(CNN) As the red tide continues to move northward along Florida's east coast, a new breakaway bloom is moving through the Keys.

Counties across the state have been dealing with the Karenia brevis algae, and the marine life it's killed, for months. Now, Indian River is the latest Florida county forced to close its beaches because of red tide.

And on Tuesday, Brevard County's Melbourne Beach, Indialantic and Cocoa Beach also confirmed their waters, too, have tested positive for medium levels of the toxic algae. Officials said their counties' beaches would remain open, but signage would be put up warning of red tide's presence.

Gemini Elementary School in Melbourne Beach has canceled all outdoor activities for its students until red tide moves from the area. Brevard County Public Schools will meet later Thursday to discuss steps they may take.

Red tide's neurotoxins are deadly to marine life and can irritate people's skin; it can even cause respiratory issues, especially for people with asthma.

A University of Miami professor of marine biology and ecology, Larry Brand, told CNN previously that "It's like being hit with a tear gas."

Leaders of Florida's Fish and Wildlife Conservation Committee say they've received reports of respiratory irritations in Pinellas, Manatee, Sarasota, Lee, Collier, Escambia, Okaloosa, Brevard and Indian River counties.

Fish choked by red tide have washed up on beaches across the state; FWC says Pinellas, Manatee, Sarasota, Lee, Collier, Escambia, Okaloosa, Brevard and Indian River counties reported fish kills from red tide.

Video posted by the Sebastian Daily shows dead fish washed up in Sebastian Inlet, Florida.

Although red tide can occur naturally in Florida, many scientists blame agricultural runoff and septic tanks for fueling the nitrogen-consuming algae.

Earlier this month, Florida Governor Rick Scott gave $3 million in grants to St. Lucie, Martin, Palm Beach, Broward and Miami-Dade counties to respond to red tide, which he called the "natural phenomenon."

At this time, Collier, Lee, Charlotte, Sarasota, Manatee, Hillsborough, Pinellas, St. Lucie, Martin, Palm Beach, Miami-Dade, Brevard and Indian River counties are all now under states of emergency because of red tide.

"Governor Scott has taken swift action to combat naturally occurring red tide in Florida," McKinley Lewis, a spokesperson for the governor, told CNN in an email. "The state has committed more than $13 million in grants to local governments battling red tide, and currently, there is $2 million available to Indian River and Brevard Counties. We are working cooperatively with these counties to ensure that this funding is used to help mitigate the impacts of this phenomenon."

VisitFlorida, the state's official tourism marketing corporation, is currently surveying the impact red tide is having on businesses in Florida.

Hurricane Michael didn't break up the red tide

Some had hoped that the wind and swells from Hurricane Michael would help dissipate the red tide. That is not the case.

"Testing right now indicates that it looks the same now as before Michael," NOAA oceanographer Richard Stumpf told CNN. "Michael didn't change the bloom. Didn't make it worse. Didn't make it better."

Off the coast of Fort Walton Beach and Santa Rosa County, closer to where Hurricane Michael came onshore, red tide levels are still elevated.

However, there is a gap in water testing in Florida's panhandle around the worst hit areas.

"We are working with our sampling network to get additional samples as people get back out on the water," Florida Fish and Wildlife Conservation Commission's Kelly Richmond told CNN.

The worst hit areas, from Pinellas to Sarasota counties, are still seeing medium to high levels of red tide. The highest levels measured in Tampa Bay and St. Petersburg.

FWC's forecast calls for continued red tide on Florida's Panhandle and west coasts.

While there is no official forecast for the east coast, Stumpf believes that currents around Cape Canaveral could help tear apart red tide there.

Indian River Lagoon could be problematic.

There's a chance the red tide could spread into the body of water already inundated with three other types of harmful algae blooms: brown tide, blue-green algae and a recurrent summertime bloom of pyrodinium algae.

"Very low probability," said Dr. James Sullivan, Florida Atlantic University's Harbor Branch Oceanographic Institute's executive director. "But never say never."

More breakaway red tide in the Florida Keys

Stumpf blames Florida's east coast red tide bloom on the state's west coast red tide bloom. Water currents carried a cluster of the bloom south, through the Florida Keys, and onward to Fort Lauderdale, then to Miami's beaches.

Since then, it's floated north and is choking the waters off Florida's Space Coast.

The latest red tide forecast for Florida.

Researchers are now tracking more breakaway red tide in the Florida Keys that could inundate Florida's east coast with more algae. It, too, was picked up from the west coast's red tide.

Measurements of red tide levels in the Florida Keys have been at low and very low concentrations, according to state officials.

The conditions for it to be transferred to the east coast, again, have to be perfect.

"We'll just hope for the best," Stumpf said.

Tracking the red tide around the southern tip of Florida is difficult because it's hard to pick up on satellite imagery.