| Taxonomic Group | Name | Year | Invasion Status | Population Status | Vectors |
|---|---|---|---|---|---|
| Crustaceans-Crabs | Carcinus maenas | 1903 | Definite | Established | Dry Ballast, Hull Fouling, Natural Dispersal |
| Cnidarians-Hydrozoans | Gonionemus vertens | 2000 | Definite | Established | Fisheries Accidental (not Oyster), Natural Dispersal, Oyster Accidental |
| Mollusks-Gastropods | Littorina littorea | 1996 | Definite | Established | Dry Ballast, Hull Fouling, Natural Dispersal |
| Tunicates | Styela clava | 2003 | Definite | Established | Hull Fouling |