Dynamics of indigenous rock crab (Cancer irroratus) and invasive Green Crab (Carcinus maenas) populations during invasion of a southern Newfoundland estuary
Bibliographic record
Abstract
Little literature exists on green crab (Carcinus maenas) and particularly rock crab (Cancer irroratus) in Newfoundland (Canada) waters. In this study, we document demographic composition for the two species upon invasion of green crab into the North Harbour, St. Mary’s Bay, estuary, an area previously only occupied by rock crab and undergoing progressive warming. Using data collected via a citizens science approach, we address objectives of documenting the rate of change in speciation upon green crab invasion in the estuary and providing novel data on basic life history processes for rock crab and green crab in Newfoundland waters. The study shows a rapid proportional switch in species composition in the estuary upon green crab invasion, with green crab increasing from a proportion of 0 to 0.75 of collected samples within three years of being detected. Novel data on rock crab suggest overall consistencies with life history processes as described in the broader literature, including presence of molting periods centred near May and August, a shallow water mating migration in fall, and a similar size-at-instar structure as crab along the eastern United States. Novel data on green crab biology suggests the St. Mary’s Bay population has similar life history attributes as the original invading population in Newfoundland, including spring-summer spawning and an inferred paucity of molting in fall. Allometric carapace relationships of the North Harbour green crab are the same as those described in the Pacific and northeast Atlantic oceans. The size structure of green crab in the North Harbour estuary has broadened in the three years since initial detection with increased presence of large crab beyond the supposed size-at-maturity in recent years.
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 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| 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".