Invasion
Invasion Description
1st Record: North Island/New Zealand/Auckland Harbor (1961, Cranfield et al. 1998)
Geographic Extent
Marsden Point and Whangarei Port, North Island/New Zealand/Whangarei Harbour (Inglis et al. 2006e); North Island/New Zealand/Auckland Harbor (1961, Cranfield et al. 1998); North Island/'Northern NZ harbours' Waikanae River; Tasman Bay, Pelorus Sound (1961, Cranfield et al. 1998); New Zealand/Mahurangi Harbour (1971, Dinamani 1991, cited by Krassoi et al. 2008)
Vectors
| Level | Vector |
|---|---|
| Alternate | Hull Fouling |
| Alternate | Oyster Intentional |
Regional Impacts
| Economic Impact | Fisheries | |
| Magallana gigas is actively fished and cultured in New Zealand (Ruesink et al. 2005). | ||
| Ecological Impact | Competition | |
| 'Following the first observation of M. gigas in Mahurangi Harbour, New Zealand in 1971, the ratio of oyster recruits rapidly changed from 1000 native Saccostrea glomerata to every M. gigas in 1972, to four exotic oyster recruits to every native recruit in 1978' (Dinamani 1991, cited by Krassoi et al. 2008). Magallana gigas has much higher growth rates and fecuundity than the native S. glomerata (Sydney Rock Oyster) (Krassoi et al. 2008). | ||