| Tunicates | Botrylloides violaceus | 2000 | Definite | Established | Hull Fouling |
| Bryozoans | Bugulina simplex | 1913 | Definite | Established | Hull Fouling |
| Crustaceans-Crabs | Carcinus maenas | 1904 | Definite | Established | Dry Ballast, Hull Fouling, Natural Dispersal |
| Tunicates | Ciona intestinalis | 1882 | Definite | Established | Hull Fouling |
| Algae | Codium fragile ssp. Fragile | 1961 | Definite | Established | Oyster Accidental |
| Tunicates | Didemnum vexillum | 2003 | Definite | Established | Hull Fouling |
| Tunicates | Diplosoma listerianum | 2003 | Definite | Established | Hull Fouling |
| Algae | Gracilaria vermiculophylla | 2000 | Definite | Established | Hull Fouling, Natural Dispersal |
| Protozoans | Haplosporidium nelsoni* | 1985 | Definite | Established | Oyster Accidental |
| Crustaceans-Crabs | Hemigrapsus sanguineus | 1997 | Definite | Established | Hull Fouling, Natural Dispersal |
| Mollusks-Gastropods | Littorina littorea | 1901 | Definite | Established | Dry Ballast, Hull Fouling, Natural Dispersal |
| Mollusks-Bivalves | Ostrea edulis | 2007 | Definite | Established | Hull Fouling, Natural Dispersal |
| Protozoans | Perkinsus marinus* | 1995 | Definite | Established | Oyster Accidental |
| Fishes | Salmo trutta* | None | Definite | Established | Fisheries Intentional |
| Tunicates | Styela canopus | 1884 | Definite | Established | Hull Fouling |
| Tunicates | Styela clava | 1998 | Definite | Established | Hull Fouling |
| Mollusks-Bivalves | Teredo navalis | 1960 | Definite | Established | Hull Fouling |