Identification of the natal origin of Lake Michigan steelhead using otolith chemistry

Grant: # 1298

Grant Amount: $196,083.82

Board Decision Year: 2013

Central Michigan University - Department of Biology and Institute for Great Lakes Research (Mt. Pleasant)

Department of Biology and Institute for Great Lakes Research

Pangle, Kevin ([email protected]) 989-774-3185

GLFT - Ecosystem Health and Sustainable Fish Populations-D - Ecological and biological fisheries research to inform management

Project Details

This study explored the use of otolith microchemistry as a natural marker for determining natal tributary origins of Lake Michigan steelhead. Researchers analyzed the otolith chemistry of juvenile steelhead collected over a four-year period (2012–2015) from 34 Lake Michigan tributaries and five different hatcheries. Their results showed that otolith chemistry could differentiate the natal origin of Lake Michigan steelhead, with the relative accuracy being influenced by spatial resolution and temporal variation. Using otolith chemistry, researchers were able to differentiate between hatchery and natural origin fish in 19 stocked streams at a mean accuracy of greater than 95 percent. For naturally produced fish, their mean accuracy at correctly classifying fish to their specific collection site ranged between 75 percent and 83 percent, depending on the year, with several sites exhibiting 100 percent accuracy. Classification of one year-class based on signatures developed from another year-class significantly reduced accuracy, demonstrating the importance of inter-annual variation in otolith chemistry signatures. Overall, researchers’ findings demonstrate the ability to use naturally occurring, trace element otolith signatures to differentiate natal tributaries of Lake Michigan steelhead at fine and coarse geographic resolutions. Further, this research provides a strong foundation for future studies to determine the natal origins of adult steelhead, benefiting the management of this species in Lake Michigan and tributaries.


Final Report
View - Pangle_et_al_Project_2013.1298_Final_Report_v3.docx