A Dissolved Oxygen Model to Help Manage Water Use in Arctic Lakes

Dissolved oxygen (DO) in arctic lakes is a key factor for winter survival of fish. Management of water use from lakes indirectly attempts to manage DO through volume limitations of water used on an annual basis, or during the winter ice-cover season. The relationship between water volume, DO budgets, and extraction of water through pumping has historically not been well understood or taken into account for managing water-extraction volumes and timing of extraction. DO budget modeling tools can be used to help predict the amount of DO available at the end of winter. Factors such as bathymetry, DO consumption in the water column and lake sediments, and timing of recharge should be taken into account in using a DO management model for regulating lake water use. The model being presented was developed to describe DO concentrations as they are affected by bacterial respiration, and freezing exclusion. Further development will include metals reduction and removal of water during periods of ice cover. The model was developed with data taken from 2 natural arctic thaw-lakes and 2 flooded gravel mine-site locations on the North Slope of Alaska.