Manatees in death spiral across Fla.
Scientists say ecological collapse is causing starvation among species
Florida Today USA TODAY NETWORK – FLORIDA
Scientists say Florida’s most beloved marine mammal is starving to death.
On a recent Saturday, the Stasiks witnessed the famine in real time along the banks of Manatee Cove Park on Merritt Island, Florida. The paradise they once padded through in this remote, mangrove- lined cove now looks lost – like an elephant graveyard. Except there are manatee bones that litter the shoreline, not tusks.
Amid the bones lie the remains of a few other gentle marine giants, surrounded by vultures. The 13 carcasses the Stasiks recently counted there represent just one flashpoint in a much larger die-off of Florida’s best-known and beloved marine mammal this year, especially in the Indian River Lagoon.
“This is the worst that I’ve ever seen,” Phil Stasik of Merritt Island said via email.
At least 403 manatees have died in Florida in 2021, four times the five-year average up to this point in the year, according to state wildlife officials.
Cold stress accounted for at least 39 deaths, or about 10%. For 277 others, almost 70%, the cause is unknown. Because of COVID-19 rules, a state lab tasked with examining dead manatees has only been able to salvage and examine 30% of the remains. So they’re left to rot in places like the small spit of land off Manatee Cove. Watercraft collisions have killed 14 so far this year, but typically account for about a quarter of manatee deaths.
Biologists suspected the sea cows are starving to death as the marine mammal’s main diet of seagrass wilts under ongoing yearslong ecological collapse, driven by excess algae.
“They are severely emaciated,” Martinde Wit, a veterinarian with the Florida Fish and Wildlife Conservation Commission, said of the manatees she examined at FWC’s marine pathology lab. “This is not the usual type of animal we see.”
Half of the dead manatees are adults, she said. Their guts are empty, their fat and muscle depleted, their livers atrophied, and they show other signs of starvation.
“It is to an extent that I have not seen before in manatees,” de Wit said. “This is striking.”
The ongoing sea cow starvation comes as a crucial reproductive time approaches,de Wit said, when lactating female manatees need nutrition, as will their young.
Florida wildlife officials have asked the National Oceanic and Atmospheric Administration to declare the die-off an Unusual Marine Mammal Mortality Event, a designation that would trigger a formal federal investigation and funding for the response.
This year’s deaths usher in the year’s long “chicken vs. egg” debate between environment groups and boating advocates. Environment groups emphasize pollution killing seagrass. Boating advocates point to too many manatees being in the wrong places at the wrong cold times, eating seagrass bottoms to moonscapes and leaving behind highnutrient waste that fuels excess algae that blocks sunlight, stopping the grass from growing back.
“This shouldn’t be a surprise,” said Bob Atkins, president of Citizens for Florida’s Waterways, a boating advocacy group based in Brevard.
“Although we call them rivers, the IRL is really more like a lake,” Atkins said. “A ‘closed system.’ Everything flows into it and very little flows out.”
Warm-water discharges from power plants such as the two 1960s-era power plants in Port St. Johns attract manatees to winter and forage seagrass there often beyond what can readily recover.
A state and federal task force has for decades discussed ways to wean manatees off those warm-water discharges but has yet to take concrete action to wean manatees off the power plant discharges. There are 67 known primary and secondary warm-water sites used by manatees in Florida, including 10 power plants, 23 springs and spring complexes, and 34 passive thermal basins, according to the task force’s habitat action plan.
“We have been warning the agencies for years that either we eliminate the artificial warm-water outflows and risk some manatees not returning ... or do nothing and keep stressing the system until the loss of seagrass threatens the life of the IRL itself and everything dies including many more manatees,” Atkins said.
The lagoon does not have “a boundless capacity to support ever-increasing pressure on the vegetative mass,” he said.
De Wit countered that human pollution is responsible for the loss of seagrass, not manatees. De Wit noted the lagoon’s seagrass began plummeting around 2011 after a widespread “superbloom” of algae clouded sunlight from reaching seagrass for months.
Linda Stasik paddles near Manatee Cove Park on Feb. 27, where remains of more than a dozen dead manatees are sprawled along the shore. PHIL STASIK