Influence of sex and reproductive status on seasonal movement of Lake Sturgeon in Namakan Reservoir, Minnesota–Ontario

Transactions of the American Fisheries Society
By: , and 

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Abstract

We evaluated the influence of sex and reproductive condition on seasonal distribution and movement patterns of Lake Sturgeon Acipenser fulvescens in Namakan Reservoir, Minnesota–Ontario. Blood samples were collected from 133 Lake Sturgeon prior to spawning and plasma concentrations of testosterone and estradiol-17ß were analyzed using radioimmunoassay. Steroid concentrations were used to determine sex and the reproductive stage of each sturgeon. A subset of 60 adults were implanted with acoustic transmitters prior to spawning in 2007 and 2008. Movement was monitored using an array of 15 stationary receivers covering U.S. and Canadian waters of Namakan Reservoir and its tributaries. Of the monitored sturgeon, there was no significant difference in the minimum distance traveled between sexes or among seasons. Site residency did not differ between sexes but differed significantly among seasons, and Lake Sturgeon of both sexes had higher residency during winter (mean = 24 d). Five females implanted with transmitters were characterized as presumed reproductive and 14 as nonreproductive based on plasma steroid concentrations. In general, movement patterns (i.e., migration) of presumed reproductive females corresponded positively with availability of spawning habitat in tributaries. Moreover, presumed reproductive females traveled greater distances than nonreproductive females, particularly during prespawn, spawning, and fall time periods. Distance traveled by presumed reproductive females was highest in the fall compared with other seasons and may be linked to increased energy requirements during late oogenesis before spawning in spring. Combining movement data with information on Lake Sturgeon reproductive status and habitat suitability provided a robust approach for understanding their seasonal migration patterns and identifying spawning locations.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Influence of sex and reproductive status on seasonal movement of Lake Sturgeon in Namakan Reservoir, Minnesota–Ontario
Series title Transactions of the American Fisheries Society
DOI 10.1080/00028487.2012.720625
Volume 142
Issue 1
Year Published 2013
Language English
Publisher Taylor & Francis
Contributing office(s) Coop Res Unit Leetown
Description 11 p.
First page 10
Last page 20
Country Canada, United States
State Minnesota, Ontario
Other Geospatial Namakan Reservoir