Mass throwing of whales onto land. Why did the whales go ashore? Why are whales washed ashore? Why are whales washed ashore

People have long watched the tragic death of whales and dolphins on the shore. Even Aristotle, who was the first to describe the habits and characteristics of cetaceans more than 2,300 years ago, mentioned the sad tendency of whales to run aground suicidal. In his Historia Animalium, Aristotle wrote: “It is not known why they are thrown onto dry land. In any case, it is known that they do it at times, and for no particular apparent reason. " Once on the shore, the whale slowly and painfully dies under the weight of its own body. Why are whales washed ashore? This happens too often to be considered an accident. There are several hypotheses in this regard.

Fig. 1 Humpback whale

1. Weakness or injury.

A whale, being sick or wounded, loses its ability to fight the current and ends up on the shore. This explanation looks logical and prosaic. Often dead and dying marine animals are found on the coast, with damage received at sea from ships, fishing nets and from predators. The natural old age of whales can be attributed to the same hypothesis. Interestingly, whales as such do not grow decrepit. But with age, their senses weaken, and they break on underwater rocks, find themselves aground, or become prey for sharks and killer whales. Whales retain their reproductive ability throughout their lives. The bowhead whale is the longest-living warm-blooded animal. Their age, judging by the harpoons removed from the bodies, can reach 200 years.

2. Periodic changes in the environment.

Scientists at the University of Tasmania studying whales analyzed data collected over 82 years of monitoring off the coast of Tasmania and Australia, and noted that cases when whales are washed ashore are more frequent every 11-13 years, and this coincides with change of the wind rose. Perhaps the changed wind is driving plankton and small fish to the shore, luring whales too close to the shore. It is also possible that the changed wind changes the wave in the ocean, which in turn disorients the whales, and they get too close to the shore. Once in shallow water, whales quickly get tired and die. Ocean tides are also dangerous for whales and dolphins. Only the California gray whale can easily tolerate drying out at low tide.

Fig. 2 Rescuers help a dolphin in the low tide zone to wait for high tide.

3.Sociality of whales

Strong social bonds within a herd may be the reason why whales are washed ashore in large numbers. If one whale gets into shallow water and cannot get out, it begins to emit a distress signal, relatives seek to help it and also run aground. Illness and weakening of the whale - the leader can destroy the entire herd. According to one theory, whales still have a deep instinct inherited from their land ancestors: they are afraid of drowning. The weakened whale swims upward, closer to the air, and the rest of the herd follow him. Whales are characterized by mutual assistance, it is a known fact that dolphins save drowning people. But it is this quality that destroys them.

Fig. 3 One of the most massive known deaths of grinds. 400 of them landed on the coast of New Zealand, some were rescued, but the next day another 200 grinds followed suit.

4 . Impact of people.

Although submarines and sonars are relatively recent, it is difficult to ignore their impact on the environment, in particular whales. On the shores of Great Britain over 20 years, the number of cetaceans escaped has increased by 25%. Environmentalists and scientists attribute this to the use of powerful military sonars. Whales have fine hearing, and the loud sound of sonars scares them, makes them rapidly rise to the surface or go to depths, and disorients them. But this is not the worst thing, too fast ascent from a great depth to the surface can threaten decompression sickness, known to divers. With it, gas bubbles form in the blood from a rapid change in pressure. Examination of the bodies of whales confirms the presence of gas bubbles in the blood.

In the middle of the twentieth century, US Navy ships were actively conducting exercises in the Caribbean and Mediterranean seas. It was found that cetaceans did run aground more often when the ships of the navy were practicing operations there using sonars. Now exercises in the habitats of beak beaks are prohibited. In 2000, 17 cetaceans of 4 different species were stranded on the shores of the Bahamas following sonar drills in the area.

5 . Geomagnetic navigation error.

Many migratory animals use geomagnetic navigation, including whales. The humpback whale is capable of covering a distance of 2000 km without stopping, without straying more than 1 degree off course. In total, humpbacks travel about 6500 km during their migration. Yet, for reasons not fully understood, animal navigation sometimes malfunctions. It is most likely that some electromagnetic forces interfere with the proper operation of the whale's navigation system, for example, magnetic storms on the Sun are known to sometimes knock flocks of migratory birds astray. So in 2015, a flock of pink flamingos for some reason flew to Siberia. In addition, artificial sources of magnetic waves, such as radar and possibly even television and radio signals, can significantly affect the biocompass of marine animals. Perhaps this explains the fact that rescued whales are often washed up again in the same place almost immediately after being rescued.

These are the most scientifically supported reasons why whales are washed ashore. Fortunately, people no longer regard the defenseless sea giants on the coast as easy prey, as in past centuries, but, on the contrary, try to return the whales to the sea as soon as possible. And there is hope that in the future, when scientists find the answer to the question of why whales are washed ashore, people will be able to predict or even prevent further cases of mass death of whales.


Fig. 4 Surfer and a whale's tail.


A dead whale on the shore is a sad sight, forcing one to try to understand the cause of death of such a massive and beautiful animal. And if it's not one whale, but two, five, dozens?

Why are whales washed ashore?

The massive release of whales ashore is one of the tragic and intriguing mysteries of nature, over which many scientists are still racking their brains. The sad sight of the dead bodies of huge animals in an unusual environment for them causes a feeling of bewilderment and pity. What makes the main inhabitants of the oceanic expanses end their lives on the sandy shore and perish under the scorching rays of the sun? Why did the whales go ashore?

For example, in February 2015, about 200 dolphins stranded on the coast of New Zealand. According to scientists, such a massive phenomenon has not been observed for more than 10 years. Despite the maximum efforts of the rescuers, only a hundred individuals managed to survive.


The rest died under the weight of their own weight and due to lack of water. Although most often group emissions are observed in whales, most of them are among deep-sea species.

Sound pollution of the ocean

The endless body of water is filled with many sounds, most of which are of natural origin. Increasingly, the measured life of the ocean is disturbed by human-made noise (from submarine engines, mining, military trials and fishing). As a result, dolphins and whales lose hearing by almost 40% under the influence of sonar.

What does hearing loss (a delicate instrument capable of distinguishing the slightest vibrations of water) mean for an animal whose life depends on hearing? Underwater sound traps disorient animals in the water space, knocking them off their usual path, so whales and dolphins, getting lost in space, swim into shallow water.

Ascending too quickly to the surface contributes to the emergence of decompression sickness inherent in divers, in which, due to a sharp drop in pressure, nitrogen bubbles accumulate in the blood and damage internal organs and blood vessels. This assumption is confirmed by scientists who found signs of such a disease when autopsying dead animals. The nitrogen bubbles in the blood of whales, according to scientists, can be directly influenced by loud sounds from submarine engines and explosions. Under the influence of sound waves, bubbles, rapidly expanding and contracting, can clog blood vessels, damage tissues, and injure the nervous system.

Are the whales killed in military exercises?

Strong explosions, in addition to blocking blood vessels, can rupture animal organs. Scientists observed this phenomenon (rupture of lungs and bleeding of internal organs) when examining whales and dolphins that were thrown ashore during or after military exercises. For example, in 1989, during a naval exercise near the Canary Islands, 24 whales stranded ashore. Why did the whales go ashore? Most likely, the reason was the unbearable underwater noise, which literally deafened the aquatic inhabitants. The harm to submarines caused to marine life is most thoroughly studied by the Americans, since it is in this country that the military complex is subjected to the most intense public pressure.

Whales were thrown ashore even before the manifestation of the man-made evolution of mankind and the appearance of submarines. What in those days could determine this feature of the inhabitants of the oceans? In 1950, 64 whales were thrown onto the coast of Stronsay Island, after 5 years 66 dolphins died here. What makes animals choose this method of death? Why did the whales go ashore?

Failure of magnetic fields?

According to Margaret Klinowski's theory, whales migrate to warm waters every year for mating and calving, after which the marine animals return. The routes to be followed largely depend on magnetic fields, which are a kind of landmarks. In places where these fields fluctuate most, whales can lose orientation and swim in shallow water. It has been observed that mass suicides of whales predominantly occur immediately after solar flares that distort magnetic lines.

According to one of the versions, whales are thrown ashore due to changes in climatic conditions. Ocean currents bring cold water from Antarctica, forcing the whales to swim in shallow water in order to keep warm. In Australia, the release of more than 80 whales was recorded, literally streaking with their bodies a five-kilometer coastal zone. Only 25 individuals were saved.

Why did the whales go ashore? What caused the mass suicide? Maybe a loss of orientation, which can be disturbed by weather conditions? In stormy weather, gusty strong winds can cause a storm surge, or so-called surges. An animal, having swum too close to land, may stay there, not having its bearings in time when the water subsides.

Self-regulation of abundance is another assumption of a massive release of whales ashore. The version still exists, although the number of whales in nature is not so large that it needs to be reduced.

Cause of death of whales - pollution of the oceans?

Pollution of the World Ocean, which is gradually turning into a dump of catastrophic proportions, can be considered as the reason for the massive release of whales ashore. A special accumulation of garbage, one fifth of which is industrial emissions and oil waste, occurs on the shores of the Hawaiian Islands. Located in the Pacific Ocean, this garbage patch is about the size of the continental United States. Naturally, such a huge landfill, the mass of which exceeds 100 million tons, negatively affects the cetaceans. Although these animals are not fish and, unlike them, breathe air rather than dissolved oxygen in polluted aquatic environments, injuries and oil spills can cause harm from such landfills.

Perhaps a socio-psychological factor?

The psychic hypothesis is also put forward as one of the reasons for the massive release of whales ashore. Whales and dolphins are social animals, influenced by the leader. If the latter loses orientation in space and leads the flock into shallow water, then the animals, despite the mortal danger, still continue to follow him.

There is an infectious theory of cetacean suicide, which is now receiving special attention from scientists around the world. Some viruses that infect mammals negatively affect the hearing system of animals, causing diseases such as meningitis and encephalitis, causing echolocation system failure. Having lost its orientation in space, the whale (the photo can be seen in the article) begins to suffocate, therefore it is thrown ashore in order to ease its breathing.

Returning to the native element will only aggravate the current situation. It used to be thought that cetaceans did not succumb to infecting viruses. In fact, sea seals, the food of killer whales, can be their carriers.

Having accidentally hit the shore, the animal can give distress signals to its fellows, who immediately rush to the rescue of the poor fellow and fall into the same trap, also calling for help.

In February 2017, the world was rocked by tragic news: more than 400 whales were sighted off the coast of New Zealand. The New Zealand Department of the Environment noted that this suicidal incident among cetaceans was the most massive in the history of the state. By the time the mammals received help in the form of department employees, volunteers and local residents, about 70% of the "suicides" were dead. Nevertheless, all were acceptedmeasures to save the surviving whales: they were sent to the open sea at high tide.

« Why the whales washed ashorein that day? " - this is the question scientists and biologists have asked.

Mass suicides in nature

Historical evidence suggests that whales are far from the only animals with suicidal tendencies. So, July 2005 was remembered by biologists for the case of mass suicide of sheep. The animals gathered in a herd of up to 1.5 thousand and rushed into the abyss.

In the early 1980s, hundreds of sharks were found who committed suicide on the west coast of the United States. The staggering figure of 10,000 sea lions is the number of suicidal animals found on the coast of the Caspian Sea. However, why do blue whales be washed ashore?more often than other representatives of the fauna?Let's try to understand the main theories put forward by scientists.

MThe massive death of animals is a global environmental disaster. Biologists and ecologists unanimously assert that actions performed by mammals can serve as an alarm bell, which should make humanity stop and look around, look at their smaller brothers. One of the most common versions of why dolphins and whales are thrown ashore is based on the problem of environmental pollution.

Version # 1. Sound pollution of the aquatic environment

The ocean is rich in sounds of both natural and unnatural origin. The latter include human-generated noises. Can the blame for the mass suicides of whales be shifted onto the shoulders of children splashing in the sea water and adults vacationing along the coast? No reallya huge percentage of the world's oceans' noise is the result of scientific and technological progress. For example, the roar of submarine engines, noises associated with fishing, mining and development of minerals, as well as underwater military tests carried out by humans - all these activities lead to sound pollution of water bodies, violating the noise level permissible for ocean inhabitants.

Sonars have the greatest negative impact on the health of whales and dolphins. The use of military equipment is capable of stunning cetaceans for at least forty minutes. But regular presence in the noisy ocean can lead to significant disturbances in the functioning of the hearing organs in animals inhabiting the depths of the sea.

Even though some of the cetaceans are able to detect dangerous radars, "smelling" them thanks to the internal multifunctional radars,some individuals are still threatened with a sonic underwater trap, which limits the orienting abilities of mammals in space. What happens to an animal when it is trapped, we formohmas a result of underwater relief and currents?Layering on top of each other, streams of cold and warm water reflect the sound entering them. Being in such a trap, sea inhabitants cannot get out of it, since they completely lose their orientation. Here,: losing their way, they easily swim out into shallow water.

Some scientists suspect that parts of mammals have to swim to the surface of the water, thereby exposing themselves to decompression sickness, which is characterized by the accumulation of nitrogen bubbles in the blood, when the body is re-immersed in the water. The latter are dangerous in that they can damage the internal system of organs and blood vessels. The number of bubbles can quadruple: as a result, blockage of blood vessels and tissue damage, injury to the nervous system, and total disorientation. Military exercises with their characteristic underwater explosions and the roar of submarine engines are already a factor affecting the percentage of nitrogen bubbles in the blood. Signs suggestive of the development of decompression sickness among the whales that have washed ashore were found during autopsy. Also, "suicides" are characterized by ruptures of the pulmonary system, internal bleeding, and organ damage.

Version number 2. Earth's magnetic field

Ecologist Margaret Klinowski has put forward the theory that the cause of mass suicide among whales is the effect of magnetic fields on the health of mammals. Every year, whales go on long voyages, where in warm waters they could mate and give birth to cubs. With the end of the "mating season" comes the period of returning home.The main guideline for determining the migration route Earth's magnetic fields serve as cetaceans. However, there are areas of the planet where, due to the activity of the Sun, the effect of magnetic fields is weakly expressed - this leads to the fact that the whales lose the ability to move in the desired direction and swim to the coastal territory.

A serious blow to the sonar organ of cetaceans is caused by flares observed on the Sun, which are known to provoke distortion of magnetic lines. As a result, whale routes are disrupted.

Version number 3. Population regulation

One theory is that mass whale suicide is a way of numerical self-regulation. Nevertheless, scientists consider this reason why the whales washed ashore as untenable. Not only is it difficult to call the world's whale population catastrophically higher than the norm - this number is decreasing every year. The latter factor suggests that overpopulation is not an explanation for why whales are washed ashore.

Version number 4. Trash is to blame!

Environmentalists are sounding the alarm! In the Pacific Ocean, near the Hawaiian Islands, two huge spots of debris were found.The modern ocean, which some boldly call plastic soup, is in dire straits. One-fifth of all marine debris, the size of which is equal to the size of the continental size of the United States, is waste from the oil industry.According to ecologists, the total weight of waste in the water reaches 100 million tons.

Now back to the animals. Do you think it is easy for them to live in such a dump? In addition to disrupting the oxygen balance of water, debris can injure representatives of the marine animal world. It is not uncommon for whales to find themselves in oil spills. All these factors, one way or another, force cetaceans to seek “cleaner and better” life. Maybe,becausewhatbelieve thaton the landcanfind temporary shelter.

Version number 5. Sociology of cetaceans

Whales and dolphins are social animals. They are characterized by the formation of flocks with the choice of a leader, followed by the entire group of mammals. So, in case of disorientation of the head of the flock in shallow water, all his "followers" can swim out.

Version number 6. Infection

Australian scientists say: an infectious disease that causes disturbances in the functioning of the hearing aid is the reasonwhy dolphins and whales are washed ashore... They believe that a particular virus spreads meningitis, encephalitis and echolocation systems among marine mammals. As a result, there is a limitation in motor abilities. In search of air, whales swim to the shore, where they hope to ease their breathing. Sea seals are considered to be the main carrier of the disease.

Version number 7. Romantic legend

Why whales are washed ashore, scientists and ecologists have been trying to figure out for a long time. The only thing that scientists are sure of is that cetaceans can be safely called the most complex marine animals, the behavior and lifestyle of which is extremely difficult to predict. Therefore, while biologists are racking their brains over the mystery of mass suicide of whales, ordinary people, far from science, are developing their own theories aboutwhy the whales washed ashore.For example, some believe that old whales swim ashore to rest. Others find whales as romantic animals prone to mental distress that lead them to commit suicide.

In fact, all the dramatic theories surrounding whale suicide cannot be denied. So, scientists have confirmed that often the scenario according to which mass suicidal incidents develop are cases when one of the whales, once on the shore, begins to send distress signals to relatives. His whale relatives rush to the rescue, thereby sacrificing their lives.

Conclusion

Reasons,why the whales washed ashore, a bunch of. Moreover, none of them is universal.

Scientists hope to find the true factor provoking mass suicide in cetaceans, andprevent the eerie spectacles associated with the slow death of whales on land under the rays of the scorching sun or from their own weight.

 

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