LTREB: Developing a Long-term Perspective on the Response of an Aquatic Ecosystem to an Invasive Bivalve

Cary Institute Of Ecosystem Studies, Inc., Millbrook NY

Investigators

Abstract

0075265 Strayer Introductions of exotic species are one of the major ways by which humans affect ecosystems globally. Exotic species have been shown to change the chemical and physical properties of ecosystems, as well as their species composition. Nevertheless, our knowledge of how invasive species interact with ecosystems is still incomplete. An important problem with many studies of invasive species is that they are done soon after the species arrives. The results of such short-term studies may be misleading if the system shows transient dynamics or if the system is driven by factors that vary from year to year, and which interact with the invader. Both of these circumstances are common in real ecosystems. This LTREB project will explore the transient and long-term response of the Hudson River ecosystem to the zebra mussel invasion. This group has been observing the Hudson ecosystem since 1986. Zebra mussels appeared in the Hudson in 1991, and soon caused dramatic changes to the phytoplankton, zooplankton, bacteria, zoobenthos, light quality, nutrients and dissolved oxygen in the river. Over the last few years, evidence has begun to appear that some of the observations made in the early years of the invasion may be transient responses, and may not represent the long-term response of the Hudson River to the zebra mussel invasion. The overall objective of this long-term study is to determine if the interaction between the invasive species and the ecosystem is changing significantly, and if the short-term response of the ecosystem adequately represents its long-term response. This work will help to define the roles of the zebra mussel and other bivalves in aquatic ecosystems, advance our understanding of large river ecosystems, and elucidate the interactions that occur as an invasive species and an ecosystem accommodate one another.