NWT RESEARCH DATABASE

Regions: North Slave Region

Tags: physical sciences, water quality, fish habitat, hydrology, limnology, sediment quality, bathymetry, fisheries assessment

Objective(s): BHP plans to bulk sample a prospective kimberlite pipe located beneath the waters of Gazelle. The permitting process for the bulk sampling work will require the completion of an environmental baseline study similar to those undertaken for other lakes that were similarly bulk sampled (Koala, Panda, Leslie, Beartooth, etc.). Completed baseline studies are reviewed by various government regulators and the Independent Environmental Monitoring Agency that was established for the BHP Diamond project. The Gazelle environmental baseline study will include specific investigations on water/sediment quality, lake bathymetry, limnology, catchment hydrology, fisheries and fish habitat assessment. Field data collection and observations will take about two to three days in the field. The purpose of the environmental study at Point Lake is to assess any changes to a lake where large core diameter drilling has occurred (Point Lake) to that of a similar sized lake where no drilling has occurred (Gazelle Lake).

Project Description: The Gazelle environmental baseline study will include specific investigations on water/sediment quality, lake bathymetry, limnology, catchment hydrology, fisheries and fish habitat assessment. Field data collection and observations will take about two to three days. Field staff of 3 will be transported by air to Ekati from Yellowknife. From Ekati, helicopter transport will be used to drop off the field crew and equipment at Gazelle Lake. There will be no field camp established at Gazelle. Accommodations and food each evening will be provided at the Ekati camp. A boat and motor will be stationed at Gazelle Lake for the duration of the field work. An echo sounder with transponder will be used to collect bathymetry data at 1 and 5 m contours. Portable monitors will be deployed to obtain pH, conductivity, temperature and dissolved oxygen readings. Sediment samples will be collected using an Ekman dredge. Gill and sene nets as well as angling methods will be used to collect up to 20 fish. A ponar sampler will be used to collect benthos at six locations in the lake. A Wisconsin net will be utilized to collect five phytoplankton and zooplankton samples. The investigations at Point Lake will be similar to Gazelle except additional sediment and macroinvertebrates samples will be collected.