The authors propose to use otolith microstructure and microchemistry to study growth patterns and spatial structure of Snake River fall Chinook salmon with a specific objective of gaining understanding of the reservoir-type migrants. They hope to learn when and where these migrants spend their time during downstream migration. The proposal identifies the importance of the recently detected "reservoir" life history type of Snake River fall Chinook and provides a logical reasoning to refining when and where these fish reside and migrate within the Columbia River hydrosystem.

An enormous commitment has been made to understanding how flow, spill, temperature, sediment, load following, and transport affect the viability of the fall Chinook ESU, which has precarious status. This project will provide additional insight into the adaptation of fall Chinook to the modified Columbia River ecosystem.

The proposal suggests using recent advances in microchemistry along with standard microscopy to evaluate where in the hydrosystem fall Chinook were residing and growing prior to ocean entry, and then estimate food consumption rates. The methods are innovative (but used elsewhere with notable success) and have a potential to provide insights into the life cycle of fall Chinook unavailable traditionally.