Using Nucella lapillus (L.) as a bioindicator of tributyltin (TBT) pollution in eastern Canada: a historical perspective
Bibliographic record
Abstract
Dogwhelks (Nucella lapillus), a universal bioindicator of tributyltin (TBT) pollution, were used to determine butyltin distribution in three Atlantic Canada harbours previously surveyed between 1995 and 2006. N. lapillus were analysed for the presence of TBT and its degradative products while imposex incidence and severity were compared with previous surveys to assess the efficacy of the Canadian regulations on TBT. Imposex was observed at two harbours that had dogwhelks, but not at surrounding reference sites. When comparing results with previous surveys in the same geographic area, there appears to be some improvement of affected N. lapillus populations, suggesting that the 1989 Canadian regulations have been effective in decreasing imposex severity for most sites as measured by the vas deferens sequence index (VDSI), but not the occurrence of imposex. The highest butyltin tissue concentration (63.75 ng Sn g−1, dry wt) was detected in imposex-affected females from Red Head in Saint John Harbour (New Brunswick), which is adjacent to an area frequented by large oil tankers that, under the 1989 regulations, are legally allowed to use TBT antifouling paint. This study is the first to illustrate a significant correlation between TBT levels and imposex on a spatial scale in Atlantic Canada.
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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 | 0.002 | 0.002 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 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".