Spring 2013 Water Seminar Series - "Effects of the Zebra Mussel Invasion on Aquatic Ecosystems: the Hudson River and Beyond"

Non-native species are moving freely around the world with human commerce, causing large ecological changes and economic damages. I will describe the effects of one such non-native species, the zebra mussel, on the Hudson River ecosystem. Zebra mussels appeared in the Hudson in 1991, and by the end of 1992 outweighed all other consumers in the ecosystem. This enormous population changed nearly every characteristic of the Hudson River ecosystem: plankton fell by 80%, populations of native shellfish and other animals that depended on plankton declined or disappeared, water chemistry and clarity changed, all of which led to large shifts in the growth rates, geographic distribution, and population size of fishes. In recent years, the zebra mussel population and its effects have been changing, suggesting that the initial effects of the invasion are not permanent.