Environmentally driven variability in abundance has caused large shifts in effort between the major ommastrephid stocks which do not seem to cycle synchronously. When catches have been generally low worldwide this has led to attempts to locate new fisheries such as in the mid 1990s when Illex argentinus abundance was particularly low on the Patagonian Shelf and exploratory fishing for Martialia hyadesi took place in CCAMLR waters south of the Antarctic Polar Front. This led to recommendations for precautionary measures to protect dependent species of higher predators (Rodhouse, 1997). Future changes in abundance of the currently exploited species are likely to increase the likelihood of development of new fisheries and extend exploitation offshore of the shelf regions. This will create several new challenges for management, both for ecological and socioeconomic reasons. The dynamics of mesopelagic systems are poorly understood and squid may be keystone species in some areas such as the Antarctic Polar Frontal Zone (Rodhouse and White, 1995) and possibly elsewhere such as the Indian Ocean. Some populations may lie entirely outside EEZs of nation states.