Base de données de recherche des TNO

étiquettes: physical sciences, mining, water quality, geology, hydrology, sediment quality, environmental baseline

Objectif(s): To further characterize the baseline water and sediment quality and aquatic communities at specific lakes within the Thor Lake area and Avalon's Thor Lake Rare Earth Elements Project footprint; and to collect additional data to support the fish-bearing designations for lakes within the Ring group of lakes.

Description du projet: The objective of the 2011 Aquatics program is to continue baseline data collection to further characterize the baseline water and sediment quality and aquatic communities at specific lakes within the Thor Lake area and Avalon's Thor Lake Rare Earth Elements Project footprint. The 2011 Fisheries program will focus on the lakes directly affected by and immediately downstream of the proposed Tailings Management Facility. The objective of the 2011 Fisheries program is to collect additional data to support the fish-bearing designations for lakes within the Ring group of lakes (Ring, Ball, Buck, Drizzle and Murky). Water, sediment and aquatic organisms will be collected at up to 8 stations (7 lakes) within the Thor Lake area. Most stations will be accessed by ATV and/or boat in summer and fall, and snowmobile in winter. Several stations will require the use of helictoper for access. A multi-parameter meter will be used to obtain depth profiles of temperature, oxygen, pH and conductivity in the field. Water samples will be collected at one depth at each sampling station, depending on lake characteristics. Water samples will be analysed for routine parameters (e.g. turbidity, total suspended and total dissolved solids, alkalinity, major ions), nutrients, total and dissolved metals, dissolved organic carbon and radionuclides (lead-210, radium-226, radium-228, thorium-228, thorium-230 & thorium-232). Sediment samples will be collected from the lake bottom at three locations around the sample stations at Drizzle and Murky lakes. Sediment samples will be analysed for total metals, total organic carbon, total phosphorus, total kjeldahl nitrogen, organochlorines, radionuclides, PCB congeners, and particle size distribution. Phytoplankton samples will be collected during spring and summer at all sample stations except Ring and Buck; species composition, abundance, chlorophyll a and phaeopigment levels will be assessed. Zooplankton samples will be collected concurrently with phytoplankton samples with a standard zooplankton net in a horizontal or vertical tow, depending on lake depth. Samples will be examined for species composition and abundance. Benthic invertebrate samples will be collected with an Ekman grab at Drizzle and Murky lakes. Grabs will be sieved in the field and specimens will be collected and preserved; samples will be examined for species composition and abundance. Gill nets with varying mesh sizes will be used for fish sampling in order to target the full range of fish species and sizes. Gill nets will be set overnight. Stantec currently has two years of fisheries data from the Ring system and most lakes in the system are considered non-fish bearing. However, if any fish are caught, they will be enumerated, identified to species, and measured for length and weight. Local field assistants will be hired to participate in the baseline field studies throughout 2011. Information including data and analysis on surface water quality and fisheries in and around Thor Lake will be available to locals and communities for review. The information may provide locals with a more thorough scientific overview of the local surface water quality and fish communities which can be used for various purposes (e.g., land use planning, economic development). Results of Stantec's 2008-2010 baseline studies at Thor Lake were communicated to members of affected communities in a baseline research update session in early 2011. Results from Det'on Cho Stantec's 2011 baseline program will be provided to affected communities through Avalon as it proceeds through the regulatory, environment assessment, and licensing processes. The fieldwork for this study will be conducted from July 15, 2011 to October 4, 2011.