BREVARD COUNTY, Fla. - Dolphins and manatees are dying in Brevard County's Indian River Lagoon twice as quickly as last year.
They say it may have something to do with the mammals' changing habitat.
Several agencies are joining forces to solve the mystery.
Monday, scientists from Hubbs SeaWorld Research Institute recovered three dead dolphins in Brevard County.
That brought the count to 30 just since the beginning of the year. Even more manatees have died.
For marine biologist Megan Stolen and her coworkers at the institute, there have already been too many calls to Indian River Lagoon to investigate a dolphin death.
"It's especially hard to see young animals die," Stolen said.
Stolen said the dead dolphins they have been finding are "really skinny," but aside from that, have no obvious problems in common.
Biologists have taken tissue samples and tested for toxins, but haven't discovered anything definitive.
"We're not exactly sure what's happening with the pelicans and manatees either," Stolen said.
There have been more than 100 unsolved manatee deaths between last July and this April, enough for the National Oceanic and Atmospheric Administration to declare a marine mammal unusual mortality event.
That triggers an investigation.
Florida Fish and Wildlife thinks algae blooms may have contributed to manatees' deaths.
The blooms can block out sunlight, negatively impacting sea grass growth, a staple of the manatee diet.
Sailor Lloyd Scott has an idea – the callousness and carelessness of human beings.
"We've damaged every environment I've ever seen," Scott said.
Scientists said they don't know if the crisis is natural or man-made.
Stolen said even if they knew what's happening, there may only be so much they could do about it.
"We definitely want to know what's happening, but we may not be able to prevent future deaths," Stolen said.