An assessment of the utility of an acoustic Doppler current profiler for biomass estimation
Acoustic Doppler current profilers (ADCPs) are being used increasingly to derive estimates of zooplankton and micronekton abundance. The absence of a practical means for users to perform ADCP calibration, however, makes the quantitative value of this approach questionable. In an attempt to evaluate...
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ftopenunivgb:oai:oro.open.ac.uk:12093 2024-06-23T07:47:50+00:00 An assessment of the utility of an acoustic Doppler current profiler for biomass estimation Brierley, Andrew S. Brandon, Mark A. Watkins, Jonathan L. 1998 https://oro.open.ac.uk/12093/ unknown Brierley, Andrew S.; Brandon, Mark A. <https://oro.open.ac.uk/view/person/mab49.html> and Watkins, Jonathan L. (1998). An assessment of the utility of an acoustic Doppler current profiler for biomass estimation. Deep-Sea Research Part I: Oceanographic Research Papers, 45(9) pp. 1555–1573. Journal Item PeerReviewed 1998 ftopenunivgb 2024-06-05T00:41:20Z Acoustic Doppler current profilers (ADCPs) are being used increasingly to derive estimates of zooplankton and micronekton abundance. The absence of a practical means for users to perform ADCP calibration, however, makes the quantitative value of this approach questionable. In an attempt to evaluate ADCP- derived volume backscattering strength (S-c) data, and hence to assess the utility of such measurements for biomass estimation, a regularly calibrated Simrad EK500 scientific echo-sounder (operating at 38, 120 and 200 kHz) and an RDI narrowband ADCP (153.6 kHz) were similarly configured and run in synchrony on a transect in the Southern Ocean. Data were collected by both instruments from congruent depth (4 m) and time (2 min) bins in order to allow direct comparison of numerous discrete values without the need for further signal averaging. Echoes were recorded from the Antarctic krill, Euphausia super ba, in deep- ocean and on-shelf locations during day and night. ADCP-derived volume back scattering strength data from shallow, evenly distributed krill targets were well correlated with equivalent data from the EK500 (r(2) > 0.98), and the offsets between instruments conformed to those predicted for their respective operating frequencies by a theoretical model of sound scattering by krill (H-0: S-upsilon 153.6 kHz = S-upsilon 120 kHz + 2.3 dB, t(0.05(2),155) = 1.98, t = 0.74, P = 0.46). Data from deeper, more irregularly distributed targets differed significantly (P < 0.001). We conclude that under some ideal, but probably rare, circumstances data from the ADCP can be used to derive biomass estimates. The numerous uncertainties surrounding ADCP calibration and the current practical impossibility for users to monitor system performance should, however, preclude these instruments from being used as a matter of course to determine abundance estimates, a task that we believe should remain firmly within the domain of a well calibrated scientific echo sounder. (C) 1998 Elsevier Science Ltd. All rights reserved. Article in Journal/Newspaper Antarc* Antarctic Antarctic Krill Southern Ocean The Open University: Open Research Online (ORO) Antarctic Southern Ocean The Antarctic Deep Sea Research Part I: Oceanographic Research Papers 45 9 1555 1573 |
institution |
Open Polar |
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The Open University: Open Research Online (ORO) |
op_collection_id |
ftopenunivgb |
language |
unknown |
description |
Acoustic Doppler current profilers (ADCPs) are being used increasingly to derive estimates of zooplankton and micronekton abundance. The absence of a practical means for users to perform ADCP calibration, however, makes the quantitative value of this approach questionable. In an attempt to evaluate ADCP- derived volume backscattering strength (S-c) data, and hence to assess the utility of such measurements for biomass estimation, a regularly calibrated Simrad EK500 scientific echo-sounder (operating at 38, 120 and 200 kHz) and an RDI narrowband ADCP (153.6 kHz) were similarly configured and run in synchrony on a transect in the Southern Ocean. Data were collected by both instruments from congruent depth (4 m) and time (2 min) bins in order to allow direct comparison of numerous discrete values without the need for further signal averaging. Echoes were recorded from the Antarctic krill, Euphausia super ba, in deep- ocean and on-shelf locations during day and night. ADCP-derived volume back scattering strength data from shallow, evenly distributed krill targets were well correlated with equivalent data from the EK500 (r(2) > 0.98), and the offsets between instruments conformed to those predicted for their respective operating frequencies by a theoretical model of sound scattering by krill (H-0: S-upsilon 153.6 kHz = S-upsilon 120 kHz + 2.3 dB, t(0.05(2),155) = 1.98, t = 0.74, P = 0.46). Data from deeper, more irregularly distributed targets differed significantly (P < 0.001). We conclude that under some ideal, but probably rare, circumstances data from the ADCP can be used to derive biomass estimates. The numerous uncertainties surrounding ADCP calibration and the current practical impossibility for users to monitor system performance should, however, preclude these instruments from being used as a matter of course to determine abundance estimates, a task that we believe should remain firmly within the domain of a well calibrated scientific echo sounder. (C) 1998 Elsevier Science Ltd. All rights reserved. |
format |
Article in Journal/Newspaper |
author |
Brierley, Andrew S. Brandon, Mark A. Watkins, Jonathan L. |
spellingShingle |
Brierley, Andrew S. Brandon, Mark A. Watkins, Jonathan L. An assessment of the utility of an acoustic Doppler current profiler for biomass estimation |
author_facet |
Brierley, Andrew S. Brandon, Mark A. Watkins, Jonathan L. |
author_sort |
Brierley, Andrew S. |
title |
An assessment of the utility of an acoustic Doppler current profiler for biomass estimation |
title_short |
An assessment of the utility of an acoustic Doppler current profiler for biomass estimation |
title_full |
An assessment of the utility of an acoustic Doppler current profiler for biomass estimation |
title_fullStr |
An assessment of the utility of an acoustic Doppler current profiler for biomass estimation |
title_full_unstemmed |
An assessment of the utility of an acoustic Doppler current profiler for biomass estimation |
title_sort |
assessment of the utility of an acoustic doppler current profiler for biomass estimation |
publishDate |
1998 |
url |
https://oro.open.ac.uk/12093/ |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Antarctic Krill Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctic Krill Southern Ocean |
op_relation |
Brierley, Andrew S.; Brandon, Mark A. <https://oro.open.ac.uk/view/person/mab49.html> and Watkins, Jonathan L. (1998). An assessment of the utility of an acoustic Doppler current profiler for biomass estimation. Deep-Sea Research Part I: Oceanographic Research Papers, 45(9) pp. 1555–1573. |
container_title |
Deep Sea Research Part I: Oceanographic Research Papers |
container_volume |
45 |
container_issue |
9 |
container_start_page |
1555 |
op_container_end_page |
1573 |
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1802638028694355968 |