When are estuaries classified as eutrophic?

1 Answer
Apr 7, 2017

When they show huge algal growth

Explanation:

A principal cause of eutrophication is runoff of fertilizers containing remarkable amounts of nitrogen and phosphorus (mainly phosphorus). These chemicals pollute water bodies and are carried downstream in running waters to accumulate in estuaries (deltas) and other marine areas.

Estuaries are coastal zones where fresh water from running waters mixes well with salt water (of the seas or oceans). They are often regulated or partially stopped areas. Because estuarie areas are often located at the mouths of running water bodies, they are specifically sensitive to eutrophication caused by runoff containing fertilizers and other pollutants.

Dead zones might occur when eutrophication occurs. Algal growth is initial indicator of eutrophication.