Abstract:
A limnological study was conducted on the 135 ha Wyandotte County Lake, located in the County Park at 9lst Street and Leavenworth Road in Kansas City, Kansas. Water quality data were established by determining physicochemical parameters and by sampling the benthic macroinvertebrate community from 1 June 1977 and 18 November 1977 and from 30 March 1978 to 5 May 1978. Seven stations were established over the lake at depths ranging from one to 15 meters. A total of 28 taxa consisting of 11,897 individuals of benthic macroinvertebrates was collected. Eight taxa of zooplankton were collected. Individual species diversity indices (d) for benthic macroinvertebrates were calculated for each station by depth and mean monthly variations in d were calculated with all depths combined. Annual d values ranged from 1.0 to 1.9, with an annual mean of 1.4, indicating moderate stress in the aquatic system. Coliform counts averaged 62/100 mI. Thermal conditions were in line with expected seasonal variations for a moderately-deep temperate lake with a spring and fall holomixis and a well-established direct stratification in mid-summer. Oxygen was present in the summer at concentrations from 2.5 to 7.7 mg/liter and at depths from 8 to 15 meters, oxygen was likely to be depleted. Secchi disc transparency varied from 0.53 to 2.50 meters. The mean lake euphotic zone was 4.66 meters. Nitrate was high, ranging from.
6.0 to 17.0 mg/liter, with an annual mean of 11.41 mg/1iter. Phosphate ranged closer to normal, with a minimum of 0.06 and a maximum of 0.23 mg/liter. Mean annual phosphate was 0.16 mg/liter. The nitrate : phosphate ratio was 70 : 1, suggesting an important outside source of nitrate. Ammonia nitrogen had a yearly mean of 0.73 mg/liter, within the limits for unpolluted water. Sulfate was low, ranging from 12.0 to 22.0 mg/liter, with an annual mean to six meters of 17.8 mg/liter. Nitrate was slightly above unpolluted standards, ranging from 0.001 to 0.260 mg/liter, with an annual mean of 0.026 mg/liter. Trace metals were measured at the beginning and end of the study. Copper ranged from 1.09 to 1.95 mg/1iter. Iron ranged from 0.06 to 0.10 mg/liter. Wyandotte County Lake appeared to be a moderately
enriched system.
