Biological resources of the Atlantic Ocean. Properties of waters and ocean currents
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Atlantic ocean map
Ocean area – 91.6 million sq. km;
Maximum depth – Puerto Rico Trench, 8742 m;
Number of seas – 16;
The largest seas are the Sargasso Sea, the Caribbean Sea, the Mediterranean Sea;
The largest gulf is the Gulf of Mexico;
The largest islands are Great Britain, Iceland, Ireland;
The strongest currents:
- warm - Gulf Stream, Brazilian, Northern Passat, Southern Passat;
- cold - Bengal, Labrador, Canary, Western Winds.
The Atlantic Ocean occupies the entire space from subarctic latitudes to Antarctica. In the southwest it borders Pacific Ocean, in the southeast with the Indian and in the north with the Arctic. In the northern hemisphere coastline continents washed by waters Arctic Ocean, heavily indented. There are many inland seas, especially in the east.
The Atlantic Ocean is considered a relatively young ocean. The Mid-Atlantic Ridge, which stretches almost strictly along the meridian, divides the ocean floor into two approximately equal parts. In the north, individual peaks of the ridge rise above the water in the form of volcanic islands, the largest of which is Iceland.
Offshore part Atlantic Ocean not big – 7%. The greatest width of the shelf, 200 – 400 km, is in the area of the North and Baltic seas.
The Atlantic Ocean is in all climatic zones, but most of it is in tropical and temperate latitudes. The climatic conditions here are determined by trade winds and westerly winds. Greatest strength winds reach the temperate latitudes of the South Atlantic Ocean. In the region of the island of Iceland there is a center for the generation of cyclones, which significantly affect the nature of the entire Northern Hemisphere.
Average temperatures surface waters in the Atlantic Ocean is much lower than in the Pacific. This is due to the influence of cold waters and ice that come from the Arctic Ocean and Antarctica. In high latitudes there are many icebergs and drifting ice floes. In the north, icebergs slide from Greenland, and in the south from Antarctica. Nowadays, the movement of icebergs is monitored from space by artificial satellites of the earth.
Currents in the Atlantic Ocean have a meridional direction and are characterized by strong activity in the movement of water masses from one latitude to another.
Organic world The Atlantic Ocean is poorer in species composition than the Pacific Ocean. This is explained by geological youth and cooler climatic conditions. But despite this, the reserves of fish and other marine animals and plants in the ocean are quite significant. The organic world is richer in temperate latitudes. More favorable conditions for many species of fish to live in the northern and northwestern parts of the ocean, where there are fewer flows of warm and cold currents. Here the following products are of industrial importance: cod, herring, sea bass, mackerel, capelin.
Stand out for their originality natural complexes individual seas and the inflow of the Atlantic Ocean. This is especially true of the inland seas: Mediterranean, Black, Northern and Baltic. The Sargasso Sea, unique in its nature, is located in the northern subtropical zone. The giant sargassum algae that the sea is rich in made it famous.
The Atlantic Ocean is crossed by important sea routes, which connect the New World with the countries of Europe and Africa. The Atlantic coast and islands are home to world-famous recreation and tourism areas.
The Atlantic Ocean has been explored since ancient times. Since the 15th century, the Atlantic Ocean has become the main waterway of mankind and does not lose its importance today. The first period of ocean exploration lasted until the middle of the 18th century. It was characterized by the study of the distribution of ocean waters and the establishment of ocean boundaries. A comprehensive study of the nature of the Atlantic began with late XIX centuries.
The nature of the ocean is now being studied with more than 40 scientific ships from different countries peace. Oceanologists carefully study the interaction of the ocean and the atmosphere, observe the Gulf Stream and other currents, and the movement of icebergs. The Atlantic Ocean is no longer able to independently restore its biological resources. Preserving its nature today is an international matter.
8. Life of the Atlantic Ocean and its biological resources, features of aquatic ecosystems.
Ocean life in the light modern ideas is considered as an ecosystem (biogeocenosis, according to the terminology of V.N. Sukachev, 1960; L.A. Zenkevich, 1970), interconnected and interdependent by geophysical and geochemical processes and phenomena global scale. Indeed, all aquatic animals and plants, their habitats, forms of existence, biological cycles, sizes, life expectancy of individual individuals, their energy balance, bioproducts are associated with abiotic factors, which are derivatives of the geophysical processes of the planet. In turn, biological processes are of great importance in the formation of the planet within the limits covered by life. The ocean ecosystem differs from terrestrial ecosystems in a number of fundamental features, two of which seem particularly significant. Producers (plants) of terrestrial ecosystems are inextricably linked by the root system with the biogenic fund formed as a result of the life of plants. Producers of aquatic ecosystems (algae) are separated from the main nutrient pool of water bodies, be it the ocean, lake, reservoir, or even pond. In the photic layer, which even with very high transparency of the ocean does not exceed several tens of meters, there are not enough biogenic salts, and, above all, phosphates, but they limit the formation of organic matter. Biogenic elements are located at a depth where light does not penetrate and from where they are carried into the illuminated layer of the sea as a result of vertical mixing of water masses as a result of thermal and mechanical interaction between the atmosphere and the hydrosphere.
In terrestrial ecosystems, plants are the most important component of food for many animals, so their distribution is associated with plant associations. In the marine environment, there is a separation of the animal population (consumers) and phytoplankton fields (producers). Most aquatic biocenoses exist without direct contact with living vegetation, concentrated in a thin near-surface trophogenic layer. The mass of animals lives below the mass of plants, using destruction products plant organisms. With depth, the amount of food decreases: 2/3 of the biomass of ocean animals is in a layer up to 500 m. At great depths, there is a lack of food resources and a decrease in the biomass of the ichthyocene. Thus, the life of most marine animals occurs in twilight lighting, and at great depths - in complete darkness. The lack of food causes the sparse existence of deep-sea organisms. Many representatives of the deep fauna have luminescent organs, and some species of fish have males living on the body of females - an adaptation that eliminates the need for difficult meetings in complete darkness with a sparse distribution. In the life of the hydrosphere important also has a group of decomposers, or reducers. They feed on the dead remains of animals and plants, and mineralize these remains, reducing them to carbon dioxide, ammonia and water, making them available to the barking autotrophic plants - producers. So, in relation to the food available and formed in water organic matter the entire aquatic population is united into three large groups: producers, consumers and decomposers. The ocean is inhabited by about 200 thousand species of plants and animals, and marine researchers would never be able to understand their relationship if the leading role in the life of the ocean did not belong to only a few thousand species, which are the main ones in terms of biomass and production. All animals and plants are united into three large complexes: plankton, whose representatives drift with water masses; benthos, whose representatives live on the ground. And nekton, which includes actively swimming animals - fish, cephalopods and mammals - pinnipeds, dolphins, whales.
In addition to the animals and plants that make up the permanent plankton complex, it includes larvae of mollusks, worms, echinoderms, as well as fish fry. A significant mass of plankton consists of amphipod crustaceans and euphausiids, representing important component nutrition of many types of fish. Euphausiids are especially numerous in the polar front region, as well as in the waters surrounding Antarctica, where krill (Euphasia superba), the main source of food for baleen whales, is especially numerous.
The benthos includes mollusks, echinoderms, and worms that feed on detritus found in the silt. Based on the nature of the vertical distribution on the ground, benthic animals are grouped into epifauna and infauna. Benthic animals penetrate several thousand meters into the depths of the ocean. Among benthic animals, many species are of economic value - these are, first of all, mussels, oysters, lobsters, and lobsters.
Most nekton biomass consists of fish, total species of which exceed 15 thousand. Their biomass reaches 80-85% of the total nekton biomass. In second place are cephalopods (about 600 species), about 15% of the nekton biomass. There are about 100 species of whales and pinnipeds. They make up less than 5% of the total nekton biomass.
Of great practical interest are data characterizing the productivity of the primary source of food - phytoplankton and consumers. The productivity of phytoplankton is enormous compared to its biomass. The ratio of production to biomass reaches 200-300 units in phytoplankton. For zooplankton this ratio is 2-3 units. In benthos it decreases to 1/3, and in most fish it decreases to 1 5. Moreover, in fish with a short life cycle this ratio can be equal to 1/2, and in slow-growing fish with a late onset of sexual maturity it can reach 110.
We will try to show in detail a number of features of ocean life when characterizing individual areas of the Atlantic Ocean.
Oceanological conditions over large areas of the Atlantic Ocean are favorable for the development of life, therefore it is the most productive of all the oceans (260 kg/km2). Until 1958, it was a leader in the production of fish and non-fish products. However, many years of intensive fishing had a negative impact on the raw material base, which led to a slowdown in the growth of catches. At the same time, a sharp increase in the Peruvian anchovy catch began, and the Atlantic Ocean lost primacy in catches to the Pacific. In 2004, the Atlantic Ocean accounted for 43% of the world's catch. The volume of production of fish and non-fish objects varies by year and by area of production.
Mining and fishing
The majority of the catch comes from the Northeast Atlantic. This region is followed by the North-West, Central-East and South-East regions; The North Atlantic has been and continues to be the main fishing area, although last years The role of its central and southern zones has noticeably increased. In the ocean as a whole, catches in 2006 exceeded the annual average for 2001–2005. In 2009, production was lower than the 2006 catch by 1,985 thousand tons. Against the background of this general decrease in catches in two regions of the Atlantic, in the North-West and North-East, production decreased by 2198 thousand tons. Consequently, the main catch losses occurred in the North Atlantic.
Analysis of fisheries (including non-fish objects) in the Atlantic Ocean in recent years has revealed the main reasons for changes in catches in different fishing areas.
In the Northwestern region of the ocean, production has decreased due to strict regulation of fishing within the 200-mile zones of the United States and Canada. At the same time, these states began to pursue a discriminatory policy here towards socialist countries, sharply limiting their fishing quotas, although they themselves do not fully use the raw material base of the region.
Increased catches in the Southwest Atlantic are associated with increased catches by countries South America.
In the South-East Atlantic, the total catch of African countries has decreased, but at the same time, compared to 2006, the catches of almost all states conducting expeditionary fishing here, and multinational corporations, the nationality of which is difficult to determine, have increased.
In the Antarctic part of the Atlantic Ocean in 2009, the total production volume reached 452 thousand tons, of which 106.8 thousand tons were crustaceans.
The data presented indicate that in modern conditions production biological resources in the Atlantic Ocean began to be largely determined by legal and political factors.
To the question: Give a description of the mineral and biological resources of the Atlantic Ocean. Please, help. given by the author hospitable the best answer is The distribution of the fauna of the Atlantic Ocean has a pronounced zonal character. In subantarctic and Antarctic waters, notothenia, 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 temperate zone biomass reaches its maximum. The zooplankton is dominated by copepods and pteropods, and the nekton is dominated by mammals, whales ( blue whale), pinnipeds, their fish are nototheniids. In the tropical zone, zooplankton is represented by numerous species of foraminifera and pteropods, several species of radiolarians, copepods, larvae of mollusks and fish, as well as siphonophores, various jellyfish, large cephalopods (squid), and, among benthic forms, octopuses. Commercial fish are represented by mackerel, tuna, sardines, and in areas of cold currents - anchovies. Corals are confined to tropical and subtropical zones. The temperate latitudes of the northern hemisphere are characterized by abundant life with a relatively small diversity of species. From commercial fish highest value have herring, cod, haddock, halibut, sea bass. Foraminifera and copepods are the most characteristic of zooplankton. 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 species of fish, sponges, and hydroids. Several species of endemic polychaetes, isopods, and holothurians have been found in the Puerto Rico Trench.
There are 4 biogeographical regions in the Atlantic Ocean: 1. Arctic; 2. North Atlantic; 3. Tropico-Atlantic; 4. Antarctic.
Biological resources. The Atlantic Ocean provides 2/5 of the world's catch and its share has been decreasing over the years. In subantarctic and Antarctic waters, notothenia, 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, fishing volumes declined sharply, but after the introduction of strict limits, fish stocks are gradually recovering. There are several international fisheries conventions in the Atlantic Ocean that aim to effectively and efficiently rational use biological resources, based on the application of scientifically based measures to regulate fishing.
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1)Which rivers of Eurasia do not freeze?
a) Yenisei
b) Vistula
c) Yangtze
d) Volga
d) Ganges
e) Thames
g) Pechora
h) Cupid
i) Seine
2.. Establish a correspondence between the rivers of South America and some of their characteristics
a) Amazon 1) Hard mode
b) Parana 2) Iguazu Falls is located on its tributary
c) Orinoco 3) a sharp drop in water level in one of the seasons
4) the river has the largest pool
5) on its tributary there is Angel Falls
platforms. Where are they located?
3. Which continents are based on one ancient platform, and which are based on several platforms?
4. Do earthquakes occur on most ancient platforms and do volcanoes erupt?
5. How many epochs of folding (mountain building) do scientists distinguish?
6. Why do you think areas of new folding and zones of earthquakes and volcanism most often coincide?
7. determine how the structure earth's crust appears in relief. To do this, compare the map of the structure of the earth's crust and physical card world in the atlas. What landforms correspond to ancient platforms; areas of folding? Draw a conclusion about the reasons for the identified patterns.