After a relatively quick fall, the mussels at the Minnesota Zoo are settling in for a long winter’s nap. During the summer months, native mussels clean our rivers by removing algae and sediments from up to 10 gallons of water per day! Their movements help to release food from river bottoms for small insects and plants while holding rocks and gravel in place to create habitat for native fish. During the colder months, these ecosystem engineers cuddle up in the river and lake bottoms to retreat from the ice and survive on the nutrients accumulated over the summer. Earlier this month, the Zoo’s mussels – more than 700! – were tagged and measured, which will allow us to document how well individual mussels grow in cold water. In the coming years, we will continue to track their growth in different conditions, helping us to understand how we can improve their care so that they can be placed in the wild by the Minnesota Department of Natural Resources as soon as possible.