| Country | Locality | Introduced | Year | Qualitative Value | Ref. |
|---|---|---|---|---|---|
| Greece | Northern Aegean Sea | 1995 - 1995 | absent | 58367 | |
| Greece | Northern Aegean Sea | 1996 - 1996 | rare | 58367 | |
| Portugal | Óbidos Lagoon | 1993 - 1994 | rare | 74793 | |
| England and Wales (UK) | R1 - between Flamborough Head and Winterton | 1973 - 1995 | rare | 80786 | |
| England and Wales (UK) | R2 - east coast between Winterton & North Foreland | 1973 - 1995 | absent | 80786 | |
| England and Wales (UK) | R3 - between North Foreland & Portland Bill | 1973 - 1995 | rare | 80786 |