Monday, September 26, 2011

Episode 81 (September 26, 2011): Aquatic Macroinvertebrates and Stream Assessment

Click to listen to episode (2:30).

Please see below (after the transcript and show notes) for links to news and upcoming events.


From the Cumberland Gap to the Atlantic Ocean, this is Virginia Water Radio for the week of September 26, 2011.

This week we feature another series of mystery sounds.  Have a listen for about 45 seconds, and see if you can guess what kind of water investigation these people are doing.  And here’s a hint: How’s the water?  Look below the surface!


If you guessed sampling aquatic life, you’re right!  You’ve been listening to Virginia Master Naturalist students doing a Virginia Save Our Streams assessment of water quality using benthic macroinvertebrates.  That mouthful means organisms that live on the bottom of a stream or lake, are visible without a microscope, and have no backbone.  This includes many kinds of immature insects, but also crayfish, snails, and other animals.  Macroinvertebrate surveys are one type of bioassessment, where the composition of a biological community helps indicate the ecological conditions of a water body.  In contrast to chemical and physical measurements, which provide information on conditions at the time of measurement, bioassessments—whether using invertebrates or other organisms—reveal the impacts of such conditions over a period of time.

For other water sounds and music, and for more Virginia water information, visit our Web site at, or call us at (540) 231-5463.  From the Virginia Water Resources Research Center in Blacksburg, I’m Alan Raflo, thanking you for listening, and wishing you health, wisdom, and good water.

Thanks to the New River Valley Chapter of the Virginia Master Naturalists for help with this week’s sounds, recorded by Karen Reighley during a Master Naturalist field trip at Glen Alton in Giles County, Virginia, on September 17, 2011.

Sources:  More information on aquatic assessment and benthic macroinvertebrates is available in “Bottom-dwellers Tell Stories about the Water Above,” by Sarah Engel in Virginia Water Central Issue #21 (April 2002), online at  The article starts on page 11 in the two-column version and page 12 in two-column version; both are available online); be sure the check out the aquatic invertebrate cartoons by George Wills!  Information about the Virginia Master Naturalist Program is available online at  Information about Virginia Save Our Streams is available online at  Virginia Save Our Streams is a program of the Izaak Walton League of America (

Recent Virginia Water News
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Water Meetings and Other Events
For events related to Virginia's water resources, please visit the Quick Guide to Virginia Water–related Conferences, Workshops, and Other Events, online at  The site includes a list of Virginia government policy and regulatory meetings occurring in the coming week.