| Protozoans | Bonamia ostreae* | 1994 | Definite | Established | Oyster Accidental |
| Tunicates | Botrylloides violaceus | 1998 | Definite | Established | Hull Fouling |
| Crustaceans-Amphipods | Caprella mutica | 2007 | Definite | Established | Hull Fouling |
| Crustaceans-Crabs | Carcinus maenas | 1907 | Definite | Established | Ballast Water, Hull Fouling, Natural Dispersal |
| Algae | Codium fragile ssp. Fragile | 1964 | Definite | Established | Discarded Bait, Fisheries Accidental (not Oyster), Hull Fouling, Oyster Accidental |
| Algae | Colpomenia peregrina* | 2010 | Definite | Established | Hull Fouling, Natural Dispersal |
| Platyhelminthes | Convoluta convoluta* | 1998 | Definite | Established | Ballast Water, Hull Fouling, Natural Dispersal |
| Platyhelminthes | Cryptocotyle lingua* | 1956 | Definite | Established | Dry Ballast, Fisheries Accidental (not Oyster), Fisheries Intentional, Hull Fouling, Natural Dispersal |
| Annelids-Polychaetes | Hediste diversicolor | 1963 | Definite | Established | Ballast Water, Dry Ballast |
| Mollusks-Gastropods | Littorina littorea | 1880 | Definite | Established | Dry Ballast, Hull Fouling, Natural Dispersal |
| Algae | Lomentaria orcadensis* | 1973 | Definite | Established | Hull Fouling |
| Bryozoans | Membranipora membranacea | 2007 | Definite | Established | Hull Fouling |
| Algae | Neopyropia yezoensis* | 2005 | Definite | Established | Hull Fouling |
| Arthropoda-Insects | Petrobius brevistylis* | 1964 | Definite | Established | Cargo, Dry Ballast |
| Crustaceans-Mysids | Praunus flexuosus | 2007 | Definite | Established | Ballast Water, Natural Dispersal |
| Tunicates | Styela clava | 1998 | Definite | Established | Hull Fouling |
| Mollusks-Bivalves | Teredo navalis | 1960 | Definite | Established | Hull Fouling |