WG-ASAM-2023

Résumé:

In support of ongoing improvements of geospatial operations at the Secretariat, this document presents an update to the approach introduced in document WG-ASAM-2022/02. The intent is to set agreed rules to ensure a standardized approach to the generation of georeferenced objects (e.g. strata polygons) for use in CCAMLR activities. Here, while introducing Read More
Soumis par:
Stephane Thanassekos (Secrétariat de la CCAMLR)

Approuvé par:
David Agnew (Secrétariat de la CCAMLR)

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Résumé:

The implementation of a feedback management system for a sustainable Antarctic krill fishery is challenged by a lack of krill abundance data. Here we present the Krillscan python package to automatically process and share echosounder data from both scientific surveys and fishing operations. This enables an accelerated, transparent, and reproducible analysis of krill backscatter data. We tested Read More
Soumis par:
Sebastian Menze

Approuvé par:
Bjørn Krafft (Norvège)

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Résumé:

In the February 2023 Ukrainian fishing vessel "MORE SODRUZHESTVA" has conducted a local acoustic-trawl survey of Champsocephalus gunnari in the statistical Subarea 48.2. Brief results of this survey are presented here.

Soumis par:
Kostiantyn Demianenko (Ukraine)

Approuvé par:
Kostiantyn Demianenko (Ukraine)

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Résumé:

Antarctic krill (Euphausia superba) are a key species in the Southern Ocean ecosystem, supporting large populations of higher predators, contributing to the sequestration of carbon and the subject of a fishery. Here we detail the deployment and results from 4 years of moored 120 kHz EK80 echosounder data from South Georgia. These data indicate considerable Read More
Soumis par:
Tracey Dornan (Royaume-Uni)

Approuvé par:
Martin Collins (Royaume-Uni)

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Résumé:

At WG-SAM-2022, the Working Group requested further documentation on the acoustic instruments used and the aim of the acoustic component of the Ross Sea shelf survey and suggested presenting the acoustic monitoring plan at WG-ASAM-2023. This paper presents information on acoustic instruments and echosounder settings used by the three New Zealand fishing vessels Read More
Soumis par:
Nathan Walker (Nouvelle-Zélande)

Approuvé par:
Nathan Walker (Nouvelle-Zélande)

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Résumé:

During the austral winter of 2022, three acoustic surveys were carried out to estimate the biomass and distribution of Euphausia superba (Antarctic krill) on the northern shelf of South Georgia. Surveys were undertaken in May, July and September 2022, corresponding with the start, middle and end of the krill fishing season, carried out on board the MV Pharos SG Read More
Soumis par:
Martin Collins (Royaume-Uni)

Approuvé par:
Martin Collins (Royaume-Uni)

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Résumé:

CCAMLRs protocol for calculating krill biomass contains recommendations for procedures to process data collected from acoustic surveys. For instance, only the data collected within the limit of 250 m of the water column are to be included in the calculations. This depth limit was decided assuming that most krill are distributed shallower than this, and Read More
Soumis par:
Guosong Zhang (Norvège)

Approuvé par:
Bjørn Krafft (Norvège)

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Résumé:

Backscatter from metallic spheres is the conventional reference for calibrating the amplitude response of echosounders when used for scientific acoustic biomass estimation. However, these can be time consuming to do, requiring specialized equipment and expertise. A simpler method is desirable when the expertise, equipment, conditions, and time are not available. This work Read More
Soumis par:
Gavin Macaulay

Approuvé par:
Bjørn Krafft (Norvège)

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Résumé:

This paper presents recent developments on the CCAMLR Acoustic Data Repository to firstly provide an overview of raw acoustics data submitted since WG-ASAM-2022 and then outline the data exploration tool created for these data as requested by WG-ASAM-2022. The paper also proposes modifications to the ‘Instruction manual for the collection of fishing-vessel- Read More
Soumis par:
Daphnis De Pooter (Secrétariat de la CCAMLR)

Approuvé par:
David Agnew (Secrétariat de la CCAMLR)

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Soumis par:
Koki Abe (Japon)

Approuvé par:
Takehiro Okuda (Japon)

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Résumé:

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 (55 ̊E to 80 ̊E; area = 775,732 km²) using data collected Read More
Soumis par:
Martin Cox (Australia)

Approuvé par:
Philippe Ziegler (Australia)

Publication:
PLOS ONE, 17(8): e0271078 (2022), doi: https://doi.org/10.1371/journal.pone.0271078

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Résumé:

Total biomass and areal biomass density are often necessary to establish ecological relationships and enable informed management decisions, in particular setting fisheries catch limits. Further refining these estimates to sub-population biomass based on length informs ecological models of predator-prey dynamics, ecosystem energy transfer and biogeochemical cycles; however, measures of Read More
Soumis par:
Martin Cox (Australia)

Approuvé par:
Philippe Ziegler (Australia)

Publication:
Front. Mar. Sci., Sec. Marine Ecosystem Ecology, 10 (2023), doi: 10.3389/fmars.2023.1107567

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Soumis par:
Kazuo Amakasu

Approuvé par:
Takehiro Okuda (Japon)

Publication:
Fish. Sci., 89 (2023): 301–315, doi: https://doi.org/10.1007/s12562-023-01678-6

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Résumé:

Based on the direction of WG-ASAM during 2021, an e-group was established to develop a method to provide estimates of krill biomass for use in the GRYM and for development of a management strategy for krill. Krill biomass densities at a variety of spatial scales are presented for consideration by WG-EMM in 2021. The mean biomass density ranges from a low of 45.54 gm m^-2 for the time Read More
Soumis par:
George Watters

Approuvé par:
George Watters

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