Animals and plants of the Indian Ocean: photos and descriptions of underwater inhabitants. The organic world of the Indian Ocean

The richest source for a variety of life is the ocean. Any of the five oceans existing on our planet is a real treasure of the organic world. Moreover, if terrestrial animals are known to science, then some inhabitants of the depths remain undiscovered until now, skillfully hiding in the bowels of the ocean.

This only spurs the interest of zoologists, oceanographers and other scientists. The study of the ocean, from its physical characteristics to the diversity of life in it, is at the forefront today. Consider the organic world of the Indian Ocean as one of the richest in living systems.

Characteristics of the Indian Ocean

Among other oceans, the Indian is in third place in terms of the occupied water area (after the Atlantic and Pacific). The properties of the Indian Ocean can be characterized by several main points:

1. The territory of the ocean is about 77 million km 2.
2. The organic world of the Indian Ocean is very diverse.
3. The volume of water is 283.5 million m 3.
4. The width of the ocean is about 10 thousand km 2.
5. Washes all over the world in Eurasia, Africa, Australia and Antarctica.
6. Bays (straits) and seas occupy 15% of the entire ocean area.
7. The largest island is Madagascar.
8. The deepest depth near the island of Java in Indonesia is more than 7 km.
9. The average total water temperature is 15-18 0 C. In each separate place of the ocean (near the borders with islands, in seas and bays), the temperature can differ markedly.

Indian Ocean exploration

This water body has been known since antiquity. It was an important link in the trade of spices, fabrics, furs and other goods between the peoples of Persia, Egypt and Africa.

However, the exploration of the Indian Ocean began much later, during the time of the famous Portuguese navigator Vasco da Gama (mid-15th century). It is to him that the merit of the discovery of India belongs, after which the entire ocean was named.

Before Vasco da Gama, he had many different names among the peoples of the world: the Eritrean Sea, the Black Sea, Indicon Pelagos, Bar el-Hind. However, even in the 1st century, Pliny the Elder called him Oceanus Indicus, which is translated from Latin as "Indian Ocean".

A more modern and scientific approach to the study of the structure of the bottom, the composition of waters, inhabitants of animal and plant origin began to be carried out only in the 19th century. Today, the fauna of the Indian Ocean is of great practical and scientific interest, as is the ocean itself. Scientists from Russia, America, Germany and other countries are actively engaged in this issue, using the most advanced technology (underwater devices, space satellites).

The picture of the organic world

The organic world of the Indian Ocean is quite diverse. Among the representatives of flora and fauna, there are species that are very specific and rare.

In terms of its diversity, the ocean biomass resembles that of the Pacific Ocean (more precisely, in its western part). This is due to the common underwater currents between these oceans.

In general, the entire organic world of the local waters can be combined into two groups according to their habitat:

1. Tropical Indian Ocean.
2. Antarctic part.

Each of them is characterized by its own climatic conditions, currents, abiotic factors. Therefore, organic diversity also differs in composition.

Variety of life in the ocean

The tropical area of ​​this body of water abounds in a variety of planktonic and benthic animal and plant species. Algae such as unicellular trichodesmia are considered common. Their concentration in the upper layers of the ocean is so high that the overall color of the water changes.

Also in this area, the organic world of the Indian Ocean is represented by the following types of algae:

• sargassum algae;
• turbinariums;
• caulerps;
• phytotamnias;
• khalimad;
• mangroves.

Of the small animals, the most widespread are the beautiful representatives of plankton glowing at night: physalia, siphonophores, ctenophores, tunicates, peridenea, jellyfish.

Fancy fish

Often the animals of the Indian Ocean are rare or simply unusual in appearance. So, among the most common and numerous fish there are sharks, rays, mackerels, coryphans, tuna, notothenia.

If we talk about unusual representatives of the ichthyofauna, then it should be noted such as:

• coral fish;
• parrot fish;
• White shark;
• whale shark.

Tuna, mackerel, coriphenes and notothenia are of commercial importance among fish.

Variety of animals

The fauna of the Indian Ocean has representatives of the following types, classes, families:

1. Fishes.
2. Reptiles (sea snakes and giant turtles).
3. Mammals (sperm whales, seals, sei whales, elephant seals, dolphins, toothless whales).
4. Molluscs (giant octopus, octopus, snails).
5. Sponges (lime and silicon molds);
6. Echinoderms (sea beauty, sea cucumbers, sea urchins, ophiuras).
7. Crustaceans (crayfish, crabs, lobsters).
8. Hydroid (polyps).
9. Bryozoans.
10. Coral polyps (form coastal reefs).

Animals such as the sea beauties are very bright in color, live at the very bottom and have a hexagonal shape with a radial symmetry of the body. Thanks to them, the ocean floor looks bright and picturesque.

The giant octopus is a large octopus, the length of the tentacles of which extends to 1.2 m. The body is, as a rule, no more than 30 cm in length.

Calcareous and silicon sponges play an important role in the formation of the Indian Ocean floor. Along with benthic algae species, they form whole deposits of calcareous and siliceous deposits.

The most terrible predator of these habitats is the white shark, which reaches 3 meters in size. A ruthless and very agile assassin, she is practically the main threat of the Indian Ocean.

Very beautiful and interesting fish of the Indian Ocean - coral fish. They are bizarre and brightly colored, have a flat, elongated body shape. These fish are very dexterous in hiding in thickets of coral polyps, where not a single predator is able to reach them.

The combined conditions of the Indian Ocean allow its fauna to be so diverse and interesting as to attract those wishing to study it.

Vegetable world

The outline map of the Indian Ocean gives a general idea of ​​what it borders on. And based on this, it is easy to imagine what the ocean plant community will be like.

The proximity to the Pacific Ocean contributes to the widespread distribution of brown and red algae, many of which are of commercial importance. Green algae are also found in all parts of the Indian Ocean.

The thickets of the giant macrocystis are known as interesting and unusual. It is believed that getting into such thickets on a ship is tantamount to death, because it is very easy to get entangled in them and it is completely impossible to get out.

The main part of the ocean flora is made up of unicellular benthic, planktonic algae.

Commercial value of the Indian Ocean

Fishing for animals and plants in the Indian Ocean is not as fully developed as in other deep oceans and seas. Today this ocean is the world's source of supply, a reserve of valuable sources of food. A contour map of the Indian Ocean can show the main islands and peninsulas where the most developed fishing and harvesting of valuable species of fish and algae are:

• Sri Lanka;
• Hindustan;
• Somalia;
• Madagascar;
• Maldives;
• Seychelles;
• Arabian Peninsula.

At the same time, the animals of the Indian Ocean for the most part are very nutritious species. However, this water body is not very popular in this sense. Its main importance for people today is access to different countries of the world, islands and peninsulas.

Climate and hydrological regime of the waters of the Indian Ocean. Hydrological resources.

Climate. In the region there are 4 climatic. belts. Influenced by Asians. continent in the north. parts of Indus. The ocean is characterized by a monsoon climate with frequent cyclones moving towards the coasts. High atm. pressure over Asia in winter causes northeast formation. monsoon. In summer, it is replaced by a humid southwest. monsoon, carrying air from the southern regions of the ocean. During the summer monsoon winds are often stronger than 7. Summer pace. over the ocean = 28-32 ° C, in winter 18-22 ° C. To the south. the tropics of the lords. southeast. trade wind, cat. in winters. time does not extend north of 10 ° N. Wed
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year. temp. = 25 ° C. In the zone 40-45 ° S lat. throughout the year - app. air transfer masses. In zap. parts of the ocean hurricanes occur (up to 8 times a year), in the districts of Madagascar and the Mascarene Islands. Into the subtrope. and died.
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lat.
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in summer temp. = 10-22 ° C, and in winter - 6-17 ° C. Strong winds are typical from 45 degrees and further south. In winter, the temperature here ranges from -16 ° C to 6 ° C, and in summer - from -4 ° C to 10 ° C. Max. the amount of precipitation (2.5 thousand mm) - in the east. the equator area.
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zones. The least amount of precipitation is observed in the trails. r-nah south. hemisphere.

Hydrological regime. Winter: South-West. monsoon. te, start. in the Bay of Bengal. South of 10 ° N this current passes to the West. leech. Then it branches: 1 branch goes to the sowing. to the Red Sea, 2- to the south to 10 ° S lat. and, turning to the east, gives rise to the Equatorial Countercurrent. The latter crosses the ocean and off the coast of Sumatra is again divided into a part that goes into the Andaman Sea and the main branch, which between the Lesser Sunda Islands and Australia goes to the Pacific Ocean. The summer monsoon current begins off the coast of Africa with a powerful Somali current, to which the current from the Red Sea joins in the Gulf of Aden. In the Bay of Bengal, the summer monsoon current splits northward.
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and south., ĸᴏᴛᴏᴩᴏᴇ merges into the South. Tradewind current. South Passat. tech crosses the ocean from the east. on app. to Madagascar. Madagascar South. Passat. the current forks, giving rise to the Equatorial countercurrent, the Mozambique and Madagascar currents. Merging southwest of Madagascar, they form the warm Agulhas current. South part of this flow goes to Atlantich. ocean, and part of it flows into the current West. winds. On the way to Australia, the cold recedes to the north from the latter. Western Australian Current.

Temperature, salinity of water. In the equatorial zone, the surface water temperature is about 28 ° C all year round. High winter water temperatures (up to 29 ° C) are characteristic of the coast of northwestern Australia. Pace. water below 0 ° C in years. time is noted south of 60 ° S latitude. Ice formation in these areas begins in April and the fast ice thickness reaches 1-1.5 m by the end of winter. By March, the waters are completely cleared of fast ice. To the south. parts of the ocean icebergs are common.

Max. salinity of waters in the Persian Gulf. and the Red Sea, where it = 40-41 ‰. High salinity (more than 36 ‰) is also observed in the south. trope. belt and the Arabian Sea. Decreased salinity (less than 34 ‰) is characteristic of the Arctic waters, where the strong desalination effect of melt glacial waters affects.

Flora and fauna of the Indus. OK. unusually diverse. Tropic. the region stands out for the richness of plankton. The unicellular alga Trichodesmia (a type of Cyanobacteria) is especially abundant, due to which the surface layer of water becomes very cloudy and changes its color. Plankton Ind. the ocean is distinguished by a large number of organisms glowing at night: peridinea, some species of jellyfish, ctenophores, tunicates. Brightly colored siphonophores are abundant, incl. poisonous phasalia. In temperate and arctic waters, the main representatives of plankton are copepods, euphausids and diatoms. The most abundant fish in the Indian Ocean are coryphans, tuna, notothenium and a variety of sharks. From reptiles there are several species of giant sea turtles, sea snakes, from mammals - cetaceans (toothless and blue whales, sperm whales, dolphins), seals, elephant seals. Most cetaceans live in the temperate and circumpolar regions, where, due to the intensive mixing of waters, favorable conditions for the development of planktonic organisms arise. Birds are represented by albatrosses and frigates, as well as several species of penguins that inhabit the coasts of South Africa, Antarctica and islands lying in the temperate zone of the ocean.

The flora of the Indus. the ocean is represented by brown (sargassum, turbinaria) and green algae (caulerna). Lithotamnia and khalemeda calcareous algae also flourish, which together with corals participate in the construction of reef buildings. In the course of the activity of rift-forming organisms, coral platforms are created, sometimes reaching a width of several kilometers. Typical for the coastal zone of the Indian Ocean is a phytocenosis formed by mangrove thickets. Especially such thickets are characteristic of river mouths and occupy significant areas in Southeast Africa, Western Madagascar, Southeast Asia and other regions. For temperate and Antarctic waters, red and brown algae are most characteristic, mainly from the groups of fucus and laminaria, porphyry, and gelidium. In the circumpolar regions of the southern hemisphere, giant macrocystis are found.

Zoobenthos is represented by a variety of molluscs, calcareous and flint sponges, echinoderms (hedgehogs, starfish, ophiura, holothurians), numerous crustaceans, hydroids, and bryozoans. Coral polyps are widespread in the tropical zone.

The organic world of the Indian Ocean. Biological resources. - concept and types. Classification and features of the category "Organic world of the Indian Ocean. Biological resources." 2017, 2018.

Physical geography of continents and oceans

OCEANS

INDIAN OCEAN

Features of the organic world of the Indian Ocean

Fauna and flora of the Indian Ocean have likeness with the organic world of the Pacific Ocean, which is explained by the wide exchange between these oceans through the seas and straits of the Indonesian archipelago ”(O.K. Leontiev).

Especially rich in organic life tropical part Indian Ocean, mainly coastal regions and shallow waters of the marginal and inland seas of the northern and northeastern part of the ocean, as well as off the northeastern coast of Africa. At the same time, the tropical "oceanic desert" in the southern hemisphere stands out sharply for its minimum productivity.

Colonies are widespread in constantly warm waters coral polyps and coral structures of various types. On low-lying coasts and estuaries, they are ubiquitous mangrove thickets with their peculiar flora and fauna are very characteristic communities for the tidal zones of the Indian Ocean. Exceptionally rich plankton tropical ocean (unicellular algae, molluscs, jellyfish, some crustaceans) serves as food for fish(tuna, sharks) and sea reptiles (sea snakes, giant turtles, etc.).

Thanks to intensive vertical stirring waters, areas located in the temperate zone of the southern hemisphere are also rich in plankton, but with a slightly different species composition. Their fauna also includes some large mammals (pinnipeds, cetaceans), the number of which has greatly decreased over the long years of intensive fishing. At present, fishing in the Indian Ocean is much less developed than in others, and is mainly of a consumer nature, especially in coastal areas. Whaling in the southern Indian Ocean is almost terminated, the surviving species of whales - sperm whales and sei whales - have been taken under international protection.

The main source of widely used natural resources, the origin of which is associated with the history of the development of the northern part of the Indian Ocean, is the oil and gas basin of the Persian Gulf - one of the largest in the world.

• Pacific Ocean
• Indian Ocean
  • Ocean floor, mid-ocean ridges and transition zones
  • Features of the organic world
• Atlantic Ocean
  • Ocean Floor, Mid-Atlantic Ridge and Transition Zones
• Arctic Ocean
  • Ocean floor, mid-ocean ridges and transition zone

Look nature photography different continents and countries of the world (with geographical and biological semantic captions for photographs) can be found in the sections.

The presence of the Antarctic Circumpolar Current in the ocean determines the composition and distribution of organic life. Huge masses of ice limit life in the ocean, but nevertheless, the Antarctic seas in the abundance and diversity of living organisms can compete with many tropical regions of the World Ocean. The long existence of flora and fauna in a slightly changing environment (at least 5 million years) led to the fact that organisms have adapted to the harsh living conditions. Diatoms remain viable down to a temperature of -20 C. The fish have developed adaptations for life in supercooled water, and the inhabitants of the lower surface of the fast ice use the ice as a shelter, where rich pastures of fret algae - growths are formed.

The subpolar position of the Southern Ocean is associated with a sharp seasonal dynamics of the main condition of photosynthesis - solar radiation. Under such conditions, a large amplitude of quantitative changes in phytoplankton and a shift in the flowering zone from the north, where spring begins earlier, to the south, where it lags, is observed during the year. At low latitudes, two flowering peaks have time to develop, and at high latitudes only one. Biological latitudinal zoning is clearly expressed in surface waters. The inhabitants of the bottom do not have such zoning, since the bottom topography and barriers that impede the exchange of flora and fauna play an important role in their development. In the Southern Ocean, phytoplankton are dominated by diatoms (about 180 species). Blue-green algae are few in number. In quantitative terms, diatoms also predominate, especially in high latitudes, where there are almost 100% of them. During the period of maximum flowering, the abundance of diatoms reaches its largest concentration.

There is a clear relationship between the distribution of algae and the vertical stability of waters. In summer, a significant mass of algae is found in the 25-meter surface layer.

In the direction from south to north, the composition of phytoplankton changes: high-latitude cold-water species gradually drop out of the flora, being replaced by warm-water ones.

Zooplankton in the waters of the Southern Ocean is represented by copepods(about 120 types ), amphipods(about 80 species), etc., are less important chaetognaths, polychaetes, ostracods, appendiculars and molluscs... In quantitative terms, copepods are in first place, accounting for almost 75% of the zooplankton biomass of the Pacific and Indian sectors of the ocean. In the Atlantic sector of the ocean, there are few copepods, since euphausiids ( krill).

The Southern Ocean, especially its Antarctic regions, is characterized by a massive accumulation of krill (Antarctic crustaceans). The biomass of krill in these areas reaches 2,200 million tonnes, which makes it possible to catch up to 50-70 million tonnes of krill annually. Here krill are the main food of baleen whales, seals, fish, cephalopods, penguins and tube-nosed birds. Crustaceans feed on phytoplankton.

The abundance of zooplankton has two peaks throughout the year. The first is associated with the rise of overwintered species and is noted in surface waters. The second peak is characterized by the abundance of zooplankton throughout the entire thickness and is caused by the appearance of a new generation. Both peaks appear as two latitudinal zones of zooplankton concentration. This is the period of zooplankton bloom in the summer, when most of the zooplankton passes into the upper layers and moves to the north, where a significant accumulation occurs in the Antarctic convergence zone.

In winter, thickening is observed in the area of ​​divergence, where individuals from the deep water mass gather. In winter, the maximum species abundance was recorded at depths of 250-1000 m.

The question of the vertical distribution of zooplankton is complicated by the ability of many organisms to make regular (daily, seasonal) migrations from one zone to another.

The phytobenthos and zoobenthos in the waters of the Southern Ocean are striking in their richness and diversity. The number of phytobenthos decreases from South America to Antarctica. If on Tierra del Fuego there are 300 known species, in Kerguelen - 138, then off the coast of Antarctica there are from 20 to 40 species. Mostly different types of red algae prevail. Brown algae reach gigantic sizes (marcocystis - 80, and sometimes 90 m in length) with a limited biomass.

Among the representatives of zoobenthos, filter feeders prevail, mainly sponges (300 species), polychaetes (300), bryozoans (320), brachiopods (15), molluscs (300), echinoderms (320 species).

The biomass of zoobenthos in coastal areas averages up to 0.5 kg / m2, and in some places it reaches 3 kg / m2 at depths of 20-50 m in the surface zone there are no permanent inhabitants. Fauna is unevenly distributed along the coast. The decrease in biomass begins at a depth of 500 m.It should be noted that if in other areas of the World Ocean the lower boundary of the sublittoral is at a depth of 200 m, then near Antarctica, sublittoral animals live at depths of 500-700 m.The greatest species diversity is characteristic up to a depth of 200-300 m , fish - at depths of 200-500 m.

In the Antarctic region of the Southern Ocean, the fauna is rich, unique and has many endemics. The fauna is characterized by the gigantism of many representatives (for example, among sponges).

In the vicinity of Kurgelen Island, the fauna is 5 times poorer than the outlying areas. There are about 100 species of fish in the Southern Ocean. Among them, only 12 are benthic, belonging to the Notothenev family, which are of commercial importance. In the Antarctic sector, white-blooded pikes, grenadiers, gray and marble notothenia, and southern blue whiting are widely represented. In the Indian Ocean sector, the number of commercial fish is small. It is home to the striped white-blooded pike (ice fish), gray and marbled notothenia. In the Pacific sector, the largest in area, the southern blue whiting and New Zealand macrorunos are found.

Mammals. The total number of whales in the Southern Ocean is estimated at over 500,000. Pinnipeds include the crabeater seal, leopard seal, southern elephant seal, Ross seal, Weddell seal and a number of others. Antarctic seals account for up to 56% of the world's pinniped population.

Ornitafauna. It is represented by 44 species of birds with a total number of 200 million individuals. Among them, 7 species of penguins account for 90% of the total biomass.

The underwater world of the Indian Ocean is no less fascinating, diverse and vibrant than the nature of the coastal territories. Its warm waters are teeming with a large number of exotic plants and animals, which has made it possible to call the third largest ocean the most populated expanse of water.

In the waters of the Indian Ocean, among the incredibly beautiful coral structures, there is a huge number of brightly colored fish, sponges, molluscs, crustaceans, crabs, worms, sea stars, hedgehogs, turtles, glowing anchovies, sailfish.

There are also species dangerous to humans: octopuses, jellyfish, poisonous sea snakes and sharks. Large amounts of plankton are the main food for large fish such as sharks and tuna.

In the mangrove thickets, the spiny jumper lives - a fish that can stay on land for a long time due to its special body structure. Sardinella, mullet, horse mackerel, sea catfish are found in coastal waters. In the southern part, white-blooded fish live.

In tropical zones, you can find rare and unusual representatives of the siren genus - dugongs, and of course, dolphins and whales.

The most common birds are frigates and albatrosses. Among the endemic species are the paradise flycatcher and the shepherd partridge. Penguins live on the southern coast of Africa and Antarctica.

Vegetable world

The flora of the coastal zones of the Indian Ocean is represented by dense thickets of brown and red algae (fucus, kelp, macrocystis). Caulerpa is the most common green algae. Calcareous algae are lithotamnias and Halimeda, which together with corals form reefs. Of the higher plants, the most common thickets of posidonia - sea grass.