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Bioassessment Education Resources

Bioassessment of Florida’s Ecosystems
The public information brochure presents information on Florida's watersheds, water quality monitoring, why we study biological communities, what a bioassessment involves, how the results of a bioassessment can be used, as well as some information on bioassessments in action at the Florida DEP.

Bioassessment Educational Posters

Fact Sheets

Bugs as Indicators of Water Quality

In Florida, we use aquatic macroinvertebrates, or "bugs", to help us figure out how clean or dirty water is (to find out more, check out this poster on bugs).   In order to use bugs as indicators of water quality, we need to develop a bug "index", or number, which will tell us about the bugs we've found.  Think of an index as a grade, like you'd get on a test, where the higher the number is the better you've done or the better the water is. 

  1. Print out the bug id cards and cut them apart.
  2. Shuffle them and place them face down on a table. 
  3. Pick five cards at random and turn them over.
  4. Use the bug identification poster  to identify what bugs you're looking at.  If you have trouble understanding any of the words, look in a dictionary or check out this poster on bug parts
  5. Write down the drop number (check out the three "drips" below to see what they look like) for each bug you've identified.
  6. Add up your bug numbers, this is your bug score.
  7. Good biologists always double-check their identifications, check yours too!
  8. Want to know what your score means? 
Some bugs can't tolerate water pollution, we call these bugs pollution sensitive. 
bug ID drop number 12 Mayfly
Water Penny
Other bugs are less sensitive to pollution...
bug ID drop number 8 Crayfish                 
Riffle Beetle Larva             
Riffle Beetle Adult
Some bugs can live in any kind of water.  We call these bugs pollution tolerant.
bug ID drop number 4 Leech
Aquatic Worm
Gilled Snail
Black Fly
Lunged Snail

Last updated: September 21, 2011

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