Published: Oct 11, 2013 1:57 PM EDT

JACKSONVILLE, Fla. (AP) - An environmental group says water samples from an algae bloom in a northeast Florida river show toxin levels up to 100 times higher than what's considered safe by the World Health Organization.
    
The St. Johns Riverkeeper is warning people to stay away from the St. Johns River until the bloom dissipates.
    
The Florida Times-Union (http://bit.ly/1bLWu4U ) reports that Riverkeeper Lisa Rinaman outlined what she called "alarming levels" of microcystin algae toxin to the Jacksonville Waterways Commission this week.
    
Large algae blooms are deadly for fish, marine mammals, sea turtles and other sea life. The toxins also can become airborne and cause breathing problems for people with asthma or other respiratory diseases.
    
A  St. Johns River Water Management District spokeswoman says the agency tracked algae blooms this summer without finding similar readings.

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