Climate change is one of the most significant threats to the Saimaa ringed seal. The LIFE Saimaa Seal Project developed methods for combating the threats caused by climate change.

The mother seal gives birth to a pup in a lakeshore snowdrift in February-March. Due to climate change, the mild winters cause a significant threat to the reproduction of the Saimaa ringed seal, if there is not enough snow. Without the protection of the lair, the pup is exposed to cold, predators and other disturbances.

The University of Eastern Finland has carried out research, in order to combat the threats caused by climate change. In prior studies, it has been detected that Saimaa ringed seals have accepted man-made snowdrifts as their lairs. The aim of the LIFE Saimaa Seal was to further develop the method of man-made snowdrifts. For the mild winters to come, a system covering the entire Lake Saimaa region is to be created. This way, the breeding can also be safeguarded in the future.

Man-made snowdrifts support breeding

The system of man-made snowdrifts has been tested in practice in the years 2014–2018. The annual amount of the man-made snowdrifts has varied in years 2014–2017 from 68 to 281, depending on the snow conditions in different parts of the breeding area of the seal. More than 250 volunteers and dozens of hired workers from different organisations have taken part to the work.

The man-made snowdrifts were a success: when carrying out the annual counting of the lairs, it has been stated that 80 % of the man-made snowdrifts had been used as lairs by Saimaa ringed seals. Out of the pups born in these four winters, almost 70 % were born in man-made snowdrifts. In the years 2014 and 2017, when there was not enough natural snow, and drifts were made all around the Lake Saimaa area, more than 90 % of the pups observed were born in man-made snowdrifts.

The development of this method continues, and such tools as a snow cannon were tested for producing snowdrifts. While more durable snowdrifts could be achieved using a snow cannon, this method requires heavy and unwieldy equipment. The large extent and fragmented nature of the Saimaa ringed seal’s breeding range, as well as the need to operate fast to minimise disturbance, makes it impossible to use snow cannons for this purpose.

In addition to man-made snowdrifts, two types of man-made lairs have been developed: a floating lair built with peat slabs and an artificial lair made from reeds. The development efforts have met with success: a seal’s breathing holes were found near a peat lair, and in winter 2017, a pup was born in a combination of a reed lair and a man-made snowdrift! This work continued in winter 2017–2018.

The project report recommends that the man-made snowdrift method be used on a permanent basis in the protection of the Saimaa ringed seal. Thanks to the man-made drifts, deaths of young pups were reduced clearly from previous winters with light snowfalls.

• New methods improve conservation and monitoring of the Saimaa ringed seal in a changing climate (julkaisut.metsa.fi, in Finnish with English summary)

More Information

• University of Eastern Finland / Saimaa Seal Research: Researcher Marja Niemi, marja.niemi(at)uef.fi
• Metsähallitus: Conservation Biologist Miina Auttila, miina.auttila(at)metsa.fi