Many insects start their life cycle in the water, as aquatic larvae. I love exploring their world - seeking them out under the rocks and in the current of fast-moving "riffles" in the Black River.
For the past 3 years, I've been developing a study plan to take a closer look at what sorts of creatures live even deeper, below the bed of the river. It's called the hyporheic zone, and the organisms that live there are microscopic. They exist in the "porewater," the water in-between grains of sediment below the gravel and pebbles at the bottom of the river. Life here is slow-paced, with no real current to speak of, just the steady seep of groundwater feeding into the river from the land.
There is a stretch of the Black River that is potentially being impacted by the presence of PCBs leftover from one of the many gear-shaping factories that once put Springfield, Vermont on the world map, a factory that has been closed and the groundwater monitored for decades.
In partnership with the Southern Windsor County Regional Planning Commission, BRAT will be collecting samples of these tiny creatures (called "meiofauna") over the next few years, to gather data on the populations and see what we can learn about the condition of the water down there.
To get a sense of what is living in the hyporheic zone ("HZ"), we will bury 4 colonization tubes in the sediment: two above the contamination site, and two more about 100-200 feet downstream from the contamination site.
That's a fine-mesh screen tube inside the perforated pipes (which my 16-year-old daughter helped me drill tonight on the front porch). The caps at both ends are vented and I used marine caulk to seal more mesh into the caps. This way, only the tiny meiofaunal creatures can get in, not their larger predators.
We will fill the tubes with "native sediment" that we find when we bury them, and possibly rubber-band or zip-tie the top cap on; we'll flag each tube so we can find it again in six weeks by sticking a construction marker into the sediment and tying a strip of flagging tape to the top cap.
Six weeks later, we'll dig them out, empty the contents of each tube into a numbered plastic pickle jar, and return home to explore our "catch."
The partners for this project are diverse and exciting!
~ Erica Smith of the Taiga Chapter of the Society for Freshwater Science
~ Patty Collins, teacher at Reading Elementary School
~ Chris Fishel, aquatic entomologist with Watershed Assessment Associates
~ Corrina Parnapy, aquatic biologist and environmental educator & writer
~ Jim Kellogg, aquatic biologist with the State of Vermont
~ the staff at the Bug Scope with Beckman Institute, housed at U of Illinois