CHARACTERIZING SHORT-TERM (1970-PRESENT) LAKE CHANGE IN THE HIGH-MOUNTAIN TROPICS AND AMAZON OF ECUADOR

Ecuador encompasses a wide variety of unique ecosystems ranging the high Andes mountains to the lowland Amazon forest. The last approximately 40 years witnessed major shifts towards a more urbanized country. This trend is accompanied by increasing global temperatures and associated climatic changes. Lakes are sensitive to changes in their watershed; increasing temperatures and nutrient influxes from urbanization lead to eutrophication risk. These lakes provide water to surrounding cities making it important to understand how these lakes are changing on short-temporal scales. Dr. Miriam Steinitz-Kannan collected phytoplankton samples from over fifty Ecuadoran lakes in the late 1970’s to the 1980’s. Phytoplankton, specifically diatoms, are very sensitive to changes in the lake system. Sampling of the diatom community from twenty-six lakes was performed in July 2017 providing a unique opportunity to evaluate environmental change over the last 40 years. Diatom counts and water chemistry analyses reveal that some lakes of the high mountain Andes are experiencing increases in Discostella stelligera, while other high mountain lakes are dominated by Tabellaria. The lowland Amazon lakes are dominated by Aulacoseira species. Overall, the lakes of Ecuador have experienced change within the last forty years. Longer temporal data (sediment cores) are being analyzed to evaluate tropical lake resilience to environmental change.