Shellabear Lake (75'N, 113'W)

 

Researchers: Scott Lamoureux, Hilary Dugan

 

The research at Shellabear Lake focuses on the chemical evolution of a hypersaline coastal lake in the Canadian High Arctic. Shellabear Lake is located near Shellabear Point (75'N, 113'W) on Melville Island, in the Canadian Arctic archipelago. In the Arctic and Antarctic, many coastal lakes which originally contained ocean water, have become hypersaline (saltier than ocean water) following isolation from the ocean. The few studies that have examined the origin of hypersalinity in polar lakes are equivocal in their findings. Consequently, it remains disputed as to what processes are critical in the development of brine in polar lakes, and how coastal lakes evolve chemically.

 

This study investigates the physical and chemical processes in a coastal hypersaline lake that has a seasonal tidal connection. The goal is to understand the daily, seasonal, and annual dynamics that control the physical structure of the lake, and determine what influences salinity, density, and oxygen stratification. Elucidating the role of brine rejection, tidal forcing, and groundwater input are central to the research.

In 2009, a six week intensive sampling program was undertaken at Shellabear Lake. In-situ analyses of physical parameters and water sampling for ionic composition, sediment concentration and total organic carbon, were performed daily. A test study using radon concentration to infer groundwater discharge was also conducted. In addition, a moored CTD instrument deployed in 2008, which records temperature, salinity, and depth, was successfully recovered from the lake. In the Canadian Arctic, where most field work is performed in the summer, these data present a unique year-long record of physical changes in the water body beneath the ice cover.