Aquatic Sciences Meeting, Albuquerque 2001

SS21 Ultraviolet Radiation and the Aquatic Biota (Disciplinary Connections)

Date: Wednesday, February 14, 2001, Time: 12:15:00 PM

Location: Galisteo

Jeffrey, W, H, University of West Florida, Pensacola, FL, USA, wjeffrey@uwf.edu

Pakulski, J, D, University of West Florida, Pensacola, FL, USA, jpakulski@uwf.edu

Kase, J, P, University of West Florida, Pensacola, FL, USA,

Durkin, S, S, University of West Florida, Pensacola, FL, USA, sdurkin@uwf.edu

Scott, K, , University of West Florida, Pensacola, FL, USA, kls10@students.uwf.edu

SPATIAL AND SEASONAL VARIATIONS IN MARINE MICROBIAL COMMUNITY RESPONSE TO ULTRAVIOLET RADIATION NEAR PALMER STATION, ANTARCTICA AND THE SOUTHEAST PACIFIC OCEAN

Marine bacteria play a central role in the biogeochemistry of the ocean and are affected by ultraviolet radiation (UVR). Variations in zenith sun angle, ozone concentrations and daylength influence the quality and quantity of UVR reaching the Earth’s surface. We investigated the response (leucine and thymidine incorporation rates) of bacterioplankton to seasonal and latitudinal changes in UVR using a full spectrum lamp as a constant source of artificial sunlight. Optical filters were used to assess the affect of UVB, UVA and PAR. Seasonal samples were collected near Palmer Station between September 1999 through January 2000. Latitudinal response was examined in surface waters collected in the Southeast Pacific Ocean between 41 degrees south and 4 degrees north during July and August 2000. Seasonal samples collected near Palmer Station indicated decreasing sensitivity of bacterioplankton to UVR with increasing daylength. Geographical trends in the response of bacteria to light exposure were also observed. These trends were complex and appeared to be related not only to latitudinal variation in light intensity and wavelength but to variations in chlorophyll and bacterial growth rates as well.

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Aquatic Sciences Meeting, Albuquerque 2001

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