An investigation of the factors affecting high mercury concentrations in predatory fish in the Mackenzie River Basin.

Regions: Dehcho Region

Tags: physical sciences, contaminants, mercury, fish sampling

Principal Investigator: Evans, Marlene S. (42)
Licence Number: 13007
Organization: National Hydrology Research Centre
Licensed Year(s): 2003 1998
Issued: Sep 15, 1998
Project Team: Dr. Lyle Lockhart, Jason Inkster, Katherine Gerein

Objective(s): It has recently been learned that predatory fish in some lakes in the Mackenzie Basin have very high concentrations of mercury. Health advisories have been issued. We are trying to find out why the mercury concentrations are high and where it is coming from. If we can find this out, maybe something can be done about it. We also want to find out if this is a new problem or has always been occurring.

Project Description: It has recently been learned that predatory fish in some lakes in the Mackenzie Basin have very high concentrations of mercury. This study will try to determine why the mercury concentrations are high. The researcher will fly into Cli Lake. A boat, a depth sounder and a global positional finder will be used to find out how deep the lakes in different spots. The temperature of the water, its acidity, oxygen concentration etc. will be measured. Also measure other aspects of its chemistry including mercury concentrations. Will collect small animals that the baby fish eat, small fish, and large fish and see how mercury concentration changes through the food web. Gill netting and beach seines plus some other sampling will be done to get a better idea of what lives in the lake. Bottom sediments will be sampled. Different areas of the lake will be examined.