Government seeks to dismantle Palokki plant despite power concerns

The Finnish state wants to buy and dismantle the Palokki hydropower plant in Heinävesi, restoring the rapids below the dam for endangered salmonid fish, Yle reports. The municipalities that own the electricity company must decide their position on the offer during the autumn.

Prime Minister Petteri Orpo’s government made an offer to buy the plant from Pohjois-Karjalan Sähkö during the summer. The government wants to remove the plant and its dam in cooperation with regional stakeholders, potentially restoring habitats for endangered fish.

Orpo has said he personally included the promotion of restoration work on the Palokki rapids in the government programme. The plant currently regulates water flow through nine rapids below the dam.

Trout more likely to benefit than salmon

Matti Janhunen, a senior researcher at the Natural Resources Institute Finland, said lake trout would be more likely than landlocked salmon to benefit from the restoration. Both species currently depend on stocking.

The landlocked salmon population has been very weak since the 1970s and requires continuous renewal of broodstock and the production of juveniles at fish farms, Janhunen said. Without human assistance, the population would disappear from the wild quickly, he estimated.

The return of landlocked salmon to a natural life cycle is threatened by the limited availability of suitable habitats and by the species’ narrow genetic diversity. Researchers are seeking solutions through crossbreeding.

The situation is somewhat better for lake trout. Local trout populations occur in some of the smaller streams in the Vuoksi water system, and the free-flowing rapids on the Heinävesi route are its most important natural reproduction area.

Janhunen said nobody knows for certain how restoration would affect juvenile fish production at Palokki. He considered it more likely that trout could be re-established on the Juojärvi route and at Palokki than that landlocked salmon could succeed there.

Trout could use smaller tributaries for juvenile production and Juojärvi as a migration area, Janhunen said. Because trout have a smaller range than landlocked salmon, protecting them from fishing would also be easier.

Janhunen said the success of landlocked salmon at the Palokki rapids was uncertain because reproduction alone would not end the species’ dependence on human intervention. The available area for juvenile production and the survival of fish through the different stages of their natural life cycle would determine whether a sustainable, self-reproducing population could develop.

He also warned that climate change could increase dry periods, making low and warm water potentially fatal for salmonid juveniles. He said efforts to restore landlocked salmon would have to continue for decades before their success could be assessed, and questioned whether the population would ever become strong enough to withstand fishing.

Plant important to electricity security

Anssi Paalanen, a leading preparedness specialist at the National Emergency Supply Agency, said the Palokki plant is important to the electricity system. Without hydropower, electricity use would have to be restricted.