Quantifying Elements in Arctic Grayling and Bull Trout in the South Nahanni River Watershed, Northwest Territories, Using Nonlethal Tissue Samples
Bibliographic record
Abstract
Abstract Monitoring of contaminants in fish generally involves lethal sampling, but public scrutiny and increased pressure on fisheries have driven the need to develop nonlethal sampling methods. We examined the ability of adipose, anal, and caudal fin tissues to serve as nonlethal surrogates for lethal muscle tissue samples in the analysis of metals (elements). First, we evaluated the use of biopsies by examining relationships between concentrations of 39 elements in low-volume dorsal muscle biopsies and high-volume muscle samples from Arctic Grayling Thymallus arcticus and Bull Trout Salvelinus confluentus collected in the South Nahanni River watershed, Northwest Territories, Canada. Low-volume dorsal biopsy samples in this study served to most closely model the concentrations of elements found in high-volume dorsal samples; caudal and anal fins were more representative of high-volume dorsal samples than were adipose fins. Regressions between high- and low-volume dorsal muscle samples were significant for 12 elements/species, with Cs, Rb, and Tl having the strongest relationships in both species. Regression analyses comparing low-volume muscle samples and fin samples revealed variation between Arctic Grayling and Bull Trout, but Co, Hg, and Tl concentrations among samples were strongly related for both species. Addition of fish length or age as a covariate did not greatly improve the predictive power of calculated regressions. For future monitoring, selection of a nonlethal sampling strategy (e.g., use of dorsal biopsy or adipose fin samples) will require consideration of the element of interest, the primary route of exposure, interaction with other elements, and the basic biology and ecology of the fish species. Ideally, nonlethal sampling tools can be further developed for the two species to promote inclusion of community partners; these tools offer sustainable, long-term approaches for monitoring sensitive fish populations in northern Canadian habitats. Received February 29, 2016; accepted September 9, 2016Published online December 20, 2016
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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 | 0.001 | 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".