Sea foam floating in St. Johns River: Should we be concerned?

You might have noticed sea foam floating in the St. Johns River recently. Although most sea foam isn't harmful to humans or the environment, it sometimes can be a sign that something is off.

JACKSONVILLE, Fla. – Have noticed foam floating in the St. Johns River?

It is commonly seen during red tide, but experts said Jacksonville doesn’t have too much to worry about.

News4JAX spoke with Dr. Quinton White, the Executive Director of Marine Science Research at Jacksonville University, who said most sea foam isn’t harmful to humans or the environment. It’s natural, but in rare instances, it can be a sign that something is off.

According to White, sea foam is caused by algae decaying offshore.

“Many people have been to the beach and seen sort of billows of foam blowing off the surf and it’s very harmless there’s nothing to worry about,” White said.

Sea foam forms when tiny organisms die and the oils and other matter they leave behind wash towards the shore -- add in some wind and it becomes foam. “Seawater contains dissolved salts, proteins, fats, dead algae, detergents and other pollutants, and a bunch of other bits and pieces of organic and artificial matter,” the National Oceanic and Atmospheric Administration said.

“Generally these are fairly normal responses to what I call sort of life of death in the river,” White said. “It’s nothing to be alarmed about.”

Most sea foam is not harmful to humans and is often an indication of a productive ocean ecosystem. But when large harmful algal blooms decay near shore, there are potential for impacts to human health and the environment, NOAA said.

Dr. White said if you notice enormous amounts of sea foam or it’s an odd color you should call a nearby environmental protection agency because it could mean that someone has released a detergent into the river or there’s something else going on.

It’s important to remember the harmful algae that causes most red tides in Florida is found almost exclusively in the Gulf of Mexico. It has been detected on Florida’s Atlantic Coast fewer than a dozen times in the last 70 years.

Click here to read more about sea foam.

About the Author: