Abstract
Fisheries acoustics surveys provide platforms for deploying passive acoustic equipment to detect cetacean vocalizations. Passive acoustic methods are developing as viable alternatives to visual surveys, particularly for small, inconspicuous species such as the harbour porpoise (Phocoena phocoena). Passive acoustic monitoring using a towed hydrophone array was carried out during an acoustic survey of clupeids in the Clyde Sea and surrounding sea lochs to identify spatial relationships between porpoises and their prey. Methods were developed to process passive acoustic data, successfully identifying porpoise echolocation clicks while discriminating them from the transmitted 120-kHz echosounder pulse and its reflections. To date, this has been a confounding factor which has made these survey techniques potentially incompatible. The highest biomass of pelagic fish was detected in the northernmost parts of the survey region, as were the largest number of porpoises. A moving average was used to examine the scale of the relationships identified, and it was found that while porpoises show no significant preferences for pelagic prey numbers at the smallest scales, they do show significant avoidance of larger areas (5+ km) with very low pelagic fish biomass. This study demonstrates that high-frequency passive acoustic monitoring can be used effectively alongside multifrequency fisheries echosounder surveys to provide novel insights into the trophic interactions between these species, and that further work will hopefully prove useful in improving the efficacy of management strategies for harbour porpoises.
| Original language | English |
|---|---|
| Pages (from-to) | 2075-2084 |
| Number of pages | 10 |
| Journal | ICES Journal of Marine Science |
| Volume | 73 |
| Issue number | 8 |
| Early online date | 23 Feb 2016 |
| DOIs | |
| Publication status | Published - Sep 2016 |
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Keywords
- clupeid
- Clyde
- fisheries acoustics
- harbour porpoise
- passive acoustic monitoring
- predator-prey
- spatial interactions
ASJC Scopus subject areas
- Oceanography
- Ecology, Evolution, Behavior and Systematics
- Ecology
- Aquatic Science
Cite this
Passive and active, predator and prey : Using acoustics to study interactions between cetaceans and forage fish. / Lawrence, Joshua M.; Armstrong, Eric; Gordon, Jonathan; Lusseau, Susan Mærsk; Fernandes, Paul G.
In: ICES Journal of Marine Science, Vol. 73, No. 8, 09.2016, p. 2075-2084.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Passive and active, predator and prey
T2 - Using acoustics to study interactions between cetaceans and forage fish
AU - Lawrence, Joshua M.
AU - Armstrong, Eric
AU - Gordon, Jonathan
AU - Lusseau, Susan Mærsk
AU - Fernandes, Paul G.
N1 - Acknowledgements We thank the skipper and crew of FRV “Alba na Mara” for their work during the cruise which enabled us to carry out our survey work safely and effectively. Thanks are due to the Marine Alliance for Science and Technology Scotland (MASTS) for funding JML's PhD studentship along with the University of Aberdeen. PGF also receives funding from MASTS, which is funded by the Scottish funding council (grant reference HR09011). We are also indebted to Doug Gillespie and the development team at PAMGuard for their software without which little of the passive acoustic data processing would have been possible, and the R Development Core Team for maintaining the software used for data analysis. We also thank the anonymous reviewer whose helpful comments led to significant improvements of the paper.
PY - 2016/9
Y1 - 2016/9
N2 - Fisheries acoustics surveys provide platforms for deploying passive acoustic equipment to detect cetacean vocalizations. Passive acoustic methods are developing as viable alternatives to visual surveys, particularly for small, inconspicuous species such as the harbour porpoise (Phocoena phocoena). Passive acoustic monitoring using a towed hydrophone array was carried out during an acoustic survey of clupeids in the Clyde Sea and surrounding sea lochs to identify spatial relationships between porpoises and their prey. Methods were developed to process passive acoustic data, successfully identifying porpoise echolocation clicks while discriminating them from the transmitted 120-kHz echosounder pulse and its reflections. To date, this has been a confounding factor which has made these survey techniques potentially incompatible. The highest biomass of pelagic fish was detected in the northernmost parts of the survey region, as were the largest number of porpoises. A moving average was used to examine the scale of the relationships identified, and it was found that while porpoises show no significant preferences for pelagic prey numbers at the smallest scales, they do show significant avoidance of larger areas (5+ km) with very low pelagic fish biomass. This study demonstrates that high-frequency passive acoustic monitoring can be used effectively alongside multifrequency fisheries echosounder surveys to provide novel insights into the trophic interactions between these species, and that further work will hopefully prove useful in improving the efficacy of management strategies for harbour porpoises.
AB - Fisheries acoustics surveys provide platforms for deploying passive acoustic equipment to detect cetacean vocalizations. Passive acoustic methods are developing as viable alternatives to visual surveys, particularly for small, inconspicuous species such as the harbour porpoise (Phocoena phocoena). Passive acoustic monitoring using a towed hydrophone array was carried out during an acoustic survey of clupeids in the Clyde Sea and surrounding sea lochs to identify spatial relationships between porpoises and their prey. Methods were developed to process passive acoustic data, successfully identifying porpoise echolocation clicks while discriminating them from the transmitted 120-kHz echosounder pulse and its reflections. To date, this has been a confounding factor which has made these survey techniques potentially incompatible. The highest biomass of pelagic fish was detected in the northernmost parts of the survey region, as were the largest number of porpoises. A moving average was used to examine the scale of the relationships identified, and it was found that while porpoises show no significant preferences for pelagic prey numbers at the smallest scales, they do show significant avoidance of larger areas (5+ km) with very low pelagic fish biomass. This study demonstrates that high-frequency passive acoustic monitoring can be used effectively alongside multifrequency fisheries echosounder surveys to provide novel insights into the trophic interactions between these species, and that further work will hopefully prove useful in improving the efficacy of management strategies for harbour porpoises.
KW - clupeid
KW - Clyde
KW - fisheries acoustics
KW - harbour porpoise
KW - passive acoustic monitoring
KW - predator-prey
KW - spatial interactions
UR - http://www.scopus.com/inward/record.url?scp=84990924232&partnerID=8YFLogxK
U2 - 10.1093/icesjms/fsw013
DO - 10.1093/icesjms/fsw013
M3 - Article
VL - 73
SP - 2075
EP - 2084
JO - ICES Journal of Marine Science
JF - ICES Journal of Marine Science
SN - 1054-3139
IS - 8
ER -