Eutrophication may only be made available again during autumn turn-over or in conditions of turbulent flow. Enhanced growth of aquatic vegetation or phytoplankton and algal blooms disrupts normal functioning of the ecosystem, causing a variety of problems such as a lack of oxygen needed for fish and shellfish to survive. The water becomes cloudy, typically coloured a shade of green, yellow, brown, or red. Eutrophication also decreases the value of rivers, lakes and aesthetic enjoyment. Health problems can occur where eutrophic conditions interfere with drinking water treatment. Human activities can accelerate the rate at which nutrients enter ecosystems. Runoff from agriculture
Cultural eutrophication Nova Scotia. In order to match an increase in food demand, agricultural production relies heavily on the use of fertilizers to increase overall crop productivity. These fertilizers contain high amounts of phosphorus and nitrogen, which results in excess amounts of nutrients entering the soil. The nutrients that are not absorbed by the plant leach out of the soil and enter freshwater systems, such as rivers. These nutrients can eventually end up in aquatic ecosystems, and are a contributor to increased eutrophication. Cultural eutrophication Cultural eutrophication is the process that speeds up natural eutrophication because of human activity. Due to clearing