Estimating westslope cutthroat trout (Oncorhynchus clarkii lewisi) movements in a river network using strontium isoscapes
Muhlfeld CC, Thorrold SR, McMahon TE, Marotz B. 2012. Estimating westslope cutthroat trout (Oncorhynchus clarkii lewisi) movements in a river network using strontium isoscapes. Canadian Journal of Fisheries and Aquatic Sciences. 69:906–915
We used natural variation in the strontium concentrationand isotope composition of streamwaters and corresponding values recorded in otoliths of westslope cutthroat trout (Oncorhynchus clarkii lewisi) to examinemovements during their life history in a large river network. We found significant spatial differences in Sr:Ca and 87Sr:86Srvalues (strontium isoscapes) within and among numerous spawning and rearing streams that remained relatively constantseasonally. Both Sr:Ca and 87Sr:86Sr values in the otoliths of juveniles collected from nine natal streams were highly correlatedwith those values in the ambient water. Strontium isoscapes measured along the axis of otolith growth revealed that almosthalf of the juveniles had moved at least some distance from their natal streams. Finally, otolith Sr profiles from threespawning adults confirmed homing to natal streams and use of nonoverlapping habitats over their migratory lifetimes. Ourstudy demonstrates that otolith geochemistry records movements of cutthroat trout through Sr isoscapes and therefore providesa method that complements and extends the utility of conventional tagging techniques in understanding life historystrategies and conservation needs of freshwater fishes in river networks.
- Type
- Journal Article
- Authors
- Muhlfeld, Clint; Thorrold, Simon; McMahon, Thomas; Marotz, Brian
- Units
- CRCO , GLAC
- Keywords
- Aquatic Studies, Fisheries, Oncorhynchus clarkii lewisi, Spawning, Westslope cutthroat trout
- Subjects
- Ecological Framework: Biological Integrity | Focal Species or Communities | Freshwater Communities