All salmon farmed in New Zealand are King salmon (Oncorhynchus tshawytscha), sometimes knows as Chinook.
King salmon is the only salmon species farmed in New Zealand, whereas the main species of salmon that is farmed globally is Atlantic salmon (Salmo salar).
King salmon are anadromous fish, meaning they are adapted to life in both fresh and sea water. They are born in fresh water land-based hatcheries before being transferred to sea pens or fresh water farms for up to 18 months until they reach harvest weight of approximately 3-6kg.
Most sea farming occurs in the Marlborough Sounds, Stewart Island and Akaroa Harbour, while fresh water operations in Canterbury, Otago and Tasman utilise ponds, raceways and hydro canals for grow out operations.
The sea pens used are made of netting and are around 18,000 cubic metres in size. New Zealand’s low stocking densities, ranging between less than 1 kg/m3 up to around 25 kg/m3 (depending on the life stage of the salmon).
In New Zealand, our focussed farming practices, strict bio-security procedures and absence of any native salmon species mean that our King salmon are raised without need for vaccines or antibiotics.
New Zealand farmed salmon are fed food pellets specially formulated for King salmon and contain no steroids or other growth enhancers.
The New Zealand Salmon Farmers Association’s Finfish Aquaculture Environmental Code of Practice states that raw material for fish feeds should come from sustainably managed fisheries.
Farm site selection is so critical that only a handful of sites around the country are considered suitable for salmon operations.
Farms tend to be placed in areas with strong currents to flush the pens and improve the rearing environment and minimise the effects of waste on the environment.
Ongoing monitoring of farms is required to be carried out by marine farmers and regional councils.
New Zealand’s salmon farming industry has been recognised as the world’s greenest by the Global Aquaculture Performance Index.