ST. PETERSBURG, Fla. (AP) -- The number of manatee deaths has topped 800 for the first time since such record-keeping began in the 1970s, state wildlife officials said.
According to the Florida Fish and Wildlife Research Institute in St. Petersburg, 803 manatee deaths have been recorded this year. That's about 16 percent of the state's estimated population of 5,000 manatees.
Martine DeWit of the institute's Marine Mammal Pathology Laboratory tells the Tampa Bay Times that 173 of the dead were breeding-age females. It's unclear what effect these deaths will have on the endangered species' population.
Last year, 392 manatee deaths were recorded, which officials consider normal.
The previous record for manatee deaths was 766, set in 2010 after a lengthy cold snap. That cold snap mostly affected younger manatees that had not yet reached breeding age, DeWit said.
Scientists blame a massive bloom of red tide algae along southwest Florida's coastline and a mysterious ailment affecting manatees in the Indian River Lagoon for this year's deaths.
Scores of dolphins and pelicans also have died in the Indian River Lagoon this year, but it's not known whether all the animals' deaths are related. They may be the result of pollution-fueled algae blooms that have wiped out some 47,000 acres of sea grass in the 156-mile-long lagoon along Florida's Atlantic Coast.
There was one highlight among the manatee death reports, officials said. This year, 71 manatees were killed by boat, down from 81 last year and well shy of the record 95 recorded in 2002.