Dissolved Oxygen
Dissolved Oxygen (DO) is the measure
of the amount of oxygen dissolved in the water. All living organisms,
except for certain types of bacteria, need oxygen to survive. Organisms
living in the water have the ability to use the oxygen dissolved in the
water to breathe. Too little oxygen severely reduces the diversity and
population of aquatic communities. Therefore the amount of DO in the
water is very important to aquatic life. Low oxygen can directly kill or
stress organisms such that they will not be able to successfully
reproduce or grow.
Water with less than 1 part per
million (ppm) of oxygen is considered anoxic (no oxygen present); less
than 5 ppm of oxygen is generally considered so stressful that most
coldwater fish will avoid these areas. Anoxic (low oxygen) conditions
can also promote Total Phosphorous (TP)
release from sediments.
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A Senator George J.
Mitchell Center graduate student calibrates a dissolved oxygen meter
at Abol Pond. |
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