Patagonian toothfish Dissostichus eleginoides occurs in the Southern Ocean and on the South American Plateau. Several stock identification methods suggest the existence of at least four biological stock units within the wide Patagonian toothfish’s distribution (Appleyard et al., 2002; CCAMLR, 2004; Laptikhovsky et al., 2006; Ashford et al., 2012): a South American stock; a South Georgia Islands stock, a Macquarie Islands stock, and a Southern Indian Ocean Islands stock.

In the South American stock, each country manages their fisheries independently.

There are two Patagonian toothfish management units in Chile: i) North 47°S, including Chilean Regions XV to northern XI, ii) South 47ºS, southern Region XI to Region XII, both areas from the coastline to the EZZ.