Link to USGS home page.
Upper Midwest Environmental Sciences Center

Finding the Exotic Faucet Snail (Bithynia tentaculata): Investigation of Waterbird Die-Offs on the Upper Mississippi River National Wildlife and Fish Refuge

Open-File Report 2007-1065

By Jennifer S. Sauer, Rebecca A. Cole, and James M. Nissen

This report is available below as a 6-page PDF for viewing and printing.


Beginning in 2002, there have been major waterbird die-offs every spring and fall in Lake Onalaska (Navigation Pool 7 of the Upper Mississippi River) located near La Crosse, Wisconsin. This area is part of the Upper Mississippi River National Wildlife and Fish Refuge (UMR Refuge) and lies within the Mississippi Flyway, through which an estimated 40 percent of the continent's waterfowl migrate. Through the 2006 spring migration, total mortality on the UMR Refuge was estimated at 22,000 to 26,000 birds, primarily American coots (Fulica americana) and lesser scaup (Aythya affinis). Two trematodes (Sphaeridiotrema globulus and Cyathocotyle bushiensis) that use the exotic faucet snail (Bithynia tentaculata) as an intermediate host were found to infect and kill the waterbirds. The faucet snail was introduced into the United States from Europe in the late 1800s. Because Lake Onalaska is a major spring and fall stop-over area for waterfowl in the Mississippi Flyway, concerns were raised that the snail and trematodes may be spreading to other waterfowl stop-over areas on the river. Exploratory sampling for faucet snails was conducted in 2005 and 2006 in navigation Pools 49 (excluding Pool 5a which is located between Pools 5 and 6), 11, and 13. Infected snails were found in all the sampled pools except Pool 6. To our knowledge, these are the first records of faucet snails and associated trematodes beyond those found in Pool 7, Lake Onalaska. Waterbird die-offs are becoming a UMR Refuge-wide problem. Information obtained through research and monitoring, including the identification of the origin of infections in snails and birds and the role various environmental factors have on this process, should help guide managers to develop effective mitigation and control measures.


This document is available in Portable Document Format (PDF)

To view and print report you will need to use Adobe Acrobat Reader (available as freeware)

Users with visual disabilities can visit Online conversion tools for Adobe PDF documents web page

REPORT (1.6 MB) - 6 pages (8.5" by 11" paper)

Suggested Citation:

Sauer, J.S., Cole, R.A., and Nissen, J.M., 2007, Finding the exotic faucet snail (Bithynia tentaculata): Investigation of waterbird die-offs on the Upper Mississippi River National Wildlife and Fish Refuge: U.S. Geological Survey Open-File Report 20071065, 3 p.

For more information about activities of the Upper Midwest Environmental Sciences Center, see the UMESC home page.

U.S. Department of the Interior, U.S. Geological Survey
Persistent URL:
Page Contact Information: USGS Publishing Network
Last modified: Wednesday, Wednesday, 07-Dec-2016 20:16:05 EST
FirstGov button Take Pride in America button