Spawning time variation in Icelandic summer-spawning herring (Clupea harengus)
Bibliographic record
Abstract
Different fish stocks of the same species are defined by spatial and temporal differences in spawning, though spawning time can vary within and among stocks. Here we address spawning time variation in Icelandic summer-spawning (ISS) Atlantic herring ( Clupea harengus ). We do so by examining influencing factors that include variation in stock size structure, spawning experience (recruit vs. repeat spawners), spawning stock biomass (SSB), sea temperature, and combinations thereof. Our results, based on temporal variation in ovary weight (OW), relative ovary weight (RG), and maturation stage, across a time series of nearly 50 years and eight length classes of ISS herring, show that spawning occurs over a relatively invariant 30-day period defined by day-of-the-year. Logistic regression analyses and temporal development in OW and RG show that maximum spawning invariably occurs on day-of-the-year 200 ± 15 days, and seasonal variation in mesenteric fat content is physiologically consistent with the timing. We show that the smaller recruit spawners tend to spawn ~17 days later, on average, than the larger repeat spawners. Spawning occurs ~7 days later when SSB is greater than the long-term average, and spawning may be delayed by as much as 10 days during periods of colder than average ocean temperature.
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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 | 0.000 |
| 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".