Man-made snow banks proved useful nesting sites for endangered Saimaa ringed seal
Seal pups explore wider areas than previously thought
Man-made snow banks have proved to be useful nesting sites for the Saimaa ringed seal (Pusa hispida saimensis)
This year the first seal pups were born in the “artificial nests”, built by seal researchers on the banks of the Haukivesi and Pihlajavesi lakes, belonging to the Saimaa water system.
The man-made snow bank experiment has lasted for the past two, exceptionally snowy winters. “People did tend to laugh at us when we were ploughing the snow for the seals”, researcher Miina Auttila admits.
The fact that the seals preferred the man-made banks, even though they had plenty of snowy locations to choose from, proves that the experiment was useful. The man-made nesting opportunities will definitely be beneficial in less snowy winters, Auttila says.
One of the important questions in Saimaa ringed seal protection is how much predators reduce the population.
According to the researchers the attrition rate from predators seems to have remained low.
The research results by the University of Eastern Finland are used when deciding on protection measures for the Saimaa ringed seal.
Such measures include for example net fishing bans in the spring and early summer. The idea of the bans is to prevent seal pups from getting caught in the nets and drowning.
According to researcher Marja Niemi, who has followed the seals’ movements with radio signals, it appears the seal pups explore much larger areas than was previously thought. They can travel up to 15 kilometres in a 24-hour period. One pup journeyed no less than 25 kilometres away from the nest.
Based on the monitoring, researchers conclude that last year’s protection area covered 95 per cent of the pups’ habitat.
In the spring, the ban was widened and all the monitored pups stayed inside the protection area.
The unfinished research project is also aiming to look into the genetics of the Saimaa ringed seal.
According to researcher Mervi Kunnasranta, the seal reproduces well, but its genetic makeup may give an answer to the question why so many of the pups die in infancy, before they even leave the nest.
The Saimaa ringed seal is descended from ringed seals that were separated from the rest by post-glacial land uplift, and is found uniquely in the Saimaa basin.
The animal, one of few freshwater seals found anywhere in the world, is extremely endangered, with a population smaller than 300.
It has been protected since the 1950s. Numbers have risen from a low of just 100-150 individuals in the early 1980s, but the seal remains on the critical list, not least because of warmer winters (with the obvious exception of the last two) that have hampered the making of nesting sites.
Previously in HS International Edition:
Protection of Saimaa ringed seal puts shoreline construction under closer scrutiny (1.4.2011)
Modest recovery in Saimaa ringed seal population (11.11.2010)
Researchers pile snow for use as nests by endangered Saimaa ringed seals (8.1.2010)
Saimaa ringed seal extinction likely without massive conservation measures (17.2.2009)
European Commission prepared to bring Finland to court over protection of Saimaa seals (6.5.2010)
Scattered restrictions on net fishing harm Saimaa ringed seal population (12.8.2008)
Saimaa ringed seal (Wikipedia)