Saimaa ringed seal

Virtual Finland
May 2004
by Marja-Liisa Karjalainen, journalist at Savonlinna
Photos: Timo Seppäläinen

The Saimaa ringed seal (Phoca hispida saimensis) is a subspecies of the ringed seal and exists only in the Saimaa lake system of eastern Finland. It is an endangered mammal, under WWF protection, with only 270 individuals remaining in the wild. But resolute conservation work over the past few years is beginning to pay off at last and the seal population has actually grown slightly.

Photo: Timo Seppäläinen

The Saimaa ringed seal is an endangered species, unique to Lake Saimaa in Finland. The female seal gives birth to a single pup in February. The pups are counted every year so that the population can be monitored. The mother seal lies on the ice while her pup practices diving in the open water nearby.

Threat

It has been estimated that the immediate threat of extinction would be alleviated if the population of Saimaa seals could be brought up to 400 individuals. At present, Saimaa ringed seals are found in special national parks that have been set up at Linnansaari and Kolovesi in Lake Saimaa. The seals also breed in other Natura 2000 nature conservation areas of the Saimaa water system, such as lake Pihlajavesi.

Raising the young

Seal lairs are located under thick snowdrifts on the ice near the shoreline rocks of the lakes. The female seal hollows out a shelter for herself in the snow. In the floor of the shelter she makes a hole in the ice through which she can slip into the lake water below. The seal pups are born at the end of February or in early March. The newborn seals are covered in grey fur, known also as lanugo, and spend the first few weeks of their lives secure in their lairs, feeding on the nutritious fatty milk of their mothers.

A typical seal lair on a small rock, after the seal and its pup have left. If the weather turns mild or it begins to rain, the roof of the lair can easily collapse. If that happens, the seal has to make a new lair, usually near the first one.

When they have grown a little, the time has come to learn to swim and dive and explore the nearby waters. “The seal pup spends the first few months of its life with its mother, from February until the summer. Then the mother weans the pup,” explains conservation biologist Jouni Koskela at Metsähallitus, the Finnish Forest and Park Service. On sunny spring days, the seal pup and its mother enjoy basking in the sun on the ice. If the weather is windy, they stay in their lair, sheltered by the snow.

Good breeding conditions

The count of lairs with seal pups in them has just been completed this year, and as many as 64 pups were found. The number of pups is a record in the history of censuses carried out since 1981. The breeding conditions this spring were excellent for the Saimaa ringed seal. “The Saimaa ringed seal digs its lair deep in a snowdrift, so in order for the seals to breed successfully, sufficient snow is essential. This year, we had a lot of snow,” says Koskela.

Matti Heikkinen collects from the lair a sample of the baby fur shed by a seal pup. Newborn seal pups have grey fur, but they soon shed it and grow a new darker coat. The number of seal pups is deduced on the basis of lairs because seals and their pups are very difficult to spot in the wild. There is always only one seal pup to a lair. The moulted grey fur is the surest sign that a pup was born in this particular lair.

For the durability of the lair the air temperature is also crucial; it should stay cold enough while the seals are in their lair so that the snow does not melt and cause the roof to collapse. “There was a mild period in March when the roofs of some lairs did collapse. But by then I doubt if it was very serious for the pups,” Koskela says.

Water level fluctuation

Another important factor is the water level of the lake. As already mentioned, the Saimaa ringed seal makes its lair on the ice quite close to the shore and makes a hole in the ice in the floor of the lair so that it can slide into the water. Fluctuations in the water level of Lake Saimaa create problems for a mother seal feeding her pup in the lair. If the water level drops too much, the result could be a crack in the ice that would destroy the lair. Or, if the water rises too much, the lair will flood. “This winter, the water level has stayed pretty stable,” Koskela says.

Up to the 1980s regulatory adjustments lowered the water level in Lake Saimaa during several winters. Today, the breeding habits of the ringed seal are taken into account when water level adjustments are being planned.

Volunteers count lairs

Fifty to sixty seal pups are born on Lake Saimaa every year. Many people who live along the shore or have holiday cabins there volunteer each spring to help the national Forest and Park Service, searching many parts of the lake counting lairs where seal pups have been born. This produces valuable information on the breeding success, population trends and life of the Saimaa ringed seal in general.

One of the volunteers is Matti Heikkinen. He returns to his old hometown of Savonlinna every spring to take part in the lair count. Heikkinen and his cousin Pertti Kinnunen, who still lives by Lake Saimaa, have both been active lair count volunteers for years. “The survival of the Saimaa ringed seal is important to me. I’m very worried about its future. Sometimes I wonder if the Saimaa seal has any chance at all of avoiding extinction, as the population has been so depleted. But I still hope for the best, and we are certainly doing everything we can to make sure the seals will be swimming around here in years to come,” Heikkinen says.

There are certain precautions to be taken by anyone intending to venture on to lake ice. One spring, While Matti Heikkinen was out counting lairs, an icebreaker crossed the lake behind him, opening a channel through the ice and cutting off his return route. Luckily, he had foreseen that this might happen and brought a boat with him. He placed his skis and rucksack in the boat and rowed back over the open water.

Every lair count volunteer has an assigned area, which they explore with the help of a few others. A total of more than 50 people, half of them volunteers, count the pups around the lake system. Heikkinen, Kinnunen and two other volunteers have about 100 kilometres of shoreline to explore every spring. “In the best years, we’ve found five seal pups along that stretch. In 2003, there was only one. This year, there are three lairs with pups in our area,” Pertti Kinnunen says.

Important task

The volunteers usually explore their assigned areas on skis, regarded as the best way of making nature observations. Snowmobiles, hovercraft and hydrocopters are also used to some extent. The volunteers move around the islands in the lake in spring when the seal pups have already grown big enough to leave their lairs. In this way the volunteers can be sure not to disturb the lairs and the mothers feeding their young.

“The most important task of the volunteers is to look for lairs where seal pups have been born that spring. The surest sign that a pup has been born in a particular lair is the pup's grey fur, or natal hair. There is usually a lot of it in a lair where a pup has been born, because the pup sheds it and then grows a new dark coat while still in the lair,” Koskela explains.

Valuable work

The reason why the new pups and their mothers are counted on the basis of the lairs found is that both the mother seals and pups are very hard to observe on the lake in winter, when visibility is often not good. The volunteers are also asked to collect samples of the seal pups’ natal hair for analysis. It is tested for heavy metal content, for instance, and DNA samples are taken for future examination. The volunteers report all their observations in detail to the experts of the Forest and Park Service.

All in all, the volunteers do very valuable work for the conservation of the Saimaa ringed seal. They are not paid for their help, only their travelling expenses are reimbursed. They sign an agreement with the Forest and Park Service which includes insurance cover for the volunteers themselves during their journeys in search of lairs. The Service also lends the volunteers buoyant survival suits, which are essential apparel since they will be moving over the lake in spring, when the ice can be dangerously unpredictable and weak.

Protective restrictions

If all the seal pups born each spring were to survive, the population of Saimaa ringed seals would gradually grow. The problem is that some 10 to 20 of the pups born each year die as a result of getting stuck in fishing nets. The seals are protected by restrictions on land use and fishing near their breeding grounds. Holiday cabins or permanent homes cannot be built along the shoreline next to the seals’ breeding grounds. Fishing is also restricted in certain areas through voluntary agreements with fishermen.

Conservation biologist Jouni Koskela of the national Forest and Park Service pictured at a seal lair. The lairs are counted in the spring just before the ice melts, as soon as the seal pups are big enough to have left the location. The lairs are counted by volunteers who help with crucial conservation work in this way.

“This year again the use of fishing tackle which could pose a danger to seal pups is prohibited over an area of 400 square kilometres of Lake Saimaa. In practice, this means that the use of any kind of net is forbidden in the area during the critical season for pups, from mid-April to the end of June,” says Jouni Koskela. The Forest and Park Service pays compensation to fishermen for the catches they lose due to measures to protect the Saimaa ringed seal.

About 60% of the seal pups are born within the fishing restriction areas. But that leaves many others that are born in areas where people can fish freely. This puts the seal pups in very grave danger as they frolic about in the water during the first few months of their lives. Seal pups under the age of four months can easily get tangled up in fishing nets.

Helpful information

Active information campaigns have proved to be of great significance in helping to protect the Saimaa ringed seal. “Positive attitudes to the protection of the Saimaa ringed seal have clearly increased over the past years. People who have holiday cabins as well as permanent residents in the area want the seals to continue living on their shores.”