Four out of five emperor penguin colonies in the Bellingshausen Sea region of Antarctica likely lost chicks late last year due to the loss of sea ice beneath their breeding grounds, according to a new study.
Some parts of this coastal region lost all their sea ice in November, which is probably before the penguin chicks have outgrown their waterproof adult feathers and learned to swim. This is the first time scientists have seen the widespread failure of multiple penguin colonies in one region, the researchers said.
“Right now, we’re not sure if it’s just a blip,” said Norman Ratcliffe, a seabird ecologist at the British Antarctic Survey and one of the authors of the new study. “But if this becomes a consistent phenomena over a longer period of time, it will obviously have ramifications for the species..”
Sea ice levels around Antarctica by 2023 are likely to reach record lows by a wide margin. This sudden decline has scientists alarmed and there is some speculation that Antarctic sea ice is entering a new, unstable state.
“Events like this may become more common in the future,” said Dr. Ratcliffe, referring to early sea ice loss and subsequent penguin breeding failures. “So we may be looking at a harbinger of future Antarctica.”
Antarctica’s Bellingshausen Sea region is so remote, that researchers have observed penguin colonies using satellite images to track their droppings, called guano, which leave a distinctive reddish-brown trail. on snow and ice.
Emperor penguins rely on the sea ice attached to the edge of the Antarctic continent as habitat to lay their eggs and raise their young until they can swim and fend for themselves.
After remaining steady and even increasing for years despite climate change, Antarctic sea ice began to decline in 2016. Sea ice extent around the continent hit a record low in 2022. Bellingshausen Sea , the area along the western side of the Antarctic Peninsula where five penguin colonies are located, was the worst affected region last year.
Emperor penguins sometimes choose new breeding sites when old sites fail, and some join other colonies. But scientists have only seen them move short distances, and as more and more sea ice melts, the entire coastal region could become inhospitable.
Scientists estimate that there are currently around 600,000 emperor penguins in the wild, in 61 known colonies. In 2022, the United States listed the species as threatened under the Endangered Species Act. Although these penguins do not live in the United States, the list encourages international cooperation to protect the animals and requires the government to consider them when evaluating federal greenhouse emission projects. gas.
Aside from human-induced climate change, the past three-year natural La Niña climate phenomenon in the Pacific Ocean likely contributed to the Bellingshausen Sea having less sea ice. Flipping through El Niño conditions this year could help that particular region.
The continent is just beginning to emerge from its long polar night, when emperor penguin colonies are invisible in the darkness of satellites. As they are seen again, the British Antarctic Survey and researchers from other countries continue to monitor each colony. They expect newer satellites — which are starting to track penguins instead of just their guano — to help improve estimates of populations.
While the most recent study, published on Thursday in the journal Communications Earth & Environment, which focuses on the Bellingshausen Sea, said Dr. Ratcliffe that breeding failure rates last year were higher than expected across Antarctica.
Annie Schmidt, an ecologist and director of the Antarctica program at the consultancy Point Blue Conservation Science, said that this study yielded an important observation of breeding failure across the region. Dr. Schmidt was not involved in this research, but studied emperor penguin colonies.
“This is an early warning that this is starting to happen,” he said.
Previous research has suggested that if human-caused climate change continues at its current projected rate and the planet warms by 2.6 degrees Celsius by 2100 compared to preindustrial levels, the emperor penguin could disappear. almost 90 percent of their population and on the brink of extinction. But if countries meet the goals of the international Paris Agreement to limit global warming to below 2 degrees Celsius, emperor penguins will be better off. They may still lose 30 to 40 percent of their numbers, but scientists believe that the population can be stable and survive.