Red Drift Algae Washed Up on Shores After Tropical Storm Cristobal, Are They Safe?

A type of seaweed that grows on the bottom of local beaches is piling up on local beaches after the tropical storm Cristobal.

Rick Bartleson, a chemist and water quality scientist at the Sanibel-Captiva Conservation Foundation on Sanibel, said that these slippery, slimy, and a little funky smelling red drift algae is not toxic like the red tide.

Many people like eating seaweed salad, but Bartleson warns that it is not the type that anyone would want to eat. He said that these red drift algae found on the shore are already full of bacteria because a pelican might have pooped on it, and the bacteria from it continues to survive on the algae.

Red drift algae grow on the harder bottom surfaces, but they get uprooted when strong currents and waves hit the shores, just what happened two weeks ago when tropical storm Cristobal passed through the Gulf of Mexico.

Unlike the red drift algae, the red tide is caused by a microorganism called Karenia brevis, which is naturally found at background levels in the Gulf of Mexico.

Non-toxic Red Drift Algae Blankets Southwest Florida

From the fall of 2017 until the spring of 2019, red tide bloom blanketed the Southwest Florida which killed millions of pounds of marine life, and nearly emptied the local beaches in 2018.

Typhoon storm Cristobal made landfall in Louisiana, but the storm's impact was also felt in the area. The National Weather Service has issued high surf, and small craft advisories as waves pounded local beaches for many days.

Due to the high energy from the storm, the red drift algae break loose from the bottom surface - where it was commonly found- and washed up on local beaches and can still be found today along the high tide line.

Red drift algae are stringy reddish-to-brown seaweed that traps shells and other marine debris and creates a habitat for small creatures that serve as food for shorebirds.

Jim Culter, a scientist at Mote Marine Laboratory and Aquarium in Sarasota, said that red drift algae are pretty common, particularly during the summer months.

"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," Culter said.

Luckily, conditions now are relatively mild compared to previous years, where patches are much dense and stronger that have suffocated local beaches in recent years.

The Red Drift Algae From the Bottom of the Water

When red drift algae drift to the shore, small bulldozers and other heavy equipment have been used to remove mounds of these seaweeds.

As the name suggests, they drift along from the bottom of the water column, rolling around like a marine tumbleweed. Sometimes, clumps of red algae would look like a stationary manatee because of their size and dark coloration. There are also times when they can cause temporary localized water quality issues.

"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," Culter said.