Bomb Radiocarbon Validates Age and Long‐Term Growth Declines in American Plaice in the Southern Gulf of St. Lawrence
Bibliographic record
Abstract
Abstract The growth rate and size composition of American Plaice Hippoglossoides platessoides in the southern Gulf of St. Lawrence has changed markedly over the past 40 years. The size at age recorded in commercial fisheries and research survey data has declined, particularly through the mid‐1980s. Females of the 1969 cohort grew to an estimated maximum length of 59 cm (males, 42 cm); the 1994 cohort grew to a much smaller maximum of 37 cm (29 cm for males). There is no indication of any reverse trend in growth or size at age in the 2000s, despite reduced harvests and warmer water temperatures. Incorrect aging methods are not the reason for the observed growth trends. Ages were determined by counting the growth increments visible on the surface of whole otoliths, and there is no bias in ages determined by this method (as opposed to those from thin‐sectioned otoliths). The accuracy of ages determined by reading whole otoliths was validated to at least 27 years (±2 years) by bomb radiocarbon assays of 39 otoliths collected between 1971 and 1986. While commercial fishing may have contributed to past declines in plaice growth, ongoing natural mortality may be keeping size at age and the growth rate low despite the recent increases expected from low fishing mortality and higher water temperatures.
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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 | 0.001 | 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 | 0.000 | 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".