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Health alert for blue-green algae bloom in Lake Weir rescinded

By Florida Department of Health in Marion County

May 27, 2021


OCALA, Fla.—The health alert issued on May 17 regarding a blue-green algae bloom in Lake Weir has been rescinded. Water samples taken this week at the site of the previously reported algal bloom no longer show the presence of blue-green algae toxins. Lake visitors can resume their normal water activities.

The Florida Department of Health in Marion County had issued the health alert for the presence of Cylindrospermopsis raciborskii and Botryococcus braunii toxins in surface water. These toxins are related to the presence of blue-green algae. The impacted waterbody was Lake Weir with a main public access point along the north shore.

Blue-green algae (also known as cyanobacteria) can grow in Florida’s fresh waterbodies. Large concentrations of these algae, called blooms, can change the water’s color to blue, green, brown, orange, or red. Blue-green algae can grow rapidly and sometimes form a foamy surface scum and an unpleasant odor.

Some environmental factors that contribute to blue-green algae blooms are sunny days, warm water temperatures, still water conditions and excess nutrients. Blooms can appear year-round but are more frequent in summer and fall. Many types of blue-green algae can produce toxins.

What do I do if I see an algal bloom?

The Florida Department of Environmental Protection collects and analyzes algal bloom samples. To report a bloom to DEP, call the toll-free hotline at 855-305-3903 or submit a report online.For more information on algal blooms, visit