08 July 2016

Penguin colonies at risk from erupting volcano

Chinstrap penguins.
Image © Harriet Clewlow
SOUTH SANDWICH ISLANDS – A volcano erupting on a small island in the subantarctic is depositing ash over one of the world’s largest penguin colonies.

Zavodovski Island is a small uninhabited island in the South Sandwich archipelago, part of the British Overseas Territory of South Georgia & the South Sandwich Islands. Its volcano Mt Curry has been erupting since March 2016. The island is home to around 1.2 million chinstrap penguins – the largest colony for this species in the world.

British Antarctic Survey (BAS) recently remapped this chain of volcanic islands and was alerted to a 7.2 magnitude earthquake last month in the vicinity. Researchers confirmed from satellite imagery that not one but two volcanoes are erupting in the South Sandwich Islands – Mt Curry on Zavodovski Island to the north of the archipelago and Mt Sourabaya on Bristol Island to the south.

Following the earthquake, fishing vessels in the area captured photos of the Zavodovski Island eruption. They show the main volcanic vent is on the western side of the island, but the prevailing wind is blowing the smoke and ash to the east, and depositing much of it on the lower slopes of the volcano. These are home to the chinstrap penguins, closely packed in great numbers, as well as around 180,000 macaroni penguins.

Satellite images have confirmed that between one third and one half of the island has so far been covered in ash. At the time photos were taken, the adult chinstraps were moulting and therefore unable to leave the island.

“As the images were captured during the moult period for the chinstraps, the consequences could be very significant. When the penguins return to breed later in the year, it will be interesting to see what impact this event has on their numbers,” said BAS penguin ecologist Mike Dunn.

BAS geographer Dr Peter Fretwell, who was involved in the remapping of the archipelago, said, “We don’t know what impact the ash will have on the penguins. If it has been heavy and widespread it may have a serious effect on the population.

"It’s impossible to say but two scientific expeditions are scheduled to visit the region from later this year and will try to assess the impact of the eruption.”

Penguin colonies at risk from erupting volcano [media release], 6 July 2016, British Antarctic Survey

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