NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region

Tags: physical sciences, lake productivity, sediment transport, biogeochemical processes, hydrological processes, delta floodplain, nutrient balance

Objective(s): Flooding and annual delivery of nutrient rich sediments are perceived to control the productivity of lakes and wetlands associated with the floodplains and deltas of major world rivers. However, there remains limited understanding of the hydrologic and biochemical interactions between large rivers and lakes. Least understood are north-flowing ice-covered rivers. If we are to anticipate potential changes to these ecosystems resulting from economic development or from global warming our basic understanding of these systems must be improved. The long-term goal of this research is to develop a model of the interacting biogeochemical and hydrologic processes that control the nutrient balance and primary productivity of lakes in the Mackenzie Delta region, and ultimately, a more general model for lakes associated with the floodplains and deltas of major world rivers. The shorter range goal is to identify & develop models of critical interlinkages between biogeochemical and hydrologic processes that are important to the ecological characteristics of the Mackenzie Delta Lakes. Specific goals for the 1999 field season are:1) Understanding how changes in the delta sedimentation regime could affect the amount of plant growth in the area and; 2) confirm the relationship between growth of aquatic plants and water clarity documented in 1998.

Project Description: The long-term goal of this research is to develop a model of the interacting biogeochemical and hydrologic processes that control the nutrient balance and primary productivity of lakes in the Mackenzie Delta region, and ultimately, a more general model for lakes associated with the floodplains and deltas of major world rivers. Work based at the Inuvik Research Centre will consist of field and lab work focused on small lakes in the Delta near Inuvik. Field work will involve day trips by boat or helicopter to delta lakes. In a cluster of 6-9 lakes just north of Inuvik along the east channel, some simple instrumentation (a light meter in a clear plastic box) will be set up for continuously measuring the transparency of the water at each of the lakes. Each lake will be visited by boat every 2 weeks to collect the light meter data, and samples of water, algae and sediments for analysis back in Inuvik. The time spent at each lake will be approximately 8 hours per visit. Another set of 20 lakes west of Inuvik and along the East Channel will be examined during late-July and August. At each lake samples of aquatic plants will be taken once during late July or August. Transportation to the second set of lakes will be by helicopter and inflatable boat.