Assume you are vacationing by a small lake, where you intend to do some fishing. When you arrive at this lake, you notice a slight sulfur smell. Which phase of cultural eutrophication does this sulfur smell indicate?
A) An algal bloom.
B) Anaerobic bacteria are decomposing the aerobic organisms.
C) Aerobic bacteria are decomposing the algae.
D) Fish have died from lack of oxygen.
E) Insect populations in the lake are dying off.

Question

Quizplus · Accepted Answer

The sulfur smell indicates that anaerobic bacteria are decomposing aerobic organisms in the lake. This is a symptom of cultural eutrophication caused by excess nutrients, such as nitrogen and phosphorus, which stimulate algal growth. As algal blooms die and sink to the bottom, they are decomposed by bacteria, which consume oxygen and create anoxic conditions that favor anaerobic decomposition. The byproducts of anaerobic decomposition include sulfur compounds, such as hydrogen sulfide, which produce the characteristic smell.

Assume You Are Vacationing by a Small Lake, Where You