Hardiness Of Plankton

Press, Volume CI, Issue 29716, 9 January 1962, Page 10

Hardiness Of Plankton

An Australian has established that phytoplankton—the plant component of plankton—can live and grow under Bft of sea ice in Antarctic waters at a temperature of -2d eg. centigrade The scientist, Dr. John Bunt, said that all life in the sea depended on the activity of these micro-organisms, and he had shown them to be tremendously productive in these conditions for a few weeks of the Antarctic summer. “This must be of considerable importance to marine biology,” he said, “and all life in the region, even the number of penguins and seals, depends on it.” Dr. Bunt, a lecturer in microbiology at Sydney University. spent the last two months at McMurdo Sound working on this project with the United States Antarctic Research Programme. He worked at Mawson. the Australian base, on a similar project In 1956. Before he began his research it was not known whether phytoplankton could grow under the sea ice,

where there is very little light and temperatures are low.

He said he determined whether the plankton was growing or not by introducing radioactive carbon dioxide to a sample, incubating it. filtering off the water, then measuring the intensity of radiation. He also counted the number of organisms and measured the chlorophyll content.

He discovered that the organisms are able to carry out their normal plant activities under the sea ice, but only at the height of summer for a few weeks. “I was there only two months and the work has only started.” he said. “We still don’t know the major factors that control the growth of these organisms.” Dr Bunt hopes to get an opportunity to continue his studies m the Antarctic, but he is now on his way back to Australia.