Vernal Pool Adventure - Insect Ecology May 2024

 This week we took a short trip to a vernal pool near the Au Sable Campus. A vernal pool is a standing of water that is only filled during the spring season. Because this pool only is filled during this time period, it means that there are no fish within this water making it a perfect breeding ground for insects. We loaded up a van with some supplies to help us in our search for these aquatic bugs. We brought along nets for scooping along the bottom of the pool while kicking up sediments in hopes of disturbing any nesting or hiding creatures which can then be poured into a tray for observation. Something we had to be careful of while sampling is not to kick up too many sediments into our nets or else water could not drain and we would not be able to identify the found insects. The pool itself is fairly small with not much area to cover and is not very deep, but it is very dark in color and covered with tons of aquatic plants that obscure the view of what is underneath. Once we all entered the water in our waders, we quickly found that navigating the pond would be more difficult that initially assumed. The bottom of the pond is full of decaying plant matter and other sediments that make sinking down in the muck a common occurrence. Once we started scooping water, we began to find many creatures, most of them fairly small in size and hard to see. Once larger creature we found, though not an insect but still cool, was tons of tadpoles that inhabited the area. Once we began taking samples into our floating trays, we could notice many small dark beetle like creatures, little worm insects, and other various small things. After around 20-30 minutes of wading and sampling, a few of us went to shore to begin the sorting process of our findings. We used pipettes to pull up the insects and put them in different ice cube trays. Some of the insects we were able to locate were mosquito larvae, damselflies, flatworms, ghost midges, caddisflies, and other small crustaceans. These insects were large in number and after only a small amount of time looking for them, we probably had hundreds of individuals that could be seen. Many of the creatures were difficult to get separated due to their small size and fast speed, but once we felt we had found a fair amount of these insects we went ahead and got them put into vials of water for transport back to the lab. Once we collected all supplies and made it to the lab, we began to separate all the individuals by species as best as we could. The hope will be to have all the different species killed with alcohol and then later separated amongst all of us in the insect ecology class to be added to our collections. In our class, Isaac actually found some larger diving beetle specimens that will be big enough to pin rather than submerge in the alcohol. I personally did not collect any aquatic insects for my collection because I tend to enjoy larger once that can be pinned, but sadly I was unable to locate any larger bugs myself. This was a great experience using waders and working with the nets to locate insects in a different environment and I plan to go out to different locations around Au Sable and see what other aquatic larvae or insects may be hiding within the waters. Very fun experience and I'm just happy I didn't fall into the water.

Sources:

https://mnfi.anr.msu.edu/abstracts/ecology/Vernal_Pool.pdf

https://www.vernalpool.org/invertebrate-album