Oxygen is essential for cellular respiration in most organisms. In an aquatic environment, oxygen availability is influenced by a variety of chemical and physical factors.

	Temperature: As water becomes warmer, its ability to hold oxygen decreases.
	Photosynthetic activity: In bright light, aquatic plants are able to produce more oxygen.
	Decomposition activity: As organic material decays, microbial processes consume oxygen.
	Mixing and turbulence: Wave action, waterfalls, and rapids all aerate water and increase the oxygen concentration.
	Salinity: As water becomes more salty, its ability to hold oxygen decreases.

Continue to Ideal Conditions for Maximum Dissolved Oxygen.