microscopic organisms.

Then an identification key is used to help determine which category or group the organism belongs in and allows a numerical value be assigned to that organism. A worksheet is then used to calculate the final value or score of all the organisms found. Depending upon the worksheet's equations, the score determines the condition of the water quality.

Usefulness of macro invertebrates

Aquatic macro invertebrates have some general characteristics that make them very useful to assess stream health:
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