Powerful Barriers Needed To Stop Exotic Ruffe!
Ann Arbor, MI — Eurasian ruffe are an invasive fish in the upper Great Lakes, and to stop them from spreading to the Mississippi River, researchers tested the possible use of electric or bubble barriers in the canal that links these water bodies.
In the laboratory various levels of electricity and bubbles were tested on ruffe to see what levels would stop or limit the movement of these fish, young and old.
"Eurasian ruffe have been spreading throughout the Great Lakes since their introduction 20 years ago, and could have detrimental effects on native fishes," says Heather Dawson, a researcher at Michigan State University. "We need to stop their spread to the Mississippi River, so we need to find a barrier that works on these fish, but won't affect boat travel."
An electric barrier has been built in the large canal that links the Great Lakes and Mississippi River, and researchers sought to learn what electrical settings for the barrierwould stop ruffe. The larger a fish is, the more electricity it conducts and the greater the jolt it feels. In the researchers' experiments, even strong doses of electricity allowed ruffe to pass through the barrier half of the time. Then, bubble barriers were studied to try stopping younger, smaller fish. Bubble barriers also stopped smaller ruffe only half of the time. The researchers' conclusion was that a stronger barrier, or perhaps the combination of electric and bubble barriers, are needed to stop this invader from spreading!
Original Publication Information
Results of this study "Use of Electric or Bubble Barriers to Limit the Movement of Eurasian Ruffe (Gymnocephalus cernuus)," are reported by Heather A. Dawson, Ulrich G. Reinhardt and Jacqueline F. Savino in the latest issue (Volume 32, No. 1, pp. 40-49) of the Journal of Great Lakes Research, published by the International Association for Great Lakes Research, 2006.
Contacts
For more information about the study, contact Heather Dawson, Michigan State University, East Lansing, MI 48824; dawsonhe@msu.edu; (517) 353-0731.
For information about the Journal of Great Lakes Research, contact Marlene Evans, Editor, National Water Research Institute, 11 Innovation Boulevard, Saskatoon, SK, S7N 3H5, Canada; editor@iaglr.org; (608) 692-1076.
Links
Since 1967, IAGLR has served as the focal point for compiling and disseminating multidisciplinary knowledge on North America's Laurentian Great Lakes and other large lakes of the world and their watersheds. In part, IAGLR communicates this knowledge through publication of the Journal of Great Lakes Research, available to members in print and electronic form. A searchable archive of the journal is available online and includes the abstracts of articles from the journal's inception in 1975 through the most recent issue. In addition, complete articles are available to members who have signed up for an electronic subscription.
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