Rapidly shrinking sea ice in the northern and southern hemispheres due to global warming has dire implications for a multitude of animals, including the Emperor penguins in East Antarctica.

Emperor penguin. (Photo: Stephanie Jenouvrier, Woods Hole Oceanographic Institution)

Environmental changes have been wreaking havoc on penguin populations across the ice-sheathed continent in recent years. According to a report from the Woods Hole Oceanographic Institution (WHO), in 1948 and the 1970s, scientists studying the Dion Islets penguin colony, close to the West Antarctic Peninsula, recorded more than 150 breeding pairs. By 1999, the population was down to just 20 pairs. By 2009, it had vanished entirely. They believe the changes that killed the Dion Islets colony may be doing the same to the Emperors.

Unlike other sea birds, Emperor penguins breed and raise their young almost exclusively on sea ice (frozen seawater floating on the surface of the ocean). In normal circumstances, only 50 percent of Emperor chicks survive to the end of the breeding season, and only half of those fledglings survive until the next year. If the sea ice breaks up and disappears early in the breeding season, as has been happening the last several years, massive breeding failure may occur.

Biologist Stephanie Jenouvrier with an Emperor penguin chick/Antarctica (Photo: Stephanie Jenouvrier, Woods Hole Oceanographic Institution)

Emperor penguins/Terre Adelie, East Antarctica. (Photo: Stephanie Jenouvrier, Woods Hole Oceanographic Institution)

The disappearing ice may also affect the penguins’ food source; primarily fish, squid, and krill, a shrimplike animal, which in turn feeds on zooplankton and phytoplankton, tiny organisms that grow on the underside of the ice. If the ice goes, so too will the plankton.

Researchers have calculated that if greenhouse gas emissions continue to rise at projected levels, the loss of Antarctic sea ice will shrink penguin population numbers slowly until about 2040, after which they will decline at a much steeper rate with catastrophic consequences.

Meanwhile, the human world sits on its hands.

Source: Woods Hole Oceanographic Institute.