2 November, 1998
November 2, 1998
Yesterday was a superb day! It was great weather, not too cold (about 2 degrees F) with no wind and it was full of "firsts" for me, including one dream come true:
my first ride in a spryte (the vehicle Fox Mulder drove across the snow in the X-files movie), my first ride on a snowmobile, my first ice-fishing experience, my first close looks of Weddell Seals, my first visit to a historical hut of an Antarctic explorer (Ernest Shackleton), and, best-of-all, my first visit to an Adelie Penguin nesting colony.
FISHING AT CAPE EVANS
At about 11:00 I put on my ECW (extreme cold-weather)gear and met with my PI (Principal Investigator) Dr David Smith and my co-TEA-teacher (Skip Zwanzig) to go out to Cape Evans where the team has a fishing hut on the ice. This site was selected by the graduate student Sierra Guwynn who figured it should be perfect shallow-water habitat for the fish we are studying (Trematomus bernacchii). She was right. Fishing here is like fishing in a fish bowl. We caught about 30 fish in a short time. I caught two. Sierra and Dr David Petzel (the other PI) were already at the hut which is heated by a stove to keep us warm and to keep the meter-wide ice hole from freezing in our absence. Normally we would fish from this hole, but a dive-team was sharing the hut with us today so we had to fish from smaller holes that we drilled with a huge hand-held drill. This gadget drills holes about 10 inches in diameter and by adding various extensions to its drill-bit we can drill through several meters of ice. In this case we had to drill through the 8 feet of ice. We fished with hand-lines baited with a rubber worm. Sierra used a kids' Snoopy fishing pole about 1 foot long. Since the air was so cold, when we caught a fish we had to very quickly and carefully remove the fish from the hook and drop it in a bucket of seawater so it didn't freeze. Any crystal of ice that penetrates the skin can serve as a nucleus for more ice crystals to grow from and this will quickly kill the fish. Even though they do have antifreeze and high salt concentrations which prevent them from freezing in their normal habitat, exposing them to ice and cold air is not a situation they are adapted for. The fish were placed in coolers full of sea water and aerated with battery-powered air bubblers for the one and a half hour spryte-ride back to the aquarium at McMurdo's Crary Lab where they will be used for experiments to study what controls their salt levels. Their salt concentration, twice as salty as normal marine fishes, is one of the reasons why they don't freeze in their -2 degree Celsius environment. (The other reason is the antifreeze glycoproteins they have in their blood. Glycoprotein is a aprotein with sugar attached to it. A different team of researchers is studying the antifreeze.) Salt gets in the way of ice crystal formation, lowering the freezing point of the water (calligative property). This is the same reason road salt is added to highways in winter snow storms.
Trematomus bernacchii is a very odd-looking fish. It is only about 8 inches long with a big head, big eyes, big mouth (to eat anything it can get into its mouth), relatively small tail, huge fan-shaped pectoral fins (which power most of its motion) and a beautiful pattern of brown and gray mottling on its back. This mottling pattern, especially its color and shade, can vary from fish to fish. It spends most of its time just sitting on the bottom waiting for food.
The water at this fishing hut was not very deep, only about 60 feet, and we could easily see the bottom through the big fishing hole. I was amazed at how much life I could see down there in the freezing cold water --starfish, big, foot-long nemertean worms, swarms of crustacea called amphipods. The divers were going under to photograph and collect algae samples. Their normal work is to study foraminiferans over at New Harbor. These foraminiferans are large (1 mm)one-celled protozoa like amebas that secrete a glue and use it to construct a protective shell out of sand grains around them. Other kinds of foraminiferans secrete calcium carbonate shells around them. (The chalk your teacher uses on the board is mined from deposits of similar foraminiferans that accumulated over millions of years as their shells settled to the bottom of the ocean after they died.) You must be tough to be diver in Antarctica. The water is so cold that even with the best drysuits for keeping all water away from the body you can get too cold to function in much less than an hour. That combined with the pressure of all the water above them (they dive to 90 feet at New Harbor) they can only stay under for about 30 minutes at a time.
Cape Evans is also the site of Scott's hut. Scott's team of explorers was the second group of people to reach the South Pole in January 1912. They were beaten to the Pole by a Norwegian team led by Amundsen who got there just a month before Scott. On the way back to their hut from the Pole, Scott and his team died. You can read about Scott's journey in excerpts from his journal in "Scott's Last Journney" and by one of his fellow explorers "The Worst Journey in the World" by Cherry Apgard-Gerard. While we were fishing, two busloads of people (in ice-buses wth huge tires)came from McMurdo base to look at Scott's hut and check out what we were doing.
THE BARNE GLACIER AND WEDDELL SEALS
When we were done fishing Sierra and Dr Petzel drove the spryte back to McMurdo to put the fishes in some aquaria and the rest of us went by snowmobile to Cape Royds about 1/2 hour away. I rode in back since I haven't been to snow-mobile school yet. The scenery along the way was unbelievable. For about 1/3 of the way we passed by the end of the massive Barne Glacier which comes off the slopes of Mt. Erebus. Its huge blue ice-cliffs towered above some Weddell Seals who were lounging around in the nice "warm" sun. We stopped our snowmobiles to get out and shoot pictures of them and their doggy-faces. They just looked up at us with their puppy eyes, seeming to be totally unconcerned with our presence despite the fact that their ancestors were probably eaten by Scott and his crew at Cape Evans back in the early 1900's. These huge blubbery critters with their grub-like bodies and maggot-like locomotion on ice are renowned for their gracefulness in water. We saw one swim under the fishing hole in our hut probably looking for the same thing we were (Trematomus bernacchii). It was truly graceful. They are superb swimmers; they can dive as deep as 600 meters (without suffering from compression sickness) and can stay underwater for 70 minutes! Only sperm whales and elephant seals can dive deeper than them. They know where all the ice holes are and have a great ability to find cracks in the ice to surface when they need air. Their front teeth are specially adapted for breaking through the ice that may have formed over an icehole or crack that they frequent. (A skull of a Weddell Seal on display here in the lab shows the result of this wear and tear; the front canines and incisors are all worn down from repeated ice grinding.) One seal even surfaced in a fish hut while Skip and Dr Petzel were there fishing! They can go for 15 or 20 minutes without breathing! How long can you hold your breathe?
How can these huge critters live with such a low supply of oxygen? First of all it has two times more blood per pound than a human does, and that blood has twice as much hemoglobin (the oyxgen-carrying protein in blood) than a similar volume of human blood. SO they can carry at least 4 times as much oxygen. They also store a lot more oxygen in the myoglobin protein found in their muscles than we do. They can also shut-off the circulation of blood to organs that aren't needed as much during a dive, providing more oxygen to the organs that need it. AMAZING!
How can these hunky homeotherms keep a high body temperature in this icy water and freezing air? They have a layer of blubber 5 centimeters thick all over their body. Their limbs are small to prevent heat loss and they have a special circulatory system that uses the warm water going into the flipper from the body to warm-up the cold blood returning back to the body from the flipper. WOWEE-KAZOWEE! That same system of keeping limbs warm is found in the fliper of the next critter.
At Cape Royds we parked the snowmobiles and hiked up over a hill into a basin-shaped area that was full of Adelie Penguins, the southern-most colony of Adelies in the world. It was so amazing to stand there, my excited breathe freezing all over my beard and moustache, and watch the interactions between these cute looking penguins. The air was filled with the nasal braying of the displaying birds and with the scent of bird guano from generations of penguins nesting here. The birds are still arriving from their wintering grounds in the open ocean as it is spring here. Skip said the numbers have doubled since he was here a couple weeks ago. The birds were busy establishing nesting territories, building nests, and displaying to each other. Their territory is basically just as far as they can reach out to peck someone else. Their nests are scrapes in the ground lined with rocks. It was fun to watch one bird waddle about 10 feet, tug a volcanic pebble out of the volcanic ash, waddle back over to its mate who was lying on the nest, and gently drop the pebble in front of her as if it were a precious gift. In other cases I saw penguins trying to sneak by and steal rocks from other penguins' nests. This was quickly followed by a rough-and-tumble chase through the colony colliding with several other penguins along the way. Quite a commotion. All the other penguins were "shouting" at the intruders and reaching out to peck at them from their nests as they ran by. Looking across the colony of a few hundred birds over half of them were lying on their nests as if they had eggs, although no eggs had been laid yet. They were just lying on the pebbles. I also saw several groups with displaying birds. These birds were facing each other, standing up straight, their beaks pointed up, their head feathers and rump-feathers raised in excitement,and their wing-flippers out-stretched and flapping slowly. (For Fun: Why don't you all get up now and act out the Adelie Colony behavior right there in classroom.) I also watched a couple of penguins approaching the colony on the frozen sea ice, waddling, hopping, calling out. It was a long journey to the sea edge for these penguins. As I scanned with binoculars from a rock promontory overlooking the colony and the sea ice, I couldn't even see the ice edge.
Ernest Shackleton was another Antarctic explorer in early 1900's. He wrote a book I read in 7th grade called "Endurance". We went into his old hut here at Cape Royds which is still pretty much just the way he left it. It was amazing to think about the cold conditions that he survived through using just the supplies we saw there in his hut. There were several cots surrounding a stove. There was a teapot and some toaster grills on the stove. The cots had seal-skin sleeping bags on them and seal-skin boots under them. Kerosene lanterns hung on the walls. The shelves were full of canned and dried goods as well as medicines for diarrhea and other ailments. Some shelves had variety of tools, now rusty. There was a miniature lab in one corner for scientific investigations. A picture of the King and Queen of England hung on the wall. Hanging in the eaves of the roof were the sleds they used to drag supplies across the snow and ice. What a contrast between the life we scientists now lead here in Antarctica and the life they led back in Shackleton's day!!
BACK TO MCMURDO
At about 7:30 we had to leave Cape Royds in order to return to McMurdo by the 9:00 time we radioed in for our return time. On the way back the views were absolutely GODgeous. The low evening light gave beautiful shadows and texture to the sastrugi (wind-sculpted ripples in the snow) on one side of our road and illuminated snow-covered Mt Erebus with a gleaming light on the other side of the road. If I had been driving the snowmonbile it would have taken 3 hours to get back as I'd be stopping continuously for photographs. Everything was so sharp and clear illuminated by this rich evening light: the red shelters of the seal researchers' camp next to the gray-black Razorbill Island, the iceberg frozen in the ice, gray clouds partly obscuring the base and flanks of Erebus so its glowing snowy shape had a mysterious look. Behind Erebus was a nice blue sky and a 3/4 full moon. I was entranced by the twinkling lights of individual snow grains reflecting the sunlight as we zoomed by in our snowmobile, only jarred back out of my dreamlike enjoyment of the scenery by a jolting bump in the road that threw my tailbone into the corner of the hard storage box on the back of the snowmobile.
Well it's time for a cup of coffee and the start of a busy day in the lab. I have really been enjoying Antarctica; now its time to get to work.
Have a good day and do something good for someone.
DO YOU YAHOO!?
Get your free @yahoo.com address at http://mail.yahoo.com
Contact the TEA in the field at .
If you cannot connect through your browser, copy the TEA's e-mail address in the "To:" line of your favorite e-mail package.