January 4, 2000

Aquaria tanks outside the Biology Laboratory.

It was a blustery day with winds reaching 30 knots and gusting to 40 knots. I spent the day reading and learning more about some of the science on Station with members of the BO-200-O research group. Their project is called "Ultraviolet Radiation Induced DNA Damage in Bacterioplankton in the Southern Ocean -- Photochemical and Trophic Interactions and Seasonal Patterns of UV Response." The project originates out of the University of West Florida, Center for Environmental Diagnostics and Bioremediation, in Pensacola. BO-200-O includes a disparate group of scientists whose work engages aspects of marine, micro and molecular biology. The group includes one of my roommates, Dean Pakulski, from Maine and currently working out of Florida; Jarah Meador is a scientist from the University of Texas-Houston MD Anderson Cancer Research Center in Smithville, Texas; and Karen McCrery is a doctoral candidate at Oklahoma State University at Stillwater.

As the ozone hole grows, less and less Ultraviolet (UV) radiation from the sun is absorbed in the earth's stratosphere, with the result that higher levels reach the surface. This group of scientists is trying to understand some of the impact of ozone depletion on one particular layer, or stratum, of the food chain in the coastal ecosystem of this region of Antarctica: bacterioplankton. These creatures are smaller than the phytoplankton and zooplankton that make up the next trophic level, or niche, in the food chain. Bacteria interact with these animals in ways that are poorly understood. There are several areas of intrigue for these researchers:

1. Does the interaction between bacteria and phytoplankton undergo change as a result of exposure to UV radiation?

2. How does the change of seasons, and the associated levels of UV from the sun, affect communities of bacteria? Given the dramatic differences in available daylight between summer and winter this question involves trying to figure out the life cycles and rhythms of these animals.

3. Just what happens, on a chemical level, to bacteria as a result of light intensity. From photochemical processes to chemical photoproducts, bacteria metabolize food and change the very nature of their essence based on light related phenomena.

The aim of their interdisciplinary investigations touches on many issues, from shedding light on how UV radiation affects the molecular and physiological lives of these microorganisms to the possible impact that ozone depletion may have on marine microbial communities, in general. Dean is pursuing several areas of inquiry including how photochemical processes and UV play a determining role in bacterial productivity and metabolic activity. Jarah, whose work is based in cancer research, is focused on how UV radiation physically impacts and damages the deoxyribonucleic acid (DNA), or building block of life, in phytoplankton and bacteria and how these creatures cope and heal at the molecular level. With a greater understanding of the processes and agencies of change and adaptation at the subcellular level, there may be a greater appreciation of how melanomas and other UV related tumors in humans form and, ultimately, may be treated. Karen, working in a parallel universe of molecular scale, is looking at "messenger" ribonucleic acid (RNA) and trying to understand the mechanisms of transcription that may affect repairs to UV damaged, or "kinked," areas in genetic sequences.

Here at Palmer Station, not all of the genetics work can be done. However, numerous aspects of collection and measurement are undertaken. Most of the field science involves collecting data and samples of bacteria and phytoplankton. The group also gathers a variety of other information to help piece the various pieces of their respective puzzles together: Conductivity, Temperature and Depth (CTD) surveys are taken; what is known as Profiling Ultraviolet (PUV) radiometric measurements are made. Samples are cultured on agar plates, incubated and tested for photosynthesis productivity. Bacteria are filtered and exposed to varying levels of UV radiation--both ambient UV in the aquarium tanks outside the Bio Lab and in the Lab, using a Solar Simulator. Dean affectionately refers to the simulator as, "The Beast," where bacteria are exposed to various discrete frequencies of light across the spectrum. The area of his laboratory that houses this device is protected by a black curtain and a bright, white light glows from the edges when it is running.

These scientists are studying worlds within worlds--from fluctuations in the ozone hole to the correspondent resonance in the intimate details of the life of a cell.