Submitted by Ben Smith on Sun, 12/28/2008 - 07:24
Forums
Oden Antarctic Expedition 08

Hi Jeff,

-Your "iceberg panorama video" is remarkable! Thank you. I also enjoyed the video piece with Julia Diaz from Georgia Tech and reading the questions from Lollie. Jeff, do you know if Julia and/or other Oden researchers are looking at phoshporus absorption(phosphate uptake and phosphorus content per unit body mass) in Antarctic marine life that is brought up in the plankton nets? A question related to this, -has plankton-net sampling of marine invertebrates been done at various points along the journey to Antarctica in order to have comparison samples? I am curious as to whether Oden researchers are currently measuring carbon dioxide levels in Antarctic waters in an attempt to look at 1.) possible ocean acidification that could result, 2.)decreased phosphate absorption by marine organisms and 3.) possible increased photosynthetic activity. Jeff, as a last question for now, are you aware of any Oden research looking at changes in nutrient flux or movement (perhaps) due to reduced pH, possibly leading to changes in microbial communities?(has there been any sediment sampling of microbial communities in coastal/shelf areas?) I am reminded of the "Have You Thanked a Microbe Today? bumper sticker :-)

Jeff, Thanks again for sharing your PolarTREC experience! Peace & Happy New Year, Ben Smith & his Environmental Science students at Peninsula High School California

Mon, 12/29/2008 - 10:09

Jeff Peneston

Ben,These are such great questions that I went to the biologists and chemists on board to get the answers.  Let me respond to them in order.
Q: Jeff, do you know if Julia and/or other Oden researchers are looking at phosphorus absorption(phosphate uptake and phosphorus content per unit body mass) in Antarctic marine life that is brought up in the plankton nets?A: No one on board is doing plankton tows or collecting marine life from the bottom or the water column other than Julia and she is only sampling so that she can identify the diatoms present.  We have several scientists who are measuring the nutrient fields.  However those measurements are generally of the levels and ratios of dissolved nitrogen, phosphorous and silica in the water column.  They can then infer the effect of nutrient uptake or discharge by the plankton at various depths.
Q: has plankton-net sampling of marine invertebrates been done at various points along the journey to Antarctica in order to have comparison samples? A: No
Q: I am curious as to whether Oden researchers are currently measuring carbon dioxide levels in Antarctic waters in an attempt to look at 1.) possible ocean acidification that could result, 2.) decreased phosphate absorption by marine organisms and 3.) possible increased photosynthetic activity .A:  Carbon dioxide levels in the seawater, sea ice and brine are all being measured by the ice research team.  Their primary concern is to characterize the gas fluxes between the ocean and the atmosphere.  Increases in CO2 can lead to acidification but the biochemists on board don’t anticipate that it would lead to changes in phosphate uptake by microorganisms.
Q: are you aware of any Oden research looking at changes in nutrient flux or movement (perhaps) due to reduced pH, possibly leading to changes in microbial communities?A: Two of the scientists are measuring nutrient levels at various depths and comparing them to the currents that move water masses up and down column however no one is specifically relating that to pH or studying microbial communities other than those in the sea ice.
Q: has there been any sediment sampling?A: No, because the Oden is not a particularly good platform for coring.
I hope that I have covered your questions and I agree with your interest as a teacher to get students to understand the importance of microbial life.  It is easy to sell stories and images of penguins but where would they be without plankton?
Take care,
Jeff

Mon, 12/29/2008 - 17:22

Ben Smith

Hi Jeff,A Big Thank You for your detailed reply and for taking the time to discuss the questions that I had posed with the other researchers on board. Your work is outstanding Jeff!
-Thank You.
Happy New Year.
Ben Smith and his Environmental Science Students at Peninsula High School
California