Non-Native Species
Alewife | Brown Trout | Carp | Chinook Salmon | Coho Salmon | Pink Salmon | Rainbow Smelt | Rainbow Trout | Round Goby | Ruffe | Sea Lamprey | White perch
The fish listed above have been introduced, either intentionally or accidentally, into the Great Lakes. Also called "exotic" or "nonindigenous" species, these newcomers can cause trouble by changing the ecological balance of the lakes and, sometimes, crowding out native species. Some non-native species are ecologically harmless and or even beneficial, but others cause great harm.
For example, the sea lamprey (shown in the illustration) is a predator that attaches itself to a fish, rasps a hole with its large sucking disk, and sucks blood and body tissues until it becomes satiated or the victim dies. Sea lampreys have caused great damage to the lake trout, whitefish, and burbot populations in the Great Lakes. Before the lamprey invasion of Lake Superior (prior to 1952), the lake trout harvest averaged about 4.5 million pounds; by 1960, it was less than 500,000 pounds.
For more information about these non-native species, see the Wisconsin Sea Grant nonindigenous species Web site.
See also Lake Michigan, Lake Superior, Lake Huron, Lake Erie, or the complete listing.
copyright 2001 University of Wisconsin Sea Grant Institute
 |
|
