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Origin & Development |
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History of Lake Baikal |
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Lake Baikal Climate |
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Fauna & Vegetation |
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Water of Lake Baikal |
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Recreational Areas |
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People of Lake Baikal |
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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 nerpa 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 fresh air for almost 70 minutes. According
to the observations of workers of the Limnological Institute, nerpa is able to dive at
a depth of almost 300 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 nerpa has 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 has been attracting people to the Baikal shores. Once nerpa was
used as an object of barter and was also regarded as a totem.
Nerpa 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.
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In the lifetime of a female, after a gestation period of 11 months, it can give birth
to about twenty young ones. In winter time, when the lake 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. As usual seal calves are born at the end of winter
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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 northern section. 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.
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.
Nerpa 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.
The average daily intake of a grown-up nerpa 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.)
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