| Main Ref. | Vierna, J., K.T. Jensen, A.M. González-Tizón and A. Martínez-Lage, 2012 |
| To | Limfjorden and Danish Wadden Sea |
| FAO area | Atlantic, Northeast |
| From | North America |
| FAO area | |
| Year | 1979 |
| Range | |
| Period | 1975-present |
| Established in the Wild | |
| Established in Aquaculture | |
| Significant Ecological Interactions | |
| Significant Socio-economic Effects | |
| Introduced by | |
| Reason | ballast water |
| Other Reason | |
| Comments | Shells of Ensis directus found in Blåvandshuk suggest they were born in 1979 (Ref. 114889). Samples of E. directus were collected from several sites: Sillerslev, Sundsøre, Juvre Deep, and Vester Vedsted in 2005-2008 (Ref. 114890). |