Last week’s blue-green algae watch for Marion County Lake was increased to a warning Thursday after tests indicated water might not be safe for humans, pets, or livestock to drink.

Although the lake remains open, Kansas Department of Health and Environment is urging visitors to avoid contact with lake water, especially in areas where algae blooms are present.

If lake water contacts skin, the area should be rinsed promptly with clean water, KDHE says.

The department advises that fish taken from the lake still may be eaten, provided they are rinsed with clean water and only the filet is consumed.

Pet owners should take care to prevent their animals from eating dried algae.

Blue-green algae, technically known as cyanobacteria, release toxins when they die. Some toxins cause only minor skin irritation, but some can be powerful neurotoxins.

The lake is checked weekly and its status is updated every Thursday. The lake has been subject to an algae warning or less serious watch all month.