A Field Experiment To Determine the Relative Importance of Prey and Water as Sources of As, Cd, Co, Cu, Pb, and Zn for the Aquatic Invertebrate <i>Sialis velata</i>
Bibliographic record
Abstract
We measured the relative importance of water and food as sources of the trace elements As, Cd, Co, Cu, Pb, and Zn for larvae of the benthic insect Sialis velata. To achieve this end, we first exposed its prey, the midge Chironomus riparius, to trace elements in a contaminated lake located near a nonferrous metal smelter in northwestern Quebec. Concentrations of five of the six trace elements reached a steady state in prey within one week. When predators were exposed to these contaminated prey, their trace element concentrations increased markedly for all of the trace elements studied. In contrast, exposure of S. velata to contaminated lake water led to no significant increase in their concentrations of five of the six trace elements ([Pb] increased only slightly). Additional treatments in which the predator was exposed to these trace elements in both food and water or in a combination of food and water and sediment did not lead to further increases in its contaminant concentrations beyond those measured in the food-only treatment. We conclude that food (prey) is the almost exclusive source of As, Cd, Co, Cu, and Zn for S. velata and that it is the source of 94% of its Pb. Model curves for trace element accumulation over time by the predator fit our measured data well, and trace element concentrations in food alone are sufficient to model the exchange of these contaminants in this insect.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".