How is dissolved oxygen important for fish?

Dissolved oxygen is crucial for fish primarily because it is essential for their respiration. Fish extract oxygen from water through their gills, a process that is vital for their survival. Oxygen is involved in cellular respiration, which is how fish produce the energy they need to perform all their biological functions, including swimming, feeding, and reproduction.

Without sufficient levels of dissolved oxygen, fish cannot effectively carry out these essential functions, leading to stress or even death. This makes the availability of dissolved oxygen in aquatic habitats a key factor for healthy fish populations and overall ecosystem functioning. Understanding this principle is fundamental for anyone involved in water quality management and conservation efforts.