Antarctic scientists are warning growing tourism numbers could threaten the frozen continent's fragile environment.
About 40,000 researchers and tourists visit Antarctica each year, most to ice-free areas that make up less than one per cent of the continent.
Those areas also contain most of its wildlife and plants but only 1.5 per cent of them are protected, Australian scientist Dr Justine Shaw said.
"Many people think that Antarctica is well protected from threats to its biodiversity because it's isolated and no one lives there," Shaw said.
"We show that's not true."
Shaw said more protected areas were needed to better guard against the threat posed by a booming Antarctic tourism industry.
"(We need) to protect a diverse suite of native insects, plants and seabirds, many of which occur nowhere else in the world," she said.
"We also need to ensure that Antarctic protected areas are not going to be impacted by human activities, such as pollution, trampling or invasive species."
The study, published in the journal PLOS Biology, found all 55 protected areas lie close to sites visited by people and seven of those are at high risk of biological invasion.
Five important ice-free areas are completely unprotected.
The simplicity of the ecosystems makes them more vulnerable to invading grasses and insects, Monash University's Professor Steven Chown said.
"The very real current and future threats from invasions are typically located close to protected areas," he said.
"Such threats to protected areas from invasive species have been demonstrated elsewhere in the world, and we find that Antarctica is, unfortunately, no exception."
The continent also falls well short of international biodiversity protection targets, the study found.
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