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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.
There are two types of eutrophication: natural eutrophication and anthropogenic eutrophication. Eutrophication is widespread in freshwater ecosystems, and it plays a major role in the normal aging process of many ponds and lakes. The main cause of anthropogenic eutrophication is human activity. Nutrients from fertilized fields, lawns, and farms are deposited in rivers, streams, lakes and oceans when it rains.