The Florida Department of Health flagged three areas in the C-51 canal Monday with an alert after the waters tested positive for microcystin toxins.
A reading double what is considered harmful to human health was found upstream of Spillway Park, a popular fishing spot between Lake Worth Beach and West Palm Beach where water from the C-51 empties into the Lake Worth Lagoon.
The other two areas were in the C-51 canal near the bridge at Southern Boulevard and Military Trail, and near the bridge at Forest Hill Boulevard and I-95.
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Microcystin is a toxin created by the microcystis cyanobacteria, also called blue-green algae.
People are advised not to drink, swim or use personal watercraft in areas where there is a visible blue-green algae bloom, which can appear as stringy green tendrils in the water or thick cake-like mats.
The advisory also notes to keep pets away from the areas testing positive for microcystin and wash skin and clothing that comes into contact with an algae bloom or “discolored or stinky water.”
At Spillway Park, where multiple signs warned of algae and instructed that fish caught should have the filets rinsed with freshwater, the level of microcystin was 16 parts per billion (ppb) when the Environmental Protection Agency considers levels of 8 ppb or higher harmful to human health.
The water at Southern and Military tested at 2 ppb, while the water at Forest Hill and 95 was .36 ppb.
“Right now it’s not terrible, but, really, anything above zero is bad,” said Lake Worth Waterkeeper Reinaldo Diaz. “There is a little bit of an ‘oh crap’ moment happening where we know the conditions are ripe for blooms all around.”
Longer summer days, heat and nutrients washed into waterways during the rainy seasons are all ingredients for a blue-green algae bloom.
Ed O’Hara, an Ocala resident staying in Palm Beach County for the summer, was fishing for snook at the park with his sons Monday afternoon.
But he had no plans to eat anything they caught.
“We’re just doing catch and release,” he said. “I haven’t seen any of that green stuff yet and we’ve been fishing all over the place.”
But blue-green algae has been popping up in multiple Palm Beach County waterways. When the toxin levels are high, it has triggered the closure of gates that fill canals with Lake Okeechobee water and the shutdown of a feed from Lake O into Grassy Waters Preserve. Grassy Waters is the main source of water for West Palm Beach, Palm Beach and South Palm Beach.
The blooms can be fleeting. The water samples that triggered Monday’s release were taken June 2. There was no bloom visible at Spillway Park on Monday.
Microcystin toxins can cause serious health problems including liver failure in people and animals who swim in or drink tainted water.
Rashes, respiratory problems and nausea also are linked to the microcystin toxin.
Kmiller@pbpost.com
@Kmillerweather