LINCOLN, Neb. -- The Department of Health and Human Services (DHHS) has issued a health alert for three lakes in Nebraska.

The state issued a health alert for Harmful Algal Blooms (HAB), also known as toxic blue-green algae, at Maple Creek Recreation Area Lake in Colfax County, Duck Creek Lake in Nemaha County, and Iron Horse Trail Lake (WMA) in Pawnee County.

The DHHS said that samples taken earlier in the week from these lakes measured above the threshold of 8 parts per billion (ppb) of total microcystin, which is a toxin released by certain strains of blue-green algae.

When a health alert is issued, signs are posted to advise the public to use caution, and designated swimming beaches are closed during the alert.

Recreational boating and fishing are permitted, but the public is advised to use caution and avoid exposure to the water, particularly avoiding any activity that could lead to swallowing the water. Do not let pets get in the water or drink from the lake. People can still use the public areas for camping, picnics and other outdoor activities.

Weekly sampling has been conducted at 53 public lakes since the first week of May. The lakes will continue to be monitored weekly through the end of September.