Features and distribution of life in the seas and oceans. Features and distribution of life in the seas and oceans Table distribution of life in the ocean

1. What animals and plants you know live in the ocean?

Plankton, crabs, whales, dolphins, killer whales, sharks, fish, algae.

2. What is the difference between the living conditions of organisms in the ocean from their living conditions on land?

Significant differences in living conditions on land and in water are: the method of oxygen consumption; features of adaptation to gravitational influence; features of photosynthesis in plant organisms; features of methods of movement in space; features of breeding methods, etc. Some organisms that previously lived on land have returned to the water, for example, whales and dolphins, sea turtles. Some feel equally well, both in water and on land, for example, amphibians.

3. How does a person use marine organisms?

Catching and eating.

4. How is the world water cycle carried out?

The water cycle in nature is the process of cyclic movement of water in the biosphere. It consists of water evaporation, vapor transport by air currents, their condensation, precipitation and water transport in rivers and other bodies of water. Most of the water evaporates from the surface of the oceans.

5. Why is the movement of air masses?

Due to uneven heating of the Earth.

Questions and Tasks

1. What is the peculiarity of the spread of life in the ocean?

Life in the oceans is widespread, but the species composition and density of plants and animals in the waters of the ocean are extremely diverse and uneven.

2. What determines the distribution of organisms in the surface layer of water?

The distribution of organisms in the surface layer of water depends on the amount of oxygen in the water and light. In warm waters there is little oxygen and little life, especially in the depths. In the north and in temperate latitudes, there is a lot of oxygen in the water, due to seasonal mixing of water, when heavy cold water with oxygen drops down, and warm water rises up, where it cools and in general it is a mix. In cool water there are more living organisms, due to the abundance of oxygen. And its greatest concentration falls to a depth of 200 m, sunlight can penetrate to such a depth.

3. What parts of the ocean are particularly rich in life?

In its upper layers, somewhere up to 100 m, sufficient illumination and a lot of oxygen dissolved in water are preserved. This is the most favorable layer for life in the ocean. Plankton lives here and there are plants. Deeper than 1 kilometer there is no light. It's completely dark here. Only bacteria and animals can live here. The number of living organisms here is much smaller than in the layers lying above. Life in the ocean changes not only with depth, but also depends on latitude, that is, on climate. In the region of the poles of the Earth there are few living organisms, since there the water is too cold. Plankton appears here only in the summer. Since it serves as food for fish and animals, they also swim here only for the time when the ice disappears. In temperate latitudes, not only the temperature is higher, but also a lot of oxygen is dissolved in water. Therefore, there are many living organisms. In tropical zones, the temperature is very favorable for life, but high salinity and a small amount of oxygen in the water do not allow plankton to multiply greatly. As a consequence of this, there are not so many fish here. However, in tropical waters there is much greater diversity of living organisms. There are many corals in the equatorial belt. Many living organisms live near the mouths of large rivers, as nutrients are brought from the rivers. Regardless of latitude and climate, there is a pattern that life is greater in shallow waters, shelves of the seas and oceans than in areas of the ocean remote from them.

4. How is the exchange of heat and moisture between the ocean and land?

The ocean heats up slowly, but retains heat longer. He transfers this heat to the atmosphere during the evaporation process. Moisture falling from the clouds is transported to land through air circulation. Further, through underground and surface runoff returns to the ocean. That is, the water cycle in nature.

5. What is the difference between the air masses formed over land and the ocean?

The air masses formed over land differ from the air masses formed over the ocean, greater humidity and slight temperature differences between the seasons.

6. Why does ocean life require protection?

Because it depends on the conservation of all species living in the oceans of organisms. The ocean will empty, we will disappear. Ocean algae give 80% of the oxygen to the atmosphere, not forests at all. Ocean - light planets, pantry of water and food, climate regulator.

7. Give examples of marine organisms belonging to each of the three groups that differ in lifestyle.

Nectons are actively floating. These include more than 20,000 species of fish, squid, cetaceans, pinnipeds, aquatic snakes, turtles, penguins, etc. Plankton - passively swimming. These include bacteria, protozoa, some coelenterates, mollusks, crustaceans, eggs and larvae of fish, larvae of various invertebrate animals and other benthos living on the bottom. These include starfish, oysters, flounders, mussels, methiola, mission, sea cucumber, ophiura, anemones, oysters, crabs, etc.

8. What professions do people need to master in order to work at sea?

Sailor, oceanologist, scuba diver, diver.

The oceans cover more than 70% of the Earth’s surface. It contains about 1.35 billion cubic kilometers of water, which is about 97% of all water on the planet. The ocean supports all life on the planet, and also makes it blue when viewed from space. Earth is the only planet in our solar system that is known to contain liquid water.

Although the ocean is one continuous body of water, oceanographers have divided it into four main areas: Pacific, Atlantic, Indian and Arctic. The Atlantic, Indian and Pacific Oceans unite in the icy waters around Antarctica. Some experts identify this area as the fifth ocean, most often called the South.

To understand the life of the oceans, you must first find out its definition. The phrase “marine life” encompasses all organisms living in salt water, which include a wide variety of plants, animals, and microorganisms such as bacteria and.

There is a huge variety of marine species that range from tiny unicellular organisms to giant blue whales. As scientists discover new species, learn more about the genetic makeup of organisms and study fossil specimens, they decide how to group oceanic flora and fauna. The following is a list of the main types or taxonomic groups of living organisms in the oceans:

(Annelida);
(Arthropoda);
(Chordata);
(Cnidaria);
Grebneviki ( Ctenophora);
(Echinodermata);
(Mollusca)
(Porifera).

There are also several types of marine plants. The most common are Chlorophyta, or green algae, and Rhodophyta, or red algae.

Adaptation of marine life

From the point of view of a terrestrial animal like us, the ocean can be a harsh environment. However, marine life is adapted for life in the ocean. Features that contribute to the prosperity of organisms in the marine environment include the ability to regulate salt intake, organs to produce oxygen (such as fish gills), withstand high water pressures, and adaptation to lack of light. Tidal animals and plants deal with extreme temperatures, sunlight, wind, and waves.

There are hundreds of thousands of species of marine life, from tiny zooplankton to giant whales. The classification of marine organisms is very variable. Each is adapted to its specific habitat. All oceanic organisms are forced to interact with several factors that do not pose problems for life on land:

Regulating salt intake;
Oxygen production;
Adaptation to water pressure;
Waves and changes in water temperature;
Getting enough light.

Below we will look at some ways of survival of marine life in this environment, which is very different from ours.

Salt regulation

Fish can drink salt water and remove excess salt through their gills. Seabirds also drink sea water, and excess salt is removed through the “salt glands” into the nasal cavity, and then shaken out by the bird. Whales do not drink salt water, but receive the necessary moisture from their organisms, which they feed on.

Oxygen

Fish and other organisms that live underwater can receive oxygen from water either through their gills or through their skin.

Marine mammals are forced to float to the surface in order to breathe, so whales have breathing holes on top of their heads, allowing them to breathe air from the atmosphere, keeping most of their body under water.

Whales are able to remain under water without breathing for an hour or more, since they use their lungs very effectively, filling up to 90% of the lung volume with each breath, and also store an unusually large amount of oxygen in the blood and muscles when immersed.

Temperature

Many animals of the ocean are cold-blooded (ectothermal), and their internal body temperature is the same as their environment. The exception is warm-blooded (endothermic) marine mammals, which must maintain a constant temperature of their body regardless of the temperature of the water. They have a subcutaneous insulating layer consisting of fat and connective tissue. This layer of subcutaneous fat allows them to maintain their internal body temperature about the same as that of terrestrial congeners, even in the cold ocean. The insulating layer of bowhead whale can reach more than 50 cm in thickness.

Water pressure

In the oceans, water pressure increases by 15 pounds per square inch every 10 meters. While some sea creatures rarely change water depths, far-swimming animals such as whales, sea turtles and seals travel from shallow water to great depths in a few days. How do they deal with pressure?

It is believed that the sperm whale can plunge more than 2.5 km below the surface of the ocean. One of the adaptations is that the lungs and chest tighten when diving to great depths.

A leathery sea turtle can dive more than 900 meters. Foldable lungs and a flexible sink help them withstand high water pressures.

Wind and waves

Tidal animals do not need to adapt to high water pressures, but must withstand strong wind and wave pressure. Many invertebrates and plants in this have the ability to cling to rocks or other substrates, and also have hard protective shells.

While large pelagic species, such as whales and sharks, are not affected by the storm, their prey can move. For example, whales prey on copepods, which can be scattered in different remote areas during strong winds and waves.

sunlight

Organisms that need light, such as tropical coral reefs and their associated algae, are found in shallow, clear waters that easily transmit sunlight.

Since underwater visibility and light levels can vary, whales do not rely on vision to find food. Instead, they find prey using echolocation and hearing.

In the depths of the ocean abyss, some fish lost their eyes or pigmentation, because they simply are not needed. Other organisms are bioluminescent, using luminiferous or their own light producing organs to attract prey.

Distribution of life of the seas and oceans

From the coastline to the deepest seabed, the ocean is teeming with life. Hundreds of thousands of marine species range from microscopic algae to the blue whale that has ever lived on Earth.

The ocean has five main zones of life, each with unique adaptations of organisms to its specific marine.

Euphotic zone

The euphotic zone is the sunlit upper layer of the ocean, up to about 200 meters in depth. The euphotic zone is also known as the photic zone and can be present both in lakes with seas and in the ocean.

Sunlight in the photic zone allows the process of photosynthesis. - This is the process by which some organisms convert solar energy and carbon dioxide from the atmosphere into nutrients (proteins, fats, carbohydrates, etc.), and oxygen. In the ocean, photosynthesis occurs through plants and algae. Seaweed is similar to land plants: they have roots, stems and leaves.

Phytoplankton - microscopic organisms that include plants, algae and bacteria, also live in the euphotic zone. Billions of microorganisms form huge green or blue spots in the ocean, which are the foundation of oceans and seas. Due to photosynthesis, phytoplankton is responsible for the production of almost half of the oxygen released into the Earth’s atmosphere. Small animals such as krill (a type of shrimp), fish, and microorganisms called zooplankton all feed on phytoplankton. In turn, these animals are eaten by whales, large fish, seabirds and people.

Mesopelagic zone

The next zone, extending to a depth of about 1000 meters, is called the mesopelagic zone. This zone is also known as the twilight zone, since the light within it is very dim. The lack of sunlight means that there are virtually no plants in the mesopelagic zone, but large fish and whales dive there to hunt. Fish in this area are small and luminous.

Bathipelagic zone

Sometimes animals from the mesopelagic zone (such as sperm whales and squid) dive into the bathipelagic zone, which reaches a depth of about 4000 meters. The bathypelagic zone is also known as the midnight zone because light does not reach it.

Animals that live in the bathipelagic zone are small, but they often have huge mouths, sharp teeth and expanding stomachs that allow them to eat any food that enters the mouth. Most of this food comes from the remains of plants and animals descending from the upper pelagic zones. Many bathypelagic animals have no eyes, because they are not needed in the dark. Because the pressure is so great that it’s hard to find nutrients. Fish in the bathipelagic zone move slowly and have strong gills to extract oxygen from the water.

Abyssopelagic zone

Water at the bottom of the ocean, in the abyssopelagic zone, is very salty and cold (2 degrees Celsius or 35 degrees Fahrenheit). At a depth of up to 6,000 meters, the pressure is very strong - 11,000 pounds per square inch. This makes life impossible for most animals. To cope with the harsh conditions of the ecosystem, the fauna of this zone has developed bizarre adaptive features.

Many animals in this zone, including squid and fish, are bioluminescent, that is, they produce light through chemical reactions in their bodies. For example, anglerfish has a bright appendage located in front of its huge toothy mouth. When the light lures a small fish, the anglerfish simply clicks its jaws to eat its prey.

Ultra abyssal

The deepest zone of the ocean found in faults and canyons is called ultra-abyssal. Few organisms live here, for example, isopods - a type of crustacean akin to crab and shrimp.

Such as sponges and sea cucumbers, thrive in the abyssopelagy and ultra-abyssal zones. Like many starfish and jellyfish, these animals are almost completely dependent on the settling remains of dead plants and animals called sea detritus.

However, not all bottom dwellers depend on marine detritus. In 1977, oceanographers discovered a community of creatures at the bottom of the ocean that feed on bacteria around holes called hydrothermal vents. These vents divert hot water enriched with minerals from the bowels of the Earth. Minerals feed unique bacteria, which in turn feed animals such as crabs, shellfish, and tubular worms.

Threats to marine life

Despite the relatively small idea of the ocean and its inhabitants, human activity has done tremendous damage to this fragile ecosystem. We constantly see on television and in newspapers that the next sea view is endangered. The problem may seem depressing, but there is hope and many things that each of us can do to save the ocean.

The threats presented below do not have any specific order, since in some regions they are more relevant than in others, and some inhabitants of the oceans face numerous threats:

Ocean acidification - if you have ever had an aquarium, you know that the correct pH of water is an important part of maintaining the health of your fish.
Changing of the climate - we constantly hear about global warming, and not in vain - it negatively affects both marine and terrestrial life.
Overfishing is a worldwide problem that has depleted many important commercial fish species.
Poaching and illegal trade - Despite laws passed to protect marine life, illegal fishing has flourished to this day.
Nets - marine species from small invertebrates to large whales can become entangled and die in abandoned fishing nets.
Garbage and pollution - Various animals can become entangled in garbage, as well as in nets, and oil spills cause great damage to most marine life.
Habitat loss - As the world's population grows, the anthropogenic pressure on the coastline, wetlands, algae forests, mangroves, beaches, rocky shores and coral reefs, which are home to thousands of species, increases.
Invasive species - species introduced into the new ecosystem can cause serious harm to their native inhabitants, because due to the lack of natural predators they can experience a population explosion.
Sea vessels - ships can cause fatal damage to large marine mammals, and also create a lot of noise, carry invasive species, destroy coral reefs with anchors, and lead to the release of chemicals into the ocean and atmosphere.
Ocean noise - the ocean has a lot of natural noise that is an integral part of this ecosystem, but artificial noise can disrupt the rhythm of life of many marine inhabitants.

Remember

How does the temperature and salinity of the surface waters of the ocean change depending on latitude? What determines the amount of oxygen dissolved in water? What is a shelf?

The spread of organisms depending on depth. With depth, the amount of sunlight dissolved in oxygen water decreases, and pressure builds up. The upper layer of water to a depth of 100 m is well lit and contains a lot of oxygen. Therefore, in this layer are almost all plants and the entire plankton of the ocean. Up to a depth of 1000 m, the middle layer of water extends with twilight lighting. Even deeper - to the very bottom - is the lower layer, which does not receive light at all. There are no plants in this layer; here is the kingdom of animals and bacteria. The saturation of organisms here is several thousand times less than in the upper layer. Due to the complete darkness, deep-sea animals have developed special devices - luminescence organs. They are used to attract prey, disguise or mislead the victim or hunter.

The inhabitants of the depths experience the pressure of water. The greater the depth, the higher the pressure. People, for example, cannot be deep without special equipment. In deep-sea animals, the pressure of water is balanced by the pressure of the fluid inside their organisms. Life in the water column with different pressures is often reflected in the shape of the body of fish (Fig. 164).

The spread of organisms depending on the climate. Due to climate change from the equator to the poles in the same direction, the properties of water, and therefore the features of the organic world, are changing.

In the Arctic and Antarctic zones, life is very poor. There are few species of living organisms, as well as individuals themselves. Plankton develops only in a short summer period and only in places that are free of ice. Following plankton, fish and their eating walruses and seals appear.

Fig. 164. Fish from different layers of the water column

Herrings living in the upper layers of the ocean have a laterally compressed body. The sharks and tuna that live in depth, the body and from top to bottom and laterally compressed almost the same. At bottom slopes and flounder, the body is flat, squeezed from top to bottom.

In temperate zones, the water temperature is above 0 ° C all year round. The abundance of oxygen dissolved in water leads to the rapid development of life. In temperate zones, the diversity of organisms is not very great, but there are many individuals of each species. The temperate latitudes are rich in fish, and here it is actively fished (herring, hake, cod, saury, salmon).

In tropical belts all year high water temperature and high salinity. There is little dissolved oxygen and nutrients in the water. Because of this, less than in the temperate zones, plankton, and therefore fish. However, in hot zones there is a huge variety of thermophilic fish and bottom organisms (corals, mollusks, echinoderms, crustaceans).

In the equatorial zone, the water temperature is high all year. The rapid development of life is observed near the mouths of large rivers that carry nutrients into the ocean. At the bottom of the oceans are many coral buildings. In equatorial waters, sea turtles, mollusks, tuna, sardines, and mackerel are caught.

The spread of organisms depending on the remoteness of the coast. The most favorable conditions for both plants and animals are in shallow water zones. These are the shelves of the seas and oceans. In their shallow waters there is a lot of light, heat, nutrients. Thanks to active mixing, water is enriched with oxygen. Towards the open ocean, the saturation of life decreases hundreds of times.

A rich world of benthic animals has been found in areas of the bottom of the oceans, where there are outlets of hot groundwater and gases. Large mollusks live here, vestimentifers are outlandish creatures similar to large (up to 1 m long) worms. These and other animals feed on special bacteria that create organic matter not through photosynthesis, but through chemical reactions.

Shelf is about 9% of the total ocean. However, 99% of all bottom organisms are concentrated here and more than 90% of all marine fish are caught.

Questions and Tasks

What causes the diversity and number of organisms in different parts of the ocean?
How does the organic world of the oceans change with depth?
Why are there more living organisms in the coastal parts than in the open ocean?
In which climatic zone are most marine organisms and why?

Ocean living conditions. Ocean water contains all the substances necessary for the life of organisms. Ocean life is all-pervasive. It exists at the bottom of the Mariana Trench, at a depth of 11 thousand meters, and even where a new crust is formed, where hot magma comes from the depths of the Earth through faults, where there are high temperatures and huge pressure.

Living conditions in the ocean from the pole to the equator, from the surface to the maximum depths are very different. Therefore, the diversity of life in the ocean is unusually great. It contains bacteria, unicellular plants that are not visible to the naked eye, and algae up to 80 m long, microscopic animals and huge blue whales. By the diversity of plant and animal species, the ocean is quite comparable with land.

The ocean is full of hidden life and secrets that amaze the imagination. Many of them have not been disclosed so far. In the study of the depths of the sea, organisms unknown to science are still found.

According to most scientists, all life on our Planet came out of the ocean, so it is called the "cradle" of life on Earth. The development of life in it led to a change in the properties of water (salinity, gas content). For example, the spread of green plants in the ocean that can release oxygen has led to an increase in the amount of oxygen in the water. From the water, it stood out in the atmosphere, changed its composition. An increase in the amount of oxygen in the atmosphere made it possible for the land to be populated by organisms coming from the ocean.

The distribution of organisms in the water column. The living conditions of organisms in the water column and in the bottom areas are different. All marine organisms according to their living conditions are divided into three groups. The first includes organisms that live on the surface and in the water column and do not have active means of transportation. The second group consists of organisms that actively move in the water column, and the third - organisms that live at the bottom. Organisms that are in suspension in water and are not able to withstand the passage of currents, called plankton (in Greek - wandering). Plankton consists of algae and tiny animals. Plant plankton forms real "pasture" on which animal plankton develops.

Many bacteria live in the water column, spreading to the very depths. Thanks to the activity of bacteria, dead organisms decompose, and the substances necessary for feeding living organisms again enter the biological cycle.

Actively moving organisms live everywhere in the ocean. These are fish, marine mammals (dolphins, whales, seals, etc.), squid, sea snakes, turtles, etc.

Life in the water column is unevenly distributed. Most living organisms live in the surface of a hundred-meter layer illuminated by sunlight. In this layer, the distribution of life depends on geographical latitude. Due to low temperatures and a long polar night, polar waters are poor in plankton. A large amount of plankton develops in summer in the waters of temperate latitudes of both hemispheres. Here currents, strong winds contribute to the mixing and rising of deep waters, their enrichment with nutrients and oxygen. Temperate latitudes (40 - 60 °) are the most fishy areas of the ocean.

In tropical latitudes, the number of living organisms decreases, since water on the surface has an elevated temperature, salinity, and poorly mixes with deep water masses. In equatorial latitudes, the number of organisms is increasing.

The distribution of life at the bottom of the ocean. The organisms of the bottom layers and the bottom itself include algae, corals, crustaceans, worms, mollusks, starfish, etc. Of the fish, flounder, halibut live here; octopuses live. Well lit and warmed up coastal areas are especially rich in life. Many nutrients come from land from the erosion of coasts by waves and currents. Over 99% of plants and animals living on the seabed are concentrated here. Algae, for example, form huge underwater meadows.

In the warm tropical waters at the bottom, marine invertebrates live - corals that form reefs and islands.

The biological wealth of the ocean. The ocean has long been the breadwinner of man. It hunts mammals, fish, invertebrates, collect algae, catch krill - small sea crustaceans. Marine organisms are not only a source of food, but also medicines, raw materials for the chemical industry.

The oceans of the world possess large, but still limited biological wealth, and humanity faces the important task of their rational use, protection and multiplication.

End of work -

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Atmosphere. Composition, structure and boundaries of the atmosphere

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Life on our planet arose a very long time ago. The main role in this was played by water. It is with its appearance on Earth that the appearance of the first organisms is associated. Therefore, the oldest living organisms on the planet are marine organisms. They appeared more than 3.5 billion years ago, while land organisms were able to cross over to it only after 3 billion years.

What organisms now live in the depths of the sea and why their distribution depends on?

No matter how strange it sounds, the living conditions of organisms in the ocean are much more favorable than the conditions that exist for the organisms that inhabit land. So, a blue whale weighing 150 tons is 20-30 times heavier than an elephant, but in ocean water it is much easier for him to move than an elephant on land. This is because a buoyant force presses the animal in the water, so a whale spends much less energy on its movement than an elephant on land.

Another advantage of the life of organisms in the oceans is the fact that they are subject to much lower temperature extremes than other organisms. This is due to the fact that water heats up and cools more slowly than land, therefore, temperature fluctuations in the aquatic environment are less.

The existence of life in the waters of the ocean is possible only due to the presence of oxygen in the water. He comes here from algae, which, due to the fact that they can carry out photosynthesis, convert carbon dioxide into oxygen. And since there are more algae in the surface layers of the water, there will be many marine organisms here. However, there are also such organisms that live at very great depths, because thanks to sea currents, oxygen also enters this part of the ocean.

All marine organisms can be divided into 3 groups: plankton - this group consists of marine organisms that are not able to move independently, but are carried by streams of water. These include microscopic algae, crustaceans, jellyfish. Plankton serves as food for fish and other aquatic animals.

The next group includes free-floating organisms or nekton. This group includes fish, whales, turtles, penguins other.

The last group consists of organisms living on the bottom of the ocean - benthos. it algae, crabs, worms, lobster, sea urchins.

What determines the spread of organisms in the oceans?

The main factor here is amount of light, heat and oxygen. AT coastal areas where there is enough sunlight and heat, whole columns grow seaweed inhabited by many fish, shellfish, crab . AT bottom areas marine organisms are much smaller.

Previously, it was even believed that no marine organism could live deeper than 6 km. However, it is not. In the most the deepest parts of the oceans can be found bacteria, some crustaceans and even fish . The water contained in the bodies of these organisms is compressed very little, so the external pressure is easily balanced by their internal pressure. They feed mainly on the remains of other organisms that come here from the upper layers, or by eating each other. Some species even had special adaptations for life in the dark oceanic depths - luminous lanterns on their heads.

Scientists have calculated that in their history of living organisms in 2 million years passed through all the water of the hydrosphere, in 2 thousand years all the air in the atmosphere, and in 300 years all carbon dioxide. This fact proves that living organisms inhabiting our planet have a significant impact on all its shells.

How does this happen?

The plants that inhabited the Earth’s surface for a very long time contributed to the formation of its gas shell - the atmosphere. It is thanks to their ability to carry out photosynthesis, i.e. convert inorganic substances into organic, while releasing oxygen and absorbing carbon dioxide, the necessary conditions for the development of other organisms gradually formed on the earth's surface. And also plants absorb dust from the atmosphere, enrich our air shell with water vapor. Therefore, to preserve their existence on our planet is one of the main tasks of man.

Scientists have determined that over the past 170 million years, the composition of sea water has not changed. But how can this be explained, because water constantly evaporates from the surface of the ocean and the salts contained in it must accumulate? This question is easy to answer by considering the influence of living organisms on the water shell of the Earth - the hydrosphere. To build their skeletons, shells, and shells, marine organisms need calcium, which they absorb from sea water. When perishing, the remains of organisms sink to the bottom, accumulate, gradually turning into sedimentary rocks. This constantly occurring process in the oceanic strata contributes to an almost constant composition of sea waters.

The impact of living organisms on the lithosphere is manifested in the fact that when they die, their remnants in the earth's crust gradually turn into sedimentary rocks. Such rocks include chalk, marl, rock salt and so on.

Living organisms can not only form rocks, but also destroy them, i.e. contribute to weathering. This is due to the acids secreted by plants, or due to the effect on the rocks of their root system. Gradually, solid rocks turn into friable, becoming the basis for soil formation.

The soil - This is a special formation that cannot be attributed only to organic or inorganic bodies. The soil Is the top layer of the earth’s crust, which has fertility.

It consists of both rock particles and the remains of living organisms that form humus (humus). In addition, there is always air, water and a huge number of microorganisms in the soil: in 1 g of soil there are more of them than people living on our planet.

But the presence of humus in the soil determines its main property - fertility.

Fertility - the ability of the soil to provide plants with nutrients. The more humus in the soil, the more fertile it is.

The most fertile soils in the world are chernozems. The thickness of the humus in them reaches 1 meter. It has a black color, which determined the name of these soils. Black Earth Distribution Zone are steppes.

In most of the territory of Russia there are podzolic and sod-podzolic soils. This is the so-called zonal soils of taiga and mixed forests. The humus layer in them is not very large, so these soils are not as favorable for growing crops as chernozems. But on the other hand, forest grows very well on these soils.

Unfortunately, a person very often destroys the soil through his activity, but in order to form at least 1 centimeter of it, it takes 100-150 years. Therefore, the soil must be protected, and in order to increase their fertility, it is necessary to make fertilizers in them and properly process.

To summarize.

The living conditions of organisms in the ocean are much more favorable than on land.

All marine organisms are divided into 3 groups: plankton, nekton and benthos.

The main factor determining the distribution of marine organisms is amount of light, heat and oxygen.

Living organisms affect all shells of the Earth: atmosphere, hydrosphere and lithosphere. Changing under their influence, the rocks that make up the earth's crust gradually become loose, forming the soil.

The soil - This is the upper layer of the earth's crust, which has fertility. Fertility - Its main property, which helps to provide plants with nutrients.