Text / Picture Angler Original
preface:
The beautiful Lake Baikal is located in the middle of present-day Siberia, and the blue water of the lake bends like a crescent moon, like a blue eye embedded in the vast Siberia. Known as the "Eye of Siberia". If the earth is regarded as a "home", Siberia is the "living room" of this home. Lake Baikal is a beautiful and super large "fish tank" in this living room. Nature is the fish farmer, a super "big player". Any fish master compared to the big player of nature immediately looks dwarfed and incomparable!
This super "fish tank" not only raises freshwater fish, but also many marine life, such as the seals that only exist in the ocean. If you take the analogy of fish farming, nature, the "big player", only loves the super "fish tank" of Lake Baikal. Throw a few streets off the three great lakes of Africa. What's going on here? Because Lake Baikal is a "fish tank" in the true sense, all the supporting settings related to fish farming, nature has prepared for Lake Baikal. The most important thing is that nature has prepared oxygenation equipment for this large "fish tank" that is more than 1600 meters deep, so that its bottom is full of infinite vitality. Let's use the principle of fish farming to explain its ecological mechanism in detail, and understand its mysteries and some unsolved "mysteries" together.
Key points:
The origin of the beautiful super "fish tank" Lake Baikal
Strange fish and creatures in Lake Baikal
The principles of fish farming are used to explain the ecological mechanisms of Lake Baikal
The mystery of the seal survival of Lake Baikal
<h1 class = "pgc-h-arrow-right" > the origin of the beautiful super "fish tank" Lake Baikal</h1>
Nature's magic has created the super "fish tank" of Lake Baikal
About 20 to 30 million years ago, a collision and squeeze between the earth's plates occurred. Several "scars" were torn on the ancient continent, one in what is now east Africa, forming the Great Rift Valley and the Three Great Lakes of East Africa; one is where Lake Baikal is now located. This kind of lake is called "fault lake", and it is characterized by its extremely deep depth, reaching more than 10,000 meters deep. Then 2 to 2.5 million years ago, an orogeny arose, and mountains formed on the left and right sides of Lake Baikal. To the north is the Central Siberian Plateau and to the south is the Mongolian Plateau, so that a basin-type super large "fish tank" is built. After a long period of rain and sediment impact the landfill became shallower, the bottom sand of this fish tank was also available. The original depth of 10,000 meters has become 1626 meters.
This super large aquarium is about 600 kilometers long and up to 80 kilometers wide, in the shape of a crescent, about the size of Belgium. If you drain Lake Baikal, you will see the following figure, which consists of three different shades of the lake bottom. Earthquakes often occur here, and a single major earthquake causes the lakebed to drop by 3 to 5 meters, cracking 2 centimeters wide every year. In other words, the fish tank is still getting bigger and deeper.
Cross-sectional view of Lake Baikal
The historical changes of Lake Baikal have made the super "fish tank" change owners several times
A song "On the Shores of Lake Baikal" allows us to appreciate the artistic conception of Russian style, if the time goes back more than two thousand years, the Su Wu who holds the festival of shepherding sheep stands in the cold wind. At this time, its name was "North Sea". Zhuangzi called it "North Meditation", and the earliest naming rights should belong to Chinese. As the stars moved, it became the land of other countries. In 1643, a group of Cossacks came to Lake Baikal and conquered the Buryats (a branch of the Mongols) here. The present-day city of Irkutsk was established on the Angara River. Since then, it has only been a thought in the minds of our people, and today Lake Baikal has been inscribed as a "World Natural Heritage", and in this sense, it also belongs to the whole world.
The extremely beautiful "fish tank" makes people feel like they have come to the planet
The beauty of Lake Baikal is a pure beauty, the ultimate beauty, the beauty of biodiversity. Lake Baikal enters spring in April and summer in June, and although the temperature reaches 22 degrees, the lake water is only 10 to 15 degrees Celsius in summer, and the lake water is cold all year round. In summer, the lake is crystal clear and has a visibility of up to 40 meters. There are many small towns along the lake, which are connected by the road "Gorky Avenue" along the lake, and Olkhon Island is a perennial inhabited island.
The winter ice surface of Lake Baikal gives people a kind of star-like, breathtaking beauty. Dreamlike bubble ice, some as big as a bowl mouth, some like countless rays, when approaching the ice surface, instantly frozen.
Lake Baikal in summer, with its turquoise waters
Lake Baikal in summer
Wooden houses with a Russian style, scattered around the lake to form a small town.
Greetings from the forest fox.
fox
Grassland slopes, nurturing thousands of years of nomadic civilization.
pasture
The vast surface of Lake Baikal, is it a lake or a sea? No wonder the ancients called it the North Sea, where seabirds and swans come to inhabit.
Is the surface of Lake Baikal a lake or a sea?
seabird
swan
This is not the Arctic, this is the ice floes of Lake Baikal, and in May, the ice floes that have not completely melted attract baby seals to come up and play.
Baikal seals
Lake Baikal in winter, the most beautiful island of Olkhon
In the faraway siberia, Olkhon Island is synonymous with the cold, like a dream in the world, where ice cracks, bubble ice, ice rays, ice milk holes, and large layers of blue ice cubes are gathered in winter.
Ice cave on Olkhon Island
In winter, the biogas bubbles of different sizes in the lake rise from the bottom of the lake, and when they are close to the water surface, they are sealed in the ice by the rapid temperature difference, and the large ones form a continuous bubble ice, and the small ones leave a trajectory of movement, like ten thousand sharp arrows shooting from the bottom of the lake.
Bubble ice
In Olkhon Island, the depth of the water surface is not the same, the temperature difference of the water body is also different, and the phenomenon of thermal expansion and contraction makes the ice cube fold and arch, because the ice cube almost does not contain any impurities, and under the refraction of the sunlight, it emits a blue glow, a suffocating beauty that makes people feel that they are from the planet.
The glowing blue ice on the surface of the lake
<h1 class = "pgc-h-arrow-right" > ii. Strange fish and creatures in Lake Baikal</h1>
There are 600 species of plants and 1200 species of aquatic animals in the waters of Lake Baikal, 80% of which are endemic to Lake Baikal, forming a unique biome in the world. There are a variety of molluscs, sponge creatures, and rare animals such as seals. Among the lower animals there are more than 200 species of endpods and more than 80 species of flatworms. Giant flatworms with a body length of 38 cm have been caught in the lake.
End-legged mammals such as hook shrimp are the dominant species of the bottom. Stone leeches, convex bean snails, lake bulbs, bulbs, rockers and multipods are the dominant species in submerged plant areas. Bulbophyllum and bulbous clams are dominant species in the floating leaf area. Waterworm and bulbous clams are dominant species in anhydrous grass areas. These demersal flora and fauna provide a rich food source for fish. There are about 50 species of fish in Lake Baikal, belonging to 7 families, the largest being the Dufacey family, with about 25 species. Then there are salmon, fennel, sturgeon and so on. There are two species of fish that are very important in Lake Baikal, one is the Baikal oil fish, which is the food of seals, and the other is the important economic fish autumn salmon.
In particular, it is worth mentioning an animal called a sponge that plays a vital role in the lake. This is a columnar animal, not a plant, oh, the local people call it "bone card". Often symbiotic with algae, it is a common multicellular animal in the Paleozoic ocean. Commonly found in the deep sea, with porous filter feeding, originating in the Cambrian Period 570 million years ago, the sponge of Lake Baikal is called lubao sponge, which can grow to 1 to 1.5 meters high.
Fish of Lake Baikal
Du father fish
Also known as the bighead fish, Scorpiopoda, Dufaceyidae. The northeast region is called the old man fish and mainly inhabits the northern hemisphere. There are about 300 species of Dufar in the world, but the Dufar fish in Lake Baikal is unique and can live at depths of 100 to 1600 m. This fish is thought to be a pond bass by many people, and its common name is perch.
Fetal Baikal oil fish
Baikal oilfish is a very unique fish species in Lake Baikal, about 20 cm long, it is the main food source for seals, and the population is very large, accounting for 80% of the total number of fish in Lake Baikal. This fish is not suitable for human consumption, and 40% of the whole body of the fish is made of fat. The whole body is transparent, and it has dragonfly-like wings. Hiding in 1,000 meters of deep water during the day, you can only float and eat plankton at night with the current. Therefore, the seals of Lake Baikal wait for the night to catch oil fish. This fish is a typical hard-working type of fish, eating only a little food, but can produce a lot of fat. For the survival of seals is really heartbreaking.
Baikal oil fish is very unique is that it does not have a real sense of the movement system, can not swim everywhere, can only swim with the current, when floating to a certain water layer, the water temperature exceeds 7 degrees Celsius, it has to quickly dive with the water. Otherwise, the oil in the body will melt away. Baikal oil fish subverts the fish spawning pattern, it is one of the few fish that is directly born, which is very similar to mammals, but small fish do not drink milk, and can catch 3,000 small fish at a time. Before the Siberian oil reserves were exploited, the fish was also used to refine fuel oil.
Omur fish (autumn salmon)
This is the most important economic fish in Lake Baikal, known locally as "Omley fish", the scientific name is concave white salmon, commonly known as autumn white salmon. Salmonids, a species of salmonid in the genus White salmon, are similar to the tall whitefish farmed in many lakes in the north, except that their eyes are concave.
Omur fish are typical cold-water fish that grow very slowly and take up to 10 years to grow to 1 pound. Fishermen in Lake Baikal often use wooden skewers to wear and frame them on pine wood to smoke or dry them to make smoked fish
Omur fish
Russian smoked fish
Arctic anise
Also known as flower wings, the body is long and flattened, and the snout is blunt and short, similar to the rainbow trout. The bouncing power is amazing, and he likes to jump out of the water like a horsefish to hunt. When the lake thaws in spring, the black Baikal anise takes off, and the splash of water forms a rainbow halo. This fish is widely distributed in northern regions such as Inner Mongolia.
In addition, there are large fish in the lake, such as Siberian sturgeon, pike, salmon. There are also fish of the family Perch family that do not have a defined name.
Siberian sturgeon
Salmon
White spotted pike
Unnamed perch fish in the Baikal Museum of Nature.
Unnamed tropical perch fish
Knowing the above, how does this super "fish tank" of Lake Baikal survive the species? You know, this is not an ordinary fish tank, up to 1600 meters deep at the bottom of the lake actually has life, how to do it? Not to mention that all lakes are like Cameroon's Lake Nyos that produce highly toxic sulfides. At a depth of 1600 meters, it is certainly indispensable to produce a large amount of carbon dioxide gas, which is not adapted to the survival of organisms, why do the creatures of Lake Baikal live well at such a deep lake bottom? To solve this mystery, we still have to start from the principle of fish farming.
<h1 class= "pgc-h-arrow-right" >3. Explain the ecological mechanism of Lake Baikal in detail using the principle of fish farming</h1>
The ecosystem and habitat of Lake Baikal are very complex, but it is easy to understand as long as we combine complex scientific knowledge and superficial fish farming experience.
If we were to raise fish, what should we do? First of all, we have to build a fish tank, lay out the bottom sand and landscaping, and then add water to control the salinity and acid-base PH value of the water body. Then there's the raising of some fish and feeding the fish food. When overfeed, there will be overnutrition and algae; fish will be poisoned by ammonia when excreted and decomposed. What to do? At this time, the filtration system of the fish tank, the tool fish is used on the field, the purpose is to make the water quality become comfortable for the fish. Also, some fish need a certain temperature to overwinter, and in the summer, they need to increase oxygenation, so they use a warmer and an oxygen pump. That's all, let's see how Lake Baikal meets the above conditions.
Food source for fish organisms
Lake Baikal is a super "fish tank", and of course there is no food to raise so many fish and other creatures. Where does the food come from? There are three pathways to food sources, from low to high organisms to establish food chains. There is an important role in this food chain called the hook shrimp. Low organisms feed on bacteria, algae, and plankton; fish feed on plankton and hook shrimp; animals and predatory fish at the top of the food chain feed on other fish; higher animals are decomposed by lower organisms after death. Complete the construction of the entire biological chain.
First, when methane gas from the bottom of the lake comes out of the bottom of the lake, it brings out bacteria. Second, when the temperature rises, a large number of plankton in the lake reproduce. Finally, the delta of the Selenge River is home to a large number of aquatic plants and vegetative detritus. Water fleas and hook shrimp feed on it. Large numbers of fish feed on hook shrimp, oilfish feed on plankton, and seals feed on oilfish. Siberian sturgeon feed on other fish. Loop like this. After the animals die, hook shrimp and bacteria break down their remains. Such a circular mechanism does not have to worry about the pollution of water quality as we do when we raise fish.
Inlet and drainage system
When raising fish, some heavy metals or elements are harmful to fish and organisms, such as marine fish can not be directly added to the tank tap water, need to be exposed to chlorine. How does Lake Baikal filter impurities into the lake's water?
If we look at the figure below, the water source flowing into Lake Baikal is the Selenge River and the melting snow and ice in the northern mountains, and there are as many as 336 rivers, and the Selenge River accounts for the vast majority of the amount of water injected. The northern snow mountain rivers do not cause any pollution because of the crystal structure of the mountains. If the water quality of Lake Baikal deteriorates, there will be only two sources of pollution, namely the domestic water used by the residents of the two cities. It is impossible for Ikukutsk to pollute the lake, because the water level of the lake is higher than that of the river, and the water of Lake Baikal flows into the Arctic Ocean through this river, and it is impossible for the river to flow backwards into the lake.
Inlet and drainage system for Lake Baikal
Look at the inlet river Selenge River, the sediment and nutrients brought by the upstream, bringing organic matter to the fish, and wonderfully, a 700 square kilometer delta is formed at the mouth of the river, full of swamps and aquatic plants, which acts as a large filter. The water that flows into the lake is guaranteed to be clean and the nature is wonderful. This is the inlet and drainage system of this big fish tank in Lake Baikal. If some impurities still flow into the lake, will it have an impact on the lake water over a long period of time? Don't worry, Lake Baikal also has a mature biological filtration system. This is the lake water self-purification system that will be talked about below.
Delta of the estuary of the Selenge River
Baikal's self-purification system guarantees no "violent algae"
Lake Baikal has clear water, visibility reaches 40 meters, and almost no impurities, and the bio-self-purification system plays a crucial role.
Biological self-purification system of Lake Baikal
The aquatic vegetation of the Selenge Delta is known as the "filter of Lake Baikal". The crystal structure of the basin rocks makes it almost impossible to penetrate any material into the lake. These two effects have already been discussed. The focus is now on the role of sponges and hook shrimp.
Starting in April, the ice on the surface of the lake begins to melt, the temperature of the lake begins to rise, and the lake begins to turn green, which is produced by a large number of plankton and algae in the lake, and if the lake continues to remain green, it is what we often call nutrients. General reservoir fish farming is like this, and some reservoirs even turn dark green. When the water temperature of Lake Baikal reaches 4 degrees Celsius, the mass and density of the upper water body become the greatest, at this time, the upper water body is wrapped in plankton and sinks down, and the lower layer of clean and light lake water floats upwards, completing the exchange of water bodies and upper and lower layers, which is not difficult to understand why the river is clear in winter. The work of cleaning up sinking plankton and impurities is given to the following two organisms: hook shrimp and sponge.
(1) The role of sponges
The sponge plays the role of a filter, and friends who have raised fish know the role of the fish tank filter. Its surface, covered with many small holes, can absorb water, in the process of absorbing water, decompose the plankton and organic matter in the water, and then spit out clear water. This sponge in Lake Baikal is very large and numerous, and some grow to 1.5 meters high, forming the underwater forest of Lake Baikal and playing a role in cleaning water quality.
(2) The role of hook shrimp
Lake Baikal is home to a large number of small shrimp, a crustacean about 1.5 cm long, one of the most famous invertebrates in Lake Baikal. They filter the clear water of the lake and filter organic impurities such as plant detritus, decomposed animal carcasses or bacteria for nutrients. The entire Baikal lake region is home to 1.5 million tons of this small shrimp, which is also the food of fish.
Oxygen supply system to ensure that fish up to 1600 meters deep are not short of oxygen
Fish farming friends are well aware that in the summer or raise fish with high oxygen consumption, you need to add an aerobic pump. In the same way, the bottom of Lake Baikal, which is 1600 meters deep, is generally impossible to have biological existence. But there are exceptions to everything, and the exception is that at the bottom of Lake Baikal there are hot springs gushing out like the ocean floor. This hot spring carries a large amount of oxygen, which is transported with the water to all corners of the lake. This is the aeration pump of this super large fish tank.
Thermostat for the super fish tank
Many people think that Lake Baikal is very magical, tropical marine life, such as conch why can survive in the lake in the environment of minus tens of degrees, why leeches that appear in the south can live in Lake Baikal, the reason is also because of the underground hot springs, the ocean's seabed hot springs are as high as 300 degrees, and the hot springs of Lake Baikal can provide the ideal temperature for the organisms after the sediment layer.
<h1 class = "pgc-h-arrow-right" >4, The Mystery of seal survival in Lake Baikal</h1>
To say that the biggest biological mystery of Lake Baikal is the seal, because so far, the scientific community has not reached a consensus on the origin of seals, some say that it is a marine land seal type, and some hold a river trace. Anyway, it is unknown where it came from in ancient times. It's so magical that it's arguing. Only Darwin knew that this was the best proof of his theory of evolution, but unfortunately he had never been here. But The former British Prime Minister Winston Churchill came, and when he came, he lamented: "There is a mystery here."
We don't care where the seal comes from, it really evolved the ability to adapt to the environment anyway. Imagine what to do if an animal that needs to breathe out of the water is sealed under a 1-meter-thick layer of ice? How do seals ensure their breath under thick layers of ice?
The secret is that seals are particularly good at finding cracks in the ice, have a powerful oxygen storage system and strong claws. The powerful oxygen storage system allows it to hold its breath for 1 hour and dive 600 meters deep to catch prey.
When the lake freezes in winter, the seal wants to breathe, and it first finds cracks in the ice. The crack in the ice surface is caused by the thermal expansion and contraction caused by the different water temperatures of the water body, the ice layer here is thin, and the seal takes advantage of its long breath holding and sharp claws to forcefully pull out a hole to breathe. Humans are not as good as animals in the cracks in the ice of Lake Baikal, and many animals know exactly where the ice on the lake surface is safe. In the 1950s, people used to set up temporary train lines on the surface of Lake Baikal through the footprints of animals on the ice.
Ice cracks
<h1 class="pgc-h-arrow-right" > postscript:</h1>
Lake Baikal had already promulgated a law of protection in the time of Peter the Great, and had not suffered great environmental damage, and in the 1930s, the popular slogan of the time was put forward: "We cannot wait for the favor of nature, we must ask nature for it." "Forests are destroyed. It was later corrected, and until now, it has been selected as a World Natural Heritage Site, protected by law, and has not been overexploited. But in recent years, many people have traveled to Lake Baikal, which has caused a certain impact. Please take care of nature and protect fish.
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Some of the pictures originate from the Internet, such as invasion and deletion