Do you know what a water penny, a midge larva, and a dragonfly nymph have in common? They are all organisms that depend on our local streams and rivers for part or all of their life cycle. You may have heard the term “canary in the coal mine,” a phrase referring to the quality of the air inside a mine; these water organisms serve the same function for our water environments as the canary did for the coal mine. Aquatic biologists refer to these organisms as macroinvertebrates, meaning they are large enough to see with the unaided eye and they do not have an internal skeleton of cartilage or bone.
If you are interested in learning about aquatic life in our local streams, join us at Ruffner Park in Galena on July 11 for Family Creeking Night. This free event is open to all, so wear your old shoes (closed toe only please) and clothes that can get wet for a wade into Big Walnut Creek. A short presentation and all of the equipment for discovering what awaits us on top of (and under the water) will be provided by the Delaware Soil and Water Conservation District (SWCD).
What can these water creatures tell us? Because these organisms are fairly restricted in their movements, they cannot escape significant changes that may occur in the river or stream. Some are very sensitive to changes, some are not, and many fall in between. Identifying the diversity of creatures, the numbers of each, and categorizing their sensitivity, enables us to understand habitat quality. A stream with plenty of water pennies, mayflies, and stonefly nymphs, and riffle beetles signifies a higher quality stream over one with a high number of very stress-tolerant aquatic worms, leeches and midge larvae. Crayfish, dragonfly and damselfly nymphs, and clams can usually exist in a wider range of conditions from pristine to moderate levels of stress.
What is a stressor for a freshwater invertebrate? Manmade and natural factors can influence the quality of our streams and rivers. Erosion from a construction site, livestock in the stream, flooding, debris from logging, discharges of pollutants such as chemicals, failing home sewage treatment systems, and the introduction of invasive species are some of the causes that can affect the health of a stream.
Family Creeking Night will give participants the opportunity to discover what’s in the fascinating world of water. Ruffner Park is located at 183 Harrison St. in Galena, and the evening program will begin at 6:30 p.m. Reservations are requested, so call by July 10 at 740-368-1921. Rain date is July 25.
For information about Delaware SWCD’s 2019 programs, visit soilandwater.co.delaware.oh.us. You can also find us on Facebook and Instagram.
Bonnie Dailey is deputy director of the Delaware Soil & Water Conservation District. For information, go to www.soilandwater.co.delaware.oh.us.