Will we see more seaweed?

courtesy Tony Haggerty/pexels.com

HOUSTON – I’m not a landscaper but by definition a “weed” is basically anything growing where you don’t want it! And while seaweed has its marine benefits offshore, this nuisance algae is anything but wanted onshore! Not only can seaweed adversely affect corals, but anyone who has had to deal with it knows what a smelly, unsightly nuisance this can be on a beach. And no, seaweed is not a plant but an algae. I’ve had a number of people ask whether we’ll be getting inundated this summer with it.

courtesy Jonathan Borba/pexels.com

The short answer is that the odds are low. To be sure, seaweed (in Spanish called “sargassum”) can originate in the Gulf of Mexico, but most of it comes from the Atlantic in a spot known as the Sargasso Sea. Ocean currents then slowly move the sargassum through the Atlantic into the Caribbean and Gulf, through the Florida Straits and up the Eastern Seaboard. In other words, this mess goes everywhere, and like a Stephen King blob, can get bigger with the right warm water and nutrients!

Seaweed (mostly) originates in the Sargasso Sea and currents move it our way

Fortunately, we can now track the movements and make some predictions as to where the seaweed is likely to end up. I found a website from the Atlantic Oceanographic and Meteorological Laboratory which has great explainers as to what sargassum is and where it might go. The University of South Florida, in conjunction with AOML, publishes weekly forecasts. This map shows the way seaweed has been tracking over the past decade.

This map shows the pathway by which Sargassum exits the Sargasso Sea and makes it's way to the tropical Atlantic and Caribbean Sea. Courtesy AOML

By analyzing satellite info, ocean currents data, field reports and other algorithms, a weekly report called the Sargassum Risk Index is issued with a general Low-Medium-High chance for seaweed. For instance, last week’s report for the Gulf of Mexico looks like this:

courtesy NOAA

You can see our light blue indicates a low risk while the orange medium risk is found in Cuba and South Florida. The red high risk is in Tulum and other islands in the Caribbean. In fact, here’s an article on the Tulum issue.

While experimental, these charts are at least a well-informed forecast for seaweed. Have a look at the website right here and for much more on just what seaweed is and how it affects our world check out this website (teachers, I’m looking at you!). There is a whole list of Frequently Asked Questions with simple explainers so you, uh, don’t get too far into the weeds.



Email me with questions and comments!

About the Authors:

KPRC 2's chief meteorologist with four decades of experience forecasting Houston's weather.

Amanda Cochran is an Edward R. Murrow award-winning journalist. She specializes in Texas features, consumer and business news and local crime coverage.