AUDIE CORNISH, HOST:
From NPR News, this is ALL THINGS CONSIDERED. I'm Audie Cornish.
ROBERT SIEGEL, HOST:
And I'm Robert Siegel.
In Florida, it's been a bad year for the endangered manatee. More than 400 have died so far in the state's waterways since January. And the main cause is not boat propellers, as has often been the case. It is algae.
Ashley Lopez of member station WGCU has the story from Fort Myers.
ASHLEY LOPEZ, BYLINE: On the Caloosahatchee River in southwest Florida, there's a power plant which discharges warm water into the river. The area is called Manatee Park. It's named after the large, peaceful marine mammals nicknamed sea cows that hang around here during the winter.
(SOUNDBITE OF MOTORBOAT)
LOPEZ: Florida Fish and Wildlife officer Steve Rice fires up his boat and scours the river. It's not a fun assignment. He's looking for dead manatees and has found more than 20 in the past few weeks, including several on this trip.
STEVE RICE: We are coming up to it now. You can see it has some spots on it that are a little darker, where it has been sitting out of the water for a little while. And the rigor mortis has kicked in, so its flippers are sticking up in the air.
LOPEZ: It used to be boat propellers were the biggest killer of manatees. But an algae bloom called red tide has been especially bad this year. Rice says it's been tough.
RICE: Its part of the job, but it's not something we like doing. It's pretty terrible. And we have to come out and dedicate a day of our job to searching for sick or injured animals. So I can't wait for this to end.
(SOUNDBITE OF MOTORBOAT)
LOPEZ: Rice ties up the 500 pound manatee to one side of his boat. Another dead manatee he picked up earlier is on the other side. He says most of the deceased manatees are being reported by people kayaking in the river.
Tim Martell, who leads manatee kayak tours, says the past few months have been devastating.
TIM MARTELL: I think that it's terrible. Red tide is something that is not good for the ecosystem overall, and obviously not for these animals that are dying from it.
LOPEZ: It's impossible to contain or control red tide. The blooms occur naturally almost every year along Florida's Gulf Coast. The algae produce toxins that are absorbed by the sea grass. Sea grass the manatees eat.
No one knows why the outbreak is so severe this year. Mike Parsons teaches marine science at Florida Gulf Coast University. He says bad luck is partly why so many manatees have died.
MIKE PARSONS: The bloom is fairly persistent and fairly large, but it's not the worst of blooms. But I think just the way the winds are blowing, it's getting on sea grass beds. It hasn't been so cold that the manatees are going up river, things like that, so they're still staying out feeding. And I think it's just a lot of bad luck.
LOPEZ: The manatee population has rebounded in the past few years. Federal officials believe there are now about 5,000. There had even been debate to downgrade the species from endangered status to threatened. The U.S. Fish and Wildlife Service says this year's rash of deaths may complicate that.
State Wildlife officer Steve Rice says, in the meantime, he is also keeping his eyes peeled for manatees that are sick but not dead yet.
RICE: When we see the one in distress from the red tide, they're struggling to come to the surface trying to breathe and it actually causes seizures. So when we get in the water to try and rescue them, we can feel them seizing as we're holding their head up to help them breathe.
LOPEZ: If manatees are rescued in time, they have a very good chance of recovery at several marine rehabilitation centers around the state. But Rice says that does little to help the record number of manatees that have already died this year in Florida.
For NPR News, I'm Ashley Lopez in Fort Myers.