CCAMLR

The multi-year variability of the Patagonian toothfish (Dissostichus eleginoides) size composition in longline catches in the South Georgia maritime zone   in context of  the fishery  management is discussed.

The quality of observer’s data is obviously a very important point to produce the best advices on fishery management. This paper presents the use of an application on smart phone to help observers memorizing species name.

Data collection at sea is based on forms provided by CCAMLR. This paper provides  proposals for future changes in the skipper’s forms to be considered by the working group.

The key issues for development of krill fishery management schemes based on the ecosystem approach and proposal to generate baseline data in the context of addressing these problems are considered.

In this paper, we report on fish by-catch during exploratory fishing activities undertaken in Divisions 58.4.1 and 58.4.2 during the 2012 to 2018 seasons. Fish by-catch comprised 14 species or groups of species. In 2018, by-catch represented 12% of the total catch (43 tonnes over 307 tonnes of Dissostichus spp.) in Divisions 58.4.1 and 58.4.2. 98% of the biomass was represented by 2 families: Macrouridae and Channichthyidae. The others most common by-catch species or families were Muraenolepis spp., Antimora rostrata and Artedidraconidae. Raja and Bathyraja were rarely caught. Species composition varied between research blocks except for Macrourus spp. which dominated by-catch composition everywhere. The ratio by-catch to target catch was higher in the eastern part of Division 58.4.1. The ratio Macrourus to Dissostichus increased in every research blocks during the study period, particularly in the eastern blocks where Macrourus CPUE also increased in the last 3 years. Macrourus CPUE was 23kg/1000 hooks in average with relatively little spatial variations except in the east were it could reach 180kg/1000 hooks locally. As found in others areas of the Convention, Macrourus CPUE was 2 times higher for autolines than Spanish lines and trotlines, and it peaked at depths between 900 and 1300m. CPUE distribution of the others by-catch species were much lower and highly heterogeneous in space. Macrourus catch was dominated by females in all research blocks and length frequency distribution did not reveal any temporal changes within research blocks. Length at 50% maturity was estimated for the two most common species of Macrourus (Macrourus whitoni and Macrourus caml) and for Chionobathyscus dewitti. 95% of the Muraenolepis sp. and Antimora rostrata were females in every research blocks with spatial variations in total length frequency distribution.

Fishing vessels using ~10 km long bottom longline operate in the French EEZ of Kerguelen and Crozet and report catches by species along with geographical coordinates. This papers presents a new method to better take into account the information associated to the path of the line instead of only the mid-point as commonly used to calculate catch rates.

Skates are frequently caught as by-catch during commercial longline fishing operations within CCAMLR subareas 48.3 and 48.4. Morphological evaluations of the by-catch in these subareas indicate that up to three species from the skate genus Amblyraja occur: A. georgiana, A. georgiana sp. anon and Amblyraja taaf. In this report, we present results from the first population genetic analysis of these Amblyraja skates to assess if their current morphological classification during by-catch assessment reflects potential genetic discontinuities. Our results reveal that it is sampling location (geography), rather than morphology, that is the major determinant of population differentiation in these Southern Ocean skates.