The effect of taconite tailings on primary productivity in the Silver Bay area of Western Lake Superior

Considerable concern has arisen over the possibility that the discharge of taconite tailings into Lake Superior could affect algal primary productivity. In 1972, primary productivity studies utilizing the carbon-14 technique were run in the Silver Bay area. Samples were collected and analyzed on a weekly basis for a three month period that included a five week plant shutdown period. Resultant productivity data indicate that there is no apparent relationship between primary productivity and the discharge of taconite tailings. Productivity trends in the Silver Bay area tend to conform to the known seasonal behavior of phytoplankton in western Lake Superior.