Freshwater seals in Lake Baikal?

Question

I was watching Planet Earth and they said that the world's only freshwater seals live in Lake Baikal. Since Lake Baikal is in Eastern Siberia, they also said that the lake is covered with ice 4 months out of the year, with the ice being about a meter thick. That made me wonder, if there's ice covering the lake for 4 months, what happens to those seals? Do they just stay on top of the ice for all of those 4 months? How will they catch fish then, if the fish is in the water under the thick ice?

Answer 1

The world's freshwater seal is known as the Nerpa or Pusa Sibirica and about 60,000 are living in the Lake. There are tight restrictions on their hunting.

Their main source of food is the Golomyanka or Baikal Oilfish. This moves from the bottom to the top. The Nerpa dig holes in the ice to mate and rear their young, The Nerpa will dive from 10-20 minutes into the water from these holes, and feed on the 65,000 tonnes of Golomyanka, which are easy to spot. They are 15-20cm.

The Nerpal can dive for up to 70 min if necessary. The Nerpal also eats the Omul (Coregonus Migratorius), a type of salmon. The Omul is also eaten by the Golomyanka and people of Baikal. The Nerpal can also eat several invertebrates. They eat with dives.

The Nerpal normally stays on top of the ice.