| Fishes | Acanthogobius flavimanus | 1972 | Definite | Established | Discarded Bait, Natural Dispersal |
| Crustaceans-Barnacles | Amphibalanus improvisus | 2011 | Definite | Established | Hull Fouling |
| Crustaceans-Amphipods | Ampithoe valida | 1975 | Definite | Established | Discarded Bait, Oyster Accidental |
| Mollusks-Bivalves | Arcuatula senhousia | 1971 | Definite | Established | Oyster Accidental |
| Tunicates | Ascidia zara | 2004 | Definite | Established | None |
| Mollusks-Gastropods | Batillaria attramentaria | 2007 | Definite | Established | Fisheries Accidental (not Oyster) |
| Tunicates | Botrylloides diegensis | 2009 | Definite | Established | Hull Fouling |
| Tunicates | Botrylloides violaceus | 2000 | Definite | Established | None |
| Tunicates | Botryllus schlosseri | 1969 | Definite | Established | Oyster Accidental |
| Bryozoans | Bugula neritina | 1969 | Definite | Established | Oyster Accidental |
| Bryozoans | Bugulina stolonifera | 2004 | Definite | Established | Oyster Accidental |
| Crustaceans-Amphipods | Caprella mutica | 2001 | Definite | Established | Oyster Accidental |
| Crustaceans-Crabs | Carcinus maenas | 1993 | Definite | Established | Discarded Bait, Natural Dispersal |
| Sponges | Chalinula loosanoffi* | 1975 | Definite | Established | Oyster Accidental |
| Tunicates | Ciona robusta | 2004 | Definite | Established | None |
| Tunicates | Ciona savignyi | 2004 | Definite | Established | Hull Fouling |
| Crustaceans-Amphipods | Corophium alienense | 1992 | Definite | Established | Unknown Vector |
| Bryozoans | Cryptosula pallasiana | 1975 | Definite | Established | Oyster Accidental |
| Cnidarians-Anthozoans | Diadumene lineata | 1956 | Definite | Established | Oyster Accidental |
| Tunicates | Didemnum vexillum | 2003 | Definite | Established | Oyster Accidental |
| Tunicates | Diplosoma listerianum | 1969 | Definite | Established | Oyster Accidental |
| Mollusks-Bivalves | Gemma gemma | 1974 | Definite | Established | Oyster Accidental |
| Algae | Gracilaria vermiculophylla | 2015 | Definite | Established | Habitat Restoration, Oyster Accidental |
| Crustaceans-Amphipods | Grandidierella japonica | 2002 | Definite | Established | Natural Dispersal, Oyster Accidental |
| Crustaceans-Isopods | Iais californica | 1972 | Definite | Established | None |
| Crustaceans-Amphipods | Jassa marmorata | 2001 | Definite | Established | Discarded Bait, Oyster Accidental |
| Crustaceans-Isopods | Limnoria quadripunctata | 1949 | Definite | Established | None |
| Annelids-Polychaetes | Megasyllis nipponica | 2011 | Definite | Established | Fisheries Accidental (not Oyster), Hull Fouling, Natural Dispersal |
| Crustaceans-Amphipods | Monocorophium acherusicum | 1971 | Definite | Established | Oyster Accidental |
| Crustaceans-Amphipods | Monocorophium insidiosum | 2011 | Definite | Established | Hull Fouling, Oyster Accidental |
| Crustaceans-Amphipods | Monocorophium uenoi | 1975 | Definite | Established | Oyster Accidental |
| Fishes | Morone saxatilis | 1890 | Definite | Established | Natural Dispersal |
| Mollusks-Bivalves | Mya arenaria | 1916 | Definite | Established | Fisheries Intentional |
| Mollusks-Gastropods | Myosotella myosotis | 1944 | Definite | Established | Cargo, Dry Ballast, Oyster Accidental |
| Mollusks-Bivalves | Mytilus galloprovincialis | 1990 | Definite | Established | Natural Dispersal |
| Crustaceans-Cumaceans | Nippoleucon hinumensis | 2011 | Definite | Established | Fisheries Accidental (not Oyster), Hull Fouling, Unknown Vector |
| Crustaceans-Isopods | Orthione griffenis | 2000 | Definite | Established | Discarded Bait, Natural Dispersal |
| Tunicates | Perophora japonica | 2012 | Definite | Established | Hull Fouling |
| Mollusks-Gastropods | Philine auriformis | 1994 | Definite | Established | Natural Dispersal, Unknown Vector |
| Mollusks-Gastropods | Philine orientalis | 1998 | Definite | Established | Ballast Water, Oyster Accidental, Unknown Vector |
| Annelids-Polychaetes | Pseudopolydora cf. kempi | 1971 | Definite | Established | Hull Fouling, Oyster Accidental |
| Annelids-Polychaetes | Pseudopolydora paucibranchiata | 1994 | Definite | Established | Hull Fouling, Oyster Accidental |
| Mollusks-Bivalves | Ruditapes philippinarum | 1949 | Definite | Established | Oyster Accidental |
| Bryozoans | Schizoporella japonica | 1975 | Definite | Established | Oyster Accidental |
| Bryozoans | Schizoporella variabilis | 2014 | Definite | Established | Hull Fouling |
| Crustaceans-Isopods | Sphaeroma quoianum | 1972 | Definite | Established | None |
| Annelids-Polychaetes | Streblospio benedicti | 1936 | Definite | Established | Oyster Accidental |
| Tunicates | Styela clava | 2000 | Definite | Established | Oyster Accidental |
| Protozoans | Trochammina hadai* | 1998 | Definite | Established | Oyster Accidental, Unknown Vector |
| Crustaceans-Shrimp | Upogebia major | 2018 | Definite | Established | Discarded Bait, Fisheries Accidental (not Oyster), Natural Dispersal |
| Bryozoans | Watersipora n. sp. | 2007 | Definite | Established | None |
| Bryozoans | Watersipora subatra* | 1995 | Definite | Established | None |