EAPSI: Characterization of dissolved free amino acids in hatchery system water - a salmon hatchery case study

Lemanski Joseph R, Junction City OR

Investigators

Abstract

For many decades, salmon in the Pacific Northwest have been sought after for a multitude of reasons. Due to regional declines in adults returning to their natal rivers to spawn every year, the rearing and release of hatchery salmonids has been utilized for many decades. Unfortunately, hatchery raised salmon have shown a significant decrease in home stream fidelity and impose an assortment of ecological issues due to increased interaction with wild populations. One proposed explanation for the lack of home stream fidelity in hatchery salmonids is inadequate learning of chemical cues in natal river water. The purpose of this study is to determine if the chemical nature of natal river water is altered by simple, daily hatchery operations. This research will be conducted in collaboration with Dr. Hiroshi Ueda, an expert in dissolved free amino acids (DFAA's) in salmonid imprinting and homing, at the Hokkaido University in Japan. It is well understood that salmon use olfaction to identify distinct chemical cues of natal river water when navigating to their natal rivers to spawn. However, the distinct set, or "bouquet" of chemicals that salmon use for this phenomenon has yet to be identified. Recently, considerable attention has been directed towards DFAA's as a set of molecules that salmon use to navigate and identify their natal rivers. Research has shown that salmonids possess the ability to distinguish between certain water sources based on their DFAA compositions. High-performance liquid chromatography (HPLC) will be used to analyze the content of DFAA's in river water. By analyzing water collected from certain locations within a hatchery setting, it will be determine if current hatchery operations may significantly alter the chemical nature of their source river water. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.