Sarasota, Florida -- The large red tide bloom that researchers are tracking continues to move south and has now been detected off of Pinellas County, 13 miles west of Madeira Beach and 33 miles west of Caladesi Island.
Low concentrations were found off of Caladesi, and trace amounts were detected off of Madeira, according to the Florida Fish and Wildlife Conservation Commission.
Thousands of dead fish are being reported, including deep-water species such as grouper an snapper.
FAQs: What is red tide?
The bloom has been estimated at about 80 miles long and 50 miles wide, according to satellite images from the University of South Florida.
Researchers with Mote Marine Laboratories in Sarasota headed north Thursday to learn more about the bloom.
A team of four researchers gathered data and water samples from 12 locations ahead of the bloom between Sarasota and Hernando. Researchers say they took several samples at each stop from the surface to about 100 feet deep. From there, scientists will measure toxin levels and cell counts from each sample.
Then, scientists headed into the heart of the bloom where they saw the effects of the bloom.
"They did see some scattered fish, some larger fish -- I'm not sure of the species at the moment. They saw discolored water, the characteristic dark brown water indicative of red tide. They did notice a little bit of respiratory irritation when they sat on station. And all this was at the one station farthest into the bloom," says Vince Lovko, a researcher with Mote Marine Laboratories.
Lovko says the data gathered will help scientists better predict the movement of the bloom on the surface and below the surface.
He says some of the test results from the water samples may be ready Friday, in time for FWC's weekly report. The rest of the data won't be ready until next week.
Lovko says he will be joining FWC and other scientists this Sunday, Aug. 3 for a 3-day expedition to the bloom.
It is also bad for business. Places like Original Pizza and Hubbard Marina at John's Pass depend on summer tourist dollars to make ends meet.
"Red tide would be horrible for us. It's smells bad and it's terrible for the fisheries," said Mark Hubbard, owner of Hubbard Marina.
For more information, call the FWC Red Tide Status Line: 1-866-300-9399.