BROOD YEAR 2018 JUVENILE SALMONID PRODUCTION AND PASSAGE INDICES AT RED BLUFF DIVERSION DAM

Brood year 2018 (BY2018) juvenile winter Chinook salmon estimated passage at Red Bluff Diversion Dam (RBDD) was 1,168,263 for fry and pre-smolt/smolts combined. The fry-equivalent rotary trap juvenile production index (JPI) was the highest value reported in the last five years; estimated at 1,477,529 with the lower and upper 90% confidence intervals (CI) extending from 824,706 to 2,130,352 juveniles, respectively. The estimated egg-to-fry (ETF) survival rate, based on the BY2018 winter Chinook fry-equivalent JPI was 26.6%, slightly above the 21-year average ETF survival rate of 25.0%. The range of ETF survival rates based on the 90% CI were 14.9% to 38.4%.