April 11 (UPI) -- According to new research, one of Antartica's largest gentoo penguin colonies has been nearly wiped out by volcanic ash several times over the last 7,000 years.
Researchers analyzed layers of volcanic ash and penguin guano among sediment cores sampled from Ardley Island in Antarctica's South Shetland Islands.
The island currently hosts 5,000 pairs of gentoo penguins, and has generally featured favorable climatic conditions. But as the research showed, the island's proximity to Deception Island and its active volcano has proved perilous to resident penguins.
"On at least three occasions during the past 7,000 years, the penguin population was similar in magnitude to today, but was almost completely wiped out locally after each of three large volcanic eruptions," Steve Roberts, researcher with the British Antarctic Survey, said in a news release. "It took, on average, between 400 and 800 years for it to re-establish itself sustainably."
As the findings showed, volcanic ash can have devastating affects on even large, healthy penguin populations. The toxic ash can burry penguin chicks unable to escape to the safety of the ocean with their parents. Nesting sites buried in ash can remain unusable for several years.
Researchers hope their findings -- detailed in the journal Nature Communications -- will improve the ability of scientists to predict the impacts of climate change on penguin colonies.
"Changes in penguin populations on the Antarctic Peninsula have been linked to climate variability and sea-ice changes, but the potentially devastating long-term impact of volcanic activity has not previously been considered," concluded Claire Waluda, penguin ecologist from BAS.