MADISON, Wis. -- The state Department of Health Services has a warning for boaters and others who may be out on lakes and ponds across Wisconsin this coming holiday weekend.

Department offcials are warning people to protect themselves from toxic blue-green algae. State Health Officer Dr. Seth Foldy said coming into contact with, or swallowing water with high levels of blue-green algae poses a health risk.

Foldy said people and pets should avoid swimming where the water looks like paint or pea soup.

Algae blooms can form thick, foul-smelling layers on the surface of water and can range in color from green and fluorescent blue to red.

Officials said swimmers should always shower with soap and water after being in lakes and rivers.