Wisconsin successfully reintroduced endangered spectaclecase mussels into the Chippewa River after decades of research and collaboration.

The Wisconsin DNR released 177 endangered spectaclecase mussels into the Chippewa River, marking the first successful reintroduction of hatchery-reared individuals of the species. Once thought extirpated due to habitat loss, the mussels rely on mooneye and goldeye fish as hosts, a challenge overcome after decades of research. Juveniles were raised in Minnesota and at Genoa National Fish Hatchery before being released into a carefully selected habitat with rock piles and flat stones. The effort involves collaboration between Wisconsin, Minnesota DNRs, and the U.S. Fish and Wildlife Service. Spectaclecase mussels, once widespread across 14 states, are now rare, with Wisconsin hosting 50 native species, 24 of which are endangered. Native mussels improve water quality by filtering pollutants and serve as ecosystem health indicators.