CENTRAL LAKE, Mich. A northern Michigan lake thats famous for its turquoise waters is facing an outbreak of brown algae thats left its sandy bottom covered with mushy, squishy mats. Rick Welsh, a part-time lakeshore resident, said the brown algae was first noticed about a decade ago, but now the golden-brown algae grows in thick mats and sticks to the otherwise sugar-sand bottom of the lake in Antrim Countys Torch Lake, according to the Traverse City Record-Eagle. Its oozy, yucky and mucky, Welsh said. It easily comes up when disturbed.Welsh, a member for the Torch Lake Protection Alliance, said that there are investigations into the algae with results due in the fall. Officials with the Michigan Department of Environment, Great Lakes and Energy, have said it appears to be a non-harmful form of algae.