There are 32 farms authorised to grow salmon in New Zealand, covering a total of around 152 ha (as of March 2009). New Zealand’s farmed salmon accounts for over half of worldwide farmed king salmon (Oncorhynchus tshawytschca) production. In 2008 king salmon had an export value of $44 million – a 22 per cent increase over 2007.
The main king salmon farming areas are in South Island waters. King salmon are grown in sea cages in the marine environment and in freshwater raceways. Sea cages are located in the Marlborough Sounds, Akaroa Harbour and Stewart Island. Freshwater raceways are mainly located in several Canterbury rivers including the Rakaia and Waimakariri rivers.
The farming method for king salmon in the sea uses large floating cages moored to the sea floor. Each cage contains several thousand salmon, which are grown from smolt to a weight of around 3.5 to 4 kg each.
The farming method for king salmon in freshwater uses cages placed in rivers. In the Mackenzie Basin salmon farms have been established in hydroelectric canals. Smolt from hatcheries are placed in the cages and raised to a weight of between 2 to 4 kg each.
At www.aquaculture.govt.nz you can learn more about ecological effects, food safety, production systems, and planning and legislation for king salmon.
Review of the Ecological Effects of Marine Finfish Aquaculture: Final Report by Cawthron for the Ministry of Fisheries, 2007 (PDF, 3.56MB)