Wednesday, May 28, 2008 - 2:15 PM
444

Distribution of dreissenids in great lakes coastal ecosystems: Are wetlands resistant to invasion?

Kristin M. Nelson1, Carl R. Ruetz III1, and Donald G. Uzarski2. (1) Annis Water Resources Institute, Grand Valley State University, 740 West Shoreline Drive, Muskegon, MI 49441, (2) Department of Biology, Central Michigan University, Brooks 156, Mount Pleasant, MI 48859

Invasive Dreissena mussels have become widespread throughout the Great Lakes basin.  However, Great Lakes Coastal Wetlands appear to demonstrate varying levels of resistance to this invasion. To determine if some Great Lakes coastal wetlands are resistant to invasion, artificial substrates were placed in adjacent lake and wetland habitats. Substrates were incubated for 12 weeks at 15 sites in the Great Lakes, including coastal drowned river mouths and open/protected lacustrine wetlands, during summer 2007. Concurrently, an experiment to determine if Dreissena mussels can survive in each wetland type was performed.  We did not find a significant difference (p=0.65) in Dreissena abundance between lacustrine wetlands and adjacent lake habitats. However, Dreissena abundance was significantly lower (p=0.022) in drowned river mouth wetlands than adjacent lake habitats.  We found decreased survival in drowned river mouth wetland versus lake habitats (p<0.001), whereas survival did not vary based on habitat type (p=0.38) in the lacustrine systems.  Drowned river mouth wetlands appear to be resistant to Dreissena mussel invasion while lacustrine wetlands do not display this resistance.  Possible mechanisms for this resistance include differences in organic sediment depth, chemical/physical variables, and water movement between habitat types.


Web Page: Dreissenids, Wetlands

See more of Wetlands
See more of Contributed Sessions

See more of The Nabs 56th Annual Meeting (25-28 May, 2008)