Northwest Atlantic Mackerel (Scomber scombrus) Population Structure Evaluated using Otolith Stable Isotopes
Bibliographic record
Abstract
Stock assessments for Northwest Atlantic mackerel (Scomber scombrus) assume a single stock, comprised of northern and southern contingents, each with distinct natal regions in the US and Canada. I hypothesized that otolith δ18O and δ13C values would provide discrimination between these regions based upon hydrographic differences, and such information could illuminate seasonal migrations and contingent structure. Otoliths from regions throughout the North Atlantic Ocean were carefully milled to extract carbonates corresponding to the first year of life. Significant differences occurred in otolith isotope composition across the Atlantic basin, and within the Northwest Atlantic stock, despite annual variability. In the Northwest Atlantic, two separate natal habitats and associated contingents were supported for juvenile mackerel, but incursions by the northern contingent into US waters occurred in older fish (age>2). These findings indicate that stock structure assumptions should be revisited in the assessment and management of Northwest Atlantic mackerel.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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 teacher head, 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".