Location of oyster- and mussel-growing areas of the North (NI) and South Islands (SI) of New Zealand. A, Whangaroa Harbor; B, Bay of Islands; C, Kaipara Harbor; D, Mahurangi Harbor; E, Coromandel; F, Hauraki Gulf; G and H, Marlborough Sounds. Superscript letters: P, Pacific oysters; G, Greenshell mussels; D, dredge oysters.