A comparison of all four lake groups in July

Jennifer L.K. Klang, Minnesota Pollution Control Agency

Minnesota is known for its many lakes. Our lakes differ in terms of size, shape, and depth and can also vary in quality and condition, ranging from exceptionally good (oligotrophic) to extremely poor (hypereutrophic). Secchi transparency, or clarity, is a quick and easy measurement of lake’s water quality. Secchi transparency provides an indirect measure of the amount of suspended material in the water, which in many Minnesota lakes is the amount of algae in the water. Secchi transparency can vary greatly among Minnesota’s lakes and tends to decrease as algal concentrations increase over the summer. The Minnesota Pollution Control Agency (MPCA) has developed a slide show that follows the change in Secchi transparency for four Minnesota lakes for one season (May – October). The lakes are from four different water quality classifications: oligotrophic to hypereutrophic. You can compare the four categories to each other, or you can watch the water clarity of each of the four lake groups as they change over the summer in response to increases or decreases in algae levels. There are some “underwater” shots as well. To visit the MPCA’s Secchi Transparency Slide Show, visit www.pca.state.mn.us/water/secchislideshow.html.

For more information contact: Johanna Schussler, Volunteer Monitoring Coordinator, johanna.schussler@pca.state.mn.us, 651-282-6411 – Twin Cities Metro, 800-657-3864 – Greater MN only

Posted in Lakes |