SWIMMING AGAINST THE TIDE: EFFORTS TO RECOVER FRESHWATER MUSSELS
FROM THE THREAT OF EXINCTION.

Kurt I. Welke1, Todd Turner2, Roger Gordon2, and Pam Thiel3.  
1Wisconsin Department of Natural Resources, Fitchburg, WI 53711  2U.S. Fish and Wildlife
Service, Genoa National Fish Hatchery, Genoa WI 54632  3U.S. Fish and Wildlife Service,
LaCrosse FRO, Onalaska, WI 54650.

Freshwater Mussels (Unionidae) are recognized as North Americas most seriously imperiled
fauna. Approximately 67% of the 300 recognized species are designated as vulnerable to
extinction or already extinct.  The rate of loss has accelerated rapidly within the last 50 years as
the effects of impoundment, sedimentation, channelization, dredging and water pollution have
manifested themselves acutely and chronically. Currently, the zebra mussel (Dreissena
polymorpha) threatens to eliminate already weakened populations, a fact legally affirmed by the
issuance of a jeopardy opinion on the continued operation and maintenance of the Mississippi
River 9-foot navigation project.  In early 2000, a cooperative effort was initiated by personnel
from the WDNR and USFWS to prevent the extinction of the federally listed Higgins Eye Pearly
Mussel (Lampsilis higginsi).  Juvenile mussels were propagated at the Genoa National Fish
Hatchery using standard mass infection procedures on largemouth bass (Micropterus salmoides)
and walleye (Stizostedion vitreum) host fish.  Culturing of juveniles occurred in 4 differing
treatments to identify factors that contributed to optimal survival and growth. Mussels were
successfully stocked into recipient habitats in summer/fall 2000. The effort will be continued and
expanded in 2001.

Keywords:  mussels, recovery, propagation