The Baltic Sea can be saved but action must be taken now

The Baltic Sea is the youngest sea of our planet. It formed approximately 10 000 – 15 000 years ago, after the latest ice age. The Baltic Sea’s catchment area is four times bigger than the sea itself, and it includes 14 countries and over 85 million habitants. Catchment area is the area from which surface water and groundwater flow into the sea. This is why operations done on land, such as farming and habitation, also impact the sea. The Baltic Sea has nine coastal countries: Finland, Sweden, Denmark, Germany, Poland, Latvia, Lithuania, Estonia and Russia.

The Baltic Sea is shallow compared to the oceans, and almost entirely closed. Saltwater inflows through the Danish straits occasionally bring salty ocean water to the sea. Due to massive freshwater runoff from the land and limited saltwater inflows from the Danish straits, the salinity of the Baltic Sea is much lower than that of the oceans, and it’s considered brackish water instead of sea water. This makes the Baltic Sea a challenging environment for many species, since the water is too fresh for marine species but too salty for fresh water species. Many species live on the edge of their comfort zones, and some animals are smaller in the Baltic Sea compared to their marine counterparts. Even small changes in the sea can have dramatic effects on the sea’s habitants.

Water in the Baltic Sea is stratified. Water near the surface is warmer, while colder water sinks to the bottom. These layers mix during spring and autumn, as the temperatures change. Water is also stratified as a result of different levels of salinity, due to saltier water being heavier and settling to the sea floor. Salty deep water doesn’t mix with fresher surface water, but sometimes saltwater inflows from the Danish Straits push the old deep water to the surface.

As a result of the large and heavily populated catchment area, shallowness of the sea, and the stratification of water the Baltic Sea is very vulnerable. Nutrients and hazardous substances have accumulated in the sea for centuries and are still causing problems, such as eutrophication. Large areas in the sea bottom are dead due to poor oxygen conditions. Heavy marine traffic increases the risk for accidents, such as oil spills.

Waves crashing on the shore of the Baltic Sea

Eutrophication in the Baltic Sea

Excessive amounts of nutrients increase algal growth. This process is called eutrophication, and it's a major problem in the Baltic Sea.

Ice in the Baltic Sea

Climate change effects

Rising temperatures and increased rainfall will have various effects on the Baltic Sea's condition and its habitants.

A ship making waves in the Baltic Sea

Hazardous substances

Large quantities of dangerous chemicals and other hazardous substances have accumulated in the Baltic Sea's bottom sediments.







Phosphorus (P) and nitrogen (N) along with other mineral nutrients are needed in crop production. The amount of phosphorus on our planet is limited, and the production of nitrogen fertilizers is energy intensive and accelerates climate change.

These problems could be solved by closing the nutrient cycle. Valuable nutrients must be prevented from leaking from the food chain, and recovered from household waste, food industry’s side streams, manure and municipal wastewater. Recovered nutrients could then be reused in food production. This would also improve the condition of the Baltic Sea, as these excess nutrients would no longer be washed into it.


In addition to making a Commitment or a donation there are many things you can do to help saving the Baltic Sea. When we all do something for the benefit of the sea, even small actions make a big difference. By following the tips below you can do your own part.