Lyngbya Treatment Underway at Mountain Island & Lakes Norman & Wylie

Published on April 25, 2025

Pollen and weeds along the shore of Mountain Island Lake

If you've spent time around Lake Norman, Mountain Island Lake, or Lake Wylie recently, you might’ve noticed dark, musty-smelling mats floating near the shoreline. That’s not harmless debris—it’s Lyngbya, a type of cyanobacteria (also known as Microseria wollei) that’s been spreading rapidly across southern reservoirs. Unlike typical algae blooms, Lyngbya sticks around year-round, forming thick, fuzzy mats in warm, nutrient-rich water that can clog boat motors, degrade water quality, and ruin the lake experience for everyone.

The good news? A major effort is now underway to fight back. From now through September, the Catawba-Wateree Water Management Group, in partnership with local governments, marine commissions, N.C. State University, and Duke Energy, is launching a coordinated treatment plan across all three lakes. A total of 60 acres will be treated this season, using EPA-approved algaecides applied by Aqua Services, Inc. While you may see airboats dispersing a bright blue liquid near the shoreline, rest assured—it’s safe for people, pets, and plants.

Learn more about Mountain Island Lake Lyngbya Management