| Country | Locality | Introduced | Year | Qualitative Value | Ref. |
|---|---|---|---|---|---|
| Sweden | Persö, Askö Archipelago, Baltic Proper | 2003 - 2003 | common | 95728 | |
| Germany | Pomeranian Bight with Adlerground | 2002 - 2012 | very common | 96045 | |
| Sweden | Site A, Forsmark Nuclear Power Plant, Bothnian Sea | 1984 - 1984 | rare | 95961 | |
| Sweden | Site A, Forsmark Nuclear Power Plant, Bothnian Sea | 1984 - 1984 | rare | 95961 | |
| Sweden | Site A, Forsmark Nuclear Power Plant, Bothnian Sea | 1985 - 1985 | rare | 95961 | |
| Sweden | Site G, Forsmark Nuclear Power Plant, Bothnian Sea | 1984 - 1984 | rare | 95961 |