Harbour porpoise hydrophone array data recorded on a gill net ...
Entanglement in net fisheries (static and drift) is the largest known cause of direct anthropogenic mortality to many small cetacean species, including harbour porpoise (Phocoena phocoena), in UK waters. Despite this, little is known about the behaviour of small cetaceans in proximity to nets. We ha...
| Main Authors: | , , , , , |
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| Format: | Dataset |
| Language: | English |
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Dryad
2022
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.5061/dryad.v9s4mw6xv https://datadryad.org/stash/dataset/doi:10.5061/dryad.v9s4mw6xv |
| Summary: | Entanglement in net fisheries (static and drift) is the largest known cause of direct anthropogenic mortality to many small cetacean species, including harbour porpoise (Phocoena phocoena), in UK waters. Despite this, little is known about the behaviour of small cetaceans in proximity to nets. We have developed a passive acoustic monitoring (PAM) system for tracking the fine scale three-dimensional (3D) movements of echolocating cetaceans around actively fishing nets by localising their acoustic clicks. The system consists of two compact four-channel acoustic recorders with sample-synchronised sensor packages that use 3D motion tracking technology to accurately log orientation, depth, water temperature and ambient light level. Two recorders were used in tandem, with each one attached to and floating above the net float-line. The system can be deployed during normal fishing operations by a trained researcher or experienced fisheries observer. Recordings were analysed in PAMGuard software and the 3D positions ... : These data are processed acoustic recordings from two acoustic devices recording on an actively fishing gill net. The aim of the study was to try and acquire detailed 3D behavioural information on harbour porpoises around gill nets via acoustic localisation. Each recorder contained a micro-aperture 4 element hydrophone array and accurate depth and orientation sensors. The 4-channel array within each device allowed for a relative 3D vector to a received harbour porpoise echolocation click to be calculated. Depth and orientation sensor then allowed the vector to be geo-referenced (i.e., relative to north). The two recorders were separated by 15- 40m along the headline of the gill net – if two devices detected the same click then the location of the harbour porpoise was the point at which the two resulting vectors crossed. As porpoises (and dolphins) echolocate regularly, localising successive clicks allowed a 3D track of an animal to be constructed over time, providing detailed information on animal movements ... |
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