| Abstract/Description or Keywords |
Galena Ltd was retained by the Slocan Lake Stewardship Society (SLSS) to conduct the first part of a trendmonitoring water quality program on Slocan Lake as well as to provide recommendations for future sampling. The study was conducted in August, September and November of 2010. The 2010 program consisted of two components: an offshore component conducted monthly, and a nearshore component conducted during a 5-week period. The offshore study analyzed water samples for five general water quality parameters (temperature, dissolved oxygen, conductivity, pH and total dissolved solids), five nutrients (nitrate as N, nitrite as N, total nitrogen, total phosphorus and chlorophyll-a, 29 total metals and zooplankton. Seven sites were sampled for total coliform analysis during the nearshore study which, since it involved bacteriological sampling, had to be completed within a 5-week period of the summer season. Comparison, where possible, with the 2000–2001 (Pieters et al. 2006) and the 2008 (Galena 2008) surveys indicated little variability between those and the 2010 results. The 2000-2001 limnological survey was conducted primarily because the relatively pristine condition of the lake made it a good control for comparison purposes with the fertilization experiments on nearby Arrow Lakes and Kootenay Lake. Results from the 2008 baseline lake survey confirmed that Slocan Lake has remained oligotrophic and relatively pristine. The present 2010 trend-monitoring study will serve to assess long-term changes in water quality and will provide a basis for statistical identification of the possible causes of measured conditions or identified trends. Total coliforms were found at each of the seven sampling sites. Of all the sites, Slocan and Hills had the most total coliforms. Detection limits were sufficiently low to compare concentration results with the BC Water Quality Guidelines (BCWQG). General parameters, nutrients, and 28 of the 29 total metals met the BCWQG. Of all the metals, cadmium concentrations did not meet the Guidelines for the two primary uses of Slocan Lake, aquatic life and recreation. The present report describes the results of this study. Zooplankton density and biomass were measured at a 40m depth at sites 1, 2 and 3. Two species of copepods and three species of cladocerans were found during the sampling. Copepods were the most abundant zooplankton at each sampling station. Compared to the 2000-2001 study, there was a decrease in total zooplankton biomass and biomass of other cladocerans in 2010. |
