Lake Nokomis beaches under a blue-green algae advisory

MINNEAPOLIS (FOX 9) - Elevated levels of cyanobacteria, also known as blue-green algae, are prompting health advisories for both beaches at Lake Nokomis. 

The Minneapolis Park and Recreation Board (MPRB) said samples taken from the main beach showed levels of Microcystin, a toxin group that is produced by cyanobacteria, that exceeded its standards for closure.

While toxin levels were below standards at the 50th Street beach, officials say lake conditions can quickly change based on weather and wind direction. 

Blue-green algae at Lake Nokomis

Big picture view:

Minneapolis park officials say that hot weather, sunny skies and high water temperatures above 75 degrees make ideal conditions for the growth of blue-green algae.

The Minnesota Pollution Control Agency said blue-green algae blooms can be harmful when they produce toxins that can make humans and animals sick, but most blooms are not harmful. 

However, beach-goers can't tell by looking at a bloom if it is harmful or not.

What you can do:

Anyone exposed to blue-green algae should shower and rinse immediately.

If you do choose to swim, be careful to not get any of the lake water in your mouth. 

Those who cook fish caught from the lake are advised to throw away the guts and clean the fillet with tap or bottled water. 

The MPRB said body contact with water in Lake Nokomis is not recommended for people or pets. 

Dig deeper:

The same advisory was in effect at the same lake last summer.  

More information on the harmful effects of blue-green algae can be found from the Minnesota Pollution Control Agency and the Minnesota Department of Health.