“Features of life in the ocean. Spreading life in the ocean

The world's oceans occupy almost three quarters of the Earth's surface. Surprisingly, underwater world less studied than space, and no one has ever dived to a depth of more than 6 kilometers. This is due to enormous technical difficulties associated with high water pressure, lack of light and oxygen in the deep layers of the ocean. Nevertheless, there is life in the ocean and it is quite diverse.

Scientists claim that more than 200,000 species of organisms live in the surface, middle and deep layers of ocean waters. Life in the ocean is unevenly distributed, the coastal places with a depth of up to 200 meters are most saturated with plants and animals, these places are well illuminated and warmed up by sunlight, which is necessary for algae to exist. Away from the coastal zone, algae are rare because the sun's rays hardly penetrate the large layer of water. Plankton dominate here - very small plants and animals that are not able to withstand currents that carry them over long distances.

Most of these organisms (planktons) can only be seen under a microscope. Plankton is divided into phytoplankton and zooplankton. Phytoplankton are various types of algae, zooplankton are small crustaceans, as well as unicellular animals. In the life of the ocean, plankton is the main food of most of its inhabitants, for this reason the areas are rich in plankton, and rich in fish. Baleen whales can also be found here.

Life in the ocean also exists at its bottom: benthos lives here - these are plant and animal organisms that live on the soil and in the soil of the sea and ocean floor... Benthos includes: molluscs, red and brown algae, crustaceans and other organisms. Among them, an important commercial value have lobster, shrimp, oysters, crabs, scallops. Benthos is an excellent food base for walruses and some fish species.

In addition to plankton and benthos, such marine mammals like dolphins, whales, seals, walruses, sea snakes, squids, turtles and many others. Life in the ocean has always been food for humans as well. In the ocean, fish and mammals are fished, algae are collected in it, and substances that are raw materials for medicines are extracted.

Life in the ocean is so rich that it seemed inexhaustible to people. Large ships different countries went to hunt for whales and fish. The largest whales are blue whales, their weight can reach 150 tons, as a result of the predatory fishing of people, blue whales are endangered. Therefore, in 1987, the USSR stopped whaling. The number of fish in the ocean has also significantly decreased. The problems of the oceans should be the concern of not only one state, but the entire globe. His future depends on how rationally a person will solve them.

OOO The educational center

"PROFESSIONAL"

Discipline abstract:

« Physical geography of continents and oceans and teaching methods with ICT»

On this topic:

“Life in the World Ocean. Distribution of living organisms in the ocean "

Executor:

Baklanova Lyudmila Nikolaevna

Moscow 2018

P.

Introduction

Spreading life in the ocean

Conclusion

Bibliography

Introduction

The oceans are one of the few unique natural formations on our planet. It has many faces in perception: it arouses genuine interest, admiration, excites the imagination with an abyss and power, serves as a home, food and protection for its inhabitants. Water surface, occupying approximately 71% of the Earth's surface, which is almost 3/4 of the surface the globe a layer about 4000 m thick, still hides many mysteries. And no wonder: for thousands of years man "walked across the three seas", fished, and began to study him only three centuries ago.

Almost all living space is concentrated in the oceans. 4/5 of all living organisms are located under the surface of the ocean. V deep water zone the ocean, still poorly studied by man, is home to many species of animals.

Life in the ocean exists everywhere - from the surface to the very bottom and from the equator to the arctic latitudes. However, the variety of organisms and their saturation in water areas depend on many reasons. Among them, the main ones are depth, latitude, distance from the coast.

Purpose of work- to study the variety of living organisms of the World Ocean.

The ocean is the cradle of life on Earth

About 3.4 billion years ago, life began in the oceans. Only three billion years later, the first inhabitants appeared on land.

The development of life in it led to a change in the properties of water masses (salinity, gas content, etc.). For example, the appearance of green plants in the ocean led to an increase in the oxygen content in the water. Oxygen was released from the water into the atmosphere, changing its composition at the same time. The appearance of oxygen in the atmosphere has led to the possibility of the colonization of land by organisms originating from the oceans.

All inhabitants of the World Ocean, according to their habitat conditions, can be combined into 3 groups:

1) organisms that live on the surface of the ocean and in the water column and do not have active means movement;

2) organisms actively moving in the water column;

3) organisms living on the bottom.

Analysis of living organisms and their habitats suggests that the ocean is inhabited by organisms unevenly. Especially densely populated are coastal areas with depths of up to 200 meters, well lit and warmed up by the sun's rays. On the continental shelf, you can see forests and algae meadows - pastures for fish and other ocean dwellers. Away from the coast, large algae are rare, as Sun rays hardly penetrate the water column. Plankton reigns here (Greek planktos - wandering). These are plants and animals that are unable to withstand currents that carry them over considerable distances. Most of these organisms are very small, many of them visible only under a microscope. Distinguish between phytoplankton and zooplankton. Phytoplankton are various algae developed in the upper, illuminated water layer. Zooplankton inhabits the entire water column: these are small crustaceans, numerous protozoa (unicellular animals of microscopic size). Plankton is the staple food of most ocean dwellers. Naturally, the regions rich in them are also rich in fish. Baleen whales can also live here, in the diet of which plankton occupies the main place.

Benthos lives on the bottom of the sea or ocean (Greek benthos - deep). It is a collection of plant and animal organisms that live on the soil or in the soil of the seabed. Benthos includes brown and red algae, molluscs, crustaceans and others. Among them, shrimps, oysters, scallops, lobsters, and crabs are of great commercial importance. Bentos is an excellent food base for walruses, sea otters and some fish species.

The depths of the ocean are sparsely populated, but they are not lifeless. The plants, of course, are no longer there, but in complete darkness, under great pressure, in cold water swim amazing fish: they have huge toothy mouths, luminous bodies, "lights" on their heads. Some of them are blind, others can see poorly in the dark. They feed on the remains of organisms falling from above, or eat each other. The water column is home to many bacteria that live in the deepest water masses. Thanks to their activity, dead organisms decompose, and the elements necessary for the nutrition of living beings are released.

Actively moving organisms live everywhere in the ocean. These are a variety of fish, marine mammals (dolphins, whales, seals, walruses), sea snakes, squids, turtles and others.

Life in the ocean is distributed unevenly, not only in depth, but also depending on geographic latitude... Polar waters due low temperatures and long polar nights are poor in plankton. Most of all, it develops in the waters of the temperate zone of both hemispheres. Here currents, strong winds contribute to the mixing of water masses and the rise of deep waters, their enrichment with nutrients and oxygen. Due to the strong development of plankton, they develop and different kinds fish, therefore temperate latitudes are the most fishy areas of the ocean. In tropical latitudes, the number of living organisms decreases, since these waters are very hot, very salty and poorly mixed with deep water masses... In equatorial latitudes, the number of organisms increases again.

Diversity of living organisms in the ocean

The living world is huge and diverse : more than 150 thousand species of animals and more than 10 thousand species of algae live in it. Even now, when land animals and plants have developed, in aquatic environment there are much more of them than on land. The largest animals live here, for example a whale, which is 25 times heavier than an elephant - the largest animal on land; the largest plants are algae, tens of meters long. The living conditions in the water of all living things are much more favorable than on land: there is no sharp fluctuations temperature, surrounding water well supports the body of the organism in space and does not need such a powerful skeleton or roots, as the inhabitants of land, opposing the effects of the air element.

In the organic world of the seas and oceans stand out - and , and , that is, a set of organisms living on the ground and in the ground of seas, lakes, rivers. Benthos is divided into animal ( ) and vegetable ( ). More - especially in coastal shallow waters.

Remember

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

The distribution of organisms depending on the depth. With depth, the number of sunlight, oxygen dissolved in water, pressure builds up. The upper layer of water up to a depth of 100 m is well lit and contains a lot of oxygen. Therefore, this layer contains almost all the plants and all the plankton of the ocean.

The middle layer of water with twilight illumination extends to a depth of 1000 m. 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. Because of the complete darkness, deep-sea animals have developed special devices - the organs of luminescence. They are used to attract prey, camouflage or mislead the victim or hunter.

The inhabitants of the depths are under pressure from the water. How more depth, the higher the pressure. People, for example, cannot be at depth without special equipment. In deep-sea animals, the water pressure is balanced by the pressure of the liquid inside their organisms. Life in water layers with different pressures often affects the shape of the body of fish (Fig. 164).

Distribution of organisms depending on the climate. Due to climate change from the equator to the poles, the properties of water change in the same direction, and, consequently, the features of the organic world.

Life in the arctic and antarctic belts is very poor. There are few species of living organisms, as well as the individuals themselves. Plankton develops only in a short summer period and only in places free of ice. Following plankton, fish and walruses and seals feed on them.

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

Herring living in the upper layers of the ocean have a laterally compressed body. In sharks and tunas living at depth, the body is compressed from top to bottom and from the sides almost equally. In bottom rays and flounder, the body is flat, compressed from top to bottom.

V temperate zones the water temperature is above 0 ° С 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 they are actively fished here (herring, hake, cod, saury, salmon).

V tropical zones high water temperature all year round and increased salinity... There is little dissolved oxygen in the water and nutrients... Because of this, there is less plankton than in temperate zones, and therefore fish. However, in hot zones there is a huge variety of heat-loving fish and benthic organisms (corals, molluscs, echinoderms, crustaceans).

V equatorial belt the water temperature is high all year round. The rapid development of life is observed near the mouths large rivers carrying nutrients into the ocean. There are many coral structures at the bottom of the oceans. Fishing in equatorial waters sea ​​turtles, shellfish, tuna, sardines, mackerel.

Distribution 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. There is a lot of light, heat, nutrients in their shallow waters. Through active mixing, the water is enriched with oxygen. Towards the open ocean, the saturation of life decreases hundreds of times.

A rich world of benthic animals is found in areas of the ocean floor, where there are outcrops of hot groundwater and gases. Large mollusks live here, vestimentifera 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.

The shelf makes up about 9% of the area of ​​the entire World Ocean. However, 99% of all benthic organisms are concentrated here and more than 90% of all marine fish are caught.

Questions and tasks

1. What are the reasons for the diversity and number of organisms in different parts ocean?
2. How does it change organic world oceans with depth?
3. Why are there more living organisms in the coastal parts than in the open ocean?
4. In which climatic zone most marine organisms and why?

1. What plants and animals do you know live in the ocean?
2. How do the living conditions of organisms in the ocean differ from their living conditions on land?
3. How does man use marine organisms?

A variety of marine organisms. The ocean is full of life and mystery that boggles the mind. Many of them have not yet been disclosed. When researching deep sea and now organisms unknown to science are still being found.

Life in the ocean is all-pervading. It exists at the bottom of the Mariana Trench, at a depth of 11 thousand meters, and even where a new Earth's crust, where hot magma flows from the depths of the Earth through faults, where high temperatures and enormous pressure.

Living conditions in the ocean from the poles to the equator, from the surface to maximum depths very different. Therefore, the diversity of life in him is unusually great. (Prove this using knowledge from the 6th grade course. Tell us about the living conditions different groups organisms.)

A huge number of living organisms live in the oceans - from single-celled microscopic plants and animals to sea ​​giants... By way of life, marine organisms are divided into three groups: nekton - actively swimming animals; plankton - passively swimming and benthos - organisms living on the bottom.

Rice. 26. Fishing areas. Explain the reasons for this geography of fishing

The spread of life in the ocean. There are two areas of life in the ocean. The first includes the surface of the water and the entire water column, the second - the bottom of the ocean. What influences the spread of organisms in the boundless waters of the ocean? Light is the first condition for the existence of green algae in water, which other organisms feed on. There is less light in water than in air, and the illumination decreases with depth. Therefore, the upper 50-meter water column is most populated. However, here, too, organisms are distributed unevenly. There are more of them closer to the coast than in the open ocean. At the bottom of the ocean, more organisms are also found at shallow coastal depths.

In addition to light, other factors affect the distribution of organisms in the ocean: salinity and density, water temperature, the amount of nutrients, currents, vertical mixing of waters, as well as the properties of the rocks that make up sea ​​bottom... All these conditions are combined in different ways over the vast expanses of the ocean. For example, in areas where deep waters rise, the surface layer is fertilized with nutrients, which creates favorable conditions for life. The rise and mixing of waters is facilitated by storm winds and currents. In those places of the ocean where winds are rare, surface waters sink deep, they are poor in nutrients. There are few plant and animal plankton, as well as fish.

Rice. 27. Collecting shellfish

In the ocean, as well as on land, there is an alternation of belts with an increased and decreased mass of living organisms. The largest concentration of life in the ocean is typical for subpolar and temperate latitudes.

In the ocean, unlike land, where animals coexist with plants, green plants are absent below depths of 200-250 m. Here the ocean is inhabited only by animals and bacteria. The distribution of life in the ocean depends on the rate of supply of nutrients with upward movements of water, that is, it largely depends on the movement of waters.

Biological resources of the ocean. The ocean has long been the breadwinner of man. It is used for hunting for mammals (seals, walruses), for fishing, for invertebrates, and for collecting algae. Marine organisms used not only for food. They are used to obtain medicines, raw materials for the chemical industry.

The oceans have large, but still limited biological resources, and mankind faces important task their reasonable use, protection and multiplication.

Rice. 28. The ocean is rich in fish

1. What is the peculiarity of the spread of life in the ocean?
2. What determines the distribution of organisms in the surface layer of water?
3. Which parts of the ocean are especially rich in life? Explain why.
4. Why does ocean life require protection?

Living conditions in the ocean. V ocean water contains all the substances necessary for the life of organisms. Life in the ocean is all-pervading. 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 flows from the depths of the Earth through faults, where there are high temperatures and tremendous pressure.

Living conditions in the ocean from pole to equator, from surface to maximum depths are very different. Therefore, the diversity of life in the ocean is extraordinarily great. It is home to bacteria, unicellular plants that are invisible to the naked eye, and seaweed up to 80 m long, microscopic animals and huge blue whales. In terms of the variety of plant and animal species, the ocean is quite comparable to land.

The ocean is full of hidden life and mysteries that boggle the mind. Many of them have not yet been disclosed. When exploring the depths of the sea, organisms unknown to science are still being found.

According to most scientists, all life on our planet came out of the ocean, therefore 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 proliferation of oxygen-producing green plants in the ocean has led to an increase in the amount of oxygen in the water. It was released from the water into the atmosphere and changed its composition. The increase in the amount of oxygen in the atmosphere made possible the colonization of land by organisms from the ocean.

Distribution of organisms in the water column. The conditions for the existence of organisms in the water column and in the bottom areas are different. All marine organisms are divided into three groups according to their habitat conditions. 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 actively moving in the water column, and the third - organisms living at the bottom. Organisms that are in suspension in water and are not able to withstand the transfer of currents are called plankton (translated from Greek - wandering). Plankton is made up of algae and tiny animals. Plant plankton forms real "pastures" on which animal plankton develop.

In the water column, there are many bacteria that spread to the very depths. Thanks to the activity of bacteria, dead organisms decompose, and the substances necessary for the nutrition of living organisms again enter the biological cycle.

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

Life in the water column is unevenly distributed. Most of living organisms lives in the surface 100-meter layer illuminated by sunlight. In this layer, the distribution of life depends on the geographical latitude. Polar waters are poor in plankton due to low temperatures and long polar nights. A large number of plankton develops in the summer in the waters of temperate latitudes of both hemispheres. Here the currents strong winds promote mixing and rise of deep waters, their enrichment with nutrients and oxygen. Moderate latitudes (40 - 60 °) are the most fishy areas of the ocean.

In tropical latitudes, the number of living organisms decreases, since the water on the surface has elevated temperature, salinity and does not mix well with deep water masses. In equatorial latitudes, the number of organisms increases.

Distribution of life at the bottom of the ocean. The organisms of the bottom layers and the bottom itself include algae, corals, crustaceans, worms, molluscs, starfish, etc. Of the fish, flounder and halibut live here; octopuses live. The well-lit and warmed up coastal areas are especially rich in life. It receives a lot of nutrients from the land from the erosion of the coast 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 warm tropical waters, marine invertebrates live at the bottom - corals that form reefs and islands.

Biological resources of the ocean. The ocean has long been the breadwinner of man. There they hunt for mammals, fish, invertebrates, collect algae, catch krill - small crustaceans. Marine organisms are not only a source of food, but also drugs, raw materials for the chemical industry.

The oceans have large, but still limited biological resources, and mankind is faced with the important task of their wise use, protection and multiplication.