Week 3 Blog
Lance Brockie


This week was a little different from the activities that I’ve been involved with so far involving this internship. On Tuesday, we participated on a working cruise aboard the R/V Centennial, which is a research vessel based out of Friday Harbor Labs. The purpose of this cruise was to conduct depth profiles utilizing the Conductivity, Temperature, Depth Sensor (CTD), as well as to collect water samples at various depths which would be used to measure the chlorophyll and dissolved oxygen levels back at the Shannon Point Marine Center Lab.

Each intern who participated was assigned a specific task to perform aboard the vessel. Another student (Mike Murphy) and I were assigned with lowering the CTD into the water as well as bringing the CTD back aboard once it made its descent to the bottom and back to the surface (see picture). Once the CTD was back aboard, I was then tasked with collecting water samples from designated niskin bottles which are located on the CTD. Once the BOD bottles were filled I then added the Winkler reagents (Manganous chloride, and Alkaline iodide) to each sample and stored them to be analyzed later at the Shannon Point lab using the Winkler Method.

This was a great learning experience not only for me but I would have to say all the other interns as well. Once learning about the CTD and visually seeing what this instrument measures in the water column (see figure below), I now have a greater understanding of what is going on at various depths of the ocean. I consider myself very lucky that I got the opportunity to learn how this piece of equipment operates and was able to work with it firsthand. I would have to say that this week has been the highpoint of this internship thus far, and I’m certainly looking forward to the next time we get to participate on another cruise.