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Lake Baikal Seals - Nerpa
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Baikal is one of the few continental reservoirs inhabited by "nerpa" (the Baikal seal).
It is still a great mystery how seals appeared in the centre of the Asian continent, if its relatives
live in the northern arctic regions. Some scientists consider that it was pushed southward from the
Arctic Ocean by advancing polar ice during the Ice Age when oceanic waters carved out the Yenisey valley
up to the mouth of the Tunguska River. Baikal seals are known to go up rivers and rise rather high up
with their streams, and sometimes they may even take an overland trip from one river to another. Add
to this fact, the chromosomic analyses and other data are in favour of the nerpa being an arctic-sea seal.
Anyway, there are many differences that the nerpa has to other seals. First, Baikal seals are more graceful,
especially females. Second, they differ from others by the silver-grey colour of the skin. And, finally,
they have 2 more litres of blood which enables the nerpa to do without air for almost 70 minutes. According
to the observations of workers of the Limnological Institute, Baikal seals are able to dive at a depth of
almost 400 m.
Lake Baikal forms an ideal habitat for nerpa - plentiful food, mainly
golomyanka fish and bullheads; an ice regime that creates the optimum conditions for nerpa's breeding and
moult cycle, and rather large and deep water body. Since ancient times Baikal seals have
been an important resource for man. It valued for its wonderful fur, median fat and soft meat. According to the
archaeologists' data, since time immemorial nerpa seal has been attracting people to the Baikal shores. Once nerpa was
used as an object of barter and was also regarded as a totem.
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Nerpa seal is a big animal, it grows about 120-150 cm long and can weigh as much as 100-120 kg; it has a long life span.
Specimens that appear to at the age of 50 and even older have been found.
In the lifetime of a female, after a gestation period of 11 months, it can give birth to about twenty pups.
In winter time, when Baikal is covered by the thick layer of ice, the seal makes holes in the ice by its sharp claws. Nearby,
in a snowy den, it gives birth to one or, rarely, to two seal-calves. At first, they are of yellow-green colour. Two weeks later
they turn white, and later they acquire a noble silver-grey tint of colour. Usually Baikal seals are born at the end of winter
and at the beginning of spring. The seal-mother suckles her young ones for one and a half months to two months.
Seals live throughout Baikal but mostly in the north basin. In summer time the seals are dispersed all over the lake.
In late autumn and at the end of spring the animals keep themselves to ice floes.
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Two centuries ago Peter Simon Pallas wrote sorrowfully that "through spears and swords Baikal has been damaged
irreparably, and the nerpas are not to be seen already in the South Baikal..." |
The seals usually spend the winter under ice. Each animal keeps open some air-holes. Often they are
well hidden by snow-drifts or ice hummocks. Thus, it is an out of sight lair ("logovo"), where nerpa rests.
Baikal seals feeds mainly at night-time, as golomyanka fish, its favourite food, only concentrate after dark in the upper
layer, 100 m deep, which is accessible for nerpa. At daytime the fish submerge to great depths.
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The average daily intake of a grown-up seal is about 3-4 kg of fish. So, throughout the year the nerpa eats up more than a ton of
fish, mainly golomyanka. Man has often accused nerpa of aiding the extinction of omul. But the pursuit of omul requires
considerable energy on the part of the seal. And nerpa prefers when available, the rather immobile golomyanka fish an bullheads.
Nerpa is the only mammal endemic to Lake Baikal. At present the number of seals is estimated at around 60 000 heads (according to
information gained by researchers E. Petrov and M. Ivanov, nerpa's population is no less than 100,000 animals.)
More information about Baikal Seals:
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