This year's sea ice formed relatively early – in December and January. Although February was significantly warmer than average, there wasn't enough sunlight to melt the ice. Now, a bit of cold in March may have even increased the sea ice. "There's still quite a noticeable amount of ice," Jüssi told ERR.

Although most seals have already been born by now, the birthing season is not yet over. According to Jüssi, the best winter for seals is one with lots of ice and snow.

"Snow abundance is especially important for ringed seals. They make dens in the snow or drift ice and give birth there like bears. Grey seals prefer drifting ice or to lie on the edge of open water and ice floes. They tend not to go into closed areas where snowdrifts can form," the marine scientist said.

Snowy and icy winters have, according to Jüssi, become quite rare in Estonia. Even this winter was not among the best in terms of the amount of snow and ice. "Looking at the winters of the last 10-15 years, snowy and icy years can be counted on the fingers of one hand. In 2020, there was no sea ice at all. This does not affect the grey seal as much, as it can manage with birthing on land," he observed.

Golden age for the Baltic grey seal

Despite the warm winters in recent years, the grey seal population is doing very well, according to Ivar Jüssi. Last autumn, 6,324 grey seals were registered in Estonia, marking the best result in the last 30 years. For comparison, in 1999, only 1,500 individuals were counted in Estonia. During the low point in the 1980s, it was estimated that there were about 5,000 grey seals across the entire Baltic Sea. According to counts, however, there are currently no more than 1,500 ringed seals in the Estonian sea area.

Jüssi notes that grey seals are much more flexible in their choice of habitats than ringed seals. They can successfully give birth on open sea islands, islets and beaches, whereas ringed seals do not give birth on land.

"Ringed seals have a completely different behavior from grey seals, as they generally do not protect their pups. If there is any danger, they flee, whether it's an eagle, a fox or a random fisherman who comes near their den," the scientist remarked.

"Their adaptation to abandon their pups originated in the Arctic, from where they also came to us. What's the point in fighting a polar bear when it always wins? That's why ringed seals need a lot of snow and ice. When the pups are in dens, predators can't find them as easily," added Jüssi.

Grey seals are much larger than ringed seals and will protect their pups if necessary. According to Jüssi, it's rather rare for predators to kill a grey seal pup. "A ringed seal pup, on the other hand, is very small at birth, maybe a bit bigger than a cat, and easy prey for predators in the open air."

Marine scientist Urmas Lips recently told "Ökoskoop" that the situation for ringed seals is deteriorating year by year, directly related to climate change. "They no longer have ice in the winters where they can give birth and reproduce," he stated.

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