Exploratory fishing in Division 58.4.3.a is conducted by two vessels using longlines: “Shinsei Maru No. 3” (Japan) and the “Saint André” (France), since 2012. Precautionary management arrangements are in place in Division 58.4.3.a (Conservation Measures 41-05 and 41-11), while data are collected to provide a robust stock assessment and catch limits. A research plan jointly written by France and Japan has been submitted to WG-SAM-17, which included research objectives, methods and milestones in accordance with Conservation Measure 41-06 and associated measures. The main objective of this paper is to provide an overview of the data collected in Division 58.4.3a up to the CCAMLR fishing season 2016/17.