The Saimaa ringed seal population continues to grow despite increasingly mild winters with little snow. According to a recent population assessment, there are now 530 Saimaa ringed seals in Finland's Lake Saimaa system.
This represents an increase from last year's estimate of 495 individuals. The population is growing rapidly in Puruvesi and southern Suur-Saimaa areas, but concerns remain about northern Saimaa.
The population estimate reflects January numbers and doesn't include pups born later in spring. Experts base these figures on nest counts supplemented by various monitoring data.
This year, 114 seal pups were born, up from about 80 annually a decade ago. However, poor nesting conditions have led to high pup mortality rates. This year's mortality reached 19 percent, while last year it was 21 percent. Under good conditions, mortality typically stays around 10 percent.
"Last winter was very mild with little snow," said conservation specialist Riikka Alakoski in a statement. "That's why most artificial nests were in use, and 85 percent of observed newborn pups used them for protection. Without these nests, pup mortality would have been even higher."
Fishing equipment also causes additional mortality among young seals, Alakoski noted.
So far this year, 45 dead Saimaa ringed seals have been found. Among these, 21 were pups that died before weaning, eight died in fishing gear, and the rest died from other causes. Some causes of death are being investigated through autopsies.
Fishing restrictions have proven effective in protecting the endangered seals. Expanding restricted areas since the 2010s has allowed more seals to reach reproductive age, reflected in growing pup numbers.
"Fishing gear mortality remains a significant cause of excess deaths that slows population recovery," said conservation specialist Miina Auttila. "Most seals die in nets, with mortality concentrated after the net fishing ban ends from July to September. However, nets remain dangerous year-round."
The Pihlavesi area population shows stable growth, producing 40 percent of all pups. Some individuals have likely moved from Pihlavesi to Puruvesi. Both Puruvesi and Suur-Saimaa show rapid population growth with record numbers of pups observed.
The first Saimaa ringed seal pups appeared in Puruvesi and Suur-Saimaa only in the 2000s, returning to areas where human activity had previously eliminated them.
Nesting density maps show nesting areas have expanded particularly in Puruvesi and Suur-Saimaa. Movement in denser population areas during nesting season increases disturbance risks.
"The situation is concerning in northern Saimaa, especially the Pyhäselkä-Jänisselkä area where no pups have been born for three years," Auttila reported. "Only one pup annually has been observed in nearby Orivesi. Still, seals are spotted in the area yearly, all the way to the Joensuu region."
Over 300 local volunteers participate annually in monitoring and protection efforts, including nest counts and maintaining artificial snow nests.
The government is currently updating regulations on fishing restrictions in Saimaa, with public consultation open for input. The North Savo Centre for Economic Development will host four public meetings in November.
The continued population growth shows conservation efforts are working, but the species remains vulnerable to climate change and human activity. The disparity between thriving southern populations and struggling northern ones highlights how localized conditions affect recovery efforts.