Iteroparity in Columbia River summer-run steelhead (Oncorhynchus mykiss): implications for conservation
Bibliographic record
Abstract
We used ultrasound imaging and passive integrated transponder (PIT)-tagging programs to assess maturation status and iteroparity patterns in summer-run steelhead (anadromous rainbow trout, Oncorhynchus mykiss ) of the interior Columbia River Basin (Pacific Northwest, USA). Postspawn kelts examined in downstream fish bypass systems at Columbia River and Snake River dams were disproportionately female (>80%) and majorities were of wild origin, unlike prespawn steelhead at these sites. Annual repeat migration estimates varied from 2.9% to 9.0% for kelts tagged at lower Columbia River dams (n = 2542) and from 0.5% to 1.2% for Snake River kelts (n = 3762). Among-site differences reflected greater outmigration distance and additional dam passage hazards for Snake River kelts. There was also strong evidence for condition-dependent mortality, with returns an order of magnitude higher for good- versus poor-condition kelts. Disproportionately more females and wild fish also returned, providing potentially valuable genetic and demographic benefits for the Columbia River’s threatened steelhead populations. Results overall provide baseline data for evaluating kelt mortality mitigation efforts and basic life history information for steelhead conservation planning.
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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 | 0.000 |
| 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) | 0.000 | 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".