Tampa Bay may be in the clear of a Red Tide bloom extending from Sarasota to Lee counties.
But that could change depending on the wind and currents, said Alina Corcoran, research scientist for the Fish and Wildlife Research Institute.
"It all depends on Mother Nature," she said.
Models indicate that for the next two days the bloom is expected to head south.
Earlier this week, researchers took samples from beaches along the west coast. Manasota Beach in Sarasota County was among the areas with the highest concentrations. The lowest levels were reported south of there in areas of Lee County, Corcoran said.
The bloom extends about 15 miles offshore of Sarasota County and 25 miles offshore of Sanibel Island. Another patch is located about 35 miles off the coast of northern Collier County, the institute reported.
Samples also were taken in Tampa Bay. Only one, at the Redington Long Pier on Monday, showed low concentrations. No fish kills have been reported along Redington Shores.
A patch that broke off from the bloom and headed north may have caused the low levels in Pinellas, Corcoran said.
The Red Tide forms in the Gulf of Mexico and moves out into the water with the wind and current. Blooms along the west coast of Florida have been known to head as far south as the Florida Keys and into the East Coast, Corcoran said.
The tide produces a toxin that kills fish and other sea animals and can cause respiratory problems in humans.
Researchers are scheduled to do more sampling this week.