Features of the distribution of the organic world of the Indian Ocean. Organic world of the Indian Ocean

In the region of the Indonesian archipelago.

The position of most of the Indian Ocean in the strip from tropical to creates favorable climatic and hydrological conditions for the development of a diverse organic world here. The ocean as a whole is characterized by low bioproductivity - 35-40 kg/km2.

In the Indian Ocean, two biogeographic regions are distinguished - tropical and temperate. The tropical region is characterized by an exceptional abundance of plankton. Especially abundant is the "bloom" of the unicellular alga Trichodesmium, as a result of which the surface layer of water becomes cloudy and changes its color. Phytobenthos is represented by brown algae, sargassum, turbinaria, and caulerpa is abundant from green algae.

Of the higher plants, there are thickets of sea grass poseidonia. A special phytocenosis is formed in the coastal zones by mangroves typical of the Indian Ocean.

The zoobenthos is characterized by a variety of molluscs, calcareous and silicon sponges, echinoderms (sea urchin, brittle brittle, holothurian), numerous crustaceans, bryozoans, etc. Zoobenthos is especially rich on the shelves (500 g/m3). It includes many valuable commercial species (lobsters, shrimps). Accumulations of crustaceans border the shores,. Of the shellfish in these areas, there are many cuttlefish and squid.

The ichthyofauna of the ocean is rich and varied. The shelf zone is inhabited by sardinella, mackerel, anchovy, horse mackerel, reef and rock perch. In the open waters of the ocean, there is an abundance of tuna, dolphins, which are of great commercial importance.

In tropical waters, there are many sharks, giant sea turtles, sea snakes and flying fish, swordfish are found. The tropical zone of the Indian Ocean is one of the areas of classical development of coral polyps and reef structures.

The temperate region is characterized by red and brown algae, mainly from the Fucus and Laminaria groups.

In temperate waters, cetaceans are widely represented: toothless and blue whales, as well as seals, elephant seals, and dugongs. The richness of cetaceans in these latitudes is explained by the intense vertical mixing of waters, which creates exceptionally favorable conditions for the development of planktonic organisms, which are the main food of the blue and toothless whales. In the same waters, notothenia and white-blooded fish live, forming large commercial concentrations.

In the waters of the Indian Ocean, there are many organisms that glow at night: ctenophores, some types of jellyfish, peridine. Brightly colored siphonophores, including poisonous physalia, were widely developed. There are also many foraminifers, and an abundance of pteropods in the waters. As in other oceans, organic life is extremely unevenly distributed in the Indian Ocean. First of all, it is necessary to note the high productivity of coastal waters, primarily in the Red, Arabian Seas, Persian, Aden and Bengal bays, where the primary production is 250-500 mg/m2. Tropical "oceanic" stands out sharply in the Southern Hemisphere and the central regions of the Arabian and Bengal bays, characterized by a primary production of 35-100 mg / m2. As in the Pacific Ocean, the value of primary production increases sharply in water areas adjacent to oceanic ones. Its values are especially high on coral reefs.

Data on primary production and a general estimate of biomass in the Indian Ocean indicate that it is no poorer than in the Pacific and. However, the annual global catch of fish in the Indian Ocean is 9 million tons, which indicates that its fish resources are still poorly used. In the open waters of the tropical zones of the Indian Ocean, there is only one type of commercial fishing - tuna fishing. According to estimates, the catch of fish without undermining the base of renewal can reach 10-14 million tons per year. Consequently, the Indian Ocean can be considered as a significant reserve for the world's marine fisheries.

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

Climate. There are 4 climatic conditions in the region. belts. Influenced by Asians. continent in the north. parts of Ind. ocean, a monsoon climate is established with frequent cyclones moving towards the coasts. High atm. pressure over Asia in winter causes north-east formation. monsoon. In summer, it is replaced by a humid south-west. monsoon, carrying air from the southern regions of the ocean. During the summer monsoon, there is often a wind force of over 7.0. Summer temp. over the ocean = 28-32 °C, in winter 18-22 °C. In the south tropics sir. southeast trade wind, cat. in winter. time does not extend north of 10°N. Wed
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year. temp.= 25 °C. In the zone 40-45°S. throughout the year - app. air transfer. wt. In zap. part of the ocean, hurricanes occur (up to 8 times a year), in the districts of Madagascar and the Mascarene Islands. In subtropics. 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 characteristic from 45 degrees and south. In winter, the temperature here ranges from -16 °C to 6 °C, and in summer - from -4 °C to 10 °C. Max. amount of precipitation (2.5 thousand mm) - to the east. equator region.
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zones. The smallest amount of precipitation is observed in the trails. district south. hemisphere.

hydrological regime. Winter: Southwest. monsoon. tech-e, beginning. in the Bay of Bengal. South of 10°N this current moves to the West. tech. Then it branches: 1 branch goes to the sowing. to the Red Sea, 2- south to 10°S. 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 the powerful Somali current, which is joined by the current from the Red Sea in the Gulf of Aden. In the Bay of Bengal, the summer monsoon current splits to the north.
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and south., ĸᴏᴛᴏᴩᴏᴇ merges into south. Passat flow. South Passat. tech-e crosses the ocean from the east. on the app. to Madagascar. At Madagascar South. Passat. the current branches, giving rise to the Equatorial countercurrent, Mozambique and Madagascar currents. Merging southwest of Madagascar, they form the warm Agulhas Current. South part of this flow goes to the Atlantic. ocean, and part flows into the tech-e West. winds. On the approach to Australia, the cold moves north from the latter. West Australian Current.

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

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. Reduced salinity (less than 34 ‰) is characteristic of subarctic waters, where the strong freshening effect of melted glacial waters is felt.

Flora and fauna Ind. OK. extraordinarily varied. tropical the area stands out for its abundance of plankton. The unicellular alga Trichodesmium (a type of Cyanobacterium) 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 that glow at night: peridynes, some types of jellyfish, ctenophores, and tunicates. Brightly colored siphonophores are abundant, incl. poisonous phasalians. In temperate and arctic waters, the main representatives of plankton are copepods, euphuazids, and diatoms. The most numerous fish of the Indian Ocean are dolphins, tuna, notothenia and various sharks. From reptiles there are several species of giant sea turtles, sea snakes, from mammals - cetaceans (toothless and blue whales, sperm whales, dolphins), seals, sea elephants. Most cetaceans live in temperate and polar regions, where, due to the intensive mixing of waters, favorable conditions arise for the development of planktonic organisms. Birds are represented by albatrosses and frigates, as well as several species of penguins that inhabit the coasts of South Africa, Antarctica and the islands that lie in the temperate ocean.

Flora Indus. ocean is represented by brown (sargassum, turbinaria) and green algae (caulerna). The calcareous algae of lithotamnia and chalimed also flourish, which, together with corals, participate in the construction of reef structures. In the process of 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 the phytocenosis formed by mangroves. Such thickets are especially characteristic of river mouths and occupy large areas in Southeast Africa, Western Madagascar, Southeast Asia and other areas. For temperate and Antarctic waters, the most characteristic are red and brown algae, mainly from the groups of fucus and kelp, porphyry, and helidium. In the subpolar regions of the southern hemisphere, giant macrocystis are found.

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

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.

Introduction

1.History of the formation and exploration of the Indian Ocean

2.General information about the Indian Ocean

Bottom relief.

.Characteristics of the waters of the Indian Ocean.

.Bottom sediments of the Indian Ocean and its structure

.Minerals

.Climate of the Indian Ocean

.Flora and fauna

.Fishing and marine industry

Introduction

Indian Ocean- the youngest and warmest among the world's oceans. Most of it is in the southern hemisphere, and in the north it goes far into the mainland, which is why ancient people considered it just a big sea. It was here, in the Indian Ocean, that man began his first sea voyages.

The largest rivers of Asia belong to the Indian Ocean basin: the Salween, the Irrawaddy and the Ganges with the Brahmaputra, which flow into the Bay of Bengal; the Indus, which flows into the Arabian Sea; Tigris and Euphrates, merging a little above the confluence with the Persian Gulf. Of the major rivers of Africa, which also flow into the Indian Ocean, the Zambezi and Limpopo should be mentioned. Because of them, the water off the coast of the ocean is muddy, with a high content of sedimentary rocks - sand, silt and clay. But the open waters of the ocean are amazingly clear. The tropical islands of the Indian Ocean are famous for their cleanliness. A variety of animals have found their place on coral reefs. The Indian Ocean is home to the famous sea devils, rare whale sharks, bigmouths, sea cows, sea snakes, etc.

1. History of formation and research

Indian Oceanformed at the junction of the Jurassic and Cretaceous periods as a result of the collapse of Gondwana (130-150 million years ago). Then there was a separation of Africa and the Deccan from Australia with Antarctica, and later - Australia from Antarctica (in the Paleogene, about 50 million years ago).

The Indian Ocean and its shores remain poorly explored. The name of the Indian Ocean is found already at the beginning of the 16th century. Schöner under the name Oceanus orientalis indicus, in contrast to the Atlantic Ocean, then known as Oceanus occidentalis. Subsequent geographers called the Indian Ocean mostly the Sea of India, some (Varenius) the Australian Ocean, and Fleurie recommended (in the 18th century) to call it even the Great Indian Gulf, considering it as part of the Pacific Ocean.

In ancient times (3000-1000 BC), sailors from India, Egypt and Phoenicia traveled across the northern part of the Indian Ocean. The first navigation charts were compiled by the ancient Arabs. At the end of the 15th century, the first European, the famous Portuguese Vasco da Gama, circled Africa from the south and entered the waters of the Indian Ocean. By the 16th-17th centuries, Europeans (the Portuguese, and later the Dutch, French and British) increasingly appeared in the Indian Ocean basin, and by the middle of the 19th century, most of its coasts and islands were already the property of Great Britain.

Discovery historycan be divided into 3 periods: from ancient voyages to 1772; from 1772 to 1873 and from 1873 to the present. The first period is characterized by the study of the distribution of ocean and land waters in this part of the globe. It began with the first voyages of Indian, Egyptian and Phoenician navigators, who, in 3000-1000 BC. traveled through the northern part of the Indian Ocean, and ended with the voyage of J. Cook, who in 1772-75 penetrated south to 71 ° S. sh.

The second period was marked by the beginning of deep-sea research, first conducted by Cook in 1772 and continued by Russian and foreign expeditions. The main Russian expeditions were - O. Kotzebue on the "Rurik" (1818) and Pallen on the "Cyclone" (1858-59).

The third period is characterized by complex oceanographic research. Until 1960 they were carried out on separate ships. The largest work was carried out by expeditions on the ships Challenger (English) in 1873-74, Vityaz (Russian) in 1886, Valdivia (German) in 1898-99 and Gauss (German) in 1901-03, "Discovery II" (English) in 1930-51, the Soviet expedition to the "Ob" in 1956-58, etc. In 1960-65, the Intergovernmental Oceanographic Expedition under UNESCO conducted an international Indian Ocean Expedition, which collected new valuable data on hydrology, hydrochemistry, meteorology , geology, geophysics and biology of the Indian Ocean.

. General information

Indian Ocean- the third largest ocean of the Earth (after the Pacific and Atlantic), covering about 20% of its water surface. Almost all of it is in the southern hemisphere. Its area is 74917 thousand km ² ; average volume of water - 291945 thousand km ³. In the north it is bounded by Asia, in the west by the Arabian Peninsula and Africa, in the east by Indochina, the Sunda Islands and Australia, in the south by the Southern Ocean. The border between the Indian and Atlantic Oceans runs along the 20° meridian of east longitude. (Meridian of the Cape of Needles), between the Indian and Pacific Oceans runs along the 147 ° meridian of east longitude (meridian of the southern cape of the island of Tasmania). The northernmost point of the Indian Ocean is located at approximately 30° north latitude in the Persian Gulf. The width of the Indian Ocean is approximately 10,000 km between the southern points of Australia and Africa.

The greatest depth of the Indian Ocean is the Sunda, or Java Trench (7729 m), the average depth is 3700 m.

The Indian Ocean washes three continents at once: Africa from the east, Asia from the south, Australia from the north and northwest.

The Indian Ocean has the fewest seas compared to other oceans. The largest seas are located in the northern part: the Mediterranean - the Red Sea and the Persian Gulf, the semi-enclosed Andaman Sea and the marginal Arabian Sea; in the eastern part - the Arafura and Timor seas.

In the Indian Ocean, there are the island states of Madagascar (the fourth largest island in the world), Sri Lanka, the Maldives, Mauritius, the Comoros, and the Seychelles. The ocean washes in the east such states: Australia, Indonesia; in the northeast: Malaysia, Thailand, Myanmar; in the north: Bangladesh, India, Pakistan; in the west: Oman, Somalia, Kenya, Tanzania, Mozambique, South Africa. In the south it borders on Antarctica. There are relatively few islands. In the open part of the ocean, there are volcanic islands - Mascarene, Crozet, Prince Edward, etc. In tropical latitudes, coral islands rise on volcanic cones - Maldives, Laccadive, Chagos, Cocos, most of the Andaman, etc.

. Bottom relief

The ocean floor is a system of mid-ocean ridges and basins. In the region of Rodrigues Island (Mascarene Archipelago) there is a so-called triple junction, where the Central Indian and West Indian ridges converge, as well as the Australo-Antarctic Rise. The ridges consist of steep mountain ranges, cut by normal or oblique faults with respect to the axes of the chains, and divide the basalt ocean floor into 3 segments, and their tops are, as a rule, extinct volcanoes. The bottom of the Indian Ocean is covered with deposits of the Cretaceous and later periods, the thickness of which varies from several hundred meters to 2-3 km. The deepest of the numerous trenches of the ocean is the Yavan (4,500 km long and 29 km wide). The rivers flowing into the Indian Ocean carry with them huge amounts of sedimentary material, especially from the territory of India, creating high alluvial rapids.

The coast of the Indian Ocean is replete with cliffs, deltas, atolls, coastal coral reefs and salt marshes overgrown with mangroves. Some islands - for example, Madagascar, Socotra, Maldives - are fragments of ancient continents. Numerous islands and archipelagos of volcanic origin are scattered in the open part of the Indian Ocean. In the northern part of the ocean, many of them are crowned with coral structures. Andaman, Nicobar or Christmas Island - are of volcanic origin. The Kerguelen Plateau, located in the southern part of the ocean, also has a volcanic origin.

An underwater earthquake in the Indian Ocean on December 26, 2004 triggered a tsunami that has been recognized as the deadliest natural disaster in modern history. The magnitude of the earthquake was, according to various estimates, from 9.1 to 9.3. This is the second or third strongest earthquake on record.

The epicenter of the earthquake was located in the Indian Ocean, north of the island of Simeulue, located near the northwestern coast of the island of Sumatra (Indonesia). The tsunami reached the shores of Indonesia, Sri Lanka, southern India, Thailand and other countries. The height of the waves exceeded 15 meters. The tsunami caused enormous destruction and a huge number of deaths, even in Port Elizabeth, South Africa, 6900 km from the epicenter. Died, according to various estimates, from 225 thousand to 300 thousand people. The true death toll is unlikely to ever be known, as many people were swept into the sea by the water.

With regard to the properties of the bottom soil, then, like in other oceans, sediments on the bottom of the Indian Ocean can be divided into three classes: coastal sediments, organic silt (globigerine, radiolar or diatom) and special clay of great depths, the so-called red clay. Coastal sediments are sand, located mostly on coastal shallows to a depth of 200 meters, green or blue silt near rocky coasts, brown in volcanic areas, but lighter and sometimes pinkish or yellowish near coral coasts due to the lime prevailing here. Globigerin silt, consisting of microscopic foraminifers, covers the deeper parts of the ocean floor almost to a depth of 4500 m; south of parallel 50°S sh. calcareous foraminiferal deposits disappear and are replaced by microscopic siliceous, from the group of algae, diatoms. With regard to the accumulation of diatom remains on the bottom, the southern part of the Indian Ocean is especially different from other oceans, where diatoms are found only in places. Red clay occurs at depths greater than 4500 m; it has the color red, or brown, or chocolate.

indian ocean climate fossil fishery

4. Characteristics of waters

Surface water circulationin the northern part of the Indian Ocean it has a monsoonal character: in summer - northeast and east currents, in winter - southwest and west currents. During the winter months between 3° and 8° S. sh. an inter-trade (equatorial) countercurrent develops. In the southern part of the Indian Ocean, water circulation forms an anticyclonic circulation, which is formed from warm currents - the South Trade Wind in the North, Madagascar and Needle in the West and cold ones - the West Winds in the South and West Australian in the East South of 55 ° S. sh. several weak cyclonic water cycles develop, closing off the coast of Antarctica with an easterly current.

Belt of the Indian Oceanbetween 10 ° With. sh. and 10 ° Yu. sh. called the thermal equator, where the surface water temperature is 28-29°C. To the south of this zone, the temperature drops, reaching ?1°C off the coast of Antarctica. In January and February, the ice along the coast of this continent melts, huge blocks of ice break off from the ice sheet of Antarctica and drift towards the open ocean. To the north, the temperature characteristics of the waters are determined by the monsoon air circulation. In summer, temperature anomalies are observed here, when the Somali current cools surface waters to a temperature of 21-23°C. In the eastern part of the ocean at the same geographical latitude, the water temperature is 28 ° C, and the highest temperature mark - about 30 ° C - was recorded in the Persian Gulf and the Red Sea. The average salinity of ocean waters is 34.8‰. The most salty waters are the Persian Gulf, the Red and Arabian Seas: this is due to intensive evaporation with a small amount of fresh water brought into the seas by rivers.

The tides in the Indian Ocean, as a rule, are small (off the coast of the open ocean and on the islands from 0.5 to 1.6 m), only at the tops of some bays they reach 5-7 m; in the Gulf of Cambay 11.9 m. The tides are predominantly semi-diurnal.

Ice forms at high latitudes and is carried by winds and currents along with icebergs in a northerly direction (up to 55 ° S in August and up to 65-68 S in February).

. Bottom sediments of the Indian Ocean and its structure

Bottom sedimentsthe Indian Ocean have the greatest thickness (up to 3-4 km) at the foot of the continental slopes; in the middle of the ocean - small (about 100 m) thickness and in places where the dissected relief is distributed - discontinuous distribution. The most widely represented are foraminiferal (on continental slopes, ridges, and at the bottom of most basins at depths up to 4700 m), diatoms (south of 50° S), radiolarian (near the equator), and coral sediments. Polygenic sediments - red deep-sea clays - are distributed south of the equator at a depth of 4.5-6 km or more. Terrigenous sediments - off the coast of the continents. Chemogenic sediments are mainly represented by ferromanganese nodules, while riftogenic sediments are represented by destruction products of deep rocks. Outcrops of bedrocks are most often found on continental slopes (sedimentary and metamorphic rocks), mountains (basalts) and mid-ocean ridges, where, in addition to basalts, serpentinites and peridotites have been found, representing a slightly altered substance of the Earth's upper mantle.

The Indian Ocean is characterized by the predominance of stable tectonic structures both on the bed (thalassocratons) and along the periphery (continental platforms); active developing structures - modern geosynclines (Sonda arc) and georiftogenals (mid-ocean ridge) - occupy smaller areas and continue in the corresponding structures of Indochina and rifts of East Africa. These main macrostructures, which differ sharply in morphology, the structure of the earth's crust, seismic activity, and volcanism, are subdivided into smaller structures: plates, usually corresponding to the bottom of oceanic basins, blocky ridges, volcanic ridges, sometimes topped with coral islands and banks (Chagos, Maldives, etc.). .), trench-faults (Chagos, Ob, etc.), often confined to the foot of blocky ridges (East Indian, West Australian, Maldives, etc.), fault zones, tectonic ledges. Among the structures of the Indian Ocean bed, a special place (according to the presence of continental rocks - granites of the Seychelles and the continental type of the earth's crust) is occupied by the northern part of the Mascarene Range - a structure that is apparently part of the ancient Gondwana mainland.

. Minerals

The most important minerals of the Indian Ocean are oil and natural gas. Their deposits are found on the shelves of the Persian and Suez Gulfs, in the Bass Strait, on the shelf of the Hindustan Peninsula. In terms of reserves and production of these minerals, the Indian Ocean ranks first in the world. On the coasts of Mozambique, the islands of Madagascar and Ceylon, ilmenite, monazite, rutile, titanite and zirconium are exploited. Off the coast of India and Australia there are deposits of barite and phosphorite, and in the shelf zones of Indonesia, Thailand and Malaysia, deposits of cassiterite and ilmenite are exploited on an industrial scale. On the shelves - oil and gas (especially the Persian Gulf), monazite sands (the coastal region of Southwestern India), etc.; in reef zones - ores of chromium, iron, manganese, copper, etc.; on the bed - huge accumulations of ferromanganese nodules.

. Climateindian ocean

Most of the Indian Ocean is located in warm climatic zones - equatorial, subequatorial and tropical. Only its southern regions, located at high latitudes, are strongly influenced by Antarctica. The equatorial climate zone of the Indian Ocean is characterized by a constant predominance of humid warm equatorial air. Average monthly temperatures range here from 27° to 29°. The water temperature is slightly higher than the air temperature, which creates favorable conditions for convection and precipitation. Their annual amount is large - up to 3000 mm and more.

. Flora and fauna

The most dangerous mollusks in the world live in the Indian Ocean - cone snails. Inside the snail there is a rod-like container with poison, which it injects into its prey (fish, worms), its poison is also dangerous for humans.

The entire water area of the Indian Ocean lies within the tropical and southern temperate zones. The shallow waters of the tropical zone are characterized by numerous 6- and 8-ray corals, hydrocorals, capable of creating islands and atolls together with calcareous red algae. The richest fauna of various invertebrates (sponges, worms, crabs, mollusks, sea urchins, brittle stars and starfish), small but brightly colored coral fish live among the powerful coral structures. Most of the coasts are occupied by mangroves, in which the mud jumper stands out - a fish that can exist in the air for a long time. The fauna and flora of the beaches and rocks that dry out at low tide are quantitatively depleted as a result of the depressing effect of the sun's rays. In the temperate zone, life on such stretches of coasts is much richer; dense thickets of red and brown algae (kelp, fucus, reaching the huge size of microcystis) develop here, various invertebrates are abundant. For the open spaces of the Indian Ocean, especially for the surface layer of the water column (up to 100 m), rich flora is also characteristic. Of the unicellular planktonic algae, several species of peredinium and diatom algae predominate, and in the Arabian Sea - blue-green algae, which often cause the so-called water bloom during mass development.

The bulk of the ocean's animals are copepods (more than 100 species), followed by pteropods, jellyfish, siphonophores, and other invertebrates. Of the unicellular, radiolarians are characteristic; numerous squids. Of the fish, the most abundant are several species of flying fish, luminous anchovies - myctophids, dolphins, large and small tuna, sailfish and various sharks, poisonous sea snakes. Sea turtles and large marine mammals (dugongs, toothed and toothless whales, pinnipeds) are common. Among the birds, the most characteristic are albatrosses and frigates, as well as several species of penguins that inhabit the coasts of South Africa, Antarctica and the islands that lie in the temperate zone of the ocean.

At night, the surface of the Indian Ocean shimmers with lights. Light is produced by small marine plants called dinoflagellates. Luminous areas sometimes have the shape of a wheel with a diameter of 1.5 m.

. Fishing and marine industry

Fishing is underdeveloped (the catch does not exceed 5% of the world catch) and is limited to the local coastal zone. Near the equator (Japan) is fishing for tuna, and in Antarctic waters - whale fishing. In Sri Lanka, on the Bahrain Islands and on the northwestern coast of Australia, pearls and mother-of-pearl are mined.

The countries of the Indian Ocean also have significant resources of other valuable types of mineral raw materials (tin, iron and manganese ores, natural gas, diamonds, phosphorites, etc.).

Bibliography:

1.Encyclopedia "Science" Dorling Kindersley.

.“I know the world. Geography” V.A. Markin

3.slovari.yandex.ru ~ TSB books / Indian Ocean /

4.Big Encyclopedic Dictionary of Brockhaus F.A., Efron I.A.

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Physical geography of continents and oceans

OCEANS

INDIAN OCEAN

Features of the organic world of the Indian Ocean

The fauna and flora of the Indian Ocean have resemblance 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).

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

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

Thanks to intensive vertical mixing water 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), whose numbers have been greatly reduced over many years of intensive fishing. Currently, fisheries in the Indian Ocean are much less developed than in others, and are mainly of a consumer nature, especially in coastal areas. Whaling in the southern Indian Ocean is practically discontinued, preserved species of whales - sperm whales and sei whales - are taken under international protection.

The main source of widely used natural resources, whose origin 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

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Physical geography of continents and oceans

OCEANS

INDIAN OCEAN

Features of the organic world of the Indian Ocean

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 various continents and countries of the world (with geographical and biological semantic captions for photographs) can be in sections.