ST. PETERSBURG — The latest report on pelicans found sick and dying around the city says dead birds continue to turn up but so far scientists still don't know what's killing them.
"To date we have confirmed reports of at least 70 dead or ill brown pelicans and at least one white pelican," said the report from the Florida Fish and Wildlife Research Institute in St. Petersburg.
Reports about the dead birds have been pouring in since Jan. 11, according to the report. Most of the birds were found around Coffee Pot Bayou, Bayou Grande and the Riviera Bay development's lake, but the most recent one found was a decomposing brown pelican found by Albert Whitted Airport.
Low levels of toxins from an ongoing Red Tide algae bloom were detected in the bodies of some of the dead pelicans, "demonstrating some exposure," the report noted. "These results are inconclusive, neither confirming nor ruling out Red Tide as the cause of death."
Some bird advocates fear what's going on could be linked to St. Petersburg's recent sewage crisis, when the city release tens of millions of gallons of waste into Tampa Bay during last year's storms. So far, though, there is no evidence of a connection.
About 30 birds that were ill were treated by the Seaside Seabird Sanctuary, and the Owl's Nest Sanctuary. The birds were weak or even paralyzed, and some, as they recovered from those symptoms, displayed some disturbing new symptoms such as blinding cataracts.
Owl's Nest hopes to release some of those survivors this week.
Some of the symptoms the survivors displayed could match a diagnosis of poisoning by Red Tide, a toxic algae that has stunk up Florida's beaches with fishkills for centuries. Spanish explorers recorded blooms when they visited in the 1500s.
Small, scattered colonies of the microscopic algae Karenia brevis — named for retired St. Petersburg biologist Karen Steidinger, who spent decades studying it — live in the Gulf of Mexico all year long. Usually they cause no problems.
But every now and then, the algae population offshore explodes into something called a bloom in which the algae multiplies rapidly and spreads. The expanding bloom stains the water a rusty color that gives the creature its name.
No one knows what causes the bloom to begin offshore, and no one knows what causes it to end.
The big blooms release toxins that are deadly to marine creatures. A bloom along the Southwest Florida coast in 2013 killed 200 manatees.
Contact Craig Pittman at firstname.lastname@example.org. Follow @craigtimes.