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 to Fernandina is a huge potential threat to the species. Fishing with nets poses a current threat to the species; this not only reduces the availability of the cormorant's food, but also often results in birds becoming caught in the nets and killed. Seasonal cold water has shaped the breeding strategy of flightless cormorants. A rise of several degrees of sea surface temperature during the breeding season or persisting throughout the breeding season (i.e. during ENSO events) results in low breeding success. ENSO events appears to have increased in frequency and severity in recent decades, possibly associated with climate change.