Arts and Crafts and Procedures
(Continued)
A “How To” Guide on Collecting BMI
Objective:
Materials:
Procedure:
1.Each group will collect BMI from their section of stream that they previously used for water sample collection and physical data collection.
2.Approach the sampling location from downstream and sample the site farthest down stream first. Do not walk in the stream unless it is to specifically conduct the survey because walking in the stream unnecessarily might dislodge BMI and alter sampling results.
3.Make sure the kick net is clean before collecting BMI. Then select a one meter square riffle for sampling.
4.Select two members of the group to be the net holders, and then position the net holders at the downstream end of the sampling area.
5.Place large rocks from the area on the bottom of the net to secure it to the stream bed, making sure no BMI escaped under the net.
6.Once the rocks are in place, hold the net at a forty-five degree angle to the water’s surface. Make sure no water is flowing over the net so BMI don’t escape over the top of the net either.
7.Assign another member of the group to be the kicker. Position the kicker upstream of the one meter sampling area, and have said member dislodge the organisms by kicking the bottom of the stream, moving downstream towards the net as the member kicks. By kicking the stream bed, not only was the soil being dislodged, but so was the BMI.
8.The kicker should kick for about one minute, making sure to disturb the first several centimeters of the stream bed, not just the top.
9.Once the soil plume travels downstream past the net, pick up the rocks used to anchor the net and place them in buckets filled with water.
10.Remove the net without allowing BMI to wash away. Have one member grab the top of the net handles and another grab the bottoms, then remove it from the stream with a forward scooping motion.
11.Remove all BMI and debris off the net using plastic spoons, and place the BMI in water filled, white trays. While the BMI is being removed, wet down the net with stream water to help insure that the BMI will survive the sampling.
12.After the net is cleared, move onto the rocks. Carefully remove BMI clinging to the rocks and place them in the white trays as well.
13.Once all BMI is removed from the rocks, carefully return the rocks to the stream from where they were removed.
14.While sorting through the BMI, keep the pans filled with stream water as well as the petri dishes.
15.When identifying the BMI, use a dichotomous key on macro invertebrates. Keep record of what kind and how many BMI are collected.
16.Return the BMI to the stream as soon as possible.
17.Once all the BMI are back in the stream, clean the equipment used and place them in the sun to dry.
18.Proceed to share the data with the other groups. Once all the data is collected, find the stream quality rating. Check with the other groups to confirm the answer is correct.
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