A thinning sea cow herd

Florida’s manatees are starving to death. According to data from the Florida Fish and Wildlife Conservation Commission, 819 manatees have died so far this year—far outstripping figures from previous years.

Florida wildlife officials point to an ongoing ecological disaster along the state’s Atlantic coast putting extreme pressure on the manatees. Conservationists and the state wildlife agency are working on plans to restore the endangered species’ ecosystem before the population falls too far.

Wildlife officials first noticed the trend late last year, when they began discovering emaciated manatees washed ashore. Some were hundreds of pounds lighter than they should have been. The midyear report released June 25 showed more than 800 Florida manatee fatalities, compared to just 341 during the same period in 2020. More than 6,300 manatees live in the state’s waters, according to the Fish and Wildlife Service.

Authorities blame the manatee deaths on the changing ecology of the Indian River Lagoon, a massive and brackish bayside body of water between mainland Florida and barrier islands on the Atlantic coast. In 2020, the Marine Resources Council gave the 156-mile lagoon system a failing grade for habitat quality, singling out the system’s southern portion in St. Lucie and Martin counties as “extremely poor.”

The water quality doesn’t hurt the manatees directly, but it devastates the aquatic mammals’ menu options. Manatees, sometimes known as sea cows for their leisurely grazing habits, have historically wintered in the warmer waters of the lagoon, feasting on its plentiful seagrass.

But beginning in 2011, a group of scientists blamed a sunlight-blocking algae bloom in the lagoon for killing off 60 percent of the ecosystem’s seagrass. Since then sewer runoff and discharges from Lake Okeechobee further inhibited the seagrass’s recovery. “We have a compromised system that the animals have to utilize and stay in,” University of Florida aquatic animal expert Michael Walsh told NPR. “But the food is not there in the same amount it used to be.”

To help rebuild the ecology of the manatees’ winter home, the Florida legislature voted to devote $500 million of federal stimulus money to convert septic systems into more environmentally friendly sewage systems. And a private group, buoyed by federal grants, have begun replanting acres of a resilient seagrass species to try and prevent another mass starvation event next winter.