Invasion
Invasion Description
1st established record: England/Humber estuary (1864, Chew 2001, commercial harvesting by 1889)
1st Record: Bootle/England/Mersey estuary, Irish Sea (1850, Chew 2001, a single shell).
Many local introductions are known, mostly unsuccessful intentional plantings. Some occurrences may have come about with oyster introductions, ballast water, or discarded seafood (Chew 2001).
Geographic Extent
Wales/Menai Straits (1921, Chew 2001, near plantings of American Eastern Oysters, Crassostrea virginica); Bootle/England/Mersey estuary, Irish Sea (1850, Chew 2001, a single shell, failed); Southport, near Liverpool (1883, Chew 2001, failed); England-Wales/Dee Estuary (1883, Chew 2001, failed); England/Humber estuary (1864, Chew 2001, commercial harvesting by 1889); Kent/England/English Channel (1869, Chew 2001, failed); Southampton/England/Southampton Water (1948, Ansell 1963; Utting and Spencer 1992); Portsmouth/England/the Solent (Ansell 1963); Essex/England/Blackwater Estuary (Utting and Spencer 1992); St. Vaaste, Normandy/France/English Channel (1939, failed, Goulletquer et al. 2002); Ireland/Irish Sea (1969, failed, Minchin 2007)
Vectors
| Level | Vector |
|---|---|
| Alternate | Fisheries Intentional |
Regional Impacts
| Economic Impact | Fisheries | |
| Local harvests of M. mercenaria in the Humber estuary started by 1889 (Chew 2001), but we have no reports on the persistence of the population or the fishery. In the Solent, a fishery persisted from the 1950s to the 1980s (Utting and Spencer 1992; Chew 2001). | ||