What do septic tanks have to do with a massive seaweed bloom?

Researcher: ‘It’s like Jaws. You got to cut the food supply off.’

What do septic tanks have to do with a massive seaweed bloom?
What do septic tanks have to do with a massive seaweed bloom?

ORLANDO, Fla. – Researchers blame rising temperatures, fertilizer runoff and increasing nitrogen levels from old septic tanks for a growing bloom of seaweed that made its way to Central Florida.

The piles of seaweed washed up on the shores of Brevard, Volusia and Flagler counties in May, and it was so thick in some places that shovels were no match for it.

“In your mind, you have this pristine beach that you see in all the pictures of Florida, and then you see this, and it’s like, ‘That’s not what I expected,’” said Andy George, who was visiting Cocoa Beach with his wife, Melanie.

“The seaweed problem we’re talking about is this brown floating seaweed – sargassum,” Dr. Brian LaPointe said.

LaPointe is a research professor at Florida Atlantic University, and he said he has been studying sargassum since the 1980s.

He said what he has discovered over the past 10 years, however, is becoming more and more concerning.

According to research conducted by LaPointe and some of his colleagues, a floating bloom of seaweed started growing near the mouth of the Amazon River in the Atlantic Ocean in 2011 and it hasn’t stopped.

Research from Florida Atlantic University showed a Sargassum bloom develop in 2011 and grow to its largest size in 2018. (Copyright 2021 by WKMG ClickOrlando - All rights reserved.)

In 2014, he said it stretched into the Caribbean Sea.

In 2018, he said it reached its largest size on record, reaching into the Gulf of Mexico and up both coasts of Florida.

Research from Florida Atlantic University showed a Sargassum bloom develop in 2011 and grow to its largest size in 2018. (Copyright 2021 by WKMG ClickOrlando - All rights reserved.)

“Somehow, things have changed,” he said. “Again, we’re talking climate change and other aspects of global change. Not just climate change (is happening), but human population growth on top of climate change.”

He pointed to the increase in nitrogen being released into the water, which he said is feeding the floating bloom.

“If you look around the state, we have millions of septic tanks with no nitrogen removal. We have ocean outfalls in Miami-Dade and Broward County, pumping millions of gallons every day of nutrient-rich sewage effluent out into the coastal waters,” he said.

How can it be stopped?

“Well, it’s like ‘Jaws.’ You got to cut the food supply off,” he said.

“This has been a priority for all of us,” said State Rep. Rene Palcencia, R-District 50.

Placencia serves residents in part of Brevard County, and he said state projects were already underway to help stop nitrogen leeching into the soil from septic tanks.

But with 2.6 million septic tanks in Florida, it may not be a quick fix.

“It’s expensive,” he said. “We slowly are shifting and converting our septic systems that are in close proximity to our very fragile waterways, whether it’s a river, an aquifer system, or an intercostal waterway, like the Indian River Lagoon, and switching it to city sewer.”

Other representatives in Brevard, Volusia and Flagler counties shared Placencia’s concern, and they also said controlling the nitrogen outflow is near the top of their to-do list.

State Rep. Jason Brodeur, R-District 9, said the legislature has made “huge strides” by raising standards for wastewater treatment, including on-site septic tanks.

“It’s important to note that the sargassum that washes up on Florida beaches is believed to be caused by nitrogen enrichment from sources as far away as the Amazon River and West Africa,” said State Sen. Jason Brodeur. “While these blooms are likely to continue despite our efforts here in Florida, I’m committed to the support and growth of programs like septic-to-sewer conversion to help lower the nutrient load in our waters.”

“Senate Bill 2512, now law, directs dedicated revenues from documentary stamp tax dollars into the Water Protection and Sustainability Program Trust Fund to support the Wastewater Grant Program established by SB 712,” said State Sen. Debbie Mayfield, R-District 17. “These significant investments in upgrading the state’s wastewater infrastructure will prevent nutrients from entering our waterways, reducing the food available for harmful algae and plant blooms.”

“Again, if we don’t cut off the nutrient supply that is creating this uptick in this trend, then they’re going to continue to worsen and worsen,” LaPointe said.

LaPointe said he expects more of the sargassum bloom to reach Florida shores this summer.


About the Author:

Erik Sandoval joined the News 6 team as a reporter in May 2013 and became an Investigator in 2020. During his time at News 6, Erik has covered several major stories, including the 2016 Presidential campaign. He was also one of the first reporters live on the air at the Pulse Nightclub shooting.