Is there a sea that has no shores. What is a sea without shores

Who are the inhabitants bermuda triangle in the mysterious Sargasso Sea? The very heart of the giant whirlpool in the middle of the Atlantic is teeming with bizarre organisms, wandering eels, and…plastic debris.

text: Lars Abromeit

Everything is shaking. The steering wheel is trying to get out of hand. The sheets creak, the storm wind howls in the shrouds.

We went to sea on the training sailboat Corvit Kramer three days ago. A day later, the land disappeared from sight. To the very horizon - continuous waves of the Atlantic in foam "caps". Nothing to catch the eye. And there are still eleven days of sailing ahead. Our 41-meter brigantine, which the team affectionately calls "Mother Kramer", despite all the satellite navigators, emergency beacons and life rafts, seems like a helpless tiny sliver.

We are all alone 220 kilometers north of Puerto Rico, right in the middle of an amazing giant whirlpool in the Sargasso Sea. If someone gets sick, if a sail breaks, or if there is a fire, you can only rely on yourself.

At Sargasso Sea no shores. Its boundaries are not beaches or rocky reefs, but ocean currents. In the west - the Antilles, in the north - the warm Gulf Stream, in the east - the cold Canary Current. It carries water from the depths of the north west coast Africa and south of the Sargasso Sea passes into the North Equatorial Current. Together, these ocean currents twist into a huge spiral that rotates clockwise around Bermuda - the only piece of land within a radius of more than a thousand kilometers. Marine organisms carried by the currents can get stuck in this gigantic whirlpool for years, or even decades.

In the center of the spiral, a complete calm reigns for weeks, due to which sailors from sailing ships nicknamed this cursed place "a trap for lost souls." Christopher Columbus was the first to hit it in 1492 during his legendary voyage in search of western way to India. The languid calm got on his nerves. His companions feared that they were no longer destined to return to Spain.

The famous navigator was the first to describe the unique golden clusters of floating algae with green air bubbles at the ends of the branches. The Portuguese sailors who accompanied him called them "sargasso" - in honor of the small grape variety. It seemed to Columbus that they were in an enchanted place. Dense carpets of algae, birds, a strip of fog and whales clearly indicated the proximity of land. But there was no land. The compass needles danced like crazy, and at night the crew was frightened by a strange glow in the ocean.

Since then, there have been many legends about the Sargasso Sea and the Bermuda Triangle in its western part - with creepy ghost ships, floating islands and "space channels" through which extraterrestrial forces drag ships and planes into another dimension. This area of ​​the Atlantic between 45 and 75 degrees west really holds many secrets. Even for scientists. It is believed that sea turtles have been drifting in circles for years in the tangles of the Sargasso. A bizarre moonfish spawns here, and larvae and juveniles of swordfish, golden mackerel and marlin are unusually common. As well as dozens of species of whales. River eels swim thousands of kilometers from North America and Europe to find a mate in the Sargasso Sea and produce offspring.

Who else lives here? Has our civilization reached these distances? And if so, how did it affect the local ecosystem?

The members of the expedition organized by the Woods Hole Oceanographic Institute (Massachusetts, USA) are trying to answer these questions. Goal of a team of 37 specialists: to sail from the eastern border caribbean more than one thousand miles towards Bermuda - and all the way to New York to study the flora and fauna high seas.

In addition, the expedition also has an educational mission. Professor of Oceanography Amy Siuda of the Association for Maritime Education at Woods Hole (USA) took fourteen students with her.
Their task is to study the accumulations of Sargasso with their inhabitants floating on the surface of the sea, as well as particles of garbage.

Ambitious project. Firstly, the area that the expedition members are going to comb in the open sea is comparable in size to the territory of the European Union. Secondly, the Sargasso Sea is fraught with many dangers. There are huge depths here - under the keel of our sailboat now would easily fit highest peaks Alps. And unpredictable weather, which at one time almost drove Columbus to despair.

But our "Admiral" Amy Siuda is not afraid of the vagaries of the Sargasso Sea. She has been throwing her "net" into it for 17 years.

The guys from the “A” team, after a night watch, fall exhausted into their beds. Ten o'clock in the morning. Among the waves, the first bunches of sargasso are already flashing. It's time for us to work.

Amy Siuda in her final months of pregnancy. But this does not prevent her from commanding her students. With the help of a winch, they lower three nets overboard, with which they will trawl the sea: one at a depth of 70 meters, the other at 150 meters, and the third at the very surface. Where the Sargasso drift.

The researchers are bringing dozens of beams aboard. Each of them is a miniature forest in which life is seething. Branches of algae are covered with tiny cnidarians and barnacles. Drifting across the sea in their houseboats they eat plankton. Poisonous slugs swarm among the air bubbles on the stems. Their golden coloration is the perfect camouflage. Predatory shrimp smaller than a fingernail search for prey in dense thickets. In one of the bunches, even a Sargasso sea clown hid, tightly clinging to the branches with its pectoral fins. He changes color like a chameleon, explains Siuda. And he hunts from ambush for small fish or his relatives.

More than 140 species of invertebrates and 127 species of fish find food and shelter in the Sargasso. Ten of them, including anglerfish, needlefish, crustaceans, snails and sea anemones, spend their whole lives in them. Others look into the Sargasso in passing. For example, flying fish, twisting "nests" of bubble caviar under their canopy. Large migratory species such as tuna or sailfish come here to hunt. And it is here, as we managed to find out with the help of radio beacons, that sea turtles spend the first years of their lives. Algae carpets provide them with reliable protection. In addition, the water in the Sargasso is several degrees warmer than in the open sea, which contributes to the growth of reptiles. Birds also visit the floating islands - typhoons, terns and boobies feed and rest in the Sargasso Sea during transatlantic flights.

In the ecosystem of the open sea, sargasso act as "mini-incubators". But about the algae themselves, which about 40 million years ago separated from their coastal relatives and went into free swimming, surprisingly little is known.

There are two types of them: floating sargassum and submerged sargassum. The first has smaller leaf plates, the second has larger ones. But do they differ from each other in the species composition of their inhabitants? And on what routes do they drift across the sea?

“The only reliable source of information about these algae is from the Marine Education Association expeditions,” says Siuda. “For the past 20 years, they have been the only ones who have been making regular observations in the Sargasso Sea.” The conclusion of the participants of these expeditions is unequivocal: two species of Sargassum algae form the same different ecosystems as coniferous and deciduous forests. And they are inhabited by different organisms. Swimming Sargassums seem to have been drifting with the current for years all the way to the straits of the Caribbean Sea. And the submerged slowly move within the southern part of the Sargasso Sea. But why?

"It's hard to say," Siuda replies, unraveling the tangles of seaweed. Scientific data is still insufficient, and it is extremely difficult to collect them.

First hour of the night. The port of St. George in Bermuda is about 500 nautical miles away. The excitement finally stopped. On the sea, only a slight swell.

In the laboratory cabin, plankton researchers evaluate the evening's catch. Siuda is distributing the captured eel larvae to the students, who are to take tissue samples for DNA analysis. Under the microscope, leptocephalic larvae look like ghosts: a completely transparent flattened body, a tiny head with a mouth bristling with sharp teeth. They have so little in common with adult eels that for a long time scientists considered them to be a separate species.

Our team already has about 300 larvae. Most belong to the conger family - these are conger eels. But there are also several larvae of the river eel among them. For explorers, these are real treasures. Perhaps they will provide clues to one of the biggest mysteries of marine biology: where exactly do European eels come from?

Disputes about this have been going on since antiquity. Fish similar to snakes are born from bottom silt, Aristotle believed. No, they multiply by rubbing against rocks, Pliny the Elder assured. Eels hatch from drops of morning dew, Isaac Walton, author of The Artful Angler, argued authoritatively in the 17th century.

Today, all evidence points to American and European river eels swimming to the Sargasso Sea, where they mate, spawn, and then die. In any case, it was here, south of Bermuda, that the youngest eel larvae were found. But decisive evidence is lacking. They could be eel caviar. Or a photo of a mating pair. Or at least the corpse of an adult eel from the depths of the sea. Any such find would be a sensation.

But for now, biologists have to be content with hypotheses. Presumably, during migration, eels are guided by ocean fronts - the boundaries between two water masses with different temperature, chemical, or dynamic characteristics. And possibly the earth's magnetic field. So they swim more than 6,000 kilometers - from the coast of Europe across the Atlantic. At some point, they find their "half". And their larvae drift along the Gulf Stream back to Europe.

But why such difficulties? So far there is no answer to this question. It is possible that this is just an atavism. Eels may have spawned in the Sargasso Sea region 130 million years ago, when the continents were closer together. Or maybe it's all about the abundance of algae. Flat larvae have plenty of nutritious “sea snow” here - particles of dead algae that stick together with the secretions of planktonic organisms and rise to the surface with air bubbles at night.

All these are just hypotheses, but the example of the eel shows how complex the ecosystem of the open sea is organized. It is permeated with a whole network of migration routes, along which even fragile eel larvae can get alive and healthy from the Sargasso Sea to the rivers of Europe.

Ocean routes depend on natural elements. The Gulf Stream alone pumps every second 150 times more water than all the rivers of the earth combined. Short-term water eddies push cold masses of water saturated with nutrients from the depths to the surface. And in the middle of the Sargasso Sea, blooming oases suddenly appear, where there are almost 100 thousand times more planktonic diatoms than in neighboring water areas. This oceanic "desert" produces every year three times more plant biomass than its equal size Bering Sea, which is considered very "fertile".

But sea currents are not very picky. Along with sargassum, plankton and eel larvae, they carry garbage from our cities into the open sea. Millions of tons of garbage enter the seas every year (see infographic on page 40). Only a small part of it is visible from the Corvit Cramer: plastic bottles, pieces of foam. But on the net it comes across in frightening quantities: up to 200 plastic fragments in half an hour.

Basically it is the so-called "microplastic". Multi-colored particles smaller than five millimeters make up 90 percent of the plastic debris drifting across the oceans.

The spread of microplastics in the oceans is one of the most serious environmental issues modernity, experts say. Microparticles, like magnets, attract and accumulate toxins, carcinogenic chloride compounds and heavy metals. Then they are absorbed by the smallest filter feeders: copepods, planktonic larvae, salps, molluscs and fish fry. And in the end, having passed through the food chain, they return to people again.

In addition, microplastics carry disease-causing viruses and bacteria through the oceans. What exactly? This is what Siuda is trying to establish together with microbiologist Will Mellvin. Back in 2013, their colleagues were able to prove that more than a thousand species of bacteria live on individual microplastic particles in the Sargasso Sea. Some of these nomadic communities are dominated by bacteria of the genus, a group of microbes that includes cholera pathogens and deadly nerve poison generators. Thus, under the cover of the sea, a completely new ecosystem is formed. Siuda calls it the "plasticosphere".

On the fourteenth day of sailing, land finally appears on the horizon: Bermuda. But a nine-point storm that has flown in from the north makes us “dance” on the waves for another thirty hours, writhing in bouts of seasickness.

Flaming sunrises, thunder of the storm endless expanses- the sea does not skimp on grandiose spectacles. But at the end of the voyage, only one prosaic detail remains in the memory: two hundred plastic particles in a small test tube with sea water.

Will the day come when there will be as many garbage patches in the Sargasso Sea as islands of algae? Who will prevent this ecological apocalypse? The Sargasso Sea is outside state borders, and protect it based on international law very difficult. Moreover, even the status of a marine protected area will still not protect it from plastic debris: it is known that sea currents can carry a piece of plastic across the Atlantic in just a few weeks.

In 2010, American scientists tried to assess the possible damage from the "plasticosphere". As they moved east from Bermuda, they recorded up to 26 million microplastic particles per square kilometer- this roughly corresponds to the concentration of plankton. Scientists have suggested that after a couple of miles this figure may increase.

But they failed to verify their guess: they had too little time, and the sea turned out to be too large.

Sea without shores

Look at physical map: open spaces Atlantic Ocean, closer to the mainland of North America, between 20° and 40° N. sh. have the shape of a giant ellipse of light green color. This is a one-of-a-kind miracle of nature - the SARGASS SEA, the shores of which are not land, as usual, but large oceanic rivers-currents: in the west and north - North Atlantic, in the east - canary, on South - trade wind, moving around in a clockwise direction.

Acting as a kind of watersheds or dams, the currents do not allow surface water to Sargasso Sea mix with colder waters North Atlantic.

But, unlike ordinary land shores that limit the seas, these water "shores" due to the inconsistency of sea currents undergo significant movements at different times of the year, that is, they "travel". Therefore, the area Sargasso Sea varies from 8.5 to 4 million square meters. km.

The huge oval of the Sargasso Sea stretches for 5,000 km from west to east and 2,000 km from north to south.

Another feature Sargasso Sea is that it, like a gigantic meadow flooded in the midst of the ocean, is covered with such a quantity of floating seaweed as is not found anywhere else on the globe. One to two tons per square kilometer of sea surface! Christopher Columbus who discovered this sea on his way to America September 16, 1492 called him "seaweed jar" Interestingly, all these algae belong to the same species. First Portuguese sailors They called them "sargasso", because the air bubbles that help the algae move and stay on the water are similar to the grape variety common in Portugal.

Sargassum algae lead a planktonic lifestyle. Scientists long time couldn't decide where they came from. Until recently, it was believed that they were brought by currents from the shores of the Antilles and Bahamas, Cuba or from the coast of the Gulf of Mexico. But it turned out that they are born here, live and die. When the plants die, the bubbles burst and the browned algae sink into the ocean depths.

Sargasso algae, like a forest, are densely populated with various living creatures: shrimps, crabs, numerous species of fish, especially mackerel, the so-called flying Sargasso fish, etc.

surface water Sargasso Sea There are about 60 species of flora and fauna. They are poor in plankton, and therefore very transparent. Due to the insignificant movement, the water in the sea is more salty than the surrounding ocean. It is bright blue and one of the most transparent in comparison with the water of all the seas. The water temperature here is also always much higher than in the ocean, and ranges from 18–23°C in January to 21–28°C in July. This is what favors the rapid development of seaweed.

Depth Sargasso Sea reaches 4–7 km. It is located in a zone of high atmospheric pressure, therefore, calm prevails here, which in the era of the sailing fleet often led to the death of ships. Due to the fact that they often carried domestic animals, mainly horses, which were transported from Europe to the American colonies, the latter died in especially large numbers, and the corpses were usually thrown overboard. Hence the name of this area of ​​\u200b\u200bthe ocean - "horse latitudes".

Another one unique feature sea ​​is that it is the cradle of freshwater eels. Sailing in the summer to spawn from the rivers of Europe and America, they die after it ends, and their descendants, using some mysterious landmarks known only to them, overcoming many thousands of kilometers, return exactly to the places where their parents sailed from (so far an incomprehensible mystery for scientists) in order to return here in 8–9 years, spawn and die.

For the predominance of calm weather Sargasso Sea also called "ladies", and for a large number of algae - "herbal". However, the sea only at first glance seems calm. In 1970, Soviet oceanographers discovered here powerful upward movements of water from great depths, the so-called vortices. It has been established that they affect the increase and decrease in sea water temperatures. The sea, in addition, significantly affects the circulation of water. North Atlantic and the climate of the entire northern hemisphere of our planet.

The Sargasso Sea is located in the Atlantic Ocean. But this is not the sea in the truest sense of the word. Any salty body of water is limited by the coastline. In this case, there are no shores. 4 Atlantic currents bend around a huge mass of water and make it rotate clockwise.

In the west, the Gulf Stream passes and rushes to the northeast. Further, the North Atlantic Current moves in a northeasterly direction. From the east, the slowly rotating waters are supported by the Canary Current, which carries its waters from the western coast of Africa to South America. And in the south, the North Equatorial Current creates an invisible border.

The area of ​​\u200b\u200bthe reservoir that has no boundaries is approximately 5 million square meters. km. West to East length exotic sea is 3200 km, and from north to south reaches 1100 km. But these values ​​are not constant. They fluctuate depending on the position of the currents. In coordinates, the water mass is located between 20-35 degrees N. sh. and 40-70 degrees W. e. The Bermuda Islands are located in the northwestern part of this water area.

The water in the sea has a rich blue color, and its transparency is 60 meters. Temperature surface water high. IN winter period it is equal to 20-23 degrees Celsius, in summer it rises to 26-28 degrees Celsius. The salinity of the water corresponds to 37 ppm. The depth of the reservoir is more than 6 km, and the maximum value reaches 6995 meters.

The sea is characterized by a huge accumulation of floating brown algae - Sargasso. Experts estimate their number on the water surface at 10 million tons. In some places, algae completely cover the water, and in some places there are spaces free from them. For ships, these natural formations do not pose any danger.

Their accumulation in the Sargasso Sea is due to surface sea ​​currents converging at this location. They bring algae from all over the ocean, and once they get into the slowly rotating waters, they create a special biological world with a unique fauna.

Historical reference

The water covered with algae was known even to the Carthaginians, who sailed to Azores. This period dates back to the 5th century BC. e. and is associated with the name of the Carthaginian navigator Himilko (Chimilkat). Examining the northern waters of the Atlantic, he also mentioned algae.

For the first time, Christopher Columbus crossed the Sargasso waters in 1492. Great Navigator was struck by a huge accumulation of algae in ocean water. After Columbus, other sailors on sailing ships also visited these waters. Sometimes they complained about light winds characteristic of these latitudes. But no mysterious incidents and disappearances were observed in these exotic waters.

Sargasso Sea on the map

Fauna

Warm water attracts American and European eels to spawn. These waters have chosen for themselves and young sea turtles. They live in them until they become adults. This is explained by the fact that large marine predators do not like water covered with sargasso, so it is an excellent protection not only for sea turtles, but also for many species of fish that have chosen it for spawning.

IN warm waters flying fish live. Thanks to their large pectoral fins, they are able to jump out of the water and soar in the air for a short time. But sea needles are kept perpendicular in algae and their appearance similar to their offshoots. Lots of sea anemones, bryozoans, crabs.

The Sargassum sea clown is widespread. It belongs to the family of sea devils and feels comfortable in sargasso thickets. Its color completely coincides with the color of algae, so it is almost impossible to see this ray-finned fish. But holoplankton does not live in this region due to the too high water temperature.

Ecology

Everything would be fine if the Sargasso Sea was not included in the zone of the North Atlantic garbage patch. This is plastic and other artificial waste floating in sea ​​water. The spot was discovered for the first time in 1972. Since then, it has grown noticeably in size. At present, it stretches for hundreds of kilometers, and its density is 200 thousand objects and debris per 1 sq. km. km.

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 of North America and the underwater elevation of the arc of the West Indies, where depths of more than 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. The largest islands are 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. main reason the appearance of rumors about aliens consider 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