A 3-hectare lake in the American Midwest suddenly has succumbed to an algal bloom. What is the likely cause of eutrophication in freshwater ecosystems, such as this one?
A) increased solar radiation
B) introduction of non-native tertiary consumer fish
C) nutrient runoff
D) accidental introduction of a prolific culture of algae
E) iron dust blowing into the lake

Question

Quizplus · Accepted Answer

Nutrient runoff from agricultural or urban areas is a common cause of eutrophication in freshwater ecosystems. Excess nutrients, such as nitrogen and phosphorus, can stimulate the growth of algae, leading to algal blooms and depletion of oxygen levels in the water.

A 3-Hectare Lake in the American Midwest Suddenly Has Succumbed