Water Quality Invertebrate Assessment

Biological assessments of water ecosystems is also a terrific indicator of the water's quality.  Certain invertebrates are called indicator species as they indicate the quality of an environment. These species usually have critical environmental requirements in order to survive.  For instance, some species need very clean water in order to survive such as high dissolved oxygen. Others can live in very poor water quality such as low dissolved oxygen.  Whichever species is in excess will determine the water's quality.

Lesson Objective:  To determine the quality of Bighill Creek by identifying the species present in the ecosystem.

DO Picture BOD Picture BOD Graph Invertebrate Sampling



Click on upper left picture which links to a website outlining BOD and DO.
Click on upper right photo which links to a website giving a more distinct comparison between BOD and DO. 


1.  Click here to download invertebrate field study smartboard presentation. 

2.  Go to Bighill creek, collect your invertebrates.  Bring your samples back to class.  Using the dichotomous keys, classify your organisms.

3.  Record your observations in the biotic table.

4.  Follow the instructions to quantify your results.

5.  Rate Bighill Creek.