More jellyfish but fewer mussels – the expected spread of ocean acidification can have major effects on species composition in the Baltic Sea. It may also make the water slimier and less attractive for swimming. To protect unique ecosystems and future food production, carbon dioxide emissions must be dramatically reduced and measures must be taken against eutrophication, overfishing and releases of hazardous substances.
It is now well known that the world’s large-scale emissions of greenhouse gases are leading to climate change and global warming. However, there is less awareness of what has been called “the other carbon dioxide problem” – ocean acidification.
In the 1980s, acidification of soil, watercourses and lakes was one of the environmental problems attracting most attention. Emissions of sulphur and nitrogen oxides from combustion processes (e.g. in motor vehicles and power and heating plants) was giving rise to precipitation of sulphuric and nitric acids. This was popularly called “acid rain” and had major effects on lake and forest ecosystems. However, in the 1980s and 1990s, a combination of greatly improved emission control and the liming of lakes and waterways resulted in decreased acidification in the Baltic Sea area.
In its stead, another type of acidification has attracted attention in recent years – global ocean acidification. This is caused by massive emissions of carbon dioxide and cannot be solved by liming. Up until now, the changes have not been large in the Baltic Sea. However, in the long run, this acidification will have effects here too and, eventually, threaten the sea’s ecosystems.
Gustafsson E. & Winder M., 2020. Emerging ocean acidification threatens Baltic Sea ecosystems. Stockholm University. Policy Brief.