SS3.06 Large Scale Change in Prominent Ecosystems
Date: Wednesday, June 12, 2002
Time: 2:30:00 PM
Location: Lecture Theatre
FahnenstielGL, LMFS/GLERL/NOAA, Muskegon, USA,
Nalepa, T, F, GLERL/NOAA, Ann Arbor, USA,
The impact of zebra mussels on the Great Lakes: Examples from lakes Huron and Michigan
In the 1990s large populations of the zebra mussel, Dreissena polymorpha, became established throughout the upper Great Lakes. We studied the impact of these organisms in two large, but contrasting environments. The first was a large shallow productive bay in Lake Huron, Saginaw Bay, and the second environment was Lake Michigan (mean depth 100 m). In both environments zebra mussels contributed to large changes in phytoplankton biomass, primary productivity, pelagic/benthic coupling,. secondary productivity, and benthic invertebrate biomass. In the shallow bay these changes were larger and more immediate. Overall system primary productivity did not appear to change in the shallow system due to a large increase benthic productivity, but in the deeper system overall productivity did decline as there was no significant increase in benthic productivity (substrate and/or light limitation).