Question

The overgrowth of algae on the surface of this water is caused by

Answer 1

Answer:

Some algal blooms are the result of an excess of nutrients (particularly phosphorus and nitrogen) into waters and higher concentrations of these nutrients in water cause increased growth of algae and green plants. As more algae and plants grow, others die.

Explanation:

Answer 2

Answer:

The answer is C.  an increase in nitrogen levels in the water from fertilizer runoff

Explanation:

The overgrowth of algae on the surface of this water is caused by an increase in nitrogen levels in the water from fertilizer runoff.