Southern Ocean Southern Hemisphere, with the greatest concentration located on and around Antarctica. Four of the 18 penguin species live and breed on the mainland and its close offshore islands. Another four species live on the subantarctic islands. Emperor penguins have four overlapping layers of feathers, keeping them warm. They are the only Antarctic animal to breed during the winter. There are relatively few fish species in few families in the Southern Ocean. The most species-rich family are the snailfish (Liparidae), followed by the cod icefish (Nototheniidae) and eelpout (Zoarcidae). Together the snailfish, eelpouts and notothenioids (which includes cod icefish and several
Flightless cormorant the 1983 an El Niño-Southern Oscillation (ENSO) event resulted in a 50% reduction of the population to just 400 individuals. The population recovered quickly, however, and was estimated to number 900 individuals by 1999. This species inhabits the rocky shores of the volcanic islands on which it occurs. It forages in shallow coastal waters, including bays and straits. Flightless cormorants are extremely sedentary, remaining most or all of their lives, and breeding, on local stretches of coast-line several hundred metres long. Their sedentary nature is reflected in a genetic differentiation between the main colonies, and particularly between Fernandina and Isabela