Extracurricular activity for primary schoolchildren “Why is the Sargasso Sea without shores? Sea without shores Sargasso Sea why without shores

Did you know that there are seas without shores or borders? Where mirages live constantly and the sun rises on both sides?

the site knows a lot of strange and interesting things about this mysterious sea.

On our planet there is a boundless sea that has no solid coastline. It is located in Atlantic Ocean, in the Bermuda Triangle area, and is clearly visible from space.

In this place you can observe unusual mirages with a split moon. Simultaneous sunrise from two opposite sides. Ghost ships gliding across the water surface. Giant disks “pop up” from the depths.

Sea in the ocean

Mysterious sea on Earth

The area of ​​this mysterious reservoir is about 6 million km 2. Due to the lack of solid banks and instability of currents, it is constantly changing, sometimes increasing and sometimes decreasing. Maximum depth reaches 7 thousand meters. IN summer period The water temperature is 26-28 o, in the cold season it does not fall below 16-18 o.

This transparency indicator is higher than in the Red Sea, which is considered the cleanest on our planet. In many places the surface is covered with accumulations of brown algae.

Life in the Sargasso Sea

Fauna of the Sargasso Sea

In the sea, at its bottom, bush-like sargassum algae grows. When they break away from the bush, they float to the top and are held on the surface of the water thanks to air bubbles. It is a natural pasture for 60 species sea ​​creatures Sargasso Sea - sea turtles, shrimp, crabs, flying fish, etc. But large predators I don’t like this place, they only swim here occasionally.

If you frighten him, he begins to quickly swallow water, swelling and increasing in size to a spherical state.

Eel fish

But what is most striking is the behavior of the European eel. For a long time, the place where they spawn was a mystery to humans. And only in the last century it was discovered that in order to reproduce, they travel to the Sargasso Sea, thousands of kilometers from their habitat.

Behavior of the European eel

History of the name of the sea

What do the name of the sea and wild Portuguese grapes have in common? It turns out that it got its name thanks to this plant.

When in 1492 the navigator Columbus found himself in these waters, covered with algae with some kind of “berries”, they reminded him and the entire crew of sailors of bunches of grapes in their homeland. Its name was Sargazo, they called the algae that way and this place was the Sargasso Sea.

It later turned out that the “berries” are just a collection of air bubbles at the ends of the plant. They support them on the surface of the water. For sailboats of past centuries, these algae represented mortal danger. There was no way to get out of the insidious trap in complete calm.

Calm weather in these places can last for several months. The sailors of the sailing ships became eternal hostages of the sea and died of hunger and thirst.

Marine Graveyard

The proximity of the mysterious Bermuda Triangle adds to the mystery.

Mysterious sea without borders and shores

Surviving witnesses are reluctant to say that in the midst of complete calm and cloudless sky it suddenly began. And soon, just as suddenly, silence came, and the surface of the water was in a foggy haze. The entire crew of the ship disappeared without a trace, but everything valuable and the lifeboats remained in place.

Ecology

A huge floating island was formed from the debris on it. It was first discovered in 1972. And every year its size increases, occupying hundreds of kilometers of water surface.

Video: Mysterious sea without shores

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Large expanses of the Atlantic Ocean, closer to the mainland North America, between 20 and 40 gr. With. w. have the shape of a giant ellipse of light green color. This is a one-of-a-kind miracle of nature - the Sargasso Sea, the shores of which are not land, as usual, but large ocean currents: in the west and north - the North Atlantic, in the east - the Canary Sea, in the south - the Trade Wind, moving in a circular clockwise direction.

Acting as a kind of watershed or dam, the currents prevent the surface waters of the Sargasso Sea from mixing with the colder waters of the North Atlantic. But unlike ordinary land shores that limit the seas, these water “shores”, due to the inconstancy of sea currents at different times of the year, undergo significant movements, that is, they “travel”. Therefore, the area of ​​the Sargasso Sea varies from 8.5 to 4 million square meters. km.

This led to the accumulation of plants called Sargassum algae on the surface of the ocean. These large, up to two meters, yellow-brown plants belong to brown algae, but, unlike their relatives, they are able to live and reproduce afloat, without attaching to anything. The first Portuguese sailors called them "sargasso" because the air bubbles that allow the algae to move and float are similar to a grape variety common in Portugal.

The Sargasso Sea is a unique world inhabited by many species of worms, mollusks, crabs and fish. Very peculiar water striders live there. Some of them are not found anywhere else. Many of these inhabitants of the open ocean are very poor swimmers or do not know how to swim at all. But this is not a mandatory requirement for life. Why swim when there are thickets all around that you can walk through?

The unusual nature of the Sargasso Sea has given rise to many legends. The most tenacious one talks about the existence of such accumulations of algae there that ships get stuck in them and die. The legend is still repeated from time to time, despite the fact that sailors never complain about the occurrence of any complications when crossing the sea.

However, sailing ships of past centuries actually got stuck in the center of the Sargasso Sea. But not because of the algae, but because of the eternal calms. Sometimes I had to stand for an infinitely long time. Galleon crews were forced to throw riding horses overboard to save supplies drinking water. Unlucky horses could survive for months by staying afloat and eating algae. Sailors from passing ships often saw strange creatures floundering in a tangle of algae with maddened horse snoring, rotting alive under the scorching sun. That is why the Sargasso Sea in past centuries was also called “horse latitudes”.

As a rule, a small space in the ocean, which is framed by islands and continental shores, receives the status of a sea. However, the exception is the Sargasso Sea, since it has no shores at all. This kind of “sea without shores” is located in the west of the Atlantic Ocean. Unlike other seas, the Sargasso Sea is distinguished by unique water properties, amazing tranquility and characteristics of the living population, this cannot be found in the waters of the Atlantic. Such differences are facilitated by the circulation of currents, which runs clockwise, creating peculiar boundaries in the sea.

Today, the Sargasso Sea remains a mysterious place for humanity. In the Middle Ages there was an unkind rumor about him. And the reason is that a significant part of the maritime territory is located in the Bermuda Triangle, which is located in the southwest of the Atlantic Sea. In addition, the Sargasso Sea is considered the only sea of ​​its kind that has no boundaries on land. From all its borders, the Sargasso Sea is repulsed by strong currents, including the Gulf Stream. Also in this zone of the World Ocean there are strong thickets of algae, which, floating on the surface of the sea, resemble islands of land. Such islands sometimes circle in place, but it seems that sea ​​water here it is motionless, because they move very slowly.

Another mystery of the Sargasso Sea is the year-round calm, windless weather. Therefore, this sea has a bad reputation; it is called a ship graveyard. Medieval sailing ships stopped when they became calm, and it was impossible to row manually due to algae. For this reason, the sailors relied on the appearance of the wind or slowly died.

Interestingly, only algae grows in the Sargasso Sea, but their quantity is sufficient for most small fish and other living creatures that live and feed among them. Many fish choose these waters for breeding because of the warmth, salinity and cleanliness.

Inhabitants of the Sargasso Sea

It is the Sargasso Sea that is called the homeland of eels, which live in the Atlantic Sea basin. Eels swim here to spawn, but they don’t come back from here. Eel larvae hatch in local waters, and then the fry develop. Adults travel to Europe.

Science fiction writers appreciated this interesting natural object. Edward Hamilton, Jules Verne, Warner Munn, Andre Norton and many others often used Sargassum seaweed or the Sargasso Sea theme in their works.

It is noteworthy that almost all living creatures of the Sargasso society differ in color and shape, which is hidden in the algae. The fish resemble twigs and leaves, and their body color has yellow-brown shades, which perfectly camouflage them. It's hard to see among the sargassum branches seahorse. The Sargassum clownfish also camouflages itself - its body resembles a sargassum branch.

Most people are familiar with the breeding history of the European eel in the Sargasso Sea. After all, for hundreds of years no one knew where exactly this fish reproduces. This has been the centuries-old mystery of the Sargasso Sea. It is interesting that they create offspring in its waters, then return here to die in its abyss. Such loyalty to the homeland is an amazing development among the fishing community.

A little more about the inhabitants

It is noteworthy that it was thanks to eels that scientists were able to detect currents at significant depths in the ocean, because this is where the fish go. The discovered current is the opposite of the Gulf Stream, which is why it received the name Anti-Gulf Stream. Thanks to this current, the eels return to their spawning grounds. The story about eels can be continued endlessly; the American eel from North America spawns in another region of this sea, and uses a certain branch of the current as a passing transport to rivers and American shores.

The inhabitants of the Sargasso Sea are sea ​​turtles who saved sailors during calm periods. These wonderful turtles eat algae. Jellyfish and invertebrate animals are also found here. Even sharks are found in this unusual sea, mainly: pelagic sharks, blue sharks, silkies and makos. Almost no one swims in this sea, so sharks do not pose a danger to people.

This unique sea is located in the North Atlantic - between the West Indies and Bermuda. It has no shores, since it is limited not by the earth’s surface, but by ocean currents - the Gulf Stream in the west, the North Equatorial in the south and the Canary in the east. We are talking, as you probably understand, about the Sargasso Sea.

This sea is distinguished by its unusually calm disposition - not only of storms, but even strong winds doesn't happen there. They say that if you put a burning candle on the deck of a ship in the Sargasso Sea, it will not go out until it burns out completely. The fact is that in those parts there is a constant anticyclone, which creates an area above the sea high pressure. It was this cyclone that the sailors of past centuries “thanked” for the constant calm. Sailboats drifted for weeks on ominous waters, waiting for at least a faint breath of wind. It happened that a team left without food and drink died. That is why the Sargasso Sea is still called the graveyard of ships.

Sargasso Sea - ship graveyard

Ancient sailors also wrote in ship's journals about gigantic, unexpected whirlpools that could suck in passing ships. These craters appeared no matter what the weather was like. Perhaps the reason for the occurrence of such whirlpools is warm Atlantic currents.

But constant calm and colossal whirlpools were not the only danger that awaited the sailors. The ships of Christopher Columbus, who, by the way, discovered this sea, had difficulty crossing it also because its water area was literally covered with algae. Similar to bunches of grapes, they float everywhere, preventing the passage of ships. Actually, the sea got its name precisely because of these algae, which resemble bunches of grapes (from the Portuguese - sargaco).

According to rough estimates, there are up to 11 million tons of algae in the Sargasso Sea. If earlier sailors were terrified of being captured by sargassum, which, wound around the propeller, did not allow the ship to move, then modern ships are not afraid of them. What’s much worse is that the once fairly clean (transparency up to 60 meters) sea water is now polluted with fuel oil.

Incredible Journey

However, these circumstances do not threaten shipping, but the numerous inhabitants of the Sargasso Sea, because flying fish, crabs, and sea turtles live in its warm, almost stagnant water.

But the eel that lives in freshwater bodies of Europe suffers the most from water pollution. This amazing fish makes an incredible journey to the Sargasso Sea in order to descend to a depth of 1200 meters, give birth to offspring, and then die.

It must be said that another ancient sage, Aristotle, believed that eels spontaneously generate in swamps or come from earthworms. This misconception lasted until the 16th century, when scientists finally traced the migration routes of eels.

Having reached the age of seven, these snake-like fish move along streams and rivers towards the Atlantic. They can cover a distance of more than five thousand kilometers in 80 days. Once in a body of water that does not have access to the sea, eels are able to climb ashore in order to find a water stream along which they will get to the sea. After laying eggs in the sea, the eggs die. The fry, which develop from the eggs, are picked up by the Gulf Stream and carried to the east. The journey to the European coast takes approximately 2.5 years for the younger generation.

It turns out that defining such a seemingly simple concept as the sea is not at all easy. There is no generally accepted definition, which means there is no generally accepted classification of seas either.

The sea is usually defined as a large part of the world's oceans, which in some ways differs from this ocean itself. The sea has its own special climatic, hydrological and meteorological regime due to the fact that for some reason the free exchange of water between the sea and the “open” ocean slows down. Most often, this is due to the configuration of the seashore or the rise of the underwater relief to the surface of the water. Thus, the Sea of ​​Azov is connected to the Atlantic Ocean through the Black and Mediterranean Sea, but the salinity of the water here and the fauna and flora are significantly different from those in the ocean. The border between Aegean Sea and Mediterranean are defined very conditionally along the line connecting the islands of Crete, Karpathos and Rhodes. It is difficult to determine the difference between these seas if you are not an expert.

And immediately everyone who has studied geography remembers the seas that are not connected to the ocean: the Caspian, the Aral, the Dead... They do not fit the above definition, but are considered seas. But neither Baikal nor Lake Kinneret, located very close to Dead Sea, for some reason they are not considered as such.

Another exception to the seemingly strict definition is a sea without shores. Yes, there is such a thing. It is called the Sargasso Sea and is located in the Atlantic Ocean off the coast of America. At its northwestern tip are Bermuda. Christopher Columbus discovered it on his voyage, before reaching the shores of America. At some point, the sea water on which his caravels floated became motionless and became covered with many plants. In addition, at that moment the wind disappeared. It seemed to the sailors that these plants clung to the sides of their boats and did not allow them to sail further. "We are dead!" - was the first thought. In addition, at night the sailors saw a large starfall in the sky, which was also interpreted as a sign of trouble. God knows what could have happened next if Columbus had not ordered the oars to get away from both the calm and the strange water covered with algae. A few days later the wind blew and a current appeared. Soon the sailor on watch saw the islands. This marked the end of a glorious journey that, without exaggeration, changed the course of world history.

Columbus, of course, marked a strange place on the map. But it was studied later. And the sea received its name later. It was named Sargasso after the algae that covered the entire water surface here. Portuguese sailors called these algae "sargassum", "small grapes".

But why does this sea exist without shores? What limits it from other ocean waters? What makes the waters of the Sargasso Sea different from other waters of the Atlantic Ocean?

The answer is: underwater currents. The Sargasso Sea region is bounded on all sides by Atlantic currents. In the west it is - warm current Gulf Stream, in the north - North Atlantic Current. In the east, the waters of the Sargasso Sea are limited by the Canary Current, and in the south by the North Trade Wind Current. It was this latter that urged Columbus's ships at the beginning of his journey across the open ocean. In general, these four currents form Roundabout Circulation ocean waters clockwise.

As always, if water begins to move in a circle, a place is formed in the center where it is motionless. This is the Sargasso Sea. It is precisely because the surface layer of water here is motionless that the Sargas rise to the surface and form a huge “carpet”. This "carpet" is visible even from space. Space stations and satellites have repeatedly photographed the surface of the Sargasso Sea for biological research.

Unfortunately, they photographed him for other purposes as well. The fact is that the circular current, as if forming the “shores” of the Sargasso Sea, sucks from the outer ocean all kinds of light debris floating on the surface of the Atlantic in tropical latitudes. Almost one hundred percent of this garbage consists of plastic bottles and boxes. The laws of nature cannot be fooled - all the garbage, swirling in a circular current, slowing down its movement, gradually moves towards the center of the Sargasso Sea, where, stopping, it forms huge spots of plastic waste. Because the