9301833 Siver This U.S.-Argentina Cooperative Science award will support the collaboration of Peter Siver of Connecticut College and Maria Vigna of the University of Buenos Aires, Argentina. The project aims to examine the biodiversity and ecological requirements of the algal flora Chrysophyta in the Parana River system. The Chrysophyta, especially the scale-bearing species, represent one of the most important bioindicator groups of aquatic organisms. Their biodiversity in subtropical waters is poorly understood. This project, an initial phase of a large-scale study, will describe the composition and distribution of species along environmental gradients for the river's deltaic region. The flora will be compared to other subtropical, tropical, temperate, and arctic regions in order to understand the spatial distribution of this algal group. Organisms not known to science will be identified and described. Both the U.S. and the Argentine sides will benefit from development of a database for use in paleolimnological inference work aimed at understanding the effects of human disturbances on aquatic resources. ***
