The Baltic Sea – special but vulnerable
The Baltic Sea is a unique natural wonder, our summer holiday haven. Gentle waves, golden sands, a breathtaking combination of pine trees and the sea – a sight that warms the hearts of many Lithuanians. But behind this idyll lies a growing ecological tragedy. More than 70 000 km² of seabed have become a death zone – a place where oxygen is almost non-existent and life barely exists. So why do the Baltic Sea have the world’s largest dead zones?
Why is the Baltic Sea so vulnerable?
The Baltic Sea is special because of its geographical features. It is almost closed, with only a narrow Danish strait connecting it to the North Sea and the Atlantic Ocean. As a result, water exchange is slow and the sea’s waters only renew themselves every 30 years.
Secondly, it is fed by many large rivers, such as the Nemunas, the Vysla and the Daugava, which bring large quantities of fresh water. Freshwater dilutes the salty ocean water, making the Baltic Sea one of the least salty seas in the world.
This low salinity creates water layering. The lighter fresh surface water ‘floats’ above the heavier salty water at the bottom, restricting oxygen circulation. Slowly changing water accumulates pollutants in the Baltic Sea for years, with increasingly dramatic consequences. Layering, together with pollutants, thus creates the perfect environment for hypoxia – an oxygen starvation that turns the seabed into a killing zone, a place where almost nothing can survive.
„Can you imagine that this dead territory is already bigger than Lithuania? This process has made the Baltic Sea a sad record holder, with seven of the world’s ten largest “death zones”
Dead zones – lost oases of life
And the third reason why the Baltic Sea has the world’s largest dead zones is because of us humans. In addition to natural factors contributing to hypoxia, the biggest impact on the Baltic Sea is caused by human activity. The great rivers also bring huge amounts of nutrients – mainly nitrogen and phosphorus. These nutrients, mainly from agricultural fertilisers and inadequately treated sewage, promote algal blooms. When these algae die and decompose, they consume oxygen, leaving bottomland ecosystems without a source of life.
Can you imagine that this dead territory is already bigger than Lithuania? This process has made the Baltic Sea a sad record holder, with seven of the world’s ten largest “death zones”. Although these zones are not yet visible off the coast of Lithuania, their spread could affect us too if the changes are not contained.
Why should it matter to us?
The problems of the Baltic Sea are not limited to environmental challenges – they affect us too. If eutrophication and hypoxia continue, it could lead to declining fish populations, mass mortalities and coastal algae masses that will not only spoil the view, but also smell terrible.
It also means that our favourite summer pastimes – swimming, seaside walks – can become nothing more than fond memories. The Baltic Sea is our shared responsibility, and its state depends on the actions of each of us.
What can we do?
Although the problem seems huge, every action we take can help the Baltic Sea recover. Here are some simple but important steps:
- A toilet is not a bin. Let’s be responsible with our waste water – put oil, grease, wet wipes and hygiene products in the bin, not down the drain.
- Let’s support organic farming. Let’s buy organic products, choose organic fertilisers and encourage the reduction of chemical fertilisers.
- Let’s do our bit for the environment. Let’s take part in education campaigns, support projects that help protect the Baltic Sea.
This sea is more than just a natural beauty – it is home to us all. Only together can we ensure that the Baltic Sea remains an integral part of our lives. Every action we take can be the difference between life and death for the sea. Are you ready to make a change?
Source: https://www.biogeosciences.net
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