ENVST-Biotic Index at Pheasant Branch Creek Name:______

Today we are going to the creek to sample macroinvertebrates and calculate the biotic index. You will be working in your groups to complete this task, but you will be individually completing this worksheet.

Refer to the Directions sheet before starting and listen carefully to the directions given in class. You will be assessed on your performance at the creek and on your ability to efficiently work with your group to complete this task.

In the table below draw at least four different macroinvertebrates you found in PBC. Label the distinguishing characteristic.(Do not just copy the picture on the key.)

Macroinvertebrate:
Distinguishing Characteristic:
Tolerance to Pollution: / Macroinvertebrate:
Distinguishing Characteristic:
Tolerance to Pollution:
Macroinvertebrate:
Distinguishing Characteristic:
Tolerance to Pollution: / Macroinvertebrate:
Distinguishing Characteristic:
Tolerance to Pollution:
Macroinvertebrate:
Distinguishing Characteristic:
Tolerance to Pollution: / Macroinvertebrate:
Distinguishing Characteristic:
Tolerance to Pollution:

Biotic Index Calculation:

Questions:

1)  Does this score surprise you knowing what you know about Pheasant Branch Creek? Why or why not?

2)  Is this score an accurate assessment of stream quality? How might you strengthen your assessment?

3)  Does any further action need to be taken in response to this index score? If so, describe what you think should be done.

4)  What was your favorite part of this activity? Why?

Biotic Index Direction Sheet

STEP 1: Two people in waders should collect a sample using the technique demonstrated in class. One person is responsible for holding and maneuvering the Dip net and the other person is responsible for helping with the sampling tub. Remember you should do three rounds of sampling (at a different spot each time) before placing the sampling bin on shore.

STEP 2: Place sampling bin on shore in an area where several people can examine it.

STEP 3: Using the spoons, Pasteur pipets and other tools try to catch and isolate different macroinvertebrates in the wells of the ice cube tray.

STEP 4: Make detailed drawings of your isolated macroinvertebrates using your eyes and the hand lens.

STEP 5: Identify your macroinvertebrates using the Identification chart for Rivers and circle each macroinvertebrate on your biotic index calculation sheet.

STEP 6: Perform the biotic index calculation as outlined on the calculation sheet. (Transfer these numbers to your individual worksheet.)

STEP 7: Place the macroinvertebrates collected back in the creek and rinse out your bin and dip net.

STEP 8: Assess the quality of the creek and answer the questions on your worksheet.