Brown patches along Gulf beaches are likely algae, scientist says

A state scientist says patches of brownish water turning up on Gulf of Mexico beaches from time to time this summer likely isn't sewage or red tide, but rather a form of algae that comes and goes with the tide. 

Florida Wildlife Conservation Commission research scientist Celia Villac said she’s seen and the agency has received other reports of “red drift algae” along the beaches. 

“These can be a mix of different red and brown seaweeds, some of them very fine filaments,” Villac said. “These patches can move around quite a bit with the surf and winds.” 

The algae forms, and as soon as the nutrients are used up, it decays and sinks to the sea floor. But a storm can stir it back to the surface in a form that can look initially like a sewage spill. 

There have been no reports of sewage spills, said Brian Humphreys of the Florida Department of Environmental Protection. A sample taken by the state, following a call by nearby residents, was clear of harmful algal blooms and showed no signs of being sewage.