What is one of the effects of organic pollution on the receiving stream?

Organic pollution can significantly impact the health of receiving streams, and one of its primary effects is the decomposition of organic materials, which in turn lowers dissolved oxygen (DO) levels. When organic waste enters a stream, bacteria and other microorganisms begin to decompose this material. This decomposition process requires oxygen, leading to a reduction in the available DO in the water.

Dissolved oxygen is vital for the survival of aquatic organisms, including fish and other wildlife. As the oxygen levels drop due to the high demand created by the decomposition process, conditions become less favorable for these organisms. Low DO levels can lead to hypoxic conditions, which can be detrimental or even lethal to fish and other aerobic (oxygen-requiring) aquatic life.

In contrast to the correct answer, options suggesting increased clarity, reduction in biodiversity due to growth suppression, or enhancement of potable water quality generally do not accurately reflect the immediate consequences of organic pollution in a receiving stream. Clarity may actually decrease due to suspended particles and microorganisms. While some organisms might initially thrive, over time, the overall health of the ecosystem diminishes due to oxygen depletion, thus influencing the growth of aquatic organisms negatively and affecting overall water quality.