221 Assessing the breadth of exotic parasite infections in native benthic communities of the upper Mississippi River

Tuesday, May 19, 2009
Ambassador Ballroom
Gregory J. Sandland , University of Wisconsin-La Crosse, La Crosse, WI
Roger J. Haro , River Studies Center, University of Wisconsin - La Crosse, La Crosse, WI
Benjamin A. Walker , University of Wisconsin-La Crosse, La Crosse, WI
Bithynia tentaculata is an invasive aquatic snail that was introduced into the Great Lakes in the late 1800s.  In 2002, it was discovered in the Upper Mississippi River and since that time it has expanded its range southwards beyond Navigation Pool 11.  In addition to being a threat to native benthos, the snail also harbors 3 exotic parasite species that cause thousands of waterfowl deaths each year.  Unfortunately, the specific factors that dictate the persistence and spread of both the snail and its parasites remain largely unknown. Over the last 8 months, we have utilized a combination of field-based approaches and experimental manipulations to better understand this complex interaction.  Results from this preliminary work show that exotic parasites have the capacity to infect native host species which, in turn, may enhance transmission rates to waterfowl.  In addition, controlled exposure experiments using exotic and native parasites revealed asymmetrical infection patterns among different members of the gastropod community.  The consequences of these findings for both B. tentaculata spread and exotic-parasite transmission will be presented.