North Pacific Anadromous Fish Commission

Technical Report 23

Table of Contents

Tracking the Marine Migrations of Coho and Chinook Salmon

Authors:
Micah Quindazzi, Will Duguid, Tanya Brown, and Francis Juanes

Abstract:
During their marine life stage, Chinook (Oncorhynchus tshawytscha) and coho salmon (Oncorhynchus kisutch) from watersheds connected to the Salish Sea display two distinct migration phenotypes; Strait of Georgia resident and out-migrant. Knowledge of Chinook and coho salmon marine migrations has been limited to tagged individuals caught by anglers and researchers. Microchemical techniques, specifically trace element and stable isotope analyses, can be used to identify the movement of fish in their marine environment. The goal of this study was to identify the microchemical signatures of different marine regions and to predict the proportion of escapements from Southern BC hatcheries that were residents or migrants. Initial results on coho salmon samples indicate that otolith trace elements can be used to determine differences between marine regions with over a 90% classification success rate. In 2017, roughly 70% of coho from Southern BC were Strait of Georgia residents, and in 2018 roughly 40% of coho from a few Southern BC river systems remained as residents. Otolith microchemistry shows promise as a technique to identify marine migration life history types amongst salmon.

DOI:
https://doi.org/10.23849/npafctr23/ww2-hqp

Citation

Quindazzi, M., W. Duguid, T. Brown, and F. Juanes.  2024.  Tracking the marine migrations of coho and Chinook salmon.  N. Pac. Anadr. Fish Comm. Tech. Rep. 23: 77–81.  https://doi.org/10.23849/npafctr23/ww2-hqp