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Stream Critters

Saturday, April 19, 2008
A group of fourteen adults and children explored the Sligo Creek waters just below University Boulevard looking for stream critters with leader Adam Griggs, an aquatic biologist with the Interstate Commission on the Potomac River Basin. Our site was at the first parking lot downstream from University Boulevard. We were joined by photographer Charles Shoemaker of the Gazette Newspapers, which ran a front page photo from the outing.

Adam immediately noticed the considerable amount of algae floating in the stream and said it was more appropriate for a barnyard pond than a stream. This level of algae in early spring indicated an excess of nitrogen, probably arriving directly from nitrogen pollution in the atmosphere through rainfall.

We used a miner's sieve bucket to filter small critters from the water.

The kids then eagerly sorted them into the "ice-cube tray" and


enjoyed close-up looks through Mike Smith's field microscope.

Photos by Michael Wilpers
Text by Michael Wilpers from Laura Mol's notes