Remote subantarctic island experiences population boom

28 March 2001

Dramatic changes in the population and distribution of plants and wildlife on Australia's subantarctic outpost of Heard Island are among the many exciting research findings, as a result of an extensive research program on the remote volcanic island. The derelict station at Atlas Cove was also successfully cleaned up. The researchers and clean-up team return to Hobart tomorrow aboard the Antarctic resupply vessel Polar Bird.

An international team of plant scientists have carried out comprehensive studies of tundra plants on the Island. Initial findings from the studies indicate that global climate warming has resulted in large new expanses of endemic plant species. One such species, the Aceana magellancia (a species related to roses), has spread dramatically in the warmer conditions, overtaking other native plant species in the area. Plant study leader on the Island, Dr Dana Bergstrom last visited the Island with the Australian Antarctic Program 14 years ago.

"Heard Island is still recovering from the last ice age. Combined with the effects of the current increase in global climate warming, many previously poorly vegetated areas are now lush with plants and the receding glaciers are now revealing new land for colonisation", Dr Bergstrom said.

Dr Bergstorm said that the data collected from the plant studies is a major contribution to a new international Antarctic climate change program RiSCC (Regional Sensitivity to Climate Change in Antarctic Terrestrial Ecosystems). "We are working very closely with other nations, with parallel studies occurring on the subantarctic Iles Kerguelen. Other studies in Antarctica, under this collaborative program, will follow". Dr Bergstrom said.

Bird and seal population numbers on the Island have also dramatically increased since previous studies. Dr Eric Woehler of the Australian Antarctic Division said that among the findings on seabird population recovery rates, there was a staggering increase in the King penguin population on the Island. "The records we have, photographic and data, reveal that the population totalled only three breeding pairs in 1947 - during our stint on the Island we have observed in excess of 25,000 pairs of King penguins. We have also found that the endemic Heard Island Cormorant, listed as vulnerable under national and international agreements, now has an estimated breeding population of 1200 pairs. On a less positive note we have also found our first evidence of the ingestion of plastic particles by seabirds breeding at Heard Island", Dr Woehler said.

Other studies undertaken during the extensive summer program on the Island have focussed on volcanic xenoliths - indicators of activity within the earth's molten core; archaeological work looking at mid 19th Century sealing activities; counts of Antarctic fur seals - finding a current estimated population of 28,000 adults and 1000 newborn pups - a dramatic increase from near extinction through sealing in the early 1800s; and insect studies revealing beetles living much of the year at high altitudes beneath the snow.