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The Verdict

 

Judge Macro

The case was sent to Judge Macro's court. A verdict will be rendered.

What will it be?

Guilty or Not Guilty?

Clean or Polluted?

Healthy or Unhealthy?

The U.S. Environmental Protection Agency describes macroinvertebrates as good evidence of pollution because they

  • live in the water for all or most of their life
  • stay in areas where they are likely to survive
  • are easy to collect
  • are different in their tolerance to the amount and types of pollution
  • are easy to identify
  • often live for more than one year
  • do not move around very much
  • are integrators of environmental condition

MarekIt is not always easy to decide if the water is polluted or clean. The quality of the habitat, the water chemistry, and the integrity of the macroinvertebrates have to be considered when deciding if the water is clean or polluted.

Let's make it simple. If there are MANY, MANY, MANY "clean water" insects, you can feel pretty good about the quality of your stream, river, lake, pond, or water body! If you find a variety of ALL of the groups of macroinvertebrates you know the water is probably not polluted.

After four visits we have concluded that the water quality of Caffee Creek is good. In all we found 89 macroinvertebrates, mostly in the sensitive category. On each visit we stayed in the general area of our "headquarters". Some possible reasons we did not find many macroinvertebrates in the first three visits are:

1. We picked a spot that had too much sediment. It had filled in the areas that macroinvertebrates would live.

2. Some resources said the best time to monitor the water is March and April and some sources said the best time to find them is in December, January, February. We found the most macroinvertebrates in the spring months.

3. On our fourth visit we moved 10 feet upstream where the water was moving more swiftly with many more rocks.

There are advantages to combining different methods of water monitoring. Chemical testing provides part of the information such as which pollutants are trapped in the water.

Macroinvertebrates provide another part of the information. They live in the same area for a long time. Some of them live up to 4 years. This is why they tell a lot about the water quality over a longer period of time.

 

How can the information from macroinvertebrate testing be used?
  • Macroinvertebrates can be used to educate people about their waterway and the importance of keeping it clean.
  • Monitoring macroinvertebrates gives a starting point for comparing results over a period of time. It also gives a starting point for monitoring the health of a waterway upstream and downstream from the original site.
  • If there is pollution on a waterway and you find a way to stop it, use macroinvertebrate monitoring to see if the health of the waterway improves.
  • Macroinvertebrate monitoring can show if the water is healthy enough for fishing, boating, swimming, or other activities on the waterway.
  • Use macroinvertebrate monitoring to see if the waterway's health improves or gets worse over a long period of time.

Another CSI case has ended and the verdict is CLEAN!

We love our detective jobs!

 

creek creek crossing

The picture on the left is our monitoring site. The picture on the right is upstream from the monitoring site two days after it rained. Look at the difference in the water clarity. Why do you think the water looks different upstream?

Be sure to visit the other pages in our website.

 

Magnify Your Mind

1. If there are many stoneflies in the water it is probably

polluted.

not polluted

2. Macroinvertebrates are good indicators of water quality over a long period of time because they

move from place to place.

stay in the same place for a long time.

 

Learn More

Water Quality

Water Science for Schools

Citations

Cheasapeake Bay Program. Water Quality. Retrieved April 2007 from http://www.chesapeakebay.net/wquality.htm .

Earth Force. Benthic Monitoring Guide. Retrieved October 2006 from http://www.green.org/files.cgi/234_Benthic_Monitoring_Guide.html .

Evaluate a Stream. Retrieved March 2007 from http://www.saveourstream.org/evaluateastream.htm .

Fish and Aquatic Life: Aquatic Macroinvertebrates. Retrieved October 2006 from http://www.krisweb.com/aqualife/insect.htm .

Haddock, R. (2007, February 20 - April 2 ). Phone interviews and emails on benthic macroinvertebrates, water temperature, habitat quality, macroinvertebrate populations, identification of macroinvertebrates, condition of Caffee Creek.

Izaak Walton League of America. Biological Stream Monitoring. Retrieved October 2006 from http://www.iwla.org/index.php?id=118 .

Kristofik, E. (2007, September - April ). Personal interviews and emails on benthic macroinvertebrate monitoring, choosing a testing site, water pollution, identification of macroinvertebrates, equipment, refuge management, habitat quality.

Macroinvertebrate Monitoring. Retrieved November 2006 from http://depts.washington.edu/natmap/water/3monmac.html .

Maryland Department of Natural Resources. Freshwater Benthic Macroinvertebrates. Retrieved December 2007 from http://www.dnr.state.md.us/streams/pubs/freshwater.html .

Stream Biological Monitoring. Retrieved October 2006 from http://www.ecy.wa.gov/programs/eap/fw_benth/index.html .

U.S. Environmental Protection Agency. Aquatic Biodiversity. Retrieved October 2006 from http://www.epa.gov/bioindicators/aquatic/index.html

U.S. Environmental Protection Agency. Invertebrates as Indicators. Retrieved December 2007 from http://www.epa.gov/bioindicators/html/invertebrate.html .

U.S. Environmental Protection Agency. Macroinvertebrates in Our Waters. Retrieved December 2007 from http://www.epa.gov/bioindicators/html/benthosclean.html .

USGS. Water Science for Schools. Retrieved April 2007 from http://ga.water.usgs.gov/edu/waterquality.html .

Water Watch Australia. Retrieved January 2007 from http://www.waterwatch.org.au/publications/module3/monitoring.html#strength .

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