Mike Hoff from Fisheries Regional Office studies a Higgins eye before releasing it into the Mississippi River.

Tony Sullins from the Twin Cities Field Office with a handful of Higgins eye ready for the river.

U.S. Fish and Wildlife Service biologists worked alongside Minnesota, Wisconsin, Iowa and Illinois partners, and Federal Corps of Engineers and National Park Service biologists to help bring a species back from the brink this past month, with the release of more than 6500 2 and 3 year old Higgins Eye Pearly mussels.  The Higgins Eye has been on the Federal Endangered Species list since the early 1970s, about the time the Endangered Species Act was established by Congress, and the list was formulated.  The mussel, although never common in the Upper Mississippi River Basin, was dealt a devastating blow with the introduction of the zebra mussel into the Upper Mississippi River basin in the early 1990’s.  This aquatic invasive species typically uses native mussels as substrate to attach and live on, reducing the native mussel’s ability to breathe, feed, and reproduce.  Large historic mussel beds were literally wiped out when population explosions of zebra mussels covered them in layers of over 12 inches deep in some reaches of the Upper Mississippi River.  This led to biologists from around the basin to establish a mussel coordination team to search for answers on how to reduce the threat of extinction to the Higgins Eye, and subsequently other species of mussels as a side benefit.  A major tool in the Recovery of the Higgins Eye is mussel propagation.  It was found that host fish placed in cages over suitable habitat results in good mussel production and survival and fish species such as bass and walleye historically used in propagation programs at the Genoa (WI) National Fish Hatchery serve as good fish hosts for the Higgins Eye Pearlymussel to be able to complete their reproductive cycle.  Through these cage culture efforts, over 6800 2 and 3 year old mussels averaging over 3 inches in size were release from cages into suitable mussel beds with little or no zebra mussel colonization in the Wisconsin, Rock, and Mississippi River.  Propagation efforts have allowed for the production and release of over 35,000 sub-adult mussels in the past 2 years.  Some of these mussels are now actively reproducing in their new homes, completing the loop of Recovery for hopefully generations to come.