Salmon and trout populations in Oulujoki maintained through Oulun Energia’s annual plantings

01.09.2022

Oulun Energia annually plants salmon, sea trout, and whitefish in Oulujoki as part of Merikoski’s fish planting obligation. The plantings have gone excellently this year—the fish have been successfully restocked and it was an exceptionally good year for whitefish last year.

Oulun Energia’s planting obligation is composed of nearly five thousand sea trout, over 25,000 young salmon and of millions of newly hatched whitefish. The purpose of the plantings is to compensate for the damage to the fish economy caused by construction, to maintain the salmon and trout populations, and to enable fishing.

The salmon and the trout are planted in May in the delta of Oulujoki, where the fish are transported with a fish transport truck, from which they are lowered into the river through a long pipe.

The journey of the migratory whitefish destined to be planted starts in the fall from milked whitefish eggs, after which they are taken to the Montta fish farm to spend the winter in the hatchery. The whitefish larvae hatch in early May, after which some of them are planted in the lower part of Oulujoki, below the Merikoski power plant. Meanwhile, some of the fry are sent to natural food ponds for further development, where the fish can grow on natural food until autumn. The autumn fry are planted into Oulujoki in September or October.