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Towards acoustic monitoring of a mixed demersal fishery based on commercial data: the case of the Northern Demersal Scalefish Fishery (Western Australia)

Citation

Gastauer, S and Scoulding, B and Parsons, M, Towards acoustic monitoring of a mixed demersal fishery based on commercial data: the case of the Northern Demersal Scalefish Fishery (Western Australia), Fisheries Research, 195 pp. 91-104. ISSN 0165-7836 (2017) [Refereed Article]


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PDF (Gastauer, Sven, Ben Scoulding, and Miles Parsons. "Towards acoustic monitoring of a mixed demersal fishery based on commercial data: The case of the Northern Demersal Scalefish Fishery (Western Australia)." Fisheries Research 195 (2017): 91)
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DOI: doi:10.1016/j.fishres.2017.07.008

Abstract

Ongoing monitoring of complex, mixed species environments is a challenging task. In this study, the potential of acoustic and catch data collected aboard a commercial fishing vessel, in combination with geostatistical variance estimates, are explored as a means to derive information on the distribution and abundance of key species groups within selected fishing regions. The FV Carolina M, a trap fishing vessel which operates in waters off Broome, Western Australia, in the Northern Demersal Scalefish Fishery, was equipped with Simrad ES70 echosounders, operated at 38 and 120 kHz. Optical recordings of catch were also obtained, in addition to the acoustic data, during routine fishing operations in 2014. Three regions, where both optical and acoustic datasets were available, were selected for analysis. Geostatistical conditional simulations were used to combine acoustic density information with species composition proportions and length distributions within the catch. For each of the input datasets 250 simulations were conducted, from which individual and combined sampling CVs were derived. Conversion of acoustic densities into abundance estimates was achieved through application of target strength to length relationships (TS-L). Where TS-L was unavailable in the literature for a particular species it was estimated through a Kirchhoff-ray mode model. TS-L equations were estimated for rankin cod (Epinephelus multinotatus)(TSRC = 20 log10(L)  79.6), triggerfish (Balistidae) (TSTF = 20 log10(L)  77.7) and spangled emperor (Lethrinus nebulosus) (TSSE = 20 log10(L)  70.8) at 38 kHz. Sampling error was found to be generally low for catch proportions (<12%) and acoustic densities (<10%). Total sampling error CV for species group abundances within each of the three regions was 9%38%, which is similar to typical estimates reported for acoustic surveys.

Item Details

Item Type:Refereed Article
Keywords:fisheries acoustics, geostatistics, target strength
Research Division:Physical Sciences
Research Group:Classical Physics
Research Field:Acoustics and Acoustical Devices; Waves
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - Wild Caught
Objective Field:Wild Caught Fin Fish (excl. Tuna)
Author:Gastauer, S (Mr Sven Gastauer)
ID Code:120120
Year Published:2017
Deposited By:CRC-Antarctic Climate & Ecosystems
Deposited On:2017-08-10
Last Modified:2017-08-10
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