— -- The slimy, smelly toxic algae overtaking some waterways in southern Florida is so widespread it can now be seen from space.
NASA's Landsat 8 satellite snapped a photo on July 2 showing a blue-green algae bloom in Lake Okeechobee.
While algae blooms are a common summer occurrence, they've been especially problematic this year in many southern Florida waterways.
Health risks associated with blue-green algae occur when "people or animals are exposed to toxins that are sometimes produced by certain kinds of these organisms," according to the Florida Department of Health. "Exposure can happen through unintentionally swallowing lake or river water, breathing water spray or coming into direct contact with the blooms. At high levels, these can affect the gastrointestinal tract, liver, nervous system, and skin."
The department of health added that "it is recommended that people avoid contact with all algal blooms," and that "[c]hildren and pets are especially vulnerable, so keeping them away from the water during a bloom is especially important."
ABC News' Avianne Tan contributed to this report.