Seal Native to Lake Saimaa
The Saimaa Ringed Seal (Pusa hispida saimensis) is one of the few fresh-water seals. Due to the melting of the ice sheet and as the land uplift broke the connection to the Baltic Sea, the Saimaa Ringed Seal became isolated in Finland's largest lake 8,000 years ago. As it adapted to life in the murky waters of the labyrinthine Lake Saimaa, its brain and eyes grew larger than those of its near relatives. The Saimaa Ringed Seal is endemic to Lake Saimaa, and it is not found anywhere else.
The Saimaa Ringed Seal spends most of its life submerged. It can even sleep under water. In May, during the moulting season, seals enjoy lolling on lakeshore rocks and islets drying their fur. The seals usually have their favourite spots, where they can be spotted every spring. If you find a seal lying on a rock, do not approach the animal and scare it. With some luck, you may be able to observe its life for years.
After the moulting season, seals return to the water. In the July warmth, only an occasional seal head popping to the surface is evidence of the existence of this mythical being.
Seals do not Suffer from Decompression sickness
The Saimaa Ringed Seal is a skilled diver and adapted to life in the water. It navigates through the maze of islands and islets in Lake Saimaa with the help of its sight and whiskers, which it uses as sense organs. The seal's hypodermic fat layer functions as excellent insulating material in the water, and the large hind flippers enable quick moves when foraging.
The seal was the first professional fisher in Lake Saimaa. An adult seal eats about 1,000 kilos of fish a year. Its body mass, particularly the amount of fat, varies heavily, depending on the season. The seal is at its fattest in early winter before the lake freezes and at its thinnest in early summer, after the breeding and moulting seasons. When moulting, seals fast for most of the time.
The Saimaa Ringed Seal population is growing slowly. The seals only reach sexual maturity at the age of 4 to 6 years and usually give birth to one pup a year. Due to high mortality in the younger age group, particularly, the life span of a seal is often under ten years. With good luck, a seal may live to be over thirty.
The Saimaa Ringed Seal Faces many Threats
Due to hunting, environmental toxins, changes in the water level during the breeding season, and by-catch mortality, the seal population collapsed towards the end of the 20th century. Some of the threats have been defeated, and the Saimaa Ringed Seal population has been growing slowly in this century. However, there is still plenty to do to secure the future of the seal.
- Hunting. The Saimaa Ringed Seal was hunted and a bounty was paid for killing them until the 1940s. Hunting was forbidden for good and the Saimaa Ringed Seal was protected by a decree in 1955.
- Environmental toxins. The high mercury concentrations in Lake Saimaa in the 1960s and 1970s, in particular, had a detrimental effect on seal reproduction.
- Water level fluctuation. The great variation in the water level of Lake Saimaa used to destroy the winter lairs of the seals, until in 1991, an agreement of regulation of the outflow was signed to stabilize the water level fluctuation during the ice covered season.
- By-catch mortality. The adoption of nylon gill nets in the 1960s has been disastrous for the seal population.
The greatest threats today:
- By-catch mortality. Pups, in particular, still get entangled in gill nets and drown in fish traps which have a wide opening.
- Climate change. A snowy winter is essential for the survival of seal pups.
- Small population. If seals are too closely related, this weakens the gene pool.
- Disturbance during the breeding season. Disturbing the seals during the breeding season may result in the death of the pup.
- Building on shorelines. The increase of year-round living on the shores of Lake Saimaa decreases the amount of areas suitable for seals as breeding and resting sites.
Metsähallitus and the Saimaa Ringed Seal
Metsähallitus is committed to protecting the seal on the areas owned by the government. Metsähallitus Parks & Wildlife Finland is responsible for the conservation and population monitoring. Various authorities, nature conservation organisations, researchers and more than a hundred volunteers participate in the conservation effort. The more intense conservation measures have produced good results. In 2016, 86 pups were born, a new record.
Concrete measures to protect the Saimaa Ringed Seal began in 1955, when the seal was protected and its hunting was forbidden by a decree. The first fishing and hunting restrictions in areas populated by the Saimaa Ringed Seal came into force in the 1980s. Today, the Saimaa Ringed Seal, its winter lairs and basking sites are protected by the Nature Conservation Act.
Restrictions on landing on shores, and other restrictions on access, have been imposed in national parks and other protected areas. The requirements of the seal are taken into account in land-use planning, and the use of fishing gear dangerous to the seals has been restricted.
The monitoring of the population helps to assess the effectiveness of the conservation measures taken and to respond to potential threats quickly. The conditions at the breeding habitat, birth rate and the causes of death are monitored annually.
The Saimaa Ringed Seal will continue to grace us with its presence, if we all participate in the conservation effort! The future generations will then also be able to spot a seal basking on a rock or diving in the open waters.
The Saimaa Ringed Seal and I
We can all participate in the conservation of the Saimaa Ringed Seal. By-catch mortality is still the most serious immediate threat to the seal population. Pups, in particular, easily become entangled in gill nets and may get caught in a fish trap, if the opening is too wide. See below for instructions on seal-friendly fishing.
The climate change is another serious threat to the Saimaa Ringed Seal. Poor snow and ice conditions hinder the breeding success of the seal. By staying away from the ice of Lake Saimaa, especially the shoreline of islands and islets, and by keeping dogs on a leash when the lake is covered by ice, you can help the Saimaa Ringed Seal breed – particularly during mild winters with poor snow conditions, when the pups are not protected by a snow lair. By cutting your consumption and by making environment-friendly choices, you can also improve the living conditions of the Saimaa Ringed Seal.
Only use a fish trap in which the maximum width of the opening is 15 cm.
In the breeding areas of the Saimaa Ringed Seal (norppakartta.wwf.fi, in Finnish), only fish traps in which the maximum width of the opening is 15 cm, even when stretched, may be used. The stretching of the trap opening may be prevented with special stoppers or with cable ties, for example. Under the Fishing Act, fish traps must be clearly marked and equipped with the owner's contact information. Also remember to get a fishing permit.
Do not use gill nets between 15 April and 30 June. Check the areas with fishing restrictions from the WWF seal map (norppakartta.wwf.fi). A good half of the waters of Lake Saimaa are protected by restrictions. Also remember that gill nets are also a hazard to the Saimaa Ringed Seal outside the restriction periods, as well.
Keep your eyes open when boating on Lake Saimaa. When you go boating on Lake Saimaa, observe your environment. It may be challenging to spot a seal head in the dark water.
Avoid islets and snowdrifts on shores. If you move on the ice of Lake Saimaa in winter, avoid islets on open stretches of water and spits of land, as they may hide a seal lair. Also, keep your dog on a leash.
Report Seal Carcasses
It is essential for the conservation of the Saimaa Ringed Seal that all dead seals are examined. The age and sex of the dead seal, often also the cause of death, can be determined from the carcass. This is important information for the population monitoring.
- If you come across a seal carcass, make sure that it will not be washed away by waves.
- Inform Metsähallitus in Savonlinna about your find without delay, tel. 0206 39 5000, or the police. Provide your name and address and the time and place of the find.
- You can also report other observations relating to seals in Lake Saimaa to Metsähallitus by email saimaannorppa(at)metsa.fi.
Thank you for your help!
More information on the Saimaa Ringed Seal and the LIFE project