Life history variation in upper Columbia River Chinook salmon (<i>Oncorhynchus tshawytscha</i>): a comparison using modern and ~500-year-old archaeological otoliths
Bibliographic record
Abstract
Conservation planning often occurs only after a species has been extirpated from portions of its historical range and limited information is available on life history diversity prior to development. To provide information on Chinook salmon ( Oncorhynchus tshawytscha ) life history before and after local extirpation, we examined the chemical (87Sr:86Sr, Sr:Ca) and structural composition of modern and archaeological otoliths from the upper Columbia River. We compared otoliths from modern spring (yearling migrant, n = 15) and summer–fall (yearling (n = 7) and subyearling (n = 12) migrants) runs with those from extirpated runs (n = 8) to estimate the number of and similarity among natal environments and reconstruct aspects of the migratory history. Presumptive natal sources were most similar between the archaeological collections and the modern summer–fall run. Chinook salmon represented by the archaeological otoliths also displayed life history traits, including size at freshwater emigration and adult size at return to fresh water, most similar to the summer–fall subyearling run. These data indicate that there is the potential to maintain aspects of predevelopment Chinook salmon life histories in the Columbia River, and strategies that promote maintenance of that life history diversity may be warranted.
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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 | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".