US-France Cooperative Research: The Effect of Nutrient Limitation on Response of Marine Bacterioplankton to Solar Ultraviolet Radiation

University Of West Florida, Pensacola FL

Investigators

Abstract

0340764 Jeffrey There is now strong evidence that ultraviolet radiation (UVR) is increasing over certain locations on the earth's surface due release of halocarbons in the atmosphere. Additional halocarbons reduce stratospheric ozone resulting in an increased penetration of short-wavelength UVB relative to UVA. However, UVR is a normal part of solar radiation and organisms are exposed to significant amounts, even in the absence of ozone depletion. Most UVR impact studies have been carried out in polar areas. However, it is difficult to extrapolate results obtained in polar areas to other aquatic ecosystems because of differences in biological, physical and optical characteristics. Recent observations have demonstrated temporal and spatial variations in bacterial response to UVR. This three-year award for U.S.-France cooperative research between Wade Jeffrey of the University of Florida and Fabien Joux of the Observatoire Oceanologique de Banyuls, Banyuls-sur-Mer, France addresses the causes of bacterial response to UVR in aquatic ecosystems. The project extends the U.S. investigator's research in the Gulf of Mexico and Pacific Ocean to bacterioplankton communities of the Mediterranean Sea. The U.S. investigator has expertise in ultraviolet radiation effects on bacterioplankton in temperate lakes and the Southern Ocean. This is complemented by significant French expertise of UV effects in the Mediterranean. The project will further understanding of environmental parameters that influence spatial and temporal differences and the response of bacterioplankton to UV stress. The National Science Foundation (NSF) and the Centre National de la Recherche Scientifique (CNRS) jointly support this project. NSF provides funding for visits to France by the U.S. investigator and a graduate student. The CNRS will cover the cost of travel to the United States by the French investigator.