The history of commercial freshwater mussel harvest in southern Ontario: a short-lived fishery with long-lasting consequences
Bibliographic record
Abstract
Freshwater mussels (Bivalvia: Unionidae) have long been an important aquatic resource for humans, and North America’sIndigenous nations have harvested them for over 10 000 years. European exploitation began in the latter half of the 19th century, initially focussing on the collection of pearls and later shifting to the manufacture of buttons at the onset of the 20th century. By 1911, Canadian pearl button factories operated in Windsor, Berlin (now Kitchener), and Trenton, Ontario, and, by 1921, Ontario shell was being exported to factories in the United States. The Canadian harvest did not last long and ended by the mid-1940s as resources dwindled because of overexploitation, pollution, and industrial shifts to other raw materials for buttons (e.g., plastics). Annual river-specific harvest ranged from ~ 66 to 110 tonnes with a maximum of 291 tonnes (~1.1–4.4 million animals) collected at Dunnville on the lower Grand River in 1915. Although detailed collection information is lacking, species such as Mucket (Actinonaias ligamentina), Threeridge (Amblema plicata), and Round Pigtoe (Pleurobema sintoxia, now listed federally as Endangered) were targetted, while Purple Wartyback (Cyclonaias tuberculata, also now Endangered) was discarded (i.e., killed). Commercial harvests typically targetted adults, because they provided the desired quantity and type of material, resulting in death. Recent studies have shown that this type of directed mortality can have the greatest impact on the long-term persistence of these populations and, although the specific impacts of the historical harvest cannot be determined, it is likely that these harvests contributed to the current state of imperilment of this fauna.
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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.006 | 0.003 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 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".