(KLZA)--  The state has issued a health alert for Harmful Algal Blooms (HAB), also known as toxic blue-green algae, at Iron Horse Trail Lake (Wildlife Management Area) in Pawnee County.

Maskenthine Reservoir in Stanton County and Willow Creek Reservoir in Pierce County are still on health alert.

Samples taken earlier this week at the lakes on alert measure 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.