WS-TAG-2023

We review tagging protocol changes made in 2012/13 and provide further recommendations to improve the quality of collected tagging programme data, and conduct research to improve effective tag releases and recoveries. We also provide a tagging training module to inform vessel observers and crew on tagging procedures.

This document summarizes the method used to link releases and recaptures of tagged toothfish and skates in the Convention Area, and the current state of the database of linked tags held by the CCAMLR Secretariat. Thanks to improvements in data quality and the growing use of CCAMLR tags by Members, the quality of links has increased with time. To date, over 98% of recaptured fish have been Read More
Presentado por:
Dr Stephane Thanassekos (Secretaría de la CCRVMA)

Aprobado por:
Dr David Agnew (Secretaría de la CCRVMA)

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Elasmobranchs (sharks, skates and rays) are among the least productive fish species, which make their populations vulnerable to increased mortality. Although skates exhibit elevated vulnerability to fishing, they are commonly caught as incidental bycatch in demersal fisheries. Management measures to prevent the decline of skate populations often Read More
Presentado por:
Ms Johanna Faure

Aprobado por:
Dr Marc Eléaume (Francia)

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Using the simplest form of an abundance estimator using tag-recapture data, the Lincoln-Petersen equation, we summarise the processes that may occur during a tagging program that lead to difficulty in accurately estimating key parameters, and consequently introduce bias into an abundance estimate. We also review the methods that have been used in CCAMLR tag recapture to program to mitigate Read More
Aprobado por:
Ms Doro Forck (Secretaría de la CCRVMA)

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Using a modeling framework for toothfish population dynamics, fishing and data collection, this study investigated how the bias and precision of a CASAL assessment is influenced by various aspects of a tagging program, in particular the effects of the numbers of fish tagged, the duration of a tagging program, the size of tagged fish, and the type of auxiliary data used in the assessment.

Mark-recapture methodologies are commonly used to inform the management of fisheries. In addition to answering targeted research questions, tagging programmes are typically used to describe movement patterns relative to stock unit identification or to support spatial disaggregation of stock assessment areas, and in some instances to derive population abundance estimates. This paper is intended Read More
Aprobado por:
Ms Doro Forck (Secretaría de la CCRVMA)

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CCAMLR Conservation measures currently require vessels to tag only toothfish with a high probability of survival, but no objective criteria are provided for this evaluation. Achieving this requires an objective evaluation of the probability of survival of each fish to be tagged, which in turn requires objective criteria that link observable characteristics to survival. This paper proposes Read More
Aprobado por:
Ms Doro Forck (Secretaría de la CCRVMA)

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With the recognition that CCAMLR tagging programmes are used for abundance estimation of toothfish and skates, tagging operations need to be appropriately supported through documentation, training, and supplies. This paper reviews how tagging programme information could be effectively organised, provides a template training module for observers and vessel crew, and makes recommendations to Read More
Aprobado por:
Ms Doro Forck (Secretaría de la CCRVMA)

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Tagging studies of skates and rays worldwide provide valuable information to help better understand a wide range of metrics including movements and migrations, stock units, growth rates, longevity, discard survival and abundance. Most Antarctic skate species are little known and, coupled with taxonomic and identification problems, this makes the tagging studies undertaken in CCAMLR area a Read More
Aprobado por:
Ms Doro Forck (Secretaría de la CCRVMA)

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A field study is planned to validate the thorn ageing method for Antarctic starry skate (Amblyraja georgiana). This study is a fast, simple ‘add-on’ that will complement the aims of the skate tagging programme. The antibiotic terramycin (oxytetracycline hydrochloride, OTC) will be injected into skates brought into the boat for tagging during the 2019-20 skate tagging programme in the Read More
Presentado por:
Mr Alistair Dunn (Nueva Zelandia)

Aprobado por:
Mr Alistair Dunn (Nueva Zelandia)

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Results from the tagging procedures survey circulated to vessels participating in exploratory fisheries from 2019 to 2020 are presented as background information for WS-TAG-2023. Results suggest that considerable variation in tagging procedures exists among vessels which may impact tagging program performance and also that vessel turnover may influence the level of experience and Read More
Presentado por:
Mr Isaac Forster (Secretaría de la CCRVMA)

Aprobado por:
Dr David Agnew (Secretaría de la CCRVMA)

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Toothfish have been tagged in CCAMLR fisheries since the late 1990’s, and information from the mark-recapture program has been used to estimate movement, growth and mortality rates, and abundance. Tagging of toothfish from fishing vessels in new and exploratory fisheries started in 2000/01, became mandatory in 2003/04, and continues today. This paper provides a Read More
Presentado por:
Dr Christopher Jones (Estados Unidos de América)

Aprobado por:
Dr George Watters

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The conventional tagging information summarized here are comprised of data from the National Marine Fisheries Service’(NMFS), Southeast Fisheries Science Center’s Cooperative Tagging Center (1954-2021), The tagging from The Billfish Foundation, the South Carolina Department of Natural Resources’ Marine Gamefish Tagging Program, the NMFS/Northeast Fisheries Read More
Presentado por:
Mr Derke Snodgrass

Aprobado por:
Dr George Watters

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