Lake trout swim deep in Lake Mistassini
Ann Arbor, MI — At least two kinds of lake trout swim in the waters of Lake Mistassini, Quebec. One kind is caught in the cool shallow waters, and the second is found in the cold, dark depths of the lake.
Researchers sampled waters up to 150 m of water in Lake Mistassini, Quebec and compared their catch to diversity found in Lake Superior. Diverse populations of lake trout were once abundant in the cool waters of the Laurentian Great Lakes; however, native populations of deep-water lake trout are now only found in Lake Superior.
"At least two North American lakes outside the Laurentian Great Lakes are now known to have deep-water lake trout that differ from lake trout caught in shallow waters," says Mara Zimmerman, a post doctoral research associate at Michigan State University. "Similarities in the appearance of deep-water lake trout across lakes suggest that particular traits may help these animals to live in cold, dark, and high-pressure environments."
In Lake Mistassini, deep-water lake trout look different than the "lean" lake trout typically angled in the lake. The lean lake trout have streamlined bodies, long, pointy snouts, and . There are almost black in color. The deep-water lake trout are "pot-bellied" in appearance with a blunt snout. Together with colleagues Charles Krueger and Randy Eshenroder, Zimmerman has observed that deep-water lake trout in two lakes, Lake Mistassini and Great Slave Lake (Northwest Territories), have low buoyancies. Low buoyancies help lake trout swim in high-pressure environments. The deep-water lake trout in Great Slave Lake resemble the "siscowet" lake trout of Lake Superior, whereas those in Lake Mistassini resemble the Lake Superior "humper" lake trout.
Original Publication Information
Results of this study "Morphological and Ecological Differences Between Shallow- and Deep-water Lake Trout in Lake Mistassini, Quebec," are reported by Mara S. Zimmerman, Charles C. Krueger and Randy L. Eshenroder in the latest issue (Volume 33, No. 1, pp. 156-169) of the Journal of Great Lakes Research, published by the International Association for Great Lakes Research, 2007.
Contacts
For more information about the study, contact Mara Zimmerman, Great Lakes Fishery Commission, 2100 Commonwealth Boulevard, Suite 100, Ann Arbor, MI 48105, zimme154@msu.edu, (734) 662-3209 ext 26.
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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