Saturday morning, students from the Program in the Environment (PitE) Club joined over 75 other volunteers and the Huron River Watershed Council to search for stoneflies in the Huron River.
Stoneflies are a type of aquatic insect that are highly intolerant to pollution, meaning they can only live in clean, quality water. Their presence in a stream or river is indicative of its health and quality. When stoneflies are not present in areas of a stream where they could successfully live, it’s a warning sign that the quality of the water has decreased.
The Huron River Watershed Council (HRWC) conducts the Stonefly search to determine the overall health of the Huron River, which requires sending volunteers to various sites along the river and connected creeks and streams.
Despite the cold January temperatures, the Stonefly search is always done in the winter because of the stoneflies’ unique life cycle. Once certain types of stoneflies have matured, they become terrestrial insects, meaning volunteers can’t find them during the April River Roundup, another similar volunteer activity lead by the HRWC. The stoneflies are able to avoid most predators during the winter months while most fish are sluggish.
Volunteers were organized into teams and sent to various sites around southeast Michigan to help with the collection. Lead by two experienced volunteers, the PitE club team went to two locations just a short drive from Ann Arbor, starting at a creek behind Dexter High School.
A make shift “work station” was set up at the side of the creek while the collector, protected by waders and rubber gloves, entered the creek to collect water samples. The volunteers then brought back the samples and sifted through them with netted spoons and tweezers, removing any stoneflies that were present.
The stoneflies were then placed in a jar of alcohol to be preserved and brought back to the HRWC. The volunteers spent about 40 minutes at the first site before travelling to the next one. However, due to icy conditions, the collector was not able to enter Mill Creek, the second site the PitE club visted, in places where stoneflies were accessible. The collector managed to find an area of flowing water, but the places where stoneflies would normally thrive were out of reach under the ice. No stoneflies were collected from the second site, but in this instance weather and lack of appropriate habitat were the main contributors, not poor water quality.