Posts tagged phytoplankton

High Impact Science in Antarctica

The Mertz Glacier as seen in 2007, extending 75 km out into the Southern Ocean

Antarctica was in the news this weekend when a 97 kilometer long iceberg the size of Luxembourg collided with the floating Mertz Glacier, breaking the famous glacier off at the base and generating a 2500 sq. kilometer iceberg. Each of these behemoths weigh several hundred billion tons, so the impact must have been quite a crunch!

Iceberg B9B collides with Mertz Glacier Tongue

At right is an image taken February 20th, several days after the impact: the broken Mertz Glacier Tongue is on the left side of the photo, and the colliding B9B iceberg is near the center-right.   The Mertz Glacier, which was sheared off at the base, was a significant barrier to westward drifting sea ice.  The Mertz Glacier is on the George V coast of East Antarctica, a region is famous for its high-velocity katabatic winds: sustained wind velocities at nearby Dumont D’Urville have reached 199 m.p.h!  These winds blow the pack ice out to sea, and because of the blocking geometry of the Mertz Glacier, this area generally remains ice-free all winter.

Fluorescence map of the Mertz Polynya in December 2007 (mertz Glacier is in lower right). Surface blooms are in red, and marine metagenomic samples were taken in areas marked with a star.

In the Austral summer of 2007, scientists from the J. Craig Venter Institute visited this ice-free area, or polynya, as part of the International Polar Year’s Census of Antarctic Marine Life (CAML). Because sunlight can freely penetrate the water column, polynyas are areas of enhanced productivity. Diatoms and other phytoplankton form massive springtime blooms, supporting whales, penguins, and much of the Antarctic food chain.  Above is a fluorescence ‘bloom map’ of the Mertz Polynya, just west of the Mertz Glacier. Our expedition on board the Aurora Australis attempted to capture a biological snapshot of the entire region, and Jeff Hoffman and I were able to collect samples ranging from thick blooms of  Phaeocystis antarctica to oligotrophic cold-water upwellings at the base of the Mertz Glacier.

CTD Rosette being deployed at the base of the Mertz Glacier to collect a sample from 1320m deep

CTD Rosette being deployed at the base of the Mertz Glacier to collect a sample from 1320m in depth

The region around the Mertz Glacier is equally famous as one of three regions where Antarctic Bottom Water is formed (the other two are the Ross and Weddell Seas).  Bottom water is created where saline water is extruded from newly formed sea ice.  This cold dense water sinks from the surface and becomes distributed into all of the world’s major ocean basins. Because the sea-ice in a polynya is continuously formed and blown out to sea, there is near continual production of brine and bottom water.  While in the Mertz Ploynya, Jeff and I used the ships 24-bottle CTD rosette to sample some of this bottom water, and one of the samples came from Buchanan Bay, right next to the area where the glacier split.  This sample came from a depth of 1320m, and may yield insight into bacterial activities at the base of the water column.  Additional deep water samples were taken in the Adelie Depression , the Mertz Bank, and the Mertz Depression, and one sample came from a depth of 3,690 m in the Southern Ocean.

Almost half of the water samples we collected have been sequenced using 454 sequencing technology and are in the process of annotation.  This biological data will form an important baseline as this region undergoes rapid change: loss of the protective geometry of the Mertz Glacier will likely cause changes in the formation of the Mertz Polynya, influencing both the biology of the annual spring bloom and the dynamics of bottom water formation.  Stay tuned for more updates on this exciting event and on the microbiology of the region.

Tafelbergs floating in the morning light, Mertz Polynya, December 2007

Antarctic epiblog: leaving McMurdo

Ice formation outside McMurdo Station

Ice formation outside McMurdo Station

After we took our samples out at the ice edge, we returned to  McMurdo Station for several intense days of demobilization.   We had to return all of the large drills, power equipment and camping gear, and spent a considerable time preparing our own gear for shipment back to the United States.  Our samples and some of our critical gear will go by air transport to Port Huemene in California, and the rest will be shipped back to the US by icebreaker during the January sealift.  In order to preserve the DNA and RNA of our plankton samples, we froze them in the field in liquid nitrogen: these samples will be air-shipped on dry ice to the J. Craig Venter Institute, where both DNA genetic code and RNA messages will be sequenced and decoded.

Mak in the Crary lab looking at some of Dawn's psychrophilic bactera

Mak in the Crary lab looking at some of Dawn's psychrophilic bactera

Mak Saito and his group will similarly take the phytoplankton protein samples back to the Woods Hole Oceanographic Institution and use a mass spectrometer to identify the protein fragments. The protein fragments .  Mak’s group also had some success culturing psychrophilic bacteria: psychrophiles are organisms which live around the freezing point, though many of the mechanisms which allow them to survive are unknown.  By

close-up of the Petri dish

close-up of the Petri dish

bringing back some live bacterial cultures to the laboratory, we will be able to grow them and study how both bacteria and larger phytoplankton can tolerate cycles of freezing and thawing, and also how the various proteins and enzymes in them remain flexible enough to function.

One student wrote in and asked if plants only grew in the sea ice and not on land.  the best answer I can give is that the temperatures in the sea ice are relatively stable: at the ice-water interface, the temperature is a constant 28 degrees Fahrenheit (-1.8 Celsius). If organisms can adapt to

Antarctica and Mars have much in common

Antarctica and Mars have much in common

that environment, then conditions are relatively stable for life. In contrast, life on land is relatively harsh, and in one day the soil surface can go from warm and sunlit to being raked by freezing 50 mph winds. I understand that there is a type of moss which grows near the streams in the McMurdo Dry Valleys, and I understand that there are some lichens around Cape Royds, but other than that the conditions are too harsh for land plants: all of the plant activity is in the ocean, growing as phytoplankton!

Close-up of desert pavement in Antarctica: Winds are so strong that small grains are blown away, leaving only gravel to 'pave' the surface of the soil

Close-up of desert pavement in Antarctica: Winds are so strong that small grains are blown away, leaving only gravel to 'pave' the surface of the soil

This brings up a good point: we love to hear your questions and comments, particularly from students and the public.  if you have been following this blog, and have and found it interesting, or want to know more about any of the topics covered here (polar biology, plankton, life in Antarctica), you can

Invite us to your classroom!

Invite us to your classroom!

leave us a message at the bottom of this blog page.  For the educators and classrooms which have been following this blog, let us know if you would be interested in having one of our scientists visit and give a presentation on polar science to your class: we love to talk about our work, and would be thrilled with the opportunity to talk to your students.

So what lies ahead? Our frozen samples arrive next week, and starting in January I will extract the DNA and begin the long process of preparing the samples for sequencing.  Collecting the samples was just the beginning, and we will be processing the samples and data for months to come – keep an eye on this website for periodic updates on our discoveries.

I’ll finish off this post with a picture I took of Castle Rock on our last night in Antarctica. While we were all eager to return home, we hadn’t seen the sun set once in three weeks, and it is moments of sublime beauty like this picture of Castle Rock glowing at midnight which keep polar biologists coming back year after year.  Enjoy!

Castle Rock under the midnight sun

Castle Rock glowing under the midnight sun

Station IV: The Ice Edge

Brian sets up an ice anchor while Jeff Hoffman flakes out a belay rope.  The ice edge is in the background.

Brian sets up an ice anchor while Jeff Hoffman flakes out a belay rope. Jeff and I belayed Brian to the ice edge, where he tested the ice stability.

Our last station in our Ross Sea transect was out at the ice edge, about two miles north of our previous station, Station III.  We were interested to see how plankton in the open polynya were different  from the phytoplankton we isolated from areas locked in sea-ice.  Polynyas are ice-free areas of open ocean and are highly productive, and the photosynthetic activity of diatoms and other phytoplankton of the polar regions are thought to be important components of the global carbon cycle.

the sea-ice thickness where we were working. A weddell seal kep an eye on us while we worked.

The bottom of the sea ice can be seen in this picture. A nearby Weddell Seal watched us.

We left our heavy vehicles at Station III and took lighter snowmobiles out towards the open water. The Ross Sea polynya is one of the largest polynyas in Antarctica, and the sight of open water after weeks in Antarctica’s frozen environment was totally thrilling. Distant pack ice dampened the incoming Southern Ocean swell, so there weren’t large waves breaking over the ice, and in the distance we could see icebergs floating on the horizon. Near the waters edge, we stopped the snowmobiles short and set up a belay station.  Using ropes, we belayed Brian out to the edge of the ice, where he drilled to test the thickness of the ice. The thickness was just over two meter, and if you peered over the edge, you could just make out the underside of the sea ice.  We unpacked our sample gear and Jeff and I started to set up a filtration station.

Emperor penguins pop over the ice edge and toboggan towards us

Emperor penguins pop over the ice edge and toboggan wildly across the slick ice

As we were connecting up our tubing and air compressor, we heard some noise from the ice edge, and suddenly dozens of emperor penguins began boiling up out of the water and landing directly onto the ice.  They landed with big plops on their bellies, and quickly tobogganed away from the ice edge, splashing through the slush and creating a total rucus.  It is doubtful an approaching penguin can see the top side of the ice – they pop onto the ice blind, so standing near the ice edge carried the non-negligible risk of getting knocked over by a 70 pound flying penguin!

Emperors gather as we set up our filter station

Emperors gather as we set up our filter station

We set up our plankton filtration station, and as we worked our audience of flightless birds grew.  Emperor penguins are extremely curious animals, and they fearlessly let us know that we were in their domain.  At times they would waddle around our filters and pumps, silently looking over our set-up and seemingly unperturbed by our noisy gasoline-powered air compressor.

Beach chair moment: Jeff and Brian wait for our filters while penguins walk about and survey our work

Beach chair moment: Jeff and Brian wait for our filters while penguins waddle and survey our work

Other times they would just stand around and preen, and they were an endless source of amusement.  Just as at the previous stations,  we collected three separate samples of plankton. One sample is for DNA shotgun sequencing, which we will use to identify the total complement of  genes present in the seawater: this can almost be thought of as the genomic potential of the system.  Our second sample is mRNA, which is a the total transcriptome of the plankton: this will tell us what genes are actively being used at the time we collected the sample.  We are also taking a third sample for analysis of the proteome, or the protein products of the genome.

Adelie penguins jump onto ice edge and join in the science

Adelie penguins pop onto the ice and join the science

It takes us about seven hours to filter sufficient volumes of water and harvest enough plankton for these analysis, so in the meantime we sat out on beach chairs, kept an eye to make sure our hoses and pumps didn’t freeze, and watched the penguin parade.  Partway through the day a large group of Adelie penguins swam over and joined the scene.  Adelie penguins are significantly smaller than Emperor penguins, so when they emerge from the water, they have so much momentum they literally shoot into the air, landing on their feet before tobogganing to safety.

Eventually it became a penguin party

An Adelie (foreground) and Emperor penguin social

The afternoon eventually devolved into a multi-species penguin party, with the birds occasionally waddling over to our filtration racks to see what the red-jacketed aliens were doing, and otherwise just hanging out together, Adelies and Emperors. We were surprised to see this casual behavior, and there was rarely any hostility between the two species of penguins – though I think I saw an Emperor swat an Adelie out of the way once.

Pair of courting emperor penguins

Pair of courting emperor penguins

Perhaps I’m going a bit overboard with the penguins, but it was truly amazing to watch them while we went about our work, and they generated endless photogenic moments. Many of the emperor pairs were courting: the male stand directly in front of a female, head down, and then slowly raise his head while issuing his song.  The female would follow the motion, until they both held  heads in the air, and they would hold that posture, ostensibly sizing each other up for potential worthiness as a mate.

While we were packing our gear the emperor penguins sensed the show was ove,r and they queued up to return to the sea.

While we were packing our gear the emperor penguins sensed the show was over and they queued up to return to the sea.

Towards evening we finished the last of our sampling, and as we began to unhook the filtration lines and hoses, the Emperor penguins sensed the show was over, and began to queue up on the ice.  After they were all in an orderly line, they tobogganed back off into the ocean, leaving us to pack up our gear and take our samples back to our mobile research sled.  We now had four stations in a transect, starting at land’s edge and traversing out across the frozen Ross Sea to the open water at the Ross Sea Polynya. We were all tired from the effort, and looking forward to some fresh food and heated rooms back in McMurdo Station.

Station III: approaching the ice edge

As we were finishing up our work at Station II, we called MacOps, the radio command center for McMurdo Station, and got a 24 hour weather update: a high to the north of Ross Island was blocking a storm in the south, and we were caught in the middle.  The prediction: snow, and lots of it.  We had already been caught out on two other storms, and so this time we decided to speed up our activities and get to the next station, Station III, before the snow started falling and we got stuck. As we were rushing around to finish last minute experiments, we had some visitors drop by our camp:

Seven Emperor penguins toboggan up to us from the south.  As they get close they stand up and start walking towards our camp

Seven Emperor penguins toboggan up to us from the south. As they got close they stood up and almost walked right into camp

The Emperor penguins get together and 'conference' about these strange red-jacketed aliens who have landed on their sea-ice.

The Emperor penguins get together and seem to conference about the intentions of these strange red-jacketed aliens who have landed on the sea-ice.

Eventually they decide we aren't all that interesting, and they walk on, seemingly deep in thought

Eventually they decide we aren't all that interesting, and they walk off to the north

We continue with our packing, and soon we are able to hitch up our vehicles and sleds and continue heading west, out across the McMurdo Sound.  At first the sea ice was similar to the day before: lots of cracks and pressure ridges where the plates collide, all of which need to be checked out before we can safely pass.  About half way there though, the sea ice becomes smooth, and the cracks become so small that none if them are wide enough to present a possible danger.

Jeff Hoffman and Abigail Noble set up tents

Jeff Hoffman and Abigail Noble set up tents

We get to camp, and when we climbed on the roof of our research sled, we could actually see the open water of the Ross Sea Polynya about two miles to our north.  It was an amazing, and heartening sight, and we were excited to start seeing changes in both planktonic organisms and in water chemistry. As before, we arranged our vehicles in a windbreak, hoping to block the winds from the south, and had a quick hot meal before we got down to the business of prepping filters, drilling holes and labeling our collection tubes.

Jeff McQuaid collects some cores, with the skies darkening to the north

Jeff McQuaid collects a core while the skies darken

We are almost falling into a routine: I start working with the Kovacs corer while Mak and Abigail prepare the winch and tripod for casting the Niskin bottles.  This particular station is over 700 meters deep, so lowering and raising a bottle 2000 feet will take some time.  We had been using a HotFinger to melt and widen holes in the ice, but one of the connectors broke, so now Mak isn’t able to circulate hot glycol through the coils.  He and Matt end up using the one of the large drills, which take two people and are extremely heavy. I start pulling up a number of cores, and notice that there is less coloration that the previous site, which was less than the first station.  We wonder if this is a trend as you move away from land, and consider whether we will have time to head back and take a few additional cores for comparasion. As we are talking about maybe using the snowmobiles to do this, we get seven more visitors, this time from the polynya to the north:

Seven Adelie penguins approach from the waddle up from the north

A group of Adelie penguins waddle up from the polynya just north of camp

These Adelie penguins are not even a quarter of the size of the Emperor penguins we had seen earlier in the day, and unlike the stately and seemingly introspective Emperors, the Adelie seemed comical, almost borderline ditzy.  The walked around camp, looking at our equipment, and they seemed pretty oblivious as they horsed around before headed back out to the polynya.

Abigail adjusts the rope on the Niskin Bottle winch as the storm develops

Abigail adjusts the rope on the Niskin Bottle winch as the storm develops

The snow started to fall, and the winds picked up – it was time for another Antarctic storm!  We were only partway through sampling, but we needed a few critical pieces of equipment, including a snowmobile sled and a portable rack: as our last sample, Jeff Hoffman and I wanted to get up to the ice edge and sample the open polynya water, and to do that we would need more portable gear.  It was decided I would go back in a Pisten Bully with Matt and try to beat the storm, and come back in the morning with our equipment. So I got a night in town – and a chance to post another update to the blog! Tommorow Jeff Hoffman and I will continue our transect right up to the sea-ice edge, which should be spectacular – stay tuned!

Station II, Inaccessible Island

Our vehicles at Station I (near the center of the photograph)

Our camp at Station I (near the center of the sea ice field)

The second storm of our trip hit us while we were packing up Station I for a return to McMurdo.  The winds began gusting over 50 miles per hour, and the visibility dropped to near zero.  We had already packed up camp, but the orders came in over the radio that Condition 1 had been imposed on the sea ice route, and we were stuck there until conditions improved. Three of us slept on the floor of the research sled while Mak and I slept in the back of the Pisten Bully.  The wind shook and buffeted the vehicle all night, and at times the Pisten Bully made this vibrating sound like we were just about to take off.

Testing ice thickness at a buried sea-ice crack

Matt drills to test the ice thickness across a crack

But by 6 PM the following day, the visibility had improved enough for us to follow the flags along the sea-ice highway and return to McMurdo.  In town we picked up another crewmember: Matt Smith, the sea-ice specialist for the US Antarctic Program in McMurdo.  We then drove back out to our camp at Station I and spent several hours digging our vehicles out of the snowdrifts. By noon the following day everything was ready again for redeployment, and we set out across the ice for our next station, on the north side of Inaccessible Island.

Weddell seals lounging on the ice are a warning sign for potential cracks

Weddell seals on the ice are a good indicator for nearby ice cracks

The fresh snow had buried many of the obvious ice cracks and features, so Matt and I went ahead on snowmobiles to scout the route while Jeff Hoffman and Mak Saito followed with the sleds.  Cracks like the ridgeline in the above photo were relatively easy to spot, and we drilled them to make sure they were a meter thick, which is more than enough to support the weight of our vehicles.  Other cracks though were less apparent, but many times those cracks were given away by the presence of seals loafing on the ice – the pup in this picture barely even moved as we rumbled by, and we saw his breathing hole in a hidden crack just a few feet away. We gave that area wide berth.  After a few hours of crack testing and route finding, we made it out into McMurdo Sound proper and to our next station.

An ice core showing the diatoms growing on the bottom of the sea ice

An ice core showing the diatoms growing on the bottom of the sea ice

The next morning we fired up our generator and drills.  I used the Kovacs core sampler to create a large enough hole so that Jeff and I could get our sampling gear down below the ice.  We have been wrapping all of our sample tubing in black insulation, as the seawater will rapidly freeze on contact with icy air.  This is espeically true in Antarctica, where the wind seems to blow nearly continuously, freezing engines, air hoses, compressors, you name it!  I also drilled a number of ice cores so we could obtain some genetic material from the organisms living on the bottom of the ice.  Drilling those cores takes a few hours- while I was doing that Jeff Hoffman worked the stainless steel Jeff Hoffman high biomass filterfilter sets and the viral concentrator. In the picture on the left you can see one of the filters for the larger phytoplankton.  That particular filter captures anything in the water which is between 3 and 200 microns, which is the size of most of the diatoms and other large phytoplankton.  If you have a sharp eye, or a good computer monitor, you can see a slight discoloration of the filter as compared to the edge – that discoloration is from planktonic cells which have become trapped on the filter.  To obtain that amount of cells, we had to filter over 400 liters of seawater, and even then, it almost seems less that the amount that was in the ice core. This is possibly due to seasonality in the sea-ice cycle: it is still late spring here, and as summer progresses and the sea ice starts to melt, the diatoms trapped in the sea ice will be released into the water, becoming the seeds for the annual summer phytoplankton bloom in the Ross Sea. Jeff Hoffman and Andy Allen brought back samples last year from the late summer, so between the spring and summer samples we should be able to develop a wider genomic understanding of polar marine phytoplankton.

Sea-ice camp at Station II. We used the sled and the vehicles as wind barriers     Taking a break and having some hot beverages at our sea-ice camp at Station II.   We used the sled and the vehicles as a windbreak in case the weather changed.

Enjoying some hot beverages out of the wind at Station II ice camp

McMurdo Sound

Winching our Pisten Bully out of a deep snowdrift

Winching our Pisten Bully out of a deep snowdrift

It took another day for the storm to blow itself out, but by Tuesday the wind and driving snow had abated, and we drove our Pisten Bully back out to our temporary shelter near Cape Evans.  It took several hours of digging to clear the snow away from our vehicles, but once we started driving away from the hut we quickly ran into another problem: the snow was so

Using a Kovacs drill to obtain an ice core

Jeff McQuaid using a Kovacs drill to obtain an ice core

deep that our sleds and vehicles would bog down in the snowdrifts. Often we would pull out the Pisten Bully, only to have the Sno-Cat get stuck and have to dig that out.  An entire day went by digging vehicles out of the snow, and in the process we broke our sled hitch and winch.  Eventually we were able to drag our research sled to suitable location for obtaining a sample of plankton, and we set up camp.

We first tested the ice thickness at our sample site using a standard ice drill – we needed three drill extensions, or drill flights, to get to the bottom of the sea ice, which meant using an awkward 100 inch drill.  The ice were we were stationed turned out to be 78 inches thick.  We then used a Kovacs Mark II coring drill to obtain a 4 inch diameter core of ice.  The sea ice is remarkably consistent, until you approach the bottom layer, where diatoms and other phytoplankton have entrained themselves in the ice. By keeping to the

An inverted ice core showing the mass of phytoplankton growing on the bottom of the ice

An inverted ice core showing a layer of phytoplankton growing in the sea ice

underside of the ice, microscopic plankton are the first organisms to intercept light as it enters the ocean, but the plankton are still close enough to the unfrozen seawater to obtain dissolved nutrients and minerals.  Living in the ice also protects the phytoplankton from grazing zooplankton like Antarctic krill.  We took the core on the left, removed the brown layer containing the diatoms and other phytoplankton, and carefully preserved the cells in liquid nitrogen for sequencing at the J. Craig Venter Institute.  These diatoms probably function very differently from diatoms living in the water, so sequencing their mRNA transcripts (or transcriptome) will tell us what kinds of proteins they make and how they function in a frozen environment.

Jeff Hoffman runs the filtration statoin inside our research sled

Jeff Hoffman runs the large steel filters for separating the phytoplankton by size

Once we have a clear hole in the ice we begin pumping seawater through a series of filter discs so we can separate the plankton based on their size.  Our first filter is a 200 micron pre-filter on our sample tube – this keeps us from pulling zooplankton into our filters (we are mostly interested in the primary producers, the microscopic phytoplankton).  The first filter is 3.0 microns, and intercepts the large eukaryotic phytoplankton.  The second filter is 0.8 microns in size, and intercepts smaller picoplankton and some prokaryotic bacteria and archaea.  The last

Mak Saito monitoring the winch and tripod

Mak Saito monitoring the winch and tripod. The wind picked up as the day progressed

filter is the 0.1 micron filter, and the organisms entrained here are almost exclusively prokaryotes. Before the seawater is returned below the sea ice, it is passed through a 50 kilodalton tangential flow filter: this last filter will remove and concentrate marine viruses, which may have a large effect on the function of the marine food web. In Antarctica, we are passing several hundred liters of water through the filters at each station, and usually in triplicate, which can take us most of the day.

Dawn's corner: culturing marine organisms and measuring particulate carbon

Dawn's corner: culturing marine organisms and measuring particulate carbon

On station, our group had different tasks to do: Jeff Hoffman worked the internal pumps and filters, while I took ice cores and kept the external machinery running.  Mak Saito (pictured above) used a winch to deploy nansen bottles down through the water column and collect water from discrete depths: at our particular station, the water was 182 meters deep.  The water Mak collected was passed along to Dawn (on right), where some of the water was filtered for particulate carbon analysis.  Dawn also worked on culturing out organisms from the various samples as they arrived. The bulk of the water from the Nansen bottles went to Abigail Noble, where

Abigail in the clean room for trace metal analysis

Abigail in the clean room for trace metal analysis

she took them into her clean room for trace metal analysis. Because dissolved metal concentrations are so low in the ocean, all analyses have to be done in a controlled clean room: even a speck of dust could potentially alter her final concentrations. Abigail had a laminar flow vent leading into a plastic bubble-wrapped enclosure, and she even wore trace-metal clean slippers while inside. It was a sophisticated operation for a sled out on the sea ice!

We worked through the evening, and by midnight we were ready to wrap up our operation and head back to McMurdo Station.  Mother nature had a different idea though: as we were leaving, the winds picked up, and began gusting over 50 knots, while the blowing snow caused the visibility to drop. McMurdo operations informed us that the weather had just deteriorated again, and was Condition 1, meaning no travel whatsoever.  We were pinned down by yet another Antarctic storm!

Digging out from the storm

Our Sno-cat tucker gets drifted in

Our Sno-cat tucker gets drifted in (Photo AN)

The next day offered more snow and wind: we still needed handheld radios anytime we ventured between the warming hut and any of the vehicles.  The wind was so strong that snow began drifting up through the dive hole in the warming hut, and the windows completely glazed over with snow.  At one point Abigail ventured out with her camera, so follow this link if you want to experience a condition 1 Antarctic storm from the safety and comfort of your chair. Needless to say trips outside were kept to a minimum, and we were sure to keep hot chocolate and coffee at hand.

Mak and Jeff prepare to lower a sediment trap

Mak and Jeff lower the sediment trap (Photo DM)

So even though it was a day stuck indoors, there was plenty of science to do, and we considered it an incredible stroke of good luck to be stuck in a hut with a convenient access hole to the Ross Sea! Dawn was able to pull some plankton from the sea ice and view them in the ambient light of one of the windows. Abigail’s focus of research is metal chemistry in the marine environment, and she was able to do some prep work, soaking and treating all of her Nansen Bottles to remove any traces of contaminating metals.  Metal concentrations in seawater are notoriously difficult to quantify as all of the tools we use are contaminated with metals, including the plastic bottles and lines used to deploy them.  Soaking them in seawater for 24 hours will mitigate the problem, so we lowered them below the sea ice.

Deploying the sediment trap below the ice

Deploying the sediment trap (Photo DM)

Mak Saito also brought his custom-made  sediment trap, and this too was deployed for a 48 hour incubation below the ice.  Sediment traps are particularly important tools in oceanography, as they help scientists quantify the flow, or flux, of dead and dying plankton from the sruface to the ocean depths.  As plankton sink, they are effectively removing organic carbon and nutrients from the ocean surface, so understanding this rate has important implications for the speed at which carbon is removed from the atmosphere and sequestered in the ocean depths.

It also turned out that the dive hole was not a one way street: throughout the day Weddell seals would use the hole in the ice as an access point for air. Weddell seals are master divers, and they can dive up to 700 m (2100 ft) deep, and they can stay underwater for over an hour as they search for fish, squid and krill. When they would pop up in our dive hut, they seemed very keen for air, and they would spend a full minute hyperventilating to clear the carbon dioxide out of their lungs before disappearing back below the ice.

Dawn shoveling a path to the mobile lab

Dawn carving a path through the drifts to our mobile lab (Photo MS)

Eventually the storm slowed down enough that we could start to dig ourselves out.  There was still snow blowing down off of the Erebus glaciers, but by our third day in the hut, visibility started to improve enough that we could shovel path and clear vehicles.  Dawn and Abigail cleared a path to our lab sled while Mak, Jeff and I cleared away the generator and transferred fuel to the Pisten Bully. I was also able to use the Iridium satellite phone to get a call out to my wife, who is currently in Bukhara, Uzbekistan: making a call from a fish hut in Anarctica to a 14th century silk road city is a really mind-bending use of technology!

Digging out our generatos so that we can charge up the Pisten Bully (Photo MS)

Digging out our generator so that we can charge up the Pisten Bully (Photo MS)

The Pisten Bully needed to be warmed for two hours before we could start it up, but once it was running we decided to head back to McMurdo while the weather was good.  We has GPS coordinates to get us back to the Cape Evans sea ice road, and from there it was relatively easy to follow the flags back to McMurdo Station.  On Monday we will head back out, and so hopefully our next post will be from station one. Until then  —  keep warm!

Out onto the ice

Our vehicle train leaves McMurdo Station under a bright blue sky

Our vehicle train heads out onto the sea ice under a bright blue sky (Photo JH)

It took an enormous amount of effort, but on Thursday we ventured out onto the sea ice with our train of sleds and snow machines.  The tucker is our strongest (and slowest) vehicle, and it is pulling both our yellow research sled and a pair of snowmobiles.  The red Pisten-Bully is pulling a second sled with several drums of diesel, a generator and assorted science gear.  The weather was clear, cold and windy, with snow in the long-term forecast.

Leaving tracks across the snow as we leave the sea ice road (Photo: AN)

Looking out the rear window as we leave the sea ice road and enter deep snow (Photo: AN)

Initially we followed the Cape Evans sea ice traverse out of town: this route is a flagged and reconnoitered sea ice ‘highway’, so we were able to travel at maximum speed without having to stop and check the thickness of the ice.  (Note that ‘humming along’ in Sno-cat is going about 3 mph).  After two and a half hours on the sea-ice highway, we turned off the traverse and cut fresh tracks across the snow towards Inaccessible Island. The island is a big hunk of basalt rising straight out of the Ross Sea, and as we rounded the tip of the island, we saw a line of Weddell seals stretching off into the distance, evidence of large cracks in the ice.  We tested a number of possible routes through the area, but all of the cracks were too wide and thin to safely cross.

Warming hut at the Cape Evans wall

Warming hut behind Cape Evans (Photo: AN)

We followed our tracks back to the sea ice road and continued north, passing around the other side of Inaccessible and trying our luck north of some large grounded icebergs.  Here there were fewerbseals, and  sea ice was more uniform, but we still ran into several large cracks, and by the time we had surveyed our route, it was past nine in the evening, and we needed to consider setting up camp.  The wind had picked up noticeably, so we decided to head back towards Cape Evans and get some shelter from the coming storm.  We were located near the hut that Robert Scott built for his 1911 Terra Nova expedition to the South Pole, but spending the night in the area is discouraged, as the area is a world heratige site.  McMurdo Operations alerted us to a warming hut located behind Cape Evans, sheltered from the continental wall by a glacier on one side and a large basalt wall on the other.

Dawn and Jeff wondering what is down in that dive hole (Photo AN)

Dawn and Jeff wondering what might live down in that dive hole (Photo AN)

The hut turned out to be a dive shack kept heated to prevent the dive hole from freezing over. This presented some hazards when walking around the hut – one of the first casualties was my camera, which tipped out of my pocket and is now somewhere on the bottom of the Ross Sea.  Still though, it was far better than being camped out on the unprotected sea-ice and blasted by wind, so we brought in folding chairs, sleeping bags and a portable kitchen, prepared to hunker down while the storm passed.

The storm hits our warming hut

The storm hits our warming hut

And what a storm! I grew up in rural New Hampshire and lived in Siberia, so I’ve experienced my share of foul weather, but there is nothing like a Condition 1 Antarctic storm to give you new respect for the raw power of nature. The visibility progressively dropped and the sky darkened, and the snow began to fall.  It became impossible to tell whether the snow was actually falling or just blowing off the glacier, and the hut shook in the gusts. We had good radio communications with McMurdo Station, so we were never in danger, but we were certainly not going anywhere anytime soon – Hut 12 was our new home.

Around Mac-town

Getting supplies at the Berg Field Center

Getting supplies at the Berg Field Center

We are now fully packed and our mobile research sled is ready to go. We are waiting for some final repairs on the Pisten-Bully which will pull our supply sled.  The mobile laboratory sled will be pulled by the Sno-Cat Tucker, which also has cab space for six (riding in the mobile lab would probably be too bouncy). At 8:30 this morning I went to the Berg Field Center (BFC) to plan out all the food for the expedition.  The BFC is well stocked, and I I was able to find lots of high energy food: pasta and sauces, rice pilaf, couscous.  I also went heavy on the snacks, as you can’t have too many calories when you are living on the sea-ice: cookies, crackers, granola, Cadbury bars, energy bars, gorp, you name it! Most importantly I picked up a bunch of hot drinks and instant soups, as a cup of tea or a bowl of soup can really make a difference in keeping you warm.

Comfort Zone: the upstairs loft of the Berg Field Center

Deep in the Comfort Zone: the upstairs loft of the Berg Field Center

After packaging all of our food I went over to the equipment loft and picked up extra camping equipment. We will be sleeping on the ice, so I grabbed some extra mattress pads, and also found some low-profile tents which (hopefully) won’t blow away in the wind. The equipment area really is an oasis: the staff are super organized and friendly, and there is always great music playing.  And it smells of wood (most of McMurdo Station generally smells more like machinery).

A pile of Nansen sleds next to the Berg Field Center

A pile of Nansen sleds next to the Berg Field Center

As I was leaving the Berg Field Center I saw a pile of old Nansen Sleds.  I always associated Fridjof Nansen with the Nansen Bottle, which is arguably one of the key inventions of modern oceanography – I didn’t know about the sled. Nansen was a colorful explorer and inventor, and his Wikipedia entry is well worth a read. Unfortunately we won’t be using the Nansen sleds… maybe next trip.

The only espresso in town: the McMurdo Coffee House

The only espresso in town: the McMurdo Coffee House

Much of the rest of the afternoon was spent running errands around McMurdo, or ‘Mac-town’: I filled our water carboys, went to the gas station and filled 10 jerry-cans with 50 gallons of fuel, and shuttled science gear down to the sled using a borrowed truck.  I’m getting to know McMurdo better, and by walking around so much, I find all kinds of interesting places.  On the right is the McMurdo Coffee House, the only place in town to get an espresso. The coffee house is a great place to come in from the cold, especially when you are waiting for the science delivery truck to free up so you can borrow it again.

Church of the Snows

Church of the Snows

McMurdo has all kinds of amenities: there is a radio station, a barber shop, a store, two bars, library and a post office.  There is a church (pictured on the left), a gym, and there was even a bowling alley (it was structurally unsound and had to be closed). For entertainment there are classes, clubs, and movie nights.  Every Wednesday and Sunday there is a science lecture series, and anyone can go and hear about all of the interesting science which goes on in Antarctica.

Well, I will sign off for now.  Tomorrow morning we will begin our trek across the ice, and I should get some sleep and be fresh for the day.  Our router and internet antenna were installed this afternoon, so my next posting should be from somewhere on the McMurdo Sound sea ice.  Tomorrow’s forecast: mid-teens, light snow, reduced winds.  Great weather for phytoplankton research!

Ice diatoms!

Last-minute adjustments to our mobile science sled

Last-minute adjustments to our mobile science sled

Today has been a day of preparations, as tomorrow we hope to leave McMurdo Station and head out on the sea ice.  Our mobile sled is almost ready for deployment: the carpenters who work for the US Antarctic Program are quite amazing, and our sled has filtration racks for separating different sizes of plankton,  incubation chambers, and a mobile clean room for trace metal analyses.  All of this in a 6 x 12 foot space!  I’ll have more photographs in the posts to come, but it very much a sled of the 21st century.

Dawn and Abigail check out the tents at the Berg Field Center

Dawn and Abigail check out the row of Scott tents available for check-out at the Berg Field Center

We are also assembling our equipment list for camping on the ice, and the list is impressive: tents, coleman stoves, fuel, kitchen boxes, ice screws, shovels, jerry cans, carabiners, spare sleds, and a hurdy gurdy. Don’t ask me what that last thing is, I’ve been told it is a ‘fuel transfer unrelated to the musical instrument. The place to get all of these items is the Berg Field Center, which is a storehouse of mountaineering and back-country equipment available to all scientists doing Antarctic field work.  For someone who likes mountaineering as much as I do, visiting the Berg Field Center is like letting loose a kid in a candy store – the place just oozes exploration.

Dawn and Mak learn about drive belts

Dawn and Mak learn about drive belts and engine parts

In the afternoon our group attended a class on snowmobiles use and maintenance.  Our research sled will be pulled by a Tucker Sno-Cat, and our lighter open-air equipment sleigh will be pulled by a Pisten Bully.  Both of these machines are major workhorses in and around Antarctica, but they are slow: the Pisten Bully moves along at 6 mph. So for added flexibility we decided to bring along a pair of snowmobiles.  With snowmobiles, we will be able to ride ahead and scout for hazard on the ice, as well as run back to McMurdo to pick up extra equipment or drop off samples. Driving a snowmobile is similar to riding a motorcycle, although the snowmobile doesn’t have any real gears, and snowmobiles  reek of partially burned fuel (dirty two-stroke engines).  As part of our training we ran a mogul course, and learned how to ride on ice and on slopes, and now I understand we are all certified ‘snow machine technicians’.

Diatoms growing in the ice

A layer of plankton growing in the sea ice

Hard to believe, but in between training sessions and lab set-up, Dawn has been able to have a look at some of the diatoms that Abigail and I brought back from our sea-ice training (see yesterday’s blog).  On the right is a picture of a piece of ice from one of the holes we drilled when we were determining the thickness of the ice in cracks, and you can see that there is layer of ice discolored with pigment.  These are microscopic plankton living in the ice, and for something non-mobile, living in the ice is ideal in some ways. Plankton embedded in the ice are protected from being eaten by krill and other grazing zooplankton, and ice plankton are also at the top of the water column, so they receive maximal sunlight.  We transported our samples of ice back to the lab, and Dawn was able to put them under a light microscope with a camera attached and generate this picture:

Ice Diatoms: chain forming fragilariopsis (center) and ribbons of Amphiprora (squares with oval centers), with colonies of Nitzschia (long thin ovals growing end-to-end)

Ice Diatoms: chain forming Fragilariopsis (center), ribbons of Amphiprora (squares with oval centers), and colonies of Nitzschia (long ovals growing end-to-end)

These are all diatoms, and not only could Dawn identify all of them without a guide, she could correctly spell them.  Diatoms are glass shelled plankton famous for having some of the most beautiful patterned shapes in the ocean (see an SEM image here to get the idea).  Diatoms play a vital role in the global carbon cycle, as the they remove large amounts of carbon dioxide from the atmosphere before dying and sinking to the bottom of the ocean.  Large blooms of diatoms and other plankton may ultimately help remove much of the greenhouse gasses resulting from fossil fuel use, and is only one of many reasons why we are down here studying them.