| Abstract |
For water samples collected during the 1980 intensive surveillance of Lake Huron, a number of conclusions can be drawn. Total silver, chromium, copper, manganese, iron, and arsenic were highest in the epilimnion. The horizontal variation of total metal concentrations from month to month were quite variable. Iron was always highest in southern Lake Huron and copper and manganese were highest in the North Carolina. Total metals exhibited some variation with time. In general, highest total metal concentrations occurred in April and May for most metals. Predicting trace metal trends is difficult. Improvements in instrumentation and methodology have lowered detection limits and the amount of sample contamination. A number of metals appear to be decreasing in concentration. These include dissolved arsenic, total cadmium, dissolved cadmium, dissolved copper, total lead, dissolved lead, total nickel, dissolved nickel, total zinc, and dissolved zinc. Total cobalt and total vanadium concentrations appear to have increased. |
