Spotlight on Vic Dina

After the long transit that began this expedition, we have been working on the magic of science as we headed back north along our station line.

Most of the parameters we are measuring are collected and analyzed on board, so lab teams usually operate in teams of two on a 12-hour on/off schedule. Each team consists of one member who works on the day shift (noon to midnight) and their counterpart who works on the night shift (midnight to noon), so that sampling continues throughout the day and night. In my case, though, I simply collect samples from each cast to be shipped home at the end of the cruise to be analyzed for Dissolved Organic Matter at our lab onshore. This means I’m the only person in my lab and work closer to four hours on duty and 4-6 hours off (give or take). When things are running smoothly, we can complete about 3 CTD casts in a 24-hour period, and my schedule revolves around them.

I start work whenever the CTD is returning to the surface by filling out my sample logs and vials and then preparing filters to collect samples in the surface region. The filters work kind of like coffee filters—they separate larger pieces of carbon (particulate organic carbon) from the smaller pieces that are of interest to us (the dissolved carbon). These smaller organic components aid in our understanding of the role marine microbes play in the cycling of elements within the marine ecosystem. Additionally, dissolved organic carbon can alter the chemical composition and light penetration of the ecosystem. We only need to use the filters for samples collected in the upper 500 meters of the water column because the particulate matter in deeper samples does not affect our measurements. Since our first few stations of the cruise were a bit shallower while we were on the continental shelf of Antarctica, I had to prepare more filters for those casts.

Once the CTD/Rosette returns to the surface, it’s time for me to collect samples.

Now that we have all that water, we need to process samples to safely ship home. Back in the lab, it is time to treat my samples with 4M HCL acid to stop any biological processes and prepare them for shipment and analysis back on land. There is a multi-step protocol that I repeat with every sample to ensure that all samples are collected, prepared, and packaged for shipment identically. One thing scientists must be good at is problem-solving and dealing with obstacles that come up despite all the best preparation. On this cruise, I have learned how poorly things like tape or adhesives work on samples vials and containers in frigid weather conditions. Luckily, our extraordinarily well-prepared and collaborative ship crew members are always available to help when needed.

Finally, it is time for me to wrap up my shift by maintaining an electronic log as a backup for my paper logs and writing blogs like these to keep people up to date with what I am doing! In my free time, there is a surplus of books in the library, crafts to be made, and an upcoming tournament amongst scientists beginning soon!