Slow ageing process during which a lake or estuary evolves into a bog or marsh and eventually disappears. During eutrophication, the lake becomes so rich in nutritive compounds (especially nitrogen and phosphorus) that algae and other microscopic plant life become superabundant, thereby choking the lake and causing it to eventually dry up. Eutrophication is accelerated by discharges of nutrients in the form of sewage, detergents and fertilisers into the ecosystem.