To the question Describe the mineral and biological resources of the Atlantic Ocean. Please, help. given by the author hospitality the best answer is The distribution of the fauna of the Atlantic Ocean has a pronounced zonal character. In the subantarctic and antarctic waters, notothenia, blue whiting and others are of commercial importance from fish. 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. Copepods and pteropods predominate in zooplankton, while whales (blue whales), pinnipeds, and nototheniids predominate in nekton. In the tropical zone, zooplankton is represented by numerous species of foraminifera 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. Corals are confined to tropical and subtropical zones. The temperate latitudes of the northern hemisphere are characterized by abundant life with a relatively small variety of species. Of the commercial fish, the most important are herring, cod, haddock, halibut, 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 species of fish, the volume of fishing fell sharply, but after the introduction of strict limits, fish stocks are gradually restored. Several international fisheries conventions operate in the Atlantic Ocean basin, aiming at efficient and rational use biological resources, based on the application of scientifically based measures to regulate the fishery.
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the World Ocean, the area with the seas is 91.6 million km 2; average depth 3926 m; the volume of water is 337 million m 3 . Includes: Mediterranean seas (Baltic, North, Mediterranean, Black, Azov, Caribbean with the Gulf of Mexico), little isolated seas (in the North - Baffin, Labrador; near Antarctica - Scotia, Weddell, Lazareva, Riiser-Larsen), large bays (Guinean , Biscay, Hudson, Over Lawrence). Islands of the Atlantic Ocean: Greenland (2176 thousand km 2), Iceland (103 thousand km 2), (230 thousand km 2), Greater and Lesser Antilles (220 thousand km 2), Ireland (84 thousand km 2), Cape Verde (4 thousand km 2), Faroe (1.4 thousand km 2), Shetland (1.4 thousand km 2), Azores (2.3 thousand km 2), Madeira (797 km 2), Bermuda (53.3 km 2) and others (See map).
Historical outline. The Atlantic Ocean became an object of navigation from the 2nd millennium BC. In the 6th century BC. Phoenician ships sailed around Africa. Ancient Greek navigator Pytheas in the 4th century BC sailed to the North Atlantic. In the 10th century AD. Norman navigator Eric the Red explored the coast of Greenland. In the Age of the Great geographical discoveries(15-16 centuries) the Portuguese master the way to the Indian Ocean along the coast of Africa (Vasco da Gama, 1497-98). Genoese H. Columbus (1492, 1493-96, 1498-1500, 1502-1504) discovered the islands caribbean and . In these and subsequent travels, the outlines and nature of the coasts were established for the first time, coastal depths, directions and speeds of currents were determined, climatic characteristics Atlantic Ocean. The first soil samples were taken by the English scientist J. Ross in the Baffin Sea (1817-1818 and others). Temperature, transparency and other measurements were determined by the expeditions of Russian navigators Yu. F. Lisyansky and I. F. Kruzenshtern (1803-06), O. E. Kotsebu (1817-18). In 1820, the Russian expedition of F. F. Bellingshausen and M. P. Lazarev discovered Antarctica. Interest in the study of the relief and soils of the Atlantic Ocean increased in the middle of the 19th century due to the need to lay transoceanic telegraph cables. Dozens of ships measured depths and took soil samples (American vessels "Arktik", "Cyclops"; English - "Lighting", "Porcupine"; German - "Gazelle", "Valdivia", "Gauss"; French - "Travier", " Talisman, etc.).
An important role in the study of the Atlantic Ocean was played by the British expedition aboard the Challenger (1872-76), based on which, using other data, the first relief and soils of the World Ocean were compiled. The most important expeditions of the 1st half of the 20th century: German on the Meteor (1925-38), American on the Atlantis (30s), Swedish on the Albatross (1947-48). In the early 50s, a number of countries, primarily and, launched extensive research and geological structure bottom of the Atlantic Ocean using accurate echo sounders, the latest geophysical methods, automatic and controlled underwater vehicles. Great work has been carried out by modern expeditions on the ships Mikhail Lomonosov, Vityaz, Zarya, Sedov, Equator, Ob, Akademik Kurchatov, Akademik Vernadsky, Dmitry Mendeleev, etc. 1968 Deep-sea drilling started on board the American vessel Glomar Challenger.
Hydrological regime. There are 4 large-scale gyres in the upper layer of the Atlantic Ocean: the Northern cyclonic gyre (to the north of 45° north latitude), the anticyclonic gyre of the Northern Hemisphere (45° north latitude - 5° south latitude), the anticyclonic gyre of the Southern Hemisphere (5° south latitude - 45° south latitude), Antarctic circumpolar current of cyclonic rotation (45 ° south latitude - Antarctica). On the western periphery of the gyres there are narrow but powerful currents (2-6 km/h): Labrador - Northern cyclonic gyre; the Gulf Stream (the most powerful current in the Atlantic Ocean.), the Guiana Current - the Northern Anticyclonic Gyre; Brazilian-Southern Anticyclonic Gyre. In the central and eastern regions of the ocean, the currents are relatively weak, with the exception of the equatorial zone.
Bottom waters are formed when sinking surface water in polar latitudes (their average temperature is 1.6 ° C). In some places they move at high speeds (up to 1.6 km/h) and are able to erode sediments, carry suspended material, creating underwater valleys and large bottom accumulative landforms. Cold and slightly saline near-bottom Antarctic waters penetrate through the bottoms of basins in the western regions of the Atlantic Ocean up to 42° north latitude. The average temperature of the Atlantic Ocean at the surface is 16.53°C (the South Atlantic is 6°C colder than the North). The warmest waters average temperature 26.7°С are observed at 5-10° north latitude (thermal equator). To Greenland and Antarctica, the water temperature drops to 0 ° C. The salinity of the waters of the Atlantic Ocean is 34.0-37.3 0/00, the highest density of water is over 1027 kg / m 3 in the northeast and south, towards the equator it decreases to 1022.5 kg / m 3. Tides are predominantly semi-diurnal (highest 18 m in the Bay of Fundy); in some areas, mixed and daily tides of 0.5-2.2 m are observed.
Ice. In the northern part of the Atlantic Ocean, ice forms only in the inland seas of temperate latitudes (Baltic, Northern and Sea of Azov, Gulf of Saint Lawrence); a large amount of ice and icebergs is carried out of the Arctic Ocean (Greenland and Baffin Seas). In the South Atlantic Ocean, ice and icebergs form off the coast of Antarctica and in the Weddell Sea.
Relief and geological structure. Within the Atlantic Ocean, a powerful north-south stretching mountain system- The Mid-Atlantic Ridge, which is an element of the global system of Mid-Ocean Ridges, as well as deep-water basins and (map). The Mid-Atlantic Ridge extends for 17,000 km at a latitude of up to 1,000 km. Its crest is dissected in many areas by longitudinal gorges - rift valleys, as well as transverse depressions - transform faults, which break it into separate blocks with a latitudinal displacement relative to the axis of the ridge. The relief of the ridge, strongly dissected in the axial zone, flattens out towards the periphery due to the burial of sediments. The epicenters of shallow-focus are localized in the axial zone along the crest of the ridge and in areas. Deep-sea basins are located along the outskirts of the ridge: in the west - Labrador, Newfoundland, North American, Brazilian, Argentinean; in the east - European (including Icelandic, Iberian and Irish Trench), North African (including Canary and Cape Verde), Sierra Leone, Guinean, Angolan and Cape. Within the ocean floor, abyssal plains, hill zones, uplifts, and seamounts are distinguished (map). Abyssal plains stretch in two discontinuous bands in the coastal parts of deep-sea basins. These are the flattest areas of the earth's surface, the primary relief of which is leveled by precipitation 3-3.5 km thick. Closer to the axis of the Mid-Atlantic Ridge, at a depth of 5.5-6 km, there are zones of abyssal hills. Oceanic rises are located between the continents and the mid-ocean ridge and separate the basins. The largest uplifts: Bermuda, Rio Grande, Rockall, Sierra Leone, Whale Ridge, Canary, Madeira, Cape Verde, etc.
There are thousands of seamounts known in the Atlantic Ocean; almost all of them are probably volcanic edifices. The Atlantic Ocean is characterized by a discontinuous cutting of the geological structures of the continents by the coastline. The depth of the edge is 100-200 m, in the polar regions 200-350 m, the width is from several kilometers to several hundred kilometers. The most extensive shelf areas are near the island of Newfoundland, in the North Sea, the Gulf of Mexico and off the coast of Argentina. The relief of the shelf is characterized by longitudinal grooves, along the outer edge -. The continental slope of the Atlantic Ocean has a slope of several degrees, a height of 2-4 km, terrace-like ledges and transverse canyons are characteristic. Within the sloping plain (the foot of the mainland), the "granite" layer of the continental crust is wedged out. The transition zone with a special structure of the crust includes the marginal deep-water trenches: Puerto Rico (maximum depth 8742 m), South Sandwich (8325 m), Cayman (7090 m), Oriente (up to 6795 m), within which are observed as shallow, and deep-focus earthquakes (map).
The similarity of the contours and geological structure of the continents surrounding the Atlantic Ocean, as well as the increase in the age of the basalt bed, the thickness and age of sediments with distance from the axis of the mid-ocean ridge served as the basis for explaining the origin of the ocean within the concept of Mobilism. It is assumed that the North Atlantic was formed in the Triassic (200 million years ago) during the separation of North America from Northwest Africa, the South - 120-105 million years ago during the separation of Africa and South America. The connection of the basins occurred about 90 million years ago (the youngest age of the bottom - about 60 million years - was found in the northeast of the southern tip of Greenland). Subsequently, the Atlantic Ocean expanded with constant new formation of the crust due to effusions and intrusions of basalts in the axial zone of the mid-ocean ridge and its partial subsidence into the mantle in marginal trenches.
Mineral resources . Among the mineral resources of the Atlantic Ocean, gas is also of the greatest importance (map to World Ocean station). North America has oil and gas bearing Labrador Sea, bays: St. Lawrence, Nova Scotia, Georges Bank. Oil reserves on the eastern shelf of Canada are estimated at 2.5 billion tons, gas 3.3 trillion. m 3 , on the eastern shelf and continental slope of the United States - up to 0.54 billion tons of oil and 0.39 trillion. m 3 gas. More than 280 fields have been discovered on the southern shelf of the United States, and more than 20 fields off the coast (see). More than 60% of Venezuela's oil is produced in the Maracaibo lagoon (see). The deposits of the Gulf of Paria (Trinidad Island) are actively exploited. The total reserves of the Caribbean Sea shelves are up to 13 billion tons of oil and 8.5 trillion. m 3 gas. Oil and gas bearing areas have been identified on the shelves (Toduz-yc-Santos Bay) and (San Xopxe Bay). Oil fields have been discovered in the North (114 fields) and the Irish Seas, the Gulf of Guinea (50 offshore Nigeria, 37 off Gabon, 3 off the Congo, etc.).
The predicted oil reserves on the Mediterranean shelf are estimated at 110-120 billion tons. Deposits are known in the Aegean, Adriatic, Ionian seas, off the coast of Tunisia, Egypt, Spain, etc. Sulfur is mined in the salt-dome structures of the Gulf of Mexico. With the help of horizontal underground workings, coal is mined from coastal mines in offshore extensions of continental basins - in Great Britain (up to 10% of national production) and Canada. Off the east coast of Newfoundland is the largest iron ore deposit, Waban (total reserves of about 2 billion tons). Tin deposits are being developed off the coast of Great Britain (Cornwall Peninsula). Heavy minerals ( , ) are mined off the coast of Florida, in the Gulf of Mexico. off the coast of Brazil, Uruguay, Argentina, the Scandinavian and Iberian Peninsulas, Senegal, South Africa. The shelf of South West Africa is an area of industrial diamond mining (reserves 12 million). Gold-bearing placers have been discovered off the Nova Scotia Peninsula. found on the shelves of the United States, on the Agulhas Bank. The largest fields of ferromanganese nodules in the Atlantic Ocean are found in the North American Basin and on the Blake Plateau near Florida; their extraction is still unprofitable. The main sea routes in the Atlantic Ocean, along which minerals are transported, were mainly formed in the 18-19 centuries. In the 1960s, the Atlantic Ocean accounted for 69% of all maritime transportation, except for floating craft; pipelines are used to transport oil and gas from offshore fields to shore. The Atlantic Ocean is increasingly polluted with oil products, wastewater from industrial substances of enterprises containing pesticides, radioactive and other substances that harm marine flora and fauna, concentrate in marine food products, posing a great danger to humanity, which requires adoption. effective measures to prevent further pollution of the ocean environment.
Oceanological conditions in large areas of the Atlantic Ocean are favorable for the development of life, therefore, of all the oceans, it is the most productive (260 kg / km 2). Until 1958, he was a leader in the extraction of fish and non-fish products. However, many years of intensive fishing had a negative impact on the resource base, which led to a slowdown in the growth of catches. At the same time, a sharp increase in the catch of the Peruvian anchovy began, and the Atlantic Ocean gave way to the Pacific in catches. In 2004, the Atlantic Ocean provided 43% of the world's catch. The volume of production of fish and non-fish objects fluctuates both over the years and over the areas of production.
Mining and fishing
Most of the catch comes from the Northeast Atlantic. This district is followed by the Northwestern, Central Eastern and Southeastern regions; The North Atlantic has been and continues to be the main fishing area, although in 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 in 2006 by 1,985 thousand tons. Against the background of this general decrease in catches in two areas 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.
An analysis of fisheries (including non-fish species) in the Atlantic Ocean in recent years has revealed the main causes of changes in catches in different fishing areas.
In the North-West region of the ocean, production has decreased due to the strict regulation of fishing in the 200-mile zones of the United States and Canada. At the same time, these states have begun to pursue a discriminatory policy against the socialist countries here, sharply limiting their catch quotas, although they themselves do not use the raw material base of the region to the full extent.
The increase in catches in the Southwest Atlantic is associated with an increase in catches in South America.
In the South-East Atlantic, the total catch of African countries has decreased, but at the same time, compared with 2006, the catches of almost all states conducting expeditionary fishing here, and transnational corporations, whose nationality is difficult to determine by FAO, have increased.
In the Antarctic part of the Atlantic Ocean in 2009, the total volume of production reached 452 thousand tons, of which 106.8 thousand tons were accounted for by crustaceans.
The data presented indicate that in modern conditions the extraction of biological resources in the Atlantic Ocean has largely become determined by legal and political factors.
Coastal marine placers rich in ilmenite, rutile, zircon, and monocyte are represented by large deposits on the coasts of Brazil and the Florida peninsula (USA). On a smaller scale, minerals of this type are concentrated off the coast of Argentina, Uruguay, Denmark, Spain, and Portugal. Tin-bearing and ferruginous sands are found on the Atlantic coast of North America and Europe, and coastal-marine placers of diamonds, gold, platinum are found off the coast of South-West Africa (Angola, Namibia, South Africa). On the shelf of the Atlantic coast of North and South America and Africa (Blake Plateau, near Morocco, Liberia, etc.), phosphorite formations and phosphate sands have been found (the extraction of which is still unprofitable due to their lower quality compared to land phosphorites). Extensive fields of ferromanganese nodules are located in the northwestern part of the ocean, in the North American Basin and on the Blake Plateau. The total reserves of ferromanganese nodules in the Atlantic Ocean are estimated at 45 billion tons. The level of concentration of non-ferrous metals in them (with a low content of manganese) is close to that of ore-bearing land rocks. A large number of offshore oil and gas fields have been discovered in the Atlantic Ocean and its seas, which are being intensively developed. The richest offshore oil and gas regions of the world include the Gulf of Mexico, the Maracaibo lagoon, the North Sea, the Gulf of Guinea, which are being intensively developed. Three large oil and gas provinces have been identified in the Western Atlantic: 1) from the Davis Strait to the latitude of New York (commercial reserves near Labrador and south of Newfoundland); 2) offshore Brazil from Cape Kalkanyar to Rio de Janeiro (more than 25 fields have been discovered); 3) in the coastal waters of Argentina from the Gulf of San Jorge to the Strait of Magellan. According to estimates, promising oil and gas areas make up about 1/4 of the ocean, and the total potential recoverable oil and gas resources are estimated at more than 80 billion tons. Some areas of the Atlantic shelf are rich in coal (Great Britain, Canada), iron ore (Canada, Finland) .
24. Transport system and ports of the Atlantic Ocean.
Leading place among other sea basins of the world. The world's largest cargo flow of oil from the Persian Gulf countries on its way to the Atlantic is divided into two branches: one goes around Africa from the south and goes to Western Europe, North and South America, and the other - through the Suez. Oil from countries North Africa to Europe and, in part, to North America, from the countries of the Gulf of Guinea to the USA and Brazil. From Mexico and Venezuela to the USA via the Caribbean, and from Alaska via the Panama Canal to ports on the Atlantic coast. Liquefied gas from North Africa (Algeria, Libya) to Western Europe and the USA. In the transportation of dry bulk - iron ore (from Brazilian and Venezuelan ports to Europe), grain (from the USA, Canada, Argentina - to European ports), phosphorites (from the USA (Florida), Morocco - Western Europe), bauxite and alumina (from Jamaica, Suriname and Guyana in the USA), manganese (from Brazil, Western and South Africa), chromium ore (from South Africa and the Mediterranean), zinc and nickel ores (from Canada), timber cargo (from Canada, the Scandinavian countries and northern Russian ports to Western Europe). General cargo, 2/3 of which is carried by liner ships. Universal ports with high level mechanization. Western Europe-1/2 cargo turnover. English Channel to the Kiel Canal, East Coast Great Britain, Mediterranean port complexes along the coast of the Gulf of Lion and the Ligurian Sea. United States from the Gulf of Maine to the Chesapeake Bay: New York - New Jersey, Ameriport and Hampton Rhodes. The Gulf of Mexico, where three main port-industrial complexes stand out (New Orleans and Baton Rouge; Galveston Bay and the Houston Canal; the ports of Beaumont, Port Arthur, Orange connected with the Gulf of Mexico by channels through Lake Sabine). oil (Amuay, Cartagena, Tobruk) and chemical (Arzev, Alexandria, Abidjan) plants, al (Belen, San Luis, Puerto Madryn), metallurgy (Tubaran, Maracaibo, Varrizh), cement (Freeport) industries. southeast coast of Brazil (Santos, Rio de Janeiro, Victoria) and in La Plata Bay (Buenos Aires, Rosario, Santa Fe). (Port Harcourt, Lagos, Niger Delta). North African ports are widely open to the sea, and their universal nature requires significant costs for the modernization of port facilities (Algiers, Tripoli, Casablanca, Alexandria and Tunisia). On a number of Caribbean islands (Bahamas, Caymans, Virgin Islands) the deepest transshipment terminals in this part of the ocean for large tankers (400-600 thousand deadweight tons) have been built.
8. Life of the Atlantic Ocean and its biological resources, features of aquatic ecosystems.
Ocean life in the light contemporary ideas 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 scope. Indeed, all aquatic animals and plants, their ranges, forms of existence, biological cycles, sizes, life span of individuals, their energy balance, bioproduction are associated with abiotic factors that 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 ecosystem of the ocean differs from terrestrial ecosystems in a number of fundamental features, of which two seem to be particularly significant. Producers (plants) of terrestrial ecosystems are inextricably linked by the root system with the biogenic fund, which is formed as a result of the vital activity of plants. Producers of aquatic ecosystems (algae) are disconnected from the main biogenic fund of water bodies, whether it be an ocean, a lake, a reservoir, or even a pond. In the photo layer, which does not exceed several tens of meters even with very high transparency of the ocean, 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 out 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 the food of many animals, so their distribution is associated with plant association. In the marine environment, there is a disunity between the animal population (consumers) and phytoplankton fields (producers). Most of the 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 degradation products plant organisms. With depth, the amount of food decreases: 2/3 of the biomass of ocean animals are 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 takes place in twilight lighting, and at great depths in complete darkness. The lack of food causes the rarefied existence of deep-sea organisms. Many representatives of the deep fauna have organs of luminescence, and in some species of fish there are males living on the body of females - an adaptation that eliminates the need for difficult meetings in complete darkness with rarefied distribution. In the life of the hydrosphere, the group of decomposers, or reducing agents, is also important. They feed on the dead remains of animals and plants, and mineralize these remains, bringing them to carbon dioxide, ammonia and water, making them available to autotrophic producing plants. So, in relation to the food organic substances present and formed in the water, the entire aquatic population is combined 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 biomass and production. All animals and plants are combined into three large complexes: plankton, whose representatives drift from 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 animals and plants that make up the permanent complex of plankton, it includes larvae of mollusks, worms, echinoderms, as well as fish fry. A significant amount of plankton are amphipod and euphausiid crustaceans, which are an important component of the diet of many fish species. Euphausiids are especially numerous in the area of the polar front, as well as in the waters surrounding Antarctica, where krill (Euphasia superba), the main food source of baleen whales, is especially numerous.
The composition of the benthos includes mollusks, echinoderms, worms that feed on detritus in the silts. According to the nature of the vertical distribution on the ground, benthic animals are combined into epifauna, infauna. Benthic animals penetrate into the depths of the ocean for several thousand meters. Among the benthic animals, many species are of economic value - these are, first of all, mussels, oysters, spiny lobsters, lobsters.
Most of the nekton biomass is made up of fish, the total number of species of which exceeds 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 in phytoplankton reaches 200-300 units. For zooplankton, this ratio is 2-3 units. In benthos, it decreases to 1/3, and in most fish, to 1 5. At the same time, in fish with a short life cycle this ratio can be as high as 1/2, and in slow-growing fish with a late onset of puberty, it can reach 110.
We will try to show the details of a number of features of ocean life when characterizing individual regions of the Atlantic Ocean.