It was a very cool Sunday morning for the vertebrates among us, but for the aquatic invertebrates in the stream at McDonald Sports Park, it was actually quite warm. We went to the park with Lesely Carter, an expert in stream sampling of aquatic invertebrate at Environment and Climate Change Canada. She explained that there are things we can learn about streams from sampling benthic (bottom-dwelling) invertebrates (bugs, and other organisms with no spine) that we can’t learn from water sampling alone. And so, we set out to sample the little stream that runs from Muddy Pond to Thomas Lake. Lesley had her hip-waders on and went into the stream. She placed her net in the river and kicked the bottom just upstream of the net. It was hard work to do it for 2 minutes!

She then pulled out the net and brought it ashore. The net had a kind of tube at the end that let out water but caught invertebrates. She emptied the contents of this tube into a tray and voila… tons of squirming bugs and things! From there, everybody got to use foreceps, sticks, hands and trays to sort the creatures into similar-looking groups. Using identifying cards and dichotomous keys Lesley brought, we found we had: mayflies, stoneflies, caddisflies, dobson flies, dragonflies, snails, and worms.

Whether we find certain groups of bugs, and what proportions we find them in, tells us a bit about the health of the river. We found plenty of the invertebrates that can’t handle pollution, so the river was deemed pretty healthy!

Thanks to all the tough, enthusiastic families who came out for the field trip, to Lesley, and to the Community Environmental Monitoring Network, who lent us some of the equipment we used. Here is that great invertebrate key Lesley shared with us. And check out photos from the event in our gallery!