Biogeochemistry of lakes in the Mackenzie Delta

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NRS funding is requested to support my on-going arctic research Biogeochemistry of Lakes in the Mackenzie Delta. This program has been on-going since 1991 and was supported (NSERC-DGP) during the past 4 yrs at $40k per yr.  The long-term goal of this research is to develop a biogeochemical model for lakes in the Mackenzie Delta, and ultimately, a more general ecosystem model for floodplains and deltas of major world rivers that will facilitate assessing the effects of multiple stresses on rivers resulting from global change. The Mackenzie Delta contains 45,000 lakes and is representative of floodplain lakes among major river deltas of the circumpolar arctic, a region of the world where climate is changing more rapidly than anywhere else. Specific goals during the next 5-yr term include assessing (1) sources and fates of dissolved organic carbon in delta foodwebs; (2) foodweb controls on plankton heterotrophic nanoflagellates (HNAN) in delta lakes; (3) photochemical production of H2O2 and biolabile-DOC in delta lakes; (4) responses of aquatic bacteria to photochemical effects and high pH in delta lakes; and (5) further work on delta effects on river nutrient outflow to the Beaufort Sea. Our capability to hydraulically model the effect of the Mackenzie Delta on riverine outflow to the Beaufort, crucial for modeling the response of the Arctic Ocean to climatic warming and changing river inflows, will be pursued independently via IPY funding sources. The success of these goals depend on availability of NRS funds to offset the substantial and increasing users fees associated with basing this work at the Inuvik Research Centre (facility essential for proposed work) and the high costs of travel to this arctic location. Total expenses eligible for NRS funding are $34,900 per yr, and would otherwise consume the majority of DGP funds requested for this program.  NRS funds will also contribute to expanded technical training of highly qualified personnel (including 2 PhD and 3 MSc students plus 5 field assistants through the next 5 years) in arctic-based research.