NWT RESEARCH DATABASE

Regions: Dehcho Region, South Slave Region

Tags: contaminants, mercury, fish

Objective(s): To determine through which lakes are important as food sources in four Dehcho communities and which fish species are used for human food.

Project Description: The objectives of this project are: 1) to determine through which lakes are important as food sources in four Dehcho communities and which fish species are used for human food from these lakes; 2) to train community monitors to collect fish and other samples according to Environment Canada and Department of Fisheries and Oceans protocol; 3) to involve local school children in the studies by arranging in-the-field study camps or in-school presentations with the schools and the community recreational directors; 4) to update data on mercury levels in various species of fish that may have changed since previous studies in the 1990’s and more recent studies by providing Environment Canada with the required fish samples; 5) to assist scientists in their investigation of factors affecting increased mercury concentrations in predatory fish in the Dehcho and elsewhere in the Northwest Territories; and, 6) in the long-term; to contribute to the evidence data base which can be used in National and International negotiations and agreements to lower the levels of mercury and carbon dioxide pollution in the atmosphere. Each lake will be sampled one at a time throughout the winter fishing season (December- March). Crews will consist of a biologist and/ or technician and two local community monitors. Equipment and personnel will be hauled into the desired lakes via snowmobiles. The following is a step by step procedure of the methodology that will be used for this project. 1) Using traditional knowledge provided by community members and local monitors, net set locations will be determined so that the desired fish species can be caught using the least amount of effort. 2) Fish will be caught using multi paneled gill nets, with each panel consisting of a different mesh size. The gill nets will have three panels attached to make a gang, one panel consisting of 3.5 inch mesh, another of 4.5 inch mesh and one of 5.5 inch mesh. 3) Each morning 2 gangs will be set in predetermined locations underneath the ice. A chisel will be used to make a hole through the ice and a jigger will be used to pull the nets beneath the ice. 4) Nets will soak in the water for up to 24 hours before being checked and then reset either in the same location or elsewhere. 5) When nets are checked after 24 hours fish will be removed and counted according to fish species. These are the fish that are going to be biologically sampled at the base camp. After the desired amount of one fish species is caught anymore fish of that species will either be given to the community for subsistence or released alive. 6) Before fish freeze they will be biologically sampled for the following information: Length, weight, aging structure, sex, maturity and a tissue sample for mercury analysis. Sampling will occur in a heated canvas wall tent each day after the fish is caught. 7) Aging structures and tissue samples will be frozen and sent to Environment Canada for analysis. 8) Water quality measurements will be collected from net set location, and will include dissolved oxygen, conductivity, pH and temperature. 8) Each lake should be completed within one week. After the samples have been analyzed, results will summarized and reported back to the community. This project will include local involvement at every level, local community members will assist with collection of data and maintain camps. Local traditional knowledge will be utilized to determine what types of fish can be caught and where, as well as determining historical and present uses of the lakes. All community participants will be trained in collecting biological data from fish and the operation of any scientific instruments. There will also be opportunities for local youth to be involved in data collection, field work and any training. One of the objectives of this project is to develop a communication plan with the communities in relation to public health and food. In the meantime reporting will consist of meeting with the communities before data collection occurs and after results are produced. Results will be summarized and PowerPoint presentations will be made for each community, as well a project summary will be made for presentations at any other meetings. The fieldwork for this study will be conducted from June 1, 2016 to December 31, 2016.