NWT RESEARCH DATABASE

Regions: Sahtu Settlement Area

Tags: biology, fisheries assessment, lake trout

Objective(s): The objectives of this study are to: 1) gather baseline data on size and age structure, fecundity (egg number per female), growth and mortality of Dease, Smith, McVicar, McTavish, Keith arm lake trout. A different arm will be sampled each year over a 5 year time period. 2) To determine if lake trout are genetically distinct between basins. 3) To determine the extent of movements (if any) by lake trout in Great Bear Lake by using molecular genetics.

Project Description: The objectives of this study are to: 1) gather baseline data on size and age structure, fecundity (egg number per female), growth and mortality of Dease, Smith, McVicar, McTavish, Keith arm lake trout. A different arm will be sampled each year over a 5 year time period. 2) To determine if lake trout are genetically distinct between basins. 3) To determine the extent of movements (if any) by lake trout in Great Bear Lake by using molecular genetics. Methods: fish will be caught using angling or 5.5” and multi-mesh standard gang gillnets set in Smith Arm. Location data such as position (determined by GPS), time of year, time of day, net depth, water temperature, weather and other environmental conditions will be recorded for each set. To determine the catch-per-unit effort the net type, set time, lift time and soak time will be recorded. The fork length, round weight, gonad weight, egg number per female, sex and maturity stage, structures for determining the age and stomach contents of each fish will be taken. Sub-sampling of the carcasses for contaminants (mercury and radium) may also be done. Local field sampling technicians chosen by the Deline RRC will be trained to assist in the field component of the research. The study will involve the collection of biological data to determine age and size structure, growth, mortality, and fecundity of the lake trout population(s) of interest. The data will be used to assess the impact of changes in fishing policy by the Sahtu Renewable Resources Board, the community of Deline and the lodges on the lake. Trout movements and stock structure will be determined through molecular genetic techniques. Collection of tissues samples for these analyses are being carried out in conjunction with the sampling for the above described biological data. A summary report will be completed after the field season in 2007 and shared with the community through the Deline RRC. A detailed report and oral presentation will be supplied at the SRRB annual meeting and the Deline RRC. Fieldwork will be conducted from July 25 to August 05, 2007 on Great Bear Lake near the town of Deline.