Officials seek fish passages to restore Lake Pielinen salmon in Lieksanjoki

Authorities want to restore naturally migrating fish populations in the dammed Lieksanjoki river, Yle reports. The fisheries unit of the Eastern Finland Centre for Vitality has submitted an application to the Permit and Supervisory Agency seeking changes to the fisheries obligations of the Lieksankoski and Pankakoski power plants.

The application concerns the critical status of Lake Pielinen’s landlocked salmon, which is close to extinction, according to Markus Huolila, a fisheries biologist at the centre.

When the power plants were built more than 50 years ago, it was believed that fish stocks could be preserved by raising them in hatcheries. That approach has now reached its limits, Huolila said.

Based on current knowledge, migratory fish populations cannot remain healthy and genetically diverse in hatcheries.

The plan would return water at the Lieksanjoki power plant to its natural channel, where a spawning area for migratory fish could be restored. The natural channel is currently almost dry.

At Pankakoski, the power plant dam forms a complete barrier to fish migration. The application’s central demand is that the plant owner, Kemijoki Oy, be required to build fish passages for both upstream and downstream migration.

“It is possible to create naturally reproducing and self-sustaining populations of Lake Pielinen salmon and trout in the Lieksanjoki region,” Huolila said.

Lieksanjoki was once a home river for salmon

Before the power plants were built, the Lieksanjoki was the only spawning and juvenile production area for Lake Pielinen’s landlocked salmon and the most important such area for trout. Large plankton-feeding whitefish also migrated from Lake Pielinen into the river to spawn, and the grayling population was strong.

The Lieksankoski power plant was completed in 1960 and the Pankakoski plant in 1964. Their construction destroyed the spawning and juvenile production areas for river-spawning fish between Lake Pankajärvi and Lake Pielinen.

Fish populations have since been maintained through stocking. Landlocked salmon caught downstream of the Lieksankoski power plant and moved to rapids upstream of Lake Pankajärvi have spawned and produced juveniles.