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Changes in a population of exotic rainbow smelt in Lake Superior: Boom to bust, 1974-2005

Journal of Great Lakes Research

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DOI: 10.3394/0380-1330(2007)33[75:CIAPOE]2.0.CO;2

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Abstract

Changes in a population of rainbow smelt (Osmerus mordax) in the Apostle Islands region of Lake Superior were chronicled over a 32-yr time series, 1974-2005. At the beginning of the time series, rainbow smelt was the predominant prey species, abundance of lake herring (Coregonis artedi) was very low, and the dominant predator was stocked lake trout (Salvelinus namaycush). Following a period of successful lake trout stocking in the 1970s, the rainbow smelt population declined sharply in 1980, largely through mortality of adult fish and subsequent poor recruitment. In the succeeding 4 years, rainbow smelt populations reached historic low levels, resulting in reduced food resources for both wild and stocked lake trout. During 1985-1990 lake herring stocks began a spectacular recovery following the appearance of a very strong 1984 year class and subsequent 1988, 1989, and 1990 year classes. Rainbow smelt benefited from the high abundance of young lake herring as an alternate prey source for lake trout and showed a partial recovery in the late 1980s. However, a growing lake trout population coupled with an 8-yr period of low herring reproduction after 1990 resulted in a diminished rainbow smelt population dominated by age-1 and 2 fish and showing a pattern of alternating recruitment attributed to cannibalism. Low productivity of rainbow smelt and intermittent production of herring over the past decade has left lake trout populations with a diminished prey base. Although lake trout recovery benefited from the presence of rainbow smelt as a prey resource, the Lake Superior fish community was fundamentally altered by the introduction of rainbow smelt.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Changes in a population of exotic rainbow smelt in Lake Superior: Boom to bust, 1974-2005
Series title:
Journal of Great Lakes Research
DOI:
10.3394/0380-1330(2007)33[75:CIAPOE]2.0.CO;2
Volume
33
Issue:
SUPPL. 1
Year Published:
2007
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
75
Last page:
90
Number of Pages:
16