At two of the most remote locations on Earth — Zavodoski Island and Bristol Island in the far south Atlantic Ocean, a recent 7.2 magnitude earthquake and volcanic eruptions are potentially affecting one-half of the world’s entire population of chinstrap penguins (Pygoscelis Antarctica). Zavodoski and Bristol islands are part of the South Sandwich Island chain, in the South Atlantic Ocean, at the far eastern end of the Scotia Arc, approximately 1,150 mi (1,850 km) east of the Antarctic Peninsula and South Shetland Islands, and represent a major biological hot spot for penguins and other seabirds.
The islands’ remoteness and challenging coastlines preclude regular biological censuses, but, in 2011, Oceanites assisted in sponsoring an extensive survey of the South Sandwich Islands onboard the yacht Golden Fleece, captained by Jérôme Poncet. This was the first survey since the late 1990s and the most comprehensive ever accomplished, completed through a combination of direct counting, global positioning system (GPS) mapping, and interpretation of high-resolution commercial satellite imagery. Results have just been published (Lynch, et al. Polar Biology, DOI 10.1007/s00300-015-1886-6, 2016).
The South Sandwich Islands host a minimum of 1.3 million breeding pairs of chinstrap penguins (Pygoscelis antarctica), the largest chinstrap colony in the world; as well as 95,000 breeding pairs of macaroni penguins (Eudyptes chrysolophus), several thousand breeding pairs of gentoo penguins (Pygoscelis papua), 125,000 breeding pairs of Adelie Penguins (Pygoscelis adeliae), and 1,900 pairs of southern giant petrels (Macronectes giganteus).
In context, 1.3 million breeding pairs of chinstrap penguins represent nearly half of the world’s chinstrap penguin population, which is estimated to comprise 2.67 million breeding pairs. Also critical is that the chinstrap penguin colonies across the Scotia Arc, from the Antarctic Peninsula in the west to the South Sandwich Islands in the east, represent one genetically interconnected breeding population (Freer, et al., 2016).
Via fisheries observer reports last month, the British Antarctic Survey has now reported that Mt. Curry on Zavodovski Island at the northern end of the chain and Mt. Sourabaya on Bristol Island to the south are erupting. The recent survey noted 600,000 pairs of chinstraps breeding at Zavodoski Island and >960 pairs of chinstraps breeding at Bristol Island. Ash cover appears to be extensive on both Zavodoski and Bristol.
Ron Naveen, president/founder of Oceanites and co-principal investigator of the Antarctic Site Inventory, noted:
“While the earthquake and eruptions seem to have occurred late in the penguins’ breeding season, we won’t be able to fully assess impacts until the start of the next breeding season. The great concern, however, is that the South Sandwich chinstraps represent a relatively stable population of this species, compared to the dramatic decline of chinstraps in the vastly warming western Antarctic Peninsula. This clearly has enormous implications for the careful management of fishing activities in this sector of the south Atlantic Ocean.
“As noted in our census paper, the South Sandwich Islands have received considerably less attention than either South Georgia or the western Antarctic Peninsula, and little is known about changes in prey availability, foraging effort, diet, phenology, or demography. Casual examination of the guano suggests that penguins are eating both krill and fish in the South Sandwich Islands, though more careful analysis is clearly required to compare penguin diet in this region to Antarctic Peninsula populations, for example, where the chinstraps’ diet is more krill-focused.”
Heather Lynch, assistant professor of Ecology & Evolution at Stony Brook University and co-principal investigator of the Antarctic Site Inventory, is expert in surveying penguin colonies from satellite imagery and will be remotely tracking these changes. She commented:
“This represents a once-in-a-century opportunity to study how penguins respond to and recover from massive ecological disturbance. Clearly, this is not the first, nor will it be the last, time that chinstrap penguins have had to deal with major volcanic eruptions, but it’s perhaps the first time we have the tools to study it in detail. The interactions between biology and geology are complex and hard to study, but over long periods of time these kinds of disturbances shape the biogeographic patterns we see every day.”
Tom Hart, University of Oxford Department of Zoology, who participated in the 2011 expedition to the South Sandwich Islands, commented:
“The South Sandwich Islands are a place like no other; hundreds of thousands of penguins nest in supercolonies on the slopes of glacier covered, smoking volcanoes. So, it’s entirely natural that occasionally one of these volcanoes erupts and in the long term it’s likely to be natural that a population crashes as a result. That said, we’ve never witnessed one of these events and we need to incorporate it into our conservation plan for chinstrap penguins in particular.
Depending on exactly when this eruption started, the colony could be severely impacted, but equally if this happened before moult, the population could largely have gone to sea or nearby islands. We know from time-lapse cameras on Saunders Island that the South Sandwich colonies are likely to have been moulting when the eruption started.
Either way, we won’t know the extent of the problem until we get back to the islands. One upside is that the South Sandwich Islands have been doing well and they are likely to recover. Studying the recovery of Zavodovski will give us a comparison and insight into chinstraps elsewhere.”
For further information, please contact:
Ron Naveen, Oceanites
+1 202 237 6262
Dr. Tom Hart
+44 1865 600 170
- Lynch, et al., In stark contrast to widespread declines along the Scotia Arc, a survey of the South Sandwich Islands finds a robust seabird community, Polar Biology, 2016
- Freer, et al., Limited genetic differentiation among chinstrap penguin (Pygoscelis antarctica) colonies in the Scotia Arc and Western Antarctic Peninsula, Polar Biology, 2015)
- Video of Tom Hart, surveying/censusing chinstrap penguins at Zavodoski Island, January 2011
- Folder of photographs by Tom Hart from the Oceanites co-sponsored research expedition to the South Sandwich Islands, January 2011