If you’ve made a trip to Galveston Island recently, you may have noticed large mounds of smelly sargassum, a unique type of seaweed that washes ashore. But is it harmful? And why are we seeing so much of it? KPRC 2’s Bill Barajas set out to learn more.
The sargassum is just about everywhere, blanketing beaches on the island. Many areas, like Seawall Boulevard and 14th Street, are left looking uninviting due to the unpleasant smell. Experts say we might see even more of it washing up in the coming months.
As summer approaches, many people are planning trips to Galveston Island.
“I like the beach. I’ve been coming since I was six years old, and now I’m 61,” said Patti Hudgins.
Visitors will surely find sunshine, sand, and waves, but they will also encounter large brown mounds of smelly seaweed.
“It’s kind of nasty, but overall it’s not too big of a problem,” said Hannah Hudgins.
Anna Armitage, a professor of marine biology at Texas A&M Galveston, explains that there has been a rise in sargassum in recent years.
“Sargassum is unique because it floats. Most of the time, you get big mats of sargassum out in a part of the Atlantic Ocean called the Sargasso Sea,” she said.
In 2014, sargassum levels reached record highs. When asked if we are nearing that level in 2025, Armitage said, “It’s a little too early to tell, but there are certainly signs that there’s going to be a lot of sargassum this year. It’s important to remember, though, that it doesn’t persist for long periods. It will come in waves, and eventually, it will decompose. It might stink a little bit while that happens, but in the meantime, it’s providing ecological benefits to the shoreline.”
She added that conditions are just right for sargassum growth when the temperature is warm and there are enough nutrients to fertilize the plants. “It’s salty enough, but not too salty, so when all of these things align, then the sargassum can really grow very well,” Armitage explained.
While the odor may be unpleasant, Armitage reassured that sargassum is not harmful to humans. “Once it washes up on the beach, it does die,” she said. “There are a lot of ecological benefits to sargassum. When it’s out in the water, it provides food and shelter for all kinds of animals, including juvenile fish that people like to fish when they’re bigger. Here on the beaches, yes, as it decomposes, it adds nutrients and fertilizes the soil and helps stabilize the dunes. It actually is good for the stabilization of the shoreline.”
Chris Stanley, a spokesman for the Galveston Park Board, noted that sargassum cleanup is ongoing.
“You mentioned to me you’ve already picked it up once this year in parts of it,” Barajas asked. Stanley responded, “Once you do pick it up, what do you do with it? We just push it back up against the seawall because it’s a very important part of the ecosystem. We need that to help break down because when it breaks down, it helps build up the dunes and keeps the beaches safe.”
Sargassum season can start in April and last until June or July. The Galveston Park Board says they will continue to monitor the situation, hoping it won’t negatively affect tourism.