Estimating westslope cutthroat trout (Oncorhynchus clarkii lewisi) movements in a river network using strontium isoscapes

Canadian Journal of Fisheries and Aquatic Sciences
By: , and 

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Abstract

We used natural variation in the strontium concentration (Sr:Ca) and isotope composition (87Sr:86Sr) of stream waters and corresponding values recorded in otoliths of westslope cutthroat trout (Oncorhynchus clarkii lewisi) to examine movements during their life history in a large river network. We found significant spatial differences in Sr:Ca and 87Sr:86Sr values (strontium isoscapes) within and among numerous spawning and rearing streams that remained relatively constant seasonally. Both Sr:Ca and 87Sr:86Sr values in the otoliths of juveniles collected from nine natal streams were highly correlated with those values in the ambient water. Strontium isoscapes measured along the axis of otolith growth revealed that almost half of the juveniles had moved at least some distance from their natal streams. Finally, otolith Sr profiles from three spawning adults confirmed homing to natal streams and use of nonoverlapping habitats over their migratory lifetimes. Our study demonstrates that otolith geochemistry records movements of cutthroat trout through Sr isoscapes and therefore provides a method that complements and extends the utility of conventional tagging techniques in understanding life history strategies and conservation needs of freshwater fishes in river networks.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Estimating westslope cutthroat trout (Oncorhynchus clarkii lewisi) movements in a river network using strontium isoscapes
Series title Canadian Journal of Fisheries and Aquatic Sciences
DOI 10.1139/f2012-033
Volume 69
Issue 5
Year Published 2012
Language English
Publisher National Research Council Canada
Publisher location Ottawa
Contributing office(s) Northern Rocky Mountain Science Center
Description 10 p.
First page 906
Last page 915
Online Only (Y/N) N
Additional Online Files (Y/N) N