Invasion

Invasion Description

1st Records: North Island/New Zealand/TeTii Bay (1994-2010, Westfall and Gardner 2010, Gardner and Westfall 2012, 35° 08.768' S 174° 00.258' E); Waitangi/North Island/New Zealand/TeTii Bay (1994-2010, Westfall and Gardner 2010, 35° 16.718' S 174° 05.383' E); North Island/New Zealand/Oakura Bay (1994-2010, Westfall and Gardner 2010, 35° 22.975' S 174° 20.890' E); North Island/New Zealand/Wellington Harbour (1994-2010, Westfall and Gardner 2010, 41° 17.000' S 174° 50.000'E); Mussel Point, South Island/New Zealand/Pacific Ocean (1994-2010, Westfall and Gardner 2010, 41° 43.989' S 174° 16.052' E, northern genotype)

Molecular analyses indicate that most populations were derived from Pleistocene migrations of M. galloprovincialis and/or M. edulis and represent one or more undescribed species (Daguin and Borsa 2000; Hilbish et al. 2000). However, purebred mussels of the Northern Hemisphere genotype, and hybrids between the northern M. galloprovincialis genotype and M. edulis were found at several sites on the North Island and at Mussel Point (41° 43.989' S 174° 16.052' E), near Cape Campbell on the South Island (Westfall and Gardner 2010). In New Zealand, high rates of introduction and hybridization may result in replacement of the southern genotypes by the introduced northern genotypes (Westfall and Gardner 2013).

Geographic Extent

North Island/New Zealand/TeTii Bay (1994-2010, Westfall and Gardner 2010, 35° 08.768' S 174° 00.258' E); Waitangi/North Island/New Zealand/TeTii Bay (1994-2010, Westfall and Gardner 2010, 35° 16.718' S 174° 05.383' E); North Island/New Zealand/Oakura Bay (1994-2010, Westfall and Gardner 2010, 35° 22.975' S 174° 20.890' E); Wellington, North Island/New Zealand/Cook Strait (Daguin and Borsa 2000; Hilbish et al. 2000, southern gentoype); Mussel Point, South Island/New Zealand/Pacific Ocean (1994-2010, Westfall and Gardner 2010, 41° 43.989' S 174° 16.052' E, northern genotype)

Possible Hybrids: Wharariki Beach, , off North Island/New Zealand/Hauraki Gulf (2000-2008, Gardner et al. 2016); Waiheke Island, off North Island/New Zealand/Hauraki Gulf (2000-2008, Gardner et al. 2016); Mussel Point, South Island/New Zealand/Cook Strait (2000-2008, Gardner et al. 2016) Maud Island/New Zealand/Cook Strait (2000-2008, Gardner et al. 2016); Wellington Harbour /New Zealand/Cook Strait (2000-2008, Gardner et al. 2016); 'Ocean Patriot' oil rig, off New Zealand/Tasman Sea (purebred northern hemisphere M. galloprovincialis (2000-2008, Gardner et al. 2016) (WHOB), which may indicate that these populations contain hybrids between native Southern and invasive Northern Hemisphere blue mussels.