Cage Culture

Cage Culture

Cages and net pens are used for Atlantic, Coho, Chinook salmon, and Rainbow Trout. They have been used for several years in Maine, New Brunswick, British Columbia, Washington, Chile, and Australia.

The site selection is very important. If possible, they should be sheltered from wind and waves. The tidal conditions must be correct: flow of about 0.6 meters/second, and a minimum depth of 10-20 meters at low water and low tide.

Nets are cubical or cylindrical in shape. They are suspended from flotation devices and extended above the surface to keep fish from jumping out. A layer of netting is placed over top to protect salmon from hungry birds.

Cages are usually 10 meters by 7 meters, with a volume of 700 cubic meters. This yields about 18 tonnes of fish.

Circular cages are made of polyethylene pipes filled with polyethylene foam. They are up to 25 meters in diameter with a volume of 1500 cubic meters. This results in about 40 tonnes of salmon.

There are two systems of cage management. In Scotland, cages are small and management is intensive. In Norway, cages are large and management is less intensive.