Patagonian toothfish (Dissostichus eleginoides) are found around South America from Ecuador to Uruguay, and in the sub-Antarctic and Antarctic while Antarctic toothfish (D. mawsoni) are found closer to the Antarctic continental shelf and generally south of the Polar Frontal Zone. Data from existing tagging studies indicate that both species are generally non-migratory with the majority of individuals exhibiting strong site fidelity. Between 2006–2016 there were 111 288 Patagonian toothfish tagged and released of which 10 511 (9.4%) have been recaptured; for Antarctic toothfish there have been 69 067 fish tagged and released of which 2 072 (3.0%) have been recaptured; the median distance between release and recapture was 12km (max 5 708km) and 20km (max 4 525 km) respectively. There were 210 records of Patagonian and 14 Antarctic toothfish where fish had made movements greater than 200km. Of the fish making long-distance movements 91% of D. eleginoides and 86% of D. mawsoni moved in a counter-clockwise direction around Antarctica. The low frequency of long-distance movement of toothfish between management stock units it is unlikely to adversely influence the outcomes of tag-based assessments for toothfish. However, understanding the relative scales of, and interactions between, biological populations and management stock units for toothfish is clearly important element in CCAMLR’s ecosystem-based approach to fisheries management.
[this is an update to WG-FSA-16/25 Rev. 1]