Fatty acids and stable isotopes (δ<sup>13</sup>C and δ<sup>15</sup>N) reveal temporal changes in narwhal (<i>Monodon monoceros</i>) diet linked to migration patterns
Bibliographic record
Abstract
Abstract Narwhals ( Monodon monoceros ) are sentinel species in the Arctic and to investigate marine food web changes from 1982–2011 we examined diet using fatty acids, δ 15 N, and δ 13 C, in narwhals from Baffin Bay ( BB ) and northern Hudson Bay ( NHB ). We predicted temporal changes would be greater in NHB due to a significant reduction in summer ice cover. In NHB , δ 15 N significantly increased, δ 13 C displayed a parabolic trend, and fatty acids gradually shifted, albeit not significantly, over time. δ 15 N was stable, δ 13 C decreased, and fatty acids significantly changed over time in BB . Stable isotope mixing models indicated a dietary reduction in capelin and increase in Greenland halibut from 1994–2000 to 2006–2011 in BB , while capelin was an important dietary component for narwhals in NHB in recent years (2006–2011). These dietary changes may be attributed to changes in sea ice and narwhal migration. Seasonal dietary changes, as evidenced by changes in blubber fatty acids and skin and muscle stable isotopes, were not as apparent in the NHB population, which may be indicative of a reduced migratory distance. Long‐term monitoring of narwhal diet and migratory patterns associated with reduced sea ice provides invaluable information about how the marine ecosystem will redistribute with global warming.
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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 | 0.002 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.002 |
| 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 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".