Blue-green algae sighting closes Bathtub, Stuart and Jensen beaches, Martin County says

Tyler Treadway | Treasure Coast Newspapers

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Updated story: Algae forces three Martin County beaches to close for swimming Saturday

Bathtub Beach, Stuart Public Beach and Jensen Beach Public Beach in Martin County are closed because of "visible blue-green algae in the water," county spokeswoman Martha Ann Kneiss said Friday afternoon.

The beaches on southern Hutchinson Island were closed to swimming at 2:30 p.m. Friday after County Ocean Rescue Chief Brad Beckett said lifeguards reported seeing algae in the water.

Beachgoers should call the county's beach hotline — 772-320-3112 — to check for updated conditions and closures. Beaches with lifeguards will fly stacked red flags when they're closed for swimming.

Arthur Deschane of Sewall's Point reported seeing possible algae stretching from just north of Stuart Beach to just south of Jensen Beach while kayaking between 11:30 a.m. and 1 p.m. Friday.

"It's about 50 to 75 yards offshore," Deschane said. "First, it's kind of foamy, and then you see curds, or clumps, of green and long strings of it, also green. The farther north you go, the farther it is from shore."

Open-and-closed case

A possible blue-green algae sighting late Tuesday afternoon closed Bathtub Beach, one of the county's most popular tourist destinations, for the rest of that day and through Wednesday.

The beach reopened Thursday after lifeguards gave the all-clear.

More: Bathtub reopens after brief closure from blue-green algae

A Florida Department of Environmental Protection crew took a water sample at Bathtub at 5:22 p.m. Wednesday. The DEP website later reported the sample tested positive for microcystis, a form of cyanobacteria commonly called blue-green algae.

Results of tests to see if the algae is toxic were not available Friday afternoon.

It's uncommon, but not unprecedented, for blue-green algae, which is killed by salty water, to be in the ocean and wash onto Treasure Coast beaches, said Zack Jud, education director at the Florida Oceanographic Society on Hutchinson Island in Stuart.

The massive algae blooms during summer 2016 forced the closings at Bathtub, Stuart, Jensen Beach and Hobe Sound public beaches.

Also that year, mats of algae from the Lake Okeechobee discharges were seen several miles offshore of Fort Pierce, Jud said.

More: Enteric bacteria is another threat to rivers, beaches | Real-time statewide map

Several boaters going to view the sinking Friday of the 99-foot tugboat Penobscot for an artificial fishing reef reported seeing algae blooms 4 miles offshore of the St. Lucie Inlet.

"It's not good news, but it's not at all surprising," Jud said, "that algae that started in Lake Okeechobee was discharged to our St. Lucie River estuary, went out the St. Lucie Inlet and, because of south and southeast winds, made a left turn and ended up on our beaches."

The Army Corps of Engineers increased the discharges Friday morning by about 200 million gallons a day to an average of nearly 970 million gallons a day. More than 55 billion gallons of lake water has been dumped in the St. Lucie River since discharges started June 1.

More: Army Corp increases Lake Okeechobee discharges

Microcystis can tolerate a little salinity, Jud said. "It doesn't die right away, but starts to break down. So the algae we're seeing in the ocean and on the beaches is not healthy; it's dying. The scary thing is that when it dies, it releases its toxins."

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