What’s in your backyard?
Take a little trip back in time with me, please: It’s mid-February. The temperature has been below freezing for weeks, and snow covers the landscape. I take my Biology 122 students at Waubonsee Community College out to collect samples from Blackberry Creek. Amid the grumbling about the cold, students remark at how anything could still be alive in these conditions.
But, we are looking at this from a human perspective. We traipse out to the far north edge of the Sugar Grove Campus, crack through the ice in Blackberry Creek, and an insulated, living world is found beneath the surface. Just because we need parkas, hats, and gloves, doesn’t mean the invertebrates do. They can survive out here year-round.
It’s not just their survival in extreme temperatures that is remarkable, but their ability to survive the pollutants that wash in from agricultural fields, from salt-covered winter roads in the suburbs, and from urban development. This is a unique body of water, and a unique set of organisms that inhabit it. And we probably take it for granted.
If you live north of the college, you cross Blackberry Creek on Route 47 every day on your commute. It snakes through the communities of Elburn, Kaneville, Sugar Grove, Aurora, Montgomery, and Yorkville. It dictates our watershed—the entire region draining into this body of water. It is an amazing ecosystem.
So, underneath the surface, what lies inside, and what story do they tell? Dip in an aquatic net, and you will find what look like tiny shrimp scuttling around. They are a tiny crustacean that flourish in water with few fish predators. They can withstand some of the most polluted water conditions. You might also see a tiny, red worm. This is called a bloodworm, and is a larva of a fly called a midge, which you probably walk through clouds of on a walk at dusk by your local retention pond. Lots of bloodworms - and little else - is also a sign of polluted water.
You have a good chance of also coming across two jewels—a water scorpion, and a dragonfly larva. A water scorpion looks like a three-inch stick insect that has lost its way. What you will also notice is its long front arms, which are perfect for a water predator. As for the dragonfly - did you know that their offspring live in the water? This is a brilliant evolutionary strategy, keeping parents and offspring from competing for precious resources. Like the adult, these babies are agile hunters, trapping prey in their scoop-like mandibles.
What story does this net full of living things from your backyard creek tell? Well, more predators means a healthy aquatic ecosystem, because if the ecosystem can support a predator, it is healthy enough to provide for the prey items it feeds on. But, an abundance of organisms that thrive in stagnant water, feeding on decaying plant matter isn’t a good sign. In Blackberry Creek, we have a mixture of both, with water quality somewhere between pristine and not.
So, next time you are walking near Blackberry Creek, think about what lies under the surface, and how they can dictate whether you should take a sip, or pass.
Dani DuCharme is an associate professor of Biology at Waubonsee Community College, and was named this year’s Outstanding Faculty Member.