Biodiversity: Trout restocked in the Tornio River

Finnish steelmaker Outokumpu commissioned the stocking of about 3,300 sea trout and 24,000 migratory common whitefish in the Tornio River delta in 2007. The fish population is to be restocked every year.

The restocking was carried out as a part of the Outokumpu Tornio facilities' statutory payments to the fishing industry. The payments are used to finance research and projects selected by the authorities. The Tornio facilities have agreed with the fishing authorities that their payments be used specifically for reviving the depleted local stocks of valuable fish in Tornio River, namely its indigenous stocks of local sea trout and migratory common whitefish. This will mostly benefit the endangered marine life and the inhabitants of the area.

The value of the planted fish was about €10,000. The fish were planted by the Finnish Game and Fisheries Research Institute under the supervision of Lapland’s fishing authorities which, at the same time, made sure that the fish were healthy and of high quality.

Outokumpu’s environmental obligations also include the regular surveying of the fish stocks and the bottom fauna found adjacent to the facilities. The main results of these surveys indicate that even the fish found in the waters in front of the facility are healthy, reproductive and edible. The amounts of metals found in the fish have practically not increased.

The results of the surveys of fauna are more difficult to interpret due to the species’ natural variation. Furthermore, the opening of a shipping lane, the dredging of the harbour and the heaping of dredged earth in the area also affect the results. Some fauna, such as mussels and gastropods, found near the facility’s sewer are showing higher contents of metals, because these species filter their nutrients from mud and bottom sediments which have, over time, accumulated metal deposits. The surveys, however, have indicated that the facility’s sewage water were not toxic, and the changes in the fauna population cannot, according to existing data, be directly linked to the facility or its sewage water.

Restocking fish populations

• What is it about: Outokumpu commissioned the planting of trout in the Tornio River
• Background: the Tornio facility’s statutory payments to the fishing industry were used to revive
  fish stocks
• When it took place: spring 2007
• Fish species: 3,300 sea trout and 24,000 common whitefish
• Future: more restocking will be carried out in coming years.