| Territory | Locality | Introduced | Year | Qualitative Value | Ref. |
|---|---|---|---|---|---|
| Portugal | Alcochete, Tagus Estuary | 1995 - 1996 | common | 74754 | |
| Portugal | Óbidos Lagoon | 1993 - 1994 | common | 74793 | |
| Portugal | Vila Franca de Xira, Tagus Estuary | 1995 - 1996 | very common | 74754 | |
| England and Wales (UK) | R1 - between Flamborough Head and Winterton (0) | 1973 - 1995 | very common | 80786 | |
| England and Wales (UK) | R1 - between Flamborough Head and Winterton (1) | 1973 - 1995 | common | 80786 | |
| England and Wales (UK) | R1 - between Flamborough Head and Winterton (2+) | 1973 - 1995 | common | 80786 | |
| England and Wales (UK) | R2 - between Winterton & North Foreland (0 group) | 1973 - 1995 | abundant | 80786 | |
| England and Wales (UK) | R2 - between Winterton & North Foreland (1 group) | 1973 - 1995 | very common | 80786 | |
| England and Wales (UK) | R2 - between Winterton & North Foreland (2 group) | 1973 - 1995 | common | 80786 | |
| England and Wales (UK) | R3 - between North Foreland & Portland Bill (0) | 1973 - 1995 | very common | 80786 | |
| England and Wales (UK) | R3 - between North Foreland & Portland Bill (1) | 1973 - 1995 | very common | 80786 | |
| England and Wales (UK) | R3 - between North Foreland & Portland Bill (2+) | 1973 - 1995 | common | 80786 |