Besides being found around the southern tip of South America, Southern Blue Whiting Micromesistius australis is found on the southern shelf of New Zealand, but this is considered to be a distinct sub-species – Micromesistius australis pallidus as opposed to Micromesistius australis australis.

Results from Niklitschek et al. (2009), using genetics and otolith microchemical analyses, are controversial about distinctiveness of two stocks in Atlantic and Pacific oceans. But despite being a highly mobile resource, there is some evidence for sub-population structuring between the Falkland and Chilean areas corresponding to two main spawning grounds and a high level of segregation with both areas (Arkhipkin et al., 2008; Subpesca, 2012b). Based on otolith microchemistry and parasite assemblage approaches, Niklitschek et al. (2010) consider the existence of “at least two ecologically distinct sub-populations of southern blue whiting in South America”. More recently, Leguá et al. (2013) confirm these two stocks according to otolith shape analysis. The present profile focuses on the SW Atlantic biological stock and the assessment unit on Argentinian/Falkland Islands waters presently considered by the National Institute of Fisheries Research and Development (Instituto Nacional de Investigación y Desarrollo Pesquero, INIDEP) for evaluation of the stock and by managers. The SE Pacific stock is covered in another profile.