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CREIGHTON RESEARCHERS RETURN FROM ANTARCTIC EXPEDITION
For Immediate Release
OMAHA, Neb. -- David Petzel, Ph.D., got some recommendations on good fishing spots during a recent trip, so he and his companions got ready to go. After learning how to drive a bus equipped with tank-like tracks, drive and repair a snowmobile, get in and out of a helicopter, drill a hole through eight feet of ice and use a radio, they got their gear together: a portable fishing hut heated with diesel fuel, the bus to tow it with, the drilling rig to smash a hole through the ice, and the motorized winch to haul fish from 1,000 feet below sea level. They set out for the ice.
Petzel, along with colleague David Smith, Ph.D., and graduate student Sierra Guynn recently returned from a three-month-long expedition to Antarctica. Petzel, associate professor of physiology, has been to Antarctica before, but it was the first trip for Smith, associate professor of biochemistry, and Guynn.
Petzel received a three-year grant from the National Science Foundation to study the Antarctic teleost fish's ability to survive in the frigid waters of the Antarctic Ocean. The fish have adapted to the 29-degree water in two ways. They have a high salt concentration in their blood, which lowers their freezing point. This salt concentration is about twice that of related fish. The Antarctic fish also have an antifreeze peptide distinct to polar fish.
Petzel is comparing several characteristics of the Antarctic fish to a related fish found in the waters around New Zealand. Both fish regulate the salt content with chloride cells in their gills. He will determine whether there are more chloride cells in the Antarctic fish and how they compare in size to the chloride cells from fish found in New Zealand.
"We're interested in what adaptations the Antarctic fish have made compared to the New Zealand fish," Petzel said. "so we're sampling tissues from each and looking at how they regulate their salt content.
"The cold water from Antarctica forms a temperature barrier for fishes," Petzel said. "Those that live in the Antarctic Ocean can't live in other environments. Related fish that live around New Zealand couldn't withstand the cold of the Antarctic Ocean."
Petzel and his colleagues also are examining the way peptide hormones regulate the fish's chloride cells, and what effects warming the fish has on enzymes related to salt regulation.
"This research may help us better understand the ways salts move across cell membranes," Petzel said. "This might lead to explaining the physiology of transporting salts at the molecular level."
It was spring in Antarctica, when the sun shines 24 hours a day, but it was stormy. Winds reached 80 miles per hour, causing wind chills to dip to -40 degrees.
"It was stormier than it has been during past trips I've made," Petzel said. "I've never been prevented from doing science before, and there were several times we were restricted to staying in our buildings -- we couldn't go out on the ice. At times we had to use ropes to navigate between buildings."
Smith tells of navigating over the ice with winds whipping up snow from the surface.
"Flags posted every ten yards mark the trails," Smith said. "At one point I was driving one of these buses, which goes about 15 miles per hour. I got to the marker flag but couldn't see the next one. I drove about a minute -- it seemed like ten -- before seeing the next flag. I drove three miles that way. The winds can blow the snow 20 to 30 feet above the ice even on clear days, so you can see mountains in the distance, but can't see right in front of you."
Despite the weather, Smith was surprised that he didn't get cold. "The cold wasn't nearly as bad as I expected," he said. "The gear protected us. But what really struck me was the scenery. You see 10,000-foot mountains and volcanoes. The air is so clear. It's hard to tell the scale from photographs because there are no trees or other markers to judge by."
"I was surprised about the quality of the lab facilities," Guynn said. "We had everything we needed."
Petzel describes the working conditions in the labs there as "just like any university lab, but when you look out the window you see volcanic rock and white ice."
When they weren't working in the labs or catching fish, the researchers saw Emperor and Adelie penguins and Weddell seals and visited historical sites where explorers camped during expeditions early in the century.
Researchers live on the McMurdo base, a U.S. Navy base taken over by the National Science Foundation. Research projects are conducted in a variety of disciplines. Current studies focus on seismology, marine ecosystems, penguin demography, the ozone hole and glaciers.
"It's not as isolated as it once was," Petzel said. "There are computers connected to the Internet. With e-mail and CNN we don't feel so cut off from the world." The base also has a coffee shop, volleyball and basketball leagues, and there are Halloween and Thanksgiving celebrations.
The research team will return to Antarctica in August and will stay until December. They welcome correspondence now and while they're in Antarctica at [email protected].
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