Life in European seas and oceans. Biology lesson "Life in the seas and oceans" lesson plan in biology (grade 5) on the topic Life of organisms in the seas and oceans message

Question 1. Which natural communities seas and oceans do you know?

The seas and oceans can be compared to a huge house, which is inhabited from the highest to the lowest floors. Different natural communities develop on different floors of this house.

1) Coral reef community

2)Water surface community

3) Bottom community

4)Deep sea community

5)Water Column Community

Question 2. What creatures make up water surface communities and how are they connected to each other?

Relatives of jellyfish - sailfish - swim on the surface of the ocean. They have a flat oval body, like a raft, on which rises a triangular sail. The sailboat, like the boat, is a predator; it captures its prey with its tentacles. The flat body of the sailboat is similar to the deck of a ship; on it you can see “sailors” - small crabs. Having wanted to eat, such a crab carefully descends to the “bottom” of its living ship and snatches the caught crustaceans from its tentacles. Another “sailor” on the “deck” of a sailboat, the predatory mollusk yantin, is not so harmless: it eats away at the soft tissues of the sailboat. Marine water striders, similar to freshwater ones, live on the surface of the water. They often relax on the “deck” of a sailboat. And one of the flying fish lays eggs on the sailboat. All these organisms make up the surface water community.

Question 3. What two groups of organisms does the water column community include?

The water column community includes plankton and actively swimming organisms. Plankton (from the Greek word “planktos” - wandering) is the name given to all the many living creatures floating in the water column. These are a variety of algae, rayweeds, and crustaceans. They are all small and usually have outgrowths and bristles on their body so that water can better support them. Squids, various fish, dolphins, and whales swim actively. They have an elongated, streamlined body and strong muscles - devices for fast swimming. In the water column, food chains develop: crustaceans feed on algae, small fish feed on crustaceans, and more large fish, squid, dolphins. It is surprising that many whales, these giants of the sea, feed on plankton.

Question 4: List the organisms that make up the benthic community and the coral reef community.

The bottom community is very rich in species, developing at shallow depths. In addition to algae attached to the bottom, all kinds of mollusks with beautiful shells, sea anemones, hermit crabs, shrimps, sea ​​urchins And sea ​​stars, octopuses, and also many fish. Among them, flounders, stingrays, and anglerfish are especially famous.

The life of a coral reef community is even more diverse. Coral reefs are structures created by countless small sea animals - coral polyps. Reefs are common in warm tropical seas in shallow waters and resemble luxurious fairy gardens inhabited by many bizarre inhabitants. This community is one of the unique sea ​​wonders. In terms of richness of life it is second only to wet tropical forest on the land.

Question 5: What are the characteristics of a deep-sea community?

And at the great depths of the ocean, in eternal darkness, a special deep-sea community has formed. There are no plants here. There are some types of squid, shrimp, and bizarre-shaped fish. These inhabitants of the abyss feed on the dead remains of organisms that “fall” from upper layers water, and also predatory, eating each other. Many of the local inhabitants glow: some lure prey in this way, while others protect themselves from enemies by releasing a bright cloud, confusing predators.

Question 6. Remember why plants are not found in the ocean from a certain depth. Will they grow there if specially planted? Justify your answer.

Plants at great depths do not have enough light, and without it they cannot participate in the process of photosynthesis. If they are specially planted at great depths, they will not grow, since there is a shortage sunlight.

Question 7. Compare the conditions of existence of organisms in different aquatic communities. Where are the conditions most favorable?

All aquatic inhabitants, despite differences in lifestyle, must be adapted to the main features of their environment. These features are determined, first of all, physical properties water: its density, thermal conductivity, ability to dissolve salts and gases.

The density of water determines its significant buoyant force. This means that the weight of organisms in water is lightened and it becomes possible to lead a permanent life in the water column without sinking to the bottom. Many species, mostly small, incapable of fast active swimming, seem to float in the water, being suspended in it. The collection of such small aquatic inhabitants is called plankton. Plankton includes microscopic algae, small crustaceans, fish eggs and larvae, jellyfish and many other species. Planktonic organisms are carried by currents and are unable to resist them. The presence of plankton in water makes possible the filtration type of nutrition, i.e., straining, using various devices, small organisms and food particles suspended in water. It is developed in both swimming and sessile bottom animals, such as sea ​​lilies, mussels, oysters and others. A sedentary lifestyle would be impossible for aquatic inhabitants if there were no plankton, and this, in turn, is possible only in an environment with sufficient density.

The density of water makes active movement in it difficult, so fast-swimming animals, such as fish, dolphins, squids, must have strong muscles and a streamlined body shape. Due to the high density of water, pressure increases greatly with depth. Deep-sea inhabitants are able to withstand pressure that is thousands of times higher than on the land surface.

Light penetrates water only to a shallow depth, so plant organisms can only exist in the upper horizons of the water column. Even in the most clean seas photosynthesis is possible only to depths of 100-200 m. At greater depths there are no plants, and deep-sea animals live in complete darkness.

The temperature regime in reservoirs is milder than on land. Due to the high heat capacity of water, temperature fluctuations in it are smoothed out, and aquatic inhabitants do not face the need to adapt to severe frosts or forty-degree heat. Only in hot springs can the water temperature approach the boiling point.

One of the difficulties in the life of aquatic inhabitants is the limited amount of oxygen. Its solubility is not very high and, moreover, decreases greatly when the water is polluted or heated. That’s why there are sometimes freezes in reservoirs - mass death inhabitants due to a lack of oxygen, which occurs for various reasons.

Question 8: Why is a coral reef community the most species rich? Which terrestrial natural community is it similar to in terms of its wide variety of species?

Coral reefs are extraordinary places in the ocean. These ecosystems, the oldest and richest in natural communities on our planet, remain stable despite radical evolutionary changes in the entire terrestrial biota.

Reefs are common in warm, tropical seas in shallow waters and resemble luxurious fairy gardens inhabited by many bizarre inhabitants. This community is one of the unique wonders of the sea. In terms of richness of life, it is second only to tropical rainforests on land.

Question 9. Is it possible to appearance marine organisms say which natural community they belong to?

Animals that live in the water column and actively swim have a streamlined body and are lubricated with mucus, which reduces friction when moving. Developed devices to increase buoyancy: accumulations of fat in tissues, swim bladders in fish, air cavities in siphonophores. In passively swimming animals, the specific surface area of ​​the body increases due to outgrowths, spines, and appendages; the body is flattened, and skeletal organs are reduced. Different ways locomotion: bending of the body, with the help of flagella, cilia, reactive mode of locomotion (cephalomolluscs).

In benthic animals, the skeleton disappears or is poorly developed, body size increases, vision reduction is common, and tactile organs develop.

Question 10. Name the organisms shown in the picture and determine which communities they belong to.

The dolphin belongs to the community of the water column. Octopuses and deep sea fish live in a deep-sea community. Corals and sea anemones are representatives of the coral reef community. Fish are representatives of the water column community. Small crustaceans - plankton - representatives of the water surface community.

Routing.

Studentsmust be able to characterize the living conditions of organisms; identify traits of adaptation to certain conditions

Explain the essence of the concept “plankton”.

Give examples of flora and fauna of the seas and oceans based on the drawings in the textbook.

Create conditions for the formation of communicative universal actions, (work in a group, ability to negotiate, act together. Listen to others, take a different point of view); - create conditions for the formation of regulatory universal actions (develop the ability to set a goal, draw up a work plan, evaluate performance); - create conditions for the formation of cognitive universal actions (fill out the table, study the diversity of organisms living on different continents).

Show interest and curiosity in studying the topic. Responsible attitude towards nature; awareness of the need to protect the environment.

Basic concepts taught in class

plankton, attached organisms, free-swimming organisms.

№ stage

Lesson stage

UUD

Activity

EOR

Time

teachers

students

I

Organizational motivational

Target – student activation

Communication UUD:

Collaboration with teacher and peers

Greets students

Set the mood for positive emotions and fruitful work in the classroom.

Motivates students to work

Greetings from the teachers.

They stood up straight and turned around.

And they smiled at each other Let's sit down.

Let's remember the rules of behavior in the classroom:

If you want to answer, you need to raise your hand and, of course, stand up.

Motto:

From the one who learns,

Everything will always work out!

1 min

Updating knowledge

Target: repetition of previously studied material necessary for the “discovery of new knowledge.”

Communicative - planning educational Collaboration with the teacher and peers.Regulatory:volitional self-regulation.Personal: the action of meaning-making

How prepared are you for class today?

Conversation on issues

1. List what adaptations of organisms you know to environment? Give examples.

2. Determine from the card - what examples of devices do you see? (We work in pairs).Self-esteem

3. individually: fill out the table - adaptations to winter conditions, and do a mutual check with your desk neighbor. We sign our table at the top.Self-esteem

Answer questions.

Use individual cards

Working with a table.

Self-assessment on the score sheet.

presentation.

Motivation to educational activities and goal setting

Target: formulation of the topic.

cognitive - analysis of objects in order to identify features.Regulatory: goal setting as setting an educational task, forecasting. communicative - planning educational cooperation with the teacher and peers.

Guys! We continue to study the flora and fauna.

What do you see on the slide? That's right, this is a view of the Earth from space. Which color is dominant? (blue, light blue) Why? (denotes bodies of water on the planet - oceans and seas)

In order to correctly determine the topic of the lesson, try to guess the riddles correctly.

Puzzles.

1. It consists of seas

Well, come on, answer quickly

Is not glass of water,

And the huge ………….. ocean

2. Without end and edge Puddle
She is not afraid of the evil cold.
Ships sail in Luzha,
The sea is far from them

3. Both long and short,

And one does not believe one;

Everyone measures for himself. life

    (Slide). The topic of our lesson: “The life of organisms in the seas and oceans.”

    And we are going on a virtual walk to the sea. Let's think about the purpose for which you will take this walk, what you want to learn. Why is it necessary to study life in the seas and oceans?(ask several people)

You are absolutely right. Your goals match mine.

(Get acquainted with the inhabitants of the seas and oceans, with the peculiarities of living conditions and the adaptation of animals to them).

QUESTIONby formulationProblems: Guys, do you know in which layer of water which ones live? aquatic organisms?

PROBLEM?“How the seas and oceans are populated by living organisms.”

In order to solve this problem and achieve the desired goal -what we are missing -KNOWLEDGE

Propose a plan of your actions where you will gain knowledge.

From what sources will you obtain knowledge to solve your problem?(Textbook, computer, additional material).

Determine the topic of the lesson from the words ocean, sea, life.

Students set a goal for the lesson.Students clarify and agree on the topic of the lesson.

They pose a problem.

“How the seas and oceans are populated by living organisms”

Students’ perception and comprehension of new material

cognitive - search and selection of necessary information, the ability to structure knowledge. communicative - cooperation in searching for information

regulatory – planning, forecasting.

Earthly life originated in water. Everything that now crawls, runs and grows on the ground, everything that flies above the ground and everything that digs underground - everything once came out of the sea. This means that we people also began in the sea.. (slide 3)

Our body is still half made of water, our arms and legs are former pectoral and pelvic fins fish Our lungs were formed from a fish's swim bladder. Our heart pumps blood through our veins(WHAT DOES IT TASTE? ) salty like sea water, and the beats of our pulse are as rhythmic as the ebb and flow of the sea.

For millions amazing creatures sea ​​- native home. The house is not simple - multi-story. (slide 4) Let's walk with you through the floors of this house and get to know its inhabitants, solve their main life problems.

WORKING WITH THE TEXTBOOK pp. 99-103. in GROUPS on assignments.

Group 1: Marine inhabitants of shallow and open water.

2 group-inhabitants open water.

Group 3 - inhabitants of the seabed and deep sea.

So, to begin their exploration, each group must have a guide map. This map is for exploring each floor in an envelope. The envelope is in shallow water! Find this envelope and get started.

Working with the textbook (work in groups)

Work with text.

(group work)

Envelopes with a map and guide (under the desk on tape)

Initial check of understanding

Regulatory: control in the form of comparison of the method of action and its result with a given standard, correction,

communicative – proactive cooperation in searching for information. cognitive – building a logical chain of reasoning and evidence.

Report on completed work.

At the blackboard.

Work in groups.

Self-assessment of group work

Physical education moment

We will all stand together now,
We'll rest at the rest stop...
Turn right, turn left!
Bend over and bow!
Hands up and hands to the side
And jump and jump on the spot!
And now we're skipping,
Well done, you guys!

Primary consolidation

Regulatory: volitional self-regulation Communicative: the ability to express one’s thoughts; cognitive – the choice of bases and criteria for comparison.

And now we will consolidate the knowledge gained from our comrades during your journey. Suddenly a storm came and gathered all our sea inhabitants into one heap.The representative of group 1 needs to select the inhabitants of open water and move them to his floor. And the second group will check the correctness of the task.

The representative of the second group will choose deep sea inhabitants sea ​​and will help them return to their floor. And the third group will check.

And finally, group 3 will help the shallow water inhabitants return home. – Group 1 will check.

Group work.

SELF-ESTEEM

Analysis

Regulatory – students’ identification and awareness of what has already been learned and what still needs to be learned, assessment of the quality and level of assimilation. Personal - self-determination.

Ecological fairy tale. There lived an old man with an old woman blue sea. Grandfather threw a net. A net came with sea mud, glass bottles and garbage. I threw it a second time and caught a torn shoe and rusty cans. And among them gold fish. Don’t let me go into the blue sea, old man, I’ll die there. Sad tale? This is actually true. We humans throw a lot of dirt into the oceans and seas. We harm the inhabitants. The ocean world is very large and beautiful. It is impossible to talk about all the inhabitants in one lesson. But protecting it is not only possible, but also necessary.

Reflection

Communication skills express your thoughts with sufficient completeness and accuracy. Cognitive – reflection. Personal – meaning formation, goal setting.

I enjoyed my lesson today……..

Before the lesson started, I thought that……., but now I know…….

I did not like…

Where the knowledge learned will be needed.

On the board, fill an empty aquarium with fish of the corresponding color:

red - learned all the lesson material and accepted Active participation at work.

Blue - If you need to repeat or read more.

Green - they didn’t understand the lesson material well.

Write down homework

Homework

    Everyone § 23.

    Optional: study additional material on the topic.

    Creative task: write a mini-essay about any sea creature.

Compose a crossword puzzle “Inhabitants of the seas” of 7-10 words

We hand over evaluation sheets and notebooks.

Task card.

Practical work"Looking at cards sea ​​creatures"

Review the cards

Write the names of the animals in the table.

Determine the features of adaptation to life in a particular community (ways to solve the problem).

See pages 135-137

Additional material

Marine inhabitants of shallow waters . Imagine that you are going on a voyage on a marine research ship. There are scientists on board the ship who will explore the life of sea creatures, map the seabed, measure speed sea ​​currents, temperature and salinity of water at different depths and perform many more important works.

The ship leaves the pier and you notice the inhabitants of the shallow water. Numerous shell mollusks - mussels - are visible on large stones (Fig. 87). They are attached to the surface of the stones using special adhesive threads, so the surf waves cannot tear them out of place. Other shellfish, such as oysters, and algae also adhere firmly to the stones. Mussels, oysters, seaweed - thisattached organisms.

A little further from the shore, small mounds are visible on the sandy bottom. At the top of such a mound, round holes leading into the burrow are visible. The sandworm sea worm lives here. It feeds in the same way as an earthworm on land - it swallows the soil in which it lives and digests everything edible that happens to be there.

Something moved at the very bottom: it was a fish - a stingray. The stingray's body is flat and colored to match the color of the soil, so when it lies motionless on the bottom, it is almost invisible. Other marine inhabitants, such as flounder, can also hide.

Living on the seabed provides a number of advantages to its inhabitants. Here you can easily hide - bury yourself in silt and sand, hide among stones or among algae (Fig. 88). Large ones cannot penetrate into shallow waters. predatory fish(sharks). But there are other dangers here - breaking waves, ebbs and flows, seabirds.

Open water inhabitants . The ship went out to the open sea. A school of dolphins appeared in the distance. You can see fish in the water column. Among the fastest are sharks and tuna (Fig. 89). Thisfree-swimming organisms. There is nowhere to hide in open water. Only swimming speed gives an advantage in survival. Therefore, the inhabitants of the open sea have a streamlined body and powerful muscles, allowing them to develop great speed.

The scientists lowered a bucket from the side of the ship and scooped up sea ​​water. In it they discovered a huge variety of tiny creatures - microscopic crustaceans, tiny jellyfish, a large number of unicellular algae, ciliates, mollusk larvae (Fig. 90). Such floating and floating plant and animal organisms in water are calledplankton (from the Greek wordplanktos - “wandering”) Plankton lives in the waters of all seas and oceans; it is food for fish and some whales. The richest "plankton pastures" are found in the cold Southern Ocean surrounding Antarctica and in the cold northern waters Atlantic and Pacific oceans. There is also a lot of plankton living off the coasts of Chile, Peru, Namibia and some other countries. Whales, which feed on plankton, regularly travel thousands of kilometers to swim from one “pasture” to another.

Life in the depths of the sea . The ship is preparing to dive deep-sea vehicle- bathyscaphe. In the submersible you can go down to a depth of more than a kilometer. It is completely dark here: sunlight does not pass through the water column, and algae do not grow here - at depths of more than 150 m there is not enough light for photosynthesis. In this zone of oisin, special conditions reign. Vedas and special inhabitants live. For example, fish live here that spend their entire lives at great depths and never rise to the surface. These are the anglerfish (Fig. 91). Their body is covered with dark skin. The large mouth is armed with powerful teeth. These fish can swallow prey that is larger than them. On

On the head or back of the anglerfish there is a long flexible outgrowth - a “fishing rod” with a luminous bait.

Like the inhabitants of other areas of the sea, deep-sea fish are perfectly adapted to their living conditions.

1) Specify environmental factors, the most significant for the inhabitants of the aquatic environment.

    Answer: Density of the medium, pressure, temperature regime, light, oxygen, salt composition.

2) Fill out the table “Inhabitants of shallow waters.”

3) Answer questions about plankton.

A) What are the characteristics of the organisms that make up plankton?

    Answer: Microscopic hovering or swimming animals or plants.

b) What is the main difference between planktonic organisms and fish (sharks, tuna)?

    Answer: Small sizes.

V) What is the importance of plankton?

    Answer: They serve as food for aquatic life.

4) Describe the features of organisms living in the open waters of seas and oceans.

    Answer: Inhabitants of open waters have powerful fins and a streamlined body shape

5) Look at the picture, compare the structure of the fish shown and determine in which part of the water column of the sea they live. Justify your opinion.

    Answer: 1. Flounder is a flat bottom fish that has the ability to mimic (merges with sand).

    1. Tuna - lives in open waters: a torpedo body, constantly moving, has a large leathery keel.
    2. Rag Pipit - the head and body are covered with processes imitating algae thalli. They are found on coral reefs and in shallow waters.

6) Using additional literature and the Internet, prepare a report on deep-sea marine life. Write a message outline.

  • Answer: 1. Living conditions in deep water

    1. Plants - are they present in deep water?
    2. Deep sea plankton
    3. Deep sea fish.

Let's summarize - what have you learned about the life of living organisms in different parts of the Earth?

1) Fill the table.

  • Functions of organisms in natural communities

    Organism

    Plants

    Producers

    Animals

    Consumers

    Decomposers

    Bacteria

    Decomposers and producers

2) Explain what adaptations a shark and an anglerfish have that are related to the conditions in which they live.

  • Answer: Shark: streamlined body shape, powerful fins, gills.

    Anglerfish: a powerful body shape, thanks to which it can withstand water pressure and a “fishing rod” with a flashlight, which helps the anglerfish see, because Light does not penetrate well to the bottom.

3) Choose the correct answer and mark it.


The seas and oceans can be compared to a huge house, which is inhabited from the highest to the lowest floors. Different natural communities develop on different floors of this house. We will begin our acquaintance with them from the surface of the water.

Here is a small one floating (about 30 cm in length) strange creature. Blue with a red sail. This animal with the unusual name is the Portuguese man-of-war (in the old days the Portuguese brightly painted their warships). This creature is a relative of jellyfish. It doesn't sink because it has a large, light air bubble. On top of this bubble there is a ridge, which serves as a sail. And long tentacles go down into the water. With their help, the boat catches its food: crustaceans, fish.

Other relatives of jellyfish - sailfish - also swim on the surface of the ocean. They have a flat oval body, like a raft, on which rises a triangular sail. The sailboat, like the boat, is a predator; it captures its prey with its tentacles. The flat body of the sailboat is similar to the deck of a ship; on it you can see “sailors” - small crabs. Having wanted to eat, such a crab carefully descends to the “bottom” of its living ship and snatches the caught crustaceans from its tentacles. Another “sailor” on the “deck” of a sailboat, the predatory mollusk yantin, is not so harmless: it eats away at the soft tissues of the sailboat. Marine water striders, similar to freshwater ones, live on the surface of the water. They often relax on the “deck” of a sailboat. And one of the flying fish lays eggs on the sailboat. All these organisms make up water surface community.

Water Column Community includes plankton and actively swimming organisms. Plankton (from the Greek word “planktos” - wandering) is the name given to all the many living creatures floating in the water column. These are a variety of algae, rayweeds, and crustaceans. They are all small and usually have outgrowths and bristles on their body so that water can better support them. Squids, various fish, dolphins, and whales swim actively. They have an elongated, streamlined body and strong muscles - devices for fast swimming. In the water column, food chains develop: crustaceans feed on algae, small fish feed on crustaceans, and larger fish, squid, and dolphins feed on them. It is surprising that many whales, these giants of the sea, feed on plankton.

Very rich in species benthic community, folding at shallow depths. In addition to algae attached to the bottom, all kinds of mollusks with beautiful shells, sea anemones, hermit crabs, shrimp, sea urchins and starfish, octopuses, and many fish live here. Among them, flounders, stingrays, and anglerfish are especially famous.

Living beings are even more diverse in coral reef community. Coral reefs are structures created by countless small marine animals called coral polyps. Reefs are common in warm tropical seas in shallow waters and resemble luxurious fairy gardens inhabited by many bizarre inhabitants. This community is one of the unique wonders of the sea. In terms of richness of life, it is second only to tropical rainforests on land.

And at the great depths of the ocean, in eternal darkness, a special deep-sea community has formed. There are no plants here. There are some types of squid, shrimp, and bizarre-shaped fish. These inhabitants of the abyss feed on the dead remains of organisms that “fall” from the upper layers of water, and also prey, eating each other. Many of the local inhabitants glow: some lure prey in this way, while others protect themselves from enemies by releasing a bright cloud, confusing predators.

Test your knowledge

  1. What natural communities of seas and oceans do you know?
  2. What creatures make up the surface water community and how are they related to each other?
  3. What two groups of organisms does the water column community include?
  4. List the organisms that make up the benthic community and the coral reef community.
  5. What are the characteristics of a deep sea community?

Think!

  1. Compare the living conditions of organisms in different aquatic communities. Where are the conditions most favorable?
  2. Why is a coral reef community particularly rich in species?
  3. Is it possible to tell by the appearance of marine organisms which natural community they belong to? Give examples.
  4. Name the organisms shown in the picture and determine which communities they belong to.

The seas and oceans are richly populated by living organisms. A variety of natural communities are formed here: the surface water community, the water column community, the bottom community and the coral reef community, and the deep-sea community.

The world's 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 the 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, which is known to contain liquid water.

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

To understand ocean life, you must first know its definition. The phrase "marine life" covers all organisms living in salt water, which includes a wide variety of plants, animals and microorganisms such as bacteria and.

There is a huge variety of marine species that range from tiny single-celled 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 ocean flora and fauna. The following is a list of the major types or taxonomic groups of living organisms in the oceans:

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

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

Marine Life Adaptations

From the perspective of a land animal like us, the ocean can be a harsh environment. However, marine life is adapted to life in the ocean. Characteristics that help organisms thrive in marine environment, include the ability to regulate salt intake, organs for obtaining oxygen (for example, fish gills), withstand increased water pressure, adaptation to lack of light. Animals and plants living in the intertidal zone 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;
  • Obtaining oxygen;
  • Adaptation to water pressure;
  • Waves and changes in water temperature;
  • Getting enough light.

Below we look at some of the ways marine life can survive in this environment, which is very different from our own.

Salt regulation

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

Oxygen

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

Marine mammals must come to the surface to breathe, so whales have breathing holes on the top of their heads, allowing them to inhale air from the atmosphere while keeping most of their body submerged.

Whales are able to remain underwater without breathing for an hour or more because they use their lungs very efficiently, filling up to 90% of their lung capacity with each breath, and also store unusually large amounts of oxygen in their blood and muscles when diving.

Temperature

Many ocean animals are cold-blooded (ectothermic), and their internal body temperature is the same as their environment. The exception is warm-blooded (endothermic) marine mammals, which must maintain constant temperature your body, regardless of the water temperature. They have a subcutaneous insulating layer consisting of fat and connective tissue. This layer of subcutaneous fat allows them to maintain their core body temperature about the same as that of their land-based relatives, even in the cold ocean. The bowhead whale's insulating layer can be more than 50 cm thick.

Water pressure

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

It is believed that the sperm whale is capable of diving more than 2.5 km below the ocean surface. One adaptation is that the lungs and chest shrink when diving to great depths.

Leathery sea ​​turtle can dive to more than 900 meters. Folding lungs and a flexible shell help them withstand high water pressure.

Wind and waves

Intertidal animals do not need to adapt to high water pressure, but must withstand strong wind and wave pressure. Many invertebrates and plants in this region 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 storms, their prey may be displaced. For example, whales hunt copepods, which can be scattered across different remote areas during strong wind and waves.

sunlight

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

Because underwater visibility and light levels can change, 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 have lost their eyes or pigmentation because they simply are not needed. Other organisms are bioluminescent, using light-producing organs or their own light-producing organs to attract prey.

Distribution of life in 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 particular marine environment.

Euphotic zone

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

Sunlight in the photic zone allows the process of photosynthesis to occur. 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 is carried out by 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 patches in the ocean, which are the foundation of oceans and seas. Through photosynthesis, phytoplankton are responsible for producing 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 humans.

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 because 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. The fish in this area are small and luminous.

Bathypelagic zone

Sometimes animals from the mesopelagic zone (such as sperm whales and squid) dive into the bathypelagic zone, which reaches depths of about 4,000 meters. The bathypelagic zone is also known as the midnight zone because light does not reach it.

Animals living in the bathypelagic zone are small, but they often have huge mouths, sharp teeth and expanding stomachs that allow them to eat any food that falls into their mouths. Most of this food comes from the remains of plants and animals descending from the upper pelagic zones. Many bathypelagic animals do not have eyes because they are not needed in the dark. Because the pressure is so high, it is difficult to find nutrients. Fish in the bathypelagic zone move slowly and have strong gills to extract oxygen from the water.

Abyssopelagic zone

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

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

Ultra Abyssal

The deepest zone of the ocean, found in faults and canyons, is called the ultra-abyssal. Few organisms live here, such as isopods, a type of crustacean related to crabs and shrimp.

Such as sponges and sea ​​cucumbers, thrive in the abyssopelagic and ultraabyssal zones. Like many starfish and jellyfish, these animals depend almost entirely on the settling remains of dead plants and animals called marine detritus.

However, not all bottom dwellers depend on marine detritus. In 1977, oceanographers discovered a community of creatures on the ocean floor feeding on bacteria around openings called hydrothermal vents. These vents release hot water enriched with minerals from the depths of the Earth. The minerals feed unique bacteria, which in turn feed animals such as crabs, clams and tube worms.

Threats to Marine Life

Despite relatively little understanding of the ocean and its inhabitants, human activity has caused enormous harm to this fragile ecosystem. We constantly see on television and in newspapers that yet another marine species has become endangered. The problem may seem depressing, but there is hope and many things each of us can do to save the ocean.

The threats presented below are not in any particular order, as they are more pressing in some regions than others, and some ocean creatures face multiple threats:

  • Ocean acidification- If you've ever owned an aquarium, you know that the correct pH of the water is an important part of keeping your fish healthy.
  • Changing of the climate- we constantly hear about global warming, and for good reason - it negatively affects both marine and terrestrial life.
  • Overfishing is a worldwide problem that has depleted many important commercial species fish.
  • Poaching and illegal trade- despite laws passed to protect marine life, illegal fishing continues to thrive to this day.
  • Networks - 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 debris, as well as in nets, and oil spills cause enormous damage to most marine life.
  • Habitat loss- as the world's population grows, anthropogenic pressure on coastlines, wetlands, kelp forests, mangroves, beaches increases, rocky shores and coral reefs that are home to thousands of species.
  • Invasive species - species introduced into a new ecosystem can cause serious harm to their native inhabitants, since due to the lack of natural predators they may experience a population explosion.
  • Seagoing 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, leading to the release chemical substances into the ocean and atmosphere.
  • Ocean noise - there is a lot of natural noise in the ocean that is an integral part of this ecosystem, but artificial noise can disrupt the rhythm of life of many marine inhabitants.
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