No matter how watery, natural, or artificial it is, it steals our land and delights us with its beauty. We take water from fresh waters, something we cannot do without in everyday life or in production. We swim in the waters, eat next to them, sail on ships on the water, transport cargo . The meaning of vo-do-e-mov in pri-ro-de ve-li-ko. Fresh water is the most important condition for the existence of humans on Earth, and for animals that Those who live in water are also their only home. Water contains everything necessary for life: light, heat, air and dissolved mineral substances.
Plants of ponds
What kind of races are there and what living things live in the fresh waters? Finding yourself near the water in the warm season, you could only observe those of its inhabitants that live on top -no-sti. But life in water is everywhere: near the shores, on the top, and in the thickness of the water, at the very bottom and at the bottom. On the banks of the waters you can see the leaves and stems of ka-my-sha, reed-ni-ka, ro-go-zy, str-lo-li-sta. A small depth allows these pits to attach themselves to the bottom of the water. At a much greater depth there is a white jug and a yellow jug (Fig. 7, 8). Their flowers and wide leaves float on the smooth surface of the water.
How did these plants manage to adapt to life in highly moist soil, where there is almost no acidity? If you look at a cut of the stems of the reed-ni-ka, ka-my-sha, ro-go-za, then you can see the air ducts, which are about -walk in the stems of these plants (Fig. 9, 10).
There are air-breathing channels both in the leaves and in the roots of aquatic plants. A white pitcher and a yellow pitcher have leaves and flower stalks, on which sit flowers, also about the bottom -we air-du-ho-nos-ny-mi ka-na-la-mi, because of which the acidity necessary for breathing- ha-niya. When a flower is picked, a person does harm to the entire race. In the place where water begins to dig into the plant, it leads to rotting of the under-water part and, in ultimately, the entire race is destroyed.
Duckweed grass in the form of small green sheets also floats on the top of the water, but the roots do not stick to the bottom. it's getting stronger, and in the water column there are tiny green waters that can only be seen under a microscope. But their presence changes the color of the water. When there are a lot of them in the water, the color of the water becomes green.
Plants and animals
What role do races play in the lives of many inhabitants of the region? Firstly, green plants, under the influence of sunlight, take carbon dioxide from the air, and you -they put acid into the water, which is necessary for the respiration of all living things. Secondly, in the thickets of water, birds, land-aquatic animals, insects and their lee-chin-ki, fish. There are living things in water everywhere: on the surface and in the water column, on the shore, at the bottom, on aquatic plants . The main connections between living things and races are food. Here are the waters (Fig. 11) running swiftly along the top of the water and hunting for mosquitoes and other small creatures -that's it.
Their long legs are covered with fat underneath, which is why the water holds them. And the aquatic races are inhabited by snails: prud-do-vik and ka-tush-ka (Fig. 12, 13).
Without whom the river cannot live
Without whom the river cannot live? Very small crustaceans, daph-nii and cyclops, live and winter in water. Their number is a little more than a fifth in the book (Fig. 14, 15).
The most notable thing about Daphnia is its long mustache. They wave their mustache, sharply lower, push off from the water and jump up. The cyclo-pa has an unpaired frontal eye, which is why it got its name.
The river cannot live without crustaceans, since they purify the water from bacteria, green algae and small living things that are invisible to the eye. Well, if it weren’t for the crustaceans, the river would quickly be filled with them. Daph-nii and cyclo-py, like other ob-ta-te-li rivers, feed with these or-ga-niz-ma-mi, thereby purifying the water. They themselves serve as food for fish fry, mol-lyus-kam, go-lo-va-sti-kam, li-chin-kam na-se-ko-myh.
Shellfish
Is there really someone living in the river without a head? These are mol-lyus-ki, bez-zu-b-ki and per-lo-vi-tsy (Fig. 16).
Sna-cha-la ra-ko-vi-na, consisting of two longitudinal plates, will lie motionless, then its flaps will a leg opens up and out of it, you have no head or a feather. You-move your toothless leg and stick it in the sand, ra-ko-vi-na b-moving from its place. Moves without a tooth for 2-3 san-ti-meters, stops breathing - and hits the road again. So it goes along the bottom of the river. Food and air come straight out of the water. It opens the valves of the drain and begins to draw in water, then it pours out. The water is full of small animals, they live in the ra-co-vi-well, so without their special -helps-me-me-and-keeps-living. It breathes without any noise and eats, and at the same time purifies the water. And the per-lo-vi-tsa also works. Each day purifies about 40-50 liters of water. Mol-lyus-kov, li-chin-ki na-se-ko-mykh, go-lo-va-sti-kov are eaten by fish, storks, ku-li-ki, ducks. The pla-wu-nets beetle hunts for other creatures, as well as worms, snails, go-lo-va-sti-kov. Lya-gush-ki kor-mya-sya in the coastal parts of the waters, in the main summer-ta-yu-schi-mi on-se-ko-we- mi, and they themselves are food for tri-tonov and predatory fish, perch and pike. Herons, seagulls, winter-rods are hunting for fish and three-of-a-kind.
Life of Cancer
The main food of cancer is plants. But he willingly eats animals, as well as the remains of dead animals. For this reason, crayfish are often called sa-ni-ta-ra-mi vo-do-e-mov (Fig. 17).
Cancers change a lot throughout their lives. The crayfish's sense organs are developed beautifully, your eyes move forward on thin stalks and stand from a huge number, 3000, tiny eyes. The short pair of antennae are the organs of smell, and the long ones are the axes. If a predator grabs a crayfish by its claw, then the crayfish surrounds it and hides in the hole. The old flare grows back again. Crayfish are very sensitive to water pollution, which is why in the places where they live they talk about eco-lo-gi-che -shoy chi-sto-te vo-do-e-mov.
Dragonfly
Near the river you can see different dragonflies: kra-sot-ku, arrow-ku, lyutka, they live by the river in a hundred-yan-but way (Fig. 18).
Unicellular
All dragons need water, because only there can their faces live. Li-chin-ki does not look like adult dragonflies, only their eyes are the same. Each eye consists of almost 30,000 tiny eyes (Fig. 19).
Both eyes are bulging, thanks to which the dragon can look in all directions at the same time (Fig. 20). All dragons are predators, they hunt in the air, snatching at things in the air.
Li-chin-ka stre-ko-zy, under-ka-ra-u-live up-to-chu, you-br-throws forward the strongly elongated lower lip . Usually the lips are folded and the head is covered like a mask. It sucks water into a large muscular sac inside the body, and then forcefully throws it out. A shot was fired. After a year, and some after 3, you are on the surface, the skin is lying, and a stream emerges from it. It sits for several hours, spreads its wings and flies away.
Who lives in a drop of water? If you look through a microscope, then an amazing world of unusual creatures opens up. Here is an almost transparent lump that keeps changing all the time - this is an amoeba (Fig. 21).
Other creatures wear tiny shoes, that's what they're called. The shoe's body is covered with eyelashes, each one skillfully controls these eyelashes and swims quickly (Fig. 22).
Tru-ba-chi - the most beautiful ob-ta-te drops, blue, green, similar to the flowers of bindweed (Fig. 23) .
The trumpets move unto-rop-li-in and only forward. If something bothers them, then they eat and play sha-ri-ki. Amoebas, tu-fel-ki and trub-ba-chi are one-kle-precise or-ga-niz-we, pi-ta-yut-sya bak-te-ri-ya-mi.
Predators also live in a drop of water. This is di-di-niy (Fig. 24).
Even though he is smaller than the lady, he not only boldly attacks her, but also completely stares at her, once -like a ball.
In fresh water, plants, animals, bacteria live together, all of them are well-suited are connected to life in water and are connected with each other by chains. When plants and living things die, they accumulate at the bottom of the water, under the influence of the tank -riy dissolve and turn into salts, which are dissolved in water and used others live here. Water is a natural community.
Summing up
This year in class you got a new idea about fresh water as a fresh community and knowledge -ko-mi-lis with his obi-ta-te-la-mi.
source of abstract - http://interneturok.ru/ru/school/okruj-mir/3-klass/prirodnye-soobschestva/presnyy-vodoyom-i-ego-obitateli
presentation source - http://prezentacii.com/obschestvoznanie/6813-zhizn-presnogo-vodoema.html
video source:
There are many natural bodies of water: ponds, lakes, seas and oceans. But rivers and streams cannot be called reservoirs - they are water streams. There are many different fish in rivers and reservoirs: crucian carp, catfish, carp (also known as carp), bream, gudgeon, sturgeon, pike, perch, cod and many others.
The appearance and behavior of fish depend on their living conditions.
All predatory fish have large heads with large mouths armed with sharp teeth. Non-predatory fish eat worms, crustaceans, algae, they have a small mouth - they do not need to swallow other fish.
Catfish is a predatory fish that swims near the bottom, looking for food. Its abdomen is flat, its back is convex, its large mouth is surrounded by antennae. His eyes are small. The color is grayish-yellow with spots, matching the color of sand and pebbles at the bottom of the reservoir.
Pike is also a predatory fish, it has a large head, a large mouth and sharp teeth. She spends a lot of time in ambush, standing in one place and waiting for prey. Seeing a fish, it quickly swims out of its hiding place and grabs it. When the pike is near the surface of the water, it catches midges and mosquitoes falling into the river, sometimes even jumping out of the water to do this. Therefore, its mouth is directed upward, its back is flat, its body is flattened.
In winter, in severe frosts, a strong ice roof appears above the heads of the fish - ice. Pisces usually sleep in winter. Crucian carp and tench burrow into the silt at the bottom of reservoirs; minnows and bleaks winter in depressions with a sandy bottom; carp and bream hide in deep holes overgrown with reeds; sturgeons gather in tight heaps at the bottom, where the water does not freeze. After all, what deeper water, the warmer it is. By the end of winter, fish begin to run out of air. Gasping and convulsively opening their round mouths, they rise to the surface, grabbing air bubbles with their lips. To enrich water with oxygen, people make ice holes in ponds, rivers and lakes. Near them on the ice you can often see fishermen engaged in ice fishing.
By spring, all the fish wake up and begin to spawn - spawn. To do this, they find secluded places so that the eggs cannot be eaten by other fish and animals. Over time, fry appear from the eggs, very small, gray, transparent. They are almost invisible in the water, but many of them still die when they get into the mouths of fish. The surviving fry grow and become adult fish.
Some fish do not spawn; they will give birth to live fry. Children can see their birth by watching the fish in the aquarium (guppies, barbs).
Flying fish live in some large bodies of water. Fleeing from predators, they jump out of the water and fly about three to five meters. In the seas and oceans, they can fly through the air up to two hundred meters, while they flap their fins like wings. There are known cases when fish flew onto the decks of passing ships.
In addition to fish, many different animals live in rivers and other bodies of water: snails, collecting food, crawl along the bottom and plants, and hide from enemies in a house - a hard shell; crayfish move not forward, but backward, pushing off with two claws and leaning on their tail. They have dark color, to match the color of the river bottom. People learned to catch them, as crayfish meat is very tasty. If you pick up a crayfish carelessly, it may pinch your hand painfully with its claws. Boiled crayfish take on a bright red color.
Frogs can live in water and on land; jumping on the grass, they catch insects with their tongue. Frogs are very shy: when they hear footsteps, they quickly jump into the water and dive into the depths. When everything calms down, they look out of the water and inspect the shore: if there is no one there, they go out onto land to warm themselves and catch midges.
Also in reservoirs there are leeches, water bugs, small crustaceans of daphnia (fish in aquariums are fed dry daphnia), etc.
Large animals live in the seas and oceans: dolphins, walruses, seals, squids. But the largest animal on earth that lives in water is the whale. Thirty elephants can fit on his back; but there are also small whales - two to three meters long. Whales breathe with their lungs, not their gills. They have an overgrown nostril in their nose, in which air is stored, like in a bag, so they can stay under water for two hours, after which they rise to the surface to take in a new portion fresh air, and then you can see many fountains above the sea. A whale's stomach holds two to three tons of food; whales swim at a speed of fifty kilometers per hour and dive to a depth of three kilometers. They give birth to live cubs that feed on their mother's milk. Whales live up to fifty years. The whale is a valuable animal: whalebone, skin, liver and fat are used in the manufacture of medicines.
Fish story plan
1.Name.
2. Body parts.
3.Behavior.
4.What does it eat?
5. How offspring appear.
6.What's the use?
Sample story about fish
Crucian carp is a non-predatory fish. His body is elongated, flattened laterally; there are pectoral, dorsal and caudal fins; His mouth is small and he breathes through gills. Covered with scales of an inconspicuous gray color, matching the color of the bottom and driftwood. Crucian carp spend whole days looking for food at the bottom of reservoirs, pulling worms out of the sand, catching water bugs, daphnia, and plucking small leaves in thickets of plants. Its enemy is the pike; it watches for prey in cover, so the crucian carp is always on the alert. Thanks to its narrow body, it can instantly wag its tail, bend its entire body and immediately disappear. In winter, he buries himself in the sand and sleeps. By spring it wakes up and swims to its favorite place to spawn.
People eat fried, salted, smoked and boiled fish; fish soup is called "ukha".
Sample dictionary
Nouns: fin, gills, abdomen, scales, fry, caviar, silt, snag, ice hole, bubbles, ambush, crustaceans - daphnia, shelter, shell, claw.
Verbs: wiggle, bend, hide, burrow, throw (spawn), spawn, back away, dwell.
An ecosystem whose natural habitat is water is called an aquatic ecosystem. It is this that determines the uniqueness of a particular ecosystem, species diversity and its sustainability.
The main factors that influence the aquatic ecosystem:
- Water temperature
- Her chemical composition
- Amount of salts in water
- Water clarity
- Oxygen concentration in water
- Availability of nutrients.
The components of an aquatic ecosystem are divided into two types: abiotic (water, light, pressure, temperature, soil composition, water composition) and biotic. Biotics, in turn, is divided into the following subspecies:
Producers are organisms that produce organic matter with the help of sun, water and energy. IN aquatic ecosystems The producers are algae, and in shallow water bodies - coastal plants.
Decomposers are organisms that consume organic matter. These are various types of marine animals, birds, fish, and amphibians.
Main types of aquatic ecosystems
In ecology, aquatic ecosystems are usually divided into freshwater and marine. This division is based on the salinity of the water. If a liter of water contains more than 35% salts, these are marine ecosystems.
Marine areas include oceans, seas, and salt lakes. Freshwater - rivers, lakes, swamps, ponds.
Another classification of aquatic ecosystems is based on such a feature as the conditions of creation. Here we distinguish between natural and artificial. Natural ones were created with the participation of the forces of nature: seas, lakes, rivers, swamps. Artificial aquatic ecosystems are created by humans: artificial ponds, reservoirs, dams, canals, water farms.
Natural aquatic ecosystems
Freshwater ecosystems
Freshwater ecosystems- these are rivers, lakes, swamps, ponds. All of them occupy only 0.8% of the surface of our planet. Although in fresh water bodies inhabited by more than 40% known to science fish, freshwater ecosystems are still significantly inferior in species diversity to marine ones.
The main criterion for distinguishing freshwater bodies of water is the speed of water flow. In this regard, standing and flowing ones are distinguished. Standing swamps include swamps, lakes and ponds. Flowing ones include rivers and streams.
Standing aquatic ecosystems are characterized by a pronounced distribution of biotic organisms depending on the water layer:
IN top layer(littoral) the main component is plankton and coastal thickets of plants. This is the kingdom of insects, larvae, turtles, amphibians, waterfowl, and mammals live here. The top layer of reservoirs is hunting grounds for herons, cranes, flamingos, crocodiles, snakes.
The middle layer of the reservoir is called profundal. He gets a lot less sunlight, and the food is provided by substances that settle in the upper layer of water. Predatory fish live here.
The bottom layer of water is called benthal. The composition of the soil and silt plays a huge role. This is the habitat of bottom fish, larvae, mollusks, and crustaceans.
Marine ecosystems
The biggest marine ecosystem is the World Ocean. It is divided into smaller ones: oceans, seas, salt lakes. All of them occupy over 70% of the surface of our planet and are the most important component of the Earth's hydrosphere.
In marine ecosystems, the main component producing oxygen and nutrients, is a phytoplankton. It forms in the upper layer of water and, under the influence of solar energy, produces nutrients, which then settle into the deeper layers of the reservoir and serve as food for other organisms.
Large marine ecosystems are the oceans. IN open ocean species diversity is low compared to coastal zones. The bulk of living organisms are concentrated at depths of up to 100 meters: this various types fish, shellfish, corals, mammals. IN coastal areas marine ecosystems, species diversity is complemented by numerous species of marine animals, amphibians, and birds.
In the coastal zones of marine ecosystems, smaller ones (by territory) are distinguished: mangrove swamps, shelves, estuaries, lagoons, salt marshes, coral reefs.
Places on the coast where sea water mixed with freshwater (river mouths), called estuaries. Species diversity This is where the maximum is reached.
All marine ecosystems are very resilient, able to resist human intervention and quickly recover from anthropogenic influence.
Artificial aquatic ecosystems
All artificial aquatic ecosystems are created by man to satisfy his own needs. These are various ponds, canals, creeks, and reservoirs. Smaller ones include oceanariums and aquariums.
Artificial aquatic ecosystems are characterized by the following features:
- Small number of plant and animal species
- Strong dependence on human activity
- The instability of an ecosystem, since its viability depends on human influence.
Shows a clear unity of structure and function. A body of water can be simply described as: stream, river, river, puddle, pond, lake, sea. And it’s more difficult – as an ecosystem.
Main components of the ecosystem
I've come to the conclusion
– writes the famous American scientist E. Odum, –
that just as the frog is considered a classic object of study of the animal organism, the pond is an example for initial study ecosystems... Without overload for the novice researcher a large number parts in the pond can be collected, there are four to study main components of the ecosystem.
What are these four components, components? ecological system(both on the scale of a pond and on the scale of the entire biosphere, which can be perceived as the ecosystem of planet Earth)?
- First of all, these are nonliving substances - the main components of the environment, its inorganic and organic components.
- Then producers, mainly terrestrial plants, which are extracted from the inanimate environment under the influence of solar energy various substances and create, produce a mass of living matter.
- Next come all the other living beings who live either by consuming masses of green plants or by devouring other animals.
- And finally, fungi and bacteria, which exist at the expense of dead tissues of animals and plants: they process and decompose these tissues into simple substances, which are again used by plants.
The frog is a frequent inhabitant of the pond Ecosystem
Four components and one cycle, the cycle of substances in nature. From simple substances through plants, animals, fungi and bacteria - again to simple substances.
This mill spins continuously both in the pond and in the ecosystem of the planet as a whole. And the engine is solar energy.
Thus, ecosystem can be considered a system of inanimate and living components in which all four components act, live, and develop.
From this we can conclude that an ecosystem is not a stone, it is alive, its constituent parts are united, connected into one big whole. If any component parts perform poorly, other parts of the whole take on a share of their work. That's why - the ecosystem is very stable, balanced, balanced, in homeostasis, as environmentalists say. Homeostatic mechanism allows the ecosystem not only to regulate equilibrium state system, but also to restore balance if it is disturbed. Until, of course, until the anthropogenic pressure becomes so powerful that no homeostasis can save the stability of the ecosystem.
Pond as an ecosystem
Considering pond as an ecosystem, three important environmental conclusions can be drawn:
- all elements of this reservoir are closely linked and interact, disruption of the action of one of the elements causes disruption of the structure and life of the entire pond;
- the system is in some balance, homeostasis and is capable of restoring this balance, if the intervention only disrupts this balance, and does not destroy the connections themselves, does not cause ecological disaster systems;
- like a living organism, the system lives, it appears, develops, progresses, reaches its peak, then experiences decline, regression and death (example: temporary reservoirs that form when snow melts, during floods and usually dry up and die in the summer).
Assessment of the condition of the reservoir
At assessing the condition of the reservoir should be considered:
- Anthropogenic pressure on any of the system components. Let’s say that intensive recreational fishing is carried out in a closed reservoir, exceeding the permissible level of exploitation. To maintain a fish stock, it is necessary to periodically introduce and introduce juvenile fish into the reservoir. Another example: the density of fish stocking in a reservoir during stocking turned out to be so high that they do not have enough food. It is necessary to bring in food from outside and feed the fish.
- The anthropogenic pressure on the entire system as a whole is so strong that equilibrium is not restored. Example: washing cars, motorcycles or other vehicles(everyone knows about the dangers of a film of petroleum products left on the surface of the water). Or intensive use of the reservoir by owners of motor boats.
- “Age” and stage of development of the reservoir. In particular, you need to look at the condition of the water and the fish in it. It happens that several days pass from the registration of reservoirs to the deployment of an operation to rescue fry from them. So, when counting, you need to see whether the fry will survive these few days, maybe the water is so bad, the fish are suffocating, and the entire reservoir is close to death, that the operation to save the fry cannot be postponed.
The cleanliness of the reservoir is important factor to assess the state of the aquatic ecosystem A reservoir as an ecosystem – its biogeocenosis
A reservoir system can also be called a biogeocenosis - a combination of its living and nonliving parts. From an ecological point of view, we are only interested in the living part of this system. If we move aside the inanimate component of the system, then the next three form a biocenosis. In the biocenosis of a reservoir there is also homeostasis, balance, coordination of all its components, there is development. You can imagine the biocenosis in the form of chess pieces - individual species animals and plants: they all move differently and separately, but they are all interconnected and as a whole form a game, life on the chessboard.
Of all the connections of the biocenosis, it is more important to catch the food chain. This chain always begins with the consumption of solar energy, therefore, its beginning is plants. Let's try to make a food chain. Microscopic planktonic algae are consumed by daphnia crustaceans, they are consumed by small insect larvae, which become food for juvenile fish, and these juveniles, in turn, are eaten by larger fish, the same ones are eaten with appetite by perches, pikes, well, and we catch these fish from the reservoir. good food chain it worked out.
By the way, everything we consume except table salt and water is solar energy “passed” through the food chain. The shorter the chain, the more fully, without loss, this energy reaches us. Therefore, humans or predatory animals on land rarely feed on carnivorous birds and animals - this is an irrational lengthening of the chain. Only in water do we enjoy catching and then eating predators, such as perch and pike perch.
But it happens that the food chain in a reservoir is not so prosperous. For example: algae - daphnia - larvae - fry - ruffs. What about pikes? Pike are left with ruffs, but because of the sharp spines on their fins, their toothy predators are not very fond of them. You can’t get close to the fry, they are in shallow water, the pike are not very accustomed there, but the ruffs just scurry around there. By itself, it is an excellent fish in the ear, but in a reservoir with more valuable fish, it acts as its competitor and turns into a trash, harmful fish. It is clear that this must be taken into account when assessing a reservoir, and then, together with specialists, help valuable fish: organize a kind of “weeding” of the reservoir from weeds.
Relationships between neighboring species in a body of water
In a biocenosis there can be non-stressed and tense relationships between neighboring species in a body of water.
For example, tense eating relationships– This is when species compete over similar food items. Stocking reservoirs with fish that feed on the same food as the old-timer fish in this reservoir will not have any effect. It’s another matter if, during stocking, it is possible to avoid food competition between fish species due to the divergence of their nutritional needs. Then the old-timer fish live successfully, and the newly introduced fish grow well and produce a good catch. IN lately fish farmers try to stock fish not with one species of fish, but with several fish that do not compete in food, such as carp and peled. Introducing silver carp, grass carp and carp into a pond gives brilliant results. Carp collects food near the bottom, silver carp feeds on plankton and phytoplankton (flowering water), and grass carp eats higher aquatic vegetation.
Reservoir assessment
At reservoir assessment it should be classified as natural or as a reservoir. The first include rivers and lakes. What about the pond? It is, of course, an artificial reservoir formed by a dam, but not every pond can be considered a reservoir. May be, crucial what are its dimensions? No, it is not the size, not the volume of water that is important. The main feature of a reservoir - both a large and a small pond - is the ability to regulate the flow of water from the reservoir and its level.
Reservoir - artificial reservoir Fish ponds
For fish farming, the most convenient reservoirs are those from which the water can be completely drained. Usually this fish ponds. After draining the water, you can refill the reservoir and stock it with only those species of fish that produce greatest effect when growing. Discharge reservoirs – the best remedy fight against fish competition, better “weeding” of the reservoir from weed fish.
Reservoir productivity can be increased in other ways, for example, by introducing fish food into the reservoir or introducing food organisms, which themselves will quickly multiply to the delight of the fish and the fish farmer. The productivity of reservoirs is also facilitated by the removal of enemies of commercial fish from them. The enemies of fish can be vertebrates - birds, animals, but they can also be invertebrates. Many insect larvae eat fish fry, and in general, all invertebrates in a body of water destroy more food than all the fish in that body of water taken together.
It is also necessary to take into account the assessment of the shores, shallow waters and bays, the nature and accumulation of aquatic vegetation, water temperature in different places and warming up at different depths...
Therefore, a reservoir is a very complex natural object.
Biocenosis of the reservoir
In other words, a body of water is a living organism, a complex of nonliving and living components that form a biocenosis, and a biocenosis has youth, maturity, and old age. If biocenosis of the reservoir Today it promotes spawning and the development of valuable fish, then our task is to preserve this age of the reservoir longer, to try to delay its aging. If the biocenosis of a reservoir tends towards aging, it is necessary to carefully establish the causes of this phenomenon and, if possible, try to remove a number of these causes and rejuvenate the reservoir.
Reservoir survey
To determine what condition it is in water, we need to examine him.
- First of all, the type of reservoir - river, river, lake, lake;
- size of the reservoir;
- movement of water – flowing, semi-flowing, standing.
- Along with speed, it takes into account smoothness of flow: with a large slope river water can rush at a higher speed, but in northern rivers this is usually a smooth fast current, and in the south in mountainous areas the speed of the river is often higher, the water forms breakers and whirlpools among the stones. In closed lakes, the mobility of water depends on the nature of the shores: with open shores, the wind moves freely, forming waves and mixing water mass, in forest lakes the water surface rarely wrinkles from the wind and the water is poorly mixed, the lower layers can be much colder and may be poor in oxygen. This means that the characteristics of a reservoir include a description of its shores. The dimensions (length, width) and depth of the reservoir are determined.
- Information about greatest depth in the characteristics of the reservoir should be combined with information about smaller bays and well-warmed shallows. Determine water transparency, color, taste.
- Water samples for acidity delivered to the laboratory for analysis. Using these samples, it is possible to determine the sources of water pollution and send signals to the sanitary and epidemiological station.
- It is not always easy to prevent water pollution. Greater role in compliance clean water play origins rivers and streams feeding reservoirs. Sometimes these springs are polluted, the banks are trampled, and garbage gets into the water. It is necessary to clean the springs, install benches near them, and build bridges from which you can draw water without destroying the banks. The bottom of the springs must be cleared of debris, silt, and snags. All discovered springs are numbered, entered into the characteristics of the main reservoir, if possible, their location is plotted on a map, topographical diagram. There are general requirements to the composition in reservoirs. When assessing the oxygen content in water in the field, if the water is not very polluted, you can proceed from average values.
Above 30°C, water warms up only in shallow waters, so fish warm water, poor in oxygen, they do not like it and retreat to depth. Widespread water heating above 25°C practically occurs only in small, isolated reservoirs, and fish from such reservoirs need to be relocated most urgently.
Finally, when assessing a body of water, data about the fish inhabiting it and other aquatic inhabitants, including the enemies of the fish, are entered into its passport.
Information about aquatic plants
Entered into the passport and information about aquatic plants.
Aquatic plants - important element any body of water Algae and mosses- primordial aquatic plants. Algae and moss fontinalis completely immersed in water sphagnum moss has aquatic ecological races that grow under water (usually in forest lakes); more often, sphagnum grows in swampy lowlands that are temporarily flooded. These thickets are useful for the fry, although long threads of green algae sometimes grow so large that the fry become entangled in them and die. However, in a healthy mature reservoir, these plants do not grow in a continuous mass.
The situation is different with higher aquatic vegetation - flowering plants. These plants earlier, in the course of evolution, left the water, moved to land, and then individual representatives land plants went back into the water. But one thing is typical for all of them - almost all of them have not completely lost touch with former homeland – air environment. Duckweed floats on the surface of the water, egg capsules and water lilies bring leaves and flowers to the surface (do not bloom if the leaves have not reached the surface), elodea and pinnate flowers rise above the water, reeds and sedges They grow above the water, only the roots, the lower part of the stem is in the water.
If we look closely at these plants, we will see that in a reservoir they are usually located in species communities: here is a sandbank with a forest of Elodea, next to it is a bay with hornwort, at a distance there are thickets of pondweed, green plates of water lilies float deeper. Hornwort- the only higher plant that has lost contact with air: it even blooms in water. It has no roots, it is heavy, immersed in water. If thickets of hornwort densely fill the shallows, the tops of the stems reaching the surface of the water, it is necessary to thin out these thickets: fish are cramped in them, and predatory insects develop there successfully and watch for fry. Hornwort thickets are easily removed by hand or with a rake; they are dragged to the shore, away from the water.
It’s bad when Elodea grows rapidly; its thickets also interfere with young fish and create unnecessary stress for them. danger zone. Removing elodea is just as easy; its anchor roots loosely hold the plant to the ground.
Near the surface there is a hornwort-like floating plant with small dissected leaves, from light green to bright purple in summer. Fluffy stems float horizontally, branch abundantly, flowers are above the water. If you look closely at these stems, you can see bubbles among the leaves. This is a carnivorous bladderwort plant. Small animals can enter the bubbles, but there is no way back out of the bubbles. The crustacean or fry of the fish gets stuck, then the juices of the plant dissolve the prey, and the walls of the bubble absorb the nutrient solution. It is clear that this predator should not have a place in spawning reservoirs, on shallows where natural spawning of fish occurs. Pemphigus not only can it encroach on fish fry - in their most difficult and responsible stage of life, when they are weak and helpless immediately after hatching from eggs - it also acts as a food competitor for the fry, absorbing countless quantities of nutritious rotifers and crustaceans - the primary food of fish babies .
Floating on the surface duckweed of all types and the near-surface type - duckweed trilobed (its leaves do not touch the air) are not scary until they begin to violently take over all the creeks, and then the entire reservoir. Overgrowing of the entire surface with duckweed is a sign of aging of the reservoir. Such duckweed “ice” must be removed. Duckweed is caught from a reservoir with a bag placed on a square frame and a tight net. Duckweed is a good vitamin supplement for pig and poultry feed, so it is useful to dry it, collect it and use it on farms. Finally, cattail, sedge, reed– tough coastal vegetation. If there is a little of it along the banks, it does not interfere, but if these semi-aquatic grasses grow, they interfere with fish farming and can absorb the entire shallow body of water, turning it into. The growth of these grasses over the area of the reservoir is a sign of the aging of the reservoir. Therefore, these plants must be actively mowed. Here are the basic information about the reservoir as an ecosystem.
