American Eel (Anguilla rostrata) freshwater population trajectory in Canada
Bibliographic record
Abstract
Describing trends in American Eel (Anguilla rostrata) abundances has been tackled regularly at various locations across its range; however, describing a common trajectory for the whole panmictic population has been a challenge. As a step toward this broader challenge, 12 fishery-independent datasets from freshwater across the Canadian range were used to estimate a Canada-wide trajectory of American Eel relative abundance. These datasets averaged 29 years per time series (range: 14-65) over the 1952-2018 time period. Time series mostly tracked yellow eel (n = 10), with some elver (n = 1) and silver eel (n = 1). Each dataset was standardized to control for potentially confounding factors, and the standardized statistical models were used to generate a standardized time series of relative abundance. These standardized relative abundances were transformed to a common scale, and a Canada-wide trend was fit. Generally, datasets with more historical data had more negative year trends. The Canada-wide trend produced mean rates of decline of -0.021 to -0.046 per year since 1980. The model indicated a 100% likelihood that the Canadian freshwater population has declined since 1980 and a 69.2-100% likelihood that the decline was greater than 50%. Limiting data to the 2000-2018 years produced less negative trends that generally did not differ from zero. Results were robust to the data standardizations, inclusion or exclusion of individual datasets, and adjustments for the spatial distribution of data. Overall, this analysis shows that while American Eel freshwater abundance in Canada has been stable over the last two decades, significant declines preceded this time period and were not limited to the St. Lawrence basin.
Stored with the screening record, where it is evidence for the labels above.
How this classification was reachedexpand
The three-model screen
all 5,600 screened works →All three models called this out of scope.
Fisheries science estimating American Eel abundance trends across Canada.
This analyzes Canadian American eel population trends rather than the Canadian research system.
Ecology/conservation trend analysis of American eel abundance, not research practice.
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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.004 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| 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".