Ocean Acidification in the Baltic Sea

Monitoring data from the Baltic Sea off the coasts of Sweden and Finland indicate that ocean acidification is continuing to worsen. Emissions from shipping fuel and ballast water discharges, combined with direct discharges of domestic sewage from coastal cities, as well as excessive levels of microplastics and sulfides, have led to a sharp decline in the populations of commercially important fish species such as cod and herring, and the expansion of oxygen-depleted zones in the ocean.