July 5 & 6, 2009

7-5,6-09

I think it’s safe to say that at this point the regular blog schedule has gone out the window. Because of our cruise path timing, a large collection of work has presented itself as we arrived at the spring phytoplankton bloom site. We were able to get another sediment core, courtesy of Dave Shull and company, and collected a hundred liters of water for a phytoplankton degradation experiment.

After our usual nightly krill tow the nets returned from the water covered with phytoplankton. While everyone else was a little annoyed to have to deal with the slimy algae all over the nets, I was ecstatic! “Yes!” I thought “more material to observe in our degradation experiment! Cha-ching!” The CTD cast returned with ten Niskin Bottles, ten liters each, for us to use for the degradation. Three twenty liter carboys were filled with seawater from six of the Niskins. The additional four of Niskin bottles were filtered to about a half a liter each and added to two of the carboys to increase the amount of phytoplankton in the carboy. The carboys were then placed in a cold room at a realistic environmental temperature.

The cold room was nicknamed “The Red Light District” for all of the riskay science going on inside, and that fact that the lighting is actually red to limit the amount of light on sediment samples. Despite this, the carboys are covered with garbage bags to prevent the phytoplankton from photosynthesizing (if they continue to harvest any light they will continue to grow and we will not be able to observe any degradation in the time remaining in the cruise). We will take samples of water from each carboy at various time points for the remainder of the cruise to observe how the protein in the carboys degrades. Do certain classes of protein degrade faster than others? Do proteins degrade differently during different seasons? (A similar degradation experiment was conducted on the spring cruise by Rachel and our advisor, Rodger Harvey). Very interesting stuff for us marine organic geochemist types.

The whole process required a lot of water filtering (and little sleep) over the last day and a half, but it will prove to be very useful once we get the samples back to the lab in Maryland for analysis. Rachel’s performance was by far the most impressive, as she stayed awake for nearly two days strait organizing the filtering effort and analyzing dozens more krill eyes at the same time. A true champion at crunch time.

Once we had finished all of our experimental setup and preliminary sampling/filtering, the sediment core was available for slicing. The busy schedule did not yield any time for pictures of the sediment processing, but we encountered a small worm in the surface sediment and a small sea star (about 2 inches across) a few centimeters down the core. The core was taken from water 135 meters deep. I am certainly accustomed to seeing worms and sea stars in tide pools, but not hundreds of feet below the surface. It just goes to show how diverse the life is in this dynamic system.

-Eli