MADISON, Wisconsin (AP) – Biologists discovered a group of rare mussels that may be over 100 years old in the upper reaches of the St. Croix River last summer.
Wisconsin Public Radio reported Wednesday that biologists from the University of Minnesota, the Wisconsin Department of Natural Resources and the National Park Service discovered eight spectacle mussels in the river in August.
Spectacled mussels rely on moon-eyed and gold-eyed fish to serve as hosts for their larvae. But a hydroelectric dam built in 1907 prevented fish from swimming upstream and reaching the mussels in the upper Sainte-Croix. Younger spectacle mussels were found downstream of the dam, but researchers stopped looking for them upstream in 1987. They were surprised to find some still alive in the upper reaches of the river, officials said. of the MNR in a press release.
“Native mussels can live a long time, but these mussels were pushing the limits,” Lisie Kitchel, a DNR biologist who was part of the team that discovered the cluster, said in the press release.
She told WPR the group will likely die, but biologists will continue to monitor them to see how long they live.
MNR officials said in the press release that biologists will try to preserve the genetics of the cluster before it perishes in hopes of increasing the population in upper St. Croix or reintroducing the cluster. moon eye or withers above the dam to encourage breeding.