We’ve all been there! Between mosquitoes at a backyard barbecue, bees out on the boat, and ants at a picnic – it’s easy to see where the term “don’t bug me!” comes from. However, not all bugs are a nuisance. As a matter of fact, they are a prime example of Mother Nature at work. When it comes to water, aquatic macroinvertebrates – organisms that can be seen with the naked eye, but lack a backbone – include crawfish, clams, snails, worms and insects in the larvae stage. While we may want to keep a fly swatter at the ready inside our homes, these bugs in the water actually signify whether or not a water source is healthy and thriving.
Aquatic macroinvertebrates inhabit all types of running water – from a smaller body of water like a babbling brook or swift-moving stream to a larger water source like the Chattahoochee or Yellow River. They can often be found attached to submerged rocks, logs, and vegetation. According to the Environmental Protection Agency (EPA), some of the reasons these “bugs” in the water serve as a great indicator of stream quality include:
- They are affected by the physical, chemical, and biological conditions of the stream.
- They can’t escape pollution and show the effects of short- and long term pollution events.
- They may show the cumulative impacts of pollution.
- They may show the impacts from habitat loss not detected by traditional water quality assessments.
- They are a critical part of the stream’s food web.
- Some are very intolerant of pollution.
- They are relatively easy to sample and identify.
One specific example the EPA points to relates to stonefly nymphs. These aquatic insects are very sensitive to most pollutants and cannot survive if oxygen levels in the creek or stream fall below a certain point. Therefore, if a biosurvey – which is a scientific study of organisms to assess the condition of an ecological resource – of a stream that typically supports stoneflies shows that none are present, this may indicate that oxygen levels in the water have fallen to a point where stoneflies are unable to reproduce or an event has killed their larvae outright. Some causes of the lower levels of oxygen may be that the stream flows too sluggishly (which may be because of drought or an obstruction downstream) or there are too many pollutants in the water. Monitoring for water quality conditions such as the amount of gaseous oxygen (O2) dissolved in the water, temperature, nutrients, and pH helps identify which pollutants are responsible for impacts to a stream.
In addition to supporting flora and fauna in the area, a clean stream is a great source of beauty, recreation and community pride. Equally important, it is also a “link in the chain” that feeds into larger bodies of water from which we draw our drinking water. Both water quality monitoring and biological assessments (to check for macroinverterbrates and chronicle signs of animals in and around the water) are vital components of the success of Gwinnett’s Adopt A Stream program. We encourage YOU to consider going on a bug hunt this summer! You and your family/co-workers/group could serve as official “keepers” of a portion of a creek or stream by periodically monitoring its condition with supplies, training, and certifications in chemical, bacterial and macroinvertebrate testing provided by Gwinnett Clean & Beautiful and the Gwinnett County Department of Water Resources. After all, each stream has an important role to play in the overall health and beauty of this community we all share, so it’s important we each do our part to protect it – for our enjoyment, as well as the enjoyment of our children and future generations. To learn more about macroinvertebrates and the Adopt A Stream program, fill out our convenient online contact form or call 770-822-5187 and ask to speak with GCB Program Manager, Sumner Gann.
