Toxic algae in St. Lucie river and canal are in dangerous concentrations, DEP confirms

Algae in the St. Lucie canal and river is toxic in concentrations that are dangerous for people, pets and wildlife to touch, ingest or inhale, but the Army Corps of Engineers has not said it will stop Lake Okeechobee discharges.

The Florida Department of Health issued a health alert Friday after confirming the toxin microcystin in at least three locations, including two that are over 8 parts per billion, which the Environmental Protection Agency says is harmful:

• St. Lucie Canal (C-44) at the 96th Street bridge: 17 parts per billion
• St. Lucie River at Four Rivers in Palm City: 11 parts per billion
• St. Lucie River at the Palm City Bridge: 0.92 parts per billion

Toxic algae:Mast, SFWMD say Army Corps should stop Lake O discharges

DEP is awaiting test results for three other locations it tested this week:

• St. Lucie River at the Harborage
• St. Lucie River at the Seagate Harbor boat ramp
• St. Lucie Canal at the Army Corps campground

The Army Corps had scheduled a routine two-week pause in discharges starting Saturday, but has not said what it will do after that. Col. James Booth on Thursday said it could be a week before he decides.

"We're absolutely going to consider algae," Booth said Friday. "We're already looking at what traditional algae bloom seasons look like and how that will affect a decision."

Toxic algae comes from Lake Okeechobee

The toxin is in microscystis aeruginosa, technically a cyanobacteria commonly called "blue-green algae." Lake Okeechobee water that's discharged east can carry the algae into the C-44 Canal, St. Lucie River, Indian River Lagoon, St. Lucie Inlet and the Atlantic Ocean, as it did in 2018, closing beaches on the July 4 weekend.

Guacamole-thick, putrid-smelling algae, which contains ammonia and hydrogen sulfide, slimed the Treasure Coast during the "Lost Summers" of 2005, 2013, 2016 and 2018. The algae has not been found in the St. Lucie River during years when Lake O discharges did not take place.

Lake O discharges have been taking place for 41 days beginning Feb. 17. Nearly 56.2 billion gallons of water has moved from the lake into the brackish St. Lucie River estuary this year. For much of the past month, salinity levels near the Roosevelt Bridge in downtown Stuart have been near 0 parts per thousand, about 25 parts per thousand lower than usual for this time of year. Sea water is about 32 parts per thousand.

The algae is a freshwater organism that dies when exposed to saltwater for long periods of time. Salinity below 5 arts per thousand for extended periods can kill oyster spat and harm adult oysters.

Harmful algae blooms (HAB)

The health department advises people to take these precautions during discharges:

• Do not drink, swim, wade, use personal watercraft, water ski or boat in waters where there is a visible blue-green algae bloom.
• Wash your skin and clothing with soap and water if you have contact with algae or water that's discolored or smelly.
• Keep pets away from the area. Water containing algae blooms are not safe for animals. Pets and livestock should have a different source of water when algae blooms are present.
• Do not cook or clean dishes with water contaminated by algae blooms. Boiling the water will not eliminate the toxins.
• Eating fillets from healthy fish caught in freshwater lakes experiencing blooms is safe. Rinse fish fillets with tap or bottled water, throw out the guts and cook fish well.
• Do not eat shellfish in waters with algae blooms.

How to report algae blooms 

• DEP collects and analyzes algal bloom samples. Report algae sightings to DEP online or via its toll-free hotline at 855-305-3903.
• Report fish kills to the Florida Fish and Wildlife Research Institute at 800-636-0511.
• Report symptoms from exposure to an algal bloom or any aquatic toxin to the Florida Poison Information Center at 800-222-1222.
• Contact your veterinarian if you believe your pet has become ill after consuming or having contact with water containing cyanobacteria (blue-green algae). If you have other health questions or concerns, call DOH-Martin at 772-221-4000.

Ed Killer is an environmental reporter for TCPalm. Email him at ed.killer@tcpalm.com.