Migration and rearing histories of chinook salmon (Oncorhynchus tshawytscha) determined by ion microprobe Sr isotope and Sr/Ca transects of otoliths

Canadian Journal of Fisheries and Aquatic Sciences
By: , and 

Links

Abstract

Strontium isotope and Sr/Ca ratios measured in situ by ion microprobe along radial transects of otoliths of juvenile chinook salmon (Oncorhynchus tshawytscha) vary between watersheds with contrasting geology. Otoliths from ocean-type chinook from Skagit River estuary, Washington, had prehatch regions with 87Sr/86Sr ratios of ~0.709, suggesting a maternally inherited marine signature, extensive fresh water growth zones with 87Sr/86Sr ratios similar to those of the Skagit River at ~0.705, and marine-like 87Sr/86Sr ratios near their edges. Otoliths from stream-type chinook from central Idaho had prehatch 87Sr/86Sr ratios ≥0.711, indicating that a maternal marine Sr isotopic signature is not preserved after the ~1000- to 1400-km migration from the Pacific Ocean. 87Sr/86Sr ratios in the outer portions of otoliths from these Idaho juveniles were similar to those of their respective streams (~0.708–0.722). For Skagit juveniles, fresh water growth was marked by small decreases in otolith Sr/Ca, with increases in Sr/Ca corresponding to increases in 87Sr/86Sr with migration into salt water. Otoliths of Idaho fish had Sr/Ca radial variation patterns that record seasonal fluctuation in ambient water Sr/Ca ratios. The ion microprobe's ability to measure both 87Sr/86Sr and Sr/Ca ratios of otoliths at high spatial resolution in situ provides a new tool for studies of fish rearing and migration.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Migration and rearing histories of chinook salmon (Oncorhynchus tshawytscha) determined by ion microprobe Sr isotope and Sr/Ca transects of otoliths
Series title Canadian Journal of Fisheries and Aquatic Sciences
DOI 10.1139/f04-167
Volume 61
Issue 12
Year Published 2004
Language English
Publisher NRC Research Press
Contributing office(s) Western Fisheries Research Center, Volcano Science Center
Description 15 p.
First page 2425
Last page 2439
Online Only (Y/N) N
Additional Online Files (Y/N) N