26 January, 1997
From McMurdo Station:
Lets go back to the question that I asked of you soon after my arrival. Does the tide cause movement in the Ross Ice Shelf? The answer is yes. Using GPS, the ice shelf has been measured at over one meter change in position due to the tide from the ocean.
I asked you several questions about experimental design. Some of the things that I must consider within the rotifer experiment include the following: When do rotifers feed in their natural habitat? Not all rotifers need to take up the fluorescent material for the experiment to be valid. After determining that the rotifers will take up the food, I must know the concentration of food available in their natural environment. I also must know what concentration of fluorescent parcticles I am feeding to the rotifers. It would be best to do the experiment in their natural habitat, or in conditions that match their environment. This means matching the light and temperature of their habitat. We considered placing the experiment into the actual pond, however, results show that rotifers take up the food almost immediately after the fluorescent objects are added so there is no time to put them into the lake. I keep the dish cold since the water temperature is about 1 degree celcius. Light is a problem for several reasons. To see using the epifluorescent microscope, the lights must be off in the microscope room. The room is dark. If the slide is on the scope too long, it heats up and kills the rotifers. I did find that even if they are killed, one can still see the beads or fluorescence in their guts.
One thing I did notice during this work with rotifers is that many of them had live babies feeding inside of them. Four out of five rotifers had at least one live young inside her body; many had two live babies who appeared to be feeding on her. Reference books comment that the usual pattern of reproduction is egg laying for rotifers, however sometimes they are known to have live young. I think I have found the exception and the rule for Antarctic rotifers. This may have an impact on the feeding rates of the rotifers. Will their reproduction "season" influence my feeding experiment?
Today I let the rotifers that I brought from the dry valley settle in a light incubator. Tomorrow I plan to try some additional feeding trials with these samples to see if I can get similar rates to support my existing data.
On another note, If you would like to see more pictures including some of the helicopters, check out TEA teacher Bill Philips's web page, He has a digital camera and was camping in the next valley over from my field camp. He has quite a few pictures of the area that will let you know better what the dry valleys look like.
ANOTHER WEB SITE HAS SOME MORE PICTURES OF THE LAKES INCLUDING VIDEO OF THE DIVES UNDER THE ICE. THIS SITE HAS TEXT FOR THE PICTURES AS WELL. LOOK FOR HTTP://WWW.RESTON.COM/ASTRO/LTER The pics on my web page came from this site. Dale, the diver and photographer, does a wonderful job sharing his work on his web page.
To understand more about the training that everyone new to the ice must gain, check out TEA teacher Carol Bennett's web page. We all have received the same training have experienced similar reactions.
Tonight Sir Edmond Hilery, Prime Minister of New Zealand will be giving a talk here as part of his visit. He is a former Antarctic explorer. I plan on attending this talk, due to start soon. I expect there to be a crowd, so I must leave you now.
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