Chinook passed above Landsburg Dam


The fish passage system allows us an opportunity to count the number of Chinook moving upstream and to collect information about them. While there are no hatchery releases of Chinook in the Cedar River, hatchery Chinook are released at other locations within the Lake Washington basin. Some of these hatchery Chinook make their way into the Cedar River and up to Landsburg Dam. They are identified by their missing (clipped) adipose fin (between the dorsal and tail fins). Looking just at the female Chinook you can see that each year some hatchery (clipped) Chinook use the Landsburg Fish Passage system. In the first three years of fish passage there were also some natural Chinook (unclipped adipose fin) that also used Landsburg Fish Passage. It is natural for Chinook to explore areas and pioneer new areas if they are good areas for them to spawn. The increase in unclipped Chinook in 2006 - 2008 is likely due to Chinook returning to the area above Landsburg Dam from Chinook that spawned in that area in 2003-2005. Seattle Public Utilities has collected samples from each of the Chinook passed above Landsburg Dam. Researchers at the University of Washington are doing a genetic analysis of these samples to determine their parents, and estimate the number that are offspring from the fish that spawned above Landsburg Dam. Fish Passage above Landsburg Dam is providing more salmon spawning habitat for the Cedar River.


View full-sized graph >