Eutrophication occurs when excess nutrients are supplied to a region, leading to an algae bloom and ultimately A) ocean deoxygenation
B) coral bleaching
c) ocean acidification
D) overfishing

A) ocean deoxygenation

Explanation:

Eutrophication (eutrophication) begins when fertilizers (usually washed away by rain) reach the water from fields and other agroecosystems. Fertilizers are rich in phosphates and nitrates, which are otherwise a limiting factor for the flourishing of life in water.

With an excess of these salts, plants, especially algae, often begin to flourish. Then the number of dead algae increases, which are then decomposed by saprophytes, consuming oxygen. Thus, the concentration of oxygen in the water decreases, and thus there is suffocation and mass death of aquatic organisms that consume oxygen in the process of respiration.

one

Step-by-step explanation: