- guardian.co.uk, Sunday December 17 2000 00.26 GMT
Andrew Brierley will spend a lonely Christmas this year - on a boat in the Antarctic with a robot submarine, several million tiny shrimps and little else for company.
His festive sacrifice should pay dividends, however, for the biologist has embarked on a mission aimed at determining the fate of sea life in the Southern hemisphere.
'What happens under the ice is of fantastic importance to the oceans' food chain - and as the world heats up, it is becoming clear there could be profound and damaging consequences,' Dr Brierley told The Observer before he left for the Falklands last week.
The purpose of Brierley's mission is simple: to use Britain's £5 million revolutionary robot submarine, Autosub - the most advanced underwater probe ever built - to study krill, the hub of the southern ocean's food chain.
Krill are small, shrimp-like creatures that graze the underside of sea ice. 'They are crucial to all wildlife in the southern oceans,' said Brierley, of the British Antarctic Survey. 'Krill eat a form of algae called phytoplankton, and in turn are eaten by everything else - fish, seals, polar bears. If krill die out, so would all these creatures.'
Researchers have recently discovered that krill thrive in climatic extremes. When winters are severe and sea ice is thickest, then the crustaceans do well. In warm, iceless periods, they decline.
'We are not sure why this happens,' Brierley said. 'Either the sea ice provides a good surface for phytoplankton to grow on, and so provides krill with lots of food, or it stops predators like penguins and seals from getting at them.
'It is crucial that we find out exactly what is going on, however - for if global warming continues, and sea-ice shrinks as we expect, then the world's krill could die out, taking out all creatures that feed on them.'
Unfortunately the everyday life of the krill has been a closed book for scientists. The vibrations of their icebreakers and their stomping on ice floes tend to drive off shoals long before they can get near them. However, such ignorance should disappear with the use of Autosub, the world's first 'intelligent' submarine.
Autosub is a torpedo with a brain that can dive to depths of four miles and stay underwater for days while moving at a stately 2mph. Instruments are stored in its nose, while 5,000 alkaline-manganese batteries, enough to provide a kilowatt of power for 100 hours, are kept in its carbon-fibre central hull.
Fins automatically direct the craft downwards, counteracting its built-in buoyancy. 'That means that, if the sub stops for any reason, it automatically rises to the surface,' said Glyn Griffiths, head of the ocean technology division at Southampton Oceanography Centre.
'Another crucial point is that Autosub runs extremely quietly. We used it to study herring earlier this year and found it could pass right beside shoals without disturbing them. That is helpful when you are investigating marine life.'
Thus Autosub - on its first mission to the polar regions - will be able to investigate krill from close quarters. Brierley, on his surface craft, will be able to monitor how they feed, and how they are eaten by predators - including himself.
'I'll probably have a couple of them as a starter for my Christmas lunch. They're quite tasty. You just put a couple on a plate and microwave them for 20 seconds. It would be a shame to waste them, after all.'
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