People have long been accustomed to the existence of a diverse animal and plant world on land. What do we know about life in the ocean? How diverse is it? Who, besides commercial fish, can be found in its waters? Let's look for answers to these questions together.
Amazing diversity
Life in the ocean is amazing and diverse. Scientists are sure that life began its development in the waters of the oceans. This can explain the fact that more than 150 thousand different species of representatives of the animal and plant world live here. If you try to calculate the total weight of all life forms of ocean waters, then the figure will turn out to be huge - in fact, it is 60 billion tons. The ocean as a habitat was suitable for all types of organic world. There are both simple organisms and huge mammals. Of the vast diversity of wildlife in the waters of the ocean, only spiders, centipedes and amphibians have not taken root.
Differences between water and air environments
Argue that air and water habitats differ in physical properties,futile. In the aquatic environment, temperatures are distributed differently, in accordance with the depth, the water pressure increases. And the presence of sunlight is observed only in the upper layers. These features of life in the ocean affect the existence and development of all life.
So, due to the fact that water is able to support organisms in a certain position, they do not need to form particularly strong skeletons or roots. Therefore, life in the ocean is represented by the largest mammal in nature, which is called the blue whale. This animal is 25 times heavier than the largest inhabitant of land - an elephant.
Well, since ocean algae do not have to resist the air element, they do not need to grow a powerful root system, but at the same time they can stretch for several tens of meters.
What is benthos?
This incomprehensible word defines the totality of living creatures that live on and in ocean soil. There are two varieties of life on the ocean floor: zoobenthos and phytobenthos. Representatives of the zoobenthos, that is, the animal world, are much larger, and as they approach the shores of the continents and islands, their number increases in shallow water.
Zoobenthos is represented by crustaceans, mollusks, large and small fish. Phytobenthos includes various bacteria and algae.
What is plankton?
What is life in the ocean without plankton? These are special living organisms that are not tied to the bottom, but are not able to actively move. In fact, all the movement of plankton occurs due to currents. The upper layers of water, where sunlight hits, inhabits phytoplankton. It consists of various types of algae. But zooplankton lives in the entire water column.
Most of the animal plankton are crustaceans and protozoa. These are various ciliates, radiolarians and other representatives. In addition, there are intestinal organisms: siphonophores, jellyfish, ctenophores and small pteropods.
Thanks to the huge amount of plankton, fish and aquatic animals are always provided with abundant food.
What is a nekton?
The term "nekton" is not very common, but it refers to life forms that we know very well. Nekton - organisms that can actively move in the water. These are turtles, and pinnipeds, and cetaceans. Nekton also includes all types of fish, squid, penguins and water snakes.
Zone division
Life in the ocean is interesting because it creates different conditions for the inhabitants of different depths. So, shallow water off the coast is called the littoral zone. Here, waves of water, ebbs and flows are common phenomena. This forced living organisms to adapt to the daily change of being in water and in the air. In addition, these organisms are constantly affected by temperature fluctuations, changes in environmental salinity and surf. To survive in these conditions, mollusks are firmly fixed on the rocks, crabs are held by tenacious claws, fish have acquired specialsuckers. And shrimp and starfish have learned to dig into the ground.
The next zone is bathyal. It starts at a depth of 200 m and ends at a depth of 2000 m. The bathyal zone is located within the continental slopes. The flora of this zone is very poor, because the sun's rays do not reach such a depth. But there are many fish here.
Further on, the habitat zone is called abyssal. It is located at depths of more than two kilometers. Here the water is slow moving and the temperature is consistently low. The salinity of the ocean at this depth can reach 34.7%, there is no light at all. Vegetation in this zone is represented by species of bacteria and algae. And the fauna of the ocean depths is very unusual. The bodies of animals are delicate and fragile. Many species have acquired long appendages in order to lean on viscous soil and be able to move around. Some living organisms have huge eyes, while others are completely absent. Many species of deep-sea fish are flat, some organisms are able to glow.
The deep-sea flora and fauna is still not fully understood, since descent to great depths is difficult not only for humans, but also for research instruments. Research with the help of self-propelled submersibles has become widespread. But the life of the littoral and bathyal zones is being actively studied.
The riches of the oceans give humanity a huge food source. And most importantly, this food source is saturated with vitamins and easily digestible protein. Suitable for foodrepresentatives of not only the animal, but also the plant world. The main thing is that a person should not consider this source inexhaustible and learn to treat it carefully and economically.
