title: Using hierarchical models to estimate effects of ocean anomalies on north-west Pacific Chinook salmon Oncorhynchus tshawytscha recruitment.
abstract: The high variability in survival over the past three decades of north-west Pacific Chinook salmon Oncorhynchus tshawytscha is summarized for 24 stocks and analysed using hierarchical Bayesian models. Results from a simple model indicate that recruitment anomalies appear to be correlated in time and space. A simple model with a covariate based on basin-scale effects (Pacific Decadal Oscillation and El Niño Southern Oscillation) and local-scale effects (sea surface temperature, SST anomaly) was introduced to explain this variability. The model still exhibited residual patterns that were removed when a random-walk component was added to the model. The analysis indicates that recruitment is negatively related to SST anomaly for all stocks and the effect of basin-scale variables is negligible. The effect of climate over the next century is expected to result in estimated recruitment declining by an average of 13% for O. tshawytscha stocks coastwide.
authors.affiliation: Columbia River Inter-Tribal Fish Commission, 729 NE Oregon St, Suite 200, Portland, OR 97232, USA. shar@critfc.org
authors.forename: R
authors.initials: R
authors.lastname: Sharma
authors.forename: M
authors.initials: M
authors.lastname: Liermann
mesh_terms: D000818:Animals; D057231:Climate Change; D008954:Models, Biological; D010140:Pacific Ocean; D011157:Population Dynamics; D012474:Salmon / Q000502:physiology*