Science Digest

2010
 
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In 2010, our research team was only at Palmer Station for 25 days. This meant we spent more time in the field and less time in the laboratory than in previous years. Here’s a summary of what we have learned so far, and what we’ll be doing next.

Does the amount of daylight tell Belgica it’s time to get ready for winter?
Most of the work on this question will be done in our home laboratories. While we were in Antarctica, however, we measured natural light intensity and took samples of adult and larval Belgica for later analysis. Although there was nearly constant daylight in January, the short period of low light intensity between sunset and sunrise is probably enough to help Belgica keep track of time. During the day, the intensity of light varied a lot because of clouds.

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Are Belgica from different islands genetically different from one another?
Belgica has no wings, so probably doesn’t move from island to island very often. We suspect that island populations are genetically separated from one other, and may even be in the early stages of speciation (the formation of new species). To test this hypothesis, we collected larvae from distinct geographic locations on Cormorant, Humble, and Dream Islands, and will be looking for evidence of genetic differences with the help of a scientist from the Ohio Agricultural Research and Development Center, in Wooster, Ohio.

 

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How well does Belgica handle multiple freeze-thaw cycles?
Previous studies have focused on how Belgica handles one stressful event, such as drying or freezing. In nature, however, Belgica has to deal with fluctuations between stressful conditions and more “comfortable” conditions. We did experiments to examine how well Belgica can survive up to five freeze-thaw cycles.

We found that survival decreased as the number of freeze-thaw cycles increased. In other words, more than 80% of the Belgica frozen and thawed just once lived, but fewer than 50% of the Belgica frozen and thawed five times lived.

 

As climate changes in the Antarctic Peninsula, we expect to see more freeze-thaw events each year than we do now. (In the winter, more thaws could occur due to warm weather or a lack of insulating snow cover. In the summer, more freezes could occur during storms.) Our initial results suggest that repeated swings between high and low temperatures could be bad for Belgica.

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Do ATP levels go up or down when Belgica is exposed to cold?

Another investigation we started at Palmer, but will finish in our home labs, is on ATP levels in Antarctic invertebrates. Adenosine-5’-triphosphate, or ATP for short, provides the energy necessary for cells to carry out day-to-day functions. Many warm-climate adapted ectotherms have less ATP in their cells when they are exposed to cold. However, recent research on ice worms (which live in glaciers in places like Alaska and northern British Columbia) suggests that cold-climate adapted species may show the opposite trend. We will investigate whether Belgica, Cryptopygus antarcticus (a species of springtail), and Alaskozetes antarcticus (a species of mite) show higher or lower ATP levels when they get cold. If we see the same pattern in the Antarctic animals as in ice worms, it will suggest that the ability to provide a source of energy to the cells may be a requirement for life in the cold.

For a list of other questions our team will be investigating, please read this blog post from Palmer Station.

 

- Nick Teets, Yuta Kawarasaki, and Juanita Constible


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