Researchers say what was once the world’s second-largest colony of emperor penguins has “now all but disappeared” after changes in sea-ice conditions made their typical breeding grounds highly unstable.

A group of researchers from the British Antarctic Survey (BAS) published their findings in the Antarctic Science journal on Thursday. The team said in a statement that they studied “very high resolution satellite imagery to reveal the unusual findings.”

According to their research, satellite imagery showed that the emperor penguin colony at Halley Bay in Antarctica had drastically decreased over the past three years on account of breeding failures caused by severe changes in local environmental conditions.

“For the last 60 years the sea-ice conditions in the Halley Bay site have been stable and reliable,” the team said. “But in 2016, after a period of abnormally stormy weather, the sea-ice broke up…