Mowry, L. A. Humboldt State University, firstname.lastname@example.org
Brenneman, K. A. Humboldt State University, email@example.com
WATER QUALITY EVALUATION OF TWO HIGH-USE, FISH STOCKED ALPINE LAKES IN THE KLAMATH NATIONAL FOREST
Most alpine lakes in the Klamath National Forest are stocked to provide a char and salmonid recreational fishery. Fish introductions increase nutrient loads to lake systems by way of human impacts and fish wastes and die off. This study examined Taylor Lake and Kangaroo Lake in order to establish baseline water quality criteria for the use in the USDA, Forest Service fish stocking program. Dissolved oxygen (DO), pH, temperature, conductivity, Secchi depth, and selected nutrients were measured at open water, inflow, and outflow sites. In addition, fecal coliform and fecal streptococcus tests were performed. The water quality of Taylor Lake was determined to be normal for a freshwater system. However, temperature and DO profiles were not indicative of an oligotrophic alpine lake and showed a trend toward eutrophy. Mid lake site (8 m) DO levels ranged from 9.6 mg/l at the surface to 2.0 mg/l at lake bottom. The Secchi depth at this site was 6.5 m. Taylor Lake inflow site samples contained high phosphate concentrations, with the greatest value being 29.0 mg/l. Dissolved oxygen levels at Kangaroo Lake (30 m) ranged from 8.7 mg/l at the surface to 10.2 mg/l at its deepest, with greatest concentrations at 12.8 m of 13.7 mg/l. The Secchi depth was 10 m. Although profile results showed a typical orthograde curve in Kangaroo Lake, testing of the outflow, using the California Rapid Bioassessment Protocol, exhibited a moderate to severe impairment, indicating poor water quality of lake effluent. No detectable levels of fecal coliforms were found in Taylor Lake, but fecal streptococci were present in high concentrations, indicating that the lake is receiving fecal material from an animal source. Both fecal streptococci and fecal coliforms were found in high concentrations in Kangaroo Lake indicative of the presence of human waste contamination. Information obtained by these two studies suggest that the result of activities surrounding fish stocking appears to have a negative effect on the water quality of alpine lakes located in the Klamath National Forest region.
Day: Wednesday, Feb. 3
Location: Sweeney Center