Responses of two sentinel species (Hexagenia limbata—mayfly; Pyganodon grandis—bivalve) along spatial cadmium gradients in lakes and rivers in northwestern Québec
Bibliographic record
Abstract
Specimens of the mayfly larva Hexagenia limbata and of the floater mussel Pyganodon grandis were sampled in rivers and lakes contaminated by trace metals in the Abitibi-James Bay region in northwestern Québec. Water samples were collected at each sampling site with in situ diffusion samplers and analyzed for major cations, anions and trace metals (Cd, Cu, Mn, Zn). Surficial sediment samples were also collected at each site and analyzed for Cd, Cu and Zn. In response to Cd contamination at river and lake sites, both sentinel organisms accumulated the metal and synthesized metallothionein (MT), a metal-binding protein synthesized by organisms as a defence mechanism against excess metals in the surrounding media. At the river sites, H. limbata unexpectedly maintained much higher concentrations of MT per unit of accumulated Cd than at the lake sites; this difference between lentic and lotic environments may reflect the response of the species to the more stressful hydrodynamic conditions that prevail in a river. The accumulation of Cd in the mayflies at lake and river sites decreased as a function of the ambient manganese concentration. We hypothesize that dissolved Mn protects against Cd bioaccumulation in H. limbata. The present results support the contention that one cannot extrapolate conclusions drawn from the use of a single sentinel species to a larger set of freshwater invertebrates--both the mayfly and the bivalve are promising biomonitors.
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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 | 0.000 | 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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".