What issue can arise from low oxygen levels in waterways?

Low oxygen levels in waterways can significantly harm aquatic life, leading to decreased health among various organisms. Aquatic life, including fish, invertebrates, and microorganisms, relies on dissolved oxygen in the water for respiration and survival. When oxygen levels drop, these organisms may struggle to obtain the necessary oxygen to sustain themselves, resulting in stress, reduced growth rates, reproductive issues, and even mortality.

Additionally, lower oxygen levels can lead to the alteration of the ecosystem's balance, favoring the growth of anaerobic bacteria over aerobic organisms, which further degrades water quality. Consequently, a decline in aquatic life health can disrupt the entire aquatic ecosystem, affecting food webs and ultimately leading to a less biodiverse environment.

In contrast, increased recreational activities, improved water temperature, and enhanced photosynthesis are generally positive outcomes for waterways and their ecosystems, but these can be adversely impacted by low oxygen levels.