This project is focused on investigating juvenile Spring Chinook salmon dispersal patterns based on spawner origin and riverscape conditions among hatchery vs. wild fish in Catherine Creek. Catherine Creek is located in the Grande Ronde basin, in Northeast Oregon. This watershed has experienced increased temperatures and habitat degradation due to anthropogenic impacts and the ongoing climate crisis. We hope to better understand adult distribution and juvenile dispersal patterns in relation to recent restoration projects and the population-level benefit of these management actions.
On Catherine Creek, there is a high detection rate of spawners both at an adult collection facility (weir) and on spawning grounds, with >95% of known spawning occurring upstream of the weir. As fish migrated to spawning habitat, they were caught in the trap and received a dorsal PIT tag and tissue samples were taken before being passed upstream. This ensured that fish recovered on the spawning ground had a high likelihood of being matched to the genetic sample collected at the weir. During spawning ground surveys from August-September 2023, PIT tag identification (when applicable), waypoints, and a second tissue sample were collected from recovered adult fish carcasses.
During the 2024 field season, we will extensively sample parr throughout the juvenile rearing distribution to obtain an unbiased sample of the population. We will use PIT tags and collect tissue samples from juveniles from rearing habitats. All samples, from adult and juvenile life stages, will be genotyped and a parentage analysis will be performed to relate juveniles back to their adult spawning locations. The pedigree reconstruction analyses will allow us to assign juveniles to spawning pairs (two-parent assignments) and individual females (single-parent assignments); location of the female parent on spawning grounds can act as a proxy for the redd location.
With this study, we aim to better understand spatial ecology of adult and juvenile Chinook salmon in Catherine Creek, and how dispersal patterns can better inform management efforts among hatchery and wild fish. The study will provide recommendations to restoration practitioners for the placement and design of future projects to ensure that the findings are applied in a practical way, and will beneficial for the management and conservation of the Chinook population in the area.
This project is a collaboration between the Columbia River Intertribal Fish Commission (CRITFC), the Confederated Tribes of the Umatilla Indian Reservation (CTUIR), the Oregon Department of Fish and Wildlife (ODFW), and Oregon State University.
