Biological invasions (the movement of organisms beyond their natural range) have been widely documented in the marine environment and we know that there are about 60 established non-native marine species in UK waters. The 'Marine Aliens' programme is a UK-wide co-ordinated research programme to look at the impacts of a selection of non-native marine invaders on indigenous species and ecosystems.  
Funded by the Esmée Fairbairn Foundation.
Download the Identification Guide for Selected Marine Non-native Species
This is a PDF file. Please check you have Adobe Acrobat Reader installed. [View Identification Guide 8.5 Mb]
 
Wakame (Undaria pinnatifida) Wireweed (Sargassum muticum) Green sea fingers (Codium fragile subsp. tomentosoides) Chinese mitten crab (Eriocheir sinensis) Japanese skeleton shrimp (Caprella mutica) Leathery sea squirt (Styela clava) Colonial sea squirt (Perophora japonica)