New threats

When chemical transportation and other marine traffic increases in the Baltic Sea, the risk of a chemical spill also increases. It is estimated that in the Gulf of Finland alone the overall amount of tanker traffic could be as much as 160 million tons by 2010, and about half of the tankers would be oil tankers. There is also a threat from the barrels of poison and other waste was that was dumped in sea several decades ago.

In addition to the eutrophication affect of the risk of accident, wastewater from shipping, and exhaust gases; the wave and suction effect of shipping as well as the wake from ships causes erosion of the inner archipelago and raises nutrients and other substances from the seabed to the surface. Dredging and disposal also cause muddiness of the water and may put back into circulation substances that have already been sedimented, such as environmental poisons.

Consumer chemicals and alien species

Besides the "traditional" environmental toxins the chemical cocktail in waters has raised concerns recently; especially flame retardants, surfactants from consumer products and pharmaceuticals are found in inland waters and the Baltic Sea. Another emerging problem is the littering of the seas, and during the last years both research results and control policies on plastic debris and microplastics have been published.

Alien species that have been carried from one water system to another in vessels’ bilge water are one of the biggest threats to the biodiversity of seas. The alien species may displace original species and thereby shake up the equilibrium of the sea.

With the rapidly increasing amount of shipping, more alien species than ever before, and from different sea areas, are entering the Baltic Sea. So far over 100 alien species have been recorded in the Baltic Sea, 60 –70 of which have managed to establish themselves permanently at least in some areas of the Baltic Sea. This number is significant in relation to the small amount of species in the Baltic, due to its young age.

The number of animal species in the Baltic Sea varies from around 450 in the Kattegat to around only 50 species in the Gulf of Bothnia.

Climate change

The effects of climate change on the Baltic Sea are still partly unpredictable. However, we can assume that there will be several environmental and biological impacts as a result of, for example, a higher summer temperature, increased rainfall, and changing ice conditions.

For example, the increased rainfall and runoff caused by climate change will increase the loading and make the eutrophication of the Baltic Sea even worse than before. The impacts caused by climate change are also important in areas such as land use planning in towns and cities, and the functioning of the water supply and sewage systems.