Show All Answers

1. Where does Sargassum come from, and why is it washing ashore?

Most sargassum grows off the shore of the Gulf of Mexico. Like all plants, it needs nitrogen, phosphorous, and sunlight to survive. In recent years, the sargassum has had its fair share of nitrogen, thriving on large amounts of fertilizer from the runoff of the Amazon River. The seaweed can also increase when upwelling in the eastern Atlantic brings cooler water and nutrients from the bottom of the ocean to the surface.

As the sargassum grows, it starts moving along ocean currents, which transport it from the Gulf to the Florida Current via the Loop Current, and then on to the Sargasso Sea, Tropical Atlantic, and the Caribbean. If winds are strong, it can end up near the Sahara desert, the Amazon River, or here on the Florida coast, bringing problems when it arrives en masse.

2. Why is Sargassum a concern?

• The tiny sea creatures that live in Sargassum can irritate skin with direct contact.
• Decomposing Sargassum causes an unpleasant smell.
• People who live and work near the beach are concerned that Sargassum washing up along the beaches may harm their health.

3. Why does Sargassum smell so bad?

When washed ashore, Sargassum will decompose (rot). Rotting Sargassum causes the production of hydrogen sulfide gas which smells like rotten eggs. 

4. How can hydrogen sulfide affect my health?

Hydrogen sulfide can irritate the eyes, nose, and throat. If you have asthma or other breathing illnesses, you will be more sensitive to hydrogen sulfide. You may have trouble breathing after you inhale it. 

5. Does Sargassum cause skin rashes and blisters?

Sargassum does not sting or cause rashes. However, tiny organisms that live in Sargassum (like larvae of jellyfish) may irritate skin if they come in contact with it.

6. Will hydrogen sulfide from rotting Sargassum cause cancer or other long term health effects?

Hydrogen sulfide is not known to cause cancer in humans. If you are exposed to hydrogen sulfide for a long time in an enclosed space with little air flow (like some work exposures), it can affect your health. However, hydrogen sulfide levels in an area like the beach, where large amounts of air flow can dilute levels, is not expected to harm health. 

7. Can I use Sargassum in cooking?

You should not use Sargassum in cooking because it may contain large amounts of heavy metals like arsenic and cadmium. 

8. How can I protect myself and my family from exposure to Sargassum?

• Always supervise children at the beach.
• Avoid touching or swimming near seaweed to avoid stinging by organisms that live in it.
• Use gloves if you must handle seaweed.
• Stay away from the beach if you experience irritation or breathing problems from hydrogen sulfide—at least until symptoms go away.
• Close windows and doors if you live near the beach.
• Avoid or limit your time on the beach if you have asthma or other respiratory problems.