Evidence for Three Morphs of Arctic Char (Salvelinus alpinus) Present in the Marine Environment Off the Coast of Ulukhaktok, Northwest Territories, Canada
Bibliographic record
Abstract
Alternative resource use and responses to environmental conditions can lead to phenotypic diversity and distinct morphotypes within many anadromous salmonids, including arctic char. Arctic char is a culturally and economically important subsistence resource in the Inuvialuit Settlement Region (ISR).The current study examined char’s morphological plasticity during their summer marine migration where local harvesters have noticed a decrease in small sized individuals, but where limited knowledge exists on char morphology and population mixing in the area. Morphometric analysis was conducted using digital photographs taken of live arctic char collected during marine migration-residency along the Ulukhaktok coast. Twenty-three landmarks were placed on digital images of 103 fish and used to investigate the presence of different morphotypes, followed by PCA and K-means analyses. The results categorized fish into three clusters based on distinctions in head and body shape; slender body and slim head (n=31), small and short head with a small mouth (n=46), elongated head shape with large mouth (n=26). These three morphs likely represent adaptation to specific feeding—movement behaviours, correlated with unique origin lakes. This study represents the first to identify arctic char morphs in the marine environment and identifies overlap in their habitat use during the marine phase with implications for differential resource extraction. The derived information can inform fisheries management in the ISR and Ulukhaktok on likelihood of overfishing specific phenotypes that could potentially reduce stock diversity, ensuring long term sustainability of the fishery.
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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 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| 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".