Fish farming in the sea takes place in net cages where the fish are typically kept for two growing seasons. The juveniles are brought to the sea in the spring or autumn, when they are about a span in length, i.e. the distance from the thumb to the little finger. At the end of the first growing season, rainbow trout weigh a few hundred grams. After the second growing period, rainbow trout typically weighing a little over two kilograms are gutted and processed for retail. The sale weight of whitefish is about one kilogram.

The production of farmed fish moves to the open sea

The production of farmed fish has declined since the peak years of the 1990s due to the reduction or withdrawal of environmental permits in sensitive marine areas. However, nutrient emissions from fish farming have fallen by 60-70%, compared to the highest nutrient loads of the past.

Towards the end of the 2010s, production began to grow slowly as new environmental permits were granted, allowing farms to be located in new offshore areas. Fish farming production is expected to continue to grow in areas where farming conditions are suitable but the activity does not create any adverse environmental impact. 

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The Blue Bioeconomy

The breeding of juveniles, as well as winter storage of fish, may continue close to the coast since the nutrient load of these activities is low.

The cages of the final growing season are located in the shelter of the outermost islands or may even be completely offshore. The regional positioning of fish farming is guided by, inter alia, a national aquaculture management plan prepared by the Ministry of Agriculture and Forestry and the Ministry of the Environment.

Using Baltic Sea feed reduces the nutrient load to the Baltic Sea

Farmed fish are fed with feed pellets. Feed materials increasingly use vegetable-based raw materials. Most of the fish used for producing feed comes from herring and sprat, which have been caught from the Baltic Sea. Environmental toxins, such as dioxin, have been removed in the manufacture of fishmeal and fish oil.

This type of feed has come to be named “Baltic Sea feed”. It recycles the phosphorus and nitrogen from the fish stocks in the Baltic Sea to the farmed fish. This will reduce the flow of nutrients from outside the Baltic Sea.

Due to the reduced environmental impact of fish farming, the Finnish World Wildlife Fund (WWF) has classified domestic fish as being on the “green list”. This means it is environmentally sustainable. Another advantage of farming domestic rainbow trout is that there are no salmon lice in Finnish marine areas, which are a major threat to Norwegian salmon farming. Nevertheless, over 70% of the salmonid fish consumed in Finland is imported from abroad. 

Point of view

Domestic fish produced in a sustainable way

Aquaculture is a growing industry worldwide

Fish is an important part of a healthy diet, not least because of the good omega-3 fatty acids it contains. It is recommended that a variety of wild fish and farmed fish should be eaten at least twice a week.

Natural fish stocks alone cannot meet the increasing demand for fish. Fish, crustaceans, and molluscs are the fastest-growing food production sector in the world. More than half of the fish destined for human consumption comes from farming. By contrast, the proportion of fishing is decreasing year by year.

Fish are highly efficient at getting the most from their feed. As a result, compared to other forms of animal production, the carbon footprint of fish farming is small.

Fish farming is also of great economic importance to many Finnish archipelago communities. It provides year-round jobs and provides tax revenue to maintain services. All in all, if well-planned, fish farming does not conflict with other livelihoods and environmental goals.