MADISON, WI (WTAQ) - One of the most worrisome invasive species in the Upper Midwest – the zebra mussel – appears to be vanishing from the St. Croix River.

It’s been a problem for years on the river, which hugs the Wisconsin-Minnesota border in the northwest part of the Badger State.

Minnesota has been fighting zebra mussels for more than a decade, and experts now say it has virtually disappeared at 8 monitoring spots on the St. Croix.

Experts believe the river’s turbulent water may have flushed the mussels out. They also say that common carp have apparently been feasting on them.