what you need to know

In recent days, the news has gotten more serious about the kelp “blub” approaching Florida on its Atlantic coast. Sources like South Florida’s NBC 6 report “high numbers” of flesh-eating bacteria in Sargassum seaweed that could seriously endanger all creatures that come in contact with it. These are the ins and outs of what is being reported and what it means.

sargassum seaweed slick on shoreline brown potential carnivorous bacteria florida plastic

Credit: James St. John, Flickr

What is sargassum seaweed?

Sargassum algae is a large brown algae that floats in large blobs together on the ocean surface. It has a foul rotten egg odor and was previously washed up on Florida shores in smaller batches. The algae itself usually can’t harm humans, but the tiny organisms that live inside it can irritate the skin and cause rashes and blisters.

Why is it such a big problem?

The current mass, although currently shrinking, is very, very large, currently 5,000 miles long. Florida Atlantic University found that these seaweeds “can interact with plastic debris in the ocean and deadly Vibrio bacteria to create the perfect ‘pathogenic storm’ for beachgoers.” In combination, this could mean health risks for both marine life and humans.

sargassum seaweed slick on shoreline brown potential carnivorous bacteria florida plastic

Credit: Jimmy Baikovicius, Flickr

What is Vibrio bacteria?

Vibrio bacteria is the leading cause of human death in the marine environment. NBC 6 notes that, “Vibrio vulnificus is a flesh-eating bacterium that can cause life-threatening illness from shellfish consumption, as well as contact with open wounds.” While rare, last year saw an increase after Hurricane Ian, especially thriving in warm standing water. If the bacterium gets into a marine creature that is then eaten raw by a human, this too can be potentially fatal.

“Flesh-eating Vibrio bacteria are colonizing plastic debris in warm ocean water.” Bacteria and microplastic stick very well.

What does an expert have to say?

In theory, the bacteria leaks into the bloodstream and seeks to enter the intestine. It sticks to the intestines, causing infection. NBC 6 cites Tracy Mincer, Ph.D., corresponding senior author and assistant professor of biology at FAU’s Harbor Branch Institute of Oceanography and Harriet L. Wilkes Honors College.

seaweed stain potential sargassum carnivorous bacteria florida plastic coverall

Credit: Daniel/Dan Eidsmoe, Flickr

Mincer says,

For example, if a fish eats a piece of plastic and becomes infected with this Vibrio, causing leaky gut and diarrhea, it will release waste nutrients like nitrogen and phosphate that could stimulate the growth of sargassum and other surrounding organisms… No I don’t think at this point anyone has really considered these microbes and their ability to cause infection. We really want the public to be aware of these associated risks. In particular, caution should be exercised regarding the harvesting and processing of sargassum biomass until the risks are further explored.

Since the bacterium feeds on both plant and animal hosts, contact with sargassum and plastic marine debris can be dangerous to humans.

potential sargassum algae slick carnivorous bacteria florida plastic washed up on shore

Credit: brewbooks, Flickr

What are the risks?

Here’s some information straight from the CDC: When ingested, Vibrio bacteria can cause watery diarrhea, often accompanied by abdominal cramps, nausea, vomiting, fever, and chills. It is responsible for the majority of shellfish-related deaths. Vibrio vulnificus infections lead to necrotizing fasciitis, a severe infection in which flesh around an open wound dies. The results can be life-threatening if ingested or if you come in contact with it.

The Florida department of health notes that people with weakened immune systems and liver problems are at high risk of infection.

Stay safe, bathers!