ASSESSING THE EXTENT OF HYBRIDIZATION BETWEEN WESTSLOPE CUTTHROAT TROUT AND INTRODUCED RAINBOW TROUT IN THE UPPER KOOTENAY RIVER, BRITISH COLUMBIA
Bibliographic record
Abstract
Many westslope cutthroat trout (WCT) populations in the United States of America (USA) are threatened by hybridization with non-native trout. However, less is known about the genetic status of WCT populations in Canadian portion of their range. The Upper Kootenay River in British Columbia (BC) was considered a stronghold for WCT, but a preliminary study conducted from 1999 to 2001 found evidence of recent hybridization likely caused by stocking introduced rainbow trout (RBT, Oncorhynchus mykiss) in the Koocanusa Reservoir in the late 1980s. We assessed the distribution of native WCT, RBT, and their hybrids in the Upper Kootenay River using seven co-dominant, simple sequence repeat markers, and the program NEWHYBRIDS Version 1.1 beta. We determined the genotypes of 2,670 fish collected from 31 different streams between 1999 and 2006. Most fish were classified as pure WCT (85%), whereas pure RBT, RBT backcross and F1 individuals were rare (combined 2.8%). However, a broad hybrid zone stretching over 200 km was observed with WCT backcross individuals as the dominant hybrid type present (6%). Sites with no fish migration barriers between them and the Koocanusa Reservoir (open sites) had significantly more hybrid genotypes than sites isolated above migration barriers 36 (closed sites; X = 60.15, df = 5, p < 0.00001). Open sites < 90 km from the reservoir had more RBT, RBT backcross, and F1 types than sites further from the reservoir, and hybrids appear to be the main vector for the dispersal of RBT alleles to upstream sites. The hybrid zone appears to be limited by environmentally dependent factors (ecotone model). Management efforts should focus on identifying and limiting the sources of RBT in the watershed, identifying the remaining pure WCT populations, and learning more about the movement of WCT within the hybrid zone.
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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) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.002 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.005 | 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".