Foam on the Water, C-24 Canal, St Lucie River/Indian River Lagoon

Foam floating on water at C-24 Spillway. (Photo Dr.Dave Carlson, September 9, 2015)
Foam floating on water at C-24 Spillway. (Photo Dr.Dave Carlson, September 9, 2015)


Just a few days ago, friend, and sometimes vet to our dogs, Dr Dave Carlson, sent me some unusual photographs of foam pouring out of the St Lucie River’s C-24 spillway, managed by the South Florida Water Management District.

Dave wrote: “Hi Jacqui, was out this am and shot these on the C24 canal. “Iceburgs” in the canal! Real time follow-up to your blogs on these canals.”

“That’s really weird,” I thought. “Foam everywhere!”

I remember foam building up along the shoreline at Stuart Beach periodically when I was a kid. We would pick it up in our cupped hands and throw it at each other; it was great fun. I never knew what formed it though. Was it pollution? It looked kind of gross….

I wrote Dave. “Where is it; and what is it?” I asked.

He replied: “At the spillway going into the North Fork. Are a result of decayed plant and animal protein according to SFWMD. Tyler Treadway did a piece on this after tropical storm Fay, 2008.”

Hmmm? I thought. Decaying plants and animals?…Bizarre. I looked up the TCPalm article, it had one quote regarding foam:

Foam C-24 photo by Dave Carlson, 9-9-15.
Foam C-24 photo by Dave Carlson, 9-9-15.
Form at C-24 spillway. (Photo Dave Carlson 9-9-15)
Form at C-24 spillway. (Photo Dave Carlson 9-9-15.

“What you’re seeing is denatured protein,” said Boyd E. Gunsalus, lead environmental scientist for the South Florida Water Management District’s office on the Treasure Coast, “which is the result of decaying plants and animals.”

That’s nice, and Boyd is awesome. But what does that mean? What are “denatured proteins” and how do they get “denatured?” So I looked them up too. You have to put on your eighth grade science cap! Basically, I think, a denatured protein is an unfolded protein that can then bond with other things to form something else… this case causing foam.


What? But how does that happen?

Now we have to learn, or remember, yet another odd word…. 🙂

In order for the foam to form, and the proteins to “denatureate,” there has to be a “surfactant,” in the water.

Yikes! This sounds like a project for the River Kidz! My science skills are rather rusty! Please share more if you know how this all works!

A surfactant is something that lessens the surface tension on the surface of the water….

According to my reading, the natural surfactant is called DOC (dissolved organic carbon). DOC comes from the decomposition of a wide variety of plant material including algae, decaying animal protein, and aquatic plants…

So to summarize:  the surfactant effect caused by decaying protein bonds and agitation of wind and rain forms foam. This is the basically same phenomenon that happens with detergents and “dirt.” Detergents are also surfactants. There are natural and man-made surfactants. What’s occurring in the SLR is “natural.”

Well that was fun. Leaning about something that looks like pollution in the St Lucie River but isn’t, what a rarity. Nonetheless, I would think all the pollution in the water really helps “stir things up!” Read about it here, these DEP reports are “old” but nothing has changed much so they still apply:

DEP C-24 Eco-summary: (

Thank you Dr Dave! Great citizen’s report! Good work for the St Lucie River/Indian River Lagoon!



A Passion for Nature: (

TCPalm, 2008, Tyler Treadway, (

Town of Skaneateles, NY:  (
Video shared on Facebook 9-24-15 by Trena Merendino. C-23 canal with lots of foam: (

12 thoughts on “Foam on the Water, C-24 Canal, St Lucie River/Indian River Lagoon

  1. I just came back from our EauGallie causeway. We had a slight Northeaster this morning and for a quarter mile long stretch there is lots of foam from waves beating against calcium barnicals. Minnows —minnows and more minnows and all of them feeding on the calcium rich food coming from this sea wall.

  2. I have seen wadeing birds with 5 or six in their mouth at the same thime. There is a little bird that has learned to stand on the pelicans head an pick the little minnows that are hanging half out as he sieves the water out. I hope to get a picture

  3. I don’t think one person(other than me) has made a comment on your blog since you went to Appalachacola. Hopefully they are all doing their homework to see if I am feeding them fertilizer.. I just came back from our public fishing pier and saw that a guy had caught a specald trout (about 7 pounds).

  4. Good question shrubqueen——–There used to be a radio show called Paul Harvey and on his show he allways said—-and now the rest of the story—- Of course the foam is decaying plants and animals but the reason it is NOW decaying is calcium is reacting with acids and forming hydrogen peroxide and calcium peroxide. Neither plant or animal cells could break down without oxygen. This is how our lagoon used to be able to support life on a scale that was hard to believe.Hydrogen peroxide reacts violently with organic material.All your pesticides –herbicides and fertilizers will also decompose

  5. I believe amendment one is called the clean water act. I don’t know how anyone can begin to think there is going to be clean water without this chemical reaction going on ,on the shores of our lagoon

  6. Years ago I remember reading an article that said Saddam Husain wauted to hurt the Kurds the worst way possible and some British engineers came up with a plan. (back when Sadam was a ally of the West) The Kirdish people feed there familys by fishing in the marshs. If you waunt to destroy the Kirds the most effective way to do this is by draining the Marshs. It worked. I believe history is going to show what has been done to the citizens of Florida by the State government has been far more effective than what Saddam did to the Kirds.

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