The correct answers are A) Eutrophication and D) Tourism.
The factors that endangered Eastern Europe’s marine ecosystem are Eutrophication and tourism.
Eutrophication is when the seas are overload with nutrients such as nitrogen and Phosphorus and these can result in massive blooms of algae that are toxic. The algae decompose and fishes die, resulting in modification and endangered of the marine ecosystem. Another factor that endangers the marine ecosystem in Eastern Europe is tourism. People just go there and have fun but is not paying attention and leave beaches dirty. They are not taking care of the environment and the governments cannot do much because tourists leave a considerable amount of money for the countries.