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Two scales of distribution and biomass of Antarctic krill (Euphausia superba) in the eastern sector of the CCAMLR Division 58.4.2 (55E to 80E)

Citation

Cox, MJ and Macaulay, G and Brasier, MJ and Burns, A and Johnson, OJ and King, R and Maschette, D and Melvin, JE and Smith, AJR and Weldrick, CK and Wotherspoon, S and Kawaguchi, S, Two scales of distribution and biomass of Antarctic krill (Euphausia superba) in the eastern sector of the CCAMLR Division 58.4.2 (55 E to 80 E), PLoS ONE, 17, (8) Article e0271078. ISSN 1932-6203 (2022) [Refereed Article]


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DOI: doi:10.1371/journal.pone.0271078

Abstract

Regular monitoring is an important component of the successful management of pelagic animals of interest to commercial fisheries. Here we provide a biomass estimate for Antarctic krill (Euphausia superba) in the eastern sector of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) Division 58.4.2 (55E to 80E; area = 775,732 km2) using data collected during an acoustic-trawl survey carried out in February and March 2021. Using acoustic data collected in day-time and trawl data, areal biomass density was estimated as 8.3 gm-2 giving a total areal krill biomass of 6.48 million tonnes, with a 28.9% coefficient of variation (CV). The inaccessibility of the East Antarctic makes fisheries-independent surveys of Antarctic krill expensive and time consuming, so we also assessed the efficacy of extrapolating smaller surveys to a wider area. During the large-scale survey a smaller scale survey (centre coordinates -66.28S 63.35E, area = 4,902 km2) was conducted. We examine how representative krill densities from the small-scale (Mawson box) survey were over a latitudinal range by comparing krill densities from the large-scale survey split into latitudinal bands. We found the small scale survey provided a good representation of the statistical distribution of krill densities within its latitudinal band (KS-test, D = 0.048, p-value = 0.98), as well as mean density (t-test p-value = 0.44), but not outside of the band. We recommend further in situ testing of this approach.

Item Details

Item Type:Refereed Article
Keywords:krill, Antarctica, biomass, tempo
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Fisheries sciences
Research Field:Fisheries management
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - wild caught
Objective Field:Wild caught crustaceans (excl. rock lobster and prawns)
UTAS Author:Cox, MJ (Dr Martin Cox)
UTAS Author:Macaulay, G (Dr Gavin Macaulay)
UTAS Author:Brasier, MJ (Dr Madeleine Brasier)
UTAS Author:Johnson, OJ (Ms Olivia Johnson)
UTAS Author:Maschette, D (Mr Dale Maschette)
UTAS Author:Melvin, JE (Miss Jessica Melvin)
UTAS Author:Smith, AJR (Dr Abigail Smith)
UTAS Author:Weldrick, CK (Dr Christine Weldrick)
UTAS Author:Kawaguchi, S (Dr So Kawaguchi)
ID Code:155001
Year Published:2022
Deposited By:Sustainable Marine Research Collaboration
Deposited On:2023-01-23
Last Modified:2023-01-23
Downloads:0

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