Lake Baikal is a freshwater lake, more than 2,000 kilometers away from the ocean. Why are there marine life?

Lake Baikal is located in the southern part of Eastern Siberia and was called the "North Sea" in ancient China. Lake Baikal is beautiful and full of mystery. And one of the most incomprehensible puzzles is that Lake Baikal is obviously a freshwater lake, and it is more than 2,000 kilometers away from the ocean. Why are there marine creatures such as seals in the lake?

Lake Baikal has "three oddities"

Open the map of Eurasia, Lake Baikal is like a blue crescent moon, embedded in the mountains of Siberia. There are many theories about the origin of its name, but the most credible one is from the Turkic word "bai--kui", which means "Lake of Plenty".

Lake Baikal is a gift of nature. On the one hand, it refers to the beauty of its scenery. It is known as the "Pearl of Siberia". The lake is clear and charming.

Some people say that they once went boating on the lake, but they bowed their heads and were shocked - the lake water was so clear that you could see tens of meters underwater, and the hull of the boat seemed to be suspended in the air, which was very strange. It is said that when you fill a bowl of lake water, you just need to filter the plankton and you can drink it directly.

In addition to the unforgettable beauty, Lake Baikal has three peculiarities. The first oddity is its huge water storage capacity.

Lake Baikal is 636 kilometers long, with an average width of 48 kilometers and an average water depth of 730 meters, with the deepest point being 1,637 meters. The huge storage capacity and the inflow of 336 large and small rivers such as the Selenga River make Lake Baikal a natural super-large reservoir.

It is understood that the volume of Lake Baikal reaches 23.6 trillion cubic meters, and the freshwater reserves are 8 times that of China, occupying 1/5 of the world! The total area of ​​the Great Lakes in North America is 245,000 square kilometers, and the area of ​​Lake Baikal is only 31,500 square kilometers, but the freshwater reserves of the two are almost the same!

The second peculiarity of Lake Baikal is its "age". Of all the lakes on earth, it is the oldest.

Scientists have pointed out that Lake Baikal began to form in the Jurassic period more than 100 million years ago, and its current appearance was probably shaped 20 million years ago. Compared with ordinary lakes, in terms of lifespan, Lake Baikal is a proper elder.

The third strange thing about Lake Baikal is that the species of creatures in the lake are extremely rich. There are 600 species of plants and 1,200 species of aquatic animals in the lake, 3/4 of which are unique species in this lake.

What is even more surprising is that Lake Baikal is a freshwater lake and is more than 2,000 kilometers away from the ocean, but there are marine life such as seals and sharks in the lake. Why? Why do marine life appear in a freshwater lake? It is said that there are seals, sharks, sponges and other creatures commonly found in the sea in Lake Baikal.

In the past, some scientists believed that the reason why Lake Baikal has marine life is because it used to be an ocean. In the Mesozoic Jurassic, east of Lake Baikal, there used to be a vast Trans Baikal Sea.

Later, due to crustal changes, only inland lakes remained, which is today's Lake Baikal. At that time, Lake Baikal was still a salt water lake, and after the continuous dilution of rain and river water, it became a fresh water lake. However, this claim was later refuted by new findings. Geologists pointed out that relevant materials show that there is no Mesozoic sedimentary layer in Lake Baikal, only Cenozoic sedimentary rock layers.

This discovery means that Lake Baikal has always been terrestrial and has not experienced an oceanic period, and it is a fault lake formed during crustal rifting.

So, why are there marine life in the lake? In fact, there are many misunderstandings. For example, sponges, there are more than 10,000 kinds of sponges in the world, most of which are distributed in the ocean, and about 20 kinds are distributed in clean lakes and gentle streams.

The sponges in Lake Baikal are freshwater species. The statement that "there are sharks in the lake" is also a misunderstanding. It is true that some sharks can live in freshwater rivers and lakes, but in Lake Baikal, there are no sharks at all.

The rumored shark actually refers to the Dufu fish. Du Fu fish is also called big head fish. The head is large and flat, and it gradually becomes smaller towards the tail. There are more than 300 kinds of Du Fu fish in the world.

So, what about the seals? This is not a misinformation, seals actually live in the lake. At the end of May 1999, a large number of seal carcasses, as many as 42, were found on the shore of Lake Baikal.

Where do lake seals come from? Scientists believe that the real marine life in Lake Baikal is only seals and Omur fish. These creatures entered the Yenisei River from the Arctic Ocean and then swam up the lake along the tributary Angara River.

However, why do they leave the sea and not return, but settle in freshwater lakes? Scientists speculate that it's not that the seal doesn't want to go back, but that it can't go back.

With the end of the ice age, the Yenisei River narrowed and became shallower, making it difficult for seals to travel from the river back to the sea, and had to stay in the lake, and gradually adapted to living in fresh water for a long time, becoming the local Baikal seal.