July 15 - 2005 Options

[Betty_Carvellas]

July 15, 2005

We started our mud work right after dinner last night. Although it wasn't exceptionally cold, the weather had changed, and it was overcast with a cold drizzle. Fortunately it was still light out when we completed our first three stations at 2 AM. That always makes it easier. We're lucky this year. Even though this first line includes five stations, Bill's mooring work comes right in the middle. That gave us all a nice break and a chance to sleep before doing the last two. I'll tell you more about the mud work in a future journal when I've had a chance to take some pictures in better weather. In the meantime, check out the picture of the mooring stretched out on deck and ready to be deployed once we were on site. I took the picture yesterday evening, and by the time I woke up this morning, Bill had been able to retrieve the mooring set out last year as well as deploy the other two.



I've mentioned that the science team consists of ten people, and I've already told you about some of the scientists and the work they are doing. Three other members of the team play an integral part in the science that's done on board. Jeri Butcher, my roommate, is from Bentley, Alberta. Jeri majored in marine biology as an undergraduate at Dalhousie University in Halifax, Nova Scotia, and she knows that she wants to work on the ocean. This is her second cruise as a volunteer, and this time she's working with Bon van Hardenburg, assisting with the CTD casts. She's learning how to operate the data acquisition system and is involved in the all the record keeping that goes along with the CTD work. Mud work and moorings are limited to certain stations; the CTD goes in the water at every station! Between my mud work and Jeri's CTD work, we keep very unusual hours in our room.



I've worked with both Ari Balsom and Rebecca Pirtle-Levy on previous cruises, and it's great to work with people who are so organized and competent. Rebecca is a Masters student in Ecology and Evolutionary Biology at the University of Tennessee, Knoxville. Ari recently completed her Masters work in the same program. Both work with Jackie Grebmeier, Ari as Research Coordinator, and Rebecca as research assistant. I'll give you an outline of the work they do, and explain it in more detail in a future journal. I'm still waiting for a nicer day to take some pictures of the mud work.

A "mud" station starts with the CTD cast. Either Rebecca or Ari will take water from the CTD while the other gets set up for the mud grabs and cores. They take water for chlorophyll-a analysis, oxygen-18 (see my journal from July 10), and nutrients. While the oxygen-18 and the nutrients are preserved for later analysis, Ari and Rebecca will process the chlorophyll-a on the ship. Chlorophyll-a is found in the cells of plants, and is an important indicator of "productivity," or the availability of food in the water. After filtering the water, they place it in glass vials in the freezer, for one hour, to break the plant cells and release the pigments. They then extract the chlorophyll-a by placing the filters in acetone in the refrigerator. Twenty-four hours later, they will take chlorophyll-a readings (measurements) from each of the twelve samples with a fluorometer. They'll also take chlorophyll-a readings, after twelve hours, from the mud samples from both the van Veen grab and the Haps core. The tough part about all this is that, once we get going, the samples start to back up, and Ari and Rebecca are up at all hours, not only for the CTD casts and the mud work, but for taking chlorophyll readings.