Average DO All Lakes 1990-2014

Aquatic animals need dissolved oxygen (DO) to live.  Fish, invertebrates, plants and aerobic bacteria all require oxygen for respiration.  The amount of oxygen that can be dissolved in the water is reduced with increased temperature.  The temperature effect is compounded by the fact that living organisms increase their activity in warm water, requiring more oxygen to support their metabolism. Fish and invertebrates that can move will leave areas with low DO.

DO levels < 3 ppm are stressful to most aquatic organisms.

DO levels < 2 ppm will not support fish.

DO = 5-6 ppm is required for growth and activity of most aquatic organisms.