Emperor penguins at risk in sea ice loss Emperor penguins. Credit: Glen Grant, U.S. Antarctic Program, National Science Foundation. WOODS HOLE, Mass., June 20 (UPI) -- The population of emperor penguins appears likely to decline this century as climate change reduces the extent of Antarctic sea ice, U.S. researchers say. A study led by the Woods Hole Oceanographic Institution with the National Center for Atmospheric Research and other organizations at a much-observed colony of emperor penguins in Terre Adelie, Antarctica, suggests the number of breeding pairs may fall by about 80 percent by 2100. "The projected decreases in sea ice may fundamentally alter the Antarctic environment in ways that threaten this population of penguins," study co-author Marika Holland said in a release issued by the center Wednesday. The study used computer simulations of climate to examine how the sea ice may vary at key times during the year, such as during egg laying, incubation, rearing chicks and non-breeding season. The simulations pointed to a significant decline in the colony at Terre Adelie, a coastal region of Antarctica where French scientists have conducted penguin observations for more than 50 years. "Our best projections show roughly 500 to 600 breeding pairs remaining by the year 2100," lead author Stephanie Jenouvrier, a Woods Hole biologist, said. Today, the population size is around 3,000 breeding pairs. Another penguin population, the Dion Islets colony close to the West Antarctic Peninsula, has already disappeared, possibly because of a decline in Antarctic sea ice, she said.