Baltic Sea Portal

Ask questions about the Baltic Sea, and the editors of the Baltic Sea Portal will find out the answers. Questions can be sent to the Baltic Sea Portal using the feedback form, or by calling the editors.

1. Is the Baltic Sea in a worse state than other oceans?

The Baltic Sea is among the most polluted seas of the world. It is veryvulnerable for the following reasons, among others: shallowness, smallvolume of water and poor exchange of water. Only occasionally,depending on the weather, does salty water flow into the Baltic Seathrough the Danish Straits in the form of salt pulses. Several rivers bringfresh water into the Baltic Sea. River water contains a lot of nutrients,such as nitrogen and phosphorus. The Baltic Sea run-off area is hometo over 85 million people. Human activities such as domestic sewage,farming, industry, traffic, and energy production add to the load of theBaltic Sea.

2. What are the worst threats?

Eutrophication is considered the worst threat at the moment. Otherthreats include noxious chemicals, oil spills and accidents.

3. How could an individual aid the well-being of the Baltic Sea?

Many actions which are beneficial to the environment in general arealso helpful to saving the Baltic Sea. Avoid using private cars andwashing powder containing phosphates. Don't eat trout grown in theBaltic Sea. Eat organically grown foods when possible. Wash carpetsinland instead of close to the water. When boating, empty the septictank and other rubbish in the appropriate place in harbour. Farmers canset aside waterway protection zones between their fields andwaterways.

4. Which part of the Baltic Sea is in the worst state?

The Gulf of Finland is the most eutrophied area, with occasionally largeanoxic (? oxygen free) areas on the seafloor. The deepest zones of theBaltic, around Gotland Island and Landsort, are also affected by a lackof oxygen in the seafloor.

5. What are the most important means of protection?

Decrease the nutrient load (clean up sewage and decrease pollutionby farming, traffic and industry). Oil and noxious chemical spilllegislation should be improved and enforced. With individual species,even practical protection activities play a role, for instance winterfeeding of marine birds of prey.

6. Can we do anything about damage already done?

The Baltic Sea cannot be improved upon in the same way as inlandlakes (oxygenating, dredging or fishing unwanted "trash fish"). Thevolume of water is too great for that. The oxygen content in the deepsvaries even naturally, due to water exchange, shallow bottom areasbecome anoxic through eutrophication and the increased biomasscaused by it.

7. Are waterspouts normal in the Baltic Sea?

Small cyclones and waterspouts occur occasionally in the Baltic Sea, although they are much smaller than tornados above oceans elsewhere. More information about them can be found at the Finnish Meteorological Institute website.

8. Are there any species unique to the Baltic Sea?

No. The Baltic Sea is a very young sea in evolutionary terms. Therehasn't been enough time for species differentiation to take place. TheBaltic Sea is continuously visited by new species, some of which aresuccessful while others fail. The brackish water sets limits on speciesadaptation: it is too salty for freshwater species, and not salty enoughfor saltwater species, and there are very few species specificallyadapted to brackish water.

9. Where do blooming algae come from in the summer?

Microscopic phytoplankton is present all the time, even in winter. If theamount of algae is small, it is impossible to see them with the nakedeye. Some algae can even - in addition to the growing form - grow cellswhich can stay alive in the seafloor for months or even years. Whenthere is sufficient nutrients and light, as well as little zooplankton whicheats phytoplankton, the algae can reproduce quickly. Warm and calmweather is also needed for algal bloom mats to form on the surface.

10. What is the difference between the definitions of sea and lake?

Some international encyclopedias claim that there is no unambiguous definition. On the other hand, according to some Finnish encyclopedias, a sea is a contiguous area of salty water surrounding the continents. In addition to the obvious oceans, other sea areas include waters which are connected to the oceans either directly (bays) or via sounds (such as the Mediterranean Sea and the Baltic Sea). Salinity alone is not sufficient to fulfill the requirements of the definition of sea. The Caspian Sea and the Dead Sea are lakes, in spite of their names.