What is the minimum dissolved oxygen level required for fish to live and reproduce normally?

The minimum dissolved oxygen level required for fish to live and reproduce normally is typically between 4 to 7 parts per million. This range is crucial for the survival and health of fish species, as adequate oxygen levels are necessary for respiration and various metabolic processes.

At levels below this range, fish can experience stress, reduced growth rates, and impaired reproduction, which can ultimately lead to population declines. Different species may have varying tolerances, but generally speaking, maintaining a dissolved oxygen concentration within this range supports robust aquatic ecosystems. This is why establishing and monitoring oxygen levels in aquatic environments is essential for water quality management and the overall health of fish populations.