Image: Ismo Pekkarinen / AOP

In late December, the Lake Saimaa habitat of the Saimaa seal was bare ice with patches of still open waters.

To survive the rigours of the winter, and to protect them from predators, seal pups born in late February or early March need the protection of a den dug deep into a snow bank close to the lake shore. Researchers say that without sufficient snow cover, as many as half of the pups could die.

"A snow front moved across the Saimaa region on Saturday with winds topping ten metres a second. This created some snow drifts. There aren't quite enough yet, even though nesting conditions are a lot better," conservation biologist Jouni Koskela told Yle. "A few more windy flurries are needed, and that's what's in this week's forecast."

The state natural resources sector service provider Metsähallitus will review the situation and make a decision on the 18th of this month about whether or not there is a need to pile up more snow to create artificial sites where seals can dig dens. Environmental authorities will keep the window open for such a move until mid-February.

"If there's not enough snow, volunteers will be brought in, meaning that a couple of hundred people with snow shovels will rush to help," Koskela explains.

The biggest risk right now is that a warm, rainy spell of a week could melt the snow that has already accumulated. A shorter period of warming, followed by freezing temperatures, would benefit the seals by creating a hard shell over the snow drifts.

Population on the rise

Based on last spring's count, the entire population of these rare freshwater seals is estimated at 360 individuals. There were 80 pups born last winter, briefly raising the population over the 400 mark.

"Calculating for natural deaths, infant mortality, and those that get tangled and die in fishing nets, there are probably now 370 to 380 individuals," says Jouni Koskela.

The target set for the Saimaa seal population by conservation programmes is 400 of these elusive creatures to be living in the eastern wilds by 2020.