April O’Neil / news@WHMI.com

The U.S. Fish and Wildlife Service says they’re granting protection to longsolid and round hickorynut mussels, which are essential filters for many Eastern and Midwestern streams. One of those species is local to Michigan waterways.

The two U.S. species of freshwater mussels are now considered threatened, a further sign of trouble for native mollusks that helps cleanse waters by filtering out pollutants as they feed.

The round hickorynut is a medium sided variety of mussel commonly found in Washtenaw County. It has a smooth oval shell with a yellowish brown or greenish hue, according to the MSU Extension’s Michigan Natural Features Inventory. The species inhabits large rivers and lakes, shallow water and swamps, and gravel substrates.

Researchers believe control of the zebra mussel population is critical to preserving native mussels like the hickorynut. Loss of habitat and pollution are big contributors of their decline.

New protections under the Endangered Species Act will raise awareness, encourage conservation partnership, and make funding available for their recovery, according to the Fish and Wildlife Service.

The agency will now work with state wildlife biologists to designate a critical habitat and promote recovery.