PI: Laurel Saito, University of Nevada Reno Co-PI: Eric Marchand, University of Nevada Reno Diversion of Amu Darya River water to feed irrigation canals has resulted in greatly diminished flows as the river approaches the Aral Sea. One of the most poorly supplied provinces in Uzbekistan in terms of drinking water is Khorezm, which is also one of the most agriculturally productive regions of Uzbekistan. A potential water resource in the Khorezm province that remains largely unstudied is a series of lakes that receive agricultural runoff in natural depressions in the landscape. The North Atlantic Treaty Organization (NATO) has funded a project with an overall study objective of enhancing knowledge about the potential utility (or detriment) of irrigation lakes in the Khorezm region, and the impacts of anthropogenic activities on the sustainability of the aquatic ecosystems of these lakes under its Science for Peace program. Results of organic contaminant sampling from that study indicate very low concentrations of organochlorine pesticides despite a history of heavy pesticide usage prior to 1991. We will perform lake coring and microbial experiments to address hypotheses regarding processes of pesticide degradation in the lakes, and the ecological sustainability of the lakes. Furthermore, the NATO project funding does not include coverage of salaries or stipends for participants based in NATO countries (the United States in this case). Thus, this project supports a U.S.-based graduate student and a part-time statistical technician to collaborate with young Uzbek scientists working on the NATO project. The intellectual merit of the proposed activity includes the new scientific knowledge gained by understanding the fate of organic chemicals in these previously-unstudied small lakes impacted by irrigation runoff, which could lead to implications for lakes in other parts of the world. Although the project is focused on a small number of the lakes in Khorezm, the study has implications for similar lakes in areas of heavy agricultural use. Past and present use of pesticides can result in detrimental impacts on aquatic ecosystem sustainability, but these lakes may provide an example of lakes that have passed a threshold so they can once again become productive ecosystems both ecologically and economically. This could provide guidance for similar lakes in other parts of the world. Because these are shallow lakes that have variable sediment compositions, and there are limited coring resources in this remote environment, we will develop low-cost effective methods for recovering lake cores that will be useful for others who wish to do lake coring in shallow lakes in developing countries. Additional broader impacts include the excellent and unique opportunity provided by the project to train students for international collaboration and research. The NATO project already involves excellent, bright young scientists in Uzbekistan, and the inclusion of a young counterpart in the United States will enable the interaction of a new generation of young scientists. Thus, this research will enhance international linkages between Uzbekistan and the United States for water resources and ecosystem management.
