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Principal Investigator: Wade H. Jeffrey, PhD Support Agency: National Science Foundation Location of Study: Southeastern Pacific Ocean |
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Principal Investigator: Wade H. Jeffrey, PhD Support Agency: National Science Foundation Location of Study: Southeastern Pacific Ocean |
In July and August 2000, the RV NATHANIEL B. PALMER made a
transit from Punta Arenas, Chile to Port Fourchon, LA approximately
northward along 85° W until it approached the Panama canal.
This provided an increasing solar irradiance field during the
transit north in a very short period of time. Planktonic communities
along this transect have been exposed to very different incident
solar irradiance. It is expected that they will have adapted to
be able to tolerate the ambient irradiance to which they are exposed.
Water samples were collected twice daily at approximately 2 degrees
of latitude intervals using pumps, a CTD rosette, and plankton
nets.
The objectives are either a continuation or a direct complimentation
to many of the objectives of our current Antarctic work along
the Palmer Peninsula. We have been focused on elucidating the
response of marine bacteria to changing UVR conditions brought
on by ozone depletion. During the cruise, we examined the effects
of changes in UV response brought on by increasing UVR in a latitudinal
gradient. Much or our current work is examining community response
to UVR which requires an investigation into the molecular diversity
of the microbial communities. We will advance that work by also
considering molecular diversity in functional genes. The objectives
of this project are: (i) Examine latitudinal response in
microbial communities to ultraviolet radiation; (ii) Examine the
relationship between UVB induced DNA damage and inhibition of
bacterial production; (iii) Compare the relative levels of UVB
induced DNA damage in various planktonic size fractions including
viruses, bacteria, and small eukaryotic plankton. (iv) Examine
the relationship between solar intensity and induced DNA damage;
(v) Examine concentrations of UV absorbing compounds in planktonic
communities along a latitudinal transect; (vi) Examine molecular
diversity of genes important in biogeochemical cycles.
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