Do you know that there is a sea that exists in the world that is alive on the top and dead at the depth of its core? That’s the Black Sea for you. It is known as the largest semi-closed anoxic basin on earth, which means that at the topmost level of the sea, there are living organisms present, but deep down, it’s dead.
Now the question is how a sea becomes lifeless at the end of it. There are different concepts, and one is that in between there is a suboxic zone, which is a thin layer between oxic and anoxic water. The reason for this layer is still not understood properly, as it has not been sampled yet.
Where is the Black Sea Located?
At first, let’s talk about the geographical location of the black sea. It lies between Europe and Asia; we can say that it is in between Eurasia. It is semi-closed and connects with the Mediterranean Sea via the Bosporus Strait and the Sea of Marmara via the Dardanelles Strait. It surrounds six countries, which are Turkey, Romania, Ukraine, Bulgaria, Georgia, and Russia.
Ukraine is in the north, Georgia is in the east, Bulgaria and Romania is in the west and turkey is in south. There are only a few small islands in the black sea. The largest island among others is the Zmiyinyy, which is part of Ukraine.
Why is the Black Sea Anoxic?
Before going forward with why everyone says that the black sea is anoxic, one should know what exactly anoxic means. Anoxia is the situation or condition when there is either a lack or complete absence of oxygen, which makes the living situation difficult.
As there is no oxygen, any living organism cannot survive there. Anoxic waters refer to the area of sea, fresh, or ground water that has a complete depletion of dissolved oxygen. In most cases, the condition is formed when oxygen is prevented or restricted from reaching the deeper levels of water bodies. Or their density is stratified because denser, colder, or hypersaline waters reside at the bottom of the basin. There are conditions where the amount of oxidation of any organic matter through bacteria is more than the available dissolved oxygen.
Many think that the anoxic condition of the black sea is because of the intense pollution, but guess what, despite the intense pollution, there are still living organisms available in the top layers of the water body. Then what is the reason for its anoxic tendency?
The black sea contains a positive water balance and has an annual outflow of around 300 km³. The total flow of water out of the Black Sea flows in two different directions. One towards the Bosporus and the second towards the Aegean Sea.
The saline water, which is denser than the Aegean Sea, goes underneath the less dense water in the black sea. This condition creates a constant layer of water that neither drains nor mixes, and it remains in the deep, therefore creating an anoxic layer. Because of this, there are many remains of ancient shipwrecks that are found preserved in the black sea.
The role of Hydrogen sulfide in the anoxic conditions of the Black Sea
Molecules of H2S (Hydrogen Sulfide) play a very important role in the anoxic nature of the black sea. Though it is considered a primary pollutant, it is also a potential source of energy generated from hydrogen. It is produced through the bacteria, which reduce sulfate in the anoxic layer of the black sea.
This poses a threat to many marine life, both flora and fauna, and can also be a source of environmental disaster. But if looked at from the point of view of producing hydrogen, it is a clean and sustainable energy source.
Negative Impact of Hydrogen Sulfide
- It is toxic to marine life, and because of this, the marine life is limited in the black sea
- It is a pollutant, thus creating an acid gas that pollutes the atmosphere.\
- It can be a cause of potential disaster that would lead to a major environmental disaster, causing major depletion of marine as well as human health.
Life in the Black Sea
It can be said that the black sea region’s natural wealth is in danger. The condition is worsening day by day because of many things. Be it pollution, oil spills, marine dependency, anoxic levels, and many more. This is creating unbearable living conditions for both land and water territories.
The region is also impacted by the constant climate change, which is adding one more factor to the depletion of the region’s natural system. Now, the environment of the black sea is at a crossroads. If it continues the negligence, it will slowly get totally disrupted. Although for changing these conditions many organizations are working and one of them is the WWF.
WWF has been partnering with the local communities and government to help in the preservation and promotion of sustainability so that the black sea can be protected.
Global Impact of the Black Sea
The black sea is an important aspect of global affairs as it influences many global activities. It influences most of the things like trade, environmental health, and even geopolitics. As there are 6 countries that surround the sea, which means it is the epicenter for trade for all those 6 countries. It has a very critical location with a unique ecosystem, and it also has a deadly impact on pollution. All these factors make this a highly valuable region globally.
If we talk about the economic factor, it is an important trade route that connects Europe with Asia and thus is a lifeline for many economic activities which has their border with the sea. The Black Sea Grain is an initiative that has a major impact on the global food markets and helps stabilize the process, and also reduces food security in many countries.
Therefore, many scientists are now going deep into the black sea and trying to figure out a solution for all the problems, but mostly the anoxic state or layer, so that the resources can be utilized up to their efficiency.
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