NWT RESEARCH DATABASE

Regions: South Slave Region

Tags: fish, Transboundary, Slave River, biomonitoring, bioindicators

Objective(s): To collect additional samples for fish health and fish contaminant levels, and to track their status over time to assess ecosystem health and provide an indication of change or stress in the environment.

Project Description: This licence has been issued for the scientific research application No. 5961. The objectives of this project are to collect additional samples for fish health and fish contaminant levels, and to track their status over time to assess ecosystem health and provide an indication of change or stress in the environment. Monitoring will focus on the same species of fish that were investigated in past studies in the Slave River (burbot (Lota lota), lake whitefish (Coregonus clupeaformis), walleye (Sander vitreus), northern pike (Esox lucius)) as well as species included in Oil Sands Monitoring program (white sucker (Catostomus commersoni), longnose sucker (Catostomus catostomus), and trout-perch (Percopsis omiscomaycus)). Alternative small-bodied fish species may be considered if low numbers of trout-perch are collected, which includes emerald shiner (Notropis atherinoides) and spottail shiner (Notropis hudsonius). The timing and method of sampling fish will vary according to spawning seasons, community fishing practices, and historic sampling programs. Small-bodied fish : We will attempt to sample small-bodied fish monthly, beginning as early as mid-May at three sites near Ft. Smith (between the Rapids of the Drowned and below the mouth of the Salt River) and ending in September/October. Additionally, we will sample three sites near Ft. Resolution (within 25 km of Big Eddy) twice: once in early summer (June), and once in the fall (September). Summer sampling near Ft. Smith will be lead by FSMC. Spring and fall sampling near Ft. Smith and Ft. Resolution will be part of Transboundary monitoring implementation. Target species will be trout-perch, emerald shiner, and spottail shiner. The fish will be collected using boat electrofishing equipment and/or seining in partnership with community members in Ft. Smith and Ft. Resolution. The target will be 20 adult males and 20 adult females at each site during each sampling occasion. The lengths and weights, including organ weights, of these fish will be measured and tissues will be collected for contaminant analyses, ageing, stable isotopes, and liver enzyme activities. Large-bodied fish: FSMC will target walleye, captured from the Slave River between the Rapids of the Drowned and the Salt River during the spring spawning run. In the fall (September), large-bodied fish including walleye, northern pike, longnose sucker, goldeye, burbot and lake whitefish will be captured both near Ft. Smith (captured from the Slave River between the Rapids of the Drowned and the Salt River) and Ft. Resolution (between Slave River at Big Eddy, Slave River delta, and Great Slave Lake at Resolution Bay). The target will be 20 male and 20 female adults for each species during each sampling event. We are working in partnership with subsistence harvesters, where the method of capture will be with gillnet (4.25") and/or boat electrofishing by the FSMC at Ft. Smith. The lengths and weights, including organ weights, will be measured and tissues will be collected for contaminant analyses, ageing, stable isotopes, and liver enzyme activities. Bycatch will be sampled for these same parameters or used for subsistence. In the winter (December), 20 male and 20 female burbot will be targeted at these same locations near Ft. Smith and Ft. Resolution under-ice by angling, setlines, and/or gillnet. In addition to sampling fish, samples for water quality, sediment quality, and benthic invertebrates may also be collected in coordination with GNWT and CBM programs. Water quality samples will be collected following standard NWT water quality CBM protocols. Sediment quality samples will be collected using eckman and/or ponar surface sediment grabs. Benthic invertebrates would primarily be collected for stable isotope analysis to complement stable isotope analysis in fish. Benthic invertebrate collection methods may include kick-sweep method per Canadian Aquatic Biomonitoring Network (CABIN) in wadeable areas, eckman or ponar surface grab samples, or deployment of artificial substrate samplers (e.g., rock baskets or Hester Dendys). This application is for a multi-year permit. The overall design of the program is to follow an adaptive monitoring approach, such that if changes are detected, consecutive years of sampling is likely to be required to confirm results. However, if no changes are detected, less intensive fish monitoring may be recommended (e.g., sample all species every 3 years), though a subset of species may be sampled annually along with water quality and sediment quality based on direction from communities. Results reporting is conducted during various workshops, such as the annual Water Stewardship Strategy implementation workshop that takes place every fall, CIMP workshops, GNWT-ECC South Slave Region Wildlife Workshop, and community open houses or workshops in Ft. Smith and Ft. Resolution. In addition to in-person meetings, summary reports, posters, and bulletins will be prepared and distributed to share results. Technical and plain language reports detailing the findings of the monitoring program will be shared when completed. The fieldwork for this study will be conducted from: June 10 - December 31, 2024