Fishes in the Baltic sea are contaminated with poison chemical and were not consumable for pregnant women. Untreated sewage flows into Neva river and to Baltic, the chemical encourage growth of algae and plankton which prevent/block sunlight from reaching sea, hence there will be a lack of oxygen in the sea.
Fishing is Sweden main source of income, more fisherman + less reproduction = no more fish. A waste water plant is needed but this project was put back due to the cost. Most of the people are throwing unfilterd waste into the river, while some illegally dump waste product into the river. Irresponsible act from St Petersburg citizens has affect the Sweden living.
The treatment plant must be build as soon as possible to prevnt any further destruction on the river.