Summary #
Proper collection technique is critical for reliable biological monitoring data. This page covers the major methods for collecting macroinvertebrate samples, including kick sampling, surber sampling, and other approaches, with guidance on when to use each method.
The four most common means of collecting benthic organisms are: rock washes, kick nets, sediment drags, and leaf packs. It is a good idea to use a combination of these methods to obtain an accurate portrait of the macro invertebrate population. One important thing to remember before doing any data collection is to start downstream first! This prevents contamination of the next sample site by any dirt, sediment or organisms that are stirred up from the first sampling. It is also a good idea to repeat each sampling method 2 to 3 times at each site to ensure an adequate sample is obtained.
Rock washing is by far the simplest method to explain, but can be difficult to do correctly. Be sure to have some basins available to wash the rocks in as well as sample bags if the samples will be taken to a lab for analysis. Try to choose 3 -4 dinner plate sized rocks from a riffle area. Fill the bottom of the basin with stream water and thoroughly scrub each rock, carefully setting them aside when done. Then proceed to find and identify your critters or transfer the water and
critters to bags to return to the lab. If you are taking the samples to a lab, be sure to have everything clearly labeled and identified. DO NOT MIX SAMPLES!
Kick nets are relatively easy to do, but are best done with 2 people. One person holds a D-frame net (so named because the opening is shaped like a D) against the bottom of the stream in a riffle area while the other person stands in front of the net and kicks the rocks in a approximately a 2 square foot area in front of the net for 2 minutes. D-frames have a fine mesh that allows water to travel through while trapping macro invertebrates. The nets can then be rinsed into basins and counted or rinsed into bags and taken to the lab. Be sure to have filters available to sift out sediment, but retain the macro invertebrates.
Sediment drags are similar to kick nets. It is possible to use a d-frame net for this as well. It this procedure, someone scoops into the sediment on the bottom of the stream and rinses it into a basin or bag as before.
Leaf packs are very easy to use, but require much more time. Prepare leaf packs by filling screen mesh bags with leaves, try to use the same kinds as the trees surrounding your stream. Make sure the mesh is large enough for the macros to climb in. Weight each bag with a rock and attach 3 or 4 to a brick or other weight. Place 3 to 4 bricks in various locations at each sample site. Allow the bricks to remain for about a month before collecting them. When collecting them be sure to look carefully, bricks are often moved by strong currents. Bag the leaf packs and take them back to the lab to count and identify the macro invertebrates.
Do not be surprised if the organisms you gather appear different from the adult, this is normal in insect development. Some of the macros go through incomplete metamorphosis so the nymph grows in size, but changes little in appearance. Others undergo complete metamorphosis, in which the larva looks nothing like the developed adult. At times even separate stages in the development of either type of insect can appear quite different. If there are any questions about the identity of a captured microorganism, be sure to make use of the available help from the conservation district or accessible qualified macro inverterbrate identifier.
Be sure to return most of your samples to the stream to prevent population depletion, questionable, interesting or required samples can be removed and kept for further reference.
Macroinvertebrates: all messed up see pdfs
The next group is http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG2.htm moderately sensitive or (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG2.htm)g (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG2.htm)anisms (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG2.htm). (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG2.htm)
Hi (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroGuide.htm)g (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroGuide.htm)h Sensitivity (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroGuide.htm) http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG2.htm Moderate Sensitivity (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG2.htm) http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG3.htm Low Sensitivity (http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG3.htm)
For general information and descriptions of macro invertebrates view or download http://amrclearinghouse.org/Sub/WATERmonitoring/MacrosBack.pdf What are Macros? (http://amrclearinghouse.org/Sub/WATERmonitoring/MacrosBack.pdf)
Identification and classification manuals are available. For a listing of various sources please go to http://amrclearinghouse.org/Sub/WATERmonitoring/Resources.htm Resources (http://amrclearinghouse.org/Sub/WATERmonitoring/Resources.htm).
Sources/Links (as provided in the source text):
- http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG2.htm
- http://amrclearinghouse.org/Sub/WATERmonitoring/MacroGuide.htm
- http://amrclearinghouse.org/Sub/WATERmonitoring/MacroG3.htm
- http://amrclearinghouse.org/Sub/WATERmonitoring/MacrosBack.pdf
- http://amrclearinghouse.org/Sub/WATERmonitoring/Resources.htm
Related Pages #
- Developing a Monitoring Plan
- Water Quality — What biological monitoring tells us
- Macroinvertebrate Guide — Identifying stream organisms
Source and Last Reviewed #
Source: AMR Clearinghouse (amrclearinghouse.org). Migrated to AML-Connect. Last Reviewed: 2026-03-13.
[Admin note: Some external links in this article may be outdated. Verify before relying on them. Flag dead links for removal or replacement.]
Tags: monitoring, sampling, practitioner
