Diversity in freshwater life history in spring and summer Chinook Salmon from the Fraser River, Canada
Bibliographic record
Abstract
Abstract Objective We describe juvenile migration tactics for spring/summer-run populations of Chinook Salmon Oncorhynchus tshawytscha that spawn in tributaries of the Fraser River, Canada. Methods We trapped juveniles migrating from tributaries, and sampled juvenile Chinook salmon rearing in the Fraser River. Result In four tributaries, we found two dominant life history types within each population: a natal-stream-rearing variant in which juveniles spend a year in their natal stream before migrating to the sea as yearling smolts; and a fry migrant variant in which juveniles disperse downstream from spawning areas to the Fraser River main stem soon after emergence. In a fifth tributary, where flows are regulated, juveniles migrated as parr later in the spring. Juveniles colonized the Fraser River main stem in spring and were distributed throughout the accessible length of the main stem. Their relative density in nearshore habitats was similar to that observed in other rivers. Migrants spend up to a year in the main stem before smolting as yearlings. Conclusion The extensive year-round use of the Fraser River main stem appears to be unique among Chinook Salmon-producing watersheds, likely due to favorable environmental conditions in the main stem during the spring and summer months. The diversity of habitats used by these populations is an important consideration for the design of conservation programs that are intended to maintain or improve freshwater productivity.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".