How does an algal bloom cause eutrophication of a water body? Name the weed that can grow in such a eutrophic lake.

Explanation

Algal bloom in the lake or any other water body forms a scum. The scum depletes the oxygen in the water leading to foul smelling of the water body. The oxygen depletion affects the aquatic life adversely resulting in the death of fish and ultimately the eutrophic lake itself dies. Eicchornia crassipes/water hycinth grows in a eutrophic lake.