Dissolved Gases in Water.
No naturally occurring body of water is free of dissolved gases.
Their spatial and temporal distribution is dependent on factors such as precipitation, inflow and outflow, physical factors like temperature, movement of water and chemical factors such as solution processes, combination and precipitation of reactions, complex formation etc.
Among the dissolved gases present in water, oxygen and carbon dioxide are direct indicators of biological activity of water bodies.
Dissolved Oxygen is used for respiration by aquatic plants and animals.
Dissolved Carbon Dioxide is used for photosynthesis by aquatic plants.