Blue-green algae: What you need to know
If you lived in or visited Southwest Florida in 2018, you may be familiar with the term “blue-green algae.”
Those who experienced the blue-green algae bloom may recall the sight of green gunk in the water, the smell, or the effect it had on businesses. The bloom was so problematic, Governor Rick Scott declared an emergency on the blue-green algae crisis.
Dr. Mike Parsons has quickly become one of the faces of our water quality concerns. He is a professor of The Water School at Florida Gulf Coast University, Director of Vester Field Station, and a member of the governor-appointed Blue-Green Algae Task Force.
We talked to him about what blue-green algae is and what the concerns are.
Although its name may not immediately suggest it, Dr. Parsons said blue-green algae is actually a bacteria called “cyanobacteria.” Despite being related to bacteria, cyanobacteria actually photosynthesize like plants and algae.
Cyanobacteria isn’t exclusive to canals. Parsons said it can be found in freshwater, marine environments, and even on land.
Parsons said cyanobacteria, similar to red tide, is always around even if it’s not producing thick mats, odors, or toxins.
But how does blue-green algae bloom in the first place? Parsons said there are a number of contributing factors. “So for the blue-green algae, definitely nutrient enrichment. The second part is they like stagnant, warm water. So if you’re just holding water, letting it warm up when we get into spring and summertime, not really aerating it so on and so forth, you’re pretty much guaranteed to get a cyanobacteria bloom,” Parsons said.
Nutrients can come from sources including fertilizer, septic tanks, and pastureland.
“When you look at the cyanobacteria, there are, you know, let’s say a thousand species and maybe out of those thousand species, maybe only 50 or 100 will actually bloom and discolor the water and make thick mats and things like that,” Parsons said.
He said a smaller number of those types of cyanobacteria produce toxins, “So it’s actually a pretty rare phenomenon when you get a cyanobacteria that both blooms and forms toxins.” Parsons believes that’s why we’re paying such close attention to blue-green algae now.
The concerns over blue-green algae go beyond sight and smell.
One type of cyanobacteria garnering attention is microcystins, because, according to the U.S. Environmental Protection Agency, it almost always produces toxins. According to EPA, “Microcystins primarily affect the liver (hepatotoxin), but can also affect the kidney and reproductive system.”
The Florida Department of Health said adults, children, and pets need to avoid the water when blue-green algae is present. The agency said, “It is best not to come in to contact with water in areas where
you see foam, scum, or mats of algae on the water.” Furthermore, blue-green algae toxins can cause rashes or nausea, or in some cases of high exposure, it can affect the liver or nervous system.
The U.S. Army Corps of Engineers releases water from Lake Okeechobee for different reasons: The health of the lake, flood control, and the health of surrounding estuaries. When that water is released from the lake to the Caloosahatchee River in Southwest Florida, it can contain algal blooms. “We can’t aerate the whole Lake Okeechobee. So that’s part of the problem when we get the blooms on Lake Okeechobee,” Parsons said.
While there isn’t one solution to get rid of harmful algal blooms, a raised awareness has brought researchers, lawmakers, and communities together working towards solutions