Asked by: Edier Beleaasked in category: General Last Updated: 14th March, 2020
Why does the level of dissolved oxygen go down after sunset?
In respect to this, why would Dissolved oxygen decrease?
Low dissolved oxygen (DO) primarily results from excessive algae growth caused by phosphorus. Nitrogen is another nutrient that can contribute to algae growth. As the algae die and decompose, the process consumes dissolved oxygen. Die-off and decomposition of submerged plants also contributes to low dissolved oxygen.
Similarly, how does temperature affect dissolved oxygen? First, the solubility of oxygen decreases as temperature increases ¹. This means that warmer surface water requires less dissolved oxygen to reach 100% air saturation than does deeper, cooler water. Water at lower altitudes can hold more dissolved oxygen than water at higher altitudes.
Just so, how does sunlight affect dissolved oxygen?
Oxygen dissolves into water from two sources: the atmosphere and from plants in the water. In the presence of sunlight, these produce oxygen through photosynthesis and release this oxygen into the pond water. At night and on very cloudy days, algae and submerged plants remove oxygen from the water for respiration.
How do concentrations of dissolved oxygen affect fish?
Dissolved oxygen concentrations are constantly affected by diffusion and aeration, photosynthesis, respiration and decomposition. There are lower dissolved oxygen concentrations near the equator because salinity is higher. Coldwater fish like trout and salmon are most affected by low dissolved oxygen levels .