Non-native species have large ecological effects, cause enormous economic damage, and are one of the most important and least well controlled of human impacts on the world?s ecosystems. The long-term effects of species invasions, which may differ considerably from short-term effects, are still poorly understood. Soon after zebra mussels invaded the Hudson River over 17 years ago, they had large impacts on nearly every aspect of the ecosystem. Recently, the zebra mussel population and its effects have begun to change: survival rates of zebra mussels have fallen by a factor of 100, and some, but not all, parts of the ecosystem have recovered toward pre-invasion conditions. This award continues the investigators' long-term study of zebra mussel invasion by quantifying the zebra mussel population and its effects on water chemistry, water clarity, and populations of phytoplankton, zooplankton, bacteria, and native pearly mussels in the Hudson River. Results will lead to a better understanding of the zebra mussel (one of the world's most important invaders), and also provide one of very few detailed studies of the long-term effects of an invader.
Results from this research will be of significant value to managers who oversee with the Hudson River and who confront wide-ranging effects of non-native species. To reach beyond the scientific community, the researchers will disseminate their findings by posting data on open websites; continuing highly successful programs for middle- and high school students; and continuing a very active program of outreach through public lectures, seminars, training workshops, and newspaper articles.