Sargassum

What is sargassum?

Sargassum is a type of floating brown macroalgae (seaweed) that provides food, protection and habitat for many marine species. Sargassum plays an important role in the health and biodiversity of open ocean ecosystems.

Is sargassum on beaches unusual?

Sargassum washing ashore isn’t uncommon. Typically, Florida’s Atlantic-side shorelines see increases in sargassum arrivals beginning in the early spring. Winds out of the south and east push larger concentrations of sargassum onto beaches and shorelines.

Is there anything beneficial about sargassum?

Sargassum can be a valuable part of the marine ecosystem. As it moves with tides, currents and wind, it can provide a safe haven and important habitat for sea turtles and fish. Instead of avoiding it, anglers actively seek patches of sargassum in the Gulf Stream and nearshore waters because it can provide shade for baitfish, which attracts gamefish such as mahi-mahi, known more commonly in the Keys as dolphin, a highly prized gamefish.

Will sargassum be removed from Keys beaches?

Monroe County, along with the cities of Key West, Marathon, Key Colony Beach and the Village of Islamorada have beach cleaning programs in place for public beaches and parks in their jurisdictions. Typically, private oceanfront and bayside resorts have their own beach cleanup programs.

Why does sargassum smell so bad?

When large amounts of sargassum wash ashore and decays in the sun it causes the production of hydrogen sulfide gas, which smells like rotten eggs.

Should people avoid sargassum?

The accumulation of hydrogen sulfide gas may cause headaches and create health issues for some humans who have chronic respiratory problems. Sargassum itself does not sting or cause rashes. However, tiny organisms that live in sargassum (like larvae of jellyfish) may irritate skin if you come in contact with it. More information is available on the Monroe County Florida Department of Health website.