| Species Name | Country / Port | Port / Vicinity? | Detection Year |
|---|---|---|---|
| Styela clava | Netherlands / Rotterdam | port | 2014 - 2015 |
| Styela clava | Netherlands / Breskens | port | 2018 |
| Styela clava | Netherlands / Vlissingen | port | 2018 |
| Styela clava | Netherlands / Terneuzen | port | 2018 |