4 meters in length: where the beluga disappeared - the largest river fish on the planet

Just some 100 years ago, fabulous fishes were caught in the Volga by modern standards: weighing up to 1.2-1.5 tons and a length of more than 4 meters. And these are not fishermen stories at all, but confirmed scientific facts. These were huge beluga, which had not been seen in the Volga for a long time, and the few representatives of this species that have remained in our days do not much resemble their great ancestors. But what happened to the largest freshwater fish on the planet? Why was it almost gone, and the few individuals that remained do not at all resemble the most huge freshwater fish on the planet with their modest sizes?

Beluga belong to the sturgeon family and live in the basin of the Caspian, Black and Azov Seas. This fish belongs to migratory species that live in the seas, but enter the rivers for breeding. The population of the Caspian beluga spawns in the Volga, Urals, Kura, Terek, the Azov beluga spawns in the Don River. The Black Sea beluga lives on the shores of Ukraine, Bulgaria and Romania, therefore spawning in the Danube, Dnieper and Dniester. Back in the middle of the last century, the beluga population lived off the coast of Italy in the Adriatic Sea, but today this species of sturgeon is not found there.

Belugas are predatory fish that feed on small aquatic organisms, mollusks, larvae and crustaceans at a young age, and when they reach a venerable age and size, they switch to larger prey - river fish. Belugs are real centenarians, as they can survive up to 100 years. But this is not the only record of these fish. The fact is that belugas grow all their lives, that is, by the size of the fish you can roughly determine its age. Well, the famous 4-meter specimen of the beluga, which was caught at the beginning of the last century in the Volga, most likely was close to its centennial anniversary.

But 4-meter giants are records of bygone days, nowadays there are no such beluga. Those belugas that swim today in the waters of the Caspian Sea and the Black Sea are extremely small, despite the fact that the species is listed in all the Red Books that are possible. Several factors led to such a deplorable situation, but the main culprit of such a plight of the Belugas, of course, is man.

Intensive fishing and pollution of river and sea waters led to a catastrophic decline in the population in the 20th century. The situation was worsened by the construction of numerous hydroelectric power stations on the largest rivers of Europe, which were not equipped with fish passage mechanisms, which did not allow the fish to climb upstream to their spawning places. The Volga, Kama, Kura, Don, Dnieper and Dniester were all blocked by hydroelectric dams, which deprived Beluga of the majority of spawning sites.

Another important feature that influenced the sharp decline in the population is a very long period of growth of belugas. In order for the beluga to reach reproductive age, a lot of time must pass. The males of the Caspian beluga are capable of breeding no earlier than 13-18 years, and for females this figure reaches 16-25 years. Thus, in order for the beluga to grow and be able to leave offspring, a lot of time must pass.

The fact that the Beluga needs to be saved, especially the population of the Sea of Azov, which is in a more deplorable state compared to the Caspian Beluga, became clear in the middle of the 20th century. Beluga began to breed in special nurseries, to release eggs and juveniles into the Sea of Azov. This allowed a little stabilization of the situation, but the volumes released were not enough to maintain and increase the population.

The current state of the species is of serious concern to ichthyologists. The weight of most belugas caught in the last 20-30 years does not exceed 300 kilograms, and the age of these fish is not more than 40-50 years. If in the middle of the XX century about 25 thousand belugas were recorded in the Volga, spawning, at the beginning of the XXI century their number did not exceed 5 thousand. It is hoped that ecologists and fish breeding specialists will be able to preserve this amazing species of fish and beluga of incredible size will again be found in the Volga.