Benthic Macroinvertebrate Sampling Protocol
1. Locate a safe sampling site within a riffle in a wadable stream.
2. Using a kick net, disturb the substrate in the area upstream of the net for about 2 minutes.
Use arm's length as a guideline for area upstream of net to disturb.
3. Empty sample ( a "kick") into a bucket. Repeat
until 3 kicks are collected, each from a different location in the riffle.
Samples should all be pooled in the bucket (a "replicate").
6. Add water to ice cube tray compartments. Separate similar critters from the white picking tray into ice cube compartments using taxonomic resources as ID references. Sort all organisms in your white picking tray, not just those that are obvious.
7. Continue to subsample the bucket (mix well each time) until at least 100 organisms have been counted (if you like, you're welcome to count more!)
8. If about 100 critters have been counted before emptying the bucket, examine the "leftovers" for any obvious organisms that escaped sampling, especially those that are not already represented in your count. Include these in the final count. Sample additional locations in the riffle if more organisms are needed(collect additional "replicates").
9. Count and record the number of individuals from
each taxonomic group on the back of this sheet. A completed data sheet
should include total numbers of individuals counted in each taxonomic
group (i.e. 13 stoneflies, 7 scuds, 3 crayfish, etc.). Calculate the Index
Score to assess the general health of the stream.