Sampling methods to determine the composition and nature of the catch of the longlining fishery around CCAMLR Subarea 48.3 have, to date, been limited to in situ line observations conducted by CCAMLR observers deployed on the fishing fleet. The collection of this data is important for the assessment and management of the fishery. This independent estimation of the total catch in the fishery requires considerable effort and cost with mixed results. For example it is not always possible to achieve a reasonable figure/rate of line observation for each setting of the lines. A video recording system was installed on a longliner targeting toothfish in CCAMLR Subarea 48.3. This system provided 100% of coverage of all setting and hauling activities on this vessel. It proved to be reliable, easy to set up by the observer/crew and does not require structural modifications on the vessel. Fishing events were divided in settings and hauling operations where at-sea observations were matched with video footage recorded then divided into sessions termed ‘slots’. During settings, 284,800 hooks distributed in 31 slots totalling 31 hours and 57 minutes were observed and recorded. For hauling, a total of 53,403 hooks were randomly selected and observed at sea. The total amount of video footage recorded during these observations was 40 hours and 42 minutes, divided into 62 slots. Data gathered from at-sea observations conducted by a scientific observer was compared with recorded video footage recorded by 3 different video reviewers watching the video footage. No significant differences were found in the number of all species of vertebrate counted in situ and in the video footage by the different video reviewers (observers). However catch composition for invertebrates showed high discrepancy between in situ and footage observations.
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Doug Cooper (Secrétariat de la CCAMLR)
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