Temporal and spatial responses of British Columbia steelhead (<i>Oncorhynchus mykiss</i>) populations to ocean climate shifts
Bibliographic record
Abstract
The pattern of temporal change in recruitment of steelhead trout ( Oncorhynchus mykiss ) entering the ocean between 1963 and 1990 was geographically coherent in all regions of British Columbia. A major increase in recruitment was evident for smolts entering the ocean after 1977. Subsequently, an out‐of‐phase response occurred after 1990, indicating that the effect of a possible 1990 regime shift had both temporal and geographical structure. Steelhead entering northern regions had increasing recruitment, while steelhead entering southern BC coastal regions had sharply decreasing recruitment. The evidence clearly indicates that the overall recruitment response since 1977 was primarily shaped by changes in marine (not freshwater) survival. Similar sudden changes in adult recruitment also appear to be occurring for other species of Pacific salmon in BC and Oregon, such as coho ( O. kisutch ), which appear to occur suddenly and show considerable persistence. A possible explanation for the change is that ocean productivity declined in coastal regions of southern BC after 1990, reducing the marine growth of juvenile salmon. The Bakun upwelling index shows a pattern of geographical coherence along the west coast of North America that could in principle explain the observed pattern of changes in recruitment. However, no evidence for a temporal shift in this index occurring around 1977 and 1990 is apparent. The reason for the sudden and persistent decline in ocean survival is therefore uncertain.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.022 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".