Development and Survivorship of Northern Leopard Frogs (Rana pipiens) and Green Frogs (Rana clamitans) Exposed to Contaminants in the Water and Sediments of the St. Lawrence River near Cornwall, Ontario
Bibliographic record
Abstract
Abstract High levels of contamination in the aquatic environment and wildlife within the Ontario portion of the St. Lawrence River at the Cornwall Area of Concern (AOC) have raised questions about potential impacts on wildlife health. Northern leopard frog embryos were raised in two wetland sites within the AOC and at two reference sites to assess differences in water and sediment quality on survivorship and deformity rates. Chlorinated hydrocarbons (total polychlorinated biphenyls, organochlorine pesticides), polycyclic aromatic hydrocarbons, nutrients and heavy metals were measured in sediment and/or water from the study sites. Levels of some metals such as aluminium, cadmium, chromium and copper, exceeded federal and provincial guidelines for the protection of aquatic life, especially in the two AOC wetlands. Early stage tadpole survivorship was significantly lower and deformity frequency significantly higher at wetlands within the AOC; however, differences were likely not biologically significant. Survivorship and deformity rates of leopard frogs (Rana pipiens) at metamorphosis did not differ significantly among sites. Onset of metamorphosis was accelerated in tadpoles raised in wetlands within the AOC. Tadpoles raised in wetlands within the St. Lawrence River AOC took significantly less time to complete metamorphosis (53–55 days) than did tadpoles raised at reference sites (61–64 days). The phenology of metamorphosis was also more synchronous in tadpoles raised in the AOC, with all tadpoles reaching metamorphosis within a space of 3 to 7 days, as compared to 9 to 12 days at reference wetlands; these differences could not be accounted for by water temperature. Differences in development and survivorship rates between AOC and reference sites may be related to contaminant concentrations in water and sediment. However, no strong evidence for beneficial use impairment in terms of reproductive impairments or elevated deformity rates were seen from caged leopard frogs in the two AOC wetlands.
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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 | 0.005 | 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 | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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 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".