NWT RESEARCH DATABASE

Regions: Sahtu Settlement Area

Tags: contaminants, ecological indicators, fish, benthic invertebrates, fish health, taxonomy, hydrocarbon seepage

Project Description: This study is designed to investigate various measures of small fish health at a number of locations along the Mackenzie River. The researchers want to find out if small fish health is different near oil seepages and the islands at Norman Wells than in other parts of the river. Also, the researchers will investigate fish and benthic invertebrate abundance and species composition at selected stream crossings of the proposed Mackenzie Gas Pipeline. In order to investigate measures of small fish health, 10 fish (forage fish size, <15cm) of each of 3-5 species will be collected from approximately 10 sites on the Mackenzie River, in the Fort Good Hope area. The researchers will not choose actual sampling sites until they are in the field, and have had a chance to investigate the river with community residents. Probable target species include spottail shiner, emerald shiner, longnose sucker, white sucker, trout-perch, ninespine stickleback, spoonhead sculpin, burbot, and cisco. All fish will be captured using a seine net, or by electroshocking (backpack). Transportation to sampling sites will be via boat. Researchers will also sample approximately 6 tributaries that will be affected by the proposed Mackenzie Gas Pipeline route in the Sahtu Settlement Area. On each tributary, they will sample 3 locations: upstream of proposed stream crossing, downstream of the proposed stream crossing, and at the tributary mouth. At each sampling location, the team will conduct an investigation of the fish community. This will be done by closing off a 100 m reach using seine nets and then by electroshocking the reach in three passes. Researchers will determine the species, length, and weight of the captured fish and then release them. Any fish killed during shocking will be kept for further laboratory analyses (stable isotope, ageing, etc.). At each location the team will also study the aquatic invertebrate community. This will be done by collecting three samples using a quantitative net sampler similar to a Surber sampler. Captured invertebrates will be preserved on site. At each sampling location they will also collect a water and sediment sample. Transportation to these sampling sites will be by helicopter. The research team will hire one or two local guides and will rent a boat locally. Affected communities will be kept informed of the progress of the studies. The study will be conducted at various sites along the Mackenzie River, near Fort Good Hope, and at six tributaries of the Mackenzie River in the Sahtu Settlement Area. The researchers will work out of Fort Good Hope and Norman Wells. The research will be conducted from August 1 to August 31, 2005.