Occurrence and percent cover of the colonial invasive tunicate Didemnum vexillum from near-seafloor drift transect video imagery and high-resolution digital still images in the western Bay of Fundy, Canada
Bibliographic record
Abstract
Funded under DFO's Marine Conservation Targets Program, this optical imagery benthic survey documents the occurrence and estimated percent cover of the invasive colonial tunicate, Didemnum vexillum in seven drift-camera transects in the 'Head Harbour/West Isles Archipelago/The Passages' Ecologically and Biologically Significant Area (ESBA, ~113km2) in the western Bay of Fundy, New Brunswick, Canada. Occurrence data was derived from the use of high-resolution still images (n=386) taken periodically throughout each transect, and simultaneous continuous high-definition video. Video was divided into 20-second segments (here, we report the start location of each segment within a transect) and when D. vexillum was present in a video segment, frequency of occurrence was classified using a modified SACFOR abundance scale reporting coverage as common (continuous coverage/patches throughout the video segment), occasional (individual colonies of various sizes encountered >5 times throughout the video segment), or rare (small, isolated colonies encountered ≤5 times throughout the video segment). A video segment was deemed unusable and removed from the dataset if there was too much turbidity, or if the camera position was too high off-bottom to reliably image the seafloor. For still images, when D. vexillum was observed in an image, colony percent cover was categorized as >50%, 26-50%, 6-25%, or ≤5% of the images field of view (FOV). Distance travelled and distance between still images (m) was calculated using ArcGIS tools. FOV was estimated by measuring the length and width of a subset of still images and video frame grabs in ImageJ2, using 10-cm lasers for scale. FOV was standardized for each reported altitude, and area sampled (m2) along a continuous video segment was estimated by multiplying the average FOV by the distance travelled in that segment. Didemnum vexillum was found in 44% of the area sampled at depths from 34 to 118m, deeper than previous reports globally of ~80m.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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".