Tuesday, February 6, 2018

Between two lungs

"Gone are the days of begging
The days of theft
No more gasping for a breath
The air has filled me head to toe
And I can see the ground far below
I have this breath and I hold it tight
And I keep it in my chest with all my might
I pray to God this breath with last
And it pushes past my lips
As I gasp"
- "Between two lungs" by Florence and the Machine

I love the air at the poles. 

Photo by Tess Cole
I realized it on my first Arctic expedition in 2011. I was standing on the bow of the icebreaker Polarstern, gazing out to the horizon and feeling the wind on my neck. I breathed deeply and relished the feeling of a thousand icicles filling my lungs. I think that was the day I fell in love with the Arctic. Cold air makes me feel clean from the inside out. 

When I was little, my doctor used to say I had "tricky airways." I don't know exactly what he meant by that because he never diagnosed me with asthma, but every cold I got turned into bronchitis. I remember feeling the tightness in my chest whenever I was sick, and I couldn't blow up a balloon until I was in my twenties. 

These days, my affinity for polar air is not physiological, it’s psychological. My lungs have long outgrown their childhood restrictions, so it is my mind that relishes the cold. When I breathe in the crisp, dry air, all traces of stress vanish from my psychi. I feel clean and empowered and new. I relax – which says a lot, because polar regions pose countless logistical difficulties to research. I have run into roadblocks and seen missions aborted. I have struggled against bad weather and transportation snafus. But in the end, the mountains, the wildlife, and the snow-draped landscapes - even the gale-force winds on bad weather days - all enthrall me. They elevate my soul. My heart lives at the poles.

My time at McMurdo Station is drawing to a close, but I can tell you this: I will return. As soon as I get home, I will begin reading and researching and shaping a project that will carry me back here. Antarctica is the coldest, driest place on Earth, and I honestly thought I would have to wait many more years - decades, even - before I ever made it to the southern continent. I am grateful beyond measure for the chance to experience Antarctica and get a foot in the door with the U.S. polar community. This month has been an incredible adventure. There are so many unanswered questions I want to pursue at the bottom of the world, and I am determined to return to this captivating place.

Standing in the middle of the ice shelf, I scan the mountainous horizon one last time. I draw my last breath of the cold polar air and hold it in my lungs. And I walk up the steps into the plane.

Monday, February 5, 2018

Groundhog day

"You want a prediction about the weather?...I'm going to give you a prediction about this winter. It's going to be cold, it's going to be dark, and it's going to last you for the rest of your lives." 
- the movie Groundhog Day

I looked up from my plate of eggs and fruit at Mark. He was wearing a blue-and-white shirt with a vest, much like the day before. I adjusted the neckline of my sweater, which I had also been wearing the day prior. Here we were again, having breakfast, checking the flight schedule. I had the strange feeling that I was living the same day over again.

The Antarctic training course is over, but our group has been detained on the ice. First the weather was bad, then the flights were backed up because of the weather delay, then the weather got bad again. We've been delayed for three days. Having already checked our luggage for the flight, we're also living with limited outfit options. Each day is déjà vu. 

It's not unusual to be delayed getting on or off the ice, and the military pilots who fly us know what they're doing. In the meantime, I appreciate the chance to rest. We'll be heading out soon. 

Wednesday, January 31, 2018

Cape Evans

"For scientific discovery, give me Scott; for speed and efficiency of travel, give me Amundsen; but when you are in a hopeless situation, when you are seeing no way out, get down on your knees and pray for Shackleton." - Raymond Priestley

The Terra Nova hut, at Cape Evans
Friends, when I quoted the above sentence to you before, I did not give you the whole thing. There is a third famous Antarctic explorer: Ernest Shackleton. Irish by birth, he served in the British Navy and lead several Antarctic expeditions. Like Scott, he saw hard times on the southern continent, but unlike Scott, Shackleton was renouned as an effective leader and strategic thinker. His famous Endurance expedition to cross Antarctica was plagued by a series of unfortunate events, but his entire expedition team survived (unlike Scott). In fact, when Shackleton's resupply team was stranded in McMurdo Sound, he returned personally to save them, despite having just finished a horrendous journey himself.

The Aurora anchor
Cyanobacterial mats at Cape Evans
Shackleton began his trans-Antarctic expedition from the Weddell Sea, on the Atlantic side of the continent, while his resupply team started from the Ross Sea, on the Pacific side. They were supposed to meet at the South Pole. The stranded members of the resupply team never made it, though, and actually lived for two years in McMurdo Sound, at a site called Cape Evans. The site has a hut that had been built by Scott years before, where the men were able to take shelter and await rescue. Before you go imagining an icebox of a house like Discovery Hut, I'll tell you that the Terra Nova hut at Cape Evans was meant to be lived in, and it is actually quite cozy. My fellow trainees and I got to tour the hut during a sampling trip to Cape Evans, and it is a place I would have gladly lived.

It's a wooden house with a gas heating stove, a kitchen, and cots. There was a stable just outside, where Scott kept his ponies. Despite its apparent comfort, the hut still bears the evidence of difficult times: the anchor to the the Aurora, Shackleton's resupply ship, tore away from the ship (that's how the men got stranded ashore) and still lays buried in the gravel outside the hut. Inside the hut are old piles of seal skin and penguin eggs - remnants of the marooned men's hunted food sources.

Barn Glacier
Besides the historical hut, Cape Evans is an interesting site for biologists to visit. Extensive areas of bare gravel serve as nesting sites for the Antarctic skua, a scavenging sea bird. The heterogenous terrain has depressions that fill with melting snow and host thick cyanobacterial mats. Also known as blue-green algae, cyanobacteria are single-celled microbes that photosynthesize. They're responsible for producing much of the oxygen you breathe. The mats were green and orange and yellow and floated on top of the melt ponds. It was very cool to see.

Me at Cape Evans. Photo by Tess Cole.
We spent several hours at Cape Evans, hiking to the melt ponds, touring the hut, and exploring the surrounding area. The nearby Barn Glacier dominates the northern horizon, and Inaccessible Island towers to the south. Mt. Erebus overlooks Cape Evans from the east, and the ice-covered McMurdo Sound stretches to the west. It is a gorgeous place.

The good news for me is that Cape Evans is also a common dive site for Antarctic research. I'm told it's a particularly good site to collect sea urchins. Note to self: design a project on Antarctic sea urchins. I hope I get to come back!

Tuesday, January 30, 2018

Ice edge

I heard the reaction before I heard the blast.
The sea ice edge (and a helicopter blade)

"Whoa!" exclaimed Chelsea, leaning back in her thick blue coat and raising her camera to her eye. Then I heard the rush of air as the whale breathed behind me and turned around to catch its dorsal fin disappearing below the sea surface. The large gray minke whale was about 10 m away from me.

I was standing on a shelf of sea ice. Below me was the Ross Sea, stretching 600 m to the seafloor beneath my feet. Behind me, the white, snow-covered ice shelf ended abruptly and gave way to the deep blue of the ocean. We were at the ice edge collecting samples.

Mt. Erebus and the sea ice edge
The sea ice edge is a very interesting place biologically. The ice acts like a blanket on the ocean, dampening waves and maintaining a stable water column. Phytoplankton bask in the sunlight in the stable water and grow like mad, providing a key energy source for krill and pteropods. The abundant food sources attract whales and fish that gorge on these tiny creatures. Penguins swim in the sea, chowing on fish. Orcas hang around hunting penguins. It's one massive party of a food web.

Adelie penguins and the Transantarctic Mountains 
And it is absolutely stunning. I wish I could have just stood in the middle of the ice and spun around like Julie Andrews in The Sound of Music. My view was flanked by Mt. Erebus on one side and the Transantarctic Mountains on the other. The vast white carpet of sea ice reached back toward land, and in the other direction was the endless deep blue of the Southern Ocean.

We drilled a series of holes in the sea ice to lower instruments through and then approached the edge itself. As a safety precaution, two mountaineers assisted us by drilling ice screws into the ice and attaching belay ropes. Each of us wore a climbing harness and was clipped into the belays so we couldn't fall over the edge. We deployed plankton nets and a CTD (conductivity-temperature-depth gauge), trying all the while not to be distracted by the beauty around us. At one point, as we were pulling up the CTD, a group of Adelie penguins jumped into the water from a nearby icy outcrop and began porpoising, jumping out of the water like dolphins. I held the CTD line firmly in one hand, lifted my head, and stared in awe at the quirky, tuxedoed creatures swimming with perfect grace.

As I climbed back into the helicopter, I could not help but take one last look around me. The ice edge really is a magical place.

Monday, January 29, 2018

Castle Rock

Days off aren't common in the field, but we got one this weekend. I used it to hike a loop trail near McMurdo Station. The trail goes past a steep formation called Castle Rock, then swings out with overlooks to the Ross Ice Shelf. I'll let my photos speak for themselves - it was a beautiful hike!

The Castle Rock Loop trail is marked by flags on the snow

There are emergency shelters called "apples" along the trail.

Castle Rock

With my fellow trainee, Tess, on the trail. We were in a large group, but
most people turned back to the station after seeing Castle Rock. We were
the only two who did the whole loop. 

View out to the Ross Ice Shelf
Mt. Erebus was shrouded in clouds and only partly visible from the trail
A gorgeous ice formation on the Ross Ice Shelf

Saturday, January 27, 2018

Surprise squiggles

Friends, science is a process. It is a journey with plenty of twists and turns, and sometimes, if you're lucky, science has squiggles.

I've told you that the trainees in my program have split into small groups to pursue research projects at McMurdo Station. My group played around with scallop byssal threads and then settled on pteropods for our study organism. In the spirit of integrative biology, we have studied multiple aspects of the pteropods. We have observed them swimming and measured their metabolic rates. We have examined their responses to different temperatures. We have investigated the bacterial communities that live in their bodies.

Fluorescent squiggles on our microscope slide
You may not know this, but most animals host large and diverse communities of bacteria. These microbes aid in digestion, provide chemical cues, and live in harmony with their hosts. In fact, animals can be considered microbial ecosystems.

Our group used a fluorescent stain named DAPI to visualize the microbes that live on and in our pteropods. DAPI makes the bacterial cells glow blue when exposed to light, and the resulting pattern is a series of blue dots on a black background. When we put the slides on the microscope, we did see the dots as expected, but we also saw squiggles.

Our best guess right now is that the squiggles are also bacteria. Cells come in different shapes, and spiral-shaped bacteria exist. The squiggles are probably spiral-shaped cells viewed in a 2D environment.

What's cool about the squiggles is two-fold: first, they were an unexpected shape of cell to find, and second, they were only present in samples from the pteropods. Our group has sampled microbes from amphipods, and other groups have gotten bacteria from other organisms as well. None of the samples have had the squiggles, but all of the pteropod samples have had squiggles. The spiral-shaped bacteria seem to be exclusively associated with pteropods.

The spirals were an exciting and unexpected discovery. A pteropod-bacterial relationship might be an exciting topic to pursue in future research projects!

Friday, January 26, 2018

Long live polar invertebrates: part 2

I dipped the edge of the petri dish into the beaker of water, then pulled it back to find I had successfully caught two amphipods. They were small, red, and bug-like, zooming around the cold water in the dish. I had a hard time focusing on them because they were moving so fast, but thankfully, the speedy swimmers slowed down once they were under the lens of the dissecting microscope. I pulled my chair up to the scope and gazed down through the eyepieces. I had to find out what the little bugs were.

I always take for granted that other scientists know invertebrates, just because I spend so much time around those who do. The group of trainees in my Antarctic program encompasses a diverse array of specialties, from physiology to microbiology to planetary science, so obviously not everyone is as excited about invertebrate zoology as I am. I have been able to help others identify the organisms from McMurdo Sound, and if you don't mind, I'd like to introduce you to a few of them.

Orchomenella pinguides, an amphipod in McMurdo Sound
Amphipods are common in a lot of marine habitats, from the poles to the tropics and from the coast to the deep sea. They're crustaceans, related to crabs and shrimps, but they look more like insects. I vividly remember catching amphipods in Svalbard back in 2015, and they were the most common organism we caught on a cruise to hadal trenches (the deepest part of the ocean) in 2013. Many amphipods are scavengers, so they're easy to catch with baited traps.

At the beginning of our training program, we actually had a very hard time catching amphipods. We put out plastic traps baited with raw fish on the seafloor under the ice in McMurdo Sound, but these tried-and-true methods weren't working. Eventually, someone suggested we put the traps at a range of depths, from the sea ice down to the seafloor, and when we checked back later, only the traps right up under the sea ice had caught amphipods - not what we had expected. The bottom of the sea ice can in many ways be considered an "inverted benthos" - like an upside-down seafloor, with lots of algae growing and animals feeding. There are amphipods in the Arctic that live right up under the sea ice for all or most of their life, but nobody in our group knew that Antarctic amphipods lived there too. It was an exciting discovery!

Another animal we caught in the baited traps were nemerteans, also known as ribbon worms. When my fellow trainees came back from the ice with the worms, they asked me to identify them, so I picked up the long, flexible, tube-like organisms in my hands. It only took a few minutes before my skin was covered in mucus, and I found at later that the nemertean's mucus is acidic, with a pH of 3.5. The mucus, plus the worms' size, flexibility, and the fact that they had been caught in a baited trap made me think at first that they were hagfish, but they didn't look quite right. As I turned over the brown worm, I could see a small opening on the underside near its head. I remembered that ribbon worms have a proboscis that shoots out to catch food, and the opening for the proboscis was on the underside of the head. The worm must be a nemertean!

Parborlasia corrugatus in the respirometer
Its scientific name is Parborlasia corrugatus, and it is a voracious predator. Parborlasia eats almost anything it can lay its proboscis on, including sponges, sea stars, and scallops. Photos from the seafloor near McMurdo show massive piles of the brown worms in feeding frenzies.

The thing that gets me about Parborlasia is its size. Most nemerteans are small, only 10s of centimeters long, usually 1 cm wide or less, detectable only be a trained eye. Parborlasia can grow up to 2 m - a clear example of polar gigantism. But like all nemerteans, it has no circulatory or respiratory system, relying on diffusion across its skin to supply its cells with oxygen. Usually only small animals can get away with diffusion, because if they're too big, there's not enough surface area of skin to supply the whole volume of the body with fresh oxygen. Some of us in the training program have measured the metabolic rate of Parborlasia, and so far, it looks like the metabolic rate is exceptionally low. With a low metabolic rate, the worm is less likely to run out of oxygen. What a fascinating creature!