| Tunicates | Botrylloides violaceus | 2005 | Definite | Established | Hull Fouling |
| Tunicates | Botryllus schlosseri | 2012 | Definite | Established | Hull Fouling, Oyster Accidental |
| Crustaceans-Crabs | Carcinus maenas | 2017 | Definite | Established | Natural Dispersal |
| Bryozoans | Cryptosula pallasiana | 1972 | Definite | Established | Hull Fouling, Oyster Accidental |
| Crustaceans-Amphipods | Grandidierella japonica | 1999 | Definite | Established | Hull Fouling, Oyster Accidental |
| Crustaceans-Amphipods | Monocorophium acherusicum | 1999 | Definite | Established | Fisheries Accidental (not Oyster), Hull Fouling, Natural Dispersal |
| Mollusks-Bivalves | Mya arenaria | 1999 | Definite | Established | Fisheries Intentional, Natural Dispersal |
| Crustaceans-Cumaceans | Nippoleucon hinumensis | 1999 | Definite | Established | Fisheries Accidental (not Oyster), Oyster Accidental |
| Mollusks-Bivalves | Nuttallia obscurata | 1993 | Definite | Established | Ballast Water, Natural Dispersal |
| Algae | Sargassum muticum | 1950 | Definite | Established | Oyster Accidental |