There are not many fish in Qinghai Lake, a saltwater lake, mainly because of the following two reasons:

All of these rumored marine life, the so-called sharks are actually the specialty fish of Lake Baikal, a kind of plesiomorphic sculpins; the so-called lobster is actually a freshwater crayfish, which is similar to the crayfish that we usually eat; the so-called sponges Conch actually would have been freshwater sponges and freshwater conch, there are more than a dozen kinds of freshwater sponges in the world, which is not surprising at all.

Only this Baikal seal, which is really a seal, and the distant Arctic Ocean ringed seal have extremely close relatives, DNA comparison is extremely similar. The reason for the Arctic ringed seal's presence here begins with the distant Ice Age. The Yenisei River, which runs through Russia, connects Lake Baikal to the Arctic Ocean.

In the very early days, when the Yenisei River became wider and deeper because of the massive melting of snow and glaciers,some of the sea creatures that live in the Arctic Ocean traveled all the way south along the Yenisei River, and the ringed seals followed their food all the way down the tributary Angara River to Lake Baikal.The abundance of food in Lake Baikal has made it possible for the ringed seals from the Arctic to travel all the way down the Angara River. The ringed seals from the Arctic are delighted with the abundance of food in Lake Baikal.

But one day, when the ice melt ends and the river becomes shallow, the ringed seals suddenly realize they can't go back. The good news is that Lake Baikal is rich in food, deep enough and dotted with islands that give them a place to give birth to their pups. Best of all, seals, as a marine mammal that relies on lungs for respiration, are minimally affected by osmotic pressure, so despite the deaths, after a long period of acclimatization, they eventually survived.

On the one hand, in order to adapt to their environment, and on the other hand, because of too much time in isolation, this group of ringed seals eventually evolved into the world's only species of freshwater seal, the Baikal seal. In fact, two other species of seals survive in Europe, in Lake Saimaa and Lake Ladoga, but they are subspecies and are not reproductively isolated from the ringed seals of the Arctic Ocean, so they are not really freshwater seals in the true sense of the word.

This is mainly because, unlike Lake Baikal and some other saltwater lakes, it neither evolved from the ancient oceans, nor is it connected to them; its salty water forms on its own. Because there have been many fossils of sea creatures from ancient times found on the Tibetan Plateau, some people may think that the emergence of Qinghai Lake is related to the ocean, which is in fact not the case.

The Qinghai Lake was initially connected to the Yellow River, but later, because of the neotectonic movement, the surrounding mountains uplifted, interrupting the connection between the Qinghai Lake and the Yellow River, and the Qinghai Lake became an occluded lake, and coupled with the climate becoming more arid, the evaporation increased, and the Qinghai Lake gradually evolved into a saltwater lake. So the Qinghai Lake itself has little to do with the ocean, and naturally there can be no marine life.

While the cause of Lake Baikal also has nothing to do with the ocean, it is a geological formation of the Great Rift Valley,but it is connected to the Arctic Ocean. In fact, the Caspian Sea is a better example of comparison than Lake Baikal,because another relative of the ringed seal, the Caspian seal, survives in the Caspian Sea.

The Caspian Sea, the world's largest saltwater lake, used to be part of the ancient Mediterranean Sea in ancient times, but later, after the evolution of the sea and land, the land uplifted, and the Caspian Sea and the Dead Sea were eventually detached from the ocean. Thus the Caspian Sea is home to a variety of Arctic and Mediterranean-type organisms in addition to the Arctic ringed seal that swims over from the Volga River.

Also the reason why the Qinghai Lake is so sparsely populated with fish is because of its high salinity, which makes it unsuitable for the vast majority of freshwater fish to survive in. Even the Qinghai naked carp, one of China's five most famous fish with a production of 90,000 tons, has become a protected animal to this day. It can be said that such a large area, as far as fish resources are concerned, Qinghai Lake is really the shame of the lake.

Of course, the Qinghai Lake naked carp to become a protected animal, and human beings once overfishing there is a close relationship, just like the Baikal Lake seals to become a protected animal, but also because of once overhunting and industrial pollution, So environmental protection is very important.