This study will contribute to our understanding of the full range of natural "sunscreens" that marine organisms have to protect themselves against ultraviolet (UV) radiation. With concerns about increased incident UV caused by global ozone depletion, it is crucial to evaluate the ecological effects of this atmospheric phenomenon on biological systems in Antarctica. Mycosporine-like amino acids (MAAs) absorb radiation from the UV portion of the solar spectrum and are commonly found in marine species. Scientific information obtained on MAAs will further our understanding of how marine organisms deal with UV exposure and continue to function within their ecosystems. Little is known about the regulatory mechanism of MAAs production in phytoplankton or the mode by which such compounds accumulate in animal tissue. Dr. Karentz proposes to determine if changes in MAA concentration represents an adaptive response to UV exposure and to examine the possible relationships between MAA content in primary producers and their consumers. The research will be accomplished by comparing MAA concentrations in selected algal and invertebrate species at different times during the annual springtime gradients of increasing day length and ozone depletion, during different life cycle stages, and under controlled light and food conditions.
