Water pollution in the Fraser River has many sources. Resource-based economic activities located close to the Fraser River include agriculture, mining, logging, and hydroelectric developments. Water quality in the river can be degraded because of these industrial activities, municipal and urban waste water, and individual polluters. Poor water quality affects the habitat of the flora and fauna in the river, and certain pollutants can cause cumulative effects such as pollutant bio-magnification. Excessive nutrient build-up in the river can lead to eutrophication, where bacteria feeding on organic material can significantly reduce the oxygen content of the water and essentially suffocate fish and other fauna.