Bibliographic record
Abstract
Increasing release of mercury (Hg) through gold amalgamation, and deforestation have been major concerns in South America. Volcanic sources have also contributed to the natural emission of Hg from the Andes Mountains. Hg not only exhibits biomagnification through aquatic food webs, but it is also neurotoxic and impacts the reproductive capacity of fish. Many studies have assessed Hg biomagnification from areas of gold mining and erosion, but ours is one of the first to examine Hg contamination in a relatively undisturbed area. We used stable nitrogen () and carbon (13C) isotopes to characterize the food web of Río Las Marías, Venezuela, and examine Hg biomagnification trends. Representative fish species from Río Las Marías were collected during January‐February 2004, including detritivores, herbivores, invertivores, parasites, piscivores, and carnivores. Nitrogen isotope results indicate that parasitic catfish (Ochmancanthus alternus) ( = 12.2‰), carnivorous stingrays (Potamotrygon orbignyi) ( =11.4‰) and piscivorous redeye piranhas (Serrasalmus rhombeus) ( =10.9‰) act as top consumers in the web. Detritivorous characins (Steindachnerina argentae) (=6.8‰), and invertivorous knifefish (Apteronotus albifrons) ( =7.9‰) were located at the bottom of the food web. Although the highest value was observed from Ochmancanthus alternus due to its unusual diet of fish mucus, we predict that piscivorous species will exhibit higher Hg concentrations by consuming the muscle tissue where Hg is stored. Our assessment of Hg patterns in Río Las Marías will clarify the extent of Hg contamination in undisturbed areas, and will offer a valuable comparison to rivers that are influenced by gold mining activities.3
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 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) | 0.001 | 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".