![A grayscale U.S. Fish and Wildlife Service logo](/sites/default/files/styles/large_square/public/staff-profile-image/2024-03/default_profile_image.jpeg?h=1e66e246&itok=AB4QLjXy)
![Assessing superimposition of listed tule fall Chinook salmon redds using aerial and ground surveys on the White Salmon River, WA](/carp/sites/default/files/styles/max_325x325/public/documents/2024-03/draft-redd-superimposition-poster-2024-2.pdf-p1.jpeg?itok=9MjToZEM)
Hatchery upriver bright (URB) fall Chinook salmon are straying into the White Salmon River (Figure 1). ESA-listed tule fall Chinook population in the White Salmon River spawns earlier (Sept – Oct) than URBs (late Oct – Nov). Tule redds at risk to superimposition which may displace eggs and reduce egg-to-fry survival.
A surprisingly high incidence of tule redds monitored were superimposed by URBs in 2022 and 2023. Counts of redds superimposed from aerial surveys can be especially valuable for high-density spawning areas. Efficient processing of aerial imagery requires high performance computing environment. • Aerial drone surveys can provide high-resolution georeferenced imagery of a more expansive area of spawning grounds.
Next steps: Compare count estimates of redds superimposed from ground surveys with aerial surveys. Estimate aerial observer error among four independent observers. Prepare for 2024 aerial surveys using a Skydio X10 drone with onboard AI for obstacle avoidance.
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draft-redd-superimposition-poster-2024-2.pdf34.41 MB | 34.41 MB |