DIET OF HARP SEALS (<i>PAGOPHILUS GROENLANDICUS</i>) IN NEARSHORE NORTHEAST NEWFOUNDLAND: INFERENCES FROM STABLE‐CARBON (δ<sup>13</sup>C) AND NITROGEN (δ<sup>15</sup>N) ISOTOPE ANALYSES
Bibliographic record
Abstract
Abstract Trophic position, and often the source of feeding of predators in food webs, can be estimated using measurements of stable isotope ratios of nitrogen and carbon in predators and their prey. Muscle samples from 60 harp seals (Pagophilus groenlandicus) collected during May 1995 in nearshore waters of New foundland, Canada, were analyzed for δ13C and δ15N values. These values were compared with those for 63 prey samples representing seven species generally collected near the same area. Using diet‐tissue isotopic fractionation factors derived from previous studies using captive animals, we infer a greater dependence of harp seals on lower trophic‐level prey during April compared with results expected from exclusive diets of Atlantic cod (Gadus morhua), Atlantic herring (Clupea harengus), Greenland halibut (Reinhardtius hippoglossoides), or northern shrimp (Pandalus borealis). Our mean δ15N value for harp seals is lower than previous findings for seals collected on the winter whelping patch and may be a function of interannual or seasonal differences in diet. Subadult seals (aged 1‐4 yr) had significantly lower δ15N values than adults (5 + yr), suggesting that older seals were feeding at a slightly higher trophic level.
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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 | 0.000 | 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".