Stock Structure Of Atlantic Cod (Gadus Morhua) Off Newfoundland And Labrador Determined From Genetic Variation
Bibliographic record
Abstract
No abstracts are to be cited without prior reference to the author.The purpose of this study was to determine population structure of Atlantic cod (Gadus morhua) off Newfoundland and Labrador, with emphasis on the relationship between inshore and offshore spawning groups. Variation at seven microsatellite loci (Gmo3, Gmo8, Gmo19, Gmo34, Gmo35, Gmo36, and Gmo37) and SypI was surveyed in approximately 5,230 mature cod from 19 locations sampled mostly during the spawning period. FST estimates by locus were: Gmo3 0.0068, Gmo8 0.0047, Gmo19 0.0027, Gmo34 0.0162, Gmo35 0.0028, Gmo36 0.0069, Gmo37 0.0038, and SypI 0.0374, with the mean over all loci of 0.0080. Overall, the cod populations surveyed tended to conform to an isolation by distance structure, with cod from more distant locations tending to be more genetically distinct. Among offshore sites, the Flemish Cap population (NAFO Div. 3M) was the most distinctive, and among inshore sites the Gilbert Bay population in southern Labrador (2J) was the most distinctive. In NAFO Divs. 3KL, no significant genetic differentiation was observed among inshore northern cod sampled in four bays (Notre Dame, Bonavista, Trinity, and Conception) along the northeast coast of Newfoundland and the data do not support the hypothesis of separate “bay stocks”. Annual variation within sampling sites was as large, on average, as the differentiation among sampling sites. The inshore northern cod were distinct from the population in Gilbert Bay and distinct from most offshore northern cod populations. On average, regional differences in allele frequencies were seven times larger than annual variation. The offshore samples were more heterogeneous, and there may be at least three distinct offshore spawning populations of northern cod. In Subdiv. 3Ps, no consistent differentiation was observed among sampling sites, two in inshore bays (Placentia, Fortune), and two in the offshore (Burgeo Bank, Halibut Channel). The southern Grand Bank (Divs. 3NO) may have a separate spawning population from those in other offshore sites, but additional sampling is required to confirm population distinctiveness.
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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".