Of all the tests required for the Physical Qualification (PQ) process, to be cleared to travel down to Antarctica, the one I fear the most is the blood draw. Having my blood taken absolutely terrifies me; ironically one of the samples we will be collecting from Weddell Seals during our research is BLOOD. I had lots of questions for Dr. Heather Liwanag about the techniques we will be using in the field and how the samples will be studied.

    I assumed that my skin must be must thinner than a Weddell Seal’s skin so the instruments used for blood collection must be different. So my first question for Dr. Liwanag was:

    1. Are the instruments used for blood collection different than those used on humans?

    No, it turns out the needles used and the tubes used to collect and store blood are the same. If the seals are older they have thicker blubber layers, so they require longer needles. Sometimes the harsh cold temperatures of Antarctic do affect blood sampling though. “One thing that we have to do because of the environment uses a hand-made neoprene 'cozy' that holds hand-warmers; we place the cozy on top of the needle when we are not actively drawing blood, to try to keep the blood from freezing inside the needle. It works about half the time!” Dr. Heather Liwang.

    Due to my fear of needles, I tend to get a little extra worked-up, so my doctors and I take safety precautions just in case I pass out. So my next question for Dr. Liwang was:

    2. Do Weddell Seals ever pass out while samples are being collected?

    I am a little jealous; scientists actually sedate the Weddell seals before all procedures. It seems like they try to make the seals as comfortable as possible; “To insert the flipper-mounted time-depth recorders, we also apply lidocaine, a topical anesthetic like the novocain your dentist uses.” Dr. Heather Liwang.

    After shots and blood draws I am quickly overloaded with sugar: juice boxes, popsicles, and lollipops, to bring me back to a functioning human. Since you can't hand a seal a juice box I wondered:

    3. How are the seals woke up after?

    After placing the seal pup close to its mother, reversal drugs are given and the pup is closely monitored while it wakes back up.

    Weddell seal mom and pup
    Weddell seal mom and pup. Photo by Alex Eilers (PolarTREC 2014).

    I am having my blood tested for blood count, specific elements, glucose levels, cholesterol, Hepatitis B & C antibodies, syphilis, blood type, and tuberculosis. Obviously, blood contains a lot of information, so my last question was:

    4. What details about Weddell seals are studied from their blood?

    Dr. Liwang stated, “In the blood, we are measuring hematocrit (proportion of the blood that is made up of red blood cells), number of red blood cells, hemoglobin content, and blood volume. All of these things help us understand how much oxygen the seals are able to store in their blood.”

    Scientist measuring hematocrit levels
    Analysing hematocrit levels. Photo by Alex Eilers (PolarTREC 2014).

    As I continue to work my way through the PQ process I will be comparing my anatomy and physiology to that of the Weddell seal, so stay tuned, my physical is next…

    Comments

    michelle

    Bridget, these are great questions and answers. However, I am curious why the scientists do not test the blood for more than hemocrit levels and blood oxygen. Once they have the blood, are there no other health indicators they want to study?