Some cultivation-based data show beached Sargassum appear to harbor high amounts of Vibrio bacteria. Photo: Brian Lapointe/FAU Harbor Branch
If you’re a person who peruses the internet, you’ve likely heard about the giant seaweed blobs that were headed towards Florida. Well, it’s no longer heading towards Florida… because it has made landfall. Researchers studying seaweed from the Sargasso Sea found something rather alarming: multiple species of Vibrio bacteria. Vibrio isn’t anything to sneeze at, unless you want your nose to fall off. It can can lead to necrotizing fasciitis, also known by the slightly more terrifying name of flesh-eating bacteria.
These enormous seaweed blobs are getting more and more common as the global average temperature rises. The warming oceans lead to spikes in sargassum seaweed mega-blooms. But it’s not just the warmth — it’s also runoff from heart-rivers like the Amazon and the Mississipi. See, the millions of other smaller rivers running into those giant ones are often full of pesticides and other things that farmers use to boost crop growth. They get into the ocean and ramp up seaweed growth. And while growth can be good in business and our personal lives, rampant growth can also be extraordinarily harmful in nature. Those huge patches of seaweed sap nutrients and oxygen from places that need it and can choke out entire ecosystems like weeds in a vegetable garden.
Researchers digging through the giant carpets of seaweed were worried that they might contain a few things that aren’t good for us, and they were right. We humans, however, are not vegetable gardens. And although we should be worried about our vegetables being choked, that whole flesh-eating bacteria thing is a little more alarming, especially given that there are vast quantities of sargassum piling up on beaches worldwide.
The vibrio species of bacteria — a particularly nasty little bug — were found across multiple samples. Vibrio isn’t picky about what it infects. From plants to animals (which is us), it can survive in harsh environments with limited nutrients. Salt water or fresh, vibrio doesn’t care. Which is why the public is being warned to stay away from the mountains of seaweed landing on beaches, especially in Florida.
“I don’t think at this point, anyone has really considered these microbes and their capability to cause infections,” said Tracy Mincer, Ph.D., corresponding lead author and an assistant professor of biology at FAU’s Harbor Branch Oceanographic Institute and Harriet L. Wilkes Honors College, in a statement. “We really want to make the public aware of these associated risks. In particular, caution should be exercised regarding the harvest and processing of Sargassum biomass until the risks are explored more thoroughly.”
Luckily, most people already stay away from huge piles of seaweed. The smell is generally bad, the texture is gross, and the flies love it. Still though, sargassum is a necessary piece of our world, just like everything else. Sargassum fish call it home. Juvenile animals of many types use it for protection. As it ages, it sinks to the seafloor and becomes a huge part of the deep sea food web. But as things stand now, maybe don’t go flinging yourself into a massive pile of slimy, stinking seaweed. There’s a chance you could catch a bug that’ll eat your flesh.
