Estimating habitat capacity for spring-run Chinook salmon and steelhead in the North Fork Feather River Watershed

We estimated thermal suitability and habitat capacity for spring-run Chinook salmon (Oncorhynchus tshawytscha) and steelhead (Oncorhynchus mykiss) within the North Fork of Feather River upstream of Lake Oroville, with particular focus on areas upstream of Rock Creek Dam that may be appropriate for reintroduction. Thermal suitability of stream habitat for areas of interest in years 2014 through 2017 was estimated using simple linear regression models for temperature, using elevation, day-of-year, and remotely sensed land surface temperature as covariates. Eight-day mean water temperatures were estimated for all stream reaches, and evaluated for the relevant life-stages of each fish species using criteria for optimal and tolerable temperatures. Simple estimates of capacity (numbers of fish per generation) were also estimated based on geomorphic habitat type and predicted temperature. We found spawning and incubation life-stages for both species to be seasonally limited by temperature throughout the NF Feather, while juvenile rearing was less constrained by temperature. There appears to be capacity for reintroduction of steelhead and perhaps spring-run Chinook salmon in the reaches upstream of Rock Creek Dam. Substantial additional capacity appears to occur upstream of natural migration barriers on Indian Creek and Spanish Creek, and in tributaries upstream of Lake Almanor. 2020 NMFS (National Marine Fisheries Service) SWFSC (Southwest Fisheries Science Center) Submitted https://doi.org/10.25923/a9n9-bn08 Public Domain 1862