Finding a commercial use for mussel and oyster shells would also be of major benefit to New
Zealand’s shellfish industry. Currently, most shell material is dumped as waste or given away
to farmers. For example, Sealord Shellfish Ltd in Nelson pay $40/tonne for removal of mussel
shell waste material (pers. comm Graham Fox, Sealord) and Sanford Ltd in Marlborough leave
their mussel shell waste in open pits in forests for one year before giving it away to vineyards
and farmers (pers. comm Mike Mandeno, Sanford). A major source of mussel shell in the
North Island is from North Island Mussel Processors Ltd (NIMPL) in Tauranga, which is coowned
by Sanford Ltd, Sealord Shellfish Ltd and Greenshell New Zealand Ltd. Mussel shell is
also available within the Auckland region, for example WestPac Ltd in Henderson produce 1-3
m
3
d-1 of crushed mussel shell. Other companies such as Sea Products Ltd in Drury also
process mussels, and Kia Ora Seafoods Ltd in Manukau produce 4 m3
d-1 of oyster shell waste
throughout the winter.