EAPSI: Using Genetics to Compare Olfactory Imprinting Ability in Hatchery and Wild Salmon from the Pacific Northwest

Self Katharine E, Corvallis OR

Investigators

Abstract

This award supports research to compare olfactory imprinting abilities of hatchery and wild salmon from the state of Oregon in the Pacific Northwest region of the United States. The conflict between hatchery-raised fish and wild-origin fish has reached a crescendo in the last decade due to the heavy-handed management and lofty conservation goals both in Japan and the United States. Salmonid species are culturally important, economically important, scientifically important and struggling or, worse, disappearing in some locations. Although Japan and the United States have different modern views of the value of salmon, both countries have traditionally managed salmon using hatchery systems and face similar issues today. This study will support an ongoing effort to understand the underlying mechanisms in salmonid olfactory systems and, therefore, homing behavior strategies. This research will be conducted in collaboration with Dr. Hiroshi Ueda who leads a world-renowned lab at Hokkaido University in Sapporo, Japan where he focuses on the study of salmon olfactory homing methods. The study will be based on previous research in the Ueda lab on the involvement of hormones in olfactory imprinting and homing in chum salmon (Oncorhynchus keta). The Chinook salmon (Oncorhynchus tshawytscha) specimens to be used will be obtained from Western Oregon streams and reservoirs prior to departure. Data regarding the gene expression levels of thyrotropin-releasing hormone (TRHa/b) and an essential subunit of the N-methyl-D-aspartate receptor (NR1) will be measured using information from the prepared brain including the olfactory bulb, the telencephalon, and hypothalamus. TRH levels have been shown to increase during downstream migration to the sea, and higher levels of NR1 expression have correlated with increased stream odor discrimination ability in some juvenile salmonids native to Japan. This study will allow for comparison of these findings to the results from salmonid species native to the Pacific Coast of the United States. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Japan Society for the Promotion of Science.