In the midst of the long-awaited and all-time favorite holiday season. One part of the country’s population goes to warm countries, and the other part – to our main resort zone – to the Black Sea. About how dangerous for tourists overseas trips to hot countries, we have already heard plenty. The eerie information from the All Inclusive area about the absolute insecurity of Russian holidaymakers probably repelled many of the desire to go to the hill. For example, I do not want to go to Egypt at all! However, for holidaymakers on their native, favorite and seemingly safe Black Sea resorts, it may also be useful to learn about some not very pleasant things …
The conversation will not be about small and large thieves – this is written and said enough, but about one ecological feature of the Black Sea. As early as 1890, the Russian oceanographic expedition proved that in the depths of the Black Sea there is a lot of dissolved hydrogen sulphide – it is a poisonous gas with a sharp smell of rotten eggs. Already in the XX century it turned out that hydrogen sulphide is not just a lot, but very much – it is present throughout the deep water area of the sea, approaching the surface about 100 meters in the center and 300 meters off the coast.
Generally, hydrogen sulphide in sea water is not a unique property of the Black Sea. Quite large areas contaminated with this gas are in the Indian and Atlantic oceans, sometimes appear in the Caspian and other seas. However, in none of the reservoirs the hydrogen sulfide stratum never closely approximated the mark of the Black Sea – 90% of the total volume.
In the 1990s, the topic of hydrogen sulfide in the Black Sea was quite popular. This happened after the publication of the article “Will the Black Sea ignite?” In Literaturnaya gazeta at the beginning of 1990. The article even offered a rather absurd idea to pump water from the depths of the Black Sea containing hydrogen sulphide in high concentration, for use as fuel, while receiving manganese and silver. If the project is abandoned, the level of hydrogen sulfide contamination will rise, the newspaper said, and when hydrogen sulfide comes to the surface, the Black Sea will burn with all the inhabitants in the coastal areas.
Of the variety of hypotheses about the causes of the appearance of hydrogen sulfide in the Black Sea, two were distinguished: organic and inorganic. The followers of the inorganic concept believe that the overwhelming mass of hydrogen sulphide comes from the depths of the Earth through the bottom of the Black Sea. Adherents of the organic – believe that the entire mass of hydrogen sulphide is formed due to biochemical processes.
Some adherents of the organic concept even claim that hydrogen sulphide is the result of the emergence of a new, life-threatening form of life based on completely different biochemical processes. They are based on the process of decay, as a result of which hydrogen sulphide is released. Oxygen kills a “putrid” life, but for us hydrogen sulphide is fatal – therefore, these two forms of life are absolutely incompatible.
Perhaps the increase in the volume of hydrogen sulphide is a sign of the rapid development of new microorganisms. After the Chernobyl catastrophe, there was a significant contamination of the Black Sea with radionuclides, after which a dangerous trend was observed to increase the boundary of the hydrogen sulfide zone and its abnormally high position (50-60 m) in certain areas. Thus, over 20-30 years, this border has risen by about 40 meters. It is not known what it can lead to …
In any case, splashes of hydrogen sulfide in the upper, oxygen-enriched waters are fraught with the mass death of marine life. And such cases have already been: in the early 1950s in the Bay of Walvis Bay, in South West Africa, the current blew a hydrogen sulphide cloud from the depths of the surface. On the coast, up to 40 miles deep into the continent, the smell of hydrogen sulfide was felt, the walls of the houses darkened. Hydrogen sulphide is also toxic to humans, the smell of it already means exceeding the maximum permissible concentration.
In the Black Sea, too, such phenomena are possible, although, with a fairly rare combination of meteorological and oceanological factors (for example, with a tornado). To predict such splashes, special and constant observations of the hydrogen sulphide zone are needed.
The most unpleasant thing is that a significant factor detrimental to the oxygen zone of the sea is human activity. Hydrogen sulfide balance is under the strong pressure of human activity. Annually in the oxygen zone of the sea comes about the same amount of pollutants as hydrogen sulfide is oxidized by atmospheric oxygen. Many industrial, domestic, drainage drains of irrigation fields enter the northwestern shallow part of the sea. The Danube and the Dniester – the main feeding rivers of the Black Sea each year increase the inflow of pollutants.
In fact, the Black Sea is “shallow”, since the oxygen zone on average keeps at a depth of about 150-160 meters. In this shallow seas at this level there is a firm bottom, and in Black instead of it there is a shaky boundary of the hydrogen sulphide zone, which greedily absorbs oxygen. Therefore, our main resort sea is so sensitive to external pollution.
But against the backdrop of all this, there is good news – scientists once again took up the study of these processes. The equipment for such studies is constantly being improved, which means that there will be much more information for taking any precautions. Perhaps this process can be slowed down, or it will slow down in a natural way – it is impossible to predict at this time.