Erik van Sebille is looking for something very much out of the ordinary in the Southern Ocean: plastic. He has come to one of the most remote parts of the world – as far as it is possible to go from major concentrations of people – to look for the stuff humans throw away.  Van Sebille, an oceanographer at the University of New South Wales and one of the research leaders on the Australasian Antarctic Expedition, was one of the first to start his scientific work aboard the Shokalskiy. In the morning on our first full day at sea, he threw a two-metre-long plankton net, with a pint-sized jar attached to one end, overboard. After five minutes dragging the assembly behind the ship, he fished out the jar and held in his hands something that looked a bit like pea soup – seawater filled with plankton, krill and, perhaps, bits of plastic. For his research, he will take many more seawater samples at different latitudes, sieving each one to identify the constituent parts.  The plastic he is looking for is the stuff that starts off as consumer goods and ends up in the sea as waste. The plastic is broken down over time, by sunlight, into fragments no more than a millimetre across. These particles can float for hundreds to thousands of years on the surface of the sea. Scientists have identified huge areas of the North Atlantic and Pacific oceans, for example, where the water currents force the plastic particles to accumulate. In some of these places, there seems to be more plastic than plankton on the surface. The particles can attract algae, absorb toxic chemicals and have major impacts on the entire marine food chain.  So far no one has carried out measurements of plastic in the Southern Ocean, partly because it is so remote but also because oceanographers have assumed that the prevailing surface currents would limit any plastic build-up there. Van Sebille is aiming to fill that knowledge gap.  “We want to find out, in a systematic way, how much plastic there is,” he tells me. “Especially if, as we go from relatively close to New Zealand and further south, how quickly the amount of plastic actually decreases.”  General measurements of the sea also began last night: one of the science teams attached a half-metre-long metal tube, bristling with electronic sensors, to a long rope and plunged it into the sea. Dragged along behind the boat for the duration of the trip to Antarctica, the $25,000 “Exoprobe” will record a range of variables – sea temperature, salinity, pH – every few seconds to build a detailed picture of the Southern Ocean along our route.  On the 1911-14 expedition that Douglas Mawson led, his team pulled up buckets of sea water a few times and used a thermometer to measure its temperature. The 2013 version can measure the sea's features almost continuously day and night, providing thousands of data points every day. In recent decades, Earth-observation satellites have measured the surface temperature of the ocean from space, but no one has directly probed it in this way for more than a century.  By lunchtime, the researchers had reeled in the Exoprobe to download its first 12 hours of measurements and, more importantly, to ensure that it was still in one piece and hadn't been bitten by any inquisitive sharks.  On board, the mood was bright. The sun unexpectedly warmed the decks and the wind was light. On the observation deck above the bridge, it was so peaceful that, at times, it would have been possible to believe we were on a tropical cruise rather than aboard a working scientific research vessel. The wave of sea sickness had, thankfully, calmed and many of my fellow passengers had recovered enough to start getting involved with the research projects.  Some identified and counted birds from vantage points at the bridge of the ship. Others looked on at the stern deck as expedition leader Chris Fogwill, a glaciologist at the University of New South Wales, began his collection of plankton from the sea surface, using the same set-up of jars and nets that van Sebille was using to find plastic.  “The Southern Ocean, at this time of year, really starts to bloom with huge amounts of biological productivity going on,” says Fogwill. “What we're going to do is sieve it and then we'll see what forms of plankton we have in there once we have it all cleaned up and ready to go. We'll do this every day to get the latitudinal variability as we go down.”  The data Fogwill collects will provide a baseline of information for scientists who want to study the variability of the Earth's climate over millions of years.  “The plankton on the floor of the ocean, you can compare it with tree rings,” says van Sebille. “There's layers being formed over millions of years.”  As the plankton that lives at the surface of the sea dies, it sinks down to the bottom - what oceanographers call “marine snow”. In some places, this can be hundreds of metres deep on the sea bed. Studying what species are present in the different layers can provide insights into past climate. “Sometimes you have tropical species, sometimes sub-tropical,” van Sebille. “To interpret that data you need to have a baseline, you need to know what's at the surface of the ocean right now.”  Other scientific research projects – including surveying sea mammals and taking cores of mud and ice – will begin in the coming days. And, very soon, we'll see our first penguins. Meanwhile, as the sun went down (though it never went dark) on the second day, a few passengers reported seeing something equally beguiling: a pod of dolphins at the bow of the Shokalskiy, leaping and racing our lumbering ship.  Highlights of the day: Not feeling seasick as soon as I woke up. Seeing dolphins racing ahead of the ship.  Lowlight of the day: My jetlag still hasn't passed. Endless sunlight isn't helping with the necessary adjustments.
Alok Jha: In one of the remotest places on Earth, a scientist is measuring for the first time the concentration of plastic particles that can float on the sea surface for hundreds or even thousands of years