Portage Lake could possibly look like  this if chemical treatment is not continued. The photo actually shows Blueberry Lake located between Park Rapids and Menahga. Huge curly leaf mats formed when plants grew from the lake bottom and topped out at the water surface.  The water surface looked brown because plants were  starting to die after producing the turions or seeds. Turions break loose from the plants, floating to new locations, spreading the infestation.

This is  what a curly leaf mat looked like at the East end of Portage Lake in 2002 when  a survey determined about 48 acres of curly leaf  were present. However, by the time the first treatment was done in 2003, there were over 55 acres of curly leaf present.  It seemed like it was found everywhere, even in deeper water, but at least we  were able to treat 55 acres.  If you are a new resident here  and are not familiar with curly leaf pondweed, an INVASIVE SPECIES, the photos below show the plant, (with wavy,  finely toothed leaves, alternate leaf arrangement), its turions or seeds, and what it looks  like in the water. Curly leaf crowds out native vegetation, impedes navigation, fishing and water sports. Phosphorus  is also released into the water and sediment when the plants die.