July 11, 2006 |
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July 11, 2006 |
Betty_Carvellas |
Jul 12 2006, 08:48 PM
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TEA Teacher Group: TEA Teacher Posts: 41 Joined: 6-July 05 Member No.: 20 |
July 11, 2006
We started a line of CTD stations last night at 9:30. Since my work with Jackie won't start until early tomorrow afternoon, I was helping Peter Lee (I'll tell you about his work in an upcoming journal) collect water from the CTD. The plan was that I would help until midnight when my roommate Rebecca would take over. We had hoped that the timing would split the work between us. Unfortunately for Rebecca, we had only completed one cast by midnight. I got a good night's sleep, and she went to bed at 4:15 AM. Splitting the work won't be an option once our first stations (five this time) of mud grabs start tomorrow. I'll be taking pictures and telling you lots more about our work once we get going. I had a chance yesterday to talk with Dr. John Nelson, Chief Scientist for the second leg of our cruise. John earned his doctorate in biochemistry and molecular genetics at the University of Wisconsin before moving to British Columbia to work with, among other things, salmon genetics. His salmon work had a management focus; he was trying to find out how the five major species are related genetically and how they're distributed. John is now a professor at the University of Victoria. I was especially interested in John's current work on board which is the distribution of zooplankton, particularly copepods, in these waters. You might remember that Rebecca and I have been helping out with the bongo nets and, if you check my journal from July 6, you'll see a picture of the nets and the copepods we collected. John started this work in 2000, and I remember the bongo nets from our 2004 cruise. He's tracking the distribution of the copepods in two ways. From one net, he preserves the copepods in formalin which preserves their structure and allows him to look at species distribution and population size. He preserves the copepods from the second net in ethanol in order to study the genetics. He can use the genetic data as a sort of "molecular clock," to trace the distribution of genetically distinct populations within a single species. Why is this information important? One example is John's work with a particularly important Arctic species of zooplankton, Calanus glacialis. He has identified a population found in the North Bering with a unique genotype which can be used as a tag to follow dispersal of this population into the Arctic Ocean. This North Bering population moves with the currents almost to Barrow where it turns into the central Arctic Ocean. He hopes to see how this distribution pattern varies with variation in ocean and climate conditions. John calls his work phylogeography or how different populations of the same species are distributed across the landscape and how geography influences their evolution and distribution. John Nelson is preparing to put the bongo nets into the water. The bongos will go down to approximately 100 meters and be towed back up vertically in order to collect zooplankton. This is what came up in the cod end of one of the bongo nets. It's lots of copepods mixed in with jelly-like material. I'm trying to wrap up some loose ends in these journals and one was from July 5 when I told you about deploying the Argo float. I mentioned that you could go online to track the data from the floats but I didn't have the website at the time. The captain was kind enough to not only read my journal but to pass along some interesting information about the Argo floats and give me the website as well. The neat thing about these floats is the international cooperation. By 2003, fifteen countries had deployed floats, and all had agreed to release real time data without restrictions. You can get more information about Argo at http://www.argo.ucsd.edu/ or http://argo.jcommops.org/ and you can access the Canadian data from http://www.meds-sdmm.dfo-mpo.gc.ca/meds/Pr...ArgoHome_e.html or you can access the global data from the Japanese Argo server at http://argo.kishou.go.jp/. Another of the day's events was a fire and man over board drill. Our station is the officers' lounge, and our responsibility is to get our life jacket from the cabinet in our room and get to the lounge as quickly as possible. I've include a pictured of Lee Cooper and Rebecca Pirtle-Levy with their life jackets on. Rebecca Pirtle-Levy and Lee Cooper are wearing the life jackets found in each of our rooms. When the alarm rings, as it did today during a drill, we all grab the jackets and move to the officers' lounge as soon as possible. |
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