The Black Sea glows at night. Glow of the Black and Azov seas in the Crimea. The glow of the sea and its causes

At night, there are both phyto- and zooplankton near our coast - everything is mixed in shallow water. And most plankters are able to glow in the dark. This is one of the most joyful - for us - their properties. Chemically, the glow reaction of marine organisms is exactly the same as that of firefly beetles, which we admire on warm summer nights on the coast. Substance - luciferin (light carrier - Greek) is oxidized by oxygen under the action of an enzyme luciferase . Most chemical reactions release heat, but this one releases one quantum of green light.

From July to the end of September. But the most best time- from the beginning of August to the beginning of September - the first weeks of the summer-autumn development of plankton.

Already approaching the dark water, we see that a weak surf shakes pieces of greenish light on the sand - feel them with your hands - they are slippery, they melt on your fingers. It was the waves that washed the ctenophores to the shore, they have already been smashed against the sand, but they continue to glow. Shake them off your hands - and the light will remain on the palms - even smaller pieces of the delicate bodies of sea creatures stuck, remained on your skin. If we walk along the edge of the surf, we will find small, constantly luminous points on the sand - we will pick them up and try to examine them. These are amphipods, sea fleas - but already dead, they do not jump, like those that we chased during the day. These crustaceans have already begun to be eaten, decomposed, by bacteria that always glow - rotten ones glow in the same way. Why do planktonic organisms glow? Let's wait for the night and answer this question ourselves. The darker the night, the better - the flashes of living light in the sea will become more noticeable. And, of course, the sea must be calm - otherwise we will not see anything. In general, the night should be quiet, dark and warm. There are many such on our shore - from the beginning and in the night forest. Do not be afraid - admire, this is also life. Amphipods have a lot of microscopic spines on their shells - we have already seen them - these spines will allow you to attach a glowing badge to your shirt - just press the crustacean to the fabric.

We will enter the dark clear water from the familiar beach - by touch. On a summer night, the sea is warmer than the air above it, you can swim without feeling the water - they usually talk about this - like fresh milk! - but night is night - and, perhaps, it is worth once again reminding you of caution - you should not swim where you cannot get to the bottom.

Let's slowly, without splashing, step from the shore and look at our feet. And the legs are glowing! These are tireless plankters - mobile algae, crustaceans - collide with our skin and flash with emerald light, there are so many of them that the bodies of people moving in the water become emerald. When there is really a lot of plankton, you can watch an amazing sight - floating luminous person. He dives - and shines brightly under water, and leaves a sparkling trail behind him.

Rarely, but - there is such luck - you manage to see the games of dolphins blazing with green fire! And if you go out to sea at such a time in a boat, the oars seem to be burning - and with each stroke they break off and remain behind, circling and wriggling, tongues of green flame.

Such an even, strong glow, in which no individual flashes are visible, is caused by planktonic dinoflagellates - they are most abundant in warm water. Diatoms cannot glow. Any movement we make in the water causes radiance and flashes. Radiance is a lot of small flashes of microalgae, merging into a single glow - there are so many of them. And separate bright green lights are flashes of irritated planktonic crustaceans. Sprinkle water - green sparks will fly into the air - it is you, along with drops, that threw many tiny crustaceans into the air. Here is probably the only - and wonderful - way to see, without a microscope, life - in every drop of sea water.

If something bright and big caught fire next to you in the water, it is the comb jelly - the largest luminous animal of the Black Sea. You can try to scoop it up with a boat of your palms - consider its radiance.

Not only planktonic microorganisms glow, but also many bottom ones: try to dive onto a rocky bottom and rub any smooth surface - it will glow; pick up a stone from the bottom, rub it - it will still glow when you emerge and lift it above the water. If there were no waves above the sandy bottom for a long time and people didn’t swim, even on the surface of loose soil a film of microlife is formed that can glow - then, walking along such a bottom, you will leave emerald traces.

We have already understood that plankters do not glow all the time, but when irritated - hitting an obstacle, strong movement of water. Such signals for a paddlefish or dinophyte algae are a sign of a possible approach of a predator, or even a collision with it. The flash should scare off the aggressor. How could such a small spark scare anyone? But compare the sizes! People are usually frightened by an unexpectedly lit ctenophore - and yet it is - just something - the size of an apple. For a small plank-eating fish - sprat, atherinka - a flash of green fire from the crustacean oytona can be a reason to flee. And an outbreak of dinophyte algae, in turn, can frighten off a copepod cancer or a worm larva. So the glow of plankton, which delights us so much on summer nights, is an active defense of weak plankters from voracious plankton feeders.

There are rare cases of a constant glow of planktonic algae - during a powerful flowering of noctiluca, or other dinophyte algae. The density of algae during such a powerful development of phytoplankton - millions of cells in a liter of water - is such that individual collisions, individual flashes of light, simply merge into a constant glow.

Some marine organisms have light signals that are not intended to scare away, but, on the contrary, to attract someone - to eat this someone, or, if it is an individual of the opposite sex, to mate with it.

Deep-sea anglerfish hang luminous organs in front of their open mouth, and the prey fish, swimming towards the light, ends up in the anglerfish's teeth. In the Black Sea, from the anglerfish family, one is occasionally found - the European anglerfish, or monkfish - a fish of a completely unusual type, but this species, although it has a fishing rod with a bait suspended over a wide mouth, does not glow. It rarely appears near our coast - sometimes it gets into trawl nets.

Monkfish - alas, does not glow.

The fact that there are no luminous anglerfish in the Black Sea is natural. For a successful hunt, they need complete darkness - these are the fish of the depths. In our sea, deeper than 150-200 meters, there is no oxygen necessary for breathing in the water, but there is poisonous hydrogen sulfide; fish can't live there.

Remarkable light appears in the sea in those places and at the time when some species of planktonic polychaete worms mate. Our Platinereis and Glycers, which we have just reviewed, unfortunately do not glow. But the usual Atlantic Nereis once a year arranges a fantastic light show in the waters of the Gulf Stream. On the night of the first summer new moon, the entire population of the island of Bermuda gathers on the walkways across the narrow straits that divide this island, located on the very rapids of the Gulf Stream. The only sea worm mating night of the year, a local Bermuda holiday - and I was lucky enough to be there at that time. Standing on a bridge over one of the island channels and peering into the black water, you finally notice the first, glowing with a bright, white-green light, a wriggling worm the length of a finger, the thickness of a match. It is not for nothing that the Gulf Stream was called a river in the ocean - the speed of the current is 4 km / h, we walk with that speed. And now the current brings new nereises, in half an hour - the water turns into a boiling, radiant, white-green stream - the worms swim, spewing luminous clouds of caviar and seed that mix before our eyes, these are fountains of light, this is - literally - a celebration of the birth of a new life accompanied by fireworks! You go down to the shore, catch a Nereis, and your palm is covered with a luminous liquid...

The glow of Nereis, in addition to attracting mating partners, also plays a deterrent role: in the sea there are many invertebrates and fish that can eat both worms and their eggs, but the bright light of the mass of Nereis, their eggs and seeds, will undoubtedly scare them away.

This story, of course, is not Black Sea, it is - just - about one of the wonders of marine life, most of which are waiting for you ahead. And the Black Sea is a very good sea for the first steps on this path.

Incidentally, the story of the Gulf Stream glowing from worms ended in general laughter from all the biologists who were then working at the Bermuda Biological Station. That evening, the whole company from the biological station went to look at the mating of Nereis. But one Japanese did not go - he said that he had already seen a similar phenomenon. We returned late at night, joyful, animated, found and pushed a sleepy Japanese biologist aside, began to tell him ... He stopped us, and silently led us along - it turned out that we were going to the toilet. Fresh water in Bermuda is very scarce, and to flush toilets, water is pumped into tanks directly from the sea. The Japanese put out the light in the toilet, pressed the drain... Streams of luminous, sparkling water poured into the toilet, illuminating the cramped room.

The Black Sea is a reservoir of contrasts, stories and legends. Like any huge water resource he has hundreds of secrets. Particularly interesting is the Black Sea at the junction with the Sea of ​​Azov - there you can appreciate the beauty of their differences and scale. If the Sea of ​​\u200b\u200bAzov is more like a huge lake with a shallow depth, then the Black Sea is a real abyss. An ominous, beautiful and breathtaking abyss.

Paleontologists believe that in the Black Sea region since the formation of the Earth there were salty reservoirs: the Pontic, and then the Meotic Sea. In other periods, the region dried up, and fresh springs-lakes formed here. The modern boundaries, depth and type of water, the sea acquired a little more than 8000 years ago. The reason for these changes was a devastating earthquake that formed the Bosphorus. Due to him, the Mediterranean Sea connected with a water source nearby and began to give water to the “newborn”.

The area of ​​the Black Sea is equal to more than 422 square kilometers. Its length is 580 km from north to south, while the maximum depth is 2210 m. The reservoir connects southern Europe and Asia Minor.

Facts, mysteries and wonders of the Black Sea

More than one long story or legend can be told about the Black Sea. Here are just 15 small but interesting facts about him:

1. According to an ancient legend, Jason set out on a journey along the Black Sea with the Argonauts in search of the Golden Fleece. Their path ran through land and water to Colchis.
2. The first references to the sea source are in the documents of the 5th century BC, they are associated with the expansion of the lands of the ancient civilization.

Black Sea, view from space

1. Only the Black Sea has many names that are used different nations and countries so far. Some names have disappeared over time. The ancient Greeks, for example, called it the Inhospitable Sea, or Pont Aksinsky. It was renamed Hospitable because the Greeks mastered the shores and found them attractive for winemaking, Agriculture, trade. In ancient Greek, the name began to sound Pont Euxinus. Much later, during Ancient Rus', the sea was called Scythian, somewhat less often - Russian. Other names are mentioned in historical documents found in European countries and in Asia. So, it corresponds to: Temarun, Holy Sea, Ocean, Akhshaena, Blue Sea, Cimmerian, Tauride. There is no exact information why it began to be called Black. Some historians believe that it is called so because of the color of the designation. Previously, the North was designated black, and this sea belonged to it. The second theory indicates that the sea got its name because of the large amount of hydrogen sulfide in the water. If any metal fell to the bottom, it turned black. However, thanks to the same hydrogen sulfide, sunken ships at the bottom remain several times longer than in the waters of other seas.
2. Only 2,500 species of animals live in the waters, perhaps this is due to the peculiarities of their composition. Usually 2-3 times more representatives live in the seas. In the Mediterranean - 9000.
3. Not less important in not in large numbers inhabitants has the same hydrogen sulfide. Its concentration at a depth of more than 200 meters is so great that not a single living creature is able to survive there.
4. In August, at night, the waters of the sea begin to glow due to the migration of plankton populations, which are phosphorescent.

Glowing plankton in the Black Sea

1. Unlike many seas and oceans, the name of the Black different countries has different inscriptions and pronunciations.
2. Due to its young age, the Black Sea may increase in size. The same goes for the mountains located around it. You can also notice this in the ancient cities of the Crimea, which go under water for tens of meters. Oceanologists believe that every 100 years the size of the reservoir increases by an average of 20 cm.
3. sea ​​dragon- the most predatory and deadly fish that lives in the Black Sea waters. Its thorns contain poison that can kill an adult.
4. The seal is a creature of a cold climate, but it finds refuge in the waters of the Black Sea.
5. The main biomass is represented jellyfish- only 10% is given to other creatures.
6. The Black Sea has one large peninsula - Crimea - and only 10 islands. If compared with the Caribbean or the Mediterranean, then this number is ten times less.
7. The Black Sea is a source of oil and gas. But they lie so deep that no country has yet reached the extraction.
8. Far from the coast, the sea surface is cut by huge whirlpools, the wavelength of which reaches 400 km.
9. In winter, the waters of the sea freeze only partially; there is an icy area near Odessa. Byzantine documents indicate that in 401 and 762 BC, the shackles of ice completely covered the sea surface.

The Black Sea has sheltered on its shores thousands of resorts and sanatoriums, which are visited by millions of tourists every year. However, few people think how much power and danger is hidden in these hospitable waters.

One of the Gipsledn lakes located in Australia attracts tourists with an incredible picture that can only be seen here - at night the water glows like a large neon lamp. Such a phenomenon as bioluminescence, in itself, is not uncommon and is usually caused by the activity of microorganisms called Noctiluca scintillans.

Colonies of these representatives of the simplest organisms accumulate in large numbers in warm waters, and then the water surface begins to glow.

However, the glow on Jeepsend Lake is unique, as it was the result of the accumulation of algae in the water. This species of them is one of the few that gives the water a neon glow. In many cases, science has not become aware of the functions of bioluminescence in the life of organisms. And for tourists it doesn’t matter at all, they just enjoy the beauties.

By the way, the lake gained popularity thanks to the avid traveler Phil Hart, who took a whole series of photos with this unusual phenomenon. In order to photograph the bioluminescence, Phil set the resolution of the camera to the maximum and threw stones and sand into the water.

sea ​​glow

The glow of the sea has long been one of the magical mysteries of the ocean. An explanation for this phenomenon has been sought for centuries. It was believed that the glow was caused by the phosphorus contained in the water or by electric charges that appear from the friction of water and salt molecules. It was even assumed that at night the ocean returns the energy of the Sun. And only in 1753, the naturalist Becker saw tiny unicellular organisms under a magnifying glass, no larger than 2 mm in size. They responded with light to any irritation.

The phenomenon itself was called "bioluminescence", which literally means "weak living glow". Bioluminescence is also called "cold" light, because it does not come from a heated source, but is caused by chemical reactions with oxygen. By the way, in nature there are still luminous bacteria and fungi. Thanks to bacteria, spoiled fish and meat products, as well as festering wounds, glow, which Paracelsus drew attention to. Well, at night, sometimes you can see the luminous threads of mycelium, which during the day will seem like ordinary rotten things to you.

The ancient Greeks did not consider it a sea, but called it the Meotian Lake.

The Sea of ​​Azov is a shallow flat reservoir with low coastal slopes. The water in it is muddy, and the banks are bare, low, clayey-sandy. In summer, the temperature of the upper layers of water often warms up to 28-30 degrees. At the same time, on its coast and above the surface all year round the winds are blowing. Sometimes they are so strong that they bring water to the shore. Then the sea level in the coastal zone rises by several meters.

According to one theory, the Sea of ​​Azov appeared 7,500 years ago as a result of a strong rise in the level of the Black Sea. And now the level of its waters is steadily falling. If the situation does not change, sooner or later this beautiful sea will disappear altogether.

Azov has many names. It is called the Sea of ​​Clams. The ancient Slavs called it the Surozsky or Blue Sea. And the modern name comes from the Arabic phrase Bahr-el-Azov or "dark blue sea". But, very often, its waters acquire a greenish-yellow hue due to the mixed sand. At the same time, a lot of plankton lives in the sea. In view of this, at night its surface glows at all. Here are some more interesting facts about this amazing reservoir of the planet:

1. This is the smallest sea in the world. Its maximum depth is only 13.5 meters. On average, the depths of Azov do not exceed 7 meters.
2. The ancient Greeks did not consider it a sea, but called it the Meotian Lake. The Romans were in solidarity with them, calling Azov the Meotian swamp.
3. The most distant sea from the ocean. Its waters are separated from the Atlantic by 4 seas: Black, Marmara, Aegean and Mediterranean. This is the most continental sea on the planet.
4. Its water is 3 times fresher than in other seas. It can quench your thirst. And all because of the abundant inflow of river waters into the Azov basin. In addition, water exchange with the Black Sea is difficult near the Sea of ​​Azov. Due to low salinity, it freezes in winter.
5. The most fishy sea in the world. Due to low salinity, the Sea of ​​Azov is rich in fish. There are even river views. Its small size turned the reservoir into a kind of fish nursery.
6. The main minerals are oil and combustible gas. The Sea of ​​\u200b\u200bAzov is rich in minerals hidden both at its bottom and under it. Gas fields frame its entire coast. The most promising oil and gas horizon are the deposits of the Lower Cretaceous. And the most oil-bearing - Maikop.
7. The Amazons lived on its banks. The state of Meotida was located on the coast of the Sea of ​​\u200b\u200bAzov. According to ancient Greek legends, beautiful female warriors or Amazons lived on the territory washed by the Black and Azov Seas. Almost all ancient writers write about them. The Amazons are first mentioned in the Iliad.