Why there are marine animals in Lake Baikal

This remains to be studied, and remains an unsolved mystery.

The following is an excerpt from Know:

There are theories that the ancient Baikal is not a sea, but a developing ocean. Now Lake Baikal is expanding at a rate of 2-3 centimeters per year, which is incredible! The expansion of Lake Baikal is the result of the movement of the earth's crust, when the Indo-Australian plate is vigorously squeezed and embedded in the Eurasian plate, the broken part of the Eurasian plate forms the Amur plate, and Lake Baikal is the rift between the Eurasian plate and the Amur plate.

Its age and rarity make it one of the regions with the world's largest variety and rarest freshwater fauna, which is of inestimable value to evolutionary science. At the same time, Lake Baikal is one of the most biologically diverse lakes in the world with its diverse variety of native animals and plants. There are still many unsolved mysteries about Lake Baikal.

For example, the water of the lake is not salty at all, which means that it is not connected to the ocean, but it is inhabited by authentic marine life, seals, conchs, fish and lobsters. Lake Baikal is home to the world's only freshwater seal. In winter, seals bite through holes in the ice to breathe, and since seals generally live in seawater, it was believed that Lake Baikal is connected to the Atlantic Ocean by an underground tunnel.

In fact, the seals may have come up the river to Lake Baikal during the last ice age. Another example is that there are tropical creatures in Lake Baikal, such as Baikal mosses, whose close relatives live in lakes in India, Baikal leeches can only be seen in freshwater lakes in southern China, and Baikal clams only live in Lake Okrid in the Balkan Peninsula.

Will the lake be connected to the sea?

Lake BaikalA very beautiful lake, not onlyThe largest reservoir of freshwater resources on Earth, and also haveAbundant animal and plant resourcesThe most surprising thing is that it is obviously a freshwater lake, but it is insideThere are some marine creatures living there, such as:Seals, sharks, sponges and conchsWait.

You must know that the biggest difference between seawater and freshwater is the difference in salt contentIn order to maintain osmotic pressure, the salt content of cells in the body is generally relatively high。Therefore, when marine life is suddenly released into fresh water, most of the marine life cannot survive; Conversely, freshwater organisms cannot survive in seawater.

There are so many kinds of marine life in Lake Baikal, the same kind that live in the ocean, simply cannot adapt to the freshwater environmentThe origin is very mysterious, and now there are 2 explanations:

First, the sea retreats from the relics

According to geological studies, Lake Baikal was formed in:Tectonic plate collisions 25 million years ago, Soviet scientistVeretshkinIt is believed that in the Jurassic period the area east of Lake Baikal once had a vastTransbaikal Sea。Later, due to crustal changes,The sea retreated, leaving Lake Baikal。With the continuous addition of rain and river water, the original salt water has become fresh water.

And some of the marine creatures left behind in Lake Baikal, most of them could not adapt to the fading of Lake Baikal and died one after another, butA few species, such as seals and sharks, gradually adapted and have survived until now

2. Remnants of the Tertiary of the Cenozoic Era

Since65 million years ago, after an asteroid hit the Earth causing the extinction of the dinosaursThe Earth has entered the Cenozoic Era, but also let the birth of some new species, during which there were someNew species such as freshwater seals and sharks emerge, Baikal is also home to these creatures.

Due toThe Cenozoic Tertiary experienced glacial coverIn many places, seals and sharks are either extinct or have entered the marine life; Lake Berga due to itVery deep and wide, and therefore andThe seals and sharks that lived in it survived without being completely frozen by the glacierand until now.

So, many people believe that these marine creatures of Lake Baikal, areThe species left over from the Tertiary period of the Cenozoic Era originally lived in freshwaterMiddle.

The marine creatures that live in Lake Baikal are different from those in the sea, and although they are the same species, they have adapted to the environment of Lake Baikal over a long period of time.

Because this freshwater lake is very large, the area is vast, and the water volume is abundant, and it is particularly deep, so there are these marine creatures.

The seals and sharks in Lake Baikal are actually just one of the marine seal sharks, and they are no longer the same as the seal sharks in the sea, they are just a kind of seal sharks in freshwater.

Say that there are a lot of crucian carp in Lake Baikal, carp and grass carp are about the same, and there are absolutely no whales, sharks and seals, don't talk nonsense.

Because the lake was once connected to some oceans, and then it became like this with the geological changes.

It should have come in from the Arctic Ocean along the Yenisei River.

This is because rivers, rivers, seas, and lakes are all connected, and some marine life is likely to appear in some other lakes, so it is not unusual at all.

That's because the underground river water will have a certain circulation, so this situation will occur, which is also a relatively normal phenomenon.

There is no way to answer this question until now, because this phenomenon does not exist in other lakes at all.

Lake Baikal is also fed by groundwater and precipitation from the bottom of the lake. This is a stratigraphic fault zone in Europe, Asia, and is frequent. ** To Lake Baikal, the lake area is replenished with a large amount of groundwater.

More than 300 mineral springs have been discovered, and 400,000 cubic meters of mineral water are spewed out every day. According to previous research by scientists in the USSR, this is the main ** of fresh water on Lake Baikal.

Lake Baikal was once a saltwater lake. This is the remains of the ancient Baikal Sea. Later, due to the large amount of fresh water from the surrounding rivers, it became a freshwater lake.

The fresh water of Lake Baikal comes from rivers and melting glaciers in the surrounding mountains. There are also many medical hot springs in the lake area, about 300 of them, and the water volume is about 40 cubic meters overnight. Lake Baikal is the homeland of the Eules, they wrote:

The sky is vast, and only when the wind blows, can you see the cattle and sheep.

The lake covers an area of 10,000 square kilometers, but its water storage capacity has reached trillions of cubic meters, accounting for 17%-20% of the world's total water volume in mobile riverbeds and freshwater lakes. It has more lakes than all lakes in North America and 33 times more than all lakes in China, and can provide drinking water for 5 billion people. The Selenga River, originating in Mongolia, was named the Chinese Fairy Goose River in the Tang Dynasty and the Xue Lingge River in the Yuan Dynasty.

The river is mainly fed by groundwater, snow-capped meltwater and rainwater, so it is abundant even in the dry season. In the summer, excessive rainfall can sometimes lead to the flooding of the Selenga River. The Selenga River is called the filter of Lake Baikal, because there are many aquatic plants in the river, which allow sediment to settle down and prevent too much sediment from entering Lake Baikal.

The abundant water from the Selenga and other rivers dilutes the minerals in the Baikal lake, so the mineral content of the lake is not high.

We know that even freshwater lakes contain minerals, but in small quantities. When the water in the lake evaporates to a certain extent, even freshwater lakes can become saltwater lakes. That is, when the evaporation of a lake is greater than the amount of precipitation and the amount of water injected by the tributaries, the lake forms a saltwater lake.

For example, the annual evaporation of Qinghai Lake in China far exceeds the amount of precipitation and the amount of water injected by its tributaries, causing minerals to accumulate in the area and eventually form a saltwater lake.