Detection probability and density estimation of fin whales by a Seaglider
A single-hydrophone ocean glider was deployed within a cabled hydrophone array to demonstrate a framework for estimating population density of fin whales ( Balaenoptera physalus ) from a passive acoustic glider. The array was used to estimate tracks of acoustically active whales. These tracks became...
| Published in: | The Journal of the Acoustical Society of America |
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| Main Authors: | , , , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
2022
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| Subjects: | |
| Online Access: | https://research-portal.st-andrews.ac.uk/en/researchoutput/detection-probability-and-density-estimation-of-fin-whales-by-a-seaglider(386a64f1-7451-4fd4-83d9-bf9caf339988).html https://doi.org/10.1121/10.0014793 https://research-repository.st-andrews.ac.uk/bitstream/10023/27449/1/Fregosi_2022_JASA_Detection_probability_VoR.pdf |
| Summary: | A single-hydrophone ocean glider was deployed within a cabled hydrophone array to demonstrate a framework for estimating population density of fin whales ( Balaenoptera physalus ) from a passive acoustic glider. The array was used to estimate tracks of acoustically active whales. These tracks became detection trials to model the detection function for glider-recorded 360-s windows containing fin whale 20-Hz pulses using a generalized additive model. Detection probability was dependent on both horizontal distance and low-frequency glider flow noise. At the median 40-Hz spectral level of 97 dB re 1 μPa 2 /Hz, detection probability was near one at horizontal distance zero with an effective detection radius of 17.1 km [coefficient of variation (CV) = 0.13]. Using estimates of acoustic availability and acoustically active group size from tagged and tracked fin whales, respectively, density of fin whales was estimated as 1.8 whales per 1000 km 2 (CV = 0.55). A plot sampling density estimate for the same area and time, estimated from array data alone, was 1.3 whales per 1000 km 2 (CV = 0.51). While the presented density estimates are from a small demonstration experiment and should be used with caution, the framework presented here advances our understanding of the potential use of gliders for cetacean density estimation. |
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