At the bottom of the world lies a cluster of blue stations, pinpricks among the vast glaciers and frigid waters. This snowy desert is where 20 people will live and work for the next six months in winter. Kim Bernard is among them.
“I was once told by former astronaut Dr Scott Parazynski that it was quicker to get someone in need of medical care down from the International Space Station than from Palmer Station,” said Bernard, an oceanographer at Oregon State University (OSU), who is leading the only science expedition to spend all winter there this year.
Her team is enduring darkness and frigid temperatures to collect a rather tiny, translucent-pink species found in all Earth's oceans. The ones in Antarctica, however, are not quite like the rest.
Krill are shrimp-like crustaceans with beady black eyes that live for up to 7 years. They may be small but they are powerhouses of the ocean, a keystone species upon which most marine creatures rely. This includes the largest animal in the world – the blue whale – to spotted seals, Adélie penguins, and tentacled squid. Antarctic krill are the largest of all Earth’s krill species, growing to up to 6.3 centimeters (2.5 inches) in size.
It is not an expedition for the faint of heart. Palmer Station is located outside the Antarctic Circle where temperatures drop to -10°C (14°F) and winds crank up to 70 knots or more in austral winter. If that made boating for krill difficult, add just five hours of light each day.
To prepare, Bernard and her team spent a year getting ready for their mission. By her side are Kirsten Steinke, a PhD candidate, and Julia Fontana, a senior undergraduate student. The remaining crew are contracted support staff.
“Palmer Station is very isolated during the winter,” said Bernard. “It's part of the reason why we will be there for so long, in fact. Once the sea ice comes in, it can be impossible for the R/V Laurence M. Gould to reach the station.”
The isolation and inky darkness are worth it for the researchers. Krill may be small but their plight reveals something much bigger about our world and changing times. Warming temperatures are causing sea ice to form later in the season, providing less habitat for the algae to grow on and, in turn, less food for juvenile krill to feed on.
“Winter is a critical time of year for Antarctic krill, particularly the early life-stages. It's a time of year when there is little food available for the young krill to feed on, yet they must somehow find food to survive,” said Bernard.
“Winter is also a really challenging time for scientists to conduct research in Antarctica. It's dark most of the time, sea ice restricts where a research vessel could go, etc. So, although we know that winter is an important time of the year for Antarctic krill, we actually know very little about how they cope with the harsh, food-limited conditions.”
So far, the team have collected live krill on their voyage south to Palmer Station, spending two nights scooping up the critters. The tools are fairly basic: an echosounder (essentially a fish finder) and a large net called an Isaacs-Kidd Midwater Trawl.
Bernard has made previous trips to Antarctica, all during the summer season. During her first year of study, the sea ice formed early and juvenile krill were able to meet their winter energy needs. The year after was a different story. The sea ice formed late, meaning ice algae made up only 16 percent of their energy needs – a significant loss.
But how exactly this loss affects the krill needs to be investigated further. There are somewhere in the realm of 500 million tonnes of Antarctic krill in the Southern Ocean – more than the weight of our planet's 7.5 billion people. However, climate change and human harvesting may change these odds.
"When sea animals eat, respire, and defecate, it moves carbon around the ocean. Krill are super abundant and so, collectively, they move a lot of carbon," said Dr Simeon Hill, an ecologist with the British Antarctic Survey who was not involved in the research but has co-led a recent study on Antarctic krill. "All of this carbon reaches krill via phytoplankton, which are their main food source and a good proportion of this carbon will have come from the atmosphere.
"Krill also form very dense swarms and, when a whole swarm is feeding and defecating, a lot of the fecal carbon will reach the seabed because there is too much of it for the bacteria in the water column to recycle. So, because they are enormously abundant and feed in dense swarms, krill play a valuable role in delivering atmospheric carbon to the seabed."
Onboard the research vessel, Bernard and her team caught nets of krill, quickly sorted through the assemblage in large tubs of seawater on the back deck of the ship, and picked out as many healthy, live specimens as possible. They transfered them to two large holding tanks, where they will remain until they arrive at Palmer Station a day or two later.
Palmer Station is located in a region that is among the fastest warming on the planet. There has been an increase in winter surface air temperature of ~1?C per decade in the last 60 or so years. The remote station operates year round, so it is an ideal, albeit difficult, spot to conduct winter research.
“It takes a huge amount of preparation for an expedition like this,” said Bernard. “Part of the planning involves the Principal Investigator (in this case, me) providing a full list of what they will need while on station."
The team also had to pass “PQ exams” – essentially a series of rigorous medical and dental tests to ensure they are healthy and fit in a region with limited medical facilities and in a harsh, often unforgiving environment. If they pass, they are deemed PQ, or Physically Qualified.
They set off in early April for the bottom of the world and will not emerge from its depths until mid-October. Their expedition is funded by the National Science Foundation.
The research vessel Laurence M. Gould is an icebreaker, named after polar explorer and geologist Laurence McKinley Gould. The R/V – which has an onboard hot tub, mind you – is capable of breaking through a foot of ice with continuous forward motion.
Once the team reach Palmer Station, they will offload their krill catch in the holding tanks and begin their experiments. They will select the best-looking juvenile krill and place them into 200-liter (50-gallon) tanks filled with different types of food and seawater from their surroundings. Over the following months, they will conduct various measurements of them to determine their growth, lipid content, respiratory physiology, and reproductive development.
“The reproductive development aspect is what I will be doing for my PhD and I plan on staging the krill both externally and internally via dissection techniques to examine how diet might be affecting the timing of their reproductive development,” added Steinke.
The team are not only concerned about the krill’s food source, but also their own for such a long expedition.
“Food is transported to Palmer Station onboard the R/V Laurence M. Gould,” said Bernard. “In winter, we will get all the food we need for six months delivered once. The fresh vegetables and fruit will probably only last two to three weeks. All waste is removed from Palmer Station. Waste that can be recycled is, but is still removed from Antarctica.
“I think this is going to be the closest I'll ever get to going into space."