Comparison of feeding niches between Arctic and northward-moving sub-Arctic marine mammals in Greenland
Bibliographic record
Abstract
The climate change-induced northward movement of sub-Arctic marine mammals increases their range overlap and interactions with native Arctic species. We compared feeding patterns of 11 marine mammal species (4 Arctic and 7 sub-Arctic) in Greenland using stable isotope ratios and fatty acid signatures, and also assessed the effects of lipid extraction on stable isotope ratios. Lipid extraction showed limited increases in δ 13 C, intermediate effects on δ 15 N, and significant depletion of δ 34 S in muscle of some marine mammals. Arctic and sub-Arctic species differed in stable isotope ratios, indicating some use of separate food resources, while likely also reflecting baseline isotopic variation. Proportions of some of the most abundant fatty acids (20:1n9, 22:1n11, 20:5n3, 22:6n3) varied between Arctic and sub-Arctic species, indicating that sub-Arctic species rely mostly on a pelagic food web, while Arctic species exploit an ice-associated and benthic food web, although the sub-Arctic harp and hooded seals and Arctic narwhal showed opposite patterns. Sub-Arctic species had the largest niche breadths, implying diet flexibility and potential to adapt to further changes. Overall patterns in dietary tracers demonstrate separation of feeding niches between most Arctic and sub-Arctic marine mammals, but potential niche overlap and shared food resources for some species. Sub-Arctic seal species overlap the feeding niches of native Arctic species the most of all range-shifters, and of Arctic species, narwhal appear to be the most vulnerable to niche overlap and potential food competition with northward-shifting species.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.004 |
| 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".