A dead whale on the shore is a sad sight, forcing us 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 do whales wash ashore?
The mass beaching of whales is one of the tragic and intriguing mysteries of nature, over which many scientists are puzzling over to this day. 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 ocean expanses end their lives on a sandy shore and die under the scorching sun? Why did the whales come ashore?
For example, in February 2015, about 200 dolphins washed up on the coast of New Zealand. According to scientists, such a mass phenomenon has not been observed for more than 10 years. Despite the best efforts of the rescuers, only a hundred individuals managed to survive.
The rest died under their own weight and due to lack of water. While whales are most commonly seen in large numbers, most of them are among deep-sea species.
Ocean sound pollution
The endless expanse 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 noises (from submarine engines, mining, military testing and fishing). As a result, under the influence of sonar, dolphins and whales lose their hearing by almost 40%.
What does the loss of hearing (a thin instrument capable of detecting the slightest vibrations in water) mean for an animal whose life depends on the ability to hear? Underwater sound traps disorientate animals in the water, knocking them off their usual path, so whales and dolphins, lost in space, swim up in shallow water.
Too fast ascent to the surface contributes to the occurrence of bending sickness inherent in divers, in which, due to a sharp decrease 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 during the autopsy of dead animals. The nitrogen bubbles contained in the blood of whales, according to scientists, can be directly affected by loud sounds from submarine engines and explosions. Under the action of sound waves, the bubbles, rapidly expanding and contracting, canclog blood vessels, damage tissues, injure the nervous system.
Whale mass deaths caused by military exercises?
Strong explosions, in addition to clogging blood vessels, can cause rupture of animal organs. This phenomenon (lung ruptures and bleeding of internal organs) was observed by scientists when examining whales and dolphins that washed ashore during or after military exercises. For example, in 1989, during a naval exercise near the Canary Islands, 24 whales washed ashore. Why did the whales come ashore? Most likely, the unbearable underwater noise, which literally deafened the aquatic inhabitants, became the reason. The harm caused by submarines to marine life is most carefully studied by the Americans, since it is in this country that the military complex is subjected to the most severe public pressure.
Whales washed ashore even before the manifestation of man-made evolution of mankind and the appearance of submarines. What in those days could cause this feature of the inhabitants of the oceans? In 1950, 64 whales washed up on the coast of Stronsay Island, 5 years later 66 dolphins died here. What makes animals choose this way of dying? Why did the whales come ashore?
Magnetic fields fail?
According to Margaret Klinowski's theory, whales migrate annually to warm waters to mate and give birth, after which the marine animals return. The travel paths largely depend on magnetic fields, which are a kind of landmarks. In places of greatestfluctuations in these fields, whales can lose their bearings and swim in shallow water. It has been observed that mass suicides of whales mainly occur immediately after solar flares that distort magnetic lines.
According to one version, whales are washed ashore due to changing climatic conditions. Ocean currents bring cold water from Antarctica, forcing whales to swim in shallow water to keep warm. In Australia, the release of more than 80 whales was recorded, literally dotting with their bodies a five-kilometer coastal zone. Only 25 were rescued.
Why did the whales come ashore? What caused the mass suicide? Maybe a loss of orientation, which weather conditions can disrupt? In stormy weather, with gusty strong winds, a storm tide or the so-called surge of water can occur. An animal that swims too close to land may stay there, not orienting itself in time when the water subsides.
Self-regulation of numbers is another suggestion of a massive stranding of whales. The version exists, although the number of whales in nature is not so large that it was required to reduce it.
The cause of the death of whales - pollution of the oceans?
As a reason for the massive beaching of whales, one can consider the pollution of the World Ocean, which is gradually turning into a dump of catastrophic proportions. A special accumulation of garbage, a fifth of which is industrial emissions and oil waste, falls on the shores of the Hawaiianislands. In size, this garbage patch, located in the Pacific Ocean, is commensurate with the continental United States. Naturally, such a huge landfill, the mass of which exceeds 100 million tons, negatively affects cetaceans. Although these animals are not fish and, unlike them, breathe air rather than dissolved oxygen in a polluted aquatic environment, they can be harmed by such dumps by injury and getting into oil slicks.
Perhaps a socio-psychological factor?
The psychic hypothesis is also put forward as one of the reasons for the mass beaching of whales. Whales and dolphins are social animals subject to the influence of the leader. If the latter loses orientation in space and leads the flock to shallow water, then the animals, despite the mortal danger, still continue to follow him.
There is an infectious theory of suicide of cetaceans, which is now paying special attention to scientists around the world. Some viruses that infect mammals adversely affect the hearing apparatus of animals, causing diseases such as meningitis and encephalitis, provoking the failure of the echolocation system. Having lost orientation in space, the whale (photo can be seen in the article) begins to suffocate, so it is thrown ashore in order to ease its breathing.
Returning to your native element will only aggravate the current situation. Previously, it was believed that cetaceans do not succumb to damaging viruses. In fact, harbor seals, the food of killer whales, may be their carriers.
After accidentally hitting the shore, an 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.
