This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Little Gaynor Lake is a small closed-basin lake near Boulder, Colorado. The lake is relatively saline and supports a dense population of cyanobacteria, predominantly of the species Anabaenopsis elenkinii. The Center for Limnology, CU-Boulder, has been monitoring the water quality of the lake over the past year and has reported unusually high concentrations of soluble carbon in water samples (~ 100 mg / L). The high organic content of the lake is of interest as it could be contributing to the dense algal population. To further investigate this topic, the Center for Limnology and the National Magnetic Resonance Facility at Madison (NMRFAM) are conducting a molecular analysis of carbon found in Little Gaynor Lake. The scope of this project includes metabolic analysis of Anabaenopsis elenkinii and soluble carbon found in cell free filtrates of lake water.