Fisheries for fin fish and krill began to increase in Antarctica in the late 1960s and 1970s and by 1982 the krill catch rose to a peak of over 520,000 tons removed. This increased harvest caused concern among scientists in Antarctic Treaty nations that fish and krill stocks would be depleted beyond recovery unless steps were taken to manage these fisheries. Here I discuss measures taken to avoid the loss of critical and keystone marine species in Antarctica with the addition of the Convention for the Conservation of Antarctic Living Marine Resources, or CCAMLR, to the Antarctic Treaty in 1980. This agreement caused treaty nations to conserve an entire marine ecosystem and monitor indicator species that represent the health of that ecosystem.  Today, CCAMLR sets quotas for fishery species including krill that help sustain their populations, though many obstacles remain.