Giving Mussels a Lift During Cornwall Flooding Drawdown
A freshwater mussel is held in a hand.
The drawdown of Cornwall Creek Flooding in Cheboygan County is progressing at a rate of about two feet per week ahead of planned renovations to the dam.
As part of the drawdown process, staff with Huron Pines and the Michigan DNR Fisheries Division have been cruising its shallow shorelines by kayak in search of freshwater mussels which may become stranded by falling water levels. By collecting these slow-moving mollusks and relocating them to deeper water, our staff and partners are helping protect a species which serves an important role in the aquatic ecosystem.
Cornwall Creek Flooding is a 161-acre manmade impoundment at the heart of the Pigeon River Country State Forest. Huron Pines is managing the project to lower the flooding by approximately six feet and renovate the dam which is owned by the Michigan DNR Fisheries Division. Some water will remain in the flooding, which is 25 feet at its deepest, over the course of the project.
A freshwater mussel on its way to deeper water.
Freshwater mussels are filter feeders, pulling algae, bacteria and sediments from the water and purifying it in the process. Sensitive to pollution, their presence is an indicator of good water quality and their abundance in Cornwall Creek Flooding helps maintain it that way.
Mussels are also an important food source for wildlife. Piles of their shells—called middens—can be found in places where animals like raccoons and otters crack them open like pistachios to snack on their chewy insides. Middens found alongside weathered tree stumps, the perfect perch for a waterfront meal, are evidence this has been happening at Cornwall.
A shell midden litters the exposed bottom under a stump where wildlife have been feeding on freshwater mussels.
Michigan Natural Features Inventory identifies 43 freshwater mussel species which occur in Michigan. Cornwall Creek Flooding is home to a population of Pyganodon grandis, the giant floater, which can be as big as an open hand and almost two inches thick.
Most of Michigan’s native freshwater mussels are protected under state or federal law. Members of our Water Team are trained in mussel identification which helps us better understand and monitor the health and ecology of Northern Michigan’s waters where we work.
Read more about the Cornwall Creek Flooding project and get updates on the drawdown here.