What is the Dissolved Oxygen indicator?
The amount of oxygen that is dissolved in the water column is displayed on this indicator. This is one of the most important indicators of water quality; if the amount of oxygen is too low, marine animals are either going to move away, or die for lack of oxygen. Dissolved oxygen enters the water from the atmosphere and as a byproduct of photosynthesis by phyotoplankton. Typically the surface waters have a higher concentration than bottom waters. Low dissolved oxygen at the bottom occurs when the consumption of oxygen by bacteria feeding on dead marine organisms exceeds the amount of oxygen mixed down to the bottom by wind, waves, and tides. This usually happens after a sudden plankton bloom at the surface and/or very strong vertical stratification in the water column which restricts mixing.
