#GREATER THAN LESS THAN EQUAL TO DIE FREE#

These organisms use DO to decompose organic material at the bottom of a body of water. Microbes such as bacteria and fungi also require dissolved oxygen. Bottom feeders, crabs, oysters and worms need minimal amounts of oxygen (1-6 mg/L), while shallow water fish need higher levels (4-15 mg/L)⁵. The amount of dissolved oxygen needed varies from creature to creature. Fish and crustaceans obtain oxygen for respiration through their gills, while plant life and phytoplankton require dissolved oxygen for respiration when there is no light for photosynthesis 4. These organisms use oxygen in respiration, similar to organisms on land. Non-bonded oxygen molecules in waterĭissolved Oxygen and Aquatic Life Dissolved oxygen is important to many forms of aquatic life.ĭissolved oxygen is necessary to many forms of life including fish, invertebrates, bacteria and plants.

#GREATER THAN LESS THAN EQUAL TO DIE FREE#

One can imagine that free oxygen molecules dissolve in water much the way salt or sugar does when it is stirred ². Dissolved oxygen is the presence of these free O2 molecules within water.The bonded oxygen molecule in water (H2O) is in a compound and does not count toward dissolved oxygen levels. Non-compound oxygen, or free oxygen (O2), is oxygen that is not bonded to any other element. A dissolved oxygen level that is too high or too low can harm aquatic life and affect water quality. In limnology (the study of lakes), dissolved oxygen is an essential factor second only to water itself ¹.

It is an important parameter in assessing water quality because of its influence on the organisms living within a body of water. Dissolved oxygen refers to the level of free, non-compound oxygen present in water or other liquids.

Greater than less than equal to die