Term used to characterise a lake.  This refers to a lake having an  abundant accumulation of nutrients that support a dense growth of algae and other organisms, the decay of which depletes the shallow waters of oxygen in summer resulting in death of animal life.  (Compare with Oligotrophic).

In LAWA a trophic level of 4-5 meaning the water quality is poor. The lake is green and murky, with higher amounts of nutrients and algae.