The section of a stream characterized by the absence of fish and found downstream of the release of oxygen-demanding wastes and heat is called the
A) clean zone.
B) decomposition zone.
C) septic zone.
D) recovery zone.
E) none of these answers

Question

Quizplus · Accepted Answer

The release of oxygen-demanding wastes and heat from human activities such as sewage discharge, industrial effluents and thermal pollution can cause a decrease in dissolved oxygen levels in the water, leading to the death of fish and other aquatic life. This depleted section of the stream is known as the septic zone where the water quality is low and the breakdown of organic matter is high, leading to a decrease in biodiversity. The clean zone, on the other hand, refers to the upper section of the stream where the water quality is high, dissolved oxygen levels are adequate, and aquatic life is abundant. The decomposition zone is where organic matter is decomposed by microorganisms, while the recovery zone is where the stream begins to recover from the effects of pollution and environmental stressors.

The Section of a Stream Characterized by the Absence of Fish