what is a possible consequence of fertilizer runoff in aquatic ecosystems?

A possible consequence of fertilizer runoff in aquatic ecosystems is eutrophication. This occurs when excess nutrients, primarily nitrogen and phosphorus from fertilizers, enter water bodies and stimulate rapid growth of algae and aquatic plants, known as algal blooms. These blooms can block sunlight, harming underwater plants, and when algae die and decompose, they consume large amounts of oxygen in the water, leading to low oxygen levels (hypoxia). This oxygen depletion creates "dead zones" where aquatic life such as fish and shellfish cannot survive, causing loss of biodiversity and disruption of the ecosystem. Additionally, nutrient pollution can contaminate drinking water and release harmful toxins affecting both aquatic life and human health.