Sydney

Getting warmer: botanists hunt for clues on Heard Island. Credit: DOUG THOST

The first survey for a decade of animals and plants on Australia's Heard Island, 4,000 kilometres southwest of Perth, has unearthed dramatic evidence of global warming's ecological impact.

The survey found that glaciers on the sub-Antarctic island have retreated by 12% since the first measurements were taken in 1947. This has been accompanied by a rise in sea surface temperature of up to 1 °C and rapid increases in flora and fauna.

Dana Bergstrom, an ecologist at the University of Queensland in Brisbane, who led the survey's study of plant life, says areas that were previously poorly vegetated are now “lush with large expanses of plants”.

Populations of birds, fur seals and insects have also expanded rapidly since earlier studies, says Eric Woehler of the Australian Antarctic Division at Kingston, Tasmania, part of Australia's environment department. According to Woehler, the number of king penguins has exploded from only three breeding pairs in 1947 to 25,000, while the Heard Island cormorant, listed previously as “vulnerable”, has increased to 1,200 pairs. From near extinction, fur seals now number 28,000 adults and 1,000 pups.

Australia has now committed to surveying Heard Island every two years for the next decade as part of an international programme to measure the response of ecosystems to climate change in the Antarctic.