| Country | Locality | Introduced | Year | Qualitative Value | Ref. |
|---|---|---|---|---|---|
| Hong Kong | Mirs Bay, Tolo Channel, and Tolo Harbour | 1995 - 1995 | rare | 126271 | |
| Portugal | Óbidos Lagoon | 1993 - 1994 | very common | 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 | common | 80786 | |
| England and Wales (UK) | R3 - between North Foreland & Portland Bill | 1973 - 1995 | common | 80786 |