On the ground and in the water dozens of people came together demanding action, Saturday afternoon.
"Our river is basically on life support," one man said.
People who live in Martin County are continuing to see the worrisome sight of potentially toxic algae across the St. Lucie Estuary.
"It's been happening for decades and it's getting worse and worse every year," a protestor said.
In the summer of 2016, freshwater discharges from Lake Okeechobee were one cause of widespread toxic algae blooms in the estuary, leaving behind streaks of green and clumps of Algae.
"We need to do something now send the water south and put the water where it needs to be not in our rivers killing our ecosystem," Samantha Miller said.
For many at the Roosevelt Bridge in Stuart this wasn't their first protest on this topic and they say until the water is clean it won't be their last.
"We're going to scream louder, and we're never giving up," a protestor said.