The controls of sedimentary links on the spatial distribution of Atlantic salmon («Salmo salar») juveniles and spawning activity along rivers in the Gaspé Peninsula, Canada
Bibliographic record
Abstract
The longitudinal trend in the size of a river’s bed material is best represented as being composed of several discrete units, called sedimentary links, in which each sedimentary link is initiated by a source of coarse sediment, and the bed material becomes progressively finer in the downstream direction. In this study, the concept of sedimentary links is applied to salmon rivers in the Gaspé Peninsula of Quebec, Canada, which have previously not been studied in the context of sedimentary links. Also, the relationship between the sedimentary links and the distributions of Atlantic salmon (Salmo salar) juveniles and spawning activity along these rivers is tested.A key finding in this study is that the sedimentary links of the Gaspé rivers are subdivided into not only source zones (experiencing a spatially continuous supply of coarse sediment) and fining segments (where the sediment becomes progressively finer downstream), but also an additional component not identified in earlier studies, which we call intermediate zones, in which the channel experiences regular but spatially discontinuous supplies of coarse sediment, producing “disturbed downstream fining”.Using data on salmon juvenile and redd densities provided by local wildlife managers, it was found that greater net gains in older juvenile densities generally occur in source zones and intermediate zones, rather than in the finer-sediment sections of fining segments. There is also a strong, positive correlation (R2 = 0.91, p = 0.001) between a river’s overall density of juveniles and the proportion of the river length that is occupied by either source zones or intermediate zones. Spawning activity is generally the highest in fining segments and intermediate zones, and lowest in source zones. There is also a significant, negative correlation (R2 = 0.87, p = 0.001) between the size of a river’s salmon run and the distance separating the river mouth from the nearest boulder-rich intermediate zone or source zone; we speculate that the proximity of such a zone to the river mouth influences the survival rates of juveniles during the winter immediately preceding their seaward migration.
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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 | 0.001 |
| 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 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".