Trophic Structure and the Isotopic Niche Dynamics of the Tasiujaq (Eclipse Sound, Nunavut, Canada) Marine Food Web
Bibliographic record
Abstract
ABSTRACT Rapid warming in the Arctic is causing cumulative impacts on ecosystems, including widespread reduction in sea ice extent, resulting in shifts in primary production, which can have cascading bottom‐up trophic influences on marine food web structure and function. Understanding trophic interactions and the structure of local food webs across the Canadian Arctic remains fragmented, yet it is essential to inform conservation efforts and provide a comparative reference to assess future food web shifts driven by climate change. We used stable isotope analysis (δ13C and δ15N) to determine the isotopic niche dynamics (e.g., size and overlap) and trophic positions among invertebrates, fishes and marine mammals sampled from 2015 to 2019 to quantify the trophic interactions and trophic structure of the Eclipse Sound food web. Mean trophic positions ranged from 2.0 for copepods to 4.4 for sea tadpoles, with some individuals, such as narwhal and ringed seals, occupying a trophic position of 5.3, indicating a marine food web that spans at least four trophic levels. Across taxonomic groups, isotopic niche size was largest in the invertebrate taxonomic group (7.87‰2), followed by fishes (3.26‰2) and then marine mammals (2.03‰2). The core isotopic niche overlap between taxonomic groups ranged from no overlap between invertebrates and fishes, or between marine mammals and invertebrates and 44% overlap between fishes and marine mammals. Overall, we present the marine food web structure of over 50 species of invertebrates, fish and mammals during the open‐water period in Eclipse Sound, Nunavut, and provide a reference point for future assessments of food web dynamics and conservation goals.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".