Posted 2 апреля 2021,, 10:27
Published 2 апреля 2021,, 10:27
Modified 25 декабря 2022,, 20:57
Updated 25 декабря 2022,, 20:57
Yuri Korobov, expert in the field of ecology and development of coastal territories of the Volga, Chairman of the Board of Directors of the Berega Company
For representatives of the aquatic world, spawning is a period of reproduction, when, when favorable conditions arise for each species, female fish lay eggs (eggs) in the water, from which later, after fertilization with the milt of a male, offspring will appear. For a person, often, the meaning and concept of spawning changes due to the perception of caviar only as a desired delicacy, delicacy. And people in this regard are more terrible than predators.
The depletion of natural resources has to be constantly reminded. Many people talk about a decrease in the number of fish in the Volga. It must be admitted that such a problem exists, and it is often due to human activities. People build dams, use the water of rivers for technical purposes (sometimes as a natural transport of wastewater), are engaged in navigation (as a result of which oil products get into the water, and in the event of flooding of floating craft - and more dangerous chemicals), they use the "gifts of the reservoir" for food (sometimes barbarously selectively, focusing, for example, on caviar).
Over the past two centuries, starting in 1843, when, as a result of the construction of the Upper Volga beishlot (a dam with blocked holes for water discharge) near the village of Selishche, the Upper Volga reservoir appeared, located in the territory of the modern Tver region, in the Penovsky, Ostashkovsky and Selizharovsky districts, the Volga has changed a lot. Now only in its upper reaches, in addition to the Upper Volga, there are the Ivankovskoe, Uglichskoe and Rybinskoe reservoirs.
The danger of man-made changes in water bodies for river fauna lies not only in changing ecosystems, establishing barriers on migration routes and dividing habitats - in addition to everything, a person gets the opportunity to artificially regulate water resources, in particular, changes in the level of high water.
There is such a concept as low water - an annually repeating seasonal phase, characterized by low water content and long standing low water level in the river. The word comes from the ancient Russian "mezhenina" - "drought", "lack". On most rivers in Russia, there are two periods of reduced runoff - summer and winter low-water periods. During such periods, thanks to natural instincts, fish do not go to spawn, waiting for floods - the time when the offspring will definitely not be left without water.
But a person, guided by his own interests (often in order to avoid spring flooding), sometimes changes natural cycles. So, floods can happen in winter if a hydroelectric power plant (HPP) decides to discharge water. Since a cascade of hydroelectric power plants has been created on the Volga, the discharge often goes "along the chain". The greatest danger in this case is in limiting the flow of water (controlled low-water period) during natural periods of floods. In some case, the fish may simply not spawn, but then it will have the so-called resorption - the process by which the eggs are gradually processed inside the body - while it may not produce offspring the next year. In the worst case, an insufficient water level can dry out the deposited eggs. The media wrote, for example, about the case when the water in the Kuibyshev reservoir during the spawning period was almost 3 meters below normal. Considering that fish often go to spawn in shallow water, to a depth of 0.5 to 1.5 meters, such a decrease in the level will entail consequences that cannot be compared with the damage from pollution or poaching.
Egg to egg
Pollution of the Volga is a global problem. Here we would like to draw your attention to an unexpected reason for the removal of fish from the Volga, associated with the increased demand for freshwater fish caviar, in particular pike, which, after a little processing, can turn black. They sell it, after blackening, as an alternative to sturgeon, and sometimes pass it off as such (in particular, stellate sturgeon caviar, close in size). As a result of a simple marketing move, the pike was simply on the verge of extermination, especially in places where sturgeon were caught and illegal caviar in the lower reaches of the Volga (poachers, in caviar excitement, do not hesitate to deceive).
The increased price of salmon caviar provoked there is a demand for black pike caviar on the legal market, because sturgeon caviar has become almost inaccessible due to its high cost (about 3,500 rubles per 100 grams). But not only the pike has become a victim of changed gastronomic preferences - offers of pike perch caviar appeared on the Internet, dried caviar of roach , roach with caviar, or catfish caviar.
The growing popularity of freshwater fish caviar frightens the fact that it provokes interest in such a product among poachers who, in pursuit of a delicacy, can simply throw the fish away. It is known when they did this with sturgeon, let alone other, less valuable families.
Of course, you can't forbid people to eat caviar. But, firstly, in the process of processing and storage, it can lose a large number of its unique properties. Secondly, often, when processing caviar, it is abundantly salted - from such a product, there may be more harm than good. Thirdly, in bream, for example, with an average fecundity of about 100,000 eggs, up to 45 individuals live up to sexual maturity, and while the fish matures for spawning, only two or three females may remain, the rest will be caught by fishermen. Of the 600,000 eggs laid by a female carp, 93% die in the first 10 days, and only about 3% survive to the age of three.
The problem of the consumption of caviar as a gastronomic delicacy in other countries is not acute, the head of the information agency for fisheries Alexander Saveliev told the radio station "Moscow speaking". Interestingly, in America, caviar is practically not eaten. People are puzzled by the very fact that you can eat "fish eggs". Caviar lovers are sometimes looked upon as eaters of other exotic things, for example, frogs or earthworms. And if black caviar can appear on the table as a "Russian" appetizer, then red caviar, which is obtained in large quantities in North America, is used in the production of dog food or imported to Russia and Japan. Some explain this by the fact that during the existence of slavery in America, the internal organs of animals, birds and fish were intended for cooking food for slaves.
Roughly the same attitude towards caviar among the inhabitants of Europe. Perhaps because there are no endless Russian expanses in Europe. Consequently, there is no possibility of poaching on an industrial scale. Perhaps the Europeans' dislike for the delicacy popular in Russia was the result of a long-standing ban. In England at the end of the 12th century, the death penalty was imposed by hanging for poaching. As a special favor (for the elderly and young people), the death penalty was replaced by the chopping off of a hand or fingers (as a rule, the index and middle, so that henceforth it was impossible to pull the string), or the deprivation of the eye. At the beginning of the 13th century, the death penalty for poaching was replaced by a fine, imprisonment for a year or expulsion from the country. Which also disciplined.
In 2019, more than 21 thousand tons of red salmon caviar were produced in Russia, the black caviar market can be up to 1,000 tons of a delicacy. The volume of consumption of caviar from fish of other species is practically not recorded. Of course, this is also thousands of tons. A huge amount of fish eaten in the form of caviar could replenish our dwindling reservoirs. Since the 2010s, the pike perch catch in the Volga, for example, fell from 55.6 to 39 tons, and in the early 1980s it was caught up to 250 tons. A decrease in the population of sturgeon (which existed in the days of the dinosaurs, and only now were under the threat of extermination) has led to the fact that in Russia since 2007 the sale of sturgeon caviar obtained from fish grown in natural conditions is illegal, and since 2009 it has been sturgeons are not allowed even for scientific purposes. Since 2015, the Criminal Code and the Administrative Offenses Code have provided for punishment for violation of the moratorium not only for poachers, but also for buyers of poaching products as accomplices.
Summing up, let's say that among the reasons for the decline in the Volga fish population are the regulation of the flow and water level by dams, untreated industrial and agricultural wastewater and poaching, sometimes spurred by the fashion for affordable caviar.