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!


Seen around the station: part 2


In mid-summer every year, a supply ship comes to McMurdo Station. Even at the warmest
part of the year, the sea ice is too heavy for the ship to get through by itself, so it has to be
preceded by an icebreaker. This icebreaker, a Coast Guard vessel called Polar Star, cut a
channel through the sea ice in McMurdo Sound so the supply ship could get through.

The supply ship, Ocean Giant, coming into port at McMurdo

The research ship Nathaniel B. Palmer also stopped in at McMurdo
Station while the ice channel was open

Antarctica is international territory, and under the Antarctic Treaty of 1959, all commercial
activity and military exercises are prohibited. This cartoon makes light of the potential for
commercialization after the treaty expires.


Seen in the Crary lab at McMurdo Station

Wednesday, January 24, 2018

Arrival Heights

Snow-dusted Antarctic terrain
"It looks like the moon...or something."

Harriet sat next to me on the bench in the van, and I could hear her smooth, deep voice over my shoulder. We were squished in a row of four on a seat probably meant for three, and we were gazing past one another out the windows. The extraterrestrial terrain was dusted with snow as our van rattled up the hill.

Sensor antennae at Arrival Heights
We drove up the slope and stepped out at a place called Arrival Heights, on the ridge standing high above McMurdo Station. The wind whipped around us, swirling snow and obscuring the view as we stepped out of the vans. When I peaked out from my hood, I could see we were surrounded by a field of antennas, and a large white ball stood atop a compact building on the flat top of the hill.

The door to the building opened, and we squished inside. The entryway was obviously not meant for so many people. Removing our parkas, we emerged into a larger room with a computers and control boxes and monitors secured in a series of metal racks. Posters on the walls explained the basic principles of atmospheric science.

The sensor control area in the Arrival Heights lab
Arrival Heights is a special area set aside for atmospheric research in Antarctica. The sensors monitor very low frequency waves to "listen" to the atmosphere. There are several scientists using the facility, each with their own sensors set up to collect data, and one research technician who stays in Antarctica all year to maintain them. The technician showed us the computer monitors where results were displayed. He pointed out to us the openings in the ceiling where the smaller sensors were mounted. He played for us a sound recording of what the sensors "heard." He called it a "whistler," but it really sounded like laser guns firing in Star Wars. It was the sound of lightning striking Earth in the northern hemisphere and propagating a wave through the planet's magnetic field. Very, very cool.
The floor-to-ceiling aurora sensor

In one small room, there was a sensor that reached floor to ceiling. It had a hefty steel base and stretched up through a hole in the ceiling. The technician explained it was for monitoring the aurora australis and pointed out the optic sensors and the filter on top. We can't see the aurora in the summer months because the sun is always up, but the sensor can see them. The technician pulled out photos that the sensor had taken in the past few days, showing fluorescent plasma in the upper atmosphere - the southern lights.

Antarctic research encompasses all disciplines, from biology to geology to physics. I was grateful to experience another aspect of Antarctic science at Arrival Heights.

Monday, January 22, 2018

Discovery Hut

Discovery Hut
McMurdo Sound was one of the first areas of Antarctica reached by European explorers, so it is rich in history from the "heroic age." One of the most notorious Antarctic explorers, Robert Scott, camped in McMurdo Sound and set out from here on multiple expeditions, including his infamous, ill-fated quest for the South Pole. While at McMurdo Station, my fellow trainees and I have had the privilege of touring Scott's historic Discovery Hut, located just down the road from the station. The hut is a specially-managed historic structure, and access is allowed by permission only. It was a rare opportunity for us to experience the early history of Antarctic research and the poignant realities of life on the southern continent before well-established infrastructure.

That, my friends, is a century-old seal carcass
Discovery Hut was never meant to be inhabited. Scott and his men used a design common in the Australian outback - obviously not a fitting choice for Antarctica, designed to shed, instead of retain, heat. They intended the hut to merely serve as a storage unit, a place to leave extra supplies when they headed out on treks over land. During harsh winters on subsequent expeditions, the men did end up living in the hut, and their diaries reveal how atrociously cold it was inside. They lived in near-hypothermic, near-starvation conditions for months on end.

Old supply boxes inside Discovery Hut
As I stood outside, waiting to enter the hut, I couldn't help but notice a long black object to the right of the door. I stepped closer to examine it and discerned a head and shriveled flippers. It was a seal carcass, over 100 years old, left behind by Scott's men and too cold to rot.

The primitive "kitchen" inside Discovery Hut
When I stepped inside, the first thing I noticed was the darkness. There are very few windows inside the hut and no electric lighting. It took about 30 seconds for my eyes to adjust. The second thing I noticed was the smell, which was something like stale dust mixed with old manure. We were warned there was horse manure inside, but I never saw any. Instead, I focused on a pile of wooden boxes, all labeled for the expedition, some still carrying canned foods. Our course instructor explained that Scott's expedition relied on hunted seals and canned meats they had brought with them for food, and they suffered from terrible scurvy.

We worked our way around the central axis of the hut to an area partitioned with hanging fabrics. This area was the kitchen, or the closest equivalent, and the blankets were meant to retain heat from the stove. An old metallic bowl held charred bits of something that reminded me of burnt bacon - leftover pieces of seal meat, abandoned where they lay for over 100 years. Our instructor pointed out the crude wooden planks where two of Scott's men had lain and been tended to just prior to their deaths. He showed us the short brick chimney where the scientist, Wilson, had done his first studies on magnetism in an attempt to locate the magnetic south pole.

The latter point is actually a defining characteristic of Scott's expeditions: he brought a scientist with him. Roald Amundsen, the other famous Antarctic explorer, was much more efficient and successful (Amundsen beat Scott to the South Pole) but did no science along the way. Scott's expeditions were the first real foray into Antarctic research, but each expedition was more ill-fated than the last, culminating in the deaths of him and his entire team. After seeing Discovery Hut, I must admit: I do not wonder why Scott died. Amundsen showed up with professional skiers and sled dogs and fur coats; Scott's men had no such training and pulled their gear on sleds themselves. I respect their raw grit but marvel that Scott ever convinced men to follow him, much less to return with him, to the Antarctic.

The contrast is best summarized by a famous quote attributed to Raymond Priestley: "For scientific discovery, give me Scott; for speed and efficiency of travel, give me Amundsen."

It was a rare privilege to see inside Discovery Hut, and I was grateful for the opportunity. The historic hut provides a poignant view of the continent's history and valuable lessons for modern research.

Saturday, January 20, 2018

Swimming butterflies

The common Antarctic pteropod, Limacina
antarctica
, photographed under a dissecting
microscope by Brandon Hassett.
The jar was full of cold, clear Antarctic water. Inside, I could see three or four black specks that seemed to be bobbing up and down in the water. The jar had been sitting still for a while, so I didn't expect the water to be moving that much. Leaning closer, I noticed the black specks were surrounded by clear, spiral-shaped shells. Two lobes of tissue emerged from the shell like little wings. All of a sudden, the animals came into focus. My brain found the word for them: pteropods.

Pteropods are commonly called "sea butterflies" because of those two wing-like lobes. They're related to snails and sea slugs, but they spend their entire life-cycle up in the water column, not on the seafloor. Pteropods use their lobes, which are modified extensions of the foot, to swim up and down in the water column. The lobes ripple and beat like butterfly wings, carrying the animal up to the surface of the water. At the surface, the pteropod constructs a mucus net, which it spreads over itself like a parachute to catch particles to eat as it sinks back down. They're beautiful and fascinating creatures.

Swimming pteropods in one of the respiration
experiments
My small group has gotten interested in pteropod swimming activity and started pursuing an experiment with the most common Antarctic pteropod, Limacina antarctica. We're trying to figure out how energetically expensive it is for the animals to swim in their characteristic up-and-down pattern. How much food does a pteropod have to catch in its mucus net to make swimming back upward worth it? To answer this question, we're measuring the respiration rates of swimming pteropods and resting pteropods at different water temperatures. We're putting pteropods in closed flasks where they can swim, then measuring the concentration of oxygen dissolved in the water over time. As a comparison, we've put resting pteropods in closed flasks that are not large enough to swim in, and we'll measure their oxygen consumption too.

I haven't done any experiments with respiration or animal physiology since I was an undergraduate, so it's fun for me to learn new techniques. The pteropods are also goregous animals that are relatively easy to work with. It will be fun to see what the data show!

Thursday, January 18, 2018

Play

"Play is the highest form of research." - Albert Einstein

I was the last one in the row walking single-file out of the aquarium. I turned around to scan over the room one more time, then stepped into the hallway as the aquarium door swung shut behind me.

Scallops in the channel. The one up on the wall has attached
itself with byssal threads.
Mark shrugged. "Well, we'll see what happens," he said. Everyone smiled. We were excited to see what our experiment would yield.

A key part of the Antarctic training program is not just learning how to collect samples in Antarctica, but how to best make use of the lab facilities at McMurdo. As in all things, we're learning by experience, by setting up small group projects to investigate organisms we're interested in. My group noticed that the scallops in McMurdo Sound, Adamussium colbecki, form byssal threads. It's pretty common for bivalves to attach themselves to a substratum using biogenic threads, but we started wondering what factors would prompt a scallop to make the byssus (or not).

To find out, we set up an experiment in the Crary Lab at McMurdo Station. We used leftover tanks to partition a channel in the seawater flow-through facility. We split our scallops between the channel (with high flow) and another segregated area (with no flow), expecting that the scallops in the flow would make byssal threads to withstand the sheer of the water moving past them.

Byssal threads on a scallop. 
It was a bit difficult to get the flow in the channel up to a level that would really affect the scallops. We could only get it to about 4 cm/s, which is freaking slow in biological terms. After leaving the scallops overnight, we returned to find that only 1 out of 5 individuals had made byssal threads in the flow treatment, but 1 out of 5 individuals had made byssal threads in the no-flow treatment. The pattern was clear: flow does not prompt scallops to make byssal threads.

We'll keep playing around with the scallops over the next few weeks. Personally, I'd like to measure the tensile strength of the threads they make, because similar byssal threads made by mussels are notoriously strong. I'm glad for the opportunity to study Antarctic species and learn by experience how research is done down here!

Wednesday, January 17, 2018

Seen around the station

The rows in the storage area are named after types of facial hair.

The community message board at McMurdo shows just how bored people get.

Antarctic pick-up truck

This is where you plug in kiwis.
Actually, it's a courtesy car engine-warming station for New Zealanders
who stop over. The New Zealand base is just 3 km away.

This troll guards a pedestrian bridge over some fuel lines in the
middle of the station.

Tuesday, January 16, 2018

Long live polar invertebrates

Friends, I love polar regions. I love the cold, dry air. I love the wind. I love the constant daylight and the constant darkness and the challenges of working at the end of the earth.

And I love the biodiversity.

Polar regions are renowned for the breadth of animals they possess. I'm not talking about polar bears and penguins (you know me better than that). I'm talking about the animals underwater, on the bottom of the sea. Polar benthic invertebrates have extremely high diversity - more than you would ever expect. You see, oceans in both the Arctic and Antarctic have low temperatures and low productivity, characteristics suggesting that very little would grow there. But exactly the opposite is true. The seafloor in both polar regions is covered by an incredibly diverse array of fauna. In fact, the colder areas are the ones with the highest diversity, to the point that a single trawl could supply an invertebrate zoology class.

Animals collected by divers in McMurdo Sound
How in the world could such an array of invertebrates live in such cold temperatures and with such little food? It's actually an important research question that I intend to pursue. I got one hint a few years ago, and you might remember it if you were following this blog during my Svalbard recruitment experiment. I put out plastic panels in Arctic fjords to see what would grow, and the site with the highest biodiversity of adults had the lowest number of recruits. I started thinking that the invertebrates in the cold fjords might have long life-spans - sure, they grow slowly, but if they all live a long time, then there will always be a lot of them around.

I'm anxious to test out my ideas in the Antarctic, because the biodiversity in McMurdo Sound is absolutely incredible. Some divers from the station collected animals for us, which are currently living in seawater tanks in the Station's main lab. There are sponges and soft corals and sea stars and scallops and slugs and anemones.

Because it's so cold and dark under the ice, the conditions are similar to the deep sea, and there are actually many taxa living at shallow depths in Antarctica that are usually only found in the deep sea. For example, the soft coral you see in the photo above is called Gersemia antarctica. It's closely related to another species, Gersemia fruticosa, that lives on the continental slope of the north Atlantic, far offshore and at much greater depth.

Sea stars from McMurdo Sound
Much of the seafloor in McMurdo Sound is covered by large sponges, and you'll see a couple examples in the photo above. The sponges are called "foundation species" because they form the base of a flourishing ecosystem. Their large physical structure provides shelter for other animals, and they also serve as an important food source, especially for sea stars. There has been several studies on McMurdo sponges since the 1970s, but I can't help but imagine what experiments I would like to do in the future. The high biodiversity of benthic invertebrates in polar regions makes for gorgeous and fascinating communities. Long live polar invertebrates!

Saturday, January 13, 2018

Ob Hill

There's a large hill right next to McMurdo Station called Observation Hill (though most people just say "Ob Hill"). I had the chance to hike it today during a break from the lab. The climb is actually pretty steep, but the views on top are worth it! Check out my photos below.

McMurdo Station, seen from Ob Hill
The icebreaker Polar Star arrived in McMurdo Sound yesterday
and is working to break a channel in the ice so supply ships can
get through and re-stock the station.
Mt. Erebus

Those green buildings below are Scott Base, New Zealand's
Antarctic research station, located just 3 km from McMurdo
This cross atop Ob Hill honors Robert Falcon Scott and his team,
all of whom perished after being the second team ever to reach the
South Pole (the first was lead by Roald Amundsen)

Holes: part 2

"After a while he thought he could make out the shape of the mountains through the haze. At first he wasn't sure if this was another kind of mirage, but the farther he walked, the clearer they came into view...He kept walking toward [the mountain], although he didn't know why. He knew he'd have to turn around before he got there. But every time he looked at it, it seemed to encourage him."
- Louis Sachar in Holes

Mt. Erebus
Friends, I am opening this post with a photo of Mt. Erebus, the world's southernmost active volcano. Erebus dominated my skyline yesterday, slowly releasing plumes of water vapor from its summit. The mountain breathed along with me, taking deep, clear breaths of the Antarctic air. Its majestic peak was unmistakable against the clear blue sky. Yesterday was an awesome day. 

A Pisten Bully
It started with a ride in a Pisten Bully, which is a rough-and-tumble vehicle designed for Antarctic travel. By now, I'm getting used to the loud engines and rough rides - that's just how vehicles are down here. Thankfully, we only took the Bully to the snowmobile staging area, which sits on the ice shelf just outside of town. We technically could have taken it all the way to our site, but Pisten Bullys have exactly two speeds - dead slow and stop. It was much to our advantage to continue the journey on snowmobiles. We unloaded all of our gear and secured it to a series of sleds, then daisy-chained the sleds to the snowmobiles and piled ourselves on top. It felt a bit like riding a horse, to be honest. I sat astride a dense red survival bag on top of one of the sleds and used my inner thighs and my abs to keep balance on the curves. Not something I ever expected find myself doing, but it was fun. 

Adelie penguins!
As we arrived at our study site for the day (a hole drilled in the ice for us by McMurdo staff), the last remaining clouds cleared, and we could see across the Sound in all directions. Mt. Erebus stretched over the skyline, and the sun shone down on us. It was marvelous. 

Luana and I had fun lowering the zooplankton net into the
hole. Yes, that is a bamboo flag pole and a spool of line serving
as our winch.
Just when I thought the working conditions couldn't get any better, somebody in the group gasped. "Penguins!" they called, and pointed to the north. Just about 100 feet away, a group of Adelie penguins emerged from another sea ice hole (the one we couldn't use because of the seals). The Adelies were curious and waddled straight towards our group. One of them kept stopping to sniff the air and look at us. He must have decided we were safe, because eventually all 5 of the penguins walked straight past us - within 10 feet of the closest person. I was impressed at how quickly they moved and how fluidly they switched between walking and sliding on their bellies. If a penguin tripped on a chunk of ice, it would just keep moving its feet at the same rate to push itself along, acting all the while like nothing happened. That said, the little birds tripped pretty often and actually reminded me of a group of toddlers. They waddled past us and were gone just as quickly as they came. 

We spent the rest of the afternoon collecting samples of water and plankton from the ice hole. The water will be used to estimate the densities of bacteria and phytoplankton in the water, and the plankton net samples will be used to see what species of phytoplankton and zooplankton are there. In case you don't know, "plankton" refers to all organisms too small to swim against the current. Phytoplankton are microscopic algae, and zooplankton are tiny animals, including copepods and larvae (my favorite). It was an amazing day on the ice, and I can't wait to see what we caught!