New Zealand Green Mussels

New Zealand green mussels are farmed exclusively in New Zealand and have been exported to the United States since 1979. Other major importers are Japan, Australia, and Europe. In 2016, production harvest was 94,037 tons. The 2002 harvest of 78,000 tons was worth USD $85.8 million. In 2000, there were 605 farms in New Zealand.

Green mussels are cultivated on ropes, rafts, and longlines and are harvested using specially designed harvesting vessels. Farming methods are mechanized and are highly cost-effective. The New Zealand government tightly regulates growing standards like water quality and production levels. Because of this, product quality is considered consistently high.

Seed, or spat, for the mussels comes from wild sources. Farmers have a spat settlement monitoring program, where they will suspend spat catching lines in areas where there are high numbers of planktonic mussel larvae ready to settle. This method is expensive and only represents a small portion of total spat collected, but the mussels are high quality. Farmers will also take advantage of a natural phenomenon occurring on the North West Coast of the North Island. At irregular times throughout the year, the area provides considerable quantities of newly settled spat attached to washed up pieces of seaweed, creating a major source of spat. The seaweed is collected by locals and distributed to growers throughout the country.

Overall, mussel farming in New Zealand has minimal ecological impact near or on established farm sites because most farms are sited in areas away from cities and where green mussels occur naturally. The presence of mussels may actually benefit many other marine life and also provides a flow-on benefit for recreational anglers. No harmful chemicals or additives are used during the farming process.