Harmless red drift algae piling up on local beaches in aftermath of TS Cristobal

It's slippery, slimy and a little funky smelling, but red drift algae that is piling up on local beaches is not a hazard to wildlife or people. 

A type of seaweed, red drift algae grows on the bottom off local beaches. 

"It’s not toxic like red tide," said Rick Bartleson, a chemist and water quality scientist at the Sanibel-Captiva Conservation Foundation on Sanibel. "You don’t want to eat it. Some people eat seaweed salad but you don’t eat this off the beach because it’s full of bacteria. So if a pelican poops on it, the bacteria from the poop will continue to survive on the algae." 

Red drift algae grows on harder bottom surfaces and gets uprooted and dislodged when strong currents and waves pound the shores, which happened nearly two weeks ago when Tropical Storm Cristobal passed through the Gulf of Mexico. 

Red tide is caused by an organism called Karenia brevis and is found naturally at background levels in the Gulf of Mexico. 

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A red tide bloom that blanketed Southwest Florida and stretched from the fall of 2017 to the spring of 2019 claimed millions of pounds of marine life, and nearly emptied local beaches during the summer of 2018. 

Cristobal made landfall in Louisiana, but the impacts were also felt here. 

High surf and small craft advisories were issued by the National Weather Service, and waves pounded local beaches for several days. 

The energy from the storm was strong enough to cause the drift algae to break loose from the bottom. It washed up on local beaches and can still be found along the high tide line. 

Red drift algae looks like a stringy reddish-to-brown batch of, well, seaweed. 

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It traps shells and other marine debris and creates habitat for tiny creatures, which serve as food for local shorebirds. 

"It’s pretty common, particularly when you get into the summer months," said Jim Culter, a scientist at Mote Marine Laboratory and Aquarium in Sarasota. "Pretty much all the larger stuff starts out attached to the bottom; and with increased sunlight in the spring, it begins a new growth spurt. When it gets big enough it breaks loose and washes around in currents and waves." 

Conditions now are relatively mild, compared to much stronger, more dense patches that have suffocated local beaches in recent years. 

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At times, small bulldozers and other heavy equipment has been used to remove giant mounds of festering red drift algae that had been raked up from areas like Fort Myers Beach. 

As the name suggests, red drift algae drifts along the bottom of the water column, rolling around like an aquatic tumbleweed. 

Some clumps look like a stationary manatee because of their size and dark coloration. 

Larger masses in deeper waters can cause temporary localized water quality issues. 

"They’ll continue to grow in the water and in underwater areas that are not heavily influenced by wind, waves and currents," Culter said. "The red (drift) algae can accumulate in deep areas. It still grows but kind of rots on the bottom and increases the demand on dissolved oxygen and that can be to the detriment of water quality." 

Bartleson said the strands of drift algae create a web of organic material. 

"Any extra amounts of current will dislodge the algae," he said. "When the clumps get large they have more drag, and that’s important when there’s more current out there." 

Connect with this reporter: @ChadGillisNP on Twitter.