Dissolved Oxygen

The stream system both produces and consumes oxygen. It obtains oxygen from the atmosphere and from plants as a result of photosynthesis. Running water, because of dissolves, its churning more oxygen than still water, like as which in a reservoir behind a dam. Respiration through aquatic animals, decomposition and several chemical reactions consume oxygen. Fish, plants, invertebrates, and aerobic bacteria all require oxygen for respiration. Many of the dissolved oxygen within water come from the atmosphere. Oxygen is distributed by current and turbulence after dissolving at the surface. Algae and rooted aquatic plants also deliver oxygen to water by photosynthesis. The major factor contributing to changes in dissolved oxygen levels is the build-up of organic wastes. Wastewater from sewage treatment plants frequent contains organic materials, which consumes oxygen. Other sources of oxygen-consuming waste involve stormwater runoff from farmland or urban streets, failing and feedlots septic systems. Depletions in dissolved oxygen could cause major shifts in the kinds of aquatic organisms found in water bodies. Temperature, pressure and salinity affect the dissolved oxygen capacity of water. A ratio of the dissolved oxygen content (ppm) to the potential capacity (ppm) provides the percent saturation that is an indicator of water quality.