The most important fish stocking of the year take place at the mouth of the river Iijoki

The fish population of the Iijoki waterway and the sea area is maintained by stocking. Pohjolan Voima is responsible for the obligatory fish stocking in the river Iijoki waterway and sea area as well as in the two adjacent lake districts.

In the spring a total of 310,000 salmon and 29,000 of trout fry are stocked in the area under the obligation. The released fry are bred at Raasakka fish farm by Voimalohi Oy. In addition, over 10 million newly hatched whitefish fry are stocked in the river mouth. They are bred at Rantakestilä fish hatchery by the Southern and Northern Ii fishery associations both as part of the obligatory stocking and as voluntary stockings initiated by the fishery associations. The Rantakestilä fish hatchery also produces 3-5 million lamprey larvae. The number of fry stocked is based on the natural reproduction of the fish.

The upper basin of Raasakka power plant is stocked with rainbow trout in the summer and pike perch in the autumn. A total of 1.2 million one-year old pike perch fry are stocked in the mouth of the river Iijoki every summer, and 60,000 lampreys are transferred above Raasakka hydropower plant.

The fish stock is improved through co-operation

Together, the officials, Pohjolan Voima and the local fishery associations have agreed on changes to the original stocking obligations. The common aim has been to improve the Iijoki waterway and sea area fish stock. According to the proposal staged by the Southern and Northern Ii fishery associations, 40,000 salmon will be changed into trout by the year 2010. In addition, 10 per cent of the stocking of one-year-old pike perch fry has been changed to newly hatched fry. To improve the sea trout catch, the local fishery associations further culture 7,000 fry in fattening cages so that they can be released as bigger fish. The success of the stocking is constantly monitored.

Further information:
PVO-Vesivoima Oy, Mr Aaro Horsma, Manager, Environmental Affairs