In his usual 9 a.m. shorebird survey around Caladesi Island on Wednesday, Dan Larremore saw something that was off: dead red knots.
While most of the birds in the flock of hundreds were fine — there were a few that weren't acting right, he said. They looked lethargic. Some of them couldn't move their feet.
"They were obviously affected by something," said Larremore, the Honeymoon Island State Park biologist.
The Clearwater Audubon Society reported that as of Thursday, 14 shore birds were dead and 12 others sick in northern Pinellas County. While mostly red knots have been found ill, Barbara Walker with the Audubon Society said other shore birds have been affected, too.
But what exactly is causing them to fall ill was unclear.
"There's still a big question," said Indian Shores' Seaside Seabird Sanctuary manager Eddie Gayton. "But it's a good possibility it's a toxin."
In addition to Caladesi, sick and dead shore birds have been reported in Belleair Beach, Sand Key and Anclote Key.
Gayton and his team had nine birds in their care on Thursday, with one other on the way. He said the birds were being treated to remove the possible toxins.
"I'm optimistic," Gayton said. "They look like they're starting to react positively."
Walker said the way the birds are acting is consistent with how they would respond to Red Tide, an algae bloom that can occur along the Gulf Coast. The Florida Fish and Wildlife Conservation Commission's last round of water testing done on Aug. 18 showed no sign of Red Tide, or Karenia brevis. There are reports, however, of a multi-species fish kill in Old Tampa Bay associated with a different bloom that lessens oxygen in the water.
FWC is testing the water where the birds were found for algae and other toxins. One of the dead birds has been sent to a veterinarian at Busch Gardens for a necropsy.
Rescuers are waiting for answers while the birds mend.
Red knots are migratory birds that nest in the Arctic tundra. They come to Florida to feed on horseshoe crab eggs.
"They stop at our islands to fuel up for their journey," Larremore said.
A few of the small birds sat wrapped in towels as they rested their gray feathers at the sanctuary late Thursday afternoon.
"They're really super cute little birds," Walker said.
Any distressed or dead shore birds can be reported to Walker at (727) 798-2385.
Contact Sara DiNatale at email@example.com. Follow @sara_dinatale.