It is well documented that the introduction of dreissenid bivalves in eutrophic lakes is usually associated with decreases in turbidity and total phosphorus concentrations in the water column, concomitant increases in water clarity, as well as other physical changes to habitat that may have cascading effects on other species in the invaded waterbody. In contrast, there is a paucity of data on the ecological ramifications of the elimination or decline of dreissenids due to pollution, bottom hypoxia, or other mechanisms. Using data collected by the U.S. Environmental Protection Agency Great Lakes National Program Office's Long-Term Biology and Water Quality Monitoring Programs, we analyzed the impacts of the hypoxia-induced declines in Dreissena densities in the central basin of Lake Erie on major water chemistry and physical parameters. Our analysis revealed that the decline in Dreissena density in the central basin was concomitant with a decrease in spring dissolved silica concentrations and an increase in total phosphorus and near bottom turbidity not seen in the western or eastern basins. In contrast, opposite patterns in water quality were observed in the eastern basin which was characterized by a high and relatively stable Dreissena population. We are the first to report on observations suggesting that dreissenid-related shifts in water quality may be reversible by documenting that the sharp decline of Dreissena in the central basin of Lake Erie was concomitant with a shift from clear to turbid water.
Bibliographical noteFunding Information:
This research was supported by a Great Lakes Restoration Initiative cooperative agreement from the U.S. Geological Survey , Department of the Interior, under USGS Agreement No. G14AC000263 , “Lake Erie and Lake Michigan Benthos: Cooperative Science and Monitoring Initiative”. This publication was also supported by an agreement with Cornell University, Department of Natural Resources under Prime Agreement Award GL 00E01184 from the U.S. EPA “Great Lakes Long-Term Biological Monitoring of Zooplankton, Benthos, and Chlorophyll a”. We appreciate the assistance of the Captain and crew of the U.S. EPA R/V Lake Guardian , and Susan Daniel, Joshua Fisher, Wendy Paterson, Brianne Tulumello, and Keith Pawlowski (SUNY Buffalo State, Great Lakes Center) for help with sample collection and sorting. The views and conclusions presented in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either express or implied, of the U.S. Government.
© 2018 International Association for Great Lakes Research.
- Dreissena rostriformis bugensis
- Ecosystem impacts
- Lake Erie
- Long-term changes