A history of exploration

For a long time, Antarctica was an unknown continent. In the 1400's and 1500's, Antarctica was just a hypothesis. So, at the time that Leonardo da Vinci and William Shakespeare were alive, nobody had seen Antarctica, but they thought it probably existed. It was referred to as Terra Australis Incognita (unknown southern land). Maps from the time show a rough outline of where they thought Antarctica was.

Photo credit: Wikimedia

People began taking ships further and further south to find this new continent. They encountered islands along the way, which they sometimes thought were attached to that southern continent. (They were wrong!) Some of the maps from that time are very funny!

Compare this map of Antarctica from 1616 (from the Princeton library) to the real one below. They didn't quite get it right!

The first historical record of humans seeing Antarctica in person is from the 1820's. (I say 'historical record' because it's quite possible that Polynesians from the South Pacific had discovered Antarctica well before the rest of the world, but it's hard to find written record of it.) These first sightings were from ships traveling to the coast of Antarctica. Humans didn't start walking around on land until the early 1900's. These explorers were like the astronauts of their time! They were traveling into a completely unknown land, far from the rest of civilization, and the only resources they had in these extreme conditions were what they packed with them. The idea of spending a year in Antarctica was similar to the way we think about spending a year on the International Space Station today. They faced dangerous conditions, and if they returned from their expedition alive, they were famous!

Much of the early human activity on the Antarctic Peninsula wasn't for science or prestige, though. Some of the first human inhabitants on the islands near Antarctica were sealers and whalers. (Those are people who hunt seals and whales for their fur, meat, and blubber.) A lot of whales and seals migrate to the ocean around Antarctica during the summer, because there are a lot of krill and phytoplankton to eat. That meant the hunters could make a lot of profit! King George Island, where we are working, was the base for a lot of seal hunting in the early 1800's and by the end of that century, the fur seals were almost entirely gone.  

Fur seals have returned to the region, after being over-hunted in the 1800's.

Then the whalers moved in during the early 1900's. Whaling was so busy that almost all of the world's whale species were hunted close to extinction! Less profits meant that a lot of the whalers left, and then of course it is now illegal to hunt whales or seals in Antarctica for profit. 

The whalers and sealers were the only inhabitants of King George Island until the 1940's when scientists arrived. Many of the places that were once whaling camps are now scientific research bases used by many different countries. In fact, whale bones are still lying around King George Island near the bases.

The spine and rib cage from a whale near Arktowski Station on King George Island.

Ecological succession even happens on skeletons! Moss growing and soil developing in a whale vertebra at Admiralty Bay on King George Island.

Today, only research bases remain on King George Island, and there are many from nations all over the world. It is only a place of scientific exploration and cooperation, not hunting! The bones remain as a reminder of the damage humans have caused in the past.

Want to know more about the history of King George Island, specifically? This article gives a nice summary!

Antarctic gardening

We have been busy working in the field to set up our main experiment. This is an important way that we can study the plant-soil feedbacks during succession. How do you know for sure that adding a plant changes the soil? You add a plant to bare soil, and see how the soil changes! So, we are starting a "transplant" experiment. 

We are taking grass, moss, and algae from the surrounding area and planting them into bare soil in an early succession zone. (So, we are "transplanting" the plants from one area to another.) We sampled the bare soil before adding plants, so that we can understand the early succession soil before plants colonize.

Here I am, sampling the bare soil in one of our soon-to-be transplant plots.

We will measure the bacteria, fungi, and invertebrates in the bare soil. We will also measure the amount of nutrients and other chemical properties that are important for sustaining life. That will give us a picture of the soil before plants arrive.

Then, we did a little gardening! A couple days ago, we moved tufts of the Antarctic hairgrass into our bare soils. 

Dr. Hannah is happy to plant her grass.

Today we moved two different species of moss. Not all moss are the same! Some mosses are pleurocarps, like Sanionia on the left side of the photo. They spread out on the surface of the soil, growing overtop of what's below them. They make a mat that you can peel up from the ground, almost like a carpet. (They can also regenerate from pieces of the mat that have blown in the wind, and survive on top of rocks, making them good pioneers in early succession!) Other species, like Polytrichastrum on the right side of the photo, are acrocarps. They grow into the soil. Their rhizoids (the root-like part of the plant) intertwine into the soil like turf. Those we have to move in tufts like grass.

Sanionia (the pleurocarp) is being laid down on the left. Grass is in the middle, and Polytrichastrum (the acrocarp) is on the right.

We have one more plant left to move, which is the algae. We will hopefully be able to finish that tomorrow, and our experiment will be set up!

As the plants grow, they will begin changing the soil. They will perhaps add nutrients, create a habitat for more soil organisms, and change the temperature and moisture of the soil. We will revisit these transplants for three years to measure how the plants change the soil as they grow. By making the same measurements as we make on the bare soil at the start of the experiment, we will see how the plants change the soil chemistry and biological community.

It feels good to have our main experiment almost completely set up!

Birds on the Antarctic Peninsula

Because I study soil, I talk a lot about the microscopic organisms that live in soil. But there are, of course, other, big animals that spend part of their year in Antarctica. Some people find these animals interesting, so I'll tell you about some of them. (But how could they be MORE interesting than springtails and midges?!?!) 

The coolest diversity of animals that live on the Antarctic Peninsula are the birds, so I'll start by talking about those. There are actually quite a lot of birds that spend their summers in Antarctica! Here are a few that I think are the most interesting.

One of my favorite species is the giant petrel. I like them because they are so big! Their wing span is 6-7 ft. Their length wingtip-to-wingtip is bigger than many humans are tall! They are seabirds who eat fish, squid, penguin chicks or other birds... and generally anything they can fish out of the ocean.

My pictures of adult giant petrels aren't very good, but you can see lots of other pictures at eBird.

A baby giant petrel, in a much better photo taken by Terri Nelson.

Everyone's least favorite bird is the skua. Skuas are very aggressive. They are scavengers who eat whatever they can find, sometimes by stealing that food from others. They will dive at other birds carrying food to startle them into dropping it. They'll even do it to humans if you're outside carrying a sandwich! They are also very curious and will steal shiny objects, so they have been known to pull off metal tags, steal flagging that marks your research sites, and even steal your computer cables! They can be very pesky when you're trying to do science.

A skua stalking around our field camp, looking for food to steal. You can see more pictures at eBird.

Skuas are much less mean when they are this size!

Skuas are also very good parents. They will attack anyone who tries to come near their nests! They nest on the ground and the eggs and chicks are very well camouflaged, so you might not even know you're near one. But you'll know when a skua dives at your head with its very sharp beak! They don't want anybody getting near their babies.

Another interesting bird is the snowy sheathbill. They are kind of ugly, because they don't have feathers on their face. Like vultures, they eat carrion (dead animals), feces, and other things they can scavenge. That means they have to put their faces in some pretty gross places! You probably haven't heard of a sheathbill before, because there are only two species of them, and they both live around Antarctica or the islands just to the north.

Snowy sheathbills photographed by Terri Nelson. You can see her scientific illustrations of sheathbills and other birds here. You can also see other pictures of them at eBird.

Of course the most famous Antarctic birds are penguins. Let's not forget that these are birds, just birds that can't fly! Their body shape makes them good at swimming, but very goofy on land. There are three species that live on the Peninsula where we work: chinstrap, gentoo, and Adélie penguins. Penguins are the most stinky of the Antarctic birds. They eat krill, which makes their poop smell very "fishy". They poop all around their nests, so rookeries are covered in poop (called guano), and boy does it smell bad!

Chinstrap penguins have that name for an obvious reason!

Gentoo penguins have the white splotch on their head.

Adélie penguins have the white ring around their eye.

So there is your introduction to a few of the birds that live on the Antarctic Peninsula. They live alongside other marine animals like seals and whales, but we will talk about those another time.

Invasive species in Antarctica

Antarctica is a harsh continent, so only specialized organisms survive here. These are species that evolved to withstand the freezing temperatures, periods of darkness, and lack of water (and in some places, lack of food!).

Because of the warming climate, though, organisms from other continents can survive in Antarctica now. If those foreign species arrive in Antarctica, they might not die in the harsh habitat like they would have a few decades ago. The Antarctic Peninsula has a growing problem with invasive species. 

One invasive species in Antarctica is a grass. I've told you about the one native species of grass, the Antarctic hairgrass (Deschampsia antarctica). In Antarctica, it can only survive on the northern end of the Antarctic Peninsula. There is also an invasive grass that has been able to move into some areas. That grass is Poa annua, also called bluegrass or meadow grass. It is a species of grass that grows in a lot of places over Europe, Asia, and North and South America, but was not able to survive in Antarctica. But now it can, and it has established itself on King George Island where we are working. This is a problem, because it is a grass that is very good at outcompeting other grasses, so can take over an ecosystem. That is especially possible if the climate continues warming in Antarctica! How did it get there? People visiting Antarctica, carrying seeds in their boots or gear without realizing it.

Poa annua reported by Znoj et al. in this paper.

There is also an invasive species of midge that has moved in on the Peninsula. There is a native midge I've already told you about (Belgica antarctica), but there are also distant relatives of that midge that now live in Antarctica (Eretmoptera murphyi). How did they get here? They were brought in by accident in some potted plants that were being moved to Antarctica from other islands north of Antarctica for a scientific experiment. (That is why there are such careful restrictions about transporting soil and plants now!) This new midge is unlike any other organism that lives on Antarctica: it eats dead plant material. The islands along the Antarctic Peninsula are covered in a lot of dead plant material from old moss and grass. (Because nobody lives forever, but its decomposition is naturally very slow so it builds up over the years.) So, the invasive midges have a lot of food, but no predators living there, so they can grow and reproduce a lot! They can eat a lot of the dead plants, recycling the nutrients and creating soil much faster than would happen naturally. It is a level of consumption that does not naturally exist in this area! They create so much change that they can be considered an "ecosystem engineer". 

You can read an article about this pesky alien midge here.

The midge isn't the only invasive insect in Antarctica. On King George Island, where our work is based, there is another invasive insect called Trichocera maculipennis. This is a crane fly that is native to the northern hemisphere, mostly in Europe, so it moved a long way! They survive around sewage systems of the research bases on the island. This species of fly can actually fly! They can survive out in the natural environment away from the sewage, which is how they can move from station to station. This species exists here at Escudero station, and one has already flown into one of our samples!

You can read about this species and other invasive species with the British Antarctic Survey.

These species were all accidentally introduced by people, because their larvae and seeds are so small that people didn't notice them on the products they were bringing into Antarctica. We are much more aware of it now, and we are now required to sterilize our boots in between each place we visit in Antarctica so that we do not keep moving them into new places. We have to avoid future damage from bringing in new species that might tip the natural balance in Antarctica!

Collecting data

To collect our soil and plant samples, we use a corer. That's a piece of metal pipe that is in Hannah's hand in the photo below. That cuts out a piece of the plant, which we put in a small envelope. (Those are in the ziplock bags next to Hannah). 

Then we scoop the soil from underneath it into a plastic bag. The plants and soil are taken back to the lab for analysis.

We will do most of our measurements on the samples back in the U.S. We have to spend our time in Antarctica collecting the samples and setting up experiments. We just don't have time while we're here to collect all the data on the samples! We will ship the soil home frozen at -20°C. Those temperatures would kill most of the microbes and invertebrates, though! We extract the organisms from the soil here in Antarctica before we freeze them.

In my lab at Arizona State University, I have special equipment to look at the invertebrates. But equipment is heavy and takes up a lot of space, and we can't bring it all with us. So, in Antarctica, we have to get creative!  

This is how we extract arthropods like mites and collembola. We use heat created by light bulbs.

We use aluminum cans because they are smooth and shiny, which reflects the light from the bulb to keep it bright and warm inside the can.

These arthropods like to be cool and moist. If the soil gets too warm or dry, they will crawl deeper into the soil where it is cooler. We use that behavior to get them out of the soil. Each of these cans has a soil sample inside of it. We then put a string of outdoor Christmas lights over the top. The heat from the light bulb warms up the soil. The arthropods try to move deeper in the soil... except there's no more soil. They fall through the funnel into our little bottle. Now we've trapped them out of the soil and can look at them under a microscope!

Each can has a soil sample wrapped up in a little piece of gauze. The heat from the lightbulb is what makes them want to move down into our funnel.

Smaller invertebrates like nematodes and tardigrades don't respond to heat. These tiny invertebrates live in the water in the soil. To get them out of the soil, we use water and gravity.  

Each of these funnels contains a small soil sample wrapped in a tissue. We fill the funnel with water, and the nematodes swim away from the soil to float in the water. But gravity wins! They sink down to the bottom stem of the funnel, and we will capture that water in a bottle.

At ASU, I have sturdy stands that hold our funnels. We needed to pack light, so I made stands here out of cardboard boxes. It is very fancy, don't you think? The samples sit in the funnels for 5 days. These small invertebrates do not move fast, so it takes time! We put our first batch of samples onto the funnels on Wednesday, which means in a few days, I should have some invertebrates to show you!

Field day

The Collins Glacier here on King George Island has been shrinking. The edge of the glacier has receded back further than it was even just a few years ago. That has exposed soil that is now undergoing succession, which is the focus of our research this year.

One of the ways we are studying succession is by looking at the plants and soil that have been exposed for different lengths of time. Yesterday, we collected samples from the early succession zone that has recently been uncovered by the glacier. This area is still fairly close to the glacier, like you can see in this photo:

This soil has been exposed for only a few years. There are moss and lichens growing on it, but only certain species that are good at being "pioneers". They tend to like wet areas, because the melting glacier provides a lot of it. But they have to be able to gather nutrients in creative ways, because there is not a lot in the soil yet. Those are species like moss in the genus Sanionia, and cyanobacteria who are able to fix nitrogen from the atmosphere.

This moss is in the genus Sanionia. It likes living in wet places, like this channel where melt water flows down from the glacier.

We will also take samples further from the glacier, all the way out into the areas that have been exposed for a long time. These sites have had enough time to reach a "climax community", which is the mature, fully-developed plant community.  That would be a place like I showed you a couple days ago from our scouting trip:

A climax community on King George Island has many species of moss, not just the hardy pioneer species, as well as the grass. The Antarctic hairgrass requires a lot of nitrogen to grow, but can't fix it from the atmosphere like a cyanobacteria. They can only arrive later in succession when the cyanobacteria have done the work for them!

So we are taking samples from across these successional zones: some from early succession, some from a transitional "mid-succession" zone with a few more moss species and grass starting to move in, and then from the "climax community". We use the samples we take to learn about the soil conditions and the community of microorganisms that live at those successional zones. We know that the plants change like I showed you in the photos, but how do the soil invertebrates change as the ecosystem ages? How does that relate to the chemistry of the soil? These are the questions we will be able to answer with our samples.

Tour of Escudero

When we woke up today, we found that the weather is very rainy and foggy. There will be no field work today! It is not safe to leave the base when visibility is low. This was our view out the window during breakfast. There's an ocean out there just beyond the blue building, but you can't see it!

Since we can't go anywhere, I'll show you around the research station a little bit. Most of our time is spent in the main building. (That's the building with the flags in front from yesterday's post.) When we come in from outside, we have to take off our big coats and boots so that we don't track dirt and snow all over the building. We put our boots on the shelf and put on our indoor shoes (kind of like Mr. Rogers). The door to the left in the photo goes to the lounge area with couches and a TV. The kitchen is at the back of that room where we eat our meals.

We spend most of our day in the lab, getting ready for our field work and preparing for our samples. It is a long room that is shared by many scientists working on different projects.

There is a dormitory where we sleep. We have bunk-beds and a couple pieces of furniture to put away our clothes. Here is the room that Dr. Hannah and I share. It is small, but we don't spend much time there, because we are busy working!

There are two bathrooms in the dormitory, for about 20 people to share. There can be a line to use the bathroom! (Often I'll just walk over to the lab to use the bathroom there.) We have to be very careful about conserving water in Antarctica, because we have to clean the water at the station and not allow any to be released on land. The shower has a button you push to release the water, but it only runs for about 15-20 seconds per push. That keeps us from letting the water run too long. You only push the button when you need to rinse.

So now you've seen a bit about where we live and work at the station. Tomorrow we will hopefully have better weather so that we can start our experiments!