Assessment of heavy metal contamination in Halifax harbour using mussel and tunicate biomonitors and diffusive gradients in thin films
Bibliographic record
Abstract
This study reports on levels of measurable trace metals in Halifax Harbour, Nova Scotia, in water samples, tissues of biomonitor species, and diffusive gradients in thin films (DGTs) – an in situ passive sampling device. Vase tunicates, Ciona intestinalis and blue mussels, Mytilus edulis, were selected as biomonitor species. The water, DGT, and tissue samples were collected from four sites in Halifax Harbour at five to six week intervals from June to October 2008. Mussels were collected from wharfs at two sites, and tunicates from the sites of DGT placement. In October 2008, tunicate samples from six smaller harbours in Nova Scotia were obtained for comparison of trace element content. All samples were analysed by inductively coupled plasma – mass spectrometry for determination of Mn, Mo, Cu, U, As, Co, Cd, Pb, and Ni concentrations. Halifax Harbour trace metal concentrations were established by complementary data from water samples (Mn, Mo, Cu, U, and U) and DGT samples (Co, Cd, Pb, and Ni). The data indicated a few significant localized variations and several temporal variations in the water column concentrations of some metals which, in the case of Mn and Cu, were attributed to storm drain effluents and rainfall events. Mytilus edulis bioaccumulated Co, Ni, Cu, Mo, Cd, and As to a greater extent than Ciona intestinalis, which accumulated higher concentrations of V. Bioconcentration factors for both biomonitor species indicate greater tissue concentrating capacity for Mn (800-4000), Cu (800-2000) and As (400-900), compared to Mo (40-75) and U (30-55). Concentration factors were similar in the two biomonitor species and, for M. edulis, appeared to increase with size. C. intestinalis in Halifax Harbour had among the lowest concentrations of As, Pb, Co, and Cu when compared to C. intestinalis in small harbours around Nova Scotia, possibly due to the placement of plate collectors at a greater distance from shore influences in Halifax Harbour.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 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 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".