Diel Reproductive Periodicity of Haddock in the Southwestern Gulf of Maine
Bibliographic record
Abstract
Abstract We studied a population of Haddock Melanogrammus aeglefinus in the Gulf of Maine to determine whether it exhibits diel spawning periodicity. Commercial fishing vessels were chartered for 25 dedicated long-lining trips to collect sexually mature Haddock in the Stellwagen Bank National Marine Sanctuary at locations identified by commercial fishers as having spawning aggregations. In order to examine diel effects on Haddock reproduction, the changes in CPUE and percentages of male and female Haddock of all reproductive maturity stages, as well as gonadosomatic index (GSI), were observed across a 24-h diel cycle. The comparison of diel patterns among different maturation stages was used to differentiate diel periodicity due to spawning from feeding behavior. Diel periodicity was observed for the proportion of males and females in the catch, the proportion and CPUE of male and female maturation stages most indicative of imminent spawning, and for female GSI. Although spawning occurred throughout the diel cycle, peak spawning of females occurred during the evening hours (1700–2100 hours) and gradually declined to low values during the day at 0900 hours. In an apparent contradiction male spawning stages were uniformly high except for lows during the night between 2100 and 0100 hours. We hypothesize that this pattern is consistent with lekking behavior where strong competition among spawning-ready males during courtship would reduce their feeding activity during the peak spawning hours. Strong annual differences in diel periodicity may have resulted from different temporal patterns in the spawning season or density dependence, or both.
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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) | 0.001 | 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".