What is a potential environmental impact of non-perennial water sources?

Non-perennial water sources, such as seasonal rivers or streams, can significantly impact the recharge of groundwater because they do not provide a constant flow of water. When these sources dry up or experience significant reductions in flow, the input to the surrounding aquifers is diminished, which may lead to decreased groundwater levels over time. This reduction in groundwater recharge can also affect not only water availability for various uses but can also impact the health of the ecosystems that rely on consistent groundwater levels.

In contrast, maintenance of a consistent ecosystem and stability in fish populations are generally associated with perennial water bodies that provide a reliable source of water year-round. Additionally, increased water pollution may result from different factors like urban runoff or industrial discharges, but these issues are not directly tied to the characteristics of non-perennial water sources in isolation. Thus, the correct answer highlights a direct consequence of non-perennial streams on the broader water system.