“Bulgarian Science” ask Violin Raykov, associate professor at the Institute of Oceanology at the Bulgarian Academy of Sciences, about the increased fears of pollution of the Black Sea after the explosion of the Kakhovka hydroelectric power station in Ukraine. Associate Professor Raykov shares with “BG Nauka” what the data from the measurements of pollutants in seawater show so far.
After the research vessel of the Maritime School was handed over to the Regional Inspectorate for the Environment and Water, a very thorough monitoring of more than 25 stations along the entire Bulgarian Black Sea coast was carried out. Not only the water, but also the sediment are taken as samples, and the fish are also examined. The results of measurements for heavy metals, polyaromatic hydrocarbons, cesium-137, which is radioactive, and a number of other elements are already ready. All of them are within the norm, even far below the permissible norms that the European Union has determined, reports Associate Professor Violin Raikov.
Apart from the Basin Directorate of the Black Sea Region, they carry out their own monitoring, which they regularly publish on their website. Their research shows that there are some places where waste water is discharged, such as a private zoo in Varna, whose waste water goes directly into the sea; near Kavarna and Balchik, an increase in nitrogen and copper was found. All the other elements that are measured, and they are many in number, plus the microbiological monitoring (of Escherichia coli, salmonella, etc.), show that the levels of all of them are low and within the norms and do not differ significantly from those before the accident in Kakhovka, that is, should not cause any worries.
Indeed, a huge amount of the polluted waters from Kakhovka poured through the mouth of the Dnieper into the Black Sea, but they ended up in the Odesa Bay and until now only circulate there. This is a fairly large bay, in which natural eddies of the water occur, due to which the spilled water mass, along with the entrained mud, industrial pollutants, animal carcasses and others, has largely remained there. Only a small part drifted slightly outside the Gulf of Odessa, but did not even reach the Romanian coast, and gradually settled to the bottom.
In addition, as a barrier to the movement of these waters to the south, there is a masking effect of the Danube River. The inflow of the Danube is much larger than that of the Dnipro, and after its confluence with the Black Sea it forms an underwater river in the sea, which acts as a curtain, or natural threshold, against the rest of the waters which the currents bring from the north to the Romanian coast.
In Odesa, the samples showed an increase in Coli-titer (an indicator for evaluating the bacteriological composition of water), as well as in various elements, mainly of an organic nature (such as nitrogen and phosphorus), which came from agricultural yards, from fertilizers and from toilets. But this is exclusive to this area only.
Some point pollution from discharges, some of which are legal, some of which are not, have been identified along bulgarian coast. But there is really no danger to the health and life of people, nor to fish or mussels.
To the worries and rumors that there is still pollution, even radioactive, as a result of Kakhovka, Associate Professor Raykov responds by saying that a large number of organizations (including foreign ones) are constantly monitoring for pollutants in seawater and there is simply no way to hide or miss it a serious pollution of our Black Sea. For two months since the accident, measurements have been taken, in which nothing wrong has been observed, the data from them are clear and categorical and are published freely on the website of the Ministry of Internal Affairs and Communications, for anyone who wishes to follow their updates.
Another indication that all is well with the fauna and flora in the sea is that aquaculture producers continue to export their catch. Bulgarian companies export various species, such as rapan, turbot, sprat, etc. In order for their goods to be approved for export, they need a quality certificate that they are not contaminated with anything. They pay for these analyzes in accredited private laboratories, which, along with state institutions, do not detect anything wrong. Finally, foreign food quality inspectorates also analyze the entrance from where this commodity is received before releasing it to the market in their countries.
Of course, all this does not mean that our sea is crystal clear, we have already noted that there is some local pollution. No one can guarantee that the measured values will be within the norms in the future – the ecosystem is still dynamic, human activity is active and pollution is always possible, but they are detected in a timely manner through the constant monitoring carried out by the institutions.
What can certainly be said is that at the moment there are no reasons for bathing and fishing to be prohibited or restricted at any location on the Bulgarian coast. So there is no reason to fear for people’s health, business or tourism.
Text: Radoslav Todorov special for “Bulgarian Science”
Images: canva.com, Novosti Donbass
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