Shoreline Survey Finds Increased Algal Growth

Nearly one in every five Lake Charlevoix shorefront properties have an algal growth, Cladophora, that indicates excess nutrients from fertilizers, septic tanks, stormwater runoff and treated sewage water, according to a new survey done last summer by staffers from the Tip of the Mitt Watershed Council.

The growth does not pose any immediate health threat to swimmers or boaters, but it is a sign of the difficulty we face in trying to preserve a pristine waterway and a natural food chain while residential development and other activity increases around the lake.

How the survey was done

Working out of kayaks a few feet from shore, the Watershed staffers found 288 properties of the 1,600 around the lake had growth ranging from a green shimmer on shoreline stones to dense matting that covered rocks in the splash zone. Sixty properties had heavy infestation, 114 had moderate growth and another 114 were rated light. A similar survey by Lake Charlevoix Association volunteers in 2000 found 259 properties with some level of Cladophora infestation. But because the methodology and the number of properties checked were somewhat different, it is not possible to make direct comparisons between that survey and the new one.

What Causes the Growth

The algae thrive on minerals washed into the lake from a variety of sources including lawn fertilizers, septic tanks, stormwater runoff and sewage plant effluent that has not been treated to a high enough level of purity. The Cladophora problem is evident on the shores of Lake Michigan and the other Great Lakes, and researchers have linked the phenomenon to higher water temperatures, lower lake levels and greater water clarity (thanks to industrious zebra mussels) that allow the algae to make effective use of the minerals from human activity. That inhibits the growth of other algae that have been the basis for the food chain that supports the historic variety of fish life.

What Can You Do?

Property owners can not safely get rid of the growth in any quick way because the minerals have already washed into the lake bottom. But they may be able to discover the source of the materials and reduce the amount of phosphorus-heavy lawn fertilizers they use or to repair any septic field leakage. Cutting off the algae's food supplement would reduce future growth. To help analyze your specific situation, you may wish to contact Kevin Cronk at Tip of the Mitt Watershed Council. Kevin is available, for a fee, to perform a study of your shoreline to help determine the cause of any problems and to suggest methods for improving the situation. To reach Kevin, you may use email, kevin@watershedcouncil.org or telephone, 231-347-1181. You may also contact the Lake Charlevoix Association Board at info@lca-mi.org if you would like to speak with a board member. More information regarding What Can You Do

Some Generalizations about the Results

In many cases, the survey found a single property with excess cladophora bordered by many properties with none, suggesting a single-source culprit. Near Boyne City, however, which has been wrestling with issues of proper sewage treatment, the survey found many contiguous properties with above average growth. Other concentrations were on the west side of the South Arm north of East Jordan, west of Advance and north of Young State Park in Horton Bay. Riparian owners should be aware of the fact that the make-up of the lake bottom of their property is a critical requirement for Cladophora growth. Because of this, you may not have growth even though there are minerals going to the lake. Even if algae growth is absent, please be vigilant about keeping nutrients out of the lake.

View the Survey Data- How Did Your Shorefront Rate?

Property owners who wish to know which property is theirs should look to the right of their name on the mailing label of their spring 2008 LCA newsletter. The four-digit number by your name can be matched up with the ID codes on the survey. This random coding system was designed to keep property ownership confidential. It is our hope that neighbors will share their numbers so that groups of owners in different localities around the lake will work together to address any problems. If you are a lakefront owner that does not have their ID code, you may contact LCA through info@lca-mi.org. Verifying your identity will be a requirement for receiving your ID code.

To find out more follow these links.

1. View all data from the 2007 survey. Have your code number ready. (excel file) (html file)
2. Overview of abbreviations and content for the data base.
3. Full Tip of the Mitt Watershed Council Report from their 2007 survey