Challenges to the Baltic Sea

These are seven threats to a healthy sea.


1. Fertilization

The dung from animals is rich in nutrients, Nitrate and Phosphate used by plants to build themselves. For hundreds of years people have used the manure from cows and pigs to fertilize fields and get bigger crop yields. But when the animal farms grow bigger, the use of manure often simply increases, although few fields actually need more nutrients.

Without surrounding wetland and swamps, there are only one way for the excess nutrients to go. The rain that sprinkles the field with water washes away the fertilizers into the surrounding streams and rivers which eventually end up in the Baltic.

None of the water is treated and in some areas the nutrient load can be so high that it is by itself harmful even for plants. In the Baltic it is diluted and bring algal blooms of cyanobacteria and filamentous threadlike algae cover the rocks and smothers the kelp.

2. Treatment

Just like the farm animals, we people produce an immense load of waste. Every time we go to the toilet the sewers are filled with nutrients and water that need to be treated in a water treatment facility before it can flow on into nature.

In many places around the Baltic the treatment facilities are too small or too ineffective to handle the load of sewage water it has to cope with. This is becoming more of a reality in cities that are growing, where more people share the original existing treatment facility. The treatment is incredibly important, but in many ways also the easiest way to slow down the problem. With an increased load of water from rain and snow, more water is led through the sewers and down to the treatment facility. Although much have been done, there is an urgent need to expand many facilities for the future.

3. Nitrate

Nitrogen is essential to plants, it is used as building blocks for tons of substances that the plants need both to grow, but also to keep grazers away.

Plants in nature are limited by the amount of nitrogen available to them. Although there is nitrogen in the air, plants can only use it in a form called Nitrate. If you increase the amount of Nitrate available to plants they will grow faster and a field may produce more, which is the basic idea behind fertilization. When plants cannot use up all the Nitrate, the excess runs off with rainwater and gets spread out in nature. Since Nitrate is soluble in water, it soon ends up in streams and rivers reaching lakes or the Baltic. In the sea, algae starts to bind it and grow, causing algal blooms.

4. Phosphate

Phosphorus is another quite essential nutrient that plants need, and as with nitrogen, it is only available for plants to use in certain forms, these are called Phosphates.

Plants use Phosphates to build their cell membranes, but also as a form of energy, just like we people do. Phosphates can also rise to levels so high that plants are unable to use all of it and it goes the same way as the nitrate, down the rivers and into the sea. In the brackish water of the Baltic, there is a cyanobacteria that more resembles and algae than anything else, because it can photosynthesize.

What is special about this cyanobacteria compared to the algae is that it can use Nitrogen from the air instead of being dependent on the water born form of Nitrate. It is therefore not limited by nitrogen, but it is instead limited by Phosphate.

When the Baltic wasn’t eutrophic the cyanobacteria didn’t cause blooms as extensive as those today but with the Phosphates running down into the sea from every river, the blooms smother the Baltic during the summer.

5. Algal Blooms

Plants are essential for life in the sea and on land, wether they are algae, ferns or trees. They contribute with oxygen production and increase biodiversity by becoming habitats for other organisms and feeding a large variety of creatures.

With more algae in the Baltic, wouldn’t that be beneficial to the animals that eat them? Some animals can indeed feed on the algae, small copepods and amphipods, small shrimp like creatures common in all waters. Although the algae provide food for the small crustaceans, the seasons in the Baltic vary and when winter comes, a lot of the algae is still there and without sunlight they die. Once they are dead they end up on the bottom where bacteria start to decompose of them, but by doing so the bacteria also use valuable oxygen. With more algae to decompose, the oxygen eventually runs out.

6. Dead Zones

A seafloor without oxygen cannot sustain much life. The animals that would live there need oxygen to breathe, just like us, and without it, they too would die.

Without digging animals like worms and snails, the mud itself becomes anoxic, depleted of oxygen. The only organisms capable of a life there are Sulphur bacteria. They can break down plant and animal matter without the use of oxygen, creating poisonous hydrogen sulfide with the smell of rotting eggs in the process. They extend all across the bottom and form a white slimy carpet over the black dead mud, restricting life for all other organisms.

7. Animal Farming

On some pig farms around the Baltic there are more than 30.000 pigs. Most of them live short lives where they are grown big enough for slaughter and end up as bacon, pork or ham on our tables.

Their manure is used for fertilizing the fields surrounding the farm, sometimes to grow food for the pigs themselves. Back in the day the farms used to be self sufficient and small but today most of them are owned by national corporations that wants to see big profit come out of the food production industry. To maximize gain while keeping costs low is easier when spreading your waste around the farm instead of spending money to treat it.

Many farms that raise cows and chickens face the same problems as the pig farmers. It is hard to keep many animals in a small space while still making sure they are ok. Time and time again reports pop up in the media of the horrible conditions many animals are raised in.