Salmon farming

1988/10/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Arrantza

Now things have changed. Salmon has become one of the most common in restaurant charts and fish shelves. This has been possible thanks to the industrial growth of salmon.

Salmon farming has become a very productive and widespread industry in several North European countries. Salmon grow in boxes in suitable coastal areas. These places must be as protected as possible from the sea currents and the fury of the sea. That is why bays, bocanas and rías are chosen to grow salmon. But the growing demand for salmon and the end of the coastal protected areas are raising offshore growth in Scotland.

The growth will take place in specially built arches. These boxes must be able to withstand 6 m high waves. At the top of the boxes there will be a food deposit and a computer will control when the food is released. This system will prevent fish from starving in adverse weather conditions and where carers cannot go to boxes. The boxes will be located one kilometer from the coast. Each box can contain 40,000 salmon units and a productivity of 105 tons per year is expected.

Open sea cultivation has certain advantages. Water circulates better through boxes and cleaner water. On the other hand, the salinity of the water is not altered by the tide in the usual places. Fish waste and food surpluses are also easier to clean and cause no problems. In protected areas, the accumulation of organic matter produces a rapid proliferation of bacteria that can consume oxygen from the water.

The biggest disadvantages of open sea farming are the damage that the loose sea can cause in boxes and fish.