Relative Reproductive Success of Supplemented Upper Yakima River Spring Chinook – Preliminary Report for Broodyear 2007
The Cle Elum Supplementation and Research Facility (CESRF) operates integrated hatchery program for Yakima River spring Chinook Salmon Oncorhynchus tshawytscha, designed to test whether artificial propagation can increase natural production and harvest opportunities while keeping ecological and genetic impacts within acceptable limits. Among the original goals for the CESRF monitoring program is performance of a population-scale productivity assessment. Recent advances in molecular genetic technologies have made such an assessment feasible, and a collaborative (CRITFC and WDFW) 5-broodyear (2007-2011) study was designed and initiated. The study will not be complete until 2019, although an initial analysis for broodyear 2007 was recently performed. Results for this analysis include: a) the proportion of adults passed upstream for natural spawning that were identified as having produced one or more adult progeny was relatively high: 82% and 80% for natural and hatchery origin females, 73% and 75% for natural and hatchery origin males, and 47% and 35% for natural and hatchery origin age 3 jack males; b) natural origin adults (sexes combined) used as hatchery broodstock produced on average 2.15 times more returning adult progeny than natural origin fish passed upstream for natural spawning; c) the average number of adult recruits-per-spawner within females and adult males, was similar for hatchery origin and natural origin fish spawning naturally, though average natural productivity of age 3 hatchery origin jack males was lower than for natural origin jacks. Within hatchery origin fish that spawned naturally, average productivity differed depending on which of the 3 acclimation sites the fish were released from as smolts, though these differences were not statistically significant.
Galbreath, P.F., I.J. Koch, S.R. Narum, K.I. Warheit, T.R. Seamons, T.W. Kassler, D.E. Fast, W.J. Bosch, M.V. Johnston, and C.R. Strom. Relative Reproductive Success of Supplemented Upper Yakima River Spring Chinook – Preliminary Report for Broodyear 2007. 2017. Columbia River Inter-Tribal Fish Commission Technical Report 17_08. Portland, Oregon. 17p.