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Therefore, human causes of eutrophication include the use of agricultural fertilizers. Other causes include sewage and aquaculture, which is the growing or farming of fish, shellfish and aquatic plants. Wastewater from certain industries and burning fossil fuels can also contribute to eutrophication.
Pollutants from these sources can cause marine eutrophication, whereby the ecosystem receives too many nutrients, triggering massive algae blooms, which eventually die and are broken down bacteria. In breaking down the algae blooms, the bacteria consume excessive amounts of oxygen, starving the marine system.