MANATEE -- Officials were cleaning up a fish kill at Anna Maria Island on Tuesday, but its source had not been pinpointed.

Although workers were in the process of cleaning up the north end of Coquina Beach, the situation was "nothing major," said Capt. Joe Westerman, of the Manatee County Marine Rescue division.

Very low to high concentrations of Florida red tide were present along and offshore from southern Pinellas to Collier counties, according to the National Oceanic and Atmospheric Administration.

"Alongshore southern Manatee, Sarasota and Charlotte counties, patchy low respiratory impacts are possible today through Thursday," it reported Tuesday.

The algae bloom of red tide, which results when water temperature and salinity reach a certain point, affected 140 miles of coastline, with the highest counts off Sarasota County, according to the Florida Fish and Wildlife Conservation Commission.

People had experienced slight respiratory irritation, and some dead fish were present last weekend at Coquina Beach, according to Hayley Rutger, a spokesperson for Sarasota's Mote Marine Laboratory.

A report filed at 3:03 p.m. Tuesday at Coquina recorded no respiratory irritation, no dead fish and no red drift algae, according to the website of Mote's Beach Conditions Report.

Mote's other monitoring location in Manatee County, Manatee Beach, did not record any red draft algae, respiratory irritation or dead fish, in a report filed at 11:31 a.m. Tuesday, the website showed.

"However, we always note that conditions can change quickly, so beachgoers -- especially those with asthma or other respiratory problems -- should keep checking www.mote.org/beaches for updates and look at their marine forecast," Rutger said. "Winds blowing onshore tend to give a greater chance of respiratory impacts."

Sara Kennedy, Herald reporter, can be reached at 941-745-7031. Follow her on Twitter@sarawrites.com