Massive algal blooms begin to wash ashore on Florida beaches

A massive accumulation of algae that scientists have been tracking for months has begun washing the Sunshine State ashore, with experts warning the worst could be yet to come.

Reports from Key West, Fort Lauderdale and other South Florida communities show clumps of brown seaweed piling up along normally white sandy beaches.

Experts from the University of South Florida and other institutions have been tracking the sargassum using satellites and believe the amount of algae in the Atlantic basin was about 6.1 million tons, the second-highest amount ever recorded in February.

dr Brian Barnes, an assistant research professor in the University of South Florida’s College of Marine Science, is monitoring the algae and believes there should be larger amounts offshore in late spring and early summer.

“Bigger amounts should be off the Florida coast by April through July or so. However, most of this will remain offshore. If the currents and winds require it, a patch can be pushed ashore to affect beaches at a local level,” Barnes said.

According to the Florida Department of Health, the algae is not harmful to humans, but it can still cause adverse effects.

Aside from an unpleasant odor similar to that of rotten eggs, tiny critters that live in the sargassum can cause rashes and blisters.

Health experts advise people never to eat seaweed because it can also contain large amounts of heavy metals like arsenic and cadmium.

In fact, the brown algae are thought to be helpful to many species of marine life, and biologists believe the accumulation provides food and shelter for fish, crabs, shrimp and other smaller organisms.

The sargassum is very different from the red tide, which simultaneously affects Florida beaches, mainly along the Gulf Coast.

Red Tide is a noxious algal bloom discovered in southwest Florida in the days after Hurricane Ian and spread in early 2023.

The ongoing toxic event caused hundreds of fish to wash ashore, and biologists believe even manatees were affected by high levels of the organism known as Karenia brevis.

Specialists have not determined what causes some years to have more extensive algae production than others, but point to a combination of variable factors, including runoff from major waterways.

“It’s hard to pinpoint the cause, but generally blooms will occur if you have the right conditions: temperature, light, a seed, and nutrients,” Barnes said.

Aside from being unpleasant to see and smell, seaweed plumes can cost coastal communities big bucks to clean up, and the events can even drive away tourists.

Efforts in 2018 to rid beaches in the Caribbean of a massive bloom were estimated at more than $120 million by the Global Tourism Resilience and Crisis Management Center, and a study found that a severe sargassum year in south Florida had similar effects would have an impact.

According to a study conducted for the Florida Keys and Monroe County, a major sargassum event could cost the heavily tourism-dependent region at least $20 million in economic losses and hundreds of local jobs.