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Fish Olfaction and Homing Research

Research to improve imprinting/homing and reduce straying of Pacific salmon through better understanding their olfactory function.

Fish ladder at Lower Granite. Credit: NOAA Fisheries

Fish have an acute sense of smell. Olfaction influences every aspect of their lives (e.g., feeding, reproduction, migration, and predator avoidance). We study the critical role of olfaction in different fishes' life history and ecology using an integrative approach that includes molecular biology, electrophysiology, and field-based behavior. Our work focuses on olfactory imprinting and homing in Pacific salmon.

Pacific salmon are famous for their homing migrations from the ocean to their river of origin to spawn. Before their seaward migration, juvenile salmon learn (imprint to) specific odors associated with their natal stream. Maturing adults use retained odor memories to guide their homing migration. Salmon that do not experience their natal water during appropriate juvenile stages are more likely to stray to non-natal sites. Hatchery or wild salmon that deviate from their natal site can impact conservation and recovery efforts due to negative genetic and ecological interactions.



Rafts being prepared for staff to survey a Washington state river for returning salmon carcasses. Photo: NOAA Fisheries

Our research in this area aims to:

  • Identify hatchery rearing and release strategies that minimize straying to reduce negative interactions with wild salmon. 
  • Develop tools to reduce straying associated with the transport of juvenile salmon.
  • Identify and exploit olfactory imprinting's neural mechanisms to develop cost-effective assays for successful imprinting to aid in salmon management.
  • Identify the effects of ocean acidification on sensory physiology in salmonids and other marine fish.


  • Evaluation of methods to increase homing fidelity in hatchery salmon.
  • Development of imprinting paradigms for salmon supplementation programs.
  • Molecular assays for olfactory imprinting.
  • Effects of elevated CO2 on olfactory physiology in salmonids.

Dr. Andrew Dittman collects a water sample for analysis of odors
that may influence salmon imprinting and homing. Photo: NOAA


Scanning electron microscopy (SEM) image of a
salmon olfactory rosette. Photo: NOAA Fisheries


  • U.S. Fish and Wildlife
  • Oregon Department of Fish and Wildlife
  • Oregon State University
  • University of Washington
  • NC State University
  • Texas A&M University
  • University of North Carolina-Wilmington
  • Yakama Nation
  • Confederated Tribes of the Warm Springs Reservation
  • Allen Institute
  • Leibniz Institutes


Adam Luckenbach, Environmental Physiology Program Manager

Last updated by Northwest Fisheries Science Center on February 27, 2023