| Crustaceans-Crabs | Carcinus maenas | 1912 | Definite | Established | Ballast Water, Dry Ballast, Hull Fouling, Natural Dispersal |
| Algae | Codium fragile ssp. Fragile | 1995 | Definite | Established | Discarded Bait, Hull Fouling, Natural Dispersal |
| Algae | Colpomenia peregrina* | 2011 | Definite | Established | None |
| Crustaceans-Amphipods | Corophium volutator | 1975 | Definite | Established | Ballast Water, Dry Ballast |
| Tunicates | Didemnum vexillum | 2002 | Definite | Established | Fisheries Accidental (not Oyster), Hull Fouling |
| Annelids-Polychaetes | Hediste diversicolor | 2012 | Definite | Established | Ballast Water, Dry Ballast |
| Crustaceans-Crabs | Hemigrapsus sanguineus | 2001 | Definite | Established | Hull Fouling, Natural Dispersal |
| Mollusks-Gastropods | Littorina littorea | 1880 | Definite | Established | Dry Ballast, Hull Fouling, Natural Dispersal |
| Mollusks-Bivalves | Teredo navalis | 1960 | Definite | Established | Hull Fouling |