Dissolved Oxygen Pt. 2

October 1—List two sources of dissolved oxygen.  Explain the cycle of oxygen and carbon dioxide in an aquatic ecosystem.  How does time of day affect the amount of dissolved oxygen?

Dissolved oxygen comes from contact with the atmosphere and plants.
Plants and other producers use carbon dioxide in photosynthesis. They produce oxygen as a waste product. Carbon dioxide moves from the air into the leaves of plants. Oxygen moves from the 
plant into the air through the leaves. 

The amount of dissolved oxygen is dependent on the plants photosynethesis cycle, dissolved oxygen is highest during the day because the sun gives energy to the plants to complete photosynthesis and create dissolved oxygen. At night, photosynthesis is ceased and the level of dissolved oxygen decreases, and the cycle repeats.