Truly, the Sargasso Sea is one continuous phenomenon. Sea without shores

Sargasso Sea. The coordinates of this most interesting and dangerous area of ​​the Atlantic are 22-36 degrees north latitude and 32-64 degrees west longitude. The area of ​​the sea is 7 million square meters. kilometers. The climate is close to tropical in terms of temperature, in summer the water surface is about 30 degrees Celsius, and in winter plus 23 degrees. Depth Sargasso Sea a little over 6 thousand meters. Moreover, the temperature of the water at depth differs from the world ocean twice, the Sargasso Sea is very warm.

Seas usually have shores, but Sargasso does not. The Atlantic currents are considered to be the boundaries of its water area, there are only four of them, the Gulf Stream in the west, the North Atlantic in the north, the Canary in the east, and the Trade Wind in the south. All these currents are approximately equal in power, as a result of their circular closed interaction, a vast anticyclone zone is created, in which there are never storms, this zone is the Sargasso Sea. It would seem that there is nothing wrong with the fact that the Atlantic Ocean, in some part, has become a kind of quiet harbor in which ships can take shelter from the weather and wait out the storm.

But in the Sargasso Sea it is too calm, there is always complete calm and there is not a breeze. Swimming into this calm, where the flame of a burning candle does not move and the air is still, is dangerous, you can stay in forever. A light breeze is very rare in the Sargasso Sea, and it is so weak that it cannot fill the ship's sails. Therefore, in those distant times, when there were no mechanical engines yet, and the ships were all completely sailing, falling into the boundless Sargasso Sea, caravels, corvettes, frigates, brigantines became helpless and died after several months of waiting for a fair wind.

The Gulf Stream and other currents not only created the wide Sargasso Sea, but also tried to make it decorative. It is in this area of ​​the Atlantic Ocean that Sargassum grows at the bottom, from which, in fact, the name of the sea, Sargasso, comes from. These algae are strikingly different from all others.

Sargassa is not a ribbon algae, but a bushy one. She has a rhizome, branches, fruits and leaves, like an ordinary bush that grows on land. Life at the bottom of the ocean at the Sargasso is short, its bush is separated from the rhizome and floats to the surface, decorating the Sargasso Sea. Nature endowed the plant with the ability to reproduce in a multitude of air bubbles at the tips of the branches, it is they who help the algae to emerge and confidently stay on the water.

Tireless currents collect bushes in the middle of the sea, and there algae spread like a solid carpet, frightening sailors and marine animals with their unusual appearance. Although the sargasso do not pose any danger to ships - although reluctantly, they disperse under the bowsprit of a moving ship, again closing behind the stern. Sargassums do not carry organic life in themselves, the algae are already dead after they have risen to the surface. Their mass is used by small crustaceans to build their simple houses. Mollusks also adapt to harsh environments. Life in the deadly Sargasso Sea is still there, and it continues.

The Sargasso Sea got its name because of the algae - Sargasso. The algae themselves are relatively small, but strong winds and high standing waves knock them into huge "fields" that stretch for miles across the surface of the sea. There are many legends about ships that disappeared in the sea thickets associated with this sea.

Geography

Located in subtropical latitudes, the Sargasso Sea is the only one in the world that does not have solid shores. It lacks clear geographical boundaries, its area is outlined by strips of currents that form a stagnant center of a closed anticyclonic circulation between the Canary, North Atlantic and North Trade wind currents. Since the boundaries of the currents change from season to season, the size of the sea is not constant and the area varies from 6 to 7 million km 2.
But the depths of the Sargasso Sea are known more precisely: most of it is located in the North American Basin - a lowering of the bottom between the underwater North Atlantic Ridge, the continental slope North America and the underwater elevation of the arc of the West Indies, where depths of over 6000 m prevail.
In the central part of the basin there is the Bermuda underwater plateau, which rises above the sea surface and forms the Bermuda Islands of volcanic origin.
It got its name from the accumulations of Sargasso algae floating on its surface. The abundance of Sargasso in this place is associated with converging surface currents, constant wind and strong waves. That is why the algae are located with the stem part in the direction of the prevailing winds and are arranged in relatively regular rows.
Sargassums are bottom, attached to the bottom of the sea by roots, and floating, torn off from the bottom and held on the surface of the water by small bubbles growing on stems. Because of these bubbles, Sargasso is sometimes called a sea grape. When the algae die, the vesicles they hold on burst and the plants sink.
The mass of algae floating in the sea is difficult to calculate, but approximately ranges from 4 to 11 million tons.
Sargasso, which formed a "forest" in the middle of the ocean, turned into a habitat for a variety of marine life: mackerel, flying fish, pipefish, crab, sea turtle, as well as sea anemones and bryozoans.
The exact date of the appearance of the name of the Sargasso Sea is unknown, but it refers to the XV century. The name of the sea was given by the Portuguese, who explored and reached during their journey to the circulation of the currents of the Atlantic (they called it "volta du mar"). Their eyes appeared "islands" of algae. Presumably, the authorship of the name belongs to the Spanish naturalist Gonzalo de Oviedo y Valdes (1478-1557), who called this space Sargasso, which means "algae" in Portuguese.
The Sargasso Sea was first crossed in 1492 by the expedition of Christopher Columbus (1450-1451), who described it as a "jar of seaweed".
The Sargasso Sea is located in the central part of the Atlantic Ocean, in the center of the circulation formed by the currents of the Gulf Stream, Canary, North Atlantic and North Trade Winds. Most big islands- Bermuda. In the era of sailing ships, it was considered a risky navigation area due to the accumulation of algae - sargasso.
In the Sargasso Sea there is a giant garbage patch of plastic and other waste, formed by ocean currents, gradually collecting garbage thrown into the ocean in one place.
Sargasso Sea - a place of amazing natural phenomenon: spawning of the European river eel. Here, eel fry hatch from eggs and, picked up by the Gulf Stream, move for three years along with the warm water mass to Europe or east coast North America, where they approach the mouths of the rivers and rise upstream. After 9-12 years, the eel returns to the Sargasso Sea, overcoming about 8 thousand km of the way to spawn.
Bermuda - the only major islands in the Sargasso Sea - overseas territory Great Britain, about a thousand kilometers from the coast of North America. Most of the population are descendants of African slaves who once worked here on sugar cane plantations. One third of the population is white. Bermuda - important Finance center off the coast of the United States: thousands of foreign companies, including shipping companies, are registered here. However, the main problem for the islands remains the lack of water: there are no rivers here, and the only source fresh water, as in colonial times, tropical showers remain.
In the era of sailing, sargassums were a serious obstacle to slow-moving caravels, which later gave rise to many legends about islands formed from ships forever stuck in algae. Indeed, in the days of sailboats, ships were found here, stuck among the algae and abandoned by the crew, sometimes with skeletons on board. The names of these vessels and the dates of their disappearance and discovery are precisely known.
The southwestern part of the Sargasso Sea is occupied by the Bermuda Triangle, where, according to supporters of the existence anomalous phenomena, occur mysterious disappearances ships and aircraft. At the same time, explanations are put forward, one more bizarre than the other: abductions by "alien pirates", the activities of the surviving inhabitants of Atlantis, the presence of the "thermal point" of the Earth as a living space object, poisonous gas distributed by plants.
Scientists, in response to fantastic assumptions about the reasons for the disappearance of ships and aircraft, offer more realistic versions of the incidents. The main reason for the appearance of rumors about aliens is the fact that lines pass over Bermuda air traffic from the USA and Canada to Europe, Central and South America.
In the old days, the water of the Sargasso Sea was exceptionally clean, and its transparency reached 60 m. But this is a long time ago: today the waters are heavily polluted with fuel oil, which accumulates on algae.
In addition, algae have become a concentration of floating plastic waste that has formed artificial island called the North Atlantic Garbage Patch. It reaches hundreds of kilometers in length and width. Due to the continuous circular motion of ocean currents, the garbage thrown into the ocean is gradually concentrated in one area, representing a tremendous danger to the ecosystems of the Atlantic.

general information

Islands: Bermuda.

Major port: Hamilton (Bermuda Island) - 1800 people. (2010).
Languages: English, Portuguese.
Ethnic composition: Africans, whites, mestizos.

Religions: Christianity (Protestantism, Methodism, Adventism, Catholicism), Islam.

Monetary units: Bermuda dollar, US dollar.

natural borders(ocean currents): in the west - the Gulf Stream, in the north - the North Atlantic, in the east - the Canary, in the south - the North Tradewind.

Numbers

Width: 1100 km.

Length: 3200 km.
Max Depth: from 6995 to 7100 m (North American Basin).

Salinity: 36.5-37% o.

Climate and weather

Average air temperature in January: from +18 to +24°С.

Average air temperature in July: +26°С.

Average surface water temperature in January: +18°С in the north, +25°С in the south.

Average surface air temperature in July: in the northwest +26°С, in the southeast +28°С.

Average annual rainfall: 1000 mm.

Relative humidity: 70-80%.

Economy

Sea fishing.

Attractions

Curious facts

On September 16, 1492, when the sun rose over the ocean, the sailors of the X. Columbus squadron saw an unknown sight around them. The whole sea up to the horizon was covered with algae. Brown, tangled lumps floated now singly, now in whole fields. Eight days have passed since the caravels were left astern Canary Islands and turned west. X. Columbus triumphed. This means that the longed-for India is very close: accumulations of algae are a sure sign of the proximity of the earth. But a share of bewilderment was mixed with joy - too quickly the squadron reached the goal of its journey, this did not fit with any calculations. However, it wasn't worth it to grieve. The weather was excellent, a warm breeze filled the sails, the algae gently swayed on a gentle wave, the lot did not reach the bottom: the voyage was not only safe, but also pleasant.

A day passed, then another, a week ended, and the stems of three small sailboats continued to push apart the greenish-brown rafts and ridges of strange plants. The ground was still invisible. October came, the number of algae increased every day, from the low side it was visible how some living creatures swarm inside the algal lumps, small brown crabs swim on the surface of the genera, bizarre fish with shaggy, algae-like fins hide under the lumps of plants. There was no shore. The days dragged on. And suddenly it was all over. The algae disappeared somewhere, the wind changed direction, the squadron was moving along clean water. In the early morning of October 12, the long-awaited cry was heard: "Earth!" According to a pre-given order, the squadron saluted with a volley of guns. America was open. True, none of the team knew about this, Columbus himself did not suspect about his discovery, because until the end of his days he imagined that he had found only a new way to India. He also did not know that he had discovered and crossed the only sea on the planet without coasts.

This unique sea owes its existence to currents and wind. Off the coast of Africa, in the region of the Cape Verde Islands, a warm current originates, which is directed in a large circle towards America. It crosses the Atlantic Ocean a little north of the equator and bifurcates, bumping into the Antilles. Part of the waters of this equatorial current turns northwest along the ridge of islands, its jets merge with the warm waters of the Gulf Stream, and near Azores turn to the south, thus closing a wide ring. All floating objects, from chips to ships abandoned by the crew, once in this giant whirlpool, cannot go beyond its limits, which is clearly indicated by the paths of the remains of the ships, traced from the ships sent to tow or destroy them. The French geographer Camille Vallot reports that the schooner Fanny Walter traveled 14,000 kilometers in three years before sinking to the bottom. The ship "Fred Taylor", having described an exact circle across the ocean, broke into two parts at the border of warm and cold waters. Of the 230 ships abandoned by the crew between 1900 and 1907, none were swept outside the circle. Floating algae do not leave it either.

Columbus called what he crossed body of water"Grass Sea". Its modern name - Sargasso Sea - comes from the Portuguese word "sargasso" - a variety of small grapes. Brown algae with many spherical floats, apparently, reminded Portuguese sailors of grapes. Two species of these brown algae - floating sargassum and submerged sargassum - constantly drift on the surface of the sea that bears the same name. Plants of both species are devoid of attachment organs and represent a tangled mass. The wind drives individual clumps of algae into rafts and ridges, stretching one parallel to the other for many kilometers. Sometimes sargassums accumulate in such huge numbers that they form a continuous brown carpet, giving the ocean the appearance of a flooded bottomless swamp.

Sea currents do not have a strictly defined channel, they can deviate from the main direction either to the right or to the left. A sea without shores is constantly changing its shape, but only within certain limits. On average, it is located between 25 and 35 degrees north latitude and 40-75 degrees west longitude.

The basis of life in the Sargasso Sea is algae. They serve as a place of attachment for sessile marine organisms, herbivorous animals feed on them, fish and crustaceans, molluscs and worms find shelter in sargassums. Both types of sargassum cannot grow by attaching to the bottom, so animals of the sargassum biocenosis are not found anywhere outside their ever-swaying world.

Here they are born, grow, multiply and die. Over a long path of evolutionary development, all members of the Sargassum biocenosis adapted to each other, adapted to unusual living conditions in the ever-drifting thickets at the border of water and air. And the plants and animals of the Sargasso Sea cannot drown: they are all equipped with swim bladders, various cavities filled with gas. Mobile animals have tenacious paws or suckers with which they are held on algae. Non-motile organisms adhere to algae.

In animals of the Sargassum biocenosis, you will not find bright colors: they all wear a protective khaki uniform, often camouflaged in several tones. Lacy calcareous white colonies of bryozoans from the genus membranipore are attached to the algae. Accordingly, large Sargasso animals usually bear whitish spots. You have to peer into a lump of sargassum for a long time before you see a lurking crab or fish in it, so completely their color and shape merge with the background.

To get a closer look at the life of the Sargasso Sea, it is best to scoop up a large ball of algae with a net and place it in a wide basin with a bright bottom. Everything that was in the lump itself or in its vicinity will certainly end up in the basin. Even animals as mobile as fish, crabs or shrimps never try to get away from the net. On the contrary, at the slightest danger, they only get deeper into the algae and never want to part with it. Even those lumps of sargassum that are picked up from the water not with a net, but with a hook or an iron cat, get on board along with their population.

The Sargassum biocenosis includes about 60 species of various plants and animals. On the two main types of brown algae, the beaded red algae ceramium settles, forming small branched bushes. Some other types of small algae (red and green) also grow here.

Colonies of delicate hydroid polyps can only be seen with a magnifying glass. They feed on the smallest planktonic organisms, mainly the larvae of various animals of the biocenosis: the plankton of the Sargasso Sea is very poor in the spaces between the clumps of algae. The hydroids themselves serve as food for several species of small sea spiders and nudibranchs. The latter, like most members of the biocenosis, are brown-yellow or brown-green in color with whitish spots.

Of the nudibranch molluscs, a small scyllea, equipped with shaggy outgrowths, imitating the tips of the “leaves” of sargassum, attracts attention.

Among the algae, in search of food, small nautilograpsus crabs make their way, which, like the sargasso shrimp, are brown in color.

Large crabs of the genus Portunus swim boldly from one aggregation of Sargassum to another. They quickly overcome open space water and deftly hide in the saving thickets.

Special species of seahorses and sea needles also hide here. The needle-fish of the Sargasso Sea imitates the "stems" of algae with such accuracy that it can not be found even in an aquarium, although it is known that it is there. The large Sargasso clown fish, or Antenarius, has a striking appearance. The body of the clown fish is covered with many branched outgrowths resembling the tips of the sargassum. The fins of this fish are also ragged. Antennarius always keeps under the algae ball, into which he climbs at the slightest alarm. It is extremely interesting to watch this fish in an aquarium. While a bunch of sargassum floats on the surface of the water, the clownfish is almost motionless, it only slowly moves its fins along with the swaying tips of the algae. As soon as the sargassum is taken out of the vessel, the clown fish loses his temper. She rushes from wall to wall in search of shelter and does not calm down until the sargassum is put in place. The clownfish also breeds its offspring among the algae. She glues the “twigs” together, and as a result, a small nest is obtained, where the eggs are deposited.

The origin of the Sargassum biocenosis has not yet been fully elucidated. The initial assumption that the floating Sargassums were pieces of coastal seaweed turned out to be incorrect. off the coast of Africa, Antilles and on the coast of America, these species are absent. Yes, they cannot grow at the bottom, as they are deprived of attachment organs. The adaptation of these plants to life on the high seas could develop only over a long time - it indicates the long-term constancy of environmental conditions in the Sargasso Sea area. The population of the Sargasso originated, apparently, from accidentally introduced coastal littoral organisms. The peculiarity of conditions and long-term isolation contributed to the formation of new species that inhabit the world's only sea without coasts.

All seas have shores, certain outlines, to a greater or lesser extent delimited from the rest of the ocean by land, and communicate with it by straits. Two seas, both in our great country, and are completely closed by land, resembling lakes, these are the Caspian and the Aral Sea.
But there is on the globe such a section of the World Ocean, still called by geographers the sea, where there is no land at all, even along the edges - the sea is boundless, but not limitless, not boundless.
The borders, the edges of this boundless sea are sea ​​currents the northern half of the Atlantic Ocean, covering in an oval ring a vast expanse of water, devoid of any noticeable currents. Since the time of the great geographical discoveries at the turn of the 15th and 16th centuries AD, this part of the Atlantic Ocean has been called the Sargasso Sea.
"Sargaso" (small grapes) - the so-called Portuguese sailors of the Middle Ages, sea brown algae, studded with many spherical floats, abounding in a free-floating state on the surface of this part of the ocean. On an unnamed four-hundred-year-old globe, the Sargasso Sea is called in Latin "Grassy Sea". The word "grass" was used by Columbus, who discovered the Sargasso Sea during his first voyage in New World in September 1492. Columbus himself then assumed that these algae broke off from some nearby shallows. The crew of Columbus' ships were seriously frightened by the encounter with seaweed, thinking that there were dangerous reefs underneath.

Life at the surface of the Sargasso Sea

The experience of countless subsequent voyages soon dispelled the legend that there are so many algae in the Sargasso Sea that they are able to delay the ship.
Scientists for a long time could not solve the question of where the algae of the Sargasso Sea come from. Until now, many people think that they are carried there by the current, being torn off by waves from the shores of the West Indies, that is, the Antilles, the Bahamas, Cuba, Jamaica, from the Gulf of Mexico. For some time then they exist "in drift", "afloat", and then die off and sink. They drown because they are constantly overgrown with small marine animals with a calcareous external skeleton, and also because the dying sargasso lose the gas that maintains these algae in the water from their floats.
The sinking down into the oceanic depths of the dying Sargasso is certain here, but it is equally certain that the algae of the Sargasso Sea reproduce by offshoots, "budding" and are completely independent of the land.
The huge oval of the Sargasso Sea stretches approximately between 40° and 20° north latitude, extending from 70° to 30° west longitude. The length of this oval section of the ocean is approximately 5 thousand kilometers in latitude and 2 thousand kilometers in longitude.
The depth of the Sargasso Sea is very great, depths of 4-6 kilometers prevail, nowhere is the depth less than 2 kilometers.
The currents bordering the Sargasso Sea move anticyclonically, that is, clockwise. In the southern part of the sea, the North Equatorial Current tends to the west, on the western side the famous mighty Gulf Stream flows to the north in the form of the Caribbean and then the Florida streams, passing in the northwestern corner of the sea into the United Florida-Antilles stream.
In the north of the Sargasso Sea, the North Atlantic Current flows towards Europe, which is a continuation of the Gulf Stream, and from the east, the ring closes the weak Canary Current moving south.
According to observations over drifting bottles thrown to study the currents and over ships abandoned by the crew, but still not sunk, it turned out that these objects need from two to three years to go around the entire Sargasso Sea in the ring of its marginal currents. The exit from the ring-circle is most often the Gulf Stream - the most powerful and constant flow.
Currents in the ocean either weaken or intensify, move within fairly significant limits. These fluctuations depend both on the time of year and on the year in which we observe them. Accordingly, the boundaries of the Sargasso Sea are changing and fluctuating.
So, for example, by the end of summer - the beginning of autumn northern border The Sargasso Sea runs further north than in winter. The reason for this shift is that in summer it blows mainly southwest, and in winter - north or northwest wind, and that the Gulf Stream is most powerful in July-August.
The central part of the Sargasso Sea coincides with an area of ​​high air pressure - an anticyclone enclosed between the trade wind belt (to the south) and the westerly wind belt (to the north). The Sargasso Sea is therefore dominated by calm, weak variable winds and clear skies.
What is most significant for the Sargasso Sea, with its wavering, fickle outlines?
The point, of course, is not only that there are drifting sargasso, torn from the coast, they can come across in many places of the seas and oceans, a lot of sargasso is carried, for example, by Kuroshio in the Pacific Ocean, including in the Korea (Tsushima) Strait .
The most characteristic features of the Sargasso Sea: lack of constant currents, warm, salty, blue, exceptionally clear water, not torn off from the shore, but arising in the sea itself by budding from parent, gradually dying and sinking bushes, Sargasso algae with organisms living among them and on them.
The excitement, as a rule, in the Sargasso Sea is small. Accumulations of algae also prevent the wave from dispersing and growing. Warm calm water, weak wind caused the medieval name of this sea - "Ladies' Sea".
The beautiful deep blue color of the water of the Sargasso Sea competes with the blue of the sky over this sea. The blue is shaded, strengthened by yellowish-brown bushes of sargasso algae, sometimes scattered singly or in spots, sometimes meeting in fields and stripes. The size of the bushes is 20 - 40 centimeters. They only stick to the surface. On 1 square kilometer of the sea surface there is an average of 1 to 2 tons of sargasso algae or 10 - 20 thousand bushes, and on the surface of the entire sea there are about 12 - 15 million tons of algae.
Sargasso have never been observed to impede the progress of even a rowboat, which cannot be said about their distant relatives - giant kelp.
On the other hand, it is quite possible to wrap Sargassum algae on a lag or clog up seawater inlets that are not protected by a grate.
During the passage of our minesweepers across the Sargasso Sea from Kronstadt to Vladivostok, it was necessary to clear the logs from Sargassum algae; the same was observed in the first campaign from Leningrad to Vladivostok of the whaling queen "Aleut".
The algae inhabiting the Sargasso Sea are thermophilic, they quickly die at water temperatures below 18 degrees, and therefore they do not reach the shores of Europe in the flow of the North Atlantic Current.
50 - 60 species of plants and animals are commonly found on the surface of this sea. Some of them grow, stick to sargasso. Such are the beautiful bushes of the beaded red algae ceramium and the crusts, also red, but impregnated with lime, melobesia algae, calcareous branching rosary bushes of corallin algae, green filamentous algae, which forms shred-like fouling, some microscopic algae. Of the animals, several species of colonial hydroid polyps, some sea anemones, polychaete worms, lacy calcareous bryozoans-membranipores, "sea ducks" (lepas), colonial tunicate (ascidia) - diplosomas are inextricably linked with Sargassums. A tiny (several millimeters long) cochlea of ​​lithiope is peculiar, attaching to algae with thin transparent threads secreted by it; the length of these threads reaches a meter. We have already met such suspended, but large snails in the mangroves.
Attached to individual bushes of Sargasso, gluing them together and forming a kind of "nests", are clods of flying fish caviar.
Peculiar small yellow-brown crabs and shrimps of the same color, but with blue spots, ordinary amphipods and goat amphipods with a thin angular, “broken” body, equally thin “sea spiders” - pycnogons climb on sargassum, clinging to them, clinging to them. , several species of shellless snails. The most interesting, perhaps, are two types of fish disguised as "sargasso" - this is a pterophrine and a special seahorse. Pterofrine deftly climbs Sargasso with the help of pectoral and ventral fins that have turned into peculiar paws, her bizarre outline, awkward at first glance, brown body with blue spots hides perfectly among Sargasso; the pipit is no worse disguised, reddish-brown, with bright blue fins, covered with many outgrowths, clinging to the sargasso with its spirally coiled, resembling a twisted question mark tail.
Among the Sargassums, a sea needle swims freely, a large crab is an excellent swimmer - a portunus, sometimes even pursuing ships in pursuit of pieces of garbage from the galley. There are a lot of fast mackerels, hedgehog fish often swelling into a prickly ball, there is a triggerfish, the young individuals of which are disguised like shrimp, pterophrine, skates are disguised here. Every now and then, flying fish fly up and plan over the water. Clumsily, headlong away from the ship to the side and into the depths of large sea ​​turtles. Dolphins are frequent, and sperm whales come across. As if in a pond, water strider insects run on the surface of the water.
Siphonophores are interesting - complexly arranged jellyfish creatures with special swim bladders crowning their body; in a number of genera, for example, in the “Portuguese warship” - physalia or “sailboat” - velella * such bubbles protrude above the surface of the sea. Usually physalia and velella are found together.

Under the influence of the wind, the siphonophore bubble takes the most advantageous shape, representing largest area resistance. Until the wind reaches storm strength, until it, together with the wave spread by it, threatens to break, destroy the gelatinous body of the siphonophore, it enjoys the advantages of a fast drift, catching a large space with its long tentacles. And if the waves and the wind become dangerous, then the siphonophore "bleeds", releases an excess of gas that gives it buoyancy and sinks to a depth where the waves become not terrible. The siphonophores sink as soon as the pressure begins to drop noticeably, even before the start of the storm.
Even more interesting is another property of such siphonophores drifting with the wind and current: they have tentacles on only one side of the float. In calm and in the absence of a current, the tentacles hang down several meters from the float, and in moderate wind and current, the physalia extends them in the form of a plume almost horizontally. Then the physalia catches only a thin layer of water at the very surface, but on the other hand, on a large space, due to drift.
Among the Sargasso Sea, one can sometimes see a siphonophore, hopelessly, fatally entangled in algae. That this happens "sometimes" and not "often" is a consequence of the one-sidedness of the siphonophores and the deflecting force of the Earth's rotation, known as the Coriolis force, geophysicist.
In the northern hemisphere, the Coriolis force is directed to the right, and in accordance with this, the right flank of any flow in this hemisphere is stronger than the left, the level on the right side of the flow is higher than on the left, objects carried by the flow also accumulate to the right of the flow.
The asymmetry, one-sidedness of the siphonophore and serves to resist the Coriolis force. The siphonophores of the northern hemisphere are asymmetric in such a way that they deviate to the left under the pressure of the wind or current, and in the southern hemisphere they deviate to the right from the direction of the wind or current. At the same time, they, firstly, are less likely to get entangled in any debris (primarily in algae) that carries the current, and secondly, they have more chances to fall into areas where currents diverge, where deep waters rise to the surface, where there is more plankton and small fish, that is, where there is more food for siphonophores.
So, only quite recently understood by scientists who studied the laws of fluid motion, the structural features of siphonophores show the power of natural selection in the animal world. For many millions of years, the siphonophores most adapted to the conditions of water movement were selected and survived. The result of the selection is obvious.
The surface waters of the Sargasso Sea are very poor in small suspended organisms - plankton, which is why they are so transparent and blue. In the upper 200 meters of the water of the Sargasso Sea, plankton is 30 to 70 times less than in the cold Norwegian Sea. The reason for this is the poverty of the surface layer of the Sargasso Sea with nutrient salts of phosphorus and nitrogen; a lot of such salts accumulate as a result of the decay of dead organisms and the activity of bacteria.
In the southwestern and central parts In the Sargasso Sea, glassy-transparent flat larvae of the American and European river eels (the so-called leptocephali) can often be found near the surface. Here, at a depth of about 400 meters, in twilight, at a water temperature of 17 degrees, for the only time in their lives, eels coming here from afar, from the rivers of Europe and America, spawn. As they move away from these places, leptocephals become larger (from a centimeter above the breeding grounds to 6 - 7 centimeters before turning from a leptocephalus into a small eel). The eels go to the mouths of the rivers, from where their parents went on a campaign to the Sargasso Sea. Eels spend several years in the rivers, until the time comes for them to go in their turn to the Sargasso Sea; before that, the eels become big-eyed, as if preparing for the twilight of their former homeland and their future grave - the warm intermediate layers of the water of the Sargasso Sea.

Wanderings of the European eel

Scientists only half a century ago (in 1897) established that leptocephals are not a special breed of fish, as previously thought, but eel larvae.
At the depths of the Sargasso Sea, plankton is quite abundant and diverse, and the number of deep-sea fish, cephalopods, and shrimp is large compared to other parts of the ocean.
So, east of the Sargasso Sea, at a depth of 1,000 meters, 6-8 deep-sea luminous fish were caught in one catch - the “microtooth cycloton”, and not far away, but already in the Sargasso Sea, 90 and 448 of these fish were caught in two cases, while the same way of fishing.
Interestingly, some planktonic animals that inhabit the deep layers of the Sargasso Sea are common on the surface of the Norwegian Sea. Water temperature at great depths The Sargasso Sea is approximately the same as the surface temperature of the Norwegian Sea. There is a lot of food at the depths of the Sargasso Sea in the form of plant and partly animal remains. Examples of such planktonic animals are one crustacean - "Hyperborean Calanus" and a winged mollusk - "Clion Limacin", which is eaten by baleen whales in the north, where it lives near the surface.
What is the origin of the population surface water Sargasso Sea?
The nearest land is the West Indies, but the question of whether the Sargasso Sea Sargasso comes from the West Indian Sargassum or is it a completely different species has not yet been finally resolved.
Other animals and plants associated with the Sargasso in this sea also do not testify in favor of their Westindian origin.
Witty, but little substantiated by the facts, is the assumption of one scientist that the flora and fauna of the surface of the Sargasso Sea represent the “surfaced population” of shallow water, bordering the ancient sunken land of a kind of “Atlantis”, a mainland in the middle of the Atlantic that sank into the waters of the ocean, about which there were legends by the ancient Greeks. This assumption is also unfounded because the depths of the Sargasso Sea are too great.
Be that as it may, the “sea without shores” is one of the most peculiar and attractive areas of the world ocean, far from being fully explored not only in relation to its life-rich depths, but also to surface waters, which are also of great interest in relation to physical oceanography. The vertical and horizontal movements of water in the Sargasso Sea are still insufficiently studied and understood. West Side The Sargasso Sea differs significantly from the eastern one, and in the middle of the Sargasso Sea in the latitudinal direction there is a wavy boundary or a junction line of subtropical water masses (Gulf Stream) with the tropical waters of the North Equatorial Current, dividing the sea into northern and southern halves.

Introduction ................................................. ................................................. ................................................... 3
Chapter I. Biology of the sea and navigation .............................................. ................................................ 5
Chapter II. Living barriers .............................................................. ................................................. ................ thirty
Chapter III. Coral buildings .................................................................. ................................................. .... 42
Builder corals in tropical waters .............................................................. ............................................... 43
Form and origin of coral structures .............................................. ................................. 62
The practical significance of coral structures in the tropics.................................................................. ................. 70
Coral-like structures in high latitudes .............................................................. ............................. 81
Chapter IV. Forest on the border of the sea and land (mangroves) .............................................. ................................... 85
Chapter V. Seabirds .................................................. ................................................. ................... 92
Chapter VI. A sea without shores ............................................... ................................................. ........... 122
Chapter VII. Life in the depths of the ocean ............................................... ................................................. 133
Chapter VIII. Marine animals and sound .................................................. ................................................. 154
Chapter IX. Marine Drillers .................................................................. ................................................. ... 169
Chapter X. Marine fouling .......................................................... ................................................. ............. 182
Chapter XI. Dangerous marine animals ............................................................... ............................................. 191
Animals not allowed or dangerous to eat .............................................................. ......................................... 192
Marine animals poisonous on contact .............................................................. ......................... 193
Marine Predators .................................................................. ................................................. ............................... 209
Various other animals dangerous to humans .............................................................. ................................. 232
Electric fish .................................................................. ................................................. ......................... 239
Chapter XII. Harvest of the Sea.............................................. ................................................. ................... 244
Fishing ................................................................ ................................................. ...................................... 245
Whaling ................................................................ ................................................. ................................. 255
Sea animal .............................................................. ................................................. .................................... 261
Other marine animals ............................................................... ................................................. ................. 265
Seaweed................................................ ................................................. ...................... 274
Chapter XIII. How to Collect Collections of Marine Plants and Animals .............................................................. .. 276
Recommended Books ................................................................ ................................................. ....................... 287