Response of Benthic Diatom Assemblages to Contamination by Metals in a Marine Environment
Bibliographic record
Abstract
Studies on marine benthic diatoms in environments contaminated by metals are scarce. The typical structure of benthic diatom assemblages (species richness, diversity, dominance, dominant taxa) from undisturbed environments may be used as reference for contrasting with contaminated environments in order to observe how said assemblages respond to such disturbance. Thus, the Ho that the structure of benthic diatom associations and morphology of their frustules under contamination by metals would be normal, as in unpolluted environments was tested. To do this, concentrations of 24 metals were surveyed in a coastal zone impacted by mining residues, and the structure of benthic local diatom assemblages was described. Metal concentrations measurements for 15 metals surpassed the normal values of the upper earth cortex, seven were under the low range effect, and three (Cd, Cu, Zn) surpassed the medium range effect values. At a control site no element concentration was above the reference values for low range effect (LRE) or medium range effect (MRE) standards. There, diatom species richness (S) was high, particularly on seaweeds; where, 397 diatom taxa were recorded. In contrast, at the contaminated area 217 diatom taxa were recorded, but diversity (H’) ranged from 2.4 to 4.3. Relative high frequencies of deformed diatom valves mainly of Achnanthes spp. were recorded in contaminated sediments. In general, diatom taxocenoses presented a typical structure for non-contaminated environments. However, scarceness of specimens, lower S, and frequency of deformed valves suggest responses to metal contamination. For marine environments, the latter values corresponding to A. longipes may be considered a reliable reference to the response of benthic diatoms to metal contamination.
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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 | 0.004 | 0.001 |
| 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 | 0.001 |
| 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".