Organic world of the Atlantic Ocean. biological resources
Human economic activity has led to severe pollution of some areas of the Pacific Ocean. This was especially evident off the coast of Japan and North America. The stocks of whales, a number of valuable species of fish and other animals have been depleted. Some of them have lost their former commercial value.
§ 8. Atlantic Ocean
Geographical position. The Atlantic Ocean stretches from north to south for 16 thousand km from subarctic to antarctic latitudes. The ocean is wide in the northern and southern parts, narrows in equatorial latitudes up to 2900 km. In the north it communicates with the Arctic Ocean, and in the south it is widely connected with the Pacific and Indian Oceans. It is bounded by the shores of North and South America - in the west, Europe and Africa - in the east and Antarctica - in the south.
The Atlantic Ocean is the second largest ocean in the world. The coastline of the ocean in the northern hemisphere is heavily dissected by numerous peninsulas and bays. Near the continents there are many islands, inland and marginal seas. The Atlantic consists of 13 seas, which occupy 11% of its area.
Bottom relief. Through the entire ocean (approximately at an equal distance from the coasts of the continents) passes Mid-Atlantic Ridge. The relative height of the ridge is about 2 km. Transverse faults divide it into separate segments. In the axial part of the ridge there is a giant rift valley 6 to 30 km wide and up to 2 km deep. Both underwater active volcanoes and volcanoes of Iceland and the Azores are confined to the rift and faults of the Mid-Atlantic Ridge. On both sides of the ridge there are basins with a relatively flat bottom, separated by elevated uplifts. The shelf area in the Atlantic Ocean is larger than in the Pacific.
Mineral resources. Oil and gas reserves have been discovered on the shelf of the North Sea, in the Gulf of Mexico, Guinea and Biscay. Phosphorite deposits have been discovered in the area of deep water rise off the coast of North Africa in tropical latitudes. Placer deposits of tin off the coast of Great Britain and Florida, as well as diamond deposits off the coast of South-West Africa, have been found on the shelf in the sediments of ancient and modern rivers. Ferromanganese nodules have been found in bottom basins off the coasts of Florida and Newfoundland.
Climate. The Atlantic Ocean is located in all climatic zones Earth. The main part of the ocean area is between 40°N. and 42° S - is located in subtropical, tropical, subequatorial and equatorial climatic zones. There are high positive air temperatures all year round. The most severe climate is in the subantarctic and antarctic latitudes, and to a lesser extent in the subpolar, northern latitudes.
currents. In the Atlantic, as in the Pacific Ocean, two rings of surface currents are formed.. In the northern hemisphere, the North Equatorial Current, the Gulf Stream, the North Atlantic and Canary Currents form the movement of waters in a clockwise direction. In the southern hemisphere, the South Equatorial, Brazilian, Current Western winds and Benguela form the movement of the waters counterclockwise. Due to the significant length of the Atlantic Ocean from north to south, meridional water flows are more developed in it than latitudinal ones.
Water properties. Zoning water masses in the ocean is complicated by the influence of land and sea currents. This is manifested primarily in the temperature distribution surface water. In many areas of the ocean, the isotherms near the coast deviate sharply from the latitudinal direction.
The northern half of the ocean is warmer than the southern, the temperature difference reaches 6°C. The average surface water temperature (16.5°C) is slightly lower than in the Pacific Ocean. The cooling effect is exerted by the waters and ices of the Arctic and Antarctic. Salinity of surface waters in the Atlantic Ocean is high. One of the reasons for increased salinity is that a significant part of the moisture evaporating from the water area does not return to the ocean again, but is transferred to neighboring continents (due to the relative narrowness of the ocean).
Many large rivers flow into the Atlantic Ocean and its seas: the Amazon, Congo, Mississippi, Nile, Danube, La Plata, etc. They carry huge masses of fresh water, suspended material and pollutants into the ocean. In desalinated bays and seas of subpolar and temperate latitudes, ice forms near the western shores of the ocean in winter. Numerous icebergs and floating sea ice hinder navigation in the North Atlantic Ocean.
organic world . The Atlantic Ocean is poorer in species in the composition of flora and fauna than the Pacific. One of the reasons for this is its relative geological youth and a noticeable cooling in the Quaternary period during the glaciation of the northern hemisphere. However, in quantitative terms, the ocean is rich in organisms - it is the most productive per unit area.. This is primarily due to the wide development of shelves and shallow banks, which are inhabited by many demersal and bottom fish (cod, flounder, perch, etc.). The biological resources of the Atlantic Ocean are depleted in many areas. The share of the ocean in world fisheries for last years decreased significantly.
natural complexes. In the Atlantic Ocean, all zonal complexes are distinguished - natural belts, except for the north polar. Water northern subpolar belt rich in life. It is especially developed on the shelves off the coasts of Iceland, Greenland and the Labrador Peninsula. Temperate zone characterized by intense interaction of cold and warm waters, its waters are the most productive areas of the Atlantic. Vast expanses of warm waters subtropical, two tropical and equatorial belts less productive than the waters of the northern temperate zone.
In the northern subtropical zone stands out a special natural aquatic complex of the Sargasso Sea. It is characterized by high water salinity (up to 37.5 ppm) and low bioproductivity. In clear water, pure of blue color are growing brown algae - sargasso, which gave the name of the water area.
In the temperate zone of the southern hemisphere, as in the north, natural complexes are rich in life in areas where waters with different temperatures and water densities mix. In the subantarctic and antarctic belts the manifestation of seasonal and permanent ice phenomena, which are reflected in the composition of the fauna (krill, cetaceans, notothenia fish), is characteristic.
Economic use. All types of human economic activity in marine areas are represented in the Atlantic Ocean. Among them highest value have maritime transport, then - underwater oil and gas production, only then - the catch and use of biological resources.
More than 70 coastal countries with a population of over 1.3 billion people are located on the shores of the Atlantic. Many transoceanic routes pass through the ocean with large volumes of freight and passenger traffic. On the coasts of the ocean and its seas, the most significant ports of the world in terms of cargo turnover are located.
The already explored mineral resources of the ocean are significant (examples are given above). However, oil and gas fields on the shelf of the Northern and caribbean, in the Bay of Biscay. Many countries that previously did not have significant reserves of these types of mineral raw materials are now experiencing an economic upswing due to their extraction (England, Norway, the Netherlands, Mexico, etc.).
biological resources oceans have long been intensively used. However, due to the overfishing of a number of valuable commercial fish species, in recent years the Atlantic has yielded to the Pacific Ocean in terms of fish and seafood.
Intensive human economic activity in the waters of the Atlantic Ocean and its seas causes a noticeable deterioration natural environment- both in the ocean (pollution of water, air, decrease in stocks of commercial fish species), and on the coasts. In particular, recreational conditions on the ocean coast are deteriorating. In order to prevent further and reduce the existing pollution of the natural environment of the Atlantic Ocean, scientific recommendations are being developed and international agreements are being concluded on rational use ocean resources.
§ 9. Indian Ocean
Geographical position. The Indian Ocean is located entirely in the Eastern Hemisphere between Africa - in the west, Eurasia - in the north, the Sunda Islands and Australia - in the east, Antarctica - in the south. The Indian Ocean in the southwest communicates widely with the Atlantic Ocean, and in the southeast with the Pacific. The coastline is poorly dissected. There are eight seas in the ocean, there are large bays. There are relatively few islands. The largest of them are concentrated near the coasts of the continents.
Bottom relief. As in other oceans, the bottom topography in the Indian Ocean is complex and varied. Among the uplifts at the bottom of the ocean stands out mid-ocean ridge system diverging to the northwest and southeast. The ridges are characterized by rifts and transverse faults, seismicity and underwater volcanism. Between the ridges lie numerous deep sea basins. The shelf generally has a small width. But it is significant off the coast of Asia.
Mineral resources. There are significant oil and gas deposits in the Persian Gulf, off the coast of Western India and off the coast of Australia. Large reserves of ferromanganese nodules have been found at the bottom of many basins. Sedimentary rock deposits on the shelf contain tin ores, phosphorites, and gold.
Climate. The main part of the Indian Ocean lies in the equatorial, subequatorial and tropical zones., only the southern part covers high latitudes, up to the subantarctic. main feature ocean climate - seasonal monsoon winds in its northern part, which is heavily influenced by land. Therefore, in the northern part of the ocean there are two seasons of the year - a warm, quiet, sunny winter and a hot, cloudy, rainy, stormy summer. South of 10°S dominated by the southeast trade wind. To the south, in temperate latitudes, a strong and steady westerly wind blows. The amount of precipitation is significant in the equatorial zone - up to 3000 mm per year. There is very little precipitation off the coast of Arabia, in the Red Sea and the Persian Gulf.
currents. In the northern part of the ocean, the formation of currents is influenced by the change of monsoons, which rebuilds the system of currents according to the seasons of the year: summer monsoon - in the direction from west to east, winter - from east to west. In the southern part of the ocean, the most significant are the South Equatorial Current and the Western Wind Current.
Water properties. The average surface water temperature is +17°С. Somewhat lower average temperature due to the strong cooling effect of Antarctic waters. The northern part of the ocean warms up well, is deprived of the influx of cold waters and is therefore the warmest. In summer, the water temperature in the Persian Gulf rises to +34°C. In the southern hemisphere, the temperature of the waters gradually decreases with increasing latitude. The salinity of surface waters in many areas is higher than average, and in the Red Sea it is especially high (up to 42 ppm).
organic world. Has much in common with Pacific Ocean. The species composition of fish is rich and varied. Sardinella, anchovy, mackerel, tuna, dolphin, sharks, flying fish live in the northern part of the Indian Ocean. In southern waters - notothenia and white-blooded fish; there are cetaceans and pinnipeds. especially rich organic world shelf and coral reefs. Seagrass beds fringe the shores of Australia, South Africa, islands. There are large commercial accumulations of crustaceans (lobsters, shrimps, krill, etc.). Generally biological resources The Indian Ocean is still poorly explored and underused.
natural complexes. The northern part of the ocean lies in tropical zone. Under the influence of the surrounding land and monsoon circulation, several aquatic complexes are formed in this belt, differing in the properties of water masses. Especially sharp differences are noted in the salinity of the waters.
In the equatorial zone The temperature of surface waters hardly changes with the seasons of the year. Above the numerous uplifts of the bottom and near the coral islands in this belt, a lot of plankton develops, and bioproductivity increases. Tunas live in such waters.
Zonal complexes of the southern hemisphere V in general terms similar in natural conditions to similar belts of the Pacific and Atlantic oceans.
Economic use. The biological resources of the Indian Ocean have been used by the inhabitants of the coasts since time immemorial. And until now, handicrafts of fish and other seafood retain an important role in the economy of many countries. However Natural resources oceans are used to a lesser extent than in other oceans. Biological productivity of the ocean as a whole is low, it increases only on the shelf and the continental slope.
Chemical resources ocean waters are still poorly used. On a large scale, desalination of salt water is being carried out in the countries of the Middle East, where there is an acute shortage of fresh water.
Among mineral resources oil and gas deposits are identified. In terms of their reserves and production, the Indian Ocean ranks first in the World Ocean. Coastal-marine placers contain heavy minerals and metals.
Important transport routes pass through the Indian Ocean. In the development of shipping, this ocean is inferior to the Atlantic and Pacific, but in terms of oil transportation it surpasses them. The Persian Gulf is the main oil export region of the world, from here a large cargo flow of oil and oil products begins. Therefore, in this area, systematic monitoring of the state is necessary. aquatic environment and protecting it from oil pollution.
§ 10. Arctic Ocean
Geographical position. The ocean is located in the center of the Arctic, surrounded by land on almost all sides, which determines the features of its nature - climate, hydrological conditions, ice conditions. The Arctic Ocean is the smallest of the Earth's oceans.
The boundaries of the ocean run from the Scandinavian Peninsula (62 ° N), to the Shetland and Faroe Islands, along the Danish and Davis Straits, as well as the Bering Strait, through which its waters communicate with the waters of the Atlantic and Pacific Oceans.
The coastline is heavily indented. There are nine seas in the ocean, which account for half of the entire ocean area. The largest sea is Norwegian, the smallest is White. Many island archipelagos and single islands.
Bottom relief. About half of the area of the ocean floor is occupied by the shelf. The shelf strip off the coast of Eurasia is especially wide, where it is measured in many hundreds of kilometers. The ocean bed consists of several basins separated by underwater ridges. The main element of the bottom topography is the Gakkel Ridge. It is a continuation of the Mid-Atlantic Ridge. The Lomonosov, Mendeleev, and Chukchi uplifts are also distinguished.
Mineral resources. The bottom sediments of the shelf zone are formed by sediments from rivers. Placer deposits of heavy metals (tin, etc.) were found in them. In addition, more than 50 oil and gas fields have been discovered on the ocean shelf; some of them are already under development.
Climate. Climate features are determined by the polar position of the ocean. Arctic air masses form and dominate over its water area throughout the year.. The average air temperature in winter drops to -40°С, in summer it is close to 0°. During the polar day, ice reflects a significant part of solar radiation, increasing the severity of the climate. Precipitation over the ocean falls from 100 to 200 mm per year.
currents. A powerful stream of warm water enters the Arctic Ocean from the North Atlantic - branches of the North Atlantic Current. As you move east and north, the relatively more saline and denser waters of the Atlantic sink under the less saline, though cold, waters of the Arctic Ocean. From the Chukchi and East Siberian seas, the waters in the ocean move in the opposite direction - from east to west. This is how it is formed Transarctic Current, which carries polar waters and ice into the Atlantic, mainly through the Denmark Strait.
Water properties. Ice . Preservation of the existing hydrological regime and life in the Arctic Ocean is possible only under the condition of water and heat exchange with neighboring oceans. The heat reserves in the water masses of the ocean are constantly maintained due to the influx of warm waters from the Atlantic Ocean. In addition, a large river flow from the territory of Eurasia and North America (Ob, Yenisei, Lena, Mackenzie, etc.) increases the temperature and reduces the salinity of water masses. The temperature of surface waters is low for most of the year, close to the freezing point of water at a given salinity (from -1 to -2°C). Only in subarctic latitudes in summer it rises to +5...+8°С.
Year-round existence of ice - salient feature ocean nature. Multi-year ice predominates pack, with a thickness of 2-4 m or more. Every year more ice is formed during the winter than it melts in the summer. Excess ice is carried mainly into the Atlantic Ocean. In summer, the seas of the ocean near the coasts of the continents are largely freed from ice.
organic world . The basis of biomass in the ocean is formed by cold-hardy diatoms. They live both in water and on ice. Zoo- and phytoplankton develop in the near-Atlantic sector of the ocean and in coastal waters near the mouths of rivers; characterized by algae growing at the bottom. Commercial fish (cod, haddock, navaga, halibut, etc.) live on the territory of the ocean and in the seas; seals, walruses, beluga whales, and polar bears are common among mammals.
natural complexes. The main part of the ocean area is located within the northern - Arctic natural belt of the World Ocean. However, the seas of the ocean lie in the northern subpolar zone, and the Norwegian Sea belongs to the temperate zone.
north polar belt- this is the central part of the ocean, which is the deepest and most severe in terms of climatic and ice conditions. The boundary of this belt coincides approximately with the edge of the shelf. Throughout the year, most of the water area is covered with drifting ice. Characteristic heaps of ice - hummocks, up to 10-12 m high, arising under the influence of currents, winds and tides. Seals, walruses, polar bears live only on the outskirts of the belt.
subarctic belt includes marginal and inland seas adjacent to land. Their nature is less severe. In summer, the waters off the coast are free of ice, strongly desalinated by river waters. In water areas where warm waters penetrate, there are a lot of plankton and fish; on the rocks of the islands and coasts, birds (“bird markets”) settle.
Economic use . The Arctic Ocean has a large economic importance for Russia, which goes to him for a huge distance, as well as for Canada and some other countries. The economic and technical level of these countries makes it possible to develop the harsh waters of the ocean.
In our country are great work development Northern Sea Route, through which cargo is provided to vast areas of Siberia and Far East. Icebreakers, including nuclear ones, are used to pilot ships. The necessary scientific and operational maintenance of the needs of the fleet and polar aviation is being carried out.
biological resources oceans are small. However, in the Atlantic sector of the ocean, biological productivity is increasing. There is intensive fishing; the local population fishes for seals, ringed seals, and walruses.
Mineral resources of the Arctic oceans are still poorly understood. However, the exploitation of oil and gas fields has begun on the shelf, placer deposits of heavy metals have been discovered. severe natural conditions constrain the exploration and development of already discovered mineral deposits.
Bogdanov D.V. Regional physical geography of the World Ocean. M.: Higher school, 1985. 176 p.
Korinskaya V.A., Dushina I.V., Shchenev V.A. Geography of continents and oceans: Textbook for grade 7 high school. 3rd ed., revised. Moscow: Education, 1993. 287 p.
Stepanov V.N. The nature of the oceans. Moscow: Education, 1982. 189 p.
Countries and peoples: Popular science geographical and ethnographic publication: In 20 vols. M .: Thought, 1978-1985. (Volumes: Africa. Overview. North Africa; Australia and Oceania. Antarctica; America. Overview. North America; South America; Foreign Europe. General review. Northern Europe; Overseas Asia. General review. Southwest Asia).
TableVIII.2
Water balance of Russia by sea basins
Sea basins | Elements of water balance | Coefficient |
||||||
Volume, km 3 | water runoff |
|||||||
Evaporation | Evaporation | |||||||
Bely and Barents | ||||||||
Baltic | ||||||||
Black and Azov | ||||||||
Caspian | ||||||||
Biological resources of the Atlantic Ocean and features of their development.
It has significant biological resources, which is associated with a relatively developed shelf. The active general circulation of waters forms vast zones of increased biological productivity in the ocean. The Atlantic Ocean is the most productive of all the basins of the World Ocean (260 kg/km2). Its most productive zone, the shelf, occupies 7.4% of the total water area in the ocean. The most productive zones are the upwelling areas off the coast of Portugal, North-West. and Southwest. Africa, convective mixing of the Atlantic waters and the waters of the Polar Basin (the Gulf Stream and its system). Local zones exist in the North. the sea off the southern coast of Norway, off South America (along the Falkland Current). Until 1958 Atl. the ocean was the leader in fish catches and seafood production. However, many years of intensive fishing had a negative impact on the raw material base in the 1990s. catches were 22-24 million tons with minor annual fluctuations. The largest catch is given by the North-East (45.6%) (Increased intensity of formation organic matter planktonic algae in the process of photosynthesis, as well as a high content of zooplankton biomass in a 100-meter layer provide high fish productivity in open and coastal waters: from 500 kg / km 2 on the distant approaches to the coast of Iceland, Portugal, France up to 1000 kg / km 2 off the coast of Great Britain and in the North Sea), Central-Eastern (15.6%), South-West (9.3%) and North-West (9.2%) fishing areas. Among the leading fishing countries, whose catches exceed 1 million tons, at the beginning of the XXI century. The USA, Canada, Norway, Iceland, Denmark, Russia, Spain, Morocco were included. Argentina (0.9 million tons), Great Britain (0.73 million tons) and South Africa (0.75 million tons) are close to the group of leading countries.
Energy and chemical resources of the Atlantic Ocean.
In the waters of Atl. ocean, the largest producers of desalinated water are the USA, Tunisia, Libya, the Netherlands, Cuba, Spain (Canary Islands). The Atlantic countries extract from sea water table salt, magnesium, bromine (Great Britain, Italy, France, Spain, Canada, Argentina, etc.) To meet the water needs of 100 million people, the annual volume of desalination should be 10 million m 3. The main producers in Atl. ocean are Türkiye, Bulgaria, the countries of the North. Africa. In the US, about 5% of the salt consumed comes from sea waters. MG- Great Britain, France, USA, Italy, Tunisia, Israel, Canada, Germany, Mexico lead from sea water in the ocean. Offshore mining provides about 60% of the world's magnesium production. BR- Despite its low concentration, bromine became the first substance of industrial extraction, it is widely used as an anti-knock additive in the production of gasoline. Large plants for the extraction of bromine from sea water have been established in the USA, Great Britain, Argentina, and Canada. K- Dead Sea in Israel, Italy. Energy is possessed by sea currents, waves, tides, vertical movements of water. Energy can be generated due to the temperature difference between surface and deep waters. Mankind has practically begun the development of the energy of the tides, developed projects for the use of the energy of waves, surf and currents. The first industrial TPP was built in France (in 1967, with a capacity of 240 thousand kW) at the mouth of the river. Rance, where the tide reaches 13.5 m. More powerful TPPs are being designed - in the bay of Mont Saint-Michel in France (with a capacity of 10 million kW), in the estuary of the river. The Severn, which flows into the Bristol Bay in England. A joint American-Canadian TPP with a capacity of 1 million kW was designed in the Bay of Fundy. Small sea-thermal stations have been created in France, research is underway in the USA. French specialists have created a sea-thermal station off the coast of Côte d'Ivoire
Climate and hydrological regime of the waters of the Atlantic Ocean. Hydrological resources.
Diversity climatic conditions on the surface of the Atlantic Ocean is determined by its large meridional extent and the circulation of air masses under the influence of four main atmospheric centers: Greenland and Antarctic maximums, Icelandic and Antarctic minimums. In addition, two anticyclones constantly operate in the subtropics: Azores and South Atlantic. They are separated by an equatorial region of low pressure. This distribution of baric regions determines the system of prevailing winds in the Atlantic. The greatest influence on the temperature regime of the Atlantic Ocean is exerted not only by its large meridional extent, but also by water exchange with the Arctic Ocean, the seas of the Antarctic and the Mediterranean Sea. Tropical latitudes are characterized by tempera. - 20°C. To the north and south of the tropics are subtropical zones with more noticeable seasonal ones (from 10 ° C in winter to 20 ° C in summer). Tropical hurricanes are a frequent occurrence in the subtropical zone. In temperate latitudes, the average temperature of the warmest month is kept within 10-15 °C, and the coldest -10 °C. Precipitation is about 1000 mm.
surface currents. North Equatorial Current (t)> Antilles (t)> Mexico. Gulf>Florida(t)>Gulf Stream>North Atlantic(t)>Canary(x)>Northern Equatorial Current(t) – northern circle.
South trade winds> Guiana temp. (North) and the Brazilian Warm. (south)>tech. Western winds (x)> Benguela (x)> South trade winds - southern circle.
There are several levels in the Atlantic Ocean deep currents. A powerful countercurrent passes under the Gulf Stream, the main core of which lies at a depth of up to 3500 m, with a speed of 20 cm/s. The powerful deep Louisiana current is observed in the eastern part of the Atlantic Ocean, formed by the bottom runoff of saltier and warmer Mediterranean waters through the Strait of Gibraltar.
The greatest tide values are confined to the Atlantic Ocean, which are noted in the fjord bays of Canada (in Ungava Bay - 12.4 m, in Frobisher Bay - 16.6 m) and Great Britain (up to 14.4 m in Bristol Bay). The highest tide in the world is recorded in the Bay of Fundy, on the east coast of Canada, where the maximum tide reaches 15.6-18 m.
Salinity. The highest salinity of surface waters in the open ocean is observed in the subtropical zone (up to 37.25 ‰), and the maximum in the Mediterranean Sea is 39 ‰. In the equatorial zone, where the maximum amount of precipitation is noted, salinity decreases to 34 ‰. A sharp desalination of water occurs in the estuarine areas (for example, at the mouth of La Plata 18-19 ‰).
Ice formation. Ice formation in the Atlantic Ocean occurs in the Greenland and Baffin Seas and Antarctic waters. The main source of icebergs in the South Atlantic is the Filchner Ice Shelf in the Weddell Sea. Floating ice in the northern hemisphere reaches 40°N in July.
Upwelling. A particularly powerful upwelling zone stretches along the entire western coast of Africa, due to the wind<связан. с пассатной циркуляцией. Также это зоны у Зелёного мыса, у берегов Анголы и Конго. Эти области наиболее благоприятны для развития орг. мира.
The bottom flora of the northern part of the Atlantic is represented by brown (mainly fucoids, and in the subditoral zone by kelp and alaria) and red algae. In the tropical zone, green (caulerpa), red (calcareous lithotamnia) and brown algae (sargasso) predominate. In the southern hemisphere, bottom vegetation is mainly represented by kelp. Phytoplankton of the Atlantic Ocean has 245 species: peridine, coccolithophorids, diatoms. The latter have a clearly defined zonal distribution; the maximum number of them lives in temperate latitudes of the northern and southern hemispheres. The population of diatoms is most dense in the strip of the Current of the Western Winds.
The distribution of the fauna of the Atlantic Ocean has a pronounced zonal character. In the subantarctic and antarctic In the waters of fish, notothenia, blue whiting and others are of commercial importance. Benthos and plankton in the Atlantic are poor in both species and biomass. In the subantarctic zone and in the adjacent zone of the temperate zone, the biomass reaches its maximum. In zooplankton, copepods and pteropods predominate; in nekton, whales (blue whales), pinnipeds, and their fish are nototheniids. In the tropical zone, zooplankton is represented by numerous species of foraminifers and pteropods, several species of radiolarians, copepods, larvae of molluscs and fish, as well as siphonophores, various jellyfish, large cephalopods (squids), and octopuses among benthal forms. Commercial fish are represented by mackerel, tuna, sardines, in areas of cold currents - anchovies. To tropical and subtropical corals are confined to zones. temperate latitudes northern hemisphere are characterized by abundant life with a relatively small diversity of species. Of the commercial fish, the most important are herring, cod, haddock, halibut, and sea bass. The most common zooplankton species are foraminifera and copepods. The greatest abundance of plankton is in the area of the Newfoundland Bank and the Norwegian Sea. The deep-sea fauna is represented by crustaceans, echinoderms, specific fish species, sponges, and hydroids. Several species of endemic polychaetes, isopods, and holothurians have been found in the Puerto Rico Trench.
There are 4 biogeographic regions in the Atlantic Ocean: 1. Arctic; 2. North Atlantic; 3. Tropical-Atlantic; 4. Antarctic.
biological resources. The Atlantic Ocean provides 2/5 of the world catch and its share decreases over the years. In subantarctic and antarctic waters, notothenia, blue whiting and others are of commercial importance, in the tropical zone - mackerel, tuna, sardine, in areas of cold currents - anchovies, in temperate latitudes of the northern hemisphere - herring, cod, haddock, halibut, sea bass. In the 1970s, due to overfishing of some fish species, the volume of fishing fell sharply, but after the introduction of strict limits, fish stocks are gradually recovering. Several international fisheries conventions operate in the Atlantic Ocean basin, which aim at the efficient and rational use of biological resources, based on the application of scientifically based measures to regulate fishing.
help me please..1) What rivers of Eurasia do not freeze?
a) Yenisei
b) Vistula
c) Yangtze
d) Volga
e) Ganges
f) Thames
g) Pechora
h) Cupid
i) Seine
2.. Establish a correspondence between the rivers of South America and some of their features
a) Amazon 1) Hard mode
b) Parana 2) on its tributary is the Iguazu Falls
c) Orinoco 3) a sharp drop in water level in one of the seasons
4) the river has the largest basin
5) Angel Falls is located on its tributary
platforms. Where are they located?
3. Which continents are based on one ancient platform, and which are several platforms?
4. Do earthquakes occur on most ancient platforms, do volcanoes erupt?
5. How many epochs of folding (mountain building) do scientists distinguish?
6. Why do you think the areas of new folding and zones of earthquakes and volcanism most often coincide?
7. determine how the structure of the earth's crust is manifested in the relief. To do this, compare the map of the structure of the earth's crust and the physical map of the world in the atlas. What landforms correspond to ancient platforms; areas of folding? Make a conclusion about the reasons for the identified patterns.
Some areas of the Atlantic shelf are rich in coal. Great Britain conducts the largest underwater mining of coal. The largest exploited Nor Tumberland Derham field with reserves of about 550 million tons is located on the northeast coast of England. Coal deposits have been explored in the shelf zone northeast of Cape Breton Island. However, in the economy, underwater coal is of less importance than offshore oil and gas fields. The main supplier of monazite to the world market is Brazil. The United States is also the leading producer of ilmenite, rutile and zircon concentrates (placers of these metals are almost ubiquitous on the shelf of North America - from California to Alaska). Of considerable interest are cassiterite placers off the coast of Australia, off the Cornwall peninsula (Great Britain), and in Brittany (France). The largest deposits of ferruginous sands are located in Canada. Ferrous sands are also mined in New Zealand. Alluvial gold in coastal marine deposits has been found on the western coasts of the United States and Canada.
The main deposits of coastal-marine diamondiferous sands are concentrated on the southwestern coast of Africa, where they are confined to deposits of terraces, beaches, and shelves down to depths of 120 m. Significant offshore terrace diamond placers are located in Namibia. African coastal-marine placers are promising. In the coastal zone of the shelf there are underwater deposits of iron ore. The most significant development of offshore deposits of iron ore is carried out in Canada, on the east coast of Newfoundland (the Wabana deposit). In addition, Canada mines iron ore in the Hudson Bay.
Fig.1. Atlantic Ocean
In small quantities, copper and nickel are mined from underwater mines (Canada - in the Hudson Bay). Tin is mined on the Cornwall peninsula (England). In Turkey, on the coast of the Aegean Sea, mercury ores are being developed. Sweden mines iron, copper, zinc, lead, gold and silver in the bowels of the Gulf of Bothnia. Large salt sedimentary basins in the form of salt domes or stratal deposits are often found on the shelf, slope, foot of the continents and in deep-sea basins (Gulf of Mexico, shelves and slopes of West Africa, Europe). The minerals of these basins are represented by sodium, potassium and magnesite salts, gypsum. Calculation of these reserves is difficult: the volume of potassium salts alone is estimated in the range from hundreds of millions of tons to 2 billion tons. Two salt domes are being exploited in the Gulf of Mexico off the coast of Louisiana.
More than 2 million tons of sulfur are extracted from underwater deposits. Exploited the largest accumulation of sulfur Grand Isle, located 10 miles from the coast of Louisiana. Commercial reserves of phosphorites have been found near the Californian and Mexican coasts, along the coastal zones of South Africa, Argentina, off the coast of New Zealand. Phosphorites are mined in the California region from depths of 80-330 m, where the concentration averages 75 kg/m3.
A large number of offshore oil and gas fields have been discovered in the Atlantic Ocean and its seas, including those with one of the highest levels of production of these fuels in the world. They are located in different areas of the ocean shelf zone. In its western part, the bowels of the Maracaibo lagoon are distinguished by very large reserves and production volumes. Oil is extracted here from more than 4,500 wells, from which in 2006 93 million tons of "black gold" were produced. The Gulf of Mexico is considered to be one of the richest offshore oil and gas regions in the world, believing that only a small part of potential oil and gas reserves have been identified in it at present. 14,500 wells have been drilled at the bottom of the bay. In 2011, 60 million tons of oil and 120 billion m 3 of gas were produced from 270 offshore fields, and in total, 590 million tons of oil and 679 billion m 3 of gas were extracted here during the development period. The most significant of them are located off the coast of the Paraguano Peninsula, in the Gulf of Paria and off the island of Trinidad. Oil reserves here amount to tens of millions of tons.
In addition to the above areas, three large oil and gas provinces can be traced in the western Atlantic. One of them stretches from the Davis Strait to the latitude of New York. Within its limits, commercial oil reserves have so far been identified near Labrador and south of Newfoundland. The second oil and gas province stretches along the coast of Brazil from Cape Calcañar in the north to Rio de Janeiro in the south. 25 deposits have already been discovered here. The third province occupies the coastal areas of Argentina from the Gulf of San Jorge to the Strait of Magellan. Only small deposits have been discovered in it, so far unprofitable for offshore development.
In the shelf zone of the eastern coast of the Atlantic, oil shows have been discovered south of Scotland and Ireland, off the coast of Portugal, in the Bay of Biscay. A large oil and gas region is located near the African continent. About 8 million tons are produced by the oil fields concentrated near Angola.
Very significant oil and gas resources are concentrated in the depths of some seas of the Atlantic Ocean. Among them, the most important place is occupied by the North Sea, which knows no equal in terms of the pace of development of underwater oil and gas fields. Significant underwater deposits of oil and gas have been explored in the Mediterranean Sea, where 10 oil and 17 offshore gas fields are currently operating. Significant volumes of oil are extracted from fields located off the coasts of Greece and Tunisia. Gas is being developed in the Gulf of Sidra (Bol. Sirte, Libya), off the Italian coast of the Adriatic Sea. In the future, the subsoil of the Mediterranean Sea should produce at least 20 million tons of oil per year.
