My mom is an expert (and thanks to her, my daughter also) at making meringue. If you’ve ever attempted this pie topping, you know there’s a bit of an art to it. At its core, meringue is simply the raw protein of an egg white and some added sugar, beaten consistently at a high rate to incorporate air. It’s the air that causes the egg/sugar mixture to transform from a clear liquid to a foamy, white semisolid that stands upright when touched.
This baking technique is essentially what has happened when you see foam forming along the coast, floating in with the waves, and drifting onto the beach. At some location offshore, there’s likely been excess growth of algae, and that mixture of dissolved organic material and proteins plus the salt, minerals, and other vegetation in the water have churned with a storm or heavy wave action. Just like mom’s meringue, air is whipped into the liquid and out comes a thick foam. On the Gulf Coast, our sea foam deposits are soapy-looking and relatively low key when compared to some of the massive occurrences off the coasts of California and Australia. A sea foam “event” caused by a tropical storm on the eastern coast of Australia in 2013 brought in thick mats of foam several feet deep—along with sea snakes hidden in the mix!
Generally speaking, sea foam is harmless and only composed of the same materials you’d wade into while swimming in the Gulf. The only time you’d need to take caution is when the foam is associated with a harmful algal bloom. The algae Karenia brevis causes red tide and possesses toxins that can cause allergic reactions, including itchy, watery eyes, and respiratory problems (particularly for individuals with asthma). When air bubbles in sea foam burst, more of the toxins can be released.
Thankfully, red tide events are relatively short-lived in the Panhandle. When we do have blooms, it is usually all over the news and social media, in addition to purple flags (indicating dangerous sea life) and warning signs physically placed on the beach. You can also check the weekly red tide update from the Florida Fish and Wildlife Conservation Commission for accurate information.
If there is no indication of red tide or other harmful algae species in the area, the regular sea foam churned up on the shorelines is as common and harmless as the shells nearby.