What Natural Processes Increase Dissolved Oxygen Levels?
• Faster moving water holds more oxygen than slow or standing water. Turbulence or splashing whitewater falling over weirs, dams and rocks traps air into the water, increasing dissolved oxygen levels. • The mixing of water from top to bottom in a river ensures that oxygen levels are fairly constant no matter what the depth. • Water temperature can affect dissolved oxygen levels. Cold water is capable of holding more oxygen than warm water. • Increasing barometric pressure can force more oxygen into solution. This effect is also accomplished with decreasing altitude. Water at lower elevations is under greater pressure and contains more dissolved oxygen. Biotic Factors That Increase Dissolved Oxygen • Photosynthesis by aquatic plants and algae adds oxygen into water during daylight. Bubbles of oxygen gas can actually be seen clinging to and rising from submerged leaves under direct sunlight. During photosynthesis, plants use sunlight in a reaction with carbon dioxide and water. The resul
