These intelligent marine mammals commit suicide solo and in pods. When in serious trouble, they shriek and can be heard at the distance of several kilometers. Mass self-destruction is a rare phenomenon among dolphins, so biologists are seriously alarmed and are trying to find out the causes.
Researchers have long been concerned about cetaceans beaching themselves. This phenomenon has been observed in all oceans and many seas. These days such suicidal acts have become more frequent, involving representatives of all 80 cetacean species. More often than not, this kind of suicide is committed by marine animals with schooling habits — e.g., 70 percent pilot whales, followed by black killer whales, sperm whales, and dolphins.
Some researchers believe that such suicidal acts are explained by the head of the pod going insane and being dutifully followed by the rest of the animals. Others insist on the “call of the wild” — when they somehow abide by their forefathers’ instinct, considering that dolphin’s forefathers once lived on land. Hence their inexplicable attraction to the terra firma — their genetic memory is at work. Still others assume that now and then dolphins find themselves in the so-called magnetic anomaly areas, which causes them to lose their bearings and they end up beaching themselves. The world free diving champion Jacques Mayol said the dolphins’ massive acts of suicide are their way to protest against man’s merciless attitude to the cetacean species, something like the Old Believers’ self-immolations. Regrettably, all these are assumptions, hypotheses. Let we try to figure out the situation.
SONAR GLITCH
This happened in March 2001, off the Greek shore in the Ionian Sea, when 12 dolphins flung themselves on the Peloponnese sand beach and died, not far from the village of Kiparissia. Two weeks later another eight dolphins followed suit, for no obvious reasons. Postmortem showed no signs of disease, poisoning, or physical damage.
As is often the case, the researchers had a stroke of luck. One evening, leafing through the files of periodicals at the local library, they came across a short item in which the local authorities warned the fishermen about sonar tests in the Kiparissiakos Bay, precisely where the dolphins had committed suicide. These marine animals find their bearings using their natural sonars, so any kind of disturbance or jamming makes them “blind.”
Shortly afterward, the researchers found out that NATO’s underwater research center had been testing a top secret low-frequency sonar capable of spotting the enemy’s new generation of soundless submarines. This kind of sonar worked at the 235-decibel level and higher, using a transmitter attached to the back of the test vessel. It emitted sounds so strong they could be received across the Atlantic. These sounds caused the dolphins’ mass death in the Ionian Sea. The animals were “blinded” by them, panicked, and flung themselves on the beach to die.
AIDING NEXT OF KIN
A number of researchers believe that one of the main reasons behind the death of these cetacean species is the instinct of preservation. When a member of a pod gets in trouble, it sends out a distress signal. If this signal comes from a deep place, a good distance from the shore, his “next of kin” zero in on him and help him out of the depth and to the surface, so he can breathe. As soon as the animal breaks the surface, its breathing reflex sets in. It is like first aid and artificial ventilation. However, this aid turns into a tragedy when the distress signal comes from a beached animal. The rest of the animals find it and fling themselves onto the beach, one after another, as though in a chain reaction, leaving dozens, hundreds, and even thousands of dead bodies.
DISEASE
What happens to a dolphin if man helps him out of the shallows and into the safety of deep sea? The result is a shocking surprise. In a matter of hours, or the next day, this dolphin will fling himself on the beach. Repeated rescue attempts invariably result in their ending their life like that.
Dr. Averin Tomilin, a reputed expert in biology, took the temperature of an ailing common dolphin in the Black Sea. He was standing half way to his waist in the water, holding the dolphin with his hands. The animal offered no resistance as long as his head was turned toward the shore. Once turned in a different direction, the dolphin struggled to get free and fling himself on the beach.
What makes these marine mammals beach themselves? Researchers believe the reason is the subconscious desire of contact with dry land on the part of ailing animals. The forefathers of this cetacean species, when mastering the sea, would return to dry land when in danger. It is possible that this instinct is still at work in the ailing marine mammals.
Dolphins are susceptible to countless nervous, stomach, skin, and other diseases. The big question is, What causes these ailments?
People have been discharging a mind-boggling amount of poisonous agents into the World Ocean, with an increasing number of dolphins falling prey to raw oil pollution.
At present, the levels of poisonous substances in the Sevastopol bays and in the vicinity of Feodosiya in the Crimea are higher than the norm: 5 times higher for mercury, 50 times for arsenic, and 500 times for pesticides. During their comparatively long life span these marine mammals inadvertently accumulate a great deal of harmful chemical compounds within their systems. This triggers various kinds of diseases. The skin of the dolphin that recently flung themselves on the Crimean beach showed sores and their inner organs were damaged. Nor are the researchers enthused by the bettering of seawater quality.
Says Mykola Shadrin, senior research fellow with the Institute of South Seas Biology at the National Academy of Sciences of Ukraine: “At present, only 14 percent of urban sewage is purified. Sevastopol is one of few big cities by the Black Sea that have practically no water purification facilities.”
Forecasts made by his colleagues are disheartening: “Countless indicators, such as the impoverished marine flora and fauna, chemical content, and pollution point to the fact that the Black Sea is about to die. Before long it will turn into a huge stinking lifeless and colorless puddle.”
Apparently the dolphins, as indicators of seawater purity, were the first to sense the coming disaster. These intelligent and good-natured animals took their lives to warn us against an impending ecological catastrophe.
