Conversion Factors used for Patagonian toothfish in Division 58.5.1. and Subarea 58.6

Conversion Factor is a crucial value used to calculate green weight using product weight and thus assess the amount of fish withdrawn from the stock. This paper describes factors influencing conversion factor using data collected on Patagonian toothfish within the French EEZ, results emphasise the need to calculate CF with a sub-sample of the catch that is representative of the total catch in terms of size, space and time. It also looks at the size of sub-sample used for conversion factor measurement in relation with the accuracy of weight estimated at sea.