I almost saw one on a hot July day.
     In a narrow strait, between an island and a few large boulders, one of the small, black, round stones suddenly snorted and then submerged.
     My two friends, a few metres behind me, whispered excitedly, almost jumping up and down in their kayaks: 'Didyouseeitdidyouseeit?!' No! I had been looking in another direction.
     I had no luck later either; the Saimaa ringed seal (Phoca hispida saimensis) is not easy to spot. This endangered species, living only in Lake Saimaa, in south-eastern Finland, is an elusive, cautious animal that even sleeps in the water. In high summer it quietly clambers onto its favourite rock late in the evening to rest, but its dark stone-coloured, ring-patterned coat is a great camouflage.
     The best chances of encountering a seal in the Saimaa waters are in late May, when these endearing, long-whiskered, sleeping-bag-shaped creatures shed their winter fur. Sunbathing on the rocks is a popular pastime, because it quickens the moulting process, so the seal prefers not to escape into the water quite as quickly as at other times.
     It is easy, I myself have noticed, even for an ignorant urbanite to become enchanted with the quiet, vast, uninhabited waters of the nature conservation park; the Haukivesi area is, in addition to seals, richly populated by divers, grebes and goosanders. They also tend to submerge to avoid approaching humans, but compared to the shy seal, the birds are easy to spot.
     There are 13,700 islands in Saimaa, the fourth largest lake in Europe; it has the longest lacustrine shoreline in the world, almost 15,000 kilometres. The ringed seal only lives in the least inhabited parts of Saimaa, but there is plenty of space for the seal population to grow - it is now approximately 280. Before the species became protected by law in the mid-1950s, it had become almost extinct; seals were hunted mostly for the alleged damages they caused to fishermen, not for their flesh, but their skin and blubber were used to some extent. A seal eats around 1,000 kilos of fish per year, mostly small species with no commercial value to humans. But because the seal is clever, it is known to eat small vendace straight off from the net by biting each fish into half. The number of professional fishermen has diminished radically since the mid-20th century, but fishnets are still the most common cause of death of young seals. To prevent this, net fishing is now prohibited all summer in some areas of Saimaa.
     Environmental pollution, mainly from mercury, DDT and PCBs, used to be a real threat to the remaining seal population; the Saimaa waters have, however, become cleaner during the past decades, and the number of seals has been slowly growing. But it is the most highly priced species of the Finnish wildlife: murder one, and you will pay a fine of 9,755 euros if you get caught.
     Approximately 11,500-12,500 years ago, near the end of the last ice age, seals inhabited both Saimaa and Lake Ladoga, now in Russian Karelia; both lakes were still parts of the Baltic sea. When the ice began to retreat and the land began to rise, they were cut off from the sea. Some 9,000 years ago the ringed seal got 'trapped' in Lake Saimaa. The closest relatives of this relic species today are to be found in the Baltic and in the vast Lake Ladoga.
     The freshwater cousins resemble each other a great deal, but the Ladoga seal (Phoca hispida ladogensis) is a noisier, a more sociable animal who likes to hang out in a crowd, whereas the silent Saimaa seal does not care for company - perhaps it has become a loner, because the Saimaa seal population was hunted to near extinction.
     Hyle. Saimaan oma norppa is a fascinating story about the Saimaa ringed seal, in Finnish, norppa (the word is originally Russian, nerpa) or hyle, which is a colloquial name in the Savo dialect. The book contains everything you could ever wish to know about a wild animal and its natural surroundings: it provides well-written and copiously illustrated information on biology, evolutionary biology, physiology, history, geography, lakeland landscapes and the environment. No wonder the authors, all specialists in seal research, received a State Award for Public Information for this book in 2005. The experienced photographer Juha Taskinen is devoted to the hunting of seals with his camera.
     Thanks to modern technology, we now know plenty about the seal's fishing and sleeping habits - take, for example, a young male called Osmo: on several occasions, clever scientists have attached a transmitter to his sleek back (it comes off each time Osmo moults). So we now know that in summer Osmo likes to enjoy a long brunch between three and eight a.m. before he embarks on leisurely swimming tours and that he always returns 'home' to sleep. An adult seal contains 11 litres of blood on average (humans have 5 litres), and their haemoglobin level is 250 (milligrams per litre; humans' level is 120-170 on average); plentiful oxygen in the blood makes long dives and sleep in the water possible. Seals may live as long as 30 years, and they seem to be very faithful to their home waters. Another test seal called Ritva, XXXL in size, weighing at least a hundred kilos (an average-sized adult seal weighs around 60 kilos), has given birth to at least one exceptionally big and strong pup.
     Saimaa freezes over in late October, and the ice and snow melt in late April. It is amazing that the seal is able to survive by fishing under the ice for almost six months. It makes several breathing holes in the ice and digs lairs under the snow - not unlike igloos, which are relatively warm - near the shore on the ice. The female gives birth in the lair in late February or early March. Save for short dips from the lair under the ice, the pup needs to stay out of the water for a few weeks in order to gain enough fat to maintain an adequate body temperature. But the pup grows fast: its mother's milk contains an astonishing 40 per cent fat. In summer the mother seal instructs her offspring how to fish - and it needs to learn, because it will be on its own by autumn.
     According to the latest count, some 60 new additions to the Saimaa seal population will be studying the secrets of fishing in summer 2005. It seems that the norppa family is growing slowly but steadily.
     No wonder that in the national epic Kalevala the seal is called 'the water dog': the whiskered, four-flippered predator does have canine features. Research has proved that the pinnipeds - various seals, sea lions and the walrus - are descended from the original form of carnivores. The seals' distant feline and canine relatives seldom spend time in the water, but among ursine and musteline mammals, biologically closer to the pinnipeds, there are also excellent swimmers. Among them are the polar bear - on whose menu the seal is the main course in Arctic areas; in Finland, the seal's only serious enemy is man - and the truly aquatic sea otter which even sleeps in the water.
     I have never been attracted to bird-spotting of the passionate kind, but, thanks to Hyle, I now know so much about the fascinating water dog of Saimaa that I want to jump into a kayak again and start doing some serious exploration. There is something thrilling in the idea of meeting someone so prehistorically indigenous that he has been around for at least 9,000 years - and the magnificent sight of a whole osprey family soaring in the sky is a considerable bonus.