Algae bloom isn't cyanobacteria, DEP says of Carteria cordiformis in St. Lucie River
Tyler TreadwayRIO — A bloom reported at Outboards Only, a marina on the St. Lucie River that was choked with toxic blue-green algae in 2016, is a type of green algae that doesn't produce toxins, according to the Florida Department of Environmental Protection.
The bloom was identified as Carteria cordiformis late last week after a July 17 inspection.
It is a true algae found all over the world, whereas blue-green algae is actually a cyanobacteria, a naturally occurring microscopic bacteria that, like plants, use photosynthesis to produce food from nutrients and sunlight.
"I am not aware of any toxins that (Carteria cordiformis) produces," said Ed Phlips, a professor and algae expert in the Fisheries and Aquatic Sciences Program at the University of Florida.
For example, the algae does not produce microcystin, the cyanobacterial toxin often found in blue-green algae blooms.
"As long as it's not that toxic, dead-smelling stuff, I'm OK with it," said Outboards Only owner Phil Norman.
More: Everything you want to know about blue-green algae
Outboards Only marina
The green algae bloom has reappeared a few times since it first was reported in the marina's boat basin a week ago, Norman said, each time smaller than the time before.
In the initial sighting, the facility's boat basin "was covered with neon green at dead low tide," said Dave Schwartz, a marina worker. "You could see clouds of it coming in from the river. You could also see fish gulping for air, a couple of mullet and what looked like a black drum."
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The distinction between green algae and blue-green algae is an important one.
Blue-green algae has been reported in Lake Okeechobee for most of the summer, and typically the St. Lucie River doesn't get blooms unless they are released into the river from the lake.
More: Tests show highly toxic blooms in St. Lucie during 2016 discharges
During high-volume discharges in summer 2016, thick mats of foul-smelling blue-green algae clogged the Outboards Only boat basin.
The bloom contained the toxin microcystin at a rate of 14,000 parts per billion.
The federal Environmental Protection Agency considers levels above 8 parts per billion to be hazardous in recreational contact.
More: Scientists agree Lake O discharges cause St. Lucie River's algae blooms
More:Corps stops Lake O discharges to St. Lucie, cuts flow to Caloosahatchee
A Stuart company, Ecosphere Technologies, cleaned the bloom out of the boat basin with a weeklong process that included chopping up the algae, hitting it with electricity and high-frequency sound waves and pumping it full of ozone.