Hobbies And Interests
Things You'll Need
Instructions
Collecting Your Sample
Locate a riffle in the water course under investigation. A riffle is a short, shallow section of stream. Wearing wading boots, walk out into the stream and position the kick net against the bed of the stream, with the mouth of the net pointed upstream. Have an assistant lift up the stones and dislodge the mud beneath by kicking the mud.
Allow the current to carry dislodged organisms into the net for three minutes. Wash any mud through the mesh of the net and collect the organisms in the corner of the net. Turn the net inside out and collect all the organisms in a sampling jar. Add some water from the stream if you will be returning the animals back to the river. Otherwise, cover the animals in preserving ethanol.
Take at least three samples from various points across the sight. The more samples you take, the more accurate your study. However, should you remove a great deal of fauna from the sight, it is best that you return them alive when the study is concluded.
Analyzing the Sample
Pour the contents of each sample jar into a separate tray. Separate and identify each of the organisms of fauna. Use the species identification cards from the Resources section.
Determine how many of each of the groups of organism from the Trent Index are represented in your sample (see notes on table 15.4 from Water Quality Assessments in the Resources section). A single individual from the group is enough for the group to qualify as being represented.
Using the number of groups, count along the top, horizontal axis of table 15.4 from Water Quality Assessments in the Resources section. Work down the two columns on the left side of the table until you find a label that describes your sample. Cross reference this on the table with the number of groups on the horizontal axis. The number you find is a score from 1 to 10 of the cleanliness of the river, with 10 being the cleanest.
Return live animals to the water once cataloging has been done.