NWT RESEARCH DATABASE

Tags: physical sciences, fish, biomass, mine development

Objective(s): To remove the majority of fish from within the A21 dike and transfer into Lac de Gras to allow for dewatering and construction to occur.

Project Description: The purpose of this project is to remove the majority of fish from within the A21 dike and transfer into Lac de Gras to allow for dewatering and construction to occur. The General Fish-out Protocol separates fishing effort into two phases. The Phase 1 fishing effort will begin with short duration gill nets and trap nets to target live release of fish into Lac de Gras. Fish captured will be transported to a processing station located on the A21 dike. Fish will be counted and then transferred to a holding pen prior to release. A one hour maximum set time with the intent to maximize fish survival. Fish mortalities will be processed and frozen for distribution to local communities. A small number of trap nets will also be deployed and checked daily during the Phase 1 fishing effort as catch rates begin to decline. Phase 1 will end when either no large-bodied fish have been captured in 48 hours when all available nets are used in lake or when 80% of the estimated cumulative biomass is removed from the lake. Phase 2, the final removal phase, will occur immediately after confirmation by the Department of Fisheries and Oceans of the successful completion of Phase 1. The objective of Phase 2 is to deploy a range of fish sampling gear with increasing levels of effort to target removal of all remaining fish in the A21 diked area, including small bodied species and juvenile fish that may have been missed during gill net sampling in Phase 1. During the initial stage of Phase 2, a range of sampling gear, including the continuation of gill netting and trap netting, as well as minnow trapping, set lining, and angling, will be utilized to determine success of each sampling method. Targeted fishing locations will be identified based on areas with the highest catch rates. All fish captured during Phase 2 would be processed for distribution to local communities. The criteria for ending Phase 2 will include either no large bodied fish have been captured for 48 hours when all available nets are used in a lake or Phase 2 effort has achieved 99% biomass removal based on the Phase 1 biomass estimate. Accompanying each Golder crew will be a local Aboriginal fisher staffed by Khione Resources Limited that will assist with fishing and processing of fish. On each shift, it is expected that two experienced fishers and two more junior fishers would be available to support the program. This approach provides additional benefits of having opportunities of knowledge transfer to younger members of the communities from more experienced workers. A final report will be generated for submission to Department of Fisheries and Oceans at the end of the Program. The fieldwork for this study will be conducted from June 25, 2017 to October 31, 2017.