NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region

Tags: aquatic ecosystems, biology, fish, habitat, seismic activities, delta lakes, fish abundance, species abundance

Objective(s): The proposed Fall 2001 Mackenzie Delta Aquatics Survey is a short-term reconnaissance/assessment of aquatic habitats in selected lakes that may be affected by seismic activities during winter 2001-02. The objective of the study is to obtain environmental information on a sub-sample of fish-bearing lakes to aid in decision-making by operators and regulatory agencies within the ISR. The data to be collected will represent a sample of fish-bearing lakes associated with this year's operations, recognizing the degree of variability between lakes.

Project Description: Selection of lakes for this program was based on: size (diameter/depth); fish over-wintering potential; connectivity with other waterbodies; and the likelihood of intensive (3D) seismic activity occurring within the lakes during the winter of 2001-02. A total of 6 lakes have been identified for inclusion in the survey. Three alternate lakes have also been identified in the event that those selected for the survey are deemed unsuitable for the study. The survey crew and equipment will be transported to the survey lakes by floatplane. The recording and sampling in each lake will be conducted using an inflatable boat. Parameters related to the potential for fish and fish habitat will be assessed during the field program. This study will also provide background information as to the potential affect of seismic activity on waterbodies. The parameters that will be assessed are : (1) Dissolved Oxygen (DO); (2) Carbon Dioxide (CO2); (3) pH; (4) Conductivity; (5) Total Suspended Solids (TSS); and (6) Nitrogen. Measurements will be taken on an established daily schedule to minimize variation due to time-of-day effects. In addition, stream flow measurements, bathymetric surveys, and digital imaging will be completed for the selected lakes. Water velocity and total discharge will be calculated at inlets and outlets of the lakes using topset flow meters. Bathymetric profiling will be conducted with the use of an echosounder that transmits and receives signals from the substrata of the waterbody. Due to the non-invasive nature of the lake survey, and following the implementation of mitigative measures, no negative significant residual impacts are anticipated. Protection measures have been designed to mitigate potential environmental impacts of the fieldwork program. Flight lines will avoid known cabin locations and the aircraft will maintain altitudes above 300m between sample locations. To minimize disturbance of local people, the aircraft and crew will avoid lakes with evidence of current use. An Inuvialuit Wildlife Monitor will accompany the survey crew at all times to identify and address any wildlife issues that may arise. All equipment and any garbage will be returned to Inuvik for proper disposal. No fish will be captured or handled during this program.