (Harvey) Suringar, 1873 (Laminariales: Alariaceae), spreads northwards in Europe.

The Asian kelp Undaria pinnatifida (Harvey) Suringar 1873 was found for the first time in Belfast Lough, Northern Ireland during 2012 and was probably established in 2013. This currently is the most northern locality in Europe. The recent expansion around Britain is likely to continue with further colonisation in Ireland and extension to Scotland. Conditions are suitable for colonisation of Celtic, North and perhaps Norwegian Sea coasts, where it is likely to become an important fouling organism on marinas, aquaculture equipment, and other structures. Its preponderance on marina and other pontoons suggests artificial structures are its preferred initial sites of colonisation.