Base de données de recherche des TNO

Régions: Sahtu Settlement Area

étiquettes: aquatic ecosystems, biology, environmental monitoring, habitat assessment, benthic invertebrates, fisheries assessment

Objectif(s): To characterize biophysical conditions in Bosworth Creek in the area surrounding the lower Bosworth Creek bridge, both upstream and downstream from the location of a former weir.

Description du projet: WorleyParsons, on behalf of Imperial Oil, began a benthic invertebrate and fisheries assessment program for the portions of Bosworth Creek adjacent to the Imperial Oil operations in Norman Wells, NWT. The objective of the project is to characterize biophysical conditions in Bosworth Creek in the area surrounding the lower Bosworth Creek Bridge; both upstream and downstream from the location of a former weir. The weir was installed in the creek at the lower Bosworth Bridge in the 1960s, and was subsequently removed in 2005. This program will provide a qualitative and quantitative assessment of current creek conditions with respect to benthic and fisheries components, and supplement qualitative baseline data collected over the past 3 years by Sahtu Renewable Resources. Imperial Oil's Bosworth Creek monitoring program will consist of 1) benthic invertebrate sampling; 2) fish sampling; and 3) fish habitat assessment. The fisheries tasks will be undertaken in the spring and fall of each year, whereas the benthic sampling will be conducted annually. Benthic Invertebrate Sampling Benthic invertebrate samples will be collected at 3 to 4 locations on Bosworth Creek. The sampling stations will be located upstream of, at, and downstream of the original weir location (i.e., lower Bosworth Creek bridge). Three replicate benthic invertebrate samples will be collected at each sampling station using a Hess cylinder (250 um mesh). Samples will be preserved with 10% buffered formaldehyde and will then be sorted and identified. Benthic sampling will be conducted in general accordance with the Canadian Aquatic Biomonitoring Network (CABIN) program methods where appropriate, to allow for collaborative data sharing. Fish Inventory Inventories of fish populations will be conducted during the spring and fall open water seasons. The primary sampling techniques will include backpack electrofishing and minnow trapping. A range of morphometric measurements will be collected on all fish captured, including species identification, life history stage, gender, length, weight, and fish condition. Efforts will be made during all of the fish sampling work to minimize mortalities by regularly checking sampling gear and the use of proper handling techniques. Fish population information will be collected on standardized field sheets for ease of data compilation, assessment and reporting. Fish Habitat Assessment The stream habitat assessments will be conducted to assess the microhabitat features of Bosworth Creek. This assessment will examine individual channel habitat units (e.g., riffle, run, pool) in combination with water depth, velocity and substrate characteristics to provide a rating for each channel unit in relation to various fish life history stages (i.e., spawning, rearing, adult summer, migration and overwintering). Field methods have been developed by WorleyParsons fisheries biologists based on procedures adapted from published research (e.g., R.R.&L. 1992; Overton et al, 1997; Armantrout, 1998; and Arend, 1999). Habitat assessment data will be documented on standardized field sheets for ease of data compilation, assessment and reporting. As the project will build on work previously conducted by others (Sahtu Renewable Resources Board, Mackenzie Mountain School, Department of Fisheries and Oceans, Environment Canada, INAC, etc.) there is intent to share information collected with those parties/organizations. The researchers will provide a written or oral project updates / summary in 2011. The fieldwork for this study will be conducted from June 1, 2011 to September 15, 2011.