A foul-smelling toxic blue-green algae known as "Lyngbya" has been spotted in both Treasure Island and Gulfport in recent days, prompting Pinellas County officials to warn the public to steer clear of the stuff.

"You don't want to swim or wade in it or swallow it," county public information officer Tony Fabrizio said Tuesday.

And it's toxic to pets, he said.

The Gulfport bloom, which Fabrizio called "significant," is in the canals just west of the casino. while the Treasure Island bloom is in the Intracoastal Waterway.

County environmental management division director Kelli Hammer Levy said the blooms have been "popping up here and there since May." The explosion of the microscopic organisms is fueled by "warm, calm water" that's been close to 90 degrees in temperature, she said.

But then along came the rains of summer, cooling the local waters down by three degrees or so, she said. Each time that happened, the blooms immediately dissipated. She is hoping something similar happens soon so the latest blooms will disappear as well.

Levy said one theory about the recent Lyngbya blooms is that they are feeding off the nutrients left behind by the recent 14-month long Red Tide algae bloom that at one point was so big it touched all three of Florida's coasts.

The 2014 National Climate Assessment Report predicted that as the globe warms up, more toxic algae blooms would appear in Florida and elsewhere.

The stringy Lyngbya blooms put out an odor that can cause respiratory problems and make your eyes water. They've been showing up more and more recently, including in Lake Okeechobee and in Manatee County. The Manatee River recently turned green because of Lyngbya. In Holmes Beach, Mayor Judy Titsworth has said that longtime island residents just call the stuff "gumbo."

"It makes you want to go inside and close your windows and turn on your air conditioning, because it stinks," Titsworth, granddaughter of the city's namesake, John "Jack" Holmes Sr., said in May.

A blue-green algae bloom on the state's Atlantic coast in 2016 became so thick and noxious that it forced Stuart to close its beaches on the Fourth of July.

Gov. Ron DeSantis recently created a Blue-Green Algae Task Force that has begun meeting to discuss how to stop the blooms. Also known as "filamentous cyanobacteria," Lyngbya can form brownish floating blobs or mats that begin to decay and emit a foul, rotten egg odor caused by the production of hydrogen sulfide gas and other organic breakdown byproducts.

In the early 2000s, outbreaks of a freshwater relative of Lyngbya began to plague such Florida tourist attractions as Ichetucknee Springs and Wakulla Springs in North Florida, causing rashes among swimmers. That was Lyngbya wollei, which grows in dense mats at the bottoms of some lakes and spring-fed systems. These mats produce gases that can cause the mats to rise to the surface, where winds pile them against shorelines. A 2000 state study of Kings Bay in Citrus County found that Lyngbya had already spread to the point that it "dominated areas of Kings Bay causing habitat destruction, navigation and recreational use impairment and odor problems."

Contact Craig Pittman at craig@tampabay.com. Follow @craigtimes.