To return to the Midwest Fish & Wildlife Conference website, go to http://www.midwestfw.org/ The following schedule and room names are subject to change (as of February 1, 2017). Please check back for updates. 

Presenters for technical presentations are either the primary author (the first name listed in the abstract), or are indicated with an asterisk next to their name. 

Please note:
 the conference schedule is hosted by Sched.org which allows you to search within the schedule, and filter the schedule to show sessions only occurring on a certain date or within a track. You can also build your own schedule by creating a free account with Sched.org by selecting "SIGN UP" in the top right corner. 
Back To Schedule
Tuesday, February 7 • 1:40pm - 2:00pm
Symposia Session - S8: Fate of Freshwater Mussels. Twenty-six Years of Change in the Hudson River’s Bivalve Populations

Sign up or log in to save this to your schedule, view media, leave feedback and see who's attending!

AUTHORS: David L. Strayer, Heather M. Malcom - Cary Institute of Ecosystem Studies

ABSTRACT: It is well known that dreissenid mussels kill unionid mussels by overgrowing them, resulting in rapid (4-7 years) extirpation of unionids from many lakes and rivers in North America. Our 26-year study of the freshwater tidal Hudson River shows that other kinds of interactions between these bivalves may be important as well, and that unionids may persist for decades. Three species of unionids (Elliptio complanata, Anodonta implicata, Leptodea ochracea) were abundant in the Hudson before the zebra mussel invasion, each with 10s to 100s of millions of animals in the river. After 1992, all three unionids suffered steep declines in recruitment, adult survival, body condition, and population size. However, exploitative competition for food, not fouling, appears to be the primary mechanism behind these declines. Around the year 2000, the body size (but not the number) of dreissenids in the Hudson fell in response to large increases in dreissenid mortality from blue crab predation and other causes. At the same time, unionid condition, recruitment, and adult survival all rose substantially, suggesting that bivalve body size may affect the strength of competition between unionids and dreissenids. Despite very large year-classes of juvenile unionids since 2005, populations are not recovering because these juveniles are experiencing very high mortality from a crushing predator. This suggests the importance of apparent competition from a shared predator, the blue crab. The net effect of these complex interactions in the Hudson apparently will lead eventually to extirpation of the unionid community, albeit over >25 years.

Tuesday February 7, 2017 1:40pm - 2:00pm CST
Grand Ballroom A

Attendees (7)