I didn’t plan to write this post.
I dreamt of a beautiful Black Sea marine biotope aquarium but the ecocidal crime of russians with blowing up the Kakhovka HPP dam destroyed the tender biological balance of the northwestern part of the Black Sea.
Now I cannot dream to keep a piece of the Black Sea in my home aquarium, even more, I am afraid to even dream about the ecology of our Sea to return in faraway future to the pre-war condition.
The Black Sea ecosystem is unique and vulnerable and here’s why:
Geography
The Black Sea is an intracontinental sea of the Atlantic Ocean. It washes the shores of Ukraine, the so-called russian federation, Georgia, Romania, Bulgaria, Turkey. The Gulf of Odesa suffered the worst damage of the Kakhovka dam destruction. This gulf is located in the northwestern part of the Black Sea, within the Odesa city borders in Odesa region of Ukraine. The width of the bay is 9 km, the water depth is up to 14 m. On its shores there are located the city of Odesa, Odesa Port, the southern part of the bay is used exclusively for recreational purposes.
The northwestern part of the sea is much more influenced by freshwater income from rivers than the rest of the Black Sea. Here, the largest rivers (the Danube, Dniester, Southern Bug and Dnipro) flow into the sea on a 250 km long stretch of coast bringing water and thousands of tons of organic matter. This dependence causes significant environmental consequences: the Black Sea, primarily its northwestern part, is one of the most eutrophic areas of the world ocean.
Climate
The Odesa Bay, as well as the adjacent areas of the sea, are located in the temperate continental climate zone. Average water temperature is: in summer +19.9°C, in winter up to +2.2°C. In extremely cold winters, the sea freezes within the bay.
Hydrological and hydrochemical regime of the gulf
The vital for the biolife of the Black Sea is the Rumelia water current. It receives a momentum of movement from the flow of large rivers flowing into the northwestern part of the Black Sea – the Dnipro, Dniester, Southern Buh and Danube. Beginning near the mouth of the Dnipro-Buh estuary, the Rumelia Current moves first from east to west along the northern shores of the sea, and then south along the western shore in an about 50-75-mile strip.
Salinity and biogenic substances regime of the region are greatly influenced by sources of the large rivers freshwater runoff. Maximum river discharge into the bay occurs in the spring period (April-May). Average water salinity ranges from 15.2‰ in summer to 15.6‰ in winter. Water salinity varies from 6-8‰ at the intrusion of water masses from the Dnipro-Buh rivers estuary and up to 18‰ during western winds and rising of deep sea waters.
The hydrogen index value varies in the range from 7.85 to 8.61 pH.
The water of the Black Sea from a depth of 120-200 m is saturated with hydrogen sulfide. Its percentage content increases with depth and covers about 87% of the total volume of the sea. There is almost no life within the range of hydrogen sulfide. In connection with the strengthening of unfavorable anthropogenic factors, there is a tendency to increase the layer of hydrogen sulfide, which is dangerous for all living things.
Biology
Studies of the ichthyofauna of the Odesa Bay were started 100 years ago. At that time, there were 75 species of fish, of which 13 were freshwater.
Past history of the Black Sea and the low salinity of its waters determine the c of flora and fauna. They include:
1) ancient relic brackish water fauna, which is a remnant Pontic fauna,
2) Mediterranean (in other words, Atlantic) fauna and flora is a younger inhabitant and currently its most complete host and
3) freshwater forms.
Especially rich hydrobiont diversity is observed in shallow waters of coastal areas.
The first thing that attracts the attention of an underwater observer is the large number and variety of algae that is the main representative of the Black Sea flora. Unicellular algae cover the solid surface with a continuous green or olive-brown film, large algae, or macrophytes rise above them, this can be seen with the naked eye. These are mainly representatives of three types of algae: green, brown and red algae. The most common green algae along the Ukrainian shores of the Black Sea are Ulva species, brown algae – Cystoseira, up to 1 m high, it forms thick thickets near the shore, red algae – Сeramium and Phyllophora. The latter grows in an unattached form. It forms a huge cluster in the central part of the Black Sea northwestern shelf – the Zernov Phyllophora field, with an area of about 11,000 km.
The present animal world is rich, it is represented by many species of fish, invertebrates, mammals. Mass seasonal migrations of fish are observed at the beginning of summer when fish from the Mediterranean Sea and the southern part of the Black Sea go to the northern part of the sea and through the Kerch Strait to the Sea of Azov. In autumn fish migrates in the opposite direction to warmer waters.
My underwater video:
WAR and DESTRUCTION
The Russian war in Ukraine has been going on for more than 9 years with the full-scale invasion that they have started on February, 24 2022. The destruction of the Black Sea ecosystem russians started in 2014 when they occupied the Crimean Peninsula and turned it into their huge military base.
The war has a significant impact on the natural environment, in particular, on our seas: the Black Sea and the Sea of Azov. Due to the blocking of ports and mining of the water area, they remain almost inaccessible not only to fishermen or tourists, but also to scientists who have been studying changes in the marine environment for decades. But despite the impossibility of taking samples at sea now, based on the available data and facts, still it is possible to understand how war and military occupation affect the marine environment.
Among the main factors of the nature destruction of the sea by armed aggression of the so-called russian federation, the following can be named:
1. Sunken military ships. They destroy the seabed and pollute water with toxic substances
(russian flagship “Moscow” sank right in the middle of the Zernov Phyllophora field causing terrific consequences to this natural phenomenon)
2. Discharge of ballast water with invasive species
(ecosystem of the Black Sea is relatively new and it has no natural mechanisms to withstand dangers of new invasive organisms)
3. Blast waves from underwater detonation of ammunition
(underwater explosions cause a shock wave that spreads far away from the epicentre, stunning fish and killing other organisms (their swim bladder, filled with gas, is easily ruptured under the influence of large pressure drops from an explosion)
4. Acoustic waves from sonar devices of warships and submarines
(The acoustic frequency of cetaceans coincides with the frequency of russian military marine sonars, which damages animals’ hearing system. Dolphins rely on echolocation for most biological aspects of their lives, so acoustic trauma can interfere with foraging, reproduction and communication, as well as lead to disorientation and ultimately death)
5. Pollution of the sea surface with oil spills
(spills of oil products create a film on the surface of the sea, this thin film is impermeable to oxygen. In addition, they are toxic to the sea inhabitants, especially microscopic organisms that live in a thin water layer near the surface – neuston. This surface layer of water acts as an “incubator” for the young of many aquatic organisms. Its destruction can lead to significant changes in food chains and disruption of the entire balance in ecosystems)
6. Chemical contamination with toxic substances from ammunition
(Even rocket shells, bullets, and casings themselves are often made of toxic materials. Especially, lead (this metal is most often used in bullets and casings) can affect various organ systems of vertebrates, mostly the nervous system. Shells or debris left over from the war can also lead to poisoning of birds as they often swallow small stones to help digestion. The remains of chemical weapons and toxic substances beside the immediate effect also accumulate for years in the natural environment and continue to empoison living creatures even long after the war ends)
7. Destruction of critical infrastructure (ports, oil fields, treatment plants, landfills)
8. Creation of military bases and training grounds in protected areas
9. Mining of the bottom and coastal sea waters with russian naval bottom and floating mines
(mines can appear anywhere and anywhere and blow up taking away lives of humans and animals)
10. Construction of the Crimean bridge
(the notorious Crimean bridge between the town of Kerch in Ukrainian Crimea and Taman Peninsula in the so-called russian federation was built on the Kerch Strait. It heavily affects the water exchange between the Black Sea and the Sea of Azov through the strait and breaks the route for the migratory fishes and dolphins. Beside, the unique ecosystem of the Tuzla island was completely destroyed by the russians during the bridge construction)
11. Blowing up the Kakhovka HPP dam
(I am afraid, the Black Sea and the lands around the dam will not be able to recover to the pre-war conditions. This is the worst human caused ecocide of the current century. You can read the detailed investigation of this russian crime here: https://biotopeaq.wordpress.com/2023/06/21/dam/ )
Sources:
Black Sea Biological Diversity Ukraine. Compiled by Prof. Yu. P. Zaitsev and Dr. B.G. Alexandrov. United Nations Publications. New York 1998
Чорноморські береги України. Prof. Yu. P. Zaitsev. Kyiv. 2008
https://ecoaction.org.ua/vijna-i-more.html
http://eprints.library.odeku.edu.ua/id/eprint/2016/1/Kozma%20V.F_M_2017.pdf
Open-source intelligence data
biotope aquarium 