Potential Detection and Deterrence Ranges by Harbor Seals of Underwater Acoustic Harassment Devices (AHD) in the Bay of Fundy, Canada
Bibliographic record
Abstract
Abstract.— Underwater acoustic harassment devices (AHDs) are designed to deter seals from attacking fin‐fish aquaculture cages. They may also be unintentionally disturbing non‐target marine mammals. As the distance from the sound source increases, the rate at which the sound pressure level (SPL) drops per unit distance decreases. This prohibits presenting loud sounds near the cages without also creating sounds that can be detected kilometers away. In situ measurements of the sound fields of two AHDs in the Bay of Fundy, Canada, were made. The distances at which a loud AHD with short duration pulses (1.8 msec, 195 dB re 1 μPa at 1 m) and a quieter AHD with longer pulse durations (>50 msec, 166 dB re 1 μPa at 1 m) would be 80 dB or more above the detection threshold of a harbor seal Phoca vitulina were 10 and 3.5 m, respectively. On a quiet day with no nearby vessel traffic, these AHDs would be clearly detectable by harbor seals at ranges up to 2.9 and 1.3 km, respectively. By increasing the pulse length of the louder AHD to >50 msec, the sound would be more than 80 dB above the seal's detection threshold at 100 m but the sound would also be clearly detectable up to 7.2 km. It is technically possible to produce AHDs that are louder. Using very high amplitude sounds to protect finfish aquaculture cages from seal predation without encountering prohibitively large capital and operating costs may not be feasible.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 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 teacher head, 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".