July 10, 2006 Options

[Betty_Carvellas]

July 10, 2006

Brianne Kelly is a Masters student at the University of Victoria, working with Dr. Diana Varela. She's on board ship for the first time and she's finding that doing science at sea is very different from on land. As she says, 'It' a steep learning curve." From what I've seen in the time we've been out, she's learning very fast. Briann is interested in primary productivity from the phytoplankton (tiny aquatic plants) and in nutrient cycling. Temperature and nutrients are two factors that determine which populations of phytoplankton are found in which places. And, since phytoplankton use photosynthesis to convert the sun's energy for most of the rest of the organisms in the food chain, their presence is extremely important.

Brianne takes water from the CTD bottles once every two days, getting water from ten depths each time. She'll filter some right away and incubate the rest in two tanks out on the flight deck. She's looking primarily at diatoms (beautiful phytoplankton with silica shells) and, since the North Pacific is high in nitrates and low in the iron that diatoms need, she must allow them to incubate for 48 hours in order to get a measurable result. Once she has filtered her samples, Brianne will freeze them for later silica and isotope analysis. Since diatoms have silica in their shells, they are the primary silicate users and thus they dominate the marine silica cycle. Bacteria will sometimes "eat" the protective coating over the diatom shells, exposing the silica shell which then dissolves. That silica is considered to be recycled. In colder waters, the bacteria are less active, the protective coats are less vulnerable, and more silica sinks to the sediments along with the dead diatoms. In addition to her primary filtering station, Brianne also has a smaller station where she spikes her samples with an isotope tracer before filtering. Analysis of how much of the isotope is taken up by the diatoms yields information about carbon and nitrogen use overall. By pooling all of the data, Brianne and her adviser will better understand the nutrient dynamics along our transect.


Brianne Kelly, a Masters student at the University of Victoria, is interested in primary productivity (from the phytoplankton) and nutrient cycling. She spends most of her time collecting and filtering water to get samples to take back for analysis.

In my journal of July 10, I told you a little about the engine room on board the Laurier and about Second Engineer Laurie La Plante. The first pictures I took of Laurie were fuzzy, and then my camera batteries died. I finally have two good pictures of Laurie. I took one in the Master Control Room of the ship's engine room and my roommate Rebecca took the other while I was reviewing my journal with Laurie before posting it.


I took this picture of Second Engineer Laurie La Plante in the Motor Control Room of the Laurier.


Whenever I write a journal about someone, I always check it with them before posting to make certain I have all my informataion correct. Rebecca Pirtle-Levy took this picture of me and Laurie La Plante as we looked over the draft of my journal.