Nutrient enrichment of a lake will cause

• eutrophication

• stratification

• biomagnification

• bioaccumulation

A.

eutrophication

Eutrophication is an increase in the concentration of chemical nutrients in an ecosystem to an extent that increases the primary productivity of the ecosystem.

Stratification is a system or formation of layers, classes or categories. In ecology, it refers to the vertical layering of a habitat or the vertical arrangement of vegetation in layers.

Biomagnification is the increasing concentration of a substance, such as toxic chemical, in the tissues of tolerant organisms at successively higher levels in a food chain.

Bioaccumulation is the accumulation of substances such as pesticides or other chemicals is an organism.