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The goal of this U.S. Army Corps of Engineers (USACE) - funded study that began in 2004 is to determine if the smolt-to-adult return rates (SARs), transport/in-river ratio, and differential post-hydropower system mortality of transported and in-river Chinook salmon and steelhead are related to their size and time of ocean entry. Juvenile spring/summer Chinook and steelhead are PIT-tagged each week of the migration at Lower Granite Dam, and either barged or returned to the river to migrate. A portion of the in-river migrants are collected at Bonneville Dam and re-measured to calculate growth during migration. When adult returns are complete, SARs and Transport Benefit ratios will be calculated and correlated with biological and physical conditions in the river, plume, and ocean environment. This information can then be used to make management decisions on when to release fish from hatcheries, and whether to transport smolts or leave them in the river to optimize SARs. Annual reports of project progress and a final report will be provided to the USACE upon project completion. Seasonal transport data