SPECTROPHOTOMETER AND PROFILER FOR TERC FIELD STATION AND LABORATORY, LAKE TAHOE

University Of California-Davis, Davis CA

Investigators

Abstract

The UC Davis Tahoe Environmental Research Center (TERC) has acquired and maintained a 50-year record of long-term ecological change in one of the world's iconic lakes, Lake Tahoe. Located in the Sierra Nevada mountains of California and Nevada, this is an area that has experienced, and is predicted to continue experiencing, great impacts on account of land use change, introduced species change and climate change. The two equipment items, a spectrophotometer and a profiling water quality sensor package, allow for the continuation of this unbroken data record, permit the calibration of a new generation of optical sensors, and help in the analysis and understanding of the causes and the consequences of change. The spectrophotometer, uniquely capable of use in ultra-clear water typical of Sierra Nevada lakes, will provide a regional asset for the study of aquatic ecosystems in the arid west. The long-term, publicly accessible database that continues to be acquired and archived provides an irreplaceable resource for scientists, policy makers, and the general public. The use of the data in the development of exhibits and learning programs at TERC's two public education centers in the Tahoe basin ensures that investments in science are being used to both educate and inspire school children and the general public about science, ecosystem stewardship and our threatened freshwater resources. Details of the research, monitoring and educational programs are available at terc.ucdavis.edu. The primary goal for the use of both items of equipment is to maintain and extend the long-term ecosystem record for Lake Tahoe by allowing for stable and accurate measurements to be taken with new instruments. Secondarily, the equipment can be used in a broad range of Sierra Nevada and other lakes in the region. The instruments are ideal for use in a broad range of clear, low concentration Sierra Nevada lakes. The long path-length spectrophotometer permits new areas of research to be explored through high accuracy Colored Dissolved Organic Matter (CDOM) calibrations from the spectral response of field samples. The profiling water quality sensor package (Seabird CTD) enables year-round profiling to be maintained in multiple lakes. The instruments will permit an expansion of research on CDOM and density stratification impacts in high mountain lakes. Current research is highlighting the role of CDOM both as an indicator of change and as a driver of change in aquatic ecosystems. CDOM data are urgently needed to calibrate models investigating the potential impacts of global change on ecosystem health in the next 100 years. For more information about TERC, visit the website at http://terc.ucdavis.edu/.